// SPDX-License-Identifier: GPL-2.0-only /* * Driver for PCA9685 16-channel 12-bit PWM LED controller * * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de> * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com> * * based on the pwm-twl-led.c driver */ #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> #include <linux/regmap.h> #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 * one channel affects the period of all 16 PWM outputs! * However, the ratio between each configured duty cycle and the chip-wide * period remains constant, because the OFF time is set in proportion to the * counter range. */ #define PCA9685_MODE1 0x00 #define PCA9685_MODE2 0x01 #define PCA9685_SUBADDR1 0x02 #define PCA9685_SUBADDR2 0x03 #define PCA9685_SUBADDR3 0x04 #define PCA9685_ALLCALLADDR 0x05 #define PCA9685_LEDX_ON_L 0x06 #define PCA9685_LEDX_ON_H 0x07 #define PCA9685_LEDX_OFF_L 0x08 #define PCA9685_LEDX_OFF_H 0x09 #define PCA9685_ALL_LED_ON_L 0xFA #define PCA9685_ALL_LED_ON_H 0xFB #define PCA9685_ALL_LED_OFF_L 0xFC #define PCA9685_ALL_LED_OFF_H 0xFD #define PCA9685_PRESCALE 0xFE #define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */ #define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */ #define PCA9685_COUNTER_RANGE 4096 #define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */ #define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */ #define PCA9685_NUMREGS 0xFF #define PCA9685_MAXCHAN 0x10 #define LED_FULL (1 << 4) #define MODE1_SLEEP (1 << 4) #define MODE2_INVRT (1 << 4) #define MODE2_OUTDRV (1 << 2) #define LED_N_ON_H(N) (PCA9685_LEDX_ON_H + (4 * (N))) #define LED_N_ON_L(N) (PCA9685_LEDX_ON_L + (4 * (N))) #define LED_N_OFF_H(N) (PCA9685_LEDX_OFF_H + (4 * (N))) #define LED_N_OFF_L(N) (PCA9685_LEDX_OFF_L + (4 * (N))) struct pca9685 { struct pwm_chip chip; struct regmap *regmap; int period_ns; #if IS_ENABLED(CONFIG_GPIOLIB) struct mutex lock; struct gpio_chip gpio; DECLARE_BITMAP(pwms_inuse, PCA9685_MAXCHAN + 1); #endif }; static inline struct pca9685 *to_pca(struct pwm_chip *chip) { return container_of(chip, struct pca9685, chip); } #if IS_ENABLED(CONFIG_GPIOLIB) static bool pca9685_pwm_test_and_set_inuse(struct pca9685 *pca, int pwm_idx) { bool is_inuse; mutex_lock(&pca->lock); 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; } } is_inuse = test_and_set_bit(pwm_idx, pca->pwms_inuse); out: mutex_unlock(&pca->lock); return is_inuse; } static void pca9685_pwm_clear_inuse(struct pca9685 *pca, int pwm_idx) { mutex_lock(&pca->lock); clear_bit(pwm_idx, pca->pwms_inuse); mutex_unlock(&pca->lock); } static int pca9685_pwm_gpio_request(struct gpio_chip *gpio, unsigned int offset) { struct pca9685 *pca = gpiochip_get_data(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) { 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 void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset) { struct pca9685 *pca = gpiochip_get_data(gpio); pca9685_pwm_gpio_set(gpio, offset, 0); pm_runtime_put(pca->chip.dev); pca9685_pwm_clear_inuse(pca, offset); } static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip, unsigned int offset) { /* Always out */ return GPIO_LINE_DIRECTION_OUT; } 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_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; } #endif static void pca9685_set_sleep_mode(struct pca9685 *pca, bool enable) { regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, enable ? MODE1_SLEEP : 0); if (!enable) { /* 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) { struct pca9685 *pca = to_pca(chip); unsigned long long duty; unsigned int reg; int prescale; if (period_ns != pca->period_ns) { prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns, PCA9685_COUNTER_RANGE * 1000) - 1; 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 */ pca9685_set_sleep_mode(pca, true); /* Change the chip-wide output frequency */ regmap_write(pca->regmap, PCA9685_PRESCALE, prescale); /* Wake the chip up */ pca9685_set_sleep_mode(pca, false); pca->period_ns = period_ns; } else { dev_err(chip->dev, "prescaler not set: period out of bounds!