linux-kernel - [PATCH AUTOSEL 5.15 2/5] pinctrl: meson: define the pull up/down resistor value as 60 kOhm

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Message-Id: <20250506213734.2983663-2-sashal@kernel.org>
Date: Tue,  6 May 2025 17:37:31 -0400
From: Sasha Levin <sashal@...nel.org>
To: patches@...ts.linux.dev,
	stable@...r.kernel.org
Cc: Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Sasha Levin <sashal@...nel.org>,
	khilman@...libre.com,
	linux-gpio@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-amlogic@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH AUTOSEL 5.15 2/5] pinctrl: meson: define the pull up/down resistor value as 60 kOhm

From: Martin Blumenstingl <martin.blumenstingl@...glemail.com>

[ Upstream commit e56088a13708757da68ad035269d69b93ac8c389 ]

The public datasheets of the following Amlogic SoCs describe a typical
resistor value for the built-in pull up/down resistor:
- Meson8/8b/8m2: not documented
- GXBB (S905): 60 kOhm
- GXL (S905X): 60 kOhm
- GXM (S912): 60 kOhm
- G12B (S922X): 60 kOhm
- SM1 (S905D3): 60 kOhm

The public G12B and SM1 datasheets additionally state min and max
values:
- min value: 50 kOhm for both, pull-up and pull-down
- max value for the pull-up: 70 kOhm
- max value for the pull-down: 130 kOhm

Use 60 kOhm in the pinctrl-meson driver as well so it's shown in the
debugfs output. It may not be accurate for Meson8/8b/8m2 but in reality
60 kOhm is closer to the actual value than 1 Ohm.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@...aro.org>
Link: https://lore.kernel.org/20250329190132.855196-1-martin.blumenstingl@googlemail.com
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/pinctrl/meson/pinctrl-meson.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c
index 49851444a6e3b..d239ad85a510d 100644
--- a/drivers/pinctrl/meson/pinctrl-meson.c
+++ b/drivers/pinctrl/meson/pinctrl-meson.c
@@ -486,7 +486,7 @@ static int meson_pinconf_get(struct pinctrl_dev *pcdev, unsigned int pin,
 	case PIN_CONFIG_BIAS_PULL_DOWN:
 	case PIN_CONFIG_BIAS_PULL_UP:
 		if (meson_pinconf_get_pull(pc, pin) == param)
-			arg = 1;
+			arg = 60000;
 		else
 			return -EINVAL;
 		break;
-- 
2.39.5