On 02/20/2018 06:56 AM, Andy Shevchenko wrote:

On Mon, Feb 19, 2018 at 11:57 PM, David Lechner [off-list ref] wrote:

quoted

This fixes pcs_request_gpio() in the pinctrl-single driver when
bits_per_mux != 0. It appears this was overlooked when the multiple
pins per register feature was added.

Fixes: 4e7e8017a80e ("pinctrl: pinctrl-single: enhance to configure multiple pins of different modules")
Signed-off-by: David Lechner <david@lechnology.com>
---

v2 changes:
- don't wrap Fixes: line in commit message since it is a special machine-
   readable line.

There was some discussion in v1 about using DIV_ROUND_UP(), etc. macros, but
the consensus was to leave it as-is since it matches existing code and that
macros can be introduced in another patch.

  drivers/pinctrl/pinctrl-single.c | 22 +++++++++++++++++++---
  1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index cec7537..a7c5eb3 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c

@@ -391,9 +391,25 @@ static int pcs_request_gpio(struct pinctrl_dev *pctldev,
                         || pin < frange->offset)
                         continue;

quoted

                 mux_bytes = pcs->width / BITS_PER_BYTE;
-               data = pcs->read(pcs->base + pin * mux_bytes) & ~pcs->fmask;
-               data |= frange->gpiofunc;
-               pcs->write(data, pcs->base + pin * mux_bytes);
+
+               if (pcs->bits_per_mux) {
+                       int byte_num, offset, pin_shift;
+
+                       byte_num = (pcs->bits_per_pin * pin) / BITS_PER_BYTE;
+                       offset = (byte_num / mux_bytes) * mux_bytes;
+                       pin_shift = pin % (pcs->width / pcs->bits_per_pin) *
+                                   pcs->bits_per_pin;
+
+                       data = pcs->read(pcs->base + offset);
+                       data &= ~(pcs->fmask << pin_shift);
+                       data |= frange->gpiofunc << pin_shift;
+                       pcs->write(data, pcs->base + offset);
+               } else {

quoted

+                       data = pcs->read(pcs->base + pin * mux_bytes);
+                       data &= ~pcs->fmask;
+                       data |= frange->gpiofunc;
+                       pcs->write(data, pcs->base + pin * mux_bytes);

Just an idea, you may leave this almost untouched and do calculate
pin_shift and offset in condition, like

if (...) {
  pin_shift = ...
  offset = ...
} else {
  pin_shift = 0;
  offset = pin * mux_bytes;
}

                        data = pcs->read(pcs->base + offset);
                        data &= ~(pcs->fmask << pin_shift);
                        data |= frange->gpiofunc << pin_shift;
                        pcs->write(data, pcs->base + offset);

It's also possible to split to two changes, where first introduces
that variables and their default values (see 'else' branch) and second
one introduces an if branch override.

quoted

+               }
                 break;

Yes, there are many ways this could be done. However, I would like
to just leave it as it is since it matches the patterns used
elsewhere in this file.