[PATCH 6.6 470/638] gpio: nomadik: fix offset bug in nmk_pmx_set()

[Sasha Levin]

From: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>

[ Upstream commit 53cf6b72e074864b94ade97dcb6f30b5ac1a82dc ]

Previously, the statement looked like:

    slpm[x] &= ~BIT(g->grp.pins[i]);

Where:
 - slpm is a unsigned int pointer;
 - g->grp.pins[i] is a pin number. It can grow to more than 32.

The expected shift amount is a pin bank offset.

This bug does not occur on every group or pin: the altsetting must be
NMK_GPIO_ALT_C and the pin must be 32 or above. It might have occured.
For example, in pinctrl-nomadik-db8500.c, pin group i2c3_c_2 has the
right altsetting and pins 229 and 230.

Fixes: dbfe8ca259e1 ("pinctrl/nomadik: implement pin multiplexing")
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240228-mbly-gpio-v2-5-3ba757474006@xxxxxxxxxxx
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/pinctrl/nomadik/pinctrl-nomadik.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/nomadik/pinctrl-nomadik.c b/drivers/pinctrl/nomadik/pinctrl-nomadik.c
index 86a638077a697..e7d33093994b2 100644
--- a/drivers/pinctrl/nomadik/pinctrl-nomadik.c
+++ b/drivers/pinctrl/nomadik/pinctrl-nomadik.c
@@ -1573,8 +1573,10 @@ static int nmk_pmx_set(struct pinctrl_dev *pctldev, unsigned function,
 		 * Then mask the pins that need to be sleeping now when we're
 		 * switching to the ALT C function.
 		 */
-		for (i = 0; i < g->grp.npins; i++)
-			slpm[g->grp.pins[i] / NMK_GPIO_PER_CHIP] &= ~BIT(g->grp.pins[i]);
+		for (i = 0; i < g->grp.npins; i++) {
+			unsigned int bit = g->grp.pins[i] % NMK_GPIO_PER_CHIP;
+			slpm[g->grp.pins[i] / NMK_GPIO_PER_CHIP] &= ~BIT(bit);
+		}
 		nmk_gpio_glitch_slpm_init(slpm);
 	}
 
-- 
2.43.0