diff options
| -rw-r--r-- | Documentation/pinctrl.txt | 950 | ||||
| -rw-r--r-- | MAINTAINERS | 5 | ||||
| -rw-r--r-- | drivers/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/Makefile | 2 | ||||
| -rw-r--r-- | drivers/pinctrl/Kconfig | 29 | ||||
| -rw-r--r-- | drivers/pinctrl/Makefile | 6 | ||||
| -rw-r--r-- | drivers/pinctrl/core.c | 599 | ||||
| -rw-r--r-- | drivers/pinctrl/core.h | 72 | ||||
| -rw-r--r-- | drivers/pinctrl/pinmux.c | 1180 | ||||
| -rw-r--r-- | drivers/pinctrl/pinmux.h | 47 | ||||
| -rw-r--r-- | include/linux/pinctrl/machine.h | 107 | ||||
| -rw-r--r-- | include/linux/pinctrl/pinctrl.h | 133 | ||||
| -rw-r--r-- | include/linux/pinctrl/pinmux.h | 117 |
13 files changed, 3249 insertions, 0 deletions
diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt new file mode 100644 index 0000000..b04cb7d --- /dev/null +++ b/Documentation/pinctrl.txt @@ -0,0 +1,950 @@ +PINCTRL (PIN CONTROL) subsystem +This document outlines the pin control subsystem in Linux + +This subsystem deals with: + +- Enumerating and naming controllable pins + +- Multiplexing of pins, pads, fingers (etc) see below for details + +The intention is to also deal with: + +- Software-controlled biasing and driving mode specific pins, such as + pull-up/down, open drain etc, load capacitance configuration when controlled + by software, etc. + + +Top-level interface +=================== + +Definition of PIN CONTROLLER: + +- A pin controller is a piece of hardware, usually a set of registers, that + can control PINs. It may be able to multiplex, bias, set load capacitance, + set drive strength etc for individual pins or groups of pins. + +Definition of PIN: + +- PINS are equal to pads, fingers, balls or whatever packaging input or + output line you want to control and these are denoted by unsigned integers + in the range 0..maxpin. This numberspace is local to each PIN CONTROLLER, so + there may be several such number spaces in a system. This pin space may + be sparse - i.e. there may be gaps in the space with numbers where no + pin exists. + +When a PIN CONTROLLER is instatiated, it will register a descriptor to the +pin control framework, and this descriptor contains an array of pin descriptors +describing the pins handled by this specific pin controller. + +Here is an example of a PGA (Pin Grid Array) chip seen from underneath: + + A B C D E F G H + + 8 o o o o o o o o + + 7 o o o o o o o o + + 6 o o o o o o o o + + 5 o o o o o o o o + + 4 o o o o o o o o + + 3 o o o o o o o o + + 2 o o o o o o o o + + 1 o o o o o o o o + +To register a pin controller and name all the pins on this package we can do +this in our driver: + +#include <linux/pinctrl/pinctrl.h> + +const struct pinctrl_pin_desc __refdata foo_pins[] = { + PINCTRL_PIN(0, "A1"), + PINCTRL_PIN(1, "A2"), + PINCTRL_PIN(2, "A3"), + ... + PINCTRL_PIN(61, "H6"), + PINCTRL_PIN(62, "H7"), + PINCTRL_PIN(63, "H8"), +}; + +static struct pinctrl_desc foo_desc = { + .name = "foo", + .pins = foo_pins, + .npins = ARRAY_SIZE(foo_pins), + .maxpin = 63, + .owner = THIS_MODULE, +}; + +int __init foo_probe(void) +{ + struct pinctrl_dev *pctl; + + pctl = pinctrl_register(&foo_desc, <PARENT>, NULL); + if (IS_ERR(pctl)) + pr_err("could not register foo pin driver\n"); +} + +Pins usually have fancier names than this. You can find these in the dataheet +for your chip. Notice that the core pinctrl.h file provides a fancy macro +called PINCTRL_PIN() to create the struct entries. As you can see I enumerated +the pins from 0 in the upper left corner to 63 in the lower right corner, +this enumeration was arbitrarily chosen, in practice you need to think +through your numbering system so that it matches the layout of registers +and such things in your driver, or the code may become complicated. You must +also consider matching of offsets to the GPIO ranges that may be handled by +the pin controller. + +For a padring with 467 pads, as opposed to actual pins, I used an enumeration +like this, walking around the edge of the chip, which seems to be industry +standard too (all these pads had names, too): + + + 0 ..... 104 + 466 105 + . . + . . + 358 224 + 357 .... 225 + + +Pin groups +========== + +Many controllers need to deal with groups of pins, so the pin controller +subsystem has a mechanism for enumerating groups of pins and retrieving the +actual enumerated pins that are part of a certain group. + +For example, say that we have a group of pins dealing with an SPI interface +on { 0, 8, 16, 24 }, and a group of pins dealing with an I2C interface on pins +on { 24, 25 }. + +These two groups are presented to the pin control subsystem by implementing +some generic pinctrl_ops like this: + +#include <linux/pinctrl/pinctrl.h> + +struct foo_group { + const char *name; + const unsigned int *pins; + const unsigned num_pins; +}; + +static unsigned int spi0_pins[] = { 0, 8, 16, 24 }; +static unsigned int i2c0_pins[] = { 24, 25 }; + +static const struct foo_group foo_groups[] = { + { + .name = "spi0_grp", + .pins = spi0_pins, + .num_pins = ARRAY_SIZE(spi0_pins), + }, + { + .name = "i2c0_grp", + .pins = i2c0_pins, + .num_pins = ARRAY_SIZE(i2c0_pins), + }, +}; + + +static int foo_list_groups(struct pinctrl_dev *pctldev, unsigned selector) +{ + if (selector >= ARRAY_SIZE(foo_groups)) + return -EINVAL; + return 0; +} + +static const char *foo_get_group_name(struct pinctrl_dev *pctldev, + unsigned selector) +{ + return foo_groups[selector].name; +} + +static int foo_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector, + unsigned ** const pins, + unsigned * const num_pins) +{ + *pins = (unsigned *) foo_groups[selector].pins; + *num_pins = foo_groups[selector].num_pins; + return 0; +} + +static struct pinctrl_ops foo_pctrl_ops = { + .list_groups = foo_list_groups, + .get_group_name = foo_get_group_name, + .get_group_pins = foo_get_group_pins, +}; + + +static struct pinctrl_desc foo_desc = { + ... + .pctlops = &foo_pctrl_ops, +}; + +The pin control subsystem will call the .list_groups() function repeatedly +beginning on 0 until it returns non-zero to determine legal selectors, then +it will call the other functions to retrieve the name and pins of the group. +Maintaining the data structure of the groups is up to the driver, this is +just a simple example - in practice you may need more entries in your group +structure, for example specific register ranges associated with each group +and so on. + + +Interaction with the GPIO subsystem +=================================== + +The GPIO drivers may want to perform operations of various types on the same +physical pins that are also registered as pin controller pins. + +Since the pin controller subsystem have its pinspace local to the pin +controller we need a mapping so that the pin control subsystem can figure out +which pin controller handles control of a certain GPIO pin. Since a single +pin controller may be muxing several GPIO ranges (typically SoCs that have +one set of pins but internally several GPIO silicon blocks, each modeled as +a struct gpio_chip) any number of GPIO ranges can be added to a pin controller +instance like this: + +struct gpio_chip chip_a; +struct gpio_chip chip_b; + +static struct pinctrl_gpio_range gpio_range_a = { + .name = "chip a", + .id = 0, + .base = 32, + .npins = 16, + .gc = &chip_a; +}; + +static struct pinctrl_gpio_range gpio_range_a = { + .name = "chip b", + .id = 0, + .base = 48, + .npins = 8, + .gc = &chip_b; +}; + + +{ + struct pinctrl_dev *pctl; + ... + pinctrl_add_gpio_range(pctl, &gpio_range_a); + pinctrl_add_gpio_range(pctl, &gpio_range_b); +} + +So this complex system has one pin controller handling two different +GPIO chips. Chip a has 16 pins and chip b has 8 pins. They are mapped in +the global GPIO pin space at: + +chip a: [32 .. 47] +chip b: [48 .. 55] + +When GPIO-specific functions in the pin control subsystem are called, these +ranges will be used to look up the apropriate pin controller by inspecting +and matching the pin to the pin ranges across all controllers. When a +pin controller handling the matching range is found, GPIO-specific functions +will be called on that specific pin controller. + +For all functionalities dealing with pin biasing, pin muxing etc, the pin +controller subsystem will subtract the range's .base offset from the passed +in gpio pin number, and pass that on to the pin control driver, so the driver +will get an offset into its handled number range. Further it is also passed +the range ID value, so that the pin controller knows which range it should +deal with. + +For example: if a user issues pinctrl_gpio_set_foo(50), the pin control +subsystem will find that the second range on this pin controller matches, +subtract the base 48 and call the +pinctrl_driver_gpio_set_foo(pinctrl, range, 2) where the latter function has +this signature: + +int pinctrl_driver_gpio_set_foo(struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *rangeid, + unsigned offset); + +Now the driver knows that we want to do some GPIO-specific operation on the +second GPIO range handled by "chip b", at offset 2 in that specific range. + +(If the GPIO subsystem is ever refactored to use a local per-GPIO controller +pin space, this mapping will need to be augmented accordingly.) + + +PINMUX interfaces +================= + +These calls use the pinmux_* naming prefix. No other calls should use that +prefix. + + +What is pinmuxing? +================== + +PINMUX, also known as padmux, ballmux, alternate functions or mission modes +is a way for chip vendors producing some kind of electrical packages to use +a certain physical pin (ball, pad, finger, etc) for multiple mutually exclusive +functions, depending on the application. By "application" in this context +we usually mean a way of soldering or wiring the package into an electronic +system, even though the framework makes it possible to also change the function +at runtime. + +Here is an example of a PGA (Pin Grid Array) chip seen from underneath: + + A B C D E F G H + +---+ + 8 | o | o o o o o o o + | | + 7 | o | o o o o o o o + | | + 6 | o | o o o o o o o + +---+---+ + 5 | o | o | o o o o o o + +---+---+ +---+ + 4 o o o o o o | o | o + | | + 3 o o o o o o | o | o + | | + 2 o o o o o o | o | o + +-------+-------+-------+---+---+ + 1 | o o | o o | o o | o | o | + +-------+-------+-------+---+---+ + +This is not tetris. The game to think of is chess. Not all PGA/BGA packages +are chessboard-like, big ones have "holes" in some arrangement according to +different design patterns, but we're using this as a simple example. Of the +pins you see some will be taken by things like a few VCC and GND to feed power +to the chip, and quite a few will be taken by large ports like an external +memory interface. The remaining pins will often be subject to pin multiplexing. + +The example 8x8 PGA package above will have pin numbers 0 thru 63 assigned to +its physical pins. It will name the pins { A1, A2, A3 ... H6, H7, H8 } using +pinctrl_register_pins() and a suitable data set as shown earlier. + +In this 8x8 BGA package the pins { A8, A7, A6, A5 } can be used as an SPI port +(these are four pins: CLK, RXD, TXD, FRM). In that case, pin B5 can be used as +some general-purpose GPIO pin. However, in another setting, pins { A5, B5 } can +be used as an I2C port (these are just two pins: SCL, SDA). Needless to say, +we cannot use the SPI port and I2C port at the same time. However in the inside +of the package the silicon performing the SPI logic can alternatively be routed +out on pins { G4, G3, G2, G1 }. + +On the botton row at { A1, B1, C1, D1, E1, F1, G1, H1 } we have something +special - it's an external MMC bus that can be 2, 4 or 8 bits wide, and it will +consume 2, 4 or 8 pins respectively, so either { A1, B1 } are taken or +{ A1, B1, C1, D1 } or all of them. If we use all 8 bits, we cannot use the SPI +port on pins { G4, G3, G2, G1 } of course. + +This way the silicon blocks present inside the chip can be multiplexed "muxed" +out on different pin ranges. Often contemporary SoC (systems on chip) will +contain several I2C, SPI, SDIO/MMC, etc silicon blocks that can be routed to +different pins by pinmux settings. + +Since general-purpose I/O