/*
   * leds-ns2.c - Driver for the Network Space v2 (and parents) dual-GPIO LED
   *
   * Copyright (C) 2010 LaCie
   *
   * Author: Simon Guinot <sguinot@lacie.com>
   *
   * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
   *
   * 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; either version 2 of the License, or
   * (at your option) any later version.
   *
   * 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, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/gpio.h>
  #include <linux/leds.h>

  #include <linux/module.h>

  #include <mach/leds-ns2.h>
  
  /*
   * The Network Space v2 dual-GPIO LED is wired to a CPLD and can blink in
   * relation with the SATA activity. This capability is exposed through the
   * "sata" sysfs attribute.
   *
   * The following array detail the different LED registers and the combination
   * of their possible values:
   *
   *  cmd_led   |  slow_led  | /SATA active | LED state
   *            |            |              |
   *     1      |     0      |      x       |  off
   *     -      |     1      |      x       |  on
   *     0      |     0      |      1       |  on
   *     0      |     0      |      0       |  blink (rate 300ms)
   */
  
  enum ns2_led_modes {
  	NS_V2_LED_OFF,
  	NS_V2_LED_ON,
  	NS_V2_LED_SATA,
  };
  
  struct ns2_led_mode_value {
  	enum ns2_led_modes	mode;
  	int			cmd_level;
  	int			slow_level;
  };
  
  static struct ns2_led_mode_value ns2_led_modval[] = {
  	{ NS_V2_LED_OFF	, 1, 0 },
  	{ NS_V2_LED_ON	, 0, 1 },
  	{ NS_V2_LED_ON	, 1, 1 },
  	{ NS_V2_LED_SATA, 0, 0 },
  };
  
  struct ns2_led_data {
  	struct led_classdev	cdev;
  	unsigned		cmd;
  	unsigned		slow;
  	unsigned char		sata; /* True when SATA mode active. */
  	rwlock_t		rw_lock; /* Lock GPIOs. */
  };
  
  static int ns2_led_get_mode(struct ns2_led_data *led_dat,
  			    enum ns2_led_modes *mode)
  {
  	int i;
  	int ret = -EINVAL;
  	int cmd_level;
  	int slow_level;

  	read_lock_irq(&led_dat->rw_lock);

  
  	cmd_level = gpio_get_value(led_dat->cmd);
  	slow_level = gpio_get_value(led_dat->slow);
  
  	for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
  		if (cmd_level == ns2_led_modval[i].cmd_level &&
  		    slow_level == ns2_led_modval[i].slow_level) {
  			*mode = ns2_led_modval[i].mode;
  			ret = 0;
  			break;
  		}
  	}

  	read_unlock_irq(&led_dat->rw_lock);

  
  	return ret;
  }
  
  static void ns2_led_set_mode(struct ns2_led_data *led_dat,
  			     enum ns2_led_modes mode)
  {
  	int i;

  	unsigned long flags;

  	write_lock_irqsave(&led_dat->rw_lock, flags);

  
  	for (i = 0; i < ARRAY_SIZE(ns2_led_modval); i++) {
  		if (mode == ns2_led_modval[i].mode) {
  			gpio_set_value(led_dat->cmd,
  				       ns2_led_modval[i].cmd_level);
  			gpio_set_value(led_dat->slow,
  				       ns2_led_modval[i].slow_level);
  		}
  	}

  	write_unlock_irqrestore(&led_dat->rw_lock, flags);

  }
  
  static void ns2_led_set(struct led_classdev *led_cdev,
  			enum led_brightness value)
  {
  	struct ns2_led_data *led_dat =
  		container_of(led_cdev, struct ns2_led_data, cdev);
  	enum ns2_led_modes mode;
  
  	if (value == LED_OFF)
  		mode = NS_V2_LED_OFF;
  	else if (led_dat->sata)
  		mode = NS_V2_LED_SATA;
  	else
  		mode = NS_V2_LED_ON;
  
  	ns2_led_set_mode(led_dat, mode);
  }
  
  static ssize_t ns2_led_sata_store(struct device *dev,
  				  struct device_attribute *attr,
  				  const char *buff, size_t count)
  {

  	struct led_classdev *led_cdev = dev_get_drvdata(dev);
  	struct ns2_led_data *led_dat =
  		container_of(led_cdev, struct ns2_led_data, cdev);

  	int ret;
  	unsigned long enable;
  	enum ns2_led_modes mode;

  
  	ret = strict_strtoul(buff, 10, &enable);
  	if (ret < 0)
  		return ret;
  
  	enable = !!enable;
  
  	if (led_dat->sata == enable)
  		return count;
  
  	ret = ns2_led_get_mode(led_dat, &mode);
  	if (ret < 0)
  		return ret;
  
  	if (enable && mode == NS_V2_LED_ON)
  		ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
  	if (!enable && mode == NS_V2_LED_SATA)
  		ns2_led_set_mode(led_dat, NS_V2_LED_ON);
  
  	led_dat->sata = enable;
  
  	return count;
  }
  
  static ssize_t ns2_led_sata_show(struct device *dev,
  				 struct device_attribute *attr, char *buf)
  {

  	struct led_classdev *led_cdev = dev_get_drvdata(dev);
  	struct ns2_led_data *led_dat =
  		container_of(led_cdev, struct ns2_led_data, cdev);

  
  	return sprintf(buf, "%d
  ", led_dat->sata);
  }
  
  static DEVICE_ATTR(sata, 0644, ns2_led_sata_show, ns2_led_sata_store);
  
  static int __devinit
  create_ns2_led(struct platform_device *pdev, struct ns2_led_data *led_dat,
  	       const struct ns2_led *template)
  {
  	int ret;
  	enum ns2_led_modes mode;
  
  	ret = gpio_request(template->cmd, template->name);
  	if (ret == 0) {
  		ret = gpio_direction_output(template->cmd,
  					    gpio_get_value(template->cmd));
  		if (ret)
  			gpio_free(template->cmd);
  	}
  	if (ret) {
  		dev_err(&pdev->dev, "%s: failed to setup command GPIO
  ",
  			template->name);
  	}
  
  	ret = gpio_request(template->slow, template->name);
  	if (ret == 0) {
  		ret = gpio_direction_output(template->slow,
  					    gpio_get_value(template->slow));
  		if (ret)
  			gpio_free(template->slow);
  	}
  	if (ret) {
  		dev_err(&pdev->dev, "%s: failed to setup slow GPIO
  ",
  			template->name);
  		goto err_free_cmd;
  	}
  
  	rwlock_init(&led_dat->rw_lock);
  
  	led_dat->cdev.name = template->name;
  	led_dat->cdev.default_trigger = template->default_trigger;
  	led_dat->cdev.blink_set = NULL;
  	led_dat->cdev.brightness_set = ns2_led_set;
  	led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
  	led_dat->cmd = template->cmd;
  	led_dat->slow = template->slow;
  
  	ret = ns2_led_get_mode(led_dat, &mode);
  	if (ret < 0)
  		goto err_free_slow;
  
  	/* Set LED initial state. */
  	led_dat->sata = (mode == NS_V2_LED_SATA) ? 1 : 0;
  	led_dat->cdev.brightness =
  		(mode == NS_V2_LED_OFF) ? LED_OFF : LED_FULL;
  
  	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
  	if (ret < 0)
  		goto err_free_slow;

  	ret = device_create_file(led_dat->cdev.dev, &dev_attr_sata);
  	if (ret < 0)
  		goto err_free_cdev;
