From 3ce8859e2e72713d3619285cab609d05c3591fc4 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Sat, 18 Aug 2012 09:06:27 -0700 Subject: 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 Signed-off-by: Mark Brown --- Documentation/spi/spi-sc18is602 | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 Documentation/spi/spi-sc18is602 (limited to 'Documentation/spi') 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 + + +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. -- cgit v1.2.3