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| author | Guenter Roeck <linux@roeck-us.net> | 2012-08-18 09:06:27 -0700 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2012-08-22 19:34:51 +0100 |
| commit | 3ce8859e2e72713d3619285cab609d05c3591fc4 (patch) | |
| tree | c5ac44e96198137f34559e1fd493c9d6b02960b1 /Documentation/spi | |
| parent | 21879213652aca6e3fe250fc8e02c68e71c5e18a (diff) | |
| download | linux-3ce8859e2e72713d3619285cab609d05c3591fc4.tar.bz2 | |
spi: Master driver for NXP SC18IS602/603
This driver adds support for NXP SC18IS602/603 I2C to SPI bus bridge.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'Documentation/spi')
| -rw-r--r-- | Documentation/spi/spi-sc18is602 | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/spi/spi-sc18is602 b/Documentation/spi/spi-sc18is602 new file mode 100644 index 000000000000..a45702865a38 --- /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. |