1 files changed, 33 insertions, 52 deletions

diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 9d965ffe66d1..3444c56b4bed 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -85,7 +85,7 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,
 	unsigned long long on_time_div;
 	unsigned long c = lpwm->info->clk_rate, base_unit_range;
 	unsigned long long base_unit, freq = NSEC_PER_SEC;
-	u32 orig_ctrl, ctrl;
+	u32 ctrl;
 
 	do_div(freq, period_ns);
 
@@ -93,26 +93,25 @@ static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,
 	 * The equation is:
 	 * base_unit = round(base_unit_range * freq / c)
 	 */
-	base_unit_range = BIT(lpwm->info->base_unit_bits) - 1;
+	base_unit_range = BIT(lpwm->info->base_unit_bits);
 	freq *= base_unit_range;
 
 	base_unit = DIV_ROUND_CLOSEST_ULL(freq, c);
+	/* base_unit must not be 0 and we also want to avoid overflowing it */
+	base_unit = clamp_val(base_unit, 1, base_unit_range - 1);
 
 	on_time_div = 255ULL * duty_ns;
 	do_div(on_time_div, period_ns);
 	on_time_div = 255ULL - on_time_div;
 
-	orig_ctrl = ctrl = pwm_lpss_read(pwm);
+	ctrl = pwm_lpss_read(pwm);
 	ctrl &= ~PWM_ON_TIME_DIV_MASK;
-	ctrl &= ~(base_unit_range << PWM_BASE_UNIT_SHIFT);
-	base_unit &= base_unit_range;
+	ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT);
 	ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;
 	ctrl |= on_time_div;
 
-	if (orig_ctrl != ctrl) {
-		pwm_lpss_write(pwm, ctrl);
-		pwm_lpss_write(pwm, ctrl | PWM_SW_UPDATE);
-	}
+	pwm_lpss_write(pwm, ctrl);
+	pwm_lpss_write(pwm, ctrl | PWM_SW_UPDATE);
 }
 
 static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)
@@ -121,41 +120,47 @@ static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)
 		pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
 }
 
+static int pwm_lpss_prepare_enable(struct pwm_lpss_chip *lpwm,
+				   struct pwm_device *pwm,
+				   const struct pwm_state *state)
+{
+	int ret;
+
+	ret = pwm_lpss_is_updating(pwm);
+	if (ret)
+		return ret;
+
+	pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
+	pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
+	ret = pwm_lpss_wait_for_update(pwm);
+	if (ret)
+		return ret;
+
+	pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
+	return 0;
+}
+
 static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			  const struct pwm_state *state)
 {
 	struct pwm_lpss_chip *lpwm = to_lpwm(chip);
-	int ret;
+	int ret = 0;
 
 	if (state->enabled) {
 		if (!pwm_is_enabled(pwm)) {
 			pm_runtime_get_sync(chip->dev);
-			ret = pwm_lpss_is_updating(pwm);
-			if (ret) {
-				pm_runtime_put(chip->dev);
-				return ret;
-			}
-			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);
-			ret = pwm_lpss_wait_for_update(pwm);
-			if (ret) {
+			ret = pwm_lpss_prepare_enable(lpwm, pwm, state);
+			if (ret)
 				pm_runtime_put(chip->dev);
-				return ret;
-			}
-			pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);
 		} else {
-			ret = pwm_lpss_is_updating(pwm);
-			if (ret)
-				return ret;
-			pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);
-			return pwm_lpss_wait_for_update(pwm);
+			ret = pwm_lpss_prepare_enable(lpwm, pwm, state);
 		}
 	} else if (pwm_is_enabled(pwm)) {
 		pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
 		pm_runtime_put(chip->dev);
 	}
 
-	return 0;
+	return ret;
 }
 
 static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -255,30 +260,6 @@ int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
 }
 EXPORT_SYMBOL_GPL(pwm_lpss_remove);
 
-int pwm_lpss_suspend(struct device *dev)
-{
-	struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
-	int i;
-
-	for (i = 0; i < lpwm->info->npwm; i++)
-		lpwm->saved_ctrl[i] = readl(lpwm->regs + i * PWM_SIZE + PWM);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_lpss_suspend);
-
-int pwm_lpss_resume(struct device *dev)
-{
-	struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
-	int i;
-
-	for (i = 0; i < lpwm->info->npwm; i++)
-		writel(lpwm->saved_ctrl[i], lpwm->regs + i * PWM_SIZE + PWM);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_lpss_resume);
-
 MODULE_DESCRIPTION("PWM driver for Intel LPSS");
 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 MODULE_LICENSE("GPL v2");