* Jun Nie <[email protected]> [150706 02:21]: > 2015-07-06 17:03 GMT+08:00 Tony Lindgren <[email protected]>: > > * Jun Nie <[email protected]> [150706 01:43]: > >> 2015-06-23 18:18 GMT+08:00 Jun Nie <[email protected]>: > >> > 2015-06-23 18:14 GMT+08:00 Tony Lindgren <[email protected]>: > >> >> * Jun Nie <[email protected]> [150623 02:56]: > >> >>> 2015-06-17 15:17 GMT+08:00 Tony Lindgren <[email protected]>: > >> >>> > * Jun Nie <[email protected]> [150616 18:58]: > >> >>> >> + if (pcs->bits_per_mux) { > >> >>> >> + int pin_pos, byte_num, num_pins_in_register; > >> >>> >> + > >> >>> >> + num_pins_in_register = pcs->width / > >> >>> >> pcs->bits_per_pin; > >> >>> >> + byte_num = (pcs->bits_per_pin * pin) / > >> >>> >> BITS_PER_BYTE; > >> >>> >> + offset = (byte_num / mux_bytes) * mux_bytes; > >> >>> >> + pin_pos = pin % num_pins_in_register; > >> >>> >> + pin_pos *= pcs->bits_per_pin; > >> >>> >> + data = pcs->read(pcs->base + offset) & > >> >>> >> + ~(pcs->fmask << pin_pos); > >> >>> > > >> >>> > Should you check the pcs->fmask here too in case some bits are > >> >>> > reserved? > >> >>> > > >> >>> Did not catch your idea? Those bits set in fmask are dedicated for one > >> >>> pin mux control and should be clear before set as desired value per my > >> >>> understanding. Do you mean some bits may be reserved and not for any > >> >>> function? > >> >> > >> >> Right, can you please check that we don't try to write to reserved > >> >> bits in the hardawre if the mask is set? > >> > >> > Then I have question that how can I know what bits is for function > >> > mask, what bits are for reserved? Do we have any other value to > >> > indicate it? I did not find it in one register for one pin mux case. > >> > >> Could you help elaborate this? Thanks! > > > > We can only write to the bits specified in pinctrl-single,function-mask. > > > I see, you want below mask to make sure gpiofunc value does not exceed > expected bits though it should be safe if dts data is correct. Right? > + data = pcs->read(pcs->base + offset) & > + ~(pcs->fmask << pin_pos); > + data |= (pcs->fmask & frange->gpiofunc) << pin_pos;
Yes please :) Tony -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
