diff options
author | Linus Walleij <linus.walleij@linaro.org> | 2011-10-19 18:14:33 +0200 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2012-01-03 09:10:04 +0100 |
commit | ae6b4d8588f4fc95520b0e62c4b1f474c82191a9 (patch) | |
tree | 3da8e553a6374f02e89b5a6ba52b83f34c3abea2 /drivers | |
parent | b4e3ac74d5cd4152f2ec6b3280b1ff3428952f7f (diff) | |
download | op-kernel-dev-ae6b4d8588f4fc95520b0e62c4b1f474c82191a9.zip op-kernel-dev-ae6b4d8588f4fc95520b0e62c4b1f474c82191a9.tar.gz |
pinctrl: add a pin config interface
This add per-pin and per-group pin config interfaces for biasing,
driving and other such electronic properties. The details of passed
configurations are passed in an opaque unsigned long which may be
dereferences to integer types, structs or lists on either side
of the configuration interface.
ChangeLog v1->v2:
- Clear split of terminology: we now have pin controllers, and
those may support two interfaces using vtables: pin
multiplexing and pin configuration.
- Break out pin configuration to its own C file, controllers may
implement only config without mux, and vice versa, so keep each
sub-functionality of pin controllers separate. Introduce
CONFIG_PINCONF in Kconfig.
- Implement some core logic around pin configuration in the
pinconf.c file.
- Remove UNKNOWN config states, these were just surplus baggage.
- Remove FLOAT config state - HIGH_IMPEDANCE should be enough for
everyone.
- PIN_CONFIG_POWER_SOURCE added to handle switching the power
supply for the pin logic between different sources
- Explicit DISABLE config enums to turn schmitt-trigger,
wakeup etc OFF.
- Update documentation to reflect all the recent reasoning.
ChangeLog v2->v3:
- Twist API around to pass around arrays of config tuples instead
of (param, value) pairs everywhere.
- Explicit drive strength semantics for push/pull and similar
drive modes, this shall be the number of drive stages vs
nominal load impedance, which should match the actual
electronics used in push/pull CMOS or TTY totempoles.
- Drop load capacitance configuration - I probably don't know
what I'm doing here so leave it out.
- Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to
PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off.
- Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined
argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead.
- Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use
PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off.
- Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time
on input lines.
- Fix a bug when we tried to configure pins for pin controllers
without pinconf support.
- Initialized debugfs properly so it works.
- Initialize the mutex properly and lock around config tampering
sections.
- Check the return value from get_initial_config() properly.
ChangeLog v3->v4:
- Export the pin_config_get(), pin_config_set() and
pin_config_group() functions.
- Drop the entire concept of just getting initial config and
keeping track of pin states internally, instead ask the pins
what state they are in. Previous idea was plain wrong, if the
device cannot keep track of its state, the driver should do
it.
- Drop the generic configuration layout, it seems this impose
too much restriction on some pin controllers, so let them do
things the way they want and split off support for generic
config as an optional add-on.
ChangeLog v4->v5:
- Introduce two symmetric driver calls for group configuration,
.pin_config_group_[get|set] and corresponding external calls.
- Remove generic semantic meanings of return values from config
calls, these belong in the generic config patch. Just pass the
return value through instead.
- Add a debugfs entry "pinconf-groups" to read status from group
configuration only, also slam in a per-group debug callback in
the pinconf_ops so custom drivers can display something
meaningful for their pins.
- Fix some dangling newline.
- Drop dangling #else clause.
- Update documentation to match the above.
ChangeLog v5->v6:
- Change to using a pin name as parameter for the
[get|set]_config() functions, as suggested by Stephen Warren.
This is more natural as names will be what a developer has
access to in written documentation etc.
ChangeLog v6->v7:
- Refactor out by-pin and by-name get/set functions, only expose
the by-name functions externally, expose the by-pin functions
internally.
- Show supported pin control functionality in the debugfs
pinctrl-devices file.