pins (GPIO) are typically always in shortage, it is +common to be able to use almost any pin as a GPIO pin if it is not currently +in use by some other I/O port. + + +Pinmux conventions +================== + +The purpose of the pinmux functionality in the pin controller subsystem is to +abstract and provide pinmux settings to the devices you choose to instantiate +in your machine configuration. It is inspired by the clk, GPIO and regulator +subsystems, so devices will request their mux setting, but it's also possible +to request a single pin for e.g. GPIO. + +Definitions: + +- FUNCTIONS can be switched in and out by a driver residing with the pin + control subsystem in the drivers/pinctrl/* directory of the kernel. The + pin control driver knows the possible functions. In the example above you can + identify three pinmux functions, one for spi, one for i2c and one for mmc. + +- FUNCTIONS are assumed to be enumerable from zero in a one-dimensional array. + In this case the array could be something like: { spi0, i2c0, mmc0 } + for the three available functions. + +- FUNCTIONS have PIN GROUPS as defined on the generic level - so a certain + function is *always* associated with a certain set of pin groups, could + be just a single one, but could also be many. In the example above the + function i2c is associated with the pins { A5, B5 }, enumerated as + { 24, 25 } in the controller pin space. + + The Function spi is associated with pin groups { A8, A7, A6, A5 } + and { G4, G3, G2, G1 }, which are enumerated as { 0, 8, 16, 24 } and + { 38, 46, 54, 62 } respectively. + + Group names must be unique per pin controller, no two groups on the same + controller may have the same name. + +- The combination of a FUNCTION and a PIN GROUP determine a certain function + for a certain set of pins. The knowledge of the functions and pin groups + and their machine-specific particulars are kept inside the pinmux driver, + from the outside only the enumerators are known, and the driver core can: + + - Request the name of a function with a certain selector (>= 0) + - A list of groups associated with a certain function + - Request that a certain group in that list to be activated for a certain + function + + As already described above, pin groups are in turn self-descriptive, so + the core will retrieve the actual pin range in a certain group from the + driver. + +- FUNCTIONS and GROUPS on a certain PIN CONTROLLER are MAPPED to a certain + device by the board file, device tree or similar machine setup configuration + mechanism, similar to how regulators are connected to devices, usually by + name. Defining a pin controller, function and group thus uniquely identify + the set of pins to be used by a certain device. (If only one possible group + of pins is available for the function, no group name need to be supplied - + the core will simply select the first and only group available.) + + In the example case we can define that this particular machine shall + use device spi0 with pinmux function fspi0 group gspi0 and i2c0 on function + fi2c0 group gi2c0, on the primary pin controller, we get mappings + like these: + + { + {"map-spi0", spi0, pinctrl0, fspi0, gspi0}, + {"map-i2c0", i2c0, pinctrl0, fi2c0, gi2c0} + } + + Every map must be assigned a symbolic name, pin controller and function. + The group is not compulsory - if it is omitted the first group presented by + the driver as applicable for the function will be selected, which is + useful for simple cases. + + The device name is present in map entries tied to specific devices. Maps + without device names are referred to as SYSTEM pinmuxes, such as can be taken + by the machine implementation on boot and not tied to any specific device. + + It is possible to map several groups to the same combination of device, + pin controller and function. This is for cases where a certain function on + a certain pin controller may use different sets of pins in different + configurations. + +- PINS for a certain FUNCTION using a certain PIN GROUP on a certain + PIN CONTROLLER are provided on a first-come first-serve basis, so if some + other device mux setting or GPIO pin request has already taken your physical + pin, you will be denied the use of it. To get (activate) a new setting, the + old one has to be put (deactivated) first. + +Sometimes the documentation and hardware registers will be oriented around +pads (or "fingers") rather than pins - these are the soldering surfaces on the +silicon inside the package, and may or may not match the actual number of +pins/balls underneath the capsule. Pick some enumeration that makes sense to +you. Define enumerators only for the pins you can control if that makes sense. + +Assumptions: + +We assume that the number possible function maps to pin groups is limited by +the hardware. I.e. we assume that there is no system where any function can be +mapped to any pin, like in a phone exchange. So the available pins groups for +a certain function will be limited to a few choices (say up to eight or so), +not hundreds or any amount of choices. This is the characteristic we have found +by inspecting available pinmux hardware, and a necessary assumption since we +expect pinmux drivers to present *all* possible function vs pin group mappings +to the subsystem. + + +Pinmux drivers +============== + +The pinmux core takes care of preventing conflicts on pins and calling +the pin controller driver to execute different settings. + +It is the responsibility of the pinmux driver to impose further restrictions +(say for example infer electronic limitations due to load etc) to determine +whether or not the requested function can actually be allowed, and in case it +is possible to perform the requested mux setting, poke the hardware so that +this happens. + +Pinmux drivers are required to supply a few callback functions, some are +optional. Usually the enable() and disable() functions are implemented, +writing values into some certain registers to activate a certain mux setting +for a certain pin. + +A simple driver for the above example will work by setting bits 0, 1, 2, 3 or 4 +into some register named MUX to select a certain function with a certain +group of pins would work something like this: + +#include <linux/pinctrl/pinctrl.h> +#include <linux/pinctrl/pinmux.h> + +struct foo_group { + const char *name; + const unsigned int *pins; + const unsigned num_pins; +}; + +static const unsigned spi0_0_pins[] = { 0, 8, 16, 24 }; +static const unsigned spi0_1_pins[] = { 38, 46, 54, 62 }; +static const unsigned i2c0_pins[] = { 24, 25 }; +static const unsigned mmc0_1_pins[] = { 56, 57 }; +static const unsigned mmc0_2_pins[] = { 58, 59 }; +static const unsigned mmc0_3_pins[] = { 60, 61, 62, 63 }; + +static const struct foo_group foo_groups[] = { + { + .name = "spi0_0_grp", + .pins = spi0_0_pins, + .num_pins = ARRAY_SIZE(spi0_0_pins), + }, + { + .name = "spi0_1_grp", + .pins = spi0_1_pins, + .num_pins = ARRAY_SIZE(spi0_1_pins), + }, + { + .name = "i2c0_grp", + .pins = i2c0_pins, + .num_pins = ARRAY_SIZE(i2c0_pins), + }, + { + .name = "mmc0_1_grp", + .pins = mmc0_1_pins, + .num_pins = ARRAY_SIZE(mmc0_1_pins), + }, + { + .name = "mmc0_2_grp", + .pins = mmc0_2_pins, + .num_pins = ARRAY_SIZE(mmc0_2_pins), + }, + { + .name = "mmc0_3_grp", + .pins = mmc0_3_pins, + .num_pins = ARRAY_SIZE(mmc0_3_pins), + }, +}; + + +static int foo_list_groups(struct pinctrl_dev *pctldev, unsigned selector) +{ + if (selector >= ARRAY_SIZE(foo_groups)) + return -EINVAL; + return 0; +} + +static const char *foo_get_group_name(struct pinctrl_dev *pctldev, + unsigned selector) +{ + return foo_groups[selector].name; +} + +static int foo_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector, + unsigned ** const pins, + unsigned * const num_pins) +{ + *pins = (unsigned *) foo_groups[selector].pins; + *num_pins = foo_groups[selector].num_pins; + return 0; +} + +static struct pinctrl_ops foo_pctrl_ops = { + .list_groups = foo_list_groups, + .get_group_name = foo_get_group_name, + .get_group_pins = foo_get_group_pins, +}; + +struct foo_pmx_func { + const char *name; + const char * const *groups; + const unsigned num_groups; +}; + +static const char * const spi0_groups[] = { "spi0_1_grp" }; +static const char * const i2c0_groups[] = { "i2c0_grp" }; +static const char * const mmc0_groups[] = { "mmc0_1_grp", "mmc0_2_grp", + "mmc0_3_grp" }; + +static const struct foo_pmx_func foo_functions[] = { + { + .name = "spi0", + .groups = spi0_groups, + .num_groups = ARRAY_SIZE(spi0_groups), + }, + { + .name = "i2c0", + .groups = i2c0_groups, + .num_groups = ARRAY_SIZE(i2c0_groups), + }, + { + .name = "mmc0", + .groups = mmc0_groups, + .num_groups = ARRAY_SIZE(mmc0_groups), + }, +}; + +int foo_list_funcs(struct pinctrl_dev *pctldev, unsigned selector) +{ + if (selector >= ARRAY_SIZE(foo_functions)) + return -EINVAL; + return 0; +} + +const char *foo_get_fname(struct pinctrl_dev *pctldev, unsigned selector) +{ + return myfuncs[selector].name; +} + +static int foo_get_groups(struct pinctrl_dev *pctldev, unsigned selector, + const char * const **groups, + unsigned * const num_groups) +{ + *groups = foo_functions[selector].groups; + *num_groups = foo_functions[selector].num_groups; + return 0; +} + +int foo_enable(struct pinctrl_dev *pctldev, unsigned selector, + unsigned group) +{ + u8 regbit = (1 << group); + + writeb((readb(MUX)|regbit), MUX) + return 0; +} + +int foo_disable(struct pinctrl_dev *pctldev, unsigned selector, + unsigned group) +{ + u8 regbit = (1 << group); + + writeb((readb(MUX) & ~(regbit)), MUX) + return 0; +} + +struct pinmux_ops foo_pmxops = { + .list_functions = foo_list_funcs, + .get_function_name = foo_get_fname, + .get_function_groups = foo_get_groups, + .enable = foo_enable, + .disable = foo_disable, +}; + +/* Pinmux operations are handled by some pin controller */ +static struct pinctrl_desc foo_desc = { + ... + .pctlops = &foo_pctrl_ops, + .pmxops = &foo_pmxops, +}; + +In the example activating muxing 0 and 1 at the same time setting bits +0 and 1, uses one pin in common so they would collide. + +The beauty of the pinmux subsystem is that since it keeps track of all +pins and who is using them, it will already have denied an impossible +request like that, so the driver does not need to worry about such +things - when it gets a selector passed in, the pinmux subsystem makes +sure no other device or GPIO assignment is already using the selected +pins. Thus bits 0 and 1 in the control register will never be set at the +same time. + +All the above functions are mandatory to implement for a pinmux driver. + + +Pinmux interaction with the GPIO subsystem +========================================== + +The function list could become long, especially if you can convert every +individual pin into a GPIO pin independent of any other pins, and then try +the approach to define every pin as a function. + +In this case, the function array would become 64 entries for each GPIO +setting and then the device functions. + +For this reason there is an additional function a pinmux driver can implement +to enable only GPIO on an individual pin: .gpio_request_enable(). The same +.free() function as for other functions is assumed to be usable also for +GPIO pins. + +This function will pass in the affected GPIO range identified by the pin +controller core, so you know which GPIO pins are being affected by the request +operation. + +Alternatively it is fully allowed to use named functions for each GPIO +pin, the pinmux_request_gpio() will attempt to obtain the function "gpioN" +where "N" is the global GPIO pin number if no special GPIO-handler is +registered. + + +Pinmux board/machine configuration +================================== + +Boards and machines define how a certain complete running system is put +together, including how GPIOs and devices are muxed, how regulators are +constrained and how the clock tree looks. Of course pinmux settings are also +part of this. + +A pinmux config for a machine looks pretty much like a simple regulator +configuration, so for the example array above we want to enable i2c and +spi on the second function mapping: + +#include <linux/pinctrl/machine.h> + +static