1 files changed, 48 insertions, 41 deletions

diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 168684b02ebc..590375be5214 100644
--- a/drivers/pwm/pwm-pca9685.c
+++ b/drivers/pwm/pwm-pca9685.c
@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/pm_runtime.h>
+#include <linux/bitmap.h>
 
 /*
  * Because the PCA9685 has only one prescaler per chip, changing the period of
@@ -74,6 +75,7 @@ struct pca9685 {
 #if IS_ENABLED(CONFIG_GPIOLIB)
 	struct mutex lock;
 	struct gpio_chip gpio;
+	DECLARE_BITMAP(pwms_inuse, PCA9685_MAXCHAN + 1);
 #endif
 };
 
@@ -83,51 +85,51 @@ static inline struct pca9685 *to_pca(struct pwm_chip *chip)
 }
 
 #if IS_ENABLED(CONFIG_GPIOLIB)
-static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
+static bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca, int pwm_idx)
 {
-	struct pca9685 *pca = gpiochip_get_data(gpio);
-	struct pwm_device *pwm;
+	bool is_inuse;
 
 	mutex_lock(&pca->lock);
-
-	pwm = &pca->chip.pwms[offset];
-
-	if (pwm->flags & (PWMF_REQUESTED | PWMF_EXPORTED)) {
-		mutex_unlock(&pca->lock);
-		return -EBUSY;
+	if (pwm_idx >= PCA9685_MAXCHAN) {
+		/*
+		 * "all LEDs" channel:
+		 * pretend already in use if any of the PWMs are requested
+		 */
+		if (!bitmap_empty(pca->pwms_inuse, PCA9685_MAXCHAN)) {
+			is_inuse = true;
+			goto out;
+		}
+	} else {
+		/*
+		 * regular channel:
+		 * pretend already in use if the "all LEDs" channel is requested
+		 */
+		if (test_bit(PCA9685_MAXCHAN, pca->pwms_inuse)) {
+			is_inuse = true;
+			goto out;
+		}
 	}
-
-	pwm_set_chip_data(pwm, (void *)1);
-
+	is_inuse = test_and_set_bit(pwm_idx, pca->pwms_inuse);
+out:
 	mutex_unlock(&pca->lock);
-	pm_runtime_get_sync(pca->chip.dev);
-	return 0;
+	return is_inuse;
 }
 
-static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
+static void pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
 {
-	bool is_gpio = false;
-
 	mutex_lock(&pca->lock);
+	clear_bit(pwm_idx, pca->pwms_inuse);
+	mutex_unlock(&pca->lock);
+}
 
-	if (pwm->hwpwm >= PCA9685_MAXCHAN) {
-		unsigned int i;
-
-		/*
-		 * Check if any of the GPIOs are requested and in that case
-		 * prevent using the "all LEDs" channel.
-		 */
-		for (i = 0; i < pca->gpio.ngpio; i++)
-			if (gpiochip_is_requested(&pca->gpio, i)) {
-				is_gpio = true;
-				break;
-			}
-	} else if (pwm_get_chip_data(pwm)) {
-		is_gpio = true;
-	}
+static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
 
-	mutex_unlock(&pca->lock);
-	return is_gpio;
+	if (pca9685_pwm_test_and_set_inuse(pca, offset))
+		return -EBUSY;
+	pm_runtime_get_sync(pca->chip.dev);
+	return 0;
 }
 
 static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
@@ -159,13 +161,10 @@ static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
 static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
 {
 	struct pca9685 *pca = gpiochip_get_data(gpio);
-	struct pwm_device *pwm;
 
 	pca9685_pwm_gpio_set(gpio, offset, 0);
 	pm_runtime_put(pca->chip.dev);
-	mutex_lock(&pca->lock);
-	pwm = &pca->chip.pwms[offset];
-	mutex_unlock(&pca->lock);
+	pca9685_pwm_clear_inuse(pca, offset);
 }
 
 static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
@@ -217,12 +216,17 @@ static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
 	return devm_gpiochip_add_data(dev, &pca->gpio, pca);
 }
 #else
-static inline bool pca9685_pwm_is_gpio(struct pca9685 *pca,
-				       struct pwm_device *pwm)
+static inline bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca,
+						  int pwm_idx)
 {
 	return false;
 }
 
+static inline void
+pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx)
+{
+}
+
 static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
 {
 	return 0;
@@ -406,7 +410,7 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
 	struct pca9685 *pca = to_pca(chip);
 
-	if (pca9685_pwm_is_gpio(pca, pwm))
+	if (pca9685_pwm_test_and_set_inuse(pca, pwm->hwpwm))
 		return -EBUSY;
 	pm_runtime_get_sync(chip->dev);
 
@@ -415,8 +419,11 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 
 static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
+	struct pca9685 *pca = to_pca(chip);
+
 	pca9685_pwm_disable(chip, pwm);
 	pm_runtime_put(chip->dev);
+	pca9685_pwm_clear_inuse(pca, pwm->hwpwm);
 }
 
 static const struct pwm_ops pca9685_pwm_ops = {