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/pinctrl/Kconfig | 5 | ||||
-rw-r--r-- | drivers/pinctrl/Makefile | 1 | ||||
-rw-r--r-- | drivers/pinctrl/core.c | 43 | ||||
-rw-r--r-- | drivers/pinctrl/core.h | 5 | ||||
-rw-r--r-- | drivers/pinctrl/pinconf.c | 302 | ||||
-rw-r--r-- | drivers/pinctrl/pinconf.h | 36 |
6 files changed, 390 insertions, 2 deletions
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig index e963da4..c63c721 100644 --- a/drivers/pinctrl/Kconfig +++ b/drivers/pinctrl/Kconfig @@ -12,7 +12,10 @@ menu "Pin controllers" depends on PINCTRL config PINMUX - bool "Support pinmux controllers" + bool "Support pin multiplexing controllers" + +config PINCONF + bool "Support pin configuration controllers" config DEBUG_PINCTRL bool "Debug PINCTRL calls" diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile index 5f3e4d6..c046f78 100644 --- a/drivers/pinctrl/Makefile +++ b/drivers/pinctrl/Makefile @@ -4,6 +4,7 @@ ccflags-$(CONFIG_DEBUG_PINCTRL) += -DDEBUG obj-$(CONFIG_PINCTRL) += core.o obj-$(CONFIG_PINMUX) += pinmux.o +obj-$(CONFIG_PINCONF) += pinconf.o obj-$(CONFIG_PINMUX_SIRF) += pinmux-sirf.o obj-$(CONFIG_PINMUX_U300) += pinmux-u300.o obj-$(CONFIG_PINCTRL_COH901) += pinctrl-coh901.o diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 4955a68..034b1ad 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -28,6 +28,7 @@ #include <linux/pinctrl/machine.h> #include "core.h" #include "pinmux.h" +#include "pinconf.h" /* Global list of pin control devices */ static DEFINE_MUTEX(pinctrldev_list_mutex); @@ -101,6 +102,30 @@ struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, unsigned int pin) } /** + * pin_get_from_name() - look up a pin number from a name + * @pctldev: the pin control device to lookup the pin on + * @name: the name of the pin to look up + */ +int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name) +{ + unsigned pin; + + /* 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; + if (desc->name && !strcmp(name, desc->name)) + return pin; + } + + return -EINVAL; +} + +/** * 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 @@ -160,6 +185,7 @@ static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev, pindesc = kzalloc(sizeof(*pindesc), GFP_KERNEL); if (pindesc == NULL) return -ENOMEM; + spin_lock_init(&pindesc->lock); /* Set owner */ @@ -409,11 +435,15 @@ static int pinctrl_devices_show(struct seq_file *s, void *what) { struct pinctrl_dev *pctldev; - seq_puts(s, "name [pinmux]\n"); + seq_puts(s, "name [pinmux] [pinconf]\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 "); + if (pctldev->desc->confops) seq_puts(s, "yes"); else seq_puts(s, "no"); @@ -492,6 +522,7 @@ static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev) debugfs_create_file("gpio-ranges", S_IFREG | S_IRUGO, device_root, pctldev, &pinctrl_gpioranges_ops); pinmux_init_device_debugfs(device_root, pctldev); + pinconf_init_device_debugfs(device_root, pctldev); } static void pinctrl_init_debugfs(void) @@ -548,6 +579,16 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc, } } + /* If we're implementing pinconfig, check the ops for sanity */ + if (pctldesc->confops) { + ret = pinconf_check_ops(pctldesc->confops); + if (ret) { + pr_err("%s pin config ops lacks necessary functions\n", + pctldesc->name); + return NULL; + } + } + pctldev = kzalloc(sizeof(struct pinctrl_dev), GFP_KERNEL); if (pctldev == NULL) return NULL; diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h index 74dee43..3f5b911 100644 --- a/drivers/pinctrl/core.h +++ b/drivers/pinctrl/core.h @@ -9,6 +9,10 @@ * License terms: GNU General Public License (GPL) version 2 */ +#include <linux/pinctrl/pinconf.h> + +struct pinctrl_gpio_range; + /** * struct pinctrl_dev - pin control class device * @node: node to include this pin controller in the global pin controller list @@ -66,6 +70,7 @@ struct pin_desc { 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, unsigned int pin); +int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name); int pinctrl_get_device_gpio_range(unsigned gpio, struct pinctrl_dev **outdev, struct pinctrl_gpio_range **outrange); diff --git a/drivers/pinctrl/pinconf.c