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From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: lgirdwood@gmail.com,
	broonie@kernel.org,
	=?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>,
	linux-pwm@vger.kernel.org,
	linux-amlogic@lists.infradead.org
Cc: linux-kernel@vger.kernel.org,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Dmitry Rokosov <ddrokosov@sberdevices.ru>,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Subject: [RFC PATCH v2 1/3] regulator: pwm-regulator: Add validity checks in continuous .get_voltage
Date: Sat, 13 Jan 2024 23:46:26 +0100
Message-ID: <20240113224628.377993-2-martin.blumenstingl@googlemail.com>
In-Reply-To: <20240113224628.377993-1-martin.blumenstingl@googlemail.com>
References: <20240113224628.377993-1-martin.blumenstingl@googlemail.com>
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Continuous regulators can be configured to operate only in a certain
duty cycle range (for example from 0..91%). Add a check to error out if
the duty cycle translates to an unsupported (or out of range) voltage.

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
Changes from v1 -> v2:
- this patch is new, using suggestions from Uwe


 drivers/regulator/pwm-regulator.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 698c420e0869..226ca4c62673 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -158,6 +158,9 @@ static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
 	pwm_get_state(drvdata->pwm, &pstate);
 
 	voltage = pwm_get_relative_duty_cycle(&pstate, duty_unit);
+	if (voltage < min(max_uV_duty, min_uV_duty) ||
+	    voltage > max(max_uV_duty, min_uV_duty))
+		return -ENOTRECOVERABLE;
 
 	/*
 	 * The dutycycle for min_uV might be greater than the one for max_uV.
-- 
2.43.0