/*
   * pca9532.c - 16-bit Led dimmer
   *

   * Copyright (C) 2011 Jan Weitzel

   * Copyright (C) 2008 Riku Voipio

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; version 2 of the License.
   *

   * Datasheet: http://www.nxp.com/documents/data_sheet/PCA9532.pdf

   *
   */
  
  #include <linux/module.h>
  #include <linux/i2c.h>

  #include <linux/slab.h>

  #include <linux/leds.h>
  #include <linux/input.h>
  #include <linux/mutex.h>

  #include <linux/workqueue.h>

  #include <linux/leds-pca9532.h>

  #include <linux/gpio.h>

  /* m =  num_leds*/
  #define PCA9532_REG_INPUT(i)	((i) >> 3)
  #define PCA9532_REG_OFFSET(m)	((m) >> 4)
  #define PCA9532_REG_PSC(m, i)	(PCA9532_REG_OFFSET(m) + 0x1 + (i) * 2)
  #define PCA9532_REG_PWM(m, i)	(PCA9532_REG_OFFSET(m) + 0x2 + (i) * 2)
  #define LED_REG(m, led)		(PCA9532_REG_OFFSET(m) + 0x5 + (led >> 2))
  #define LED_NUM(led)		(led & 0x3)

  
  #define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)

  struct pca9532_chip_info {
  	u8	num_leds;
  };

  struct pca9532_data {
  	struct i2c_client *client;
  	struct pca9532_led leds[16];
  	struct mutex update_lock;

  	struct input_dev *idev;

  	struct work_struct work;

  #ifdef CONFIG_LEDS_PCA9532_GPIO
  	struct gpio_chip gpio;
  #endif

  	const struct pca9532_chip_info *chip_info;

  	u8 pwm[2];
  	u8 psc[2];
  };
  
  static int pca9532_probe(struct i2c_client *client,
  	const struct i2c_device_id *id);
  static int pca9532_remove(struct i2c_client *client);

  enum {
  	pca9530,
  	pca9531,
  	pca9532,
  	pca9533,
  };

  static const struct i2c_device_id pca9532_id[] = {

  	{ "pca9530", pca9530 },
  	{ "pca9531", pca9531 },
  	{ "pca9532", pca9532 },
  	{ "pca9533", pca9533 },

  	{ }
  };
  
  MODULE_DEVICE_TABLE(i2c, pca9532_id);

  static const struct pca9532_chip_info pca9532_chip_info_tbl[] = {
  	[pca9530] = {
  		.num_leds = 2,
  	},
  	[pca9531] = {
  		.num_leds = 8,
  	},
  	[pca9532] = {
  		.num_leds = 16,
  	},
  	[pca9533] = {
  		.num_leds = 4,
  	},
  };

  static struct i2c_driver pca9532_driver = {
  	.driver = {

  		.name = "leds-pca953x",

  	},

  	.probe = pca9532_probe,

  	.remove = pca9532_remove,
  	.id_table = pca9532_id,
  };

  /* We have two pwm/blinkers, but 16 possible leds to drive. Additionally,

   * the clever Thecus people are using one pwm to drive the beeper. So,
   * as a compromise we average one pwm to the values requested by all
   * leds that are not ON/OFF.
   * */

  static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,

  	enum led_brightness value)
  {
  	int a = 0, b = 0, i = 0;
  	struct pca9532_data *data = i2c_get_clientdata(client);

  	for (i = 0; i < data->chip_info->num_leds; i++) {

  		if (data->leds[i].type == PCA9532_TYPE_LED &&
  			data->leds[i].state == PCA9532_PWM0+pwm) {
  				a++;
  				b += data->leds[i].ldev.brightness;
  		}
  	}
  	if (a == 0) {
  		dev_err(&client->dev,
  		"fear of division by zero %d/%d, wanted %d
  ",
  			b, a, value);
  		return -EINVAL;
  	}
  	b = b/a;
  	if (b > 0xFF)
  		return -EINVAL;

  	data->pwm[pwm] = b;

  	data->psc[pwm] = blink;
  	return 0;