b/drivers/pinctrl/pinconf.c new file mode 100644 index 0000000..9195eef --- /dev/null +++ b/drivers/pinctrl/pinconf.c @@ -0,0 +1,302 @@ +/* + * Core driver for the pin config portions of 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 + */ +#define pr_fmt(fmt) "pinconfig core: " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <linux/pinctrl/machine.h> +#include <linux/pinctrl/pinctrl.h> +#include <linux/pinctrl/pinconf.h> +#include "core.h" +#include "pinconf.h" + +int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin, + unsigned long *config) +{ + const struct pinconf_ops *ops = pctldev->desc->confops; + + if (!ops || !ops->pin_config_get) { + dev_err(&pctldev->dev, "cannot get pin configuration, missing " + "pin_config_get() function in driver\n"); + return -EINVAL; + } + + return ops->pin_config_get(pctldev, pin, config); +} + +/** + * pin_config_get() - get the configuration of a single pin parameter + * @pctldev: pin controller device for this pin + * @name: name of the pin to get the config for + * @config: the config pointed to by this argument will be filled in with the + * current pin state, it can be used directly by drivers as a numeral, or + * it can be dereferenced to any struct. + */ +int pin_config_get(struct pinctrl_dev *pctldev, const char *name, + unsigned long *config) +{ + int pin; + + pin = pin_get_from_name(pctldev, name); + if (pin < 0) + return pin; + + return pin_config_get_for_pin(pctldev, pin, config); +} +EXPORT_SYMBOL(pin_config_get); + +int pin_config_set_for_pin(struct pinctrl_dev *pctldev, unsigned pin, + unsigned long config) +{ + const struct pinconf_ops *ops = pctldev->desc->confops; + int ret; + + if (!ops || !ops->pin_config_set) { + dev_err(&pctldev->dev, "cannot configure pin, missing " + "config function in driver\n"); + return -EINVAL; + } + + ret = ops->pin_config_set(pctldev, pin, config); + if (ret) { + dev_err(&pctldev->dev, + "unable to set pin configuration on pin %d\n", pin); + return ret; + } + + return 0; +} + +/** + * pin_config_set() - set the configuration of a single pin parameter + * @pctldev: pin controller device for this pin + * @name: name of the pin to set the config for + * @config: the config in this argument will contain the desired pin state, it + * can be used directly by drivers as a numeral, or it can be dereferenced + * to any struct. + */ +int pin_config_set(struct pinctrl_dev *pctldev, const char *name, + unsigned long config) +{ + int pin; + + pin = pin_get_from_name(pctldev, name); + if (pin < 0) + return pin; + + return pin_config_set_for_pin(pctldev, pin, config); +} +EXPORT_SYMBOL(pin_config_set); + +int pin_config_group_get(struct pinctrl_dev *pctldev, const char *pin_group, + unsigned long *config) +{ + const struct pinconf_ops *ops = pctldev->desc->confops; + int selector; + + if (!ops || !ops->pin_config_group_get) { + dev_err(&pctldev->dev, "cannot get configuration for pin " + "group, missing group config get function in " + "driver\n"); + return -EINVAL; + } + + selector = pinctrl_get_group_selector(pctldev, pin_group); + if (selector < 0) + return selector; + + return ops->pin_config_group_get(pctldev, selector, config); +} +EXPORT_SYMBOL(pin_config_group_get); + + +int pin_config_group_set(struct pinctrl_dev *pctldev, const char *pin_group, + unsigned long config) +{ + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + const struct pinconf_ops *ops = pctldev->desc->confops; + int selector; + const unsigned *pins; + unsigned num_pins; + int ret; + int i; + + if (!ops || (!ops->pin_config_group_set && !ops->pin_config_set)) { + dev_err(&pctldev->dev, "cannot configure pin group, missing " + "config function in driver\n"); + return -EINVAL; + } + + selector = pinctrl_get_group_selector(pctldev, pin_group); + if (selector < 0) + return selector; + + ret = pctlops->get_group_pins(pctldev, selector, &pins, &num_pins); + if (ret) { + dev_err(&pctldev->dev, "cannot configure pin group, error " + "getting pins\n"); + return ret; + } + + /* + * If the pin controller supports handling entire groups we use that + * capability. + */ + if (ops->pin_config_group_set) { + ret = ops->pin_config_group_set(pctldev, selector, config); + /* + * If the pin controller prefer that a certain group be handled + * pin-by-pin as well, it returns -EAGAIN. + */ + if (ret != -EAGAIN) + return ret; + } + + /* + * If the controller cannot handle entire groups, we configure each pin + * individually. + */ + if (!ops->pin_config_set) + return 0; + + for (i = 0; i < num_pins; i++) { + ret = ops->pin_config_set(pctldev, pins[i], config); + if (ret < 0) + return ret; + } + + return 0; +} +EXPORT_SYMBOL(pin_config_group_set); + +int pinconf_check_ops(const struct pinconf_ops *ops) +{ + /* We must be able to read out pin status */ + if (!ops->pin_config_get && !ops->pin_config_group_get) + return -EINVAL; + /* We have to be able to config the pins in SOME way */ + if (!ops->pin_config_set && !ops->pin_config_group_set) + return -EINVAL; + return 0; +} + +#ifdef CONFIG_DEBUG_FS + +static void pinconf_dump_pin(struct pinctrl_dev *pctldev, + struct seq_file *s, int pin) +{ + const struct pinconf_ops *ops = pctldev->desc->confops; + + if (ops && ops->pin_config_dbg_show) + ops->pin_config_dbg_show(pctldev, s, pin); +} + +static int pinconf_pins_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + unsigned pin; + + seq_puts(s, "Pin config settings per pin\n"); + seq_puts(s, "Format: pin (name): pinmux setting array\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):", pin, + desc->name ? desc->name : "unnamed"); + + pinconf_dump_pin(pctldev, s, pin); + + seq_printf(s, "\n"); + } + + return 0; +} + +static void pinconf_dump_group(struct pinctrl_dev *pctldev, + struct seq_file *s, unsigned selector, + const char *gname) +{ + const struct pinconf_ops *ops = pctldev->desc->confops; + + if (ops && ops->pin_config_group_dbg_show) + ops->pin_config_group_dbg_show(pctldev, s, selector); +} + +static int pinconf_groups_show(struct seq_file *s, void *what) +{ + struct pinctrl_dev *pctldev = s->private; + const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + const struct pinconf_ops *ops = pctldev->desc->confops; + unsigned selector = 0; + + if (!ops || !ops->pin_config_group_get) + return 0; + + seq_puts(s, "Pin config settings per pin group\n"); + seq_puts(s, "Format: group (name): pinmux setting array\n"); + + while (pctlops->list_groups(pctldev, selector) >= 0) { + const char *gname = pctlops->get_group_name(pctldev, selector); + + seq_printf(s, "%u (%s):", selector, gname); + pinconf_dump_group(pctldev, s, selector, gname); + selector++; + } + + return 0; +} + +static int pinconf_pins_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinconf_pins_show, inode->i_private); +} + +static int pinconf_groups_open(struct inode *inode, struct file *file) +{ + return single_open(file, pinconf_groups_show, inode->i_private); +} + +static const struct file_operations pinconf_pins_ops = { + .open = pinconf_pins_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations pinconf_groups_ops = { + .open = pinconf_groups_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +void pinconf_init_device_debugfs(struct dentry *devroot, + struct pinctrl_dev *pctldev) +{ + debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO, + devroot, pctldev, &pinconf_pins_ops); + debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO, + devroot, pctldev, &pinconf_groups_ops); +} + +#endif diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h new file mode 100644 index 0000000..e7dc616 --- /dev/null +++ b/drivers/pinctrl/pinconf.h @@ -0,0 +1,36 @@ +/* + * Internal interface between the core pin control system and the + * pin config 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_PINCONF + +int pinconf_check_ops(const struct pinconf_ops *ops); +void pinconf_init_device_debugfs(struct dentry *devroot, + struct pinctrl_dev *pctldev); +int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin, + unsigned long *config); +int pin_config_set_for_pin(struct pinctrl_dev *pctldev, unsigned pin, + unsigned long config); + +#else + +static inline int pinconf_check_ops(const struct pinconf_ops *ops) +{ + return 0; +} + +static inline void pinconf_init_device_debugfs(struct dentry *devroot, + struct pinctrl_dev *pctldev) +{ +} + +#endif |