drivers/leds/leds-pca963x.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright 2011 bct electronic GmbH
  * Copyright 2013 Qtechnology/AS
  *
  * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
  * Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
  *
  * Based on leds-pca955x.c
  *
  * This file is subject to the terms and conditions of version 2 of
  * the GNU General Public License.  See the file COPYING in the main
  * directory of this archive for more details.
  *
  * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
  * LED driver for the PCA9634 I2C LED driver (7-bit slave address set by hw.)
  *
  * Note that hardware blinking violates the leds infrastructure driver
  * interface since the hardware only supports blinking all LEDs with the
  * same delay_on/delay_off rates.  That is, only the LEDs that are set to
  * blink will actually blink but all LEDs that are set to blink will blink
  * in identical fashion.  The delay_on/delay_off values of the last LED
  * that is set to blink will be used for all of the blinking LEDs.
  * Hardware blinking is disabled by default but can be enabled by setting
  * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
  * or by adding the 'nxp,hw-blink' property to the DTS.
  */

 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
 #include <linux/leds.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/workqueue.h>
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/platform_data/leds-pca963x.h>

 /* LED select registers determine the source that drives LED outputs */
 #define PCA963X_LED_OFF		0x0	/* LED driver off */
 #define PCA963X_LED_ON		0x1	/* LED driver on */
 #define PCA963X_LED_PWM		0x2	/* Controlled through PWM */
 #define PCA963X_LED_GRP_PWM	0x3	/* Controlled through PWM/GRPPWM */

 #define PCA963X_MODE2_DMBLNK	0x20	/* Enable blinking */

 #define PCA963X_MODE1		0x00
 #define PCA963X_MODE2		0x01
 #define PCA963X_PWM_BASE	0x02

 enum pca963x_type {
 	pca9633,
 	pca9634,
 };

 struct pca963x_chipdef {
 	u8			grppwm;
 	u8			grpfreq;
 	u8			ledout_base;
 	int			n_leds;
 };

 static struct pca963x_chipdef pca963x_chipdefs[] = {
 	[pca9633] = {
 		.grppwm		= 0x6,
 		.grpfreq	= 0x7,
 		.ledout_base	= 0x8,
 		.n_leds		= 4,
 	},
 	[pca9634] = {
 		.grppwm		= 0xa,
 		.grpfreq	= 0xb,
 		.ledout_base	= 0xc,
 		.n_leds		= 8,
 	},
 };

 /* Total blink period in milliseconds */
 #define PCA963X_BLINK_PERIOD_MIN	42
 #define PCA963X_BLINK_PERIOD_MAX	10667

 static const struct i2c_device_id pca963x_id[] = {
 	{ "pca9632", pca9633 },
 	{ "pca9633", pca9633 },
 	{ "pca9634", pca9634 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, pca963x_id);

 enum pca963x_cmd {
 	BRIGHTNESS_SET,
 	BLINK_SET,
 };

 struct pca963x_led;

 struct pca963x {
 	struct pca963x_chipdef *chipdef;
 	struct mutex mutex;
 	struct i2c_client *client;
 	struct pca963x_led *leds;
 };

 struct pca963x_led {
 	struct pca963x *chip;
 	struct work_struct work;
 	enum led_brightness brightness;
 	struct led_classdev led_cdev;
 	int led_num; /* 0 .. 7 potentially */
 	enum pca963x_cmd cmd;
 	char name[32];
 	u8 gdc;
 	u8 gfrq;
 };

 static void pca963x_brightness_work(struct pca963x_led *pca963x)
 {
 	u8 ledout_addr = pca963x->chip->chipdef->ledout_base
 		+ (pca963x->led_num / 4);
 	u8 ledout;
 	int shift = 2 * (pca963x->led_num % 4);
 	u8 mask = 0x3 << shift;

