linux-kernel - [PATCH v2] pwm: tiehrpwm: Enable EHRPWM controller before setting configuration

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Message-ID: <20260107055339.10999-1-g-praveen@ti.com>
Date: Wed, 7 Jan 2026 11:23:39 +0530
From: Gokul Praveen <g-praveen@...com>
To: <j-keerthy@...com>, <ukleinek@...nel.org>, <linux-pwm@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: <g-praveen@...com>, <u-kumar1@...com>, <n-francis@...com>
Subject: [PATCH v2] pwm: tiehrpwm: Enable EHRPWM controller before setting configuration

The period and duty cycle configurations does not get reflected
after setting them using sysfs nodes. This is because at the
end of ehrpwm_pwm_config function, the put_sync function is
called which resets the hardware.

Fix it by preventing the pwm controller from going into
low-power mode.

Fixes: 5f027d9b83db("pwm: tiehrpwm: Implement .apply() callback")
Signed-off-by: Gokul Praveen <g-praveen@...com>
---
v2 <==> v1
==========
* Removed space between Fixes and Signed-off tag

 drivers/pwm/pwm-tiehrpwm.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index 7a86cb090f76..408aed70be8c 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -237,7 +237,6 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (period_cycles < 1)
 		period_cycles = 1;
 
-	pm_runtime_get_sync(pwmchip_parent(chip));
 
 	/* Update clock prescaler values */
 	ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
@@ -290,12 +289,11 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (!(duty_cycles > period_cycles))
 		ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
 
-	pm_runtime_put_sync(pwmchip_parent(chip));
-
 	return 0;
 }
 
-static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm,
+				const struct pwm_state *state)
 {
 	struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
 	u16 aqcsfrc_val, aqcsfrc_mask;
@@ -304,6 +302,13 @@ static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 	/* Leave clock enabled on enabling PWM */
 	pm_runtime_get_sync(pwmchip_parent(chip));
 
+	ret = ehrpwm_pwm_config(chip, pwm, state->duty_cycle, state->period, state->polarity);
+
+	if (ret) {
+		pm_runtime_put_sync(pwmchip_parent(chip));
+		return ret;
+	}
+
 	/* Disabling Action Qualifier on PWM output */
 	if (pwm->hwpwm) {
 		aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
@@ -391,12 +396,11 @@ static int ehrpwm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 		return 0;
 	}
 
-	err = ehrpwm_pwm_config(chip, pwm, state->duty_cycle, state->period, state->polarity);
-	if (err)
-		return err;
-
 	if (!enabled)
-		err = ehrpwm_pwm_enable(chip, pwm);
+		err = ehrpwm_pwm_enable(chip, pwm, state);
+	else
+		err = ehrpwm_pwm_config(chip, pwm, state->duty_cycle,
+					state->period, state->polarity);
 
 	return err;
 }
-- 
2.34.1