On Tue, Apr 10, 2018 at 7:07 PM, H. Nikolaus Schaller hns@goldelico.com wrote:
PCAL chips ("L" seems to stand for "latched") have additional registers starting at address 0x40 to control the latches, interrupt mask, pull-up and pull down etc.
The constants are so far defined in a way that they fit for the pcal9555a when shifted by the number of banks, i.e. multiplied by 2.
Now the pcal6524 has 3 banks which means the relative offset must be multiplied by 4 which gives a wrong result if not done carefully, since the base offset is already included in the offset.
For the basic registers shared with all pca93xx/tca64xx chips there is no such offset.
Therefore, we add code to adjust the register number for exended registers to the 24 bit accessor functions.
And we add additional register offset constants (not yet used by the driver code) which are specific to the pcal6524.
First of all, as I said, please split this to two patches. Don't mix the things.
/* adjust register address for pcal6524 */if (reg >= PCAL953X_OUT_STRENGTH)reg -= PCAL953X_OUT_STRENGTH >> 1;
Give me some days to think about it.