 	mutex_lock(&pca963x->chip->mutex);
 	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 	switch (pca963x->brightness) {
 	case LED_FULL:
 		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 			(ledout & ~mask) | (PCA963X_LED_ON << shift));
 		break;
 	case LED_OFF:
 		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 			ledout & ~mask);
 		break;
 	default:
 		i2c_smbus_write_byte_data(pca963x->chip->client,
 			PCA963X_PWM_BASE + pca963x->led_num,
 			pca963x->brightness);
 		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 			(ledout & ~mask) | (PCA963X_LED_PWM << shift));
 		break;
 	}
 	mutex_unlock(&pca963x->chip->mutex);
 }

 static void pca963x_blink_work(struct pca963x_led *pca963x)
 {
 	u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
 		(pca963x->led_num / 4);
 	u8 ledout;
 	u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
 							PCA963X_MODE2);
 	int shift = 2 * (pca963x->led_num % 4);
 	u8 mask = 0x3 << shift;

 	i2c_smbus_write_byte_data(pca963x->chip->client,
 			pca963x->chip->chipdef->grppwm,	pca963x->gdc);

 	i2c_smbus_write_byte_data(pca963x->chip->client,
 			pca963x->chip->chipdef->grpfreq, pca963x->gfrq);

 	if (!(mode2 & PCA963X_MODE2_DMBLNK))
 		i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
 			mode2 | PCA963X_MODE2_DMBLNK);

 	mutex_lock(&pca963x->chip->mutex);
 	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
 	if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
 		i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
 			(ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
 	mutex_unlock(&pca963x->chip->mutex);
 }

 static void pca963x_work(struct work_struct *work)
 {
 	struct pca963x_led *pca963x = container_of(work,
 		struct pca963x_led, work);

 	switch (pca963x->cmd) {
 	case BRIGHTNESS_SET:
 		pca963x_brightness_work(pca963x);
 		break;
 	case BLINK_SET:
 		pca963x_blink_work(pca963x);
 		break;
 	}
 }

 static void pca963x_led_set(struct led_classdev *led_cdev,
 	enum led_brightness value)
 {
 	struct pca963x_led *pca963x;

 	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

 	pca963x->cmd = BRIGHTNESS_SET;
 	pca963x->brightness = value;

 	/*
 	 * Must use workqueue for the actual I/O since I2C operations
 	 * can sleep.
 	 */
 	schedule_work(&pca963x->work);
 }

 static int pca963x_blink_set(struct led_classdev *led_cdev,
 		unsigned long *delay_on, unsigned long *delay_off)
 {
 	struct pca963x_led *pca963x;
 	unsigned long time_on, time_off, period;
 	u8 gdc, gfrq;

 	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

 	time_on = *delay_on;
 	time_off = *delay_off;

 	/* If both zero, pick reasonable defaults of 500ms each */
 	if (!time_on && !time_off) {
 		time_on = 500;
 		time_off = 500;
 	}

 	period = time_on + time_off;

 	/* If period not supported by hardware, default to someting sane. */
 	if ((period < PCA963X_BLINK_PERIOD_MIN) ||
 	    (period > PCA963X_BLINK_PERIOD_MAX)) {
 		time_on = 500;
 		time_off = 500;
 		period = time_on + time_off;
 	}

 	/*
 	 * From manual: duty cycle = (GDC / 256) ->
 	 *	(time_on / period) = (GDC / 256) ->
 	 *		GDC = ((time_on * 256) / period)
 	 */
 	gdc = (time_on * 256) / period;

 	/*
 	 * From manual: period = ((GFRQ + 1) / 24) in seconds.
 	 * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
 	 *		GFRQ = ((period * 24 / 1000) - 1)
 	 */
 	gfrq = (period * 24 / 1000) - 1;

 	pca963x->cmd = BLINK_SET;
 	pca963x->gdc = gdc;
 	pca963x->gfrq = gfrq;

 	/*
 	 * Must use workqueue for the actual I/O since I2C operations
 	 * can sleep.
 	 */
 	schedule_work(&pca963x->work);