  }
  
  static int pca9532_setpwm(struct i2c_client *client, int pwm)
  {

  	struct pca9532_data *data = i2c_get_clientdata(client);

  	u8 maxleds = data->chip_info->num_leds;

  	mutex_lock(&data->update_lock);

  	i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, pwm),

  		data->pwm[pwm]);

  	i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, pwm),

  		data->psc[pwm]);
  	mutex_unlock(&data->update_lock);
  	return 0;
  }
  
  /* Set LED routing */
  static void pca9532_setled(struct pca9532_led *led)
  {
  	struct i2c_client *client = led->client;
  	struct pca9532_data *data = i2c_get_clientdata(client);

  	u8 maxleds = data->chip_info->num_leds;

  	char reg;
  
  	mutex_lock(&data->update_lock);

  	reg = i2c_smbus_read_byte_data(client, LED_REG(maxleds, led->id));

  	/* zero led bits */
  	reg = reg & ~(0x3<<LED_NUM(led->id)*2);
  	/* set the new value */
  	reg = reg | (led->state << LED_NUM(led->id)*2);

  	i2c_smbus_write_byte_data(client, LED_REG(maxleds, led->id), reg);

  	mutex_unlock(&data->update_lock);
  }
  
  static void pca9532_set_brightness(struct led_classdev *led_cdev,
  	enum led_brightness value)
  {
  	int err = 0;
  	struct pca9532_led *led = ldev_to_led(led_cdev);
  
  	if (value == LED_OFF)
  		led->state = PCA9532_OFF;
  	else if (value == LED_FULL)
  		led->state = PCA9532_ON;
  	else {
  		led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */

  		err = pca9532_calcpwm(led->client, 0, 0, value);

  		if (err)
  			return; /* XXX: led api doesn't allow error code? */
  	}

  	schedule_work(&led->work);

  }
  
  static int pca9532_set_blink(struct led_classdev *led_cdev,
  	unsigned long *delay_on, unsigned long *delay_off)
  {
  	struct pca9532_led *led = ldev_to_led(led_cdev);
  	struct i2c_client *client = led->client;
  	int psc;

  	int err = 0;

  
  	if (*delay_on == 0 && *delay_off == 0) {
  	/* led subsystem ask us for a blink rate */

  		*delay_on = 1000;

  		*delay_off = 1000;
  	}
  	if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
  		return -EINVAL;
  
  	/* Thecus specific: only use PSC/PWM 0 */
  	psc = (*delay_on * 152-1)/1000;

  	err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
  	if (err)
  		return err;
  	schedule_work(&led->work);
  	return 0;

  }

  static int pca9532_event(struct input_dev *dev, unsigned int type,
  	unsigned int code, int value)

  {
  	struct pca9532_data *data = input_get_drvdata(dev);

  	if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))

  		return -1;
  
  	/* XXX: allow different kind of beeps with psc/pwm modifications */
  	if (value > 1 && value < 32767)
  		data->pwm[1] = 127;
  	else
  		data->pwm[1] = 0;

  	schedule_work(&data->work);

  	return 0;

  }
  
  static void pca9532_input_work(struct work_struct *work)
  {

  	struct pca9532_data *data =
  		container_of(work, struct pca9532_data, work);
  	u8 maxleds = data->chip_info->num_leds;

  	mutex_lock(&data->update_lock);

  	i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(maxleds, 1),

  		data->pwm[1]);
  	mutex_unlock(&data->update_lock);

  }

  static void pca9532_led_work(struct work_struct *work)
  {

  	struct pca9532_led *led;
  	led = container_of(work, struct pca9532_led, work);
  	if (led->state == PCA9532_PWM0)
  		pca9532_setpwm(led->client, 0);
  	pca9532_setled(led);

