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From: =?utf-8?q?Th=C3=A9o_Lebrun?= <theo.lebrun@bootlin.com>
Date: Wed, 28 Feb 2024 12:28:03 +0100
Subject: [PATCH v2 05/30] gpio: nomadik: fix offset bug in nmk_pmx_set()
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Message-Id: <20240228-mbly-gpio-v2-5-3ba757474006@bootlin.com>
References: <20240228-mbly-gpio-v2-0-3ba757474006@bootlin.com>
In-Reply-To: <20240228-mbly-gpio-v2-0-3ba757474006@bootlin.com>
To: Linus Walleij <linus.walleij@linaro.org>, 
 Bartosz Golaszewski <brgl@bgdev.pl>, Rob Herring <robh+dt@kernel.org>, 
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, 
 Conor Dooley <conor+dt@kernel.org>, Philipp Zabel <p.zabel@pengutronix.de>, 
 Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, 
 linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, 
 linux-mips@vger.kernel.org, Gregory CLEMENT <gregory.clement@bootlin.com>, 
 Vladimir Kondratiev <vladimir.kondratiev@mobileye.com>, 
 Thomas Petazzoni <thomas.petazzoni@bootlin.com>, 
 Tawfik Bayouk <tawfik.bayouk@mobileye.com>, 
 =?utf-8?q?Th=C3=A9o_Lebrun?= <theo.lebrun@bootlin.com>

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@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
 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 7911353ac97d..4f7c4af4f93c 100644
--- a/drivers/pinctrl/nomadik/pinctrl-nomadik.c
+++ b/drivers/pinctrl/nomadik/pinctrl-nomadik.c
@@ -1579,8 +1579,10 @@ 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);
 	}
 

-- 
2.44.0