struct pinmux_map pmx_mapping[] = { + { + .ctrl_dev_name = "pinctrl.0", + .function = "spi0", + .dev_name = "foo-spi.0", + }, + { + .ctrl_dev_name = "pinctrl.0", + .function = "i2c0", + .dev_name = "foo-i2c.0", + }, + { + .ctrl_dev_name = "pinctrl.0", + .function = "mmc0", + .dev_name = "foo-mmc.0", + }, +}; + +The dev_name here matches to the unique device name that can be used to look +up the device struct (just like with clockdev or regulators). The function name +must match a function provided by the pinmux driver handling this pin range. + +As you can see we may have several pin controllers on the system and thus +we need to specify which one of them that contain the functions we wish +to map. The map can also use struct device * directly, so there is no +inherent need to use strings to specify .dev_name or .ctrl_dev_name, these +are for the situation where you do not have a handle to the struct device *, +for example if they are not yet instantiated or cumbersome to obtain. + +You register this pinmux mapping to the pinmux subsystem by simply: + + ret = pinmux_register_mappings(&pmx_mapping, ARRAY_SIZE(pmx_mapping)); + +Since the above construct is pretty common there is a helper macro to make +it even more compact which assumes you want to use pinctrl.0 and position +0 for mapping, for example: + +static struct pinmux_map pmx_mapping[] = { + PINMUX_MAP_PRIMARY("I2CMAP", "i2c0", "foo-i2c.0"), +}; + + +Complex mappings +================ + +As it is possible to map a function to different groups of pins an optional +.group can be specified like this: + +... +{ + .name = "spi0-pos-A", + .ctrl_dev_name = "pinctrl.0", + .function = "spi0", + .group = "spi0_0_grp", + .dev_name = "foo-spi.0", +}, +{ + .name = "spi0-pos-B", + .ctrl_dev_name = "pinctrl.0", + .function = "spi0", + .group = "spi0_1_grp", + .dev_name = "foo-spi.0", +}, +... + +This example mapping is used to switch between two positions for spi0 at +runtime, as described further below under the heading "Runtime pinmuxing". + +Further it is possible to match several groups of pins to the same function +for a single device, say for example in the mmc0 example above, where you can +additively expand the mmc0 bus from 2 to 4 to 8 pins. If we want to use all +three groups for a total of 2+2+4 = 8 pins (for an 8-bit MMC bus as is the +case), we define a mapping like this: + +... +{ + .name "2bit" + .ctrl_dev_name = "pinctrl.0", + .function = "mmc0", + .group = "mmc0_0_grp", + .dev_name = "foo-mmc.0", +}, +{ + .name "4bit" + .ctrl_dev_name = "pinctrl.0", + .function = "mmc0", + .group = "mmc0_0_grp", + .dev_name = "foo-mmc.0", +}, +{ + .name "4bit" + .ctrl_dev_name = "pinctrl.0", + .function = "mmc0", + .group = "mmc0_1_grp", + .dev_name = "foo-mmc.0", +}, +{ + .name "8bit" + .ctrl_dev_name = "pinctrl.0", + .function = "mmc0", + .group = "mmc0_0_grp", + .dev_name = "foo-mmc.0", +}, +{ + .name "8bit" + .ctrl_dev_name = "pinctrl.0", + .function = "mmc0", + .group = "mmc0_1_grp", + .dev_name = "foo-mmc.0", +}, +{ + .name "8bit" + .ctrl_dev_name = "pinctrl.0", + .function = "mmc0", + .group = "mmc0_2_grp", + .dev_name = "foo-mmc.0", +}, +... + +The result of grabbing this mapping from the device with something like +this (see next paragraph): + + pmx = pinmux_get(&device, "8bit"); + +Will be that you activate all the three bottom records in the mapping at +once. Since they share the same name, pin controller device, funcion and +device, and since we allow multiple groups to match to a single device, they +all get selected, and they all get enabled and disable simultaneously by the +pinmux core. + + +Pinmux requests from drivers +============================ + +Generally it is discouraged to let individual drivers get and enable pinmuxes. +So if possible, handle the pinmuxes in platform code or some other place where +you have access to all the affected struct device * pointers. In some cases +where a driver needs to switch between different mux mappings at runtime +this is not possible. + +A driver may request a certain mux to be activated, usually just the default +mux like this: + +#include <linux/pinctrl/pinmux.h> + +struct foo_state { + struct pinmux *pmx; + ... +}; + +foo_probe() +{ + /* Allocate a state holder named "state" etc */ + struct pinmux pmx; + + pmx = pinmux_get(&device, NULL); + if IS_ERR(pmx) + return PTR_ERR(pmx); + pinmux_enable(pmx); + + state->pmx = pmx; +} + +foo_remove() +{ + pinmux_disable(state->pmx); + pinmux_put(state->pmx); +} + +If you want to grab a specific mux mapping and not just the first one found for +this device you can specify a specific mapping name, for example in the above +example the second i2c0 setting: pinmux_get(&device, "spi0-pos-B"); + +This get/enable/disable/put sequence can just as well be handled by bus drivers +if you don't want each and every driver to handle it and you know the +arrangement on your bus. + +The semantics of the get/enable respective disable/put is as follows: + +- pinmux_get() is called in process context to reserve the pins affected with + a certain mapping and set up the pinmux core and the driver. It will allocate + a struct from the kernel memory to hold the pinmux state. + +- pinmux_enable()/pinmux_disable() is quick and can be called from fastpath + (irq context) when you quickly want to set up/tear down the hardware muxing + when running a device driver. Usually it will just poke some values into a + register. + +- pinmux_disable() is called in process context to tear down the pin requests + and release the state holder struct for the mux setting. + +Usually the pinmux core handled the get/put pair and call out to the device +drivers bookkeeping operations, like checking available functions and the +associated pins, whereas the enable/disable pass on to the pin controller +driver which takes care of activating and/or deactivating the mux setting by +quickly poking some registers. + +The pins are allocated for your device when you issue the pinmux_get() call, +after this you should be able to see this in the debugfs listing of all pins. + + +System pinmux hogging +===================== + +A system pinmux map entry, i.e. a pinmux setting that does not have a device +associated with it, can be hogged by the core when the pin controller is +registered. This means that the core will attempt to call pinmux_get() and +pinmux_enable() on it immediately after the pin control device has been +registered. + +This is enabled by simply setting the .hog_on_boot field in the map to true, +like this: + +{ + .name "POWERMAP" + .ctrl_dev_name = "pinctrl.0", + .function = "power_func", + .hog_on_boot = true, +}, + +Since it may be common to request the core to hog a few always-applicable +mux settings on the primary pin controller, there is a convenience macro for +this: + +PINMUX_MAP_PRIMARY_SYS_HOG("POWERMAP", "power_func") + +This gives the exact same result as the above construction. + + +Runtime pinmuxing +================= + +It is possible to mux a certain function in and out at runtime, say to move +an SPI port from one set of pins to another set of pins. Say for example for +spi0 in the example above, we expose two different groups of pins for the same +function, but with different named in the mapping as described under +"Advanced mapping" above. So we have two mappings named "spi0-pos-A" and +"spi0-pos-B". + +This snippet first muxes the function in the pins defined by group A, enables +it, disables and releases it, and muxes it in on the pins defined by group B: + +foo_switch() +{ + struct pinmux pmx; + + /* Enable on position A */ + pmx = pinmux_get(&device, "spi0-pos-A"); + if IS_ERR(pmx) + return PTR_ERR(pmx); + pinmux_enable(pmx); + + /* This releases the pins again */ + pinmux_disable(pmx); + pinmux_put(pmx); + + /* Enable on position B */ + pmx = pinmux_get(&device, "spi0-pos-B"); + if IS_ERR(pmx) + return PTR_ERR(pmx); + pinmux_enable(pmx); + ... +} + +The above has to be done from process context. diff --git a/MAINTAINERS b/MAINTAINERS index ae8820e..e113be5 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5010,6 +5010,11 @@ L: linux-mtd@lists.infradead.org S: Maintained F: drivers/mtd/devices/phram.c +PIN CONTROL SUBSYSTEM +M: Linus Walleij <linus.walleij@linaro.org> +S: Maintained +F: drivers/pinmux/ + PKTCDVD DRIVER M: Peter Osterlund <petero2@telia.com> S: Maintained diff --git a/drivers/Kconfig b/drivers/Kconfig index 95b9e7e..e73aaae 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -56,6 +56,8 @@ source "drivers/pps/Kconfig" source "drivers/ptp/Kconfig" +source "drivers/pinctrl/Kconfig" + source "drivers/gpio/Kconfig" source "drivers/w1/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 7fa433a..e7afb3a 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -5,6 +5,8 @@ # Rewritten to use lists instead of if-statements. # +# GPIO must come after pinctrl as gpios may need to mux pins etc +obj-y += pinctrl/ obj-y += gpio/ obj-$(CONFIG_PCI) += pci/ obj-$(CONFIG_PARISC) += parisc/ diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig new file mode 100644 index 0000000..02b4d4e --- /dev/null +++ b/drivers/pinctrl/Kconfig @@ -0,0 +1,29 @@ +# +# PINCTRL infrastructure and drivers +# + +menuconfig PINCTRL + bool "PINCTRL Support" + depends on EXPERIMENTAL + help + This enables the PINCTRL subsystem for controlling pins + on chip packages, for example multiplexing pins on primarily + PGA and BGA packages for systems on chip. + + If unsure, say N. + +if PINCTRL + +config PINMUX + bool "Support pinmux controllers" + help + Say Y here if you want the pincontrol subsystem to handle pin + multiplexing drivers. + +config DEBUG_PINCTRL + bool "Debug PINCTRL calls" + depends on DEBUG_KERNEL + help + Say Y here to add some extra checks and diagnostics to PINCTRL calls. + +endif diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile new file mode 100644 index 0000000..596ce9f --- /dev/null +++ b/drivers/pinctrl/Makefile @@ -0,0 +1,6 @@ +# generic pinmux support + +ccflags-$(CONFIG_DEBUG_PINMUX) += -DDEBUG + +obj-$(CONFIG_PINCTRL) += core.o +obj-$(CONFIG_PINMUX) += pinmux.o diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c new file mode 100644 index 0000000..b2eaf8d --- /dev/null +++ b/drivers/pinctrl/core.c @@ -0,0 +1,599 @@ +/* + * Core driver for the pin control subsystem + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * Based on bits of regulator core, gpio core and clk core + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ +#define pr_fmt(fmt) "pinctrl core: " fmt + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/radix-tree.h> +#include <linux/err.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/spinlock.h> +#include <linux/sysfs.