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| author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-07-31 17:08:50 -0300 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2019-07-31 14:13:13 -0600 |
| commit | 9cdd273e29f3b901712ec3c298b1d506861f48e3 (patch) | |
| tree | c2dc7b819892ee63e43430cd34a46026d081b069 /Documentation/spi/spi-sc18is602.rst | |
| parent | d2fd3732e4acd6ab72960e7f8e00845438803f3e (diff) | |
spi: docs: convert to ReST and add it to the kABI bookset
While there's one file there with briefily describes the uAPI,
the documentation was written just like most subsystems: focused
on kernel developers. So, add it together with driver-api books.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/spi/spi-sc18is602.rst')
| -rw-r--r-- | Documentation/spi/spi-sc18is602.rst | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/spi/spi-sc18is602.rst b/Documentation/spi/spi-sc18is602.rst new file mode 100644 index 000000000000..2a31dc722321 --- /dev/null +++ b/Documentation/spi/spi-sc18is602.rst @@ -0,0 +1,39 @@ +=========================== +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.rst 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. |