drivers/pwm/pwm-pca9685.c - kernel/lockdown - Git at Google

 /*
  * Driver for PCA9685 16-channel 12-bit PWM LED controller
  *
  * Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
  *
  * based on the pwm-twl-led.c driver
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>

 #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_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 active_cnt;
 };

 static inline struct pca9685 *to_pca(struct pwm_chip *chip)
 {
 	return container_of(chip, struct pca9685, chip);
 }

 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;

 	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) {
 		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 = 4096 * (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);

 	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 (pca->active_cnt++ == 0)
 		return regmap_update_bits(pca->regmap, PCA9685_MODE1,
 					  MODE1_SLEEP, 0x0);

 	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);
 }

 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 device_node *np = client->dev.of_node;
 	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;
 	}

 	i2c_set_clientdata(client, pca);

 	regmap_read(pca->regmap, PCA9685_MODE2, &mode2);

 	if (of_property_read_bool(np, "invert"))
 		mode2 |= MODE2_INVRT;
 	else
 		mode2 &= ~MODE2_INVRT;

 	if (of_property_read_bool(np, "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;
 	pca->chip.can_sleep = true;

 	return pwmchip_add(&pca->chip);
 }

 static int pca9685_pwm_remove(struct i2c_client *client)
 {
 	struct pca9685 *pca = i2c_get_clientdata(client);

 	regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP,
 			   MODE1_SLEEP);

 	return pwmchip_remove(&pca->chip);
 }

 static const struct i2c_device_id pca9685_id[] = {
 	{ "pca9685", 0 },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(i2c, pca9685_id);

 static const struct of_device_id pca9685_dt_ids[] = {
 	{ .compatible = "nxp,pca9685-pwm", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, pca9685_dt_ids);

 static struct i2c_driver pca9685_i2c_driver = {
 	.driver = {
 		.name = "pca9685-pwm",
 		.owner = THIS_MODULE,
 		.of_match_table = pca9685_dt_ids,
 	},
 	.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");
	/*
	* Driver for PCA9685 16-channel 12-bit PWM LED controller
	*
	* Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
	*
	* based on the pwm-twl-led.c driver
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/pwm.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>

	#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_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 active_cnt;
	};

	static inline struct pca9685 to_pca(struct pwm_chip chip)
	{
	return container_of(chip, struct pca9685, chip);
	}

	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;

	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) {
	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 = 4096 * (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);

	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 (pca->active_cnt++ == 0)
	return regmap_update_bits(pca->regmap, PCA9685_MODE1,
	MODE1_SLEEP, 0x0);

	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);
	}

	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 device_node *np = client->dev.of_node;
	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;
	}

	i2c_set_clientdata(client, pca);

	regmap_read(pca->regmap, PCA9685_MODE2, &mode2);

	if (of_property_read_bool(np, "invert"))
	mode2 \|= MODE2_INVRT;
	else
	mode2 &= ~MODE2_INVRT;

	if (of_property_read_bool(np, "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;
	pca->chip.can_sleep = true;

	return pwmchip_add(&pca->chip);
	}

	static int pca9685_pwm_remove(struct i2c_client *client)
	{
	struct pca9685 *pca = i2c_get_clientdata(client);

	regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP,
	MODE1_SLEEP);

	return pwmchip_remove(&pca->chip);
	}

	static const struct i2c_device_id pca9685_id[] = {
	{ "pca9685", 0 },
	{ /* sentinel */ },
	};
	MODULE_DEVICE_TABLE(i2c, pca9685_id);

	static const struct of_device_id pca9685_dt_ids[] = {
	{ .compatible = "nxp,pca9685-pwm", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, pca9685_dt_ids);

	static struct i2c_driver pca9685_i2c_driver = {
	.driver = {
	.name = "pca9685-pwm",
	.owner = THIS_MODULE,
	.of_match_table = pca9685_dt_ids,
	},
	.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");