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <linux/pinctrl/pinctrl.h> +#include <linux/pinctrl/machine.h> +#include "core.h" +#include "pinmux.h" + +/* Global list of pin control devices */ +static DEFINE_MUTEX(pinctrldev_list_mutex); +static LIST_HEAD(pinctrldev_list); + +static void pinctrl_dev_release(struct device *dev) +{ + struct pinctrl_dev *pctldev = dev_get_drvdata(dev); + kfree(pctldev); +} + +const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev) +{ + /* We're not allowed to register devices without name */ + return pctldev->desc->name; +} +EXPORT_SYMBOL_GPL(pinctrl_dev_get_name); + +void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev) +{ + return pctldev->driver_data; +} +EXPORT_SYMBOL_GPL(pinctrl_dev_get_drvdata); + +/** + * get_pinctrl_dev_from_dev() - look up pin controller device + * @dev: a device pointer, this may be NULL but then devname needs to be + * defined instead + * @devname: the name of a device instance, as returned by dev_name(), this + * may be NULL but then dev needs to be defined instead + * + * Looks up a pin control device matching a certain device name or pure device + * pointer, the pure device pointer will take precedence. + */ +struct pinctrl_dev *get_pinctrl_dev_from_dev(struct device *dev, + const char *devname) +{ + struct pinctrl_dev *pctldev = NULL; + bool found = false; + + mutex_lock(&pinctrldev_list_mutex); + list_for_each_entry(pctldev, &pinctrldev_list, node) { + if (dev && &pctldev->dev == dev) { + /* Matched on device pointer */ + found = true; + break; + } + + if (devname && + !strcmp(dev_name(&pctldev->dev), devname)) { + /* Matched on device name */ + found = true; + break; + } + } + mutex_unlock(&pinctrldev_list_mutex); + + return found ? pctldev : NULL; +} + +struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, int pin) +{ + struct pin_desc *pindesc; + unsigned long flags; + + spin_lock_irqsave(&pctldev->pin_desc_tree_lock, flags); + pindesc = radix_tree_lookup(&pctldev->pin_desc_tree, pin); + spin_unlock_irqrestore(&pctldev->pin_desc_tree_lock, flags); + + return pindesc; +} + +/** + * pin_is_valid() - check if pin exists on controller + * @pctldev: the pin control device to check the pin on + * @pin: pin to check, use the local pin controller index number + * + * This tells us whether a certain pin exist on a certain pin controller or + * not. Pin lists may be sparse, so some pins may not exist. + */ +bool pin_is_valid(struct pinctrl_dev *pctldev, int pin) +{ + struct pin_desc *pindesc; + + if (pin < 0) + return false; + + pindesc = pin_desc_get(pctldev, pin); + if (pindesc == NULL) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(pin_is_valid); + +/* Deletes a range of pin descriptors */ +static void pinctrl_free_pindescs(struct pinctrl_dev *pctldev, + const struct pinctrl_pin_desc *pins, + unsigned num_pins) +{ + int i; + + spin_lock(&pctldev->pin_desc_tree_lock); + for (i = 0; i < num_pins; i++) { + struct pin_desc *pindesc; + + pindesc = radix_tree_lookup(&pctldev->pin_desc_tree, + pins[i].number); + if (pindesc != NULL) { + radix_tree_delete(&pctldev->pin_desc_tree, + pins[i].number); + } + kfree(pindesc); + } + spin_unlock(&pctldev->pin_desc_tree_lock); +} + +static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev, + unsigned number, const char *name) +{ + struct pin_desc *pindesc; + + pindesc = pin_desc_get(pctldev, number); + if (pindesc != NULL) { + pr_err("pin %d already registered on %s\n", number, + pctldev->desc->name); + return -EINVAL; + } + + pindesc = kzalloc(sizeof(*pindesc), GFP_KERNEL); + if (pindesc == NULL) + return -ENOMEM; + spin_lock_init(&pindesc->lock); + + /* Set owner */ + pindesc->pctldev = pctldev; + + /* Copy optional basic pin info */ + if (name) + strlcpy(pindesc->name, name, sizeof(pindesc->name)); + + spin_lock(&pctldev->pin_desc_tree_lock); + radix_tree_insert(&pctldev->pin_desc_tree, number, pindesc); + spin_unlock(&pctldev->pin_desc_tree_lock); + pr_debug("registered pin %d (%s) on %s\n", + number, name ? name : "(unnamed)", pctldev->desc->name); + return 0; +} + +static int pinctrl_register_pins(struct pinctrl_dev *pctldev, + struct pinctrl_pin_desc const *pins, + unsigned num_descs) +{ + unsigned i; + int ret = 0; + + for (i = 0; i < num_descs; i++) { + ret = pinctrl_register_one_pin(pctldev, + pins[i].number, pins[i].name); + if (ret) + return ret; + } + + return 0; +} + +/** + * pinctrl_match_gpio_range() - check if a certain GPIO pin is in range + * @pctldev: pin controller device to check + * @gpio: gpio pin to check taken from the global GPIO pin space + * + * Tries to match a GPIO pin number to the ranges handled by a certain pin + * controller, return the range or NULL + */ +static struct pinctrl_gpio_range * +pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio) +{ + struct pinctrl_gpio_range *range = NULL; + + /* Loop over the ranges */ + mutex_lock(&pctldev->gpio_ranges_lock); + list_for_each_entry(range, &pctldev->gpio_ranges, node) { + /* Check if we're in the valid range */ + if (gpio >= range->base && + gpio < range->base + range->npins) { + mutex_unlock(&pctldev->gpio_ranges_lock); + return range; + } + } + mutex_unlock(&pctldev->gpio_ranges_lock); + + return NULL; +} + +/** + * pinctrl_get_device_gpio_range() - find device for GPIO range + * @gpio: the pin to locate the pin controller for + * @outdev: the pin control device if found + * @outrange: the GPIO range if found + * + * Find the pin controller handling a certain GPIO pin from the pinspace of + * the GPIO subsystem, return the device and the matching GPIO range. Returns + * negative if the GPIO range could not be found in any device. + */ +int pinctrl_get_device_gpio_range(unsigned gpio, + struct pinctrl_dev **outdev, + struct pinctrl_gpio_range **outrange) +{ + struct pinctrl_dev *pctldev = NULL; + + /* Loop over the pin controllers */ + mutex_lock(&pinctrldev_list_mutex); + list_for_each_entry(pctldev, &pinctrldev_list, node) { + struct pinctrl_gpio_range *range; + + range = pinctrl_match_gpio_range(pctldev, gpio); + if (range != NULL) { + *outdev = pctldev; + *outrange = range; + mutex_unlock(&pinctrldev_list_mutex); + return 0; + } + } + mutex_unlock(&pinctrldev_list_mutex); + + return -EINVAL; +} + +/** + * pinctrl_add_gpio_range() - register a GPIO range for a controller + * @pctldev: pin controller device to add the range to + * @range: the GPIO range to add + * + * This adds a range of GPIOs to be handled by a certain pin controller. Call + * this to register handled ranges after registering your pin controller. + */ +void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range) +{ + mutex_lock(&pctldev->gpio_ranges_lock); + list_add(&range->node, &pctldev->gpio_ranges); + mutex_unlock(&pctldev->gpio_ranges_lock); +} + +/** + * pinctrl_remove_gpio_range() - remove a range of GPIOs fro a pin controller + * @pctldev: pin controller device to remove the range from + * @range: the GPIO range to remove + */ +void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range) +{ + mutex_lock(&pctldev->gpio_ranges_lock); + list_del(&range->node); + mutex_unlock(&pctldev->gpio_ranges_lock); +} + +#ifdef CONFIG_DEBUG_FS + +static int pinctrl_pins_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + const struct pinctrl_ops *ops = pctldev->desc->pctlops; + unsigned pin; + + seq_printf(s, "registered pins: %d\n", pctldev->desc->npins); + seq_printf(s, "max pin number: %d\n", pctldev->desc->maxpin); + + /* The highest pin number need to be included in the loop, thus <= */ + for (pin = 0; pin <= pctldev->desc->maxpin; pin++) { + struct pin_desc *desc; + + desc = pin_desc_get(pctldev, pin); + /* Pin space may be sparse */ + if (desc == NULL) + continue; + + seq_printf(s, "pin %d (%s) ", pin, + desc->name ? desc->name : "unnamed"); + + /* Driver-specific info per pin */ + if (ops->pin_dbg_show) + ops->pin_dbg_show(pctldev, s, pin); + + seq_puts(s, "\n"); + } + + return 0; +} + +static int pinctrl_groups_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + const struct pinctrl_ops *ops = pctldev->desc->pctlops; + unsigned selector = 0; + + /* No grouping */ + if (!ops) + return 0; + + seq_puts(s, "registered pin groups:\n"); + while (ops->list_groups(pctldev, selector) >= 0) { + unsigned *pins; + unsigned num_pins; + const char *gname = ops->get_group_name(pctldev, selector); + int ret; + int i; + + ret = ops->get_group_pins(pctldev, selector, + &pins, &num_pins); + if (ret) + seq_printf(s, "%s [ERROR GETTING PINS]\n", + gname); + else { + seq_printf(s, "group: %s, pins = [ ", gname); + for (i = 0; i < num_pins; i++) + seq_printf(s, "%d ", pins[i]); + seq_puts(s, "]\n"); + } + selector++; + } + + + return 0; +} + +static int pinctrl_gpioranges_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + struct pinctrl_gpio_range *range = NULL; + + seq_puts(s, "GPIO ranges handled:\n"); + + /* Loop over the ranges */ + mutex_lock(&pctldev->gpio_ranges_lock); + list_for_each_entry(range, &pctldev->gpio_ranges, node) { + seq_printf(s, "%u: %s [%u - %u]\n", range->id, range->name, + range->base, (range->base + range->npins - 1)); + } + mutex_unlock(&pctldev->gpio_ranges_lock); + + return 0; +} + +static int pinctrl_devices_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev; + + seq_puts(s, "name [pinmux]\n"); + mutex_lock(&pinctrldev_list_mutex); + list_for_each_entry(pctldev, &pinctrldev_list, node) { + seq_printf(s, "%s ", pctldev->desc->name); + if (pctldev->desc->pmxops) + seq_puts(s, "yes"); + else + seq_puts(s, "no"); + seq_puts(s, "\n"); + } + mutex_unlock(&pinctrldev_list_mutex); + + return 0; +} + +static int pinctrl_pins_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinctrl_pins_show, inode->i_private); +} + +static int pinctrl_groups_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinctrl_groups_show, inode->i_private); +} + +static int pinctrl_gpioranges_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinctrl_gpioranges_show, inode->i_private); +} + +static int pinctrl_devices_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinctrl_devices_show, NULL); +} + +static const struct file_operations pinctrl_pins_ops = { + .open = pinctrl_pins_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinctrl_groups_ops = { + .open = pinctrl_groups_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinctrl_gpioranges_ops = { + .open = pinctrl_gpioranges_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinctrl_devices_ops = { + .open = pinctrl_devices_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static struct dentry *debugfs_root; + +static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev) +{ + static struct dentry *device_root; + + device_root = debugfs_create_dir(dev_name(&pctldev->dev), + debugfs_root); + if (IS_ERR(device_root) || !device_root) { + pr_warn("failed to create debugfs directory for %s\n", + dev_name(&pctldev->dev)); + return; + } + debugfs_create_file("pins", S_IFREG | S_IRUGO, + device_root, pctldev, &pinctrl_pins_ops); + debugfs_create_file("pingroups", S_IFREG | S_IRUGO, + device_root, pctldev, &pinctrl_groups_ops); + debugfs_create_file("gpio-ranges", S_IFREG | S_IRUGO, + device_root, pctldev, &pinctrl_gpioranges_ops); + pinmux_init_device_debugfs(device_root, pctldev); +} + +static void pinctrl_init_debugfs(void) +{ + debugfs_root = debugfs_create_dir("pinctrl", NULL); + if (IS_ERR(debugfs_root) || !debugfs_root) { + pr_warn("failed to create debugfs directory\n"); + debugfs_root = NULL; + return; + } + + debugfs_create_file("pinctrl-devices", S_IFREG | S_IRUGO, + debugfs_root, NULL, &pinctrl_devices_ops); + pinmux_init_debugfs(debugfs_root); +} + +#else /* CONFIG_DEBUG_FS */ + +static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev) +{ +} + +static void pinctrl_init_debugfs(void) +{ +} + +#endif + +/** + * pinctrl_register() - register a pin controller device + * @pctldesc: descriptor for this pin controller + * @dev: parent device for this pin controller + * @driver_data: private pin controller data for this pin controller + */ +struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc, + struct device *dev, void *driver_data) +{ + static atomic_t pinmux_no = ATOMIC_INIT(0); + struct pinctrl_dev *pctldev; + int ret; + + if (pctldesc == NULL) + return NULL; + if (pctldesc->name == NULL) + return NULL; + + /* If we're implementing pinmuxing, check the ops for sanity */ + if (pctldesc->pmxops) { + ret = pinmux_check_ops(pctldesc->pmxops); + if (ret) { + pr_err("%s pinmux ops lacks necessary functions\n", + pctldesc->name); + return NULL; + } + } + + pctldev = kzalloc(sizeof(struct pinctrl_dev), GFP_KERNEL); + if (pctldev == NULL) + return NULL; + + /* Initialize pin control device struct */ + pctldev->owner = pctldesc->owner; + pctldev->desc = pctldesc; + pctldev->driver_data = driver_data; + INIT_RADIX_TREE(&pctldev->pin_desc_tree, GFP_KERNEL); + spin_lock_init(&pctldev->pin_desc_tree_lock); + INIT_LIST_HEAD(&pctldev->gpio_ranges); + mutex_init(&pctldev->gpio_ranges_lock); + + /* Register device */ + pctldev->dev.parent = dev; + dev_set_name(&pctldev->dev, "pinctrl.%d", + atomic_inc_return(&pinmux_no) - 1); + pctldev->dev.release = pinctrl_dev_release; + ret = device_register(&pctldev->dev); + if (ret != 0) { + pr_err("error in device registration\n"); + goto out_reg_dev_err; + } + dev_set_drvdata(&pctldev->dev, pctldev); + + /* Register all the pins */ + pr_debug("try to register %d pins on %s...