mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
592 lines
14 KiB
592 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Driver for PCA9685 16-channel 12-bit PWM LED controller |
|
* |
|
* Copyright (C) 2013 Steffen Trumtrar <[email protected]> |
|
* Copyright (C) 2015 Clemens Gruber <[email protected]> |
|
* |
|
* 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 BIT(4) |
|
#define MODE1_ALLCALL BIT(0) |
|
#define MODE1_SUB3 BIT(1) |
|
#define MODE1_SUB2 BIT(2) |
|
#define MODE1_SUB1 BIT(3) |
|
#define MODE1_SLEEP BIT(4) |
|
#define MODE2_INVRT BIT(4) |
|
#define MODE2_OUTDRV BIT(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; |
|
unsigned int reg; |
|
int ret; |
|
|
|
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, ®); |
|
|
|
if (device_property_read_bool(&client->dev, "invert")) |
|
reg |= MODE2_INVRT; |
|
else |
|
reg &= ~MODE2_INVRT; |
|
|
|
if (device_property_read_bool(&client->dev, "open-drain")) |
|
reg &= ~MODE2_OUTDRV; |
|
else |
|
reg |= MODE2_OUTDRV; |
|
|
|
regmap_write(pca->regmap, PCA9685_MODE2, reg); |
|
|
|
/* Disable all LED ALLCALL and SUBx addresses to avoid bus collisions */ |
|
regmap_read(pca->regmap, PCA9685_MODE1, ®); |
|
reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3); |
|
regmap_write(pca->regmap, PCA9685_MODE1, reg); |
|
|
|
/* 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 <[email protected]>"); |
|
MODULE_DESCRIPTION("PWM driver for PCA9685"); |
|
MODULE_LICENSE("GPL");
|
|
|