\n"); return -EINVAL; } } if (duty_ns < 1) { if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_H; else reg = LED_N_OFF_H(pwm->hwpwm); regmap_write(pca->regmap, reg, LED_FULL); return 0; } if (duty_ns == period_ns) { /* Clear both OFF registers */ if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_L; else reg = LED_N_OFF_L(pwm->hwpwm); regmap_write(pca->regmap, reg, 0x0); if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_H; else reg = LED_N_OFF_H(pwm->hwpwm); regmap_write(pca->regmap, reg, 0x0); /* Set the full ON bit */ if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_ON_H; else reg = LED_N_ON_H(pwm->hwpwm); regmap_write(pca->regmap, reg, LED_FULL); return 0; } duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns; duty = DIV_ROUND_UP_ULL(duty, period_ns); if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_L; else reg = LED_N_OFF_L(pwm->hwpwm); regmap_write(pca->regmap, reg, (int)duty & 0xff); if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_H; else reg = LED_N_OFF_H(pwm->hwpwm); regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf); /* Clear the full ON bit, otherwise the set OFF time has no effect */ if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_ON_H; else reg = LED_N_ON_H(pwm->hwpwm); regmap_write(pca->regmap, reg, 0); return 0; } static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pca9685 *pca = to_pca(chip); unsigned int reg; /* * The PWM subsystem does not support a pre-delay. * So, set the ON-timeout to 0 */ if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_ON_L; else reg = LED_N_ON_L(pwm->hwpwm); regmap_write(pca->regmap, reg, 0); if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_ON_H; else reg = LED_N_ON_H(pwm->hwpwm); regmap_write(pca->regmap, reg, 0); /* * Clear the full-off bit. * It has precedence over the others and must be off. */ if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_H; else reg = LED_N_OFF_H(pwm->hwpwm); regmap_update_bits(pca->regmap, reg, LED_FULL, 0x0); return 0; } static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct pca9685 *pca = to_pca(chip); unsigned int reg; if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_H; else reg = LED_N_OFF_H(pwm->hwpwm); regmap_write(pca->regmap, reg, LED_FULL); /* Clear the LED_OFF counter. */ if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_L; else reg = LED_N_OFF_L(pwm->hwpwm); regmap_write(pca->regmap, reg, 0x0); } static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) { struct pca9685 *pca = to_pca(chip); if (pca9685_pwm_test_and_set_inuse(pca, pwm->hwpwm)) return -EBUSY; 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); 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 = { .enable = pca9685_pwm_enable, .disable = pca9685_pwm_disable, .config = pca9685_pwm_config, .request = pca9685_pwm_request, .free = pca9685_pwm_free, .owner = THIS_MODULE, }; static const struct regmap_config pca9685_regmap_i2c_config = { .reg_bits = 8, .val_bits = 8, .max_register = PCA9685_NUMREGS, .cache_type = REGCACHE_NONE, }; static int pca9685_pwm_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct pca9685 *pca; int ret; int mode2; pca = devm_kzalloc(&client->dev, sizeof(*pca), GFP_KERNEL); if (!pca) return -ENOMEM; pca->regmap = devm_regmap_init_i2c(client, &pca9685_regmap_i2c_config); if (IS_ERR(pca->regmap)) { ret = PTR_ERR(pca->regmap); dev_err(&client->dev, "Failed to initialize register map: %d\n", ret); return ret; } pca->period_ns = PCA9685_DEFAULT_PERIOD; i2c_set_clientdata(client, pca); regmap_read(pca->regmap, PCA9685_MODE2, &mode2); if (device_property_read_bool(&client->dev, "invert")) mode2 |= MODE2_INVRT; else mode2 &= ~MODE2_INVRT; if (device_property_read_bool(&client->dev, "open-drain")) mode2 &= ~MODE2_OUTDRV; else mode2 |= MODE2_OUTDRV; regmap_write(pca->regmap, PCA9685_MODE2, mode2); /* clear all "full off" bits */ regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); pca->chip.ops = &pca9685_pwm_ops; /* add an extra channel for ALL_LED */ pca->chip.npwm = PCA9685_MAXCHAN + 1; pca->chip.dev = &client->dev; pca->chip.base = -1; 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; } /* 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 0; } static int pca9685_pwm_remove(struct i2c_client *client) { struct pca9685 *pca = i2c_get_clientdata(client); int ret; ret = pwmchip_remove(&pca->chip); if (ret) return ret; pm_runtime_disable(&client->dev); return 0; } static int __maybe_unused 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, true); return 0; } static int __maybe_unused 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, false); return 0; } static const struct i2c_device_id pca9685_id[] = { { "pca9685", 0 }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(i2c, pca9685_id); #ifdef CONFIG_ACPI static const struct acpi_device_id pca9685_acpi_ids[] = { { "INT3492", 0 }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids); #endif #ifdef CONFIG_OF static const struct of_device_id pca9685_dt_ids[] = { { .compatible = "nxp,pca9685-pwm", }, { /* sentinel */ } }; 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, .id_table = pca9685_id, }; module_i2c_driver(pca9685_i2c_driver); MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de>"); MODULE_DESCRIPTION("PWM driver for PCA9685"); MODULE_LICENSE("GPL");