\n", + pctldesc->npins, pctldesc->name); + ret = pinctrl_register_pins(pctldev, pctldesc->pins, pctldesc->npins); + if (ret) { + pr_err("error during pin registration\n"); + pinctrl_free_pindescs(pctldev, pctldesc->pins, + pctldesc->npins); + goto out_reg_pins_err; + } + + pinctrl_init_device_debugfs(pctldev); + mutex_lock(&pinctrldev_list_mutex); + list_add(&pctldev->node, &pinctrldev_list); + mutex_unlock(&pinctrldev_list_mutex); + pinmux_hog_maps(pctldev); + return pctldev; + +out_reg_pins_err: + device_del(&pctldev->dev); +out_reg_dev_err: + put_device(&pctldev->dev); + return NULL; +} +EXPORT_SYMBOL_GPL(pinctrl_register); + +/** + * pinctrl_unregister() - unregister pinmux + * @pctldev: pin controller to unregister + * + * Called by pinmux drivers to unregister a pinmux. + */ +void pinctrl_unregister(struct pinctrl_dev *pctldev) +{ + if (pctldev == NULL) + return; + + pinmux_unhog_maps(pctldev); + /* TODO: check that no pinmuxes are still active? */ + mutex_lock(&pinctrldev_list_mutex); + list_del(&pctldev->node); + mutex_unlock(&pinctrldev_list_mutex); + /* Destroy descriptor tree */ + pinctrl_free_pindescs(pctldev, pctldev->desc->pins, + pctldev->desc->npins); + device_unregister(&pctldev->dev); +} +EXPORT_SYMBOL_GPL(pinctrl_unregister); + +static int __init pinctrl_init(void) +{ + pr_info("initialized pinctrl subsystem\n"); + pinctrl_init_debugfs(); + return 0; +} + +/* init early since many drivers really need to initialized pinmux early */ +core_initcall(pinctrl_init); diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h new file mode 100644 index 0000000..17e0777 --- /dev/null +++ b/drivers/pinctrl/core.h @@ -0,0 +1,72 @@ +/* + * Core private header for the pin control subsystem + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ + +/** + * struct pinctrl_dev - pin control class device + * @node: node to include this pin controller in the global pin controller list + * @desc: the pin controller descriptor supplied when initializing this pin + * controller + * @pin_desc_tree: each pin descriptor for this pin controller is stored in + * this radix tree + * @pin_desc_tree_lock: lock for the descriptor tree + * @gpio_ranges: a list of GPIO ranges that is handled by this pin controller, + * ranges are added to this list at runtime + * @gpio_ranges_lock: lock for the GPIO ranges list + * @dev: the device entry for this pin controller + * @owner: module providing the pin controller, used for refcounting + * @driver_data: driver data for drivers registering to the pin controller + * subsystem + * @pinmux_hogs_lock: lock for the pinmux hog list + * @pinmux_hogs: list of pinmux maps hogged by this device + */ +struct pinctrl_dev { + struct list_head node; + struct pinctrl_desc *desc; + struct radix_tree_root pin_desc_tree; + spinlock_t pin_desc_tree_lock; + struct list_head gpio_ranges; + struct mutex gpio_ranges_lock; + struct device dev; + struct module *owner; + void *driver_data; +#ifdef CONFIG_PINMUX + struct mutex pinmux_hogs_lock; + struct list_head pinmux_hogs; +#endif +}; + +/** + * struct pin_desc - pin descriptor for each physical pin in the arch + * @pctldev: corresponding pin control device + * @name: a name for the pin, e.g. the name of the pin/pad/finger on a + * datasheet or such + * @lock: a lock to protect the descriptor structure + * @mux_requested: whether the pin is already requested by pinmux or not + * @mux_function: a named muxing function for the pin that will be passed to + * subdrivers and shown in debugfs etc + */ +struct pin_desc { + struct pinctrl_dev *pctldev; + char name[16]; + spinlock_t lock; + /* These fields only added when supporting pinmux drivers */ +#ifdef CONFIG_PINMUX + bool mux_requested; + char mux_function[16]; +#endif +}; + +struct pinctrl_dev *get_pinctrl_dev_from_dev(struct device *dev, + const char *dev_name); +struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, int pin); +int pinctrl_get_device_gpio_range(unsigned gpio, + struct pinctrl_dev **outdev, + struct pinctrl_gpio_range **outrange); diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c new file mode 100644 index 0000000..6544d98 --- /dev/null +++ b/drivers/pinctrl/pinmux.c @@ -0,0 +1,1180 @@ +/* + * Core driver for the pin muxing portions of the pin control subsystem + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * Based on bits of regulator core, gpio core and clk core + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ +#define pr_fmt(fmt) "pinmux core: " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/radix-tree.h> +#include <linux/err.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/spinlock.h> +#include <linux/sysfs.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <linux/pinctrl/machine.h> +#include <linux/pinctrl/pinmux.h> +#include "core.h" + +/* List of pinmuxes */ +static DEFINE_MUTEX(pinmux_list_mutex); +static LIST_HEAD(pinmux_list); + +/* List of pinmux hogs */ +static DEFINE_MUTEX(pinmux_hoglist_mutex); +static LIST_HEAD(pinmux_hoglist); + +/* Global pinmux maps, we allow one set only */ +static struct pinmux_map const *pinmux_maps; +static unsigned pinmux_maps_num; + +/** + * struct pinmux_group - group list item for pinmux groups + * @node: pinmux group list node + * @group_selector: the group selector for this group + */ +struct pinmux_group { + struct list_head node; + unsigned group_selector; +}; + +/** + * struct pinmux - per-device pinmux state holder + * @node: global list node + * @dev: the device using this pinmux + * @usecount: the number of active users of this mux setting, used to keep + * track of nested use cases + * @pins: an array of discrete physical pins used in this mapping, taken + * from the global pin enumeration space (copied from pinmux map) + * @num_pins: the number of pins in this mapping array, i.e. the number of + * elements in .pins so we can iterate over that array (copied from + * pinmux map) + * @pctldev: pin control device handling this pinmux + * @func_selector: the function selector for the pinmux device handling + * this pinmux + * @groups: the group selectors for the pinmux device and + * selector combination handling this pinmux, this is a list that + * will be traversed on all pinmux operations such as + * get/put/enable/disable + * @mutex: a lock for the pinmux state holder + */ +struct pinmux { + struct list_head node; + struct device *dev; + unsigned usecount; + struct pinctrl_dev *pctldev; + unsigned func_selector; + struct list_head groups; + struct mutex mutex; +}; + +/** + * struct pinmux_hog - a list item to stash mux hogs + * @node: pinmux hog list node + * @map: map entry responsible for this hogging + * @pmx: the pinmux hogged by this item + */ +struct pinmux_hog { + struct list_head node; + struct pinmux_map const *map; + struct pinmux *pmx; +}; + +/** + * pin_request() - request a single pin to be muxed in, typically for GPIO + * @pin: the pin number in the global pin space + * @function: a functional name to give to this pin, passed to the driver + * so it knows what function to mux in, e.g. the string "gpioNN" + * means that you want to mux in the pin for use as GPIO number NN + * @gpio: if this request concerns a single GPIO pin + * @gpio_range: the range matching the GPIO pin if this is a request for a + * single GPIO pin + */ +static int pin_request(struct pinctrl_dev *pctldev, + int pin, const char *function, bool gpio, + struct pinctrl_gpio_range *gpio_range) +{ + struct pin_desc *desc; + const struct pinmux_ops *ops = pctldev->desc->pmxops; + int status = -EINVAL; + + dev_dbg(&pctldev->dev, "request pin %d for %s\n", pin, function); + + if (!pin_is_valid(pctldev, pin)) { + dev_err(&pctldev->dev, "pin is invalid\n"); + return -EINVAL; + } + + if (!function) { + dev_err(&pctldev->dev, "no function name given\n"); + return -EINVAL; + } + + desc = pin_desc_get(pctldev, pin); + if (desc == NULL) { + dev_err(&pctldev->dev, + "pin is not registered so it cannot be requested\n"); + goto out; + } + + spin_lock(&desc->lock); + if (desc->mux_requested) { + spin_unlock(&desc->lock); + dev_err(&pctldev->dev, + "pin already requested\n"); + goto out; + } + desc->mux_requested = true; + strncpy(desc->mux_function, function, sizeof(desc->mux_function)); + spin_unlock(&desc->lock); + + /* Let each pin increase references to this module */ + if (!try_module_get(pctldev->owner)) { + dev_err(&pctldev->dev, + "could not increase module refcount for pin %d\n", + pin); + status = -EINVAL; + goto out_free_pin; + } + + /* + * If there is no kind of request function for the pin we just assume + * we got it by default and proceed. + */ + if (gpio && ops->gpio_request_enable) + /* This requests and enables a single GPIO pin */ + status = ops->gpio_request_enable(pctldev, gpio_range, pin); + else if (ops->request) + status = ops->request(pctldev, pin); + else + status = 0; + + if (status) + dev_err(&pctldev->dev, "->request on device %s failed " + "for pin %d\n", + pctldev->desc->name, pin); +out_free_pin: + if (status) { + spin_lock(&desc->lock); + desc->mux_requested = false; + desc->mux_function[0] = '\0'; + spin_unlock(&desc->lock); + } +out: + if (status) + dev_err(&pctldev->dev, "pin-%d (%s) status %d\n", + pin, function ? : "?", status); + + return status; +} + +/** + * pin_free() - release a single muxed in pin so something else can be muxed + * @pctldev: pin controller device handling this pin + * @pin: the pin to free + */ +static void pin_free(struct pinctrl_dev *pctldev, int pin) +{ + const struct pinmux_ops *ops = pctldev->desc->pmxops; + struct pin_desc *desc; + + desc = pin_desc_get(pctldev, pin); + if (desc == NULL) { + dev_err(&pctldev->dev, + "pin is not registered so it cannot be freed\n"); + return; + } + + if (ops->free) + ops->free(pctldev, pin); + + spin_lock(&desc->lock); + desc->mux_requested = false; + desc->mux_function[0] = '\0'; + spin_unlock(&desc->lock); + module_put(pctldev->owner); +} + +/** + * pinmux_request_gpio() - request a single pin to be muxed in as GPIO + * @gpio: the GPIO pin number from the GPIO subsystem number space + */ +int pinmux_request_gpio(unsigned gpio) +{ + char gpiostr[16]; + struct pinctrl_dev *pctldev; + struct pinctrl_gpio_range *range; + int ret; + int pin; + + ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range); + if (ret) + return -EINVAL; + + /* Convert to the pin controllers number space */ + pin = gpio - range->base; + + /* Conjure some name stating what chip and pin this is taken by */ + snprintf(gpiostr, 15, "%s:%d", range->name, gpio); + + return pin_request(pctldev, pin, gpiostr, true, range); +} +EXPORT_SYMBOL_GPL(pinmux_request_gpio); + +/** + * pinmux_free_gpio() - free a single pin, currently used as GPIO + * @gpio: the GPIO pin number from the GPIO subsystem number space + */ +void pinmux_free_gpio(unsigned gpio) +{ + struct pinctrl_dev *pctldev; + struct pinctrl_gpio_range *range; + int ret; + int pin; + + ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range); + if (ret) + return; + + /* Convert to the pin controllers number space */ + pin = gpio - range->base; + + pin_free(pctldev, pin); +} +EXPORT_SYMBOL_GPL(pinmux_free_gpio); + +/** + * pinmux_register_mappings() - register a set of pinmux mappings + * @maps: the pinmux mappings table to register + * @num_maps: the number of maps in the mapping table + * + * Only call this once during initialization of your machine, the function is + * tagged as __init and won't be callable after init has completed. The map + * passed into this function will be owned by the pinmux core and cannot be + * free:d. + */ +int __init pinmux_register_mappings(struct pinmux_map const *maps, + unsigned num_maps) +{ + int i; + + if (pinmux_maps != NULL) { + pr_err("pinmux mappings already registered, you can only " + "register one set of maps\n"); + return -EINVAL; + } + + pr_debug("add %d pinmux maps\n", num_maps); + for (i = 0; i < num_maps; i++) { + /* Sanity check the mapping */ + if (!maps[i].name) { + pr_err("failed to register map %d: " + "no map name given\n", i); + return -EINVAL; + } + if (!maps[i].ctrl_dev && !maps[i].ctrl_dev_name) { + pr_err("failed to register map %s (%d): " + "no pin control device given\n", + maps[i].name, i); + return -EINVAL; + } + if (!maps[i].function) { + pr_err("failed to register map %s (%d): " + "no function ID given\n", maps[i].name, i); + return -EINVAL; + } + + if (!maps[i].dev && !maps[i].dev_name) + pr_debug("add system map %s function %s with no device\n", + maps[i].name, + maps[i].function); + else + pr_debug("register map %s, function %s\n", + maps[i].name, + maps[i].function); + } + + pinmux_maps = maps; + pinmux_maps_num = num_maps; + + return 0; +} + +/** + * acquire_pins() - acquire all the pins for a certain funcion on a pinmux + * @pctldev: the device to take the pins on + * @func_selector: the function selector to acquire the pins for + * @group_selector: the group selector containing the pins to acquire + */ +static int acquire_pins(struct pinctrl_dev *pctldev, + unsigned func_selector, + unsigned group_selector) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + const struct pinmux_ops *pmxops = pctldev->desc->pmxops; + const char *func = pmxops->get_function_name(pctldev, + func_selector); + unsigned *pins; + unsigned num_pins; + int ret; + int i; + + ret = pctlops->get_group_pins(pctldev, group_selector, + &pins, &num_pins); + if (ret) + return ret; + + dev_dbg(&pctldev->dev, "requesting the %u pins from group %u\n", + num_pins, group_selector); + + /* Try to allocate all pins in this group, one by one */ + for (i = 0; i < num_pins; i++) { + ret = pin_request(pctldev, pins[i], func, false, NULL); + if (ret) { + dev_err(&pctldev->dev, + "could not get pin %d for function %s " + "on device %s - conflicting mux mappings?