[PATCH 3.16 055/366] pinctrl: pinctrl-single: Fix pcs_request_gpio() when bits_per_mux != 0

[Ben Hutchings]

3.16.60-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: David Lechner <da...@lechnology.com>

commit 45dcb54f014d3d1f5cc3919b5f0c97087d7cb3dd upstream.

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 <da...@lechnology.com>
Acked-by: Tony Lindgren <t...@atomide.com>
Signed-off-by: Linus Walleij <linus.wall...@linaro.org>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/pinctrl/pinctrl-single.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -562,9 +562,25 @@ static int pcs_request_gpio(struct pinct
                        || pin < frange->offset)
                        continue;
                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 {
+                       data = pcs->read(pcs->base + pin * mux_bytes);
+                       data &= ~pcs->fmask;
+                       data |= frange->gpiofunc;
+                       pcs->write(data, pcs->base + pin * mux_bytes);
+               }
                break;
        }
        return 0;