1*4882a593Smuzhiyun=========================== 2*4882a593SmuzhiyunKernel driver spi-sc18is602 3*4882a593Smuzhiyun=========================== 4*4882a593Smuzhiyun 5*4882a593SmuzhiyunSupported chips: 6*4882a593Smuzhiyun 7*4882a593Smuzhiyun * NXP SI18IS602/602B/603 8*4882a593Smuzhiyun 9*4882a593Smuzhiyun Datasheet: https://www.nxp.com/documents/data_sheet/SC18IS602_602B_603.pdf 10*4882a593Smuzhiyun 11*4882a593SmuzhiyunAuthor: 12*4882a593Smuzhiyun Guenter Roeck <linux@roeck-us.net> 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun 15*4882a593SmuzhiyunDescription 16*4882a593Smuzhiyun----------- 17*4882a593Smuzhiyun 18*4882a593SmuzhiyunThis driver provides connects a NXP SC18IS602/603 I2C-bus to SPI bridge to the 19*4882a593Smuzhiyunkernel's SPI core subsystem. 20*4882a593Smuzhiyun 21*4882a593SmuzhiyunThe driver does not probe for supported chips, since the SI18IS602/603 does not 22*4882a593Smuzhiyunsupport Chip ID registers. You will have to instantiate the devices explicitly. 23*4882a593SmuzhiyunPlease see Documentation/i2c/instantiating-devices.rst for details. 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun 26*4882a593SmuzhiyunUsage Notes 27*4882a593Smuzhiyun----------- 28*4882a593Smuzhiyun 29*4882a593SmuzhiyunThis driver requires the I2C adapter driver to support raw I2C messages. I2C 30*4882a593Smuzhiyunadapter drivers which can only handle the SMBus protocol are not supported. 31*4882a593Smuzhiyun 32*4882a593SmuzhiyunThe maximum SPI message size supported by SC18IS602/603 is 200 bytes. Attempts 33*4882a593Smuzhiyunto initiate longer transfers will fail with -EINVAL. EEPROM read operations and 34*4882a593Smuzhiyunsimilar large accesses have to be split into multiple chunks of no more than 35*4882a593Smuzhiyun200 bytes per SPI message (128 bytes of data per message is recommended). This 36*4882a593Smuzhiyunmeans that programs such as "cp" or "od", which automatically use large block 37*4882a593Smuzhiyunsizes to access a device, can not be used directly to read data from EEPROM. 38*4882a593SmuzhiyunPrograms such as dd, where the block size can be specified, should be used 39*4882a593Smuzhiyuninstead. 40