\n", + pins[i], func ? : "(undefined)", + pinctrl_dev_get_name(pctldev)); + /* On error release all taken pins */ + i--; /* this pin just failed */ + for (; i >= 0; i--) + pin_free(pctldev, pins[i]); + return -ENODEV; + } + } + return 0; +} + +/** + * release_pins() - release pins taken by earlier acquirement + * @pctldev: the device to free the pinx on + * @group_selector: the group selector containing the pins to free + */ +static void release_pins(struct pinctrl_dev *pctldev, + unsigned group_selector) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + unsigned *pins; + unsigned num_pins; + int ret; + int i; + + ret = pctlops->get_group_pins(pctldev, group_selector, + &pins, &num_pins); + if (ret) { + dev_err(&pctldev->dev, "could not get pins to release for " + "group selector %d\n", + group_selector); + return; + } + for (i = 0; i < num_pins; i++) + pin_free(pctldev, pins[i]); +} + +/** + * pinmux_get_group_selector() - returns the group selector for a group + * @pctldev: the pin controller handling the group + * @pin_group: the pin group to look up + */ +static int pinmux_get_group_selector(struct pinctrl_dev *pctldev, + const char *pin_group) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + unsigned group_selector = 0; + + while (pctlops->list_groups(pctldev, group_selector) >= 0) { + const char *gname = pctlops->get_group_name(pctldev, + group_selector); + if (!strcmp(gname, pin_group)) { + dev_dbg(&pctldev->dev, + "found group selector %u for %s\n", + group_selector, + pin_group); + return group_selector; + } + + group_selector++; + } + + dev_err(&pctldev->dev, "does not have pin group %s\n", + pin_group); + + return -EINVAL; +} + +/** + * pinmux_check_pin_group() - check function and pin group combo + * @pctldev: device to check the pin group vs function for + * @func_selector: the function selector to check the pin group for, we have + * already looked this up in the calling function + * @pin_group: the pin group to match to the function + * + * This function will check that the pinmux driver can supply the + * selected pin group for a certain function, returns the group selector if + * the group and function selector will work fine together, else returns + * negative + */ +static int pinmux_check_pin_group(struct pinctrl_dev *pctldev, + unsigned func_selector, + const char *pin_group) +{ + const struct pinmux_ops *pmxops = pctldev->desc->pmxops; + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + int ret; + + /* + * If the driver does not support different pin groups for the + * functions, we only support group 0, and assume this exists. + */ + if (!pctlops || !pctlops->list_groups) + return 0; + + /* + * Passing NULL (no specific group) will select the first and + * hopefully only group of pins available for this function. + */ + if (!pin_group) { + char const * const *groups; + unsigned num_groups; + + ret = pmxops->get_function_groups(pctldev, func_selector, + &groups, &num_groups); + if (ret) + return ret; + if (num_groups < 1) + return -EINVAL; + ret = pinmux_get_group_selector(pctldev, groups[0]); + if (ret < 0) { + dev_err(&pctldev->dev, + "function %s wants group %s but the pin " + "controller does not seem to have that group\n", + pmxops->get_function_name(pctldev, func_selector), + groups[0]); + return ret; + } + + if (num_groups > 1) + dev_dbg(&pctldev->dev, + "function %s support more than one group, " + "default-selecting first group %s (%d)\n", + pmxops->get_function_name(pctldev, func_selector), + groups[0], + ret); + + return ret; + } + + dev_dbg(&pctldev->dev, + "check if we have pin group %s on controller %s\n", + pin_group, pinctrl_dev_get_name(pctldev)); + + ret = pinmux_get_group_selector(pctldev, pin_group); + if (ret < 0) { + dev_dbg(&pctldev->dev, + "%s does not support pin group %s with function %s\n", + pinctrl_dev_get_name(pctldev), + pin_group, + pmxops->get_function_name(pctldev, func_selector)); + } + return ret; +} + +/** + * pinmux_search_function() - check pin control driver for a certain function + * @pctldev: device to check for function and position + * @map: function map containing the function and position to look for + * @func_selector: returns the applicable function selector if found + * @group_selector: returns the applicable group selector if found + * + * This will search the pinmux driver for an applicable + * function with a specific pin group, returns 0 if these can be mapped + * negative otherwise + */ +static int pinmux_search_function(struct pinctrl_dev *pctldev, + struct pinmux_map const *map, + unsigned *func_selector, + unsigned *group_selector) +{ + const struct pinmux_ops *ops = pctldev->desc->pmxops; + unsigned selector = 0; + + /* See if this pctldev has this function */ + while (ops->list_functions(pctldev, selector) >= 0) { + const char *fname = ops->get_function_name(pctldev, + selector); + int ret; + + if (!strcmp(map->function, fname)) { + /* Found the function, check pin group */ + ret = pinmux_check_pin_group(pctldev, selector, + map->group); + if (ret < 0) + return ret; + + /* This function and group selector can be used */ + *func_selector = selector; + *group_selector = ret; + return 0; + + } + selector++; + } + + pr_err("%s does not support function %s\n", + pinctrl_dev_get_name(pctldev), map->function); + return -EINVAL; +} + +/** + * pinmux_enable_muxmap() - enable a map entry for a certain pinmux + */ +static int pinmux_enable_muxmap(struct pinctrl_dev *pctldev, + struct pinmux *pmx, + struct device *dev, + const char *devname, + struct pinmux_map const *map) +{ + unsigned func_selector; + unsigned group_selector; + struct pinmux_group *grp; + int ret; + + /* + * Note that we're not locking the pinmux mutex here, because + * this is only called at pinmux initialization time when it + * has not been added to any list and thus is not reachable + * by anyone else. + */ + + if (pmx->pctldev && pmx->pctldev != pctldev) { + dev_err(&pctldev->dev, + "different pin control devices given for device %s, " + "function %s\n", + devname, + map->function); + return -EINVAL; + } + pmx->dev = dev; + pmx->pctldev = pctldev; + + /* Now go into the driver and try to match a function and group */ + ret = pinmux_search_function(pctldev, map, &func_selector, + &group_selector); + if (ret < 0) + return ret; + + /* + * If the function selector is already set, it needs to be identical, + * we support several groups with one function but not several + * functions with one or several groups in the same pinmux. + */ + if (pmx->func_selector != UINT_MAX && + pmx->func_selector != func_selector) { + dev_err(&pctldev->dev, + "dual function defines in the map for device %s\n", + devname); + return -EINVAL; + } + pmx->func_selector = func_selector; + + /* Now add this group selector, we may have many of them */ + grp = kmalloc(sizeof(struct pinmux_group), GFP_KERNEL); + if (!grp) + return -ENOMEM; + grp->group_selector = group_selector; + ret = acquire_pins(pctldev, func_selector, group_selector); + if (ret) { + kfree(grp); + return ret; + } + list_add(&grp->node, &pmx->groups); + + return 0; +} + +static void pinmux_free_groups(struct pinmux *pmx) +{ + struct list_head *node, *tmp; + + list_for_each_safe(node, tmp, &pmx->groups) { + struct pinmux_group *grp = + list_entry(node, struct pinmux_group, node); + /* Release all pins taken by this group */ + release_pins(pmx->pctldev, grp->group_selector); + list_del(node); + kfree(grp); + } +} + +/** + * pinmux_get() - retrieves the pinmux for a certain device + * @dev: the device to get the pinmux for + * @name: an optional specific mux mapping name or NULL, the name is only + * needed if you want to have more than one mapping per device, or if you + * need an anonymous pinmux (not tied to any specific device) + */ +struct pinmux *pinmux_get(struct device *dev, const char *name) +{ + + struct pinmux_map const *map = NULL; + struct pinctrl_dev *pctldev = NULL; + const char *devname = NULL; + struct pinmux *pmx; + bool found_map; + unsigned num_maps = 0; + int ret = -ENODEV; + int i; + + /* We must have dev or ID or both */ + if (!dev && !name) + return ERR_PTR(-EINVAL); + + if (dev) + devname = dev_name(dev); + + pr_debug("get mux %s for device %s\n", name, + devname ? devname : "(none)"); + + /* + * create the state cookie holder struct pinmux for each + * mapping, this is what consumers will get when requesting + * a pinmux handle with pinmux_get() + */ + pmx = kzalloc(sizeof(struct pinmux), GFP_KERNEL); + if (pmx == NULL) + return ERR_PTR(-ENOMEM); + mutex_init(&pmx->mutex); + pmx->func_selector = UINT_MAX; + INIT_LIST_HEAD(&pmx->groups); + + /* Iterate over the pinmux maps to locate the right ones */ + for (i = 0; i < pinmux_maps_num; i++) { + map = &pinmux_maps[i]; + found_map = false; + + /* + * First, try to find the pctldev given in the map + */ + pctldev = get_pinctrl_dev_from_dev(map->ctrl_dev, + map->ctrl_dev_name); + if (!pctldev) { + const char *devname = NULL; + + if (map->ctrl_dev) + devname = dev_name(map->ctrl_dev); + else if (map->ctrl_dev_name) + devname = map->ctrl_dev_name; + + pr_warning("could not find a pinctrl device for pinmux " + "function %s, fishy, they shall all have one\n", + map->function); + pr_warning("given pinctrl device name: %s", + devname ? devname : "UNDEFINED"); + + /* Continue to check the other mappings anyway... */ + continue; + } + + pr_debug("in map, found pctldev %s to handle function %s", + dev_name(&pctldev->dev), map->function); + + + /* + * If we're looking for a specific named map, this must match, + * else we loop and look for the next. + */ + if (name != NULL) { + if (map->name == NULL) + continue; + if (strcmp(map->name, name)) + continue; + } + + /* + * This is for the case where no device name is given, we + * already know that the function name matches from above + * code. + */ + if (!map->dev_name && (name != NULL)) + found_map = true; + + /* If the mapping has a device set up it must match */ + if (map->dev_name && + (!devname || !strcmp(map->dev_name, devname))) + /* MATCH! */ + found_map = true; + + /* If this map is applicable, then apply it */ + if (found_map) { + ret = pinmux_enable_muxmap(pctldev, pmx, dev, + devname, map); + if (ret) { + pinmux_free_groups(pmx); + kfree(pmx); + return ERR_PTR(ret); + } + num_maps++; + } + } + + + /* We should have atleast one map, right */ + if (!num_maps) { + pr_err("could not find any mux maps for device %s, ID %s\n", + devname ? devname : "(anonymous)", + name ? name : "(undefined)"); + kfree(pmx); + return ERR_PTR(-EINVAL); + } + + pr_debug("found %u mux maps for device %s, UD %s\n", + num_maps, + devname ? devname : "(anonymous)", + name ? name : "(undefined)"); + + /* Add the pinmux to the global list */ + mutex_lock(&pinmux_list_mutex); + list_add(&pmx->node, &pinmux_list); + mutex_unlock(&pinmux_list_mutex); + + return pmx; +} +EXPORT_SYMBOL_GPL(pinmux_get); + +/** + * pinmux_put() - release a previously claimed pinmux + * @pmx: a pinmux previously claimed by pinmux_get() + */ +void pinmux_put(struct pinmux *pmx) +{ + if (pmx == NULL) + return; + + mutex_lock(&pmx->mutex); + if (pmx->usecount) + pr_warn("releasing pinmux with active users!