 	*delay_on = time_on;
 	*delay_off = time_off;

 	return 0;
 }

 #if IS_ENABLED(CONFIG_OF)
 static struct pca963x_platform_data *
 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 {
 	struct device_node *np = client->dev.of_node, *child;
 	struct pca963x_platform_data *pdata;
 	struct led_info *pca963x_leds;
 	int count;

 	count = of_get_child_count(np);
 	if (!count || count > chip->n_leds)
 		return ERR_PTR(-ENODEV);

 	pca963x_leds = devm_kzalloc(&client->dev,
 			sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
 	if (!pca963x_leds)
 		return ERR_PTR(-ENOMEM);

 	for_each_child_of_node(np, child) {
 		struct led_info led;
 		u32 reg;
 		int res;

 		res = of_property_read_u32(child, "reg", &reg);
 		if ((res != 0) || (reg >= chip->n_leds))
 			continue;
 		led.name =
 			of_get_property(child, "label", NULL) ? : child->name;
 		led.default_trigger =
 			of_get_property(child, "linux,default-trigger", NULL);
 		pca963x_leds[reg] = led;
 	}
 	pdata = devm_kzalloc(&client->dev,
 			     sizeof(struct pca963x_platform_data), GFP_KERNEL);
 	if (!pdata)
 		return ERR_PTR(-ENOMEM);

 	pdata->leds.leds = pca963x_leds;
 	pdata->leds.num_leds = chip->n_leds;

 	/* default to open-drain unless totem pole (push-pull) is specified */
 	if (of_property_read_bool(np, "nxp,totem-pole"))
 		pdata->outdrv = PCA963X_TOTEM_POLE;
 	else
 		pdata->outdrv = PCA963X_OPEN_DRAIN;

 	/* default to software blinking unless hardware blinking is specified */
 	if (of_property_read_bool(np, "nxp,hw-blink"))
 		pdata->blink_type = PCA963X_HW_BLINK;
 	else
 		pdata->blink_type = PCA963X_SW_BLINK;

 	return pdata;
 }

 static const struct of_device_id of_pca963x_match[] = {
 	{ .compatible = "nxp,pca9632", },
 	{ .compatible = "nxp,pca9633", },
 	{ .compatible = "nxp,pca9634", },
 	{},
 };
 #else
 static struct pca963x_platform_data *
 pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
 {
 	return ERR_PTR(-ENODEV);
 }
 #endif

 static int pca963x_probe(struct i2c_client *client,
 					const struct i2c_device_id *id)
 {
 	struct pca963x *pca963x_chip;
 	struct pca963x_led *pca963x;
 	struct pca963x_platform_data *pdata;
 	struct pca963x_chipdef *chip;
 	int i, err;

 	chip = &pca963x_chipdefs[id->driver_data];
 	pdata = dev_get_platdata(&client->dev);

 	if (!pdata) {
 		pdata = pca963x_dt_init(client, chip);
 		if (IS_ERR(pdata)) {
 			dev_warn(&client->dev, "could not parse configuration\n");
 			pdata = NULL;
 		}
 	}

 	if (pdata && (pdata->leds.num_leds < 1 ||
 				 pdata->leds.num_leds > chip->n_leds)) {
 		dev_err(&client->dev, "board info must claim 1-%d LEDs",
 								chip->n_leds);
 		return -EINVAL;
 	}

 	pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
 								GFP_KERNEL);
 	if (!pca963x_chip)
 		return -ENOMEM;
 	pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
 								GFP_KERNEL);
 	if (!pca963x)
 		return -ENOMEM;

 	i2c_set_clientdata(client, pca963x_chip);

 	mutex_init(&pca963x_chip->mutex);
 	pca963x_chip->chipdef = chip;
 	pca963x_chip->client = client;
 	pca963x_chip->leds = pca963x;

 	/* Turn off LEDs by default*/
 	i2c_smbus_write_byte_data(client, chip->ledout_base, 0x00);
 	if (chip->n_leds > 4)
 		i2c_smbus_write_byte_data(client, chip->ledout_base + 1, 0x00);

 	for (i = 0; i < chip->n_leds; i++) {
 		pca963x[i].led_num = i;
 		pca963x[i].chip = pca963x_chip;

