Hi, I am planning to add SPI support for da7210 codec driver. SPI for this codec has slightly different format than others. It has 8 bit register address and 8 bit data. Out of 8 bits of register address, one bit (i.e. LSB) is used to indicate read or write. Value of 1 at LSB denotes READ while value of 0 at LSB denotes write operation.
Thus in order for SPI READ to work correctly, the register address need to be left shifted by one and then ORed with 0x1. In the same way for SPI WRITE to work correctly, it need to be left shifted by one.
I have gone though the regmap sources and found that ORing can be achieved by setting correct read_flag_mask. But I couldn't find anything by which I can tell regmap core to shift the register address before ORing it with read_flag_mask. Am I missing anything here?
Is there any other way to achieve this using regmap? The only other way I can think of is providing a wrapper function to read and write in codec driver and doing the shifting job inside that wrapper.
TIA!