Merge branch 'for-4.11/drivers' into for-next

drivers/pwm/pwm-pca9685.c

@@ -20,8 +20,10 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/gpio/driver.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/pwm.h>
@@ -65,7 +67,6 @@
 #define PCA9685_MAXCHAN		0x10
 
 #define LED_FULL		(1 << 4)
-#define MODE1_RESTART		(1 << 7)
 #define MODE1_SLEEP		(1 << 4)
 #define MODE2_INVRT		(1 << 4)
 #define MODE2_OUTDRV		(1 << 2)
@@ -81,6 +82,10 @@ struct pca9685 {
 	int active_cnt;
 	int duty_ns;
 	int period_ns;
+#if IS_ENABLED(CONFIG_GPIOLIB)
+	struct mutex lock;
+	struct gpio_chip gpio;
+#endif
 };
 
 static inline struct pca9685 *to_pca(struct pwm_chip *chip)
@@ -88,6 +93,151 @@ static inline struct pca9685 *to_pca(struct pwm_chip *chip)
 	return container_of(chip, struct pca9685, chip);
 }
 
+#if IS_ENABLED(CONFIG_GPIOLIB)
+static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm;
+
+	mutex_lock(&pca->lock);
+
+	pwm = &pca->chip.pwms[offset];
+
+	if (pwm->flags & (PWMF_REQUESTED | PWMF_EXPORTED)) {
+		mutex_unlock(&pca->lock);
+		return -EBUSY;
+	}
+
+	pwm_set_chip_data(pwm, (void *)1);
+
+	mutex_unlock(&pca->lock);
+	return 0;
+}
+
+static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm;
+
+	mutex_lock(&pca->lock);
+	pwm = &pca->chip.pwms[offset];
+	pwm_set_chip_data(pwm, NULL);
+	mutex_unlock(&pca->lock);
+}
+
+static bool pca9685_pwm_is_gpio(struct pca9685 *pca, struct pwm_device *pwm)
+{
+	bool is_gpio = false;
+
+	mutex_lock(&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;
+	}
+
+	mutex_unlock(&pca->lock);
+	return is_gpio;
+}
+
+static int pca9685_pwm_gpio_get(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm = &pca->chip.pwms[offset];
+	unsigned int value;
+
+	regmap_read(pca->regmap, LED_N_ON_H(pwm->hwpwm), &value);
+
+	return value & LED_FULL;
+}
+
+static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset,
+				 int value)
+{
+	struct pca9685 *pca = gpiochip_get_data(gpio);
+	struct pwm_device *pwm = &pca->chip.pwms[offset];
+	unsigned int on = value ? LED_FULL : 0;
+
+	/* Clear both OFF registers */
+	regmap_write(pca->regmap, LED_N_OFF_L(pwm->hwpwm), 0);
+	regmap_write(pca->regmap, LED_N_OFF_H(pwm->hwpwm), 0);
+
+	/* Set the full ON bit */
+	regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on);
+}
+
+static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip,
+					  unsigned int offset)
+{
+	/* Always out */
+	return 0;
+}
+
+static int pca9685_pwm_gpio_direction_input(struct gpio_chip *gpio,
+					    unsigned int offset)
+{
+	return -EINVAL;
+}
+
+static int pca9685_pwm_gpio_direction_output(struct gpio_chip *gpio,
+					     unsigned int offset, int value)
+{
+	pca9685_pwm_gpio_set(gpio, offset, value);
+
+	return 0;
+}
+
+/*
+ * The PCA9685 has a bit for turning the PWM output full off or on. Some
+ * boards like Intel Galileo actually uses these as normal GPIOs so we
+ * expose a GPIO chip here which can exclusively take over the underlying
+ * PWM channel.
+ */
+static int pca9685_pwm_gpio_probe(struct pca9685 *pca)
+{
+	struct device *dev = pca->chip.dev;
+
+	mutex_init(&pca->lock);
+
+	pca->gpio.label = dev_name(dev);
+	pca->gpio.parent = dev;
+	pca->gpio.request = pca9685_pwm_gpio_request;
+	pca->gpio.free = pca9685_pwm_gpio_free;
+	pca->gpio.get_direction = pca9685_pwm_gpio_get_direction;
+	pca->gpio.direction_input = pca9685_pwm_gpio_direction_input;
+	pca->gpio.direction_output = pca9685_pwm_gpio_direction_output;
+	pca->gpio.get = pca9685_pwm_gpio_get;
+	pca->gpio.set = pca9685_pwm_gpio_set;
+	pca->gpio.base = -1;
+	pca->gpio.ngpio = PCA9685_MAXCHAN;
+	pca->gpio.can_sleep = true;
+
+	return devm_gpiochip_add_data(dev, &pca->gpio, pca);
+}
+#else
+static inline bool pca9685_pwm_is_gpio(struct pca9685 *pca,
+				       struct pwm_device *pwm)
+{
+	return false;
+}
+
+static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca)
+{
+	return 0;
+}
+#endif
+
 static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			      int duty_ns, int period_ns)
 {
@@ -117,16 +267,6 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			udelay(500);
 
 			pca->period_ns = period_ns;
-
-			/*
-			 * If the duty cycle did not change, restart PWM with
-			 * the same duty cycle to period ratio and return.
-			 */
-			if (duty_ns == pca->duty_ns) {
-				regmap_update_bits(pca->regmap, PCA9685_MODE1,
-						   MODE1_RESTART, 0x1);
-				return 0;
-			}
 		} else {
 			dev_err(chip->dev,
 				"prescaler not set: period out of bounds!\n");
@@ -264,6 +404,9 @@ 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))
+		return -EBUSY;
+
 	if (pca->active_cnt++ == 0)
 		return regmap_update_bits(pca->regmap, PCA9685_MODE1,
 					  MODE1_SLEEP, 0x0);
@@ -344,7 +487,15 @@ static int pca9685_pwm_probe(struct i2c_client *client,
 	pca->chip.dev = &client->dev;
 	pca->chip.base = -1;
 
-	return pwmchip_add(&pca->chip);
+	ret = pwmchip_add(&pca->chip);
+	if (ret < 0)
+		return ret;
+
+	ret = pca9685_pwm_gpio_probe(pca);
+	if (ret < 0)
+		pwmchip_remove(&pca->chip);
+
+	return ret;
 }
 
 static int pca9685_pwm_remove(struct i2c_client *client)