diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-bus.txt | 3 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-gpio.txt | 29 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi-sc18is602.txt | 23 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/spi/spi_pl022.txt | 22 | ||||
| -rw-r--r-- | Documentation/spi/spi-sc18is602 | 36 |
5 files changed, 113 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/spi-bus.txt b/Documentation/devicetree/bindings/spi/spi-bus.txt index e782add..d2c33d0 100644 --- a/Documentation/devicetree/bindings/spi/spi-bus.txt +++ b/Documentation/devicetree/bindings/spi/spi-bus.txt @@ -21,6 +21,9 @@ assumption that board specific platform code will be used to manage chip selects. Individual drivers can define additional properties to support describing the chip select layout. +Optional property: +- num-cs : total number of chipselects + SPI slave nodes must be children of the SPI master node and can contain the following properties. - reg - (required) chip select address of device. diff --git a/Documentation/devicetree/bindings/spi/spi-gpio.txt b/Documentation/devicetree/bindings/spi/spi-gpio.txt new file mode 100644 index 0000000..8a824be --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-gpio.txt @@ -0,0 +1,29 @@ +SPI-GPIO devicetree bindings + +Required properties: + + - compatible: should be set to "spi-gpio" + - #address-cells: should be set to <0x1> + - ranges + - gpio-sck: GPIO spec for the SCK line to use + - gpio-miso: GPIO spec for the MISO line to use + - gpio-mosi: GPIO spec for the MOSI line to use + - cs-gpios: GPIOs to use for chipselect lines + - num-chipselects: number of chipselect lines + +Example: + + spi { + compatible = "spi-gpio"; + #address-cells = <0x1>; + ranges; + + gpio-sck = <&gpio 95 0>; + gpio-miso = <&gpio 98 0>; + gpio-mosi = <&gpio 97 0>; + cs-gpios = <&gpio 125 0>; + num-chipselects = <1>; + + /* clients */ + }; + diff --git a/Documentation/devicetree/bindings/spi/spi-sc18is602.txt b/Documentation/devicetree/bindings/spi/spi-sc18is602.txt new file mode 100644 index 0000000..02f9033 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/spi-sc18is602.txt @@ -0,0 +1,23 @@ +NXP SC18IS602/SCIS603 + +Required properties: + - compatible : Should be one of + "nxp,sc18is602" + "nxp,sc18is602b" + "nxp,sc18is603" + - reg: I2C bus address + +Optional properties: + - clock-frequency : external oscillator clock frequency. If not + specified, the SC18IS602 default frequency (7372000) will be used. + +The clock-frequency property is relevant and needed only if the chip has an +external oscillator (SC18IS603). + +Example: + + sc18is603@28 { + compatible = "nxp,sc18is603"; + reg = <0x28>; + clock-frequency = <14744000>; + } diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt index 306ec3f..f158fd3 100644 --- a/Documentation/devicetree/bindings/spi/spi_pl022.txt +++ b/Documentation/devicetree/bindings/spi/spi_pl022.txt @@ -6,7 +6,29 @@ Required properties: - interrupts : Should contain SPI controller interrupt Optional properties: +- num-cs : total number of chipselects - cs-gpios : should specify GPIOs used for chipselects. The gpios will be referred to as reg = <index> in the SPI child nodes. If unspecified, a single SPI device without a chip select can be used. +- pl022,autosuspend-delay : delay in ms following transfer completion before + the runtime power management system suspends the + device. A setting of 0 indicates no delay and the + device will be suspended immediately +- pl022,rt : indicates the controller should run the message pump with realtime + priority to minimise the transfer latency on the bus (boolean) + + +SPI slave nodes must be children of the SPI master node and can +contain the following properties. + +- pl022,interface : interface type: + 0: SPI + 1: Texas Instruments Synchronous Serial Frame Format + 2: Microwire (Half Duplex) +- pl022,com-mode : polling, interrupt or dma +- pl022,rx-level-trig : Rx FIFO watermark level +- pl022,tx-level-trig : Tx FIFO watermark level +- pl022,ctrl-len : Microwire interface: Control length +- pl022,wait-state : Microwire interface: Wait state +- pl022,duplex : Microwire interface: Full/Half duplex diff --git a/Documentation/spi/spi-sc18is602 b/Documentation/spi/spi-sc18is602 new file mode 100644 index 0000000..a457028 --- /dev/null +++ b/Documentation/spi/spi-sc18is602 @@ -0,0 +1,36 @@ +Kernel driver spi-sc18is602 +=========================== + +Supported chips: + * NXP SI18IS602/602B/603 + Datasheet: http://www.nxp.com/documents/data_sheet/SC18IS602_602B_603.pdf + +Author: + Guenter Roeck <linux@roeck-us.net> + + +Description +----------- + +This driver provides connects a NXP SC18IS602/603 I2C-bus to SPI bridge to the +kernel's SPI core subsystem. + +The driver does not probe for supported chips, since the SI18IS602/603 does not +support Chip ID registers. You will have to instantiate the devices explicitly. +Please see Documentation/i2c/instantiating-devices for details. + + +Usage Notes +----------- + +This driver requires the I2C adapter driver to support raw I2C messages. I2C +adapter drivers which can only handle the SMBus protocol are not supported. + +The maximum SPI message size supported by SC18IS602/603 is 200 bytes. Attempts +to initiate longer transfers will fail with -EINVAL. EEPROM read operations and +similar large accesses have to be split into multiple chunks of no more than +200 bytes per SPI message (128 bytes of data per message is recommended). This +means that programs such as "cp" or "od", which automatically use large block +sizes to access a device, can not be used directly to read data from EEPROM. +Programs such as dd, where the block size can be specified, should be used +instead. |