 		/* Platform data can specify LED names and default triggers */
 		if (pdata && i < pdata->leds.num_leds) {
 			if (pdata->leds.leds[i].name)
 				snprintf(pca963x[i].name,
 					 sizeof(pca963x[i].name), "pca963x:%s",
 					 pdata->leds.leds[i].name);
 			if (pdata->leds.leds[i].default_trigger)
 				pca963x[i].led_cdev.default_trigger =
 					pdata->leds.leds[i].default_trigger;
 		}
 		if (!pdata || i >= pdata->leds.num_leds ||
 						!pdata->leds.leds[i].name)
 			snprintf(pca963x[i].name, sizeof(pca963x[i].name),
 				 "pca963x:%d:%.2x:%d", client->adapter->nr,
 				 client->addr, i);

 		pca963x[i].led_cdev.name = pca963x[i].name;
 		pca963x[i].led_cdev.brightness_set = pca963x_led_set;

 		if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
 			pca963x[i].led_cdev.blink_set = pca963x_blink_set;

 		INIT_WORK(&pca963x[i].work, pca963x_work);

 		err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
 		if (err < 0)
 			goto exit;
 	}

 	/* Disable LED all-call address and set normal mode */
 	i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);

 	/* Configure output: open-drain or totem pole (push-pull) */
 	if (pdata && pdata->outdrv == PCA963X_OPEN_DRAIN)
 		i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);

 	return 0;

 exit:
 	while (i--) {
 		led_classdev_unregister(&pca963x[i].led_cdev);
 		cancel_work_sync(&pca963x[i].work);
 	}

 	return err;
 }

 static int pca963x_remove(struct i2c_client *client)
 {
 	struct pca963x *pca963x = i2c_get_clientdata(client);
 	int i;

 	for (i = 0; i < pca963x->chipdef->n_leds; i++) {
 		led_classdev_unregister(&pca963x->leds[i].led_cdev);
 		cancel_work_sync(&pca963x->leds[i].work);
 	}

 	return 0;
 }

 static struct i2c_driver pca963x_driver = {
 	.driver = {
 		.name	= "leds-pca963x",
 		.owner	= THIS_MODULE,
 		.of_match_table = of_match_ptr(of_pca963x_match),
 	},
 	.probe	= pca963x_probe,
 	.remove	= pca963x_remove,
 	.id_table = pca963x_id,
 };

 module_i2c_driver(pca963x_driver);

 MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
 MODULE_DESCRIPTION("PCA963X LED driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright 2011 bct electronic GmbH
	* Copyright 2013 Qtechnology/AS
	*
	* Author: Peter Meerwald <p.meerwald@bct-electronic.com>
	* Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
	*
	* Based on leds-pca955x.c
	*
	* This file is subject to the terms and conditions of version 2 of
	* the GNU General Public License. See the file COPYING in the main
	* directory of this archive for more details.
	*
	* LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
	* LED driver for the PCA9634 I2C LED driver (7-bit slave address set by hw.)
	*
	* Note that hardware blinking violates the leds infrastructure driver
	* interface since the hardware only supports blinking all LEDs with the
	* same delay_on/delay_off rates. That is, only the LEDs that are set to
	* blink will actually blink but all LEDs that are set to blink will blink
	* in identical fashion. The delay_on/delay_off values of the last LED
	* that is set to blink will be used for all of the blinking LEDs.
	* Hardware blinking is disabled by default but can be enabled by setting
	* the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
	* or by adding the 'nxp,hw-blink' property to the DTS.
	*/

	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/string.h>
	#include <linux/ctype.h>
	#include <linux/leds.h>
	#include <linux/err.h>
	#include <linux/i2c.h>
	#include <linux/workqueue.h>
	#include <linux/slab.h>
	#include <linux/of.h>
	#include <linux/platform_data/leds-pca963x.h>

	/* LED select registers determine the source that drives LED outputs */
	#define PCA963X_LED_OFF 0x0 /* LED driver off */
	#define PCA963X_LED_ON 0x1 /* LED driver on */
	#define PCA963X_LED_PWM 0x2 /* Controlled through PWM */
	#define PCA963X_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */

	#define PCA963X_MODE2_DMBLNK 0x20 /* Enable blinking */

	#define PCA963X_MODE1 0x00
	#define PCA963X_MODE2 0x01
	#define PCA963X_PWM_BASE 0x02

	enum pca963x_type {
	pca9633,
	pca9634,
	};

	struct pca963x_chipdef {
	u8 grppwm;
	u8 grpfreq;
	u8 ledout_base;
	int n_leds;
	};

	static struct pca963x_chipdef pca963x_chipdefs[] = {
	[pca9633] = {
	.grppwm = 0x6,
	.grpfreq = 0x7,
	.ledout_base = 0x8,
	.n_leds = 4,
	},
	[pca9634] = {
	.grppwm = 0xa,
	.grpfreq = 0xb,
	.ledout_base = 0xc,
	.n_leds = 8,
	},
	};

	/* Total blink period in milliseconds */
	#define PCA963X_BLINK_PERIOD_MIN 42
	#define PCA963X_BLINK_PERIOD_MAX 10667

	static const struct i2c_device_id pca963x_id[] = {
	{ "pca9632", pca9633 },
	{ "pca9633", pca9633 },
	{ "pca9634", pca9634 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, pca963x_id);

	enum pca963x_cmd {
	BRIGHTNESS_SET,
	BLINK_SET,
	};

	struct pca963x_led;

	struct pca963x {
	struct pca963x_chipdef *chipdef;
	struct mutex mutex;
	struct i2c_client *client;
	struct pca963x_led *leds;
	};

	struct pca963x_led {
	struct pca963x *chip;
	struct work_struct work;
	enum led_brightness brightness;
	struct led_classdev led_cdev;
	int led_num; /* 0 .. 7 potentially */
	enum pca963x_cmd cmd;
	char name[32];
	u8 gdc;
	u8 gfrq;
	};

	static void pca963x_brightness_work(struct pca963x_led *pca963x)
	{
	u8 ledout_addr = pca963x->chip->chipdef->ledout_base
	+ (pca963x->led_num / 4);
	u8 ledout;
	int shift = 2 * (pca963x->led_num % 4);
	u8 mask = 0x3 << shift;

	mutex_lock(&pca963x->chip->mutex);
	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
	switch (pca963x->brightness) {
	case LED_FULL:
	i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
	(ledout & ~mask) \| (PCA963X_LED_ON << shift));
	break;
	case LED_OFF:
	i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
	ledout & ~mask);
	break;
	default:
	i2c_smbus_write_byte_data(pca963x->chip->client,
	PCA963X_PWM_BASE + pca963x->led_num,
	pca963x->brightness);
	i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
	(ledout & ~mask) \| (PCA963X_LED_PWM << shift));
	break;
	}
	mutex_unlock(&pca963x->chip->mutex);
	}

	static void pca963x_blink_work(struct pca963x_led *pca963x)
	{
	u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
	(pca963x->led_num / 4);
	u8 ledout;
	u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
	PCA963X_MODE2);
	int shift = 2 * (pca963x->led_num % 4);
	u8 mask = 0x3 << shift;

	i2c_smbus_write_byte_data(pca963x->chip->client,
	pca963x->chip->chipdef->grppwm, pca963x->gdc);

	i2c_smbus_write_byte_data(pca963x->chip->client,
	pca963x->chip->chipdef->grpfreq, pca963x->gfrq);

	if (!(mode2 & PCA963X_MODE2_DMBLNK))
	i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
	mode2 \| PCA963X_MODE2_DMBLNK);

	mutex_lock(&pca963x->chip->mutex);
	ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
	if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
	i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
	(ledout & ~mask) \| (PCA963X_LED_GRP_PWM << shift));
	mutex_unlock(&pca963x->chip->mutex);
	}

	static void pca963x_work(struct work_struct *work)
	{
	struct pca963x_led *pca963x = container_of(work,
	struct pca963x_led, work);

	switch (pca963x->cmd) {
	case BRIGHTNESS_SET:
	pca963x_brightness_work(pca963x);
	break;
	case BLINK_SET:
	pca963x_blink_work(pca963x);
	break;
	}
	}

	static void pca963x_led_set(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	struct pca963x_led *pca963x;

	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

	pca963x->cmd = BRIGHTNESS_SET;
	pca963x->brightness = value;