\n"); + /* Free the groups and all acquired pins */ + pinmux_free_groups(pmx); + mutex_unlock(&pmx->mutex); + + /* Remove from list */ + mutex_lock(&pinmux_list_mutex); + list_del(&pmx->node); + mutex_unlock(&pinmux_list_mutex); + + kfree(pmx); +} +EXPORT_SYMBOL_GPL(pinmux_put); + +/** + * pinmux_enable() - enable a certain pinmux setting + * @pmx: the pinmux to enable, previously claimed by pinmux_get() + */ +int pinmux_enable(struct pinmux *pmx) +{ + int ret = 0; + + if (pmx == NULL) + return -EINVAL; + mutex_lock(&pmx->mutex); + if (pmx->usecount++ == 0) { + struct pinctrl_dev *pctldev = pmx->pctldev; + const struct pinmux_ops *ops = pctldev->desc->pmxops; + struct pinmux_group *grp; + + list_for_each_entry(grp, &pmx->groups, node) { + ret = ops->enable(pctldev, pmx->func_selector, + grp->group_selector); + if (ret) { + /* + * TODO: call disable() on all groups we called + * enable() on to this point? + */ + pmx->usecount--; + break; + } + } + } + mutex_unlock(&pmx->mutex); + return ret; +} +EXPORT_SYMBOL_GPL(pinmux_enable); + +/** + * pinmux_disable() - disable a certain pinmux setting + * @pmx: the pinmux to disable, previously claimed by pinmux_get() + */ +void pinmux_disable(struct pinmux *pmx) +{ + if (pmx == NULL) + return; + + mutex_lock(&pmx->mutex); + if (--pmx->usecount == 0) { + struct pinctrl_dev *pctldev = pmx->pctldev; + const struct pinmux_ops *ops = pctldev->desc->pmxops; + struct pinmux_group *grp; + + list_for_each_entry(grp, &pmx->groups, node) { + ops->disable(pctldev, pmx->func_selector, + grp->group_selector); + } + } + mutex_unlock(&pmx->mutex); +} +EXPORT_SYMBOL_GPL(pinmux_disable); + +int pinmux_check_ops(const struct pinmux_ops *ops) +{ + /* Check that we implement required operations */ + if (!ops->list_functions || + !ops->get_function_name || + !ops->get_function_groups || + !ops->enable || + !ops->disable) + return -EINVAL; + + return 0; +} + +/* Hog a single map entry and add to the hoglist */ +static int pinmux_hog_map(struct pinctrl_dev *pctldev, + struct pinmux_map const *map) +{ + struct pinmux_hog *hog; + struct pinmux *pmx; + int ret; + + if (map->dev || map->dev_name) { + /* + * TODO: the day we have device tree support, we can + * traverse the device tree and hog to specific device nodes + * without any problems, so then we can hog pinmuxes for + * all devices that just want a static pin mux at this point. + */ + dev_err(&pctldev->dev, "map %s wants to hog a non-system " + "pinmux, this is not going to work\n", map->name); + return -EINVAL; + } + + hog = kzalloc(sizeof(struct pinmux_hog), GFP_KERNEL); + if (!hog) + return -ENOMEM; + + pmx = pinmux_get(NULL, map->name); + if (IS_ERR(pmx)) { + kfree(hog); + dev_err(&pctldev->dev, + "could not get the %s pinmux mapping for hogging\n", + map->name); + return PTR_ERR(pmx); + } + + ret = pinmux_enable(pmx); + if (ret) { + pinmux_put(pmx); + kfree(hog); + dev_err(&pctldev->dev, + "could not enable the %s pinmux mapping for hogging\n", + map->name); + return ret; + } + + hog->map = map; + hog->pmx = pmx; + + dev_info(&pctldev->dev, "hogged map %s, function %s\n", map->name, + map->function); + mutex_lock(&pctldev->pinmux_hogs_lock); + list_add(&hog->node, &pctldev->pinmux_hogs); + mutex_unlock(&pctldev->pinmux_hogs_lock); + + return 0; +} + +/** + * pinmux_hog_maps() - hog specific map entries on controller device + * @pctldev: the pin control device to hog entries on + * + * When the pin controllers are registered, there may be some specific pinmux + * map entries that need to be hogged, i.e. get+enabled until the system shuts + * down. + */ +int pinmux_hog_maps(struct pinctrl_dev *pctldev) +{ + struct device *dev = &pctldev->dev; + const char *devname = dev_name(dev); + int ret; + int i; + + INIT_LIST_HEAD(&pctldev->pinmux_hogs); + mutex_init(&pctldev->pinmux_hogs_lock); + + for (i = 0; i < pinmux_maps_num; i++) { + struct pinmux_map const *map = &pinmux_maps[i]; + + if (((map->ctrl_dev == dev) || + !strcmp(map->ctrl_dev_name, devname)) && + map->hog_on_boot) { + /* OK time to hog! */ + ret = pinmux_hog_map(pctldev, map); + if (ret) + return ret; + } + } + return 0; +} + +/** + * pinmux_hog_maps() - unhog specific map entries on controller device + * @pctldev: the pin control device to unhog entries on + */ +void pinmux_unhog_maps(struct pinctrl_dev *pctldev) +{ + struct list_head *node, *tmp; + + mutex_lock(&pctldev->pinmux_hogs_lock); + list_for_each_safe(node, tmp, &pctldev->pinmux_hogs) { + struct pinmux_hog *hog = + list_entry(node, struct pinmux_hog, node); + pinmux_disable(hog->pmx); + pinmux_put(hog->pmx); + list_del(node); + kfree(hog); + } + mutex_unlock(&pctldev->pinmux_hogs_lock); +} + +#ifdef CONFIG_DEBUG_FS + +/* Called from pincontrol core */ +static int pinmux_functions_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + const struct pinmux_ops *pmxops = pctldev->desc->pmxops; + unsigned func_selector = 0; + + while (pmxops->list_functions(pctldev, func_selector) >= 0) { + const char *func = pmxops->get_function_name(pctldev, + func_selector); + const char * const *groups; + unsigned num_groups; + int ret; + int i; + + ret = pmxops->get_function_groups(pctldev, func_selector, + &groups, &num_groups); + if (ret) + seq_printf(s, "function %s: COULD NOT GET GROUPS\n", + func); + + seq_printf(s, "function: %s, groups = [ ", func); + for (i = 0; i < num_groups; i++) + seq_printf(s, "%s ", groups[i]); + seq_puts(s, "]\n"); + + func_selector++; + + } + + return 0; +} + +static int pinmux_pins_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + unsigned pin; + + seq_puts(s, "Pinmux settings per pin\n"); + seq_puts(s, "Format: pin (name): pinmuxfunction\n"); + + /* The highest pin number need to be included in the loop, thus <= */ + for (pin = 0; pin <= pctldev->desc->maxpin; pin++) { + + struct pin_desc *desc; + + desc = pin_desc_get(pctldev, pin); + /* Pin space may be sparse */ + if (desc == NULL) + continue; + + seq_printf(s, "pin %d (%s): %s\n", pin, + desc->name ? desc->name : "unnamed", + desc->mux_requested ? desc->mux_function : "UNCLAIMED"); + } + + return 0; +} + +static int pinmux_hogs_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + struct pinmux_hog *hog; + + seq_puts(s, "Pinmux map hogs held by device\n"); + + list_for_each_entry(hog, &pctldev->pinmux_hogs, node) + seq_printf(s, "%s\n", hog->map->name); + + return 0; +} + +static int pinmux_show(struct seq_file *s, void *what) +{ + struct pinmux *pmx; + + seq_puts(s, "Requested pinmuxes and their maps:\n"); + list_for_each_entry(pmx, &pinmux_list, node) { + struct pinctrl_dev *pctldev = pmx->pctldev; + const struct pinmux_ops *pmxops; + const struct pinctrl_ops *pctlops; + struct pinmux_group *grp; + + if (!pctldev) { + seq_puts(s, "NO PIN CONTROLLER DEVICE\n"); + continue; + } + + pmxops = pctldev->desc->pmxops; + pctlops = pctldev->desc->pctlops; + + seq_printf(s, "device: %s function: %s (%u),", + pinctrl_dev_get_name(pmx->pctldev), + pmxops->get_function_name(pctldev, pmx->func_selector), + pmx->func_selector); + + seq_printf(s, " groups: ["); + list_for_each_entry(grp, &pmx->groups, node) { + seq_printf(s, " %s (%u)", + pctlops->get_group_name(pctldev, grp->group_selector), + grp->group_selector); + } + seq_printf(s, " ]"); + + seq_printf(s, " users: %u map-> %s\n", + pmx->usecount, + pmx->dev ? dev_name(pmx->dev) : "(system)"); + } + + return 0; +} + +static int pinmux_maps_show(struct seq_file *s, void *what) +{ + int i; + + seq_puts(s, "Pinmux maps:\n"); + + for (i = 0; i < pinmux_maps_num; i++) { + struct pinmux_map const *map = &pinmux_maps[i]; + + seq_printf(s, "%s:\n", map->name); + if (map->dev || map->dev_name) + seq_printf(s, " device: %s\n", + map->dev ? dev_name(map->dev) : + map->dev_name); + else + seq_printf(s, " SYSTEM MUX\n"); + seq_printf(s, " controlling device %s\n", + map->ctrl_dev ? dev_name(map->ctrl_dev) : + map->ctrl_dev_name); + seq_printf(s, " function: %s\n", map->function); + seq_printf(s, " group: %s\n", map->group ? map->group : + "(default)"); + } + return 0; +} + +static int pinmux_functions_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinmux_functions_show, inode->i_private); +} + +static int pinmux_pins_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinmux_pins_show, inode->i_private); +} + +static int pinmux_hogs_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinmux_hogs_show, inode->i_private); +} + +static int pinmux_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinmux_show, NULL); +} + +static int pinmux_maps_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinmux_maps_show, NULL); +} + +static const struct file_operations pinmux_functions_ops = { + .open = pinmux_functions_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinmux_pins_ops = { + .open = pinmux_pins_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinmux_hogs_ops = { + .open = pinmux_hogs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinmux_ops = { + .open = pinmux_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinmux_maps_ops = { + .open = pinmux_maps_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +void pinmux_init_device_debugfs(struct dentry *devroot, + struct pinctrl_dev *pctldev) +{ + debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO, + devroot, pctldev, &pinmux_functions_ops); + debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO, + devroot, pctldev, &pinmux_pins_ops); + debugfs_create_file("pinmux-hogs", S_IFREG | S_IRUGO, + devroot, pctldev, &pinmux_hogs_ops); +} + +void pinmux_init_debugfs(struct dentry *subsys_root) +{ + debugfs_create_file("pinmuxes", S_IFREG | S_IRUGO, + subsys_root, NULL, &pinmux_ops); + debugfs_create_file("pinmux-maps", S_IFREG | S_IRUGO, + subsys_root, NULL, &pinmux_maps_ops); +} + +#endif /* CONFIG_DEBUG_FS */ diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h new file mode 100644 index 0000000..844500b --- /dev/null +++ b/drivers/pinctrl/pinmux.h @@ -0,0 +1,47 @@ +/* + * Internal interface between the core pin control system and the + * pinmux portions + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * Based on bits of regulator core, gpio core and clk core + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ +#ifdef CONFIG_PINMUX + +int pinmux_check_ops(const struct pinmux_ops *ops); +void pinmux_init_device_debugfs(struct dentry *devroot, + struct pinctrl_dev *pctldev); +void pinmux_init_debugfs(struct dentry *subsys_root); +int pinmux_hog_maps(struct pinctrl_dev *pctldev); +void pinmux_unhog_maps(struct pinctrl_dev *pctldev); + +#else + +static inline int pinmux_check_ops(const struct pinmux_ops *ops) +{ + return 0; +} + +static inline void pinmux_init_device_debugfs(struct dentry *devroot, + struct pinctrl_dev *pctldev) +{ +} + +static inline void pinmux_init_debugfs(struct dentry *subsys_root) +{ +} + +static inline int pinmux_hog_maps(struct pinctrl_dev *pctldev) +{ + return 0; +} + +static inline void pinmux_unhog_maps(struct pinctrl_dev *pctldev) +{ +} + +#endif diff --git a/include/linux/pinctrl/machine.h b/include/linux/pinctrl/machine.h new file mode 100644 index 0000000..8886353 --- /dev/null +++ b/include/linux/pinctrl/machine.h @@ -0,0 +1,107 @@ +/* + * Machine interface for the pinctrl subsystem. + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * Based on bits of regulator core, gpio core and clk core + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ +#ifndef __LINUX_PINMUX_MACHINE_H +#define __LINUX_PINMUX_MACHINE_H + +/** + * struct pinmux_map - boards/machines shall provide this map for devices + * @name: the name of this specific map entry for the particular machine. + * This is the second parameter passed to pinmux_get() when you want + * to have several mappings to the same device + * @ctrl_dev: the pin control device to be used by this mapping, may be NULL + * if you provide .ctrl_dev_name instead (this is more common) + * @ctrl_dev_name: the name of the device controlling this specific mapping, + * the name