pwm: lpc18xx-sct: Drop driver local locking

Both mutexes are only used in one function each. These functions are only
called by the .apply() callback. As the .apply() calls are serialized by
the core since commit 1cc2e1f ("pwm: Add more locking") the mutexes
have no effect apart from runtime overhead. Drop them.

Signed-off-by: Uwe Kleine-König <[email protected]>
Reviewed-by: Vladimir Zapolskiy <[email protected]>
Link: https://lore.kernel.org/r/4f7a2da37adbfe4743564245119045826d86eca6.1750788649.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <[email protected]>

Author: ukleinek

drivers/pwm/pwm-lpc18xx-sct.c

@@ -100,8 +100,6 @@ struct lpc18xx_pwm_chip {
 	u64 max_period_ns;
 	unsigned int period_event;
 	unsigned long event_map;
-	struct mutex res_lock;
-	struct mutex period_lock;
 	struct lpc18xx_pwm_data channeldata[LPC18XX_NUM_PWMS];
 };
 
@@ -129,8 +127,6 @@ static void lpc18xx_pwm_set_conflict_res(struct lpc18xx_pwm_chip *lpc18xx_pwm,
 {
 	u32 val;
 
-	mutex_lock(&lpc18xx_pwm->res_lock);
-
 	/*
 	 * Simultaneous set and clear may happen on an output, that is the case
 	 * when duty_ns == period_ns. LPC18xx SCT allows to set a conflict
@@ -140,8 +136,6 @@ static void lpc18xx_pwm_set_conflict_res(struct lpc18xx_pwm_chip *lpc18xx_pwm,
 	val &= ~LPC18XX_PWM_RES_MASK(pwm->hwpwm);
 	val |= LPC18XX_PWM_RES(pwm->hwpwm, action);
 	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_RES_BASE, val);
-
-	mutex_unlock(&lpc18xx_pwm->res_lock);
 }
 
 static void lpc18xx_pwm_config_period(struct pwm_chip *chip, u64 period_ns)
@@ -200,8 +194,6 @@ static int lpc18xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return -ERANGE;
 	}
 
-	mutex_lock(&lpc18xx_pwm->period_lock);
-
 	requested_events = bitmap_weight(&lpc18xx_pwm->event_map,
 					 LPC18XX_PWM_EVENT_MAX);
 
@@ -214,7 +206,6 @@ static int lpc18xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	    lpc18xx_pwm->period_ns) {
 		dev_err(pwmchip_parent(chip), "conflicting period requested for PWM %u\n",
 			pwm->hwpwm);
-		mutex_unlock(&lpc18xx_pwm->period_lock);
 		return -EBUSY;
 	}
 
@@ -224,8 +215,6 @@ static int lpc18xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		lpc18xx_pwm_config_period(chip, period_ns);
 	}
 
-	mutex_unlock(&lpc18xx_pwm->period_lock);
-
 	lpc18xx_pwm_config_duty(chip, pwm, duty_ns);
 
 	return 0;
@@ -377,9 +366,6 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 	if (lpc18xx_pwm->clk_rate > NSEC_PER_SEC)
 		return dev_err_probe(&pdev->dev, -EINVAL, "pwm clock to fast\n");
 
-	mutex_init(&lpc18xx_pwm->res_lock);
-	mutex_init(&lpc18xx_pwm->period_lock);
-
 	lpc18xx_pwm->max_period_ns =
 		mul_u64_u64_div_u64(NSEC_PER_SEC, LPC18XX_PWM_TIMER_MAX, lpc18xx_pwm->clk_rate);