	/*
	* Must use workqueue for the actual I/O since I2C operations
	* can sleep.
	*/
	schedule_work(&pca963x->work);
	}

	static int pca963x_blink_set(struct led_classdev *led_cdev,
	unsigned long delay_on, unsigned long delay_off)
	{
	struct pca963x_led *pca963x;
	unsigned long time_on, time_off, period;
	u8 gdc, gfrq;

	pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

	time_on = *delay_on;
	time_off = *delay_off;

	/* If both zero, pick reasonable defaults of 500ms each */
	if (!time_on && !time_off) {
	time_on = 500;
	time_off = 500;
	}

	period = time_on + time_off;

	/* If period not supported by hardware, default to someting sane. */
	if ((period < PCA963X_BLINK_PERIOD_MIN) \|\|
	(period > PCA963X_BLINK_PERIOD_MAX)) {
	time_on = 500;
	time_off = 500;
	period = time_on + time_off;
	}

	/*
	* From manual: duty cycle = (GDC / 256) ->
	* (time_on / period) = (GDC / 256) ->
	* GDC = ((time_on * 256) / period)
	*/
	gdc = (time_on * 256) / period;

	/*
	* From manual: period = ((GFRQ + 1) / 24) in seconds.
	* So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
	* GFRQ = ((period * 24 / 1000) - 1)
	*/
	gfrq = (period * 24 / 1000) - 1;

	pca963x->cmd = BLINK_SET;
	pca963x->gdc = gdc;
	pca963x->gfrq = gfrq;

	/*
	* Must use workqueue for the actual I/O since I2C operations
	* can sleep.
	*/
	schedule_work(&pca963x->work);

	*delay_on = time_on;
	*delay_off = time_off;

	return 0;
	}

	#if IS_ENABLED(CONFIG_OF)
	static struct pca963x_platform_data *
	pca963x_dt_init(struct i2c_client client, struct pca963x_chipdef chip)
	{
	struct device_node np = client->dev.of_node, child;
	struct pca963x_platform_data *pdata;
	struct led_info *pca963x_leds;
	int count;

	count = of_get_child_count(np);
	if (!count \|\| count > chip->n_leds)
	return ERR_PTR(-ENODEV);

	pca963x_leds = devm_kzalloc(&client->dev,
	sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
	if (!pca963x_leds)
	return ERR_PTR(-ENOMEM);

	for_each_child_of_node(np, child) {
	struct led_info led;
	u32 reg;
	int res;

	res = of_property_read_u32(child, "reg", &reg);
	if ((res != 0) \|\| (reg >= chip->n_leds))
	continue;
	led.name =
	of_get_property(child, "label", NULL) ? : child->name;
	led.default_trigger =
	of_get_property(child, "linux,default-trigger", NULL);
	pca963x_leds[reg] = led;
	}
	pdata = devm_kzalloc(&client->dev,
	sizeof(struct pca963x_platform_data), GFP_KERNEL);
	if (!pdata)
	return ERR_PTR(-ENOMEM);

	pdata->leds.leds = pca963x_leds;
	pdata->leds.num_leds = chip->n_leds;

	/* default to open-drain unless totem pole (push-pull) is specified */
	if (of_property_read_bool(np, "nxp,totem-pole"))
	pdata->outdrv = PCA963X_TOTEM_POLE;
	else
	pdata->outdrv = PCA963X_OPEN_DRAIN;

	/* default to software blinking unless hardware blinking is specified */
	if (of_property_read_bool(np, "nxp,hw-blink"))
	pdata->blink_type = PCA963X_HW_BLINK;
	else
	pdata->blink_type = PCA963X_SW_BLINK;

	return pdata;
	}

	static const struct of_device_id of_pca963x_match[] = {
	{ .compatible = "nxp,pca9632", },
	{ .compatible = "nxp,pca9633", },
	{ .compatible = "nxp,pca9634", },
	{},
	};
	#else
	static struct pca963x_platform_data *
	pca963x_dt_init(struct i2c_client client, struct pca963x_chipdef chip)
	{
	return ERR_PTR(-ENODEV);
	}
	#endif