must be the same as in your struct device*, may be NULL if + * you provide .ctrl_dev instead + * @function: a function in the driver to use for this mapping, the driver + * will lookup the function referenced by this ID on the specified + * pin control device + * @group: sometimes a function can map to different pin groups, so this + * selects a certain specific pin group to activate for the function, if + * left as NULL, the first applicable group will be used + * @dev: the device using this specific mapping, may be NULL if you provide + * .dev_name instead (this is more common) + * @dev_name: the name of the device using this specific mapping, the name + * must be the same as in your struct device*, may be NULL if you + * provide .dev instead + * @hog_on_boot: if this is set to true, the pin control subsystem will itself + * hog the mappings as the pinmux device drivers are attached, so this is + * typically used with system maps (mux mappings without an assigned + * device) that you want to get hogged and enabled by default as soon as + * a pinmux device supporting it is registered. These maps will not be + * disabled and put until the system shuts down. + */ +struct pinmux_map { + const char *name; + struct device *ctrl_dev; + const char *ctrl_dev_name; + const char *function; + const char *group; + struct device *dev; + const char *dev_name; + const bool hog_on_boot; +}; + +/* + * Convenience macro to set a simple map from a certain pin controller and a + * certain function to a named device + */ +#define PINMUX_MAP(a, b, c, d) \ + { .name = a, .ctrl_dev_name = b, .function = c, .dev_name = d } + +/* + * Convenience macro to map a system function onto a certain pinctrl device. + * System functions are not assigned to a particular device. + */ +#define PINMUX_MAP_SYS(a, b, c) \ + { .name = a, .ctrl_dev_name = b, .function = c } + +/* + * Convenience macro to map a function onto the primary device pinctrl device + * this is especially helpful on systems that have only one pin controller + * or need to set up a lot of mappings on the primary controller. + */ +#define PINMUX_MAP_PRIMARY(a, b, c) \ + { .name = a, .ctrl_dev_name = "pinctrl.0", .function = b, \ + .dev_name = c } + +/* + * Convenience macro to map a system function onto the primary pinctrl device. + * System functions are not assigned to a particular device. + */ +#define PINMUX_MAP_PRIMARY_SYS(a, b) \ + { .name = a, .ctrl_dev_name = "pinctrl.0", .function = b } + +/* + * Convenience macro to map a system function onto the primary pinctrl device, + * to be hogged by the pinmux core until the system shuts down. + */ +#define PINMUX_MAP_PRIMARY_SYS_HOG(a, b) \ + { .name = a, .ctrl_dev_name = "pinctrl.0", .function = b, \ + .hog_on_boot = true } + + +#ifdef CONFIG_PINMUX + +extern int pinmux_register_mappings(struct pinmux_map const *map, + unsigned num_maps); + +#else + +static inline int pinmux_register_mappings(struct pinmux_map const *map, + unsigned num_maps) +{ + return 0; +} + +#endif /* !CONFIG_PINMUX */ +#endif diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h new file mode 100644 index 0000000..4f8d2089 --- /dev/null +++ b/include/linux/pinctrl/pinctrl.h @@ -0,0 +1,133 @@ +/* + * Interface the pinctrl subsystem + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * This interface is used in the core to keep track of pins. + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ +#ifndef __LINUX_PINCTRL_PINCTRL_H +#define __LINUX_PINCTRL_PINCTRL_H + +#ifdef CONFIG_PINCTRL + +#include <linux/radix-tree.h> +#include <linux/spinlock.h> +#include <linux/list.h> +#include <linux/seq_file.h> + +struct pinctrl_dev; +struct pinmux_ops; +struct gpio_chip; + +/** + * struct pinctrl_pin_desc - boards/machines provide information on their + * pins, pads or other muxable units in this struct + * @number: unique pin number from the global pin number space + * @name: a name for this pin + */ +struct pinctrl_pin_desc { + unsigned number; + const char *name; +}; + +/* Convenience macro to define a single named or anonymous pin descriptor */ +#define PINCTRL_PIN(a, b) { .number = a, .name = b } +#define PINCTRL_PIN_ANON(a) { .number = a } + +/** + * struct pinctrl_gpio_range - each pin controller can provide subranges of + * the GPIO number space to be handled by the controller + * @node: list node for internal use + * @name: a name for the chip in this range + * @id: an ID number for the chip in this range + * @base: base offset of the GPIO range + * @npins: number of pins in the GPIO range, including the base number + * @gc: an optional pointer to a gpio_chip + */ +struct pinctrl_gpio_range { + struct list_head node; + const char *name; + unsigned int id; + unsigned int base; + unsigned int npins; + struct gpio_chip *gc; +}; + +/** + * struct pinctrl_ops - global pin control operations, to be implemented by + * pin controller drivers. + * @list_groups: list the number of selectable named groups available + * in this pinmux driver, the core will begin on 0 and call this + * repeatedly as long as it returns >= 0 to enumerate the groups + * @get_group_name: return the group name of the pin group + * @get_group_pins: return an array of pins corresponding to a certain + * group selector @pins, and the size of the array in @num_pins + * @pin_dbg_show: optional debugfs display hook that will provide per-device + * info for a certain pin in debugfs + */ +struct pinctrl_ops { + int (*list_groups) (struct pinctrl_dev *pctldev, unsigned selector); + const char *(*get_group_name) (struct pinctrl_dev *pctldev, + unsigned selector); + int (*get_group_pins) (struct pinctrl_dev *pctldev, + unsigned selector, + unsigned ** const pins, + unsigned * const num_pins); + void (*pin_dbg_show) (struct pinctrl_dev *pctldev, struct seq_file *s, + unsigned offset); +}; + +/** + * struct pinctrl_desc - pin controller descriptor, register this to pin + * control subsystem + * @name: name for the pin controller + * @pins: an array of pin descriptors describing all the pins handled by + * this pin controller + * @npins: number of descriptors in the array, usually just ARRAY_SIZE() + * of the pins field above + * @maxpin: since pin spaces may be sparse, there can he "holes" in the + * pin range, this attribute gives the maximum pin number in the + * total range. This should not be lower than npins for example, + * but may be equal to npins if you have no holes in the pin range. + * @pctlops: pin control operation vtable, to support global concepts like + * grouping of pins, this is optional. + * @pmxops: pinmux operation vtable, if you support pinmuxing in your driver + * @owner: module providing the pin controller, used for refcounting + */ +struct pinctrl_desc { + const char *name; + struct pinctrl_pin_desc const *pins; + unsigned int npins; + unsigned int maxpin; + struct pinctrl_ops *pctlops; + struct pinmux_ops *pmxops; + struct module *owner; +}; + +/* External interface to pin controller */ +extern struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc, + struct device *dev, void *driver_data); +extern void pinctrl_unregister(struct pinctrl_dev *pctldev); +extern bool pin_is_valid(struct pinctrl_dev *pctldev, int pin); +extern void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range); +extern void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range); +extern const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev); +extern void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev); +#else + + +/* Sufficiently stupid default function when pinctrl is not in use */ +static inline bool pin_is_valid(struct pinctrl_dev *pctldev, int pin) +{ + return pin >= 0; +} + +#endif /* !CONFIG_PINCTRL */ + +#endif /* __LINUX_PINCTRL_PINCTRL_H */ diff --git a/include/linux/pinctrl/pinmux.h b/include/linux/pinctrl/pinmux.h new file mode 100644 index 0000000..3c430e7 --- /dev/null +++ b/include/linux/pinctrl/pinmux.h @@ -0,0 +1,117 @@ +/* + * Interface the pinmux subsystem + * + * Copyright (C) 2011 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * Based on bits of regulator core, gpio core and clk core + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ +#ifndef __LINUX_PINCTRL_PINMUX_H +#define __LINUX_PINCTRL_PINMUX_H + +#include <linux/list.h> +#include <linux/seq_file.h> +#include "pinctrl.h" + +/* This struct is private to the core and should be regarded as a cookie */ +struct pinmux; + +#ifdef CONFIG_PINMUX + +struct pinctrl_dev; + +/** + * struct pinmux_ops - pinmux operations, to be implemented by pin controller + * drivers that support pinmuxing + * @request: called by the core to see if a certain pin can be made available + * available for muxing. This is called by the core to acquire the pins + * before selecting any actual mux setting across a function. The driver + * is allowed to answer "no" by returning a negative error code + * @free: the reverse function of the request() callback, frees a pin after + * being requested + * @list_functions: list the number of selectable named functions available + * in this pinmux driver, the core will begin on 0 and call this + * repeatedly as long as it returns >= 0 to enumerate mux settings + * @get_function_name: return the function name of the muxing selector, + * called by the core to figure out which mux setting it shall map a + * certain device to + * @get_function_groups: return an array of groups names (in turn + * referencing pins) connected to a certain function selector. The group + * name can be used with the generic @pinctrl_ops to retrieve the + * actual pins affected. The applicable groups will be returned in + * @groups and the number of groups in @num_groups + * @enable: enable a certain muxing function with a certain pin group. The + * driver does not need to figure out whether enabling this function + * conflicts some other use of the pins in that group, such collisions + * are handled by the pinmux subsystem. The @func_selector selects a + * certain function whereas @group_selector selects a certain set of pins + * to be used. On simple controllers the latter argument may be ignored + * @disable: disable a certain muxing selector with a certain pin group + * @gpio_request_enable: requests and enables GPIO on a certain pin. + * Implement this only if you can mux every pin individually as GPIO. The + * affected GPIO range is passed along with an offset into that + * specific GPIO range - function selectors and pin groups are orthogonal + * to this, the core will however make sure the pins do not collide + */ +struct pinmux_ops { + int (*request) (struct pinctrl_dev *pctldev, unsigned offset); + int (*free) (struct pinctrl_dev *pctldev, unsigned offset); + int (*list_functions) (struct pinctrl_dev *pctldev, unsigned selector); + const char *(*get_function_name) (struct pinctrl_dev *pctldev, + unsigned selector); + int (*get_function_groups) (struct pinctrl_dev *pctldev, + unsigned selector, + const char * const **groups, + unsigned * const num_groups); + int (*enable) (struct pinctrl_dev *pctldev, unsigned func_selector, + unsigned group_selector); + void (*disable) (struct pinctrl_dev *pctldev, unsigned func_selector, + unsigned group_selector); + int (*gpio_request_enable) (struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range, + unsigned offset); +}; + +/* External interface to pinmux */ +extern int pinmux_request_gpio(unsigned gpio); +extern void pinmux_free_gpio(unsigned gpio); +extern struct pinmux * __must_check pinmux_get(struct device *dev, const char *name); +extern void pinmux_put(struct pinmux *pmx); +extern int pinmux_enable(struct pinmux *pmx); +extern void pinmux_disable(struct pinmux *pmx); + +#else /* !CONFIG_PINMUX */ + +static inline int pinmux_request_gpio(unsigned gpio) +{ + return 0; +} + +static inline void pinmux_free_gpio(unsigned gpio) +{ +} + +static inline struct pinmux * __must_check pinmux_get(struct device *dev, const char *name) +{ + return NULL; +} + +static inline void pinmux_put(struct pinmux *pmx) +{ +} + +static inline int pinmux_enable(struct pinmux *pmx) +{ + return 0; +} + +static inline void pinmux_disable(struct pinmux *pmx) +{ +} + +#endif /* CONFIG_PINMUX */ + +#endif /* __LINUX_PINCTRL_PINMUX_H */ |