  }

  #ifdef CONFIG_LEDS_PCA9532_GPIO
  static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
  {
  	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
  	struct pca9532_led *led = &data->leds[offset];
  
  	if (led->type == PCA9532_TYPE_GPIO)
  		return 0;
  
  	return -EBUSY;
  }
  
  static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned offset, int val)
  {
  	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
  	struct pca9532_led *led = &data->leds[offset];
  
  	if (val)
  		led->state = PCA9532_ON;
  	else
  		led->state = PCA9532_OFF;
  
  	pca9532_setled(led);
  }
  
  static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned offset)
  {
  	struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
  	unsigned char reg;
  
  	reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));
  
  	return !!(reg & (1 << (offset % 8)));
  }
  
  static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
  {
  	/* To use as input ensure pin is not driven */
  	pca9532_gpio_set_value(gc, offset, 0);
  
  	return 0;
  }
  
  static int pca9532_gpio_direction_output(struct gpio_chip *gc, unsigned offset, int val)
  {
  	pca9532_gpio_set_value(gc, offset, val);
  
  	return 0;
  }
  #endif /* CONFIG_LEDS_PCA9532_GPIO */
  
  static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)

  {
  	int i = n_devs;
  
  	if (!data)

  		return -EINVAL;

  
  	while (--i >= 0) {
  		switch (data->leds[i].type) {
  		case PCA9532_TYPE_NONE:

  		case PCA9532_TYPE_GPIO:

  			break;
  		case PCA9532_TYPE_LED:
  			led_classdev_unregister(&data->leds[i].ldev);
  			cancel_work_sync(&data->leds[i].work);
  			break;
  		case PCA9532_TYPE_N2100_BEEP:
  			if (data->idev != NULL) {
  				input_unregister_device(data->idev);
  				cancel_work_sync(&data->work);
  				data->idev = NULL;
  			}
  			break;
  		}
  	}

  
  #ifdef CONFIG_LEDS_PCA9532_GPIO
  	if (data->gpio.dev) {
  		int err = gpiochip_remove(&data->gpio);
  		if (err) {
  			dev_err(&data->client->dev, "%s failed, %d
  ",
  						"gpiochip_remove()", err);
  			return err;
  		}
  	}
  #endif
  
  	return 0;

  }

  static int pca9532_configure(struct i2c_client *client,
  	struct pca9532_data *data, struct pca9532_platform_data *pdata)
  {
  	int i, err = 0;

  	int gpios = 0;

  	u8 maxleds = data->chip_info->num_leds;

  
  	for (i = 0; i < 2; i++)	{
  		data->pwm[i] = pdata->pwm[i];
  		data->psc[i] = pdata->psc[i];

  		i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i),

  			data->pwm[i]);

  		i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i),

  			data->psc[i]);
  	}

  	for (i = 0; i < data->chip_info->num_leds; i++) {

  		struct pca9532_led *led = &data->leds[i];
  		struct pca9532_led *pled = &pdata->leds[i];
  		led->client = client;
  		led->id = i;
  		led->type = pled->type;
  		switch (led->type) {
  		case PCA9532_TYPE_NONE:
  			break;

  		case PCA9532_TYPE_GPIO:
  			gpios++;
  			break;

  		case PCA9532_TYPE_LED:
  			led->state = pled->state;

  			led->name = pled->name;

  			led->ldev.name = led->name;
  			led->ldev.brightness = LED_OFF;
  			led->ldev.brightness_set = pca9532_set_brightness;
  			led->ldev.blink_set = pca9532_set_blink;