	static int pca963x_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct pca963x *pca963x_chip;
	struct pca963x_led *pca963x;
	struct pca963x_platform_data *pdata;
	struct pca963x_chipdef *chip;
	int i, err;

	chip = &pca963x_chipdefs[id->driver_data];
	pdata = dev_get_platdata(&client->dev);

	if (!pdata) {
	pdata = pca963x_dt_init(client, chip);
	if (IS_ERR(pdata)) {
	dev_warn(&client->dev, "could not parse configuration\n");
	pdata = NULL;
	}
	}

	if (pdata && (pdata->leds.num_leds < 1 \|\|
	pdata->leds.num_leds > chip->n_leds)) {
	dev_err(&client->dev, "board info must claim 1-%d LEDs",
	chip->n_leds);
	return -EINVAL;
	}

	pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
	GFP_KERNEL);
	if (!pca963x_chip)
	return -ENOMEM;
	pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
	GFP_KERNEL);
	if (!pca963x)
	return -ENOMEM;

	i2c_set_clientdata(client, pca963x_chip);

	mutex_init(&pca963x_chip->mutex);
	pca963x_chip->chipdef = chip;
	pca963x_chip->client = client;
	pca963x_chip->leds = pca963x;

	/* Turn off LEDs by default*/
	i2c_smbus_write_byte_data(client, chip->ledout_base, 0x00);
	if (chip->n_leds > 4)
	i2c_smbus_write_byte_data(client, chip->ledout_base + 1, 0x00);

	for (i = 0; i < chip->n_leds; i++) {
	pca963x[i].led_num = i;
	pca963x[i].chip = pca963x_chip;

	/* Platform data can specify LED names and default triggers */
	if (pdata && i < pdata->leds.num_leds) {
	if (pdata->leds.leds[i].name)
	snprintf(pca963x[i].name,
	sizeof(pca963x[i].name), "pca963x:%s",
	pdata->leds.leds[i].name);
	if (pdata->leds.leds[i].default_trigger)
	pca963x[i].led_cdev.default_trigger =
	pdata->leds.leds[i].default_trigger;
	}
	if (!pdata \|\| i >= pdata->leds.num_leds \|\|
	!pdata->leds.leds[i].name)
	snprintf(pca963x[i].name, sizeof(pca963x[i].name),
	"pca963x:%d:%.2x:%d", client->adapter->nr,
	client->addr, i);

	pca963x[i].led_cdev.name = pca963x[i].name;
	pca963x[i].led_cdev.brightness_set = pca963x_led_set;

	if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
	pca963x[i].led_cdev.blink_set = pca963x_blink_set;

	INIT_WORK(&pca963x[i].work, pca963x_work);

	err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
	if (err < 0)
	goto exit;
	}

	/* Disable LED all-call address and set normal mode */
	i2c_smbus_write_byte_data(client, PCA963X_MODE1, 0x00);

	/* Configure output: open-drain or totem pole (push-pull) */
	if (pdata && pdata->outdrv == PCA963X_OPEN_DRAIN)
	i2c_smbus_write_byte_data(client, PCA963X_MODE2, 0x01);

	return 0;

	exit:
	while (i--) {
	led_classdev_unregister(&pca963x[i].led_cdev);
	cancel_work_sync(&pca963x[i].work);
	}

	return err;
	}

	static int pca963x_remove(struct i2c_client *client)
	{
	struct pca963x *pca963x = i2c_get_clientdata(client);
	int i;

	for (i = 0; i < pca963x->chipdef->n_leds; i++) {
	led_classdev_unregister(&pca963x->leds[i].led_cdev);
	cancel_work_sync(&pca963x->leds[i].work);
	}

	return 0;
	}

	static struct i2c_driver pca963x_driver = {
	.driver = {
	.name = "leds-pca963x",
	.owner = THIS_MODULE,
	.of_match_table = of_match_ptr(of_pca963x_match),
	},
	.probe = pca963x_probe,
	.remove = pca963x_remove,
	.id_table = pca963x_id,
	};

	module_i2c_driver(pca963x_driver);

	MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
	MODULE_DESCRIPTION("PCA963X LED driver");
	MODULE_LICENSE("GPL v2");