*/
#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>
#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)
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)
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)
{
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");
{
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);
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)
projects / karo-tx-linux.git / blobdiff