linux-kernel - [PATCH v2] pinctrl: tegra: Set SFIO mode to Mux Register

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20250306050542.16335-1-pshete@nvidia.com>
Date: Thu, 6 Mar 2025 10:35:42 +0530
From: Prathamesh Shete <pshete@...dia.com>
To: <linus.walleij@...aro.org>, <thierry.reding@...il.com>,
	<jonathanh@...dia.com>, <linux-gpio@...r.kernel.org>,
	<linux-tegra@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: <pshete@...dia.com>
Subject: [PATCH v2] pinctrl: tegra: Set SFIO mode to Mux Register

Tegra devices have an 'sfsel' bit field that determines whether a pin
operates in SFIO (Special Function I/O) or GPIO mode. Currently,
tegra_pinctrl_gpio_disable_free() sets this bit when releasing a GPIO.

However, tegra_pinctrl_set_mux() can be called independently in certain
code paths where gpio_disable_free() is not invoked. In such cases, failing
to set the SFIO mode could lead to incorrect pin configurations, resulting
in functional issues for peripherals relying on SFIO.

This patch ensures that whenever set_mux() is called, the SFIO mode is
correctly set in the Mux Register if the 'sfsel' bit is present. This
prevents situations where the pin remains in GPIO mode despite being
configured for SFIO use.

Fixes: 59b67585e242 ("pinctrl: add a driver for NVIDIA Tegra")
Signed-off-by: Prathamesh Shete <pshete@...dia.com>
---
v1->v2: Updated commit message describing the need.
v1: https://lore.kernel.org/linux-tegra/CACRpkdY2E+8quTVVkCqoph-h6Ye+hEb+z+D5+2g=ArmfLpGR1A@mail.gmail.com/

 drivers/pinctrl/tegra/pinctrl-tegra.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c b/drivers/pinctrl/tegra/pinctrl-tegra.c
index abe31fead395..27823e420734 100644
--- a/drivers/pinctrl/tegra/pinctrl-tegra.c
+++ b/drivers/pinctrl/tegra/pinctrl-tegra.c
@@ -270,6 +270,9 @@ static int tegra_pinctrl_set_mux(struct pinctrl_dev *pctldev,
 	val = pmx_readl(pmx, g->mux_bank, g->mux_reg);
 	val &= ~(0x3 << g->mux_bit);
 	val |= i << g->mux_bit;
+	/* Set the SFIO/GPIO selection to SFIO when under pinmux control*/
+	if (pmx->soc->sfsel_in_mux)
+		val |= (1 << g->sfsel_bit);
 	pmx_writel(pmx, val, g->mux_bank, g->mux_reg);

 	return 0;
-- 
2.17.1