linux-kernel - [RFC PATCH v2 2/3] regulator: pwm-regulator: Calculate the output voltage for disabled PWMs

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Date: Sat, 13 Jan 2024 23:46:27 +0100
From: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
To: lgirdwood@...il.com,
	broonie@...nel.org,
	Uwe Kleine-König <u.kleine-koenig@...gutronix.de>,
	linux-pwm@...r.kernel.org,
	linux-amlogic@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org,
	Heiner Kallweit <hkallweit1@...il.com>,
	Dmitry Rokosov <ddrokosov@...rdevices.ru>,
	Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Subject: [RFC PATCH v2 2/3] regulator: pwm-regulator: Calculate the output voltage for disabled PWMs

If a PWM output is disabled then it's voltage has to be calculated
based on a zero duty cycle (for normal polarity) or duty cycle being
equal to the PWM period (for inverted polarity). Add support for this
to pwm_regulator_get_voltage().

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
---
Changes from v1 -> v2:
- update pstate.duty_cycle to catch out-of-range values with the new
  check from the first patch in this series


 drivers/regulator/pwm-regulator.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 226ca4c62673..d27b9a7a30c9 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -157,6 +157,13 @@ static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
 
 	pwm_get_state(drvdata->pwm, &pstate);
 
+	if (!pstate.enabled) {
+		if (pstate.polarity == PWM_POLARITY_INVERSED)
+			pstate.duty_cycle = pstate.period;
+		else
+			pstate.duty_cycle = 0;
+	}
+
 	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))
-- 
2.43.0