linux-kernel - [PATCH v3] pwm: tiehrpwm: Enable EHRPWM controller before setting configuration

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Message-ID: <20260120091922.71947-1-g-praveen@ti.com>
Date: Tue, 20 Jan 2026 14:49:22 +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 v3] 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>
---
v3 <==> v2
==========
* Simplified the logic by adding guard function for runtime power 
  management.

v2 <==> v1
==========
* Removed space between Fixes and Signed-off tag

 drivers/pwm/pwm-tiehrpwm.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index 7a86cb090f76..2533c95b0ba9 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -237,8 +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);
 
@@ -290,8 +288,6 @@ 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;
 }
 
@@ -378,6 +374,8 @@ static int ehrpwm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	int err;
 	bool enabled = pwm->state.enabled;
 
+	guard(pm_runtime_active)(pwmchip_parent(chip));
+
 	if (state->polarity != pwm->state.polarity) {
 		if (enabled) {
 			ehrpwm_pwm_disable(chip, pwm);
-- 
2.34.1