  			INIT_WORK(&led->work, pca9532_led_work);

  			err = led_classdev_register(&client->dev, &led->ldev);
  			if (err < 0) {

  				dev_err(&client->dev,
  					"couldn't register LED %s
  ",
  					led->name);
  				goto exit;
  			}
  			pca9532_setled(led);
  			break;
  		case PCA9532_TYPE_N2100_BEEP:
  			BUG_ON(data->idev);
  			led->state = PCA9532_PWM1;
  			pca9532_setled(led);
  			data->idev = input_allocate_device();
  			if (data->idev == NULL) {
  				err = -ENOMEM;
  				goto exit;
  			}
  			data->idev->name = pled->name;
  			data->idev->phys = "i2c/pca9532";
  			data->idev->id.bustype = BUS_HOST;

  			data->idev->id.vendor = 0x001f;

  			data->idev->id.product = 0x0001;
  			data->idev->id.version = 0x0100;
  			data->idev->evbit[0] = BIT_MASK(EV_SND);
  			data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
  						BIT_MASK(SND_TONE);
  			data->idev->event = pca9532_event;
  			input_set_drvdata(data->idev, data);

  			INIT_WORK(&data->work, pca9532_input_work);

  			err = input_register_device(data->idev);
  			if (err) {
  				input_free_device(data->idev);

  				cancel_work_sync(&data->work);

  				data->idev = NULL;
  				goto exit;
  			}
  			break;
  		}
  	}

  
  #ifdef CONFIG_LEDS_PCA9532_GPIO
  	if (gpios) {
  		data->gpio.label = "gpio-pca9532";
  		data->gpio.direction_input = pca9532_gpio_direction_input;
  		data->gpio.direction_output = pca9532_gpio_direction_output;
  		data->gpio.set = pca9532_gpio_set_value;
  		data->gpio.get = pca9532_gpio_get_value;
  		data->gpio.request = pca9532_gpio_request_pin;
  		data->gpio.can_sleep = 1;
  		data->gpio.base = pdata->gpio_base;

  		data->gpio.ngpio = data->chip_info->num_leds;

  		data->gpio.dev = &client->dev;
  		data->gpio.owner = THIS_MODULE;
  
  		err = gpiochip_add(&data->gpio);
  		if (err) {
  			/* Use data->gpio.dev as a flag for freeing gpiochip */
  			data->gpio.dev = NULL;
  			dev_warn(&client->dev, "could not add gpiochip
  ");
  		} else {
  			dev_info(&client->dev, "gpios %i...%i
  ",
  				data->gpio.base, data->gpio.base +
  				data->gpio.ngpio - 1);
  		}
  	}
  #endif

  	return 0;
  
  exit:

  	pca9532_destroy_devices(data, i);

  	return err;

  }
  
  static int pca9532_probe(struct i2c_client *client,
  	const struct i2c_device_id *id)
  {
  	struct pca9532_data *data = i2c_get_clientdata(client);
  	struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;

  	int err;
  
  	if (!pca9532_pdata)
  		return -EIO;

  
  	if (!i2c_check_functionality(client->adapter,
  		I2C_FUNC_SMBUS_BYTE_DATA))
  		return -EIO;

  	data = kzalloc(sizeof(*data), GFP_KERNEL);

  	if (!data)
  		return -ENOMEM;

  	data->chip_info = &pca9532_chip_info_tbl[id->driver_data];

  	dev_info(&client->dev, "setting platform data
  ");
  	i2c_set_clientdata(client, data);
  	data->client = client;
  	mutex_init(&data->update_lock);

  	err = pca9532_configure(client, data, pca9532_pdata);

  	if (err)

  		kfree(data);

  	return err;

  }
  
  static int pca9532_remove(struct i2c_client *client)
  {
  	struct pca9532_data *data = i2c_get_clientdata(client);

  	int err;

  	err = pca9532_destroy_devices(data, data->chip_info->num_leds);

  	if (err)
  		return err;

  	kfree(data);

  	return 0;
  }
  
  static int __init pca9532_init(void)
  {
  	return i2c_add_driver(&pca9532_driver);
  }
  
  static void __exit pca9532_exit(void)
  {
  	i2c_del_driver(&pca9532_driver);
  }

  MODULE_AUTHOR("Riku Voipio");

  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("PCA 9532 LED dimmer");
  
  module_init(pca9532_init);
  module_exit(pca9532_exit);