/*
   * 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
  ");
  			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");