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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>
40 lines
1.3 KiB
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40 lines
1.3 KiB
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===========================
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Kernel driver spi-sc18is602
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===========================
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Supported chips:
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* NXP SI18IS602/602B/603
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Datasheet: http://www.nxp.com/documents/data_sheet/SC18IS602_602B_603.pdf
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Author:
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Guenter Roeck <linux@roeck-us.net>
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Description
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-----------
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This driver provides connects a NXP SC18IS602/603 I2C-bus to SPI bridge to the
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kernel's SPI core subsystem.
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The driver does not probe for supported chips, since the SI18IS602/603 does not
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support Chip ID registers. You will have to instantiate the devices explicitly.
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Please see Documentation/i2c/instantiating-devices.rst for details.
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Usage Notes
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-----------
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This driver requires the I2C adapter driver to support raw I2C messages. I2C
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adapter drivers which can only handle the SMBus protocol are not supported.
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The maximum SPI message size supported by SC18IS602/603 is 200 bytes. Attempts
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to initiate longer transfers will fail with -EINVAL. EEPROM read operations and
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similar large accesses have to be split into multiple chunks of no more than
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200 bytes per SPI message (128 bytes of data per message is recommended). This
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means that programs such as "cp" or "od", which automatically use large block
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sizes to access a device, can not be used directly to read data from EEPROM.
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Programs such as dd, where the block size can be specified, should be used
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instead.
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