[PATCH 2/2] pwm: atmel-tcb: Simplify checking the companion output

Uwe Kleine-König u.kleine-koenig at baylibre.com
Tue Jul 9 03:18:06 PDT 2024


The two outputs provided by the supported hardware share some settings,
so access to the other PWM is required when one of them is configured.

Instead of an explicit if to deterimine the other PWM just use
hwpwm ^ 1. Further atcbpwm is never NULL, so drop the corresponding
check.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at baylibre.com>
---
 drivers/pwm/pwm-atmel-tcb.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
index aca11493239a..2feee3744b50 100644
--- a/drivers/pwm/pwm-atmel-tcb.c
+++ b/drivers/pwm/pwm-atmel-tcb.c
@@ -260,7 +260,8 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 {
 	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
 	struct atmel_tcb_pwm_device *tcbpwm = &tcbpwmc->pwms[pwm->hwpwm];
-	struct atmel_tcb_pwm_device *atcbpwm = NULL;
+	/* companion PWM sharing register values period and div */
+	struct atmel_tcb_pwm_device *atcbpwm = &tcbpwmc->pwms[pwm->hwpwm ^ 1];
 	int i = 0;
 	int slowclk = 0;
 	unsigned period;
@@ -305,11 +306,6 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	duty = div_u64(duty_ns, min);
 	period = div_u64(period_ns, min);
 
-	if (pwm->hwpwm == 0)
-		atcbpwm = &tcbpwmc->pwms[1];
-	else
-		atcbpwm = &tcbpwmc->pwms[0];
-
 	/*
 	 * PWM devices provided by the TCB driver are grouped by 2.
 	 * PWM devices in a given group must be configured with the
@@ -318,8 +314,7 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * We're checking the period value of the second PWM device
 	 * in this group before applying the new config.
 	 */
-	if ((atcbpwm && atcbpwm->duty > 0 &&
-			atcbpwm->duty != atcbpwm->period) &&
+	if ((atcbpwm->duty > 0 && atcbpwm->duty != atcbpwm->period) &&
 		(atcbpwm->div != i || atcbpwm->period != period)) {
 		dev_err(pwmchip_parent(chip),
 			"failed to configure period_ns: PWM group already configured with a different value\n");
-- 
2.43.0




More information about the linux-arm-kernel mailing list