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9cdd273e | 1 | =========================== |
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2 | Kernel driver spi-sc18is602 |
3 | =========================== | |
4 | ||
5 | Supported chips: | |
9cdd273e | 6 | |
3ce8859e | 7 | * NXP SI18IS602/602B/603 |
9cdd273e | 8 | |
3ea4eac3 | 9 | Datasheet: https://www.nxp.com/documents/data_sheet/SC18IS602_602B_603.pdf |
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10 | |
11 | Author: | |
12 | Guenter Roeck <linux@roeck-us.net> | |
13 | ||
14 | ||
15 | Description | |
16 | ----------- | |
17 | ||
18 | This driver provides connects a NXP SC18IS602/603 I2C-bus to SPI bridge to the | |
19 | kernel's SPI core subsystem. | |
20 | ||
21 | The driver does not probe for supported chips, since the SI18IS602/603 does not | |
22 | support Chip ID registers. You will have to instantiate the devices explicitly. | |
ccf988b6 | 23 | Please see Documentation/i2c/instantiating-devices.rst for details. |
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24 | |
25 | ||
26 | Usage Notes | |
27 | ----------- | |
28 | ||
29 | This driver requires the I2C adapter driver to support raw I2C messages. I2C | |
30 | adapter drivers which can only handle the SMBus protocol are not supported. | |
31 | ||
32 | The maximum SPI message size supported by SC18IS602/603 is 200 bytes. Attempts | |
33 | to initiate longer transfers will fail with -EINVAL. EEPROM read operations and | |
34 | similar large accesses have to be split into multiple chunks of no more than | |
35 | 200 bytes per SPI message (128 bytes of data per message is recommended). This | |
36 | means that programs such as "cp" or "od", which automatically use large block | |
37 | sizes to access a device, can not be used directly to read data from EEPROM. | |
38 | Programs such as dd, where the block size can be specified, should be used | |
39 | instead. |