diff options
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/pwm-pca9685.c | 112 |
1 files changed, 79 insertions, 33 deletions
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 0cfb3571a732..5f55cfab9b1c 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -30,6 +30,7 @@ #include <linux/regmap.h> #include <linux/slab.h> #include <linux/delay.h> +#include <linux/pm_runtime.h> /* * Because the PCA9685 has only one prescaler per chip, changing the period of @@ -79,7 +80,6 @@ struct pca9685 { struct pwm_chip chip; struct regmap *regmap; - int active_cnt; int duty_ns; int period_ns; #if IS_ENABLED(CONFIG_GPIOLIB) @@ -111,20 +111,10 @@ static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset) pwm_set_chip_data(pwm, (void *)1); mutex_unlock(&pca->lock); + pm_runtime_get_sync(pca->chip.dev); 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; @@ -177,6 +167,19 @@ static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset, regmap_write(pca->regmap, LED_N_ON_H(pwm->hwpwm), on); } +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]; + pwm_set_chip_data(pwm, NULL); + mutex_unlock(&pca->lock); +} + static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip, unsigned int offset) { @@ -238,6 +241,16 @@ static inline int pca9685_pwm_gpio_probe(struct pca9685 *pca) } #endif +static void pca9685_set_sleep_mode(struct pca9685 *pca, int sleep) +{ + regmap_update_bits(pca->regmap, PCA9685_MODE1, + MODE1_SLEEP, sleep ? MODE1_SLEEP : 0); + if (!sleep) { + /* Wait 500us for the oscillator to be back up */ + udelay(500); + } +} + static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { @@ -252,19 +265,20 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, if (prescale >= PCA9685_PRESCALE_MIN && prescale <= PCA9685_PRESCALE_MAX) { + /* + * putting the chip briefly into SLEEP mode + * at this point won't interfere with the + * pm_runtime framework, because the pm_runtime + * state is guaranteed active here. + */ /* Put chip into sleep mode */ - regmap_update_bits(pca->regmap, PCA9685_MODE1, - MODE1_SLEEP, MODE1_SLEEP); + pca9685_set_sleep_mode(pca, 1); /* Change the chip-wide output frequency */ regmap_write(pca->regmap, PCA9685_PRESCALE, prescale); /* Wake the chip up */ - regmap_update_bits(pca->regmap, PCA9685_MODE1, - MODE1_SLEEP, 0x0); - - /* Wait 500us for the oscillator to be back up */ - udelay(500); + pca9685_set_sleep_mode(pca, 0); pca->period_ns = period_ns; } else { @@ -406,21 +420,15 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) 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); + pm_runtime_get_sync(chip->dev); return 0; } static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) { - struct pca9685 *pca = to_pca(chip); - - if (--pca->active_cnt == 0) - regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, - MODE1_SLEEP); + pca9685_pwm_disable(chip, pwm); + pm_runtime_put(chip->dev); } static const struct pwm_ops pca9685_pwm_ops = { @@ -492,22 +500,54 @@ static int pca9685_pwm_probe(struct i2c_client *client, return ret; ret = pca9685_pwm_gpio_probe(pca); - if (ret < 0) + if (ret < 0) { pwmchip_remove(&pca->chip); + return ret; + } + + /* the chip comes out of power-up in the active state */ + pm_runtime_set_active(&client->dev); + /* + * enable will put the chip into suspend, which is what we + * want as all outputs are disabled at this point + */ + pm_runtime_enable(&client->dev); - return ret; + return 0; } static int pca9685_pwm_remove(struct i2c_client *client) { struct pca9685 *pca = i2c_get_clientdata(client); + int ret; - regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, - MODE1_SLEEP); + ret = pwmchip_remove(&pca->chip); + if (ret) + return ret; + pm_runtime_disable(&client->dev); + return 0; +} - return pwmchip_remove(&pca->chip); +#ifdef CONFIG_PM +static int pca9685_pwm_runtime_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct pca9685 *pca = i2c_get_clientdata(client); + + pca9685_set_sleep_mode(pca, 1); + return 0; } +static int pca9685_pwm_runtime_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct pca9685 *pca = i2c_get_clientdata(client); + + pca9685_set_sleep_mode(pca, 0); + return 0; +} +#endif + static const struct i2c_device_id pca9685_id[] = { { "pca9685", 0 }, { /* sentinel */ }, @@ -530,11 +570,17 @@ static const struct of_device_id pca9685_dt_ids[] = { MODULE_DEVICE_TABLE(of, pca9685_dt_ids); #endif +static const struct dev_pm_ops pca9685_pwm_pm = { + SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend, + pca9685_pwm_runtime_resume, NULL) +}; + static struct i2c_driver pca9685_i2c_driver = { .driver = { .name = "pca9685-pwm", .acpi_match_table = ACPI_PTR(pca9685_acpi_ids), .of_match_table = of_match_ptr(pca9685_dt_ids), + .pm = &pca9685_pwm_pm, }, .probe = pca9685_pwm_probe, .remove = pca9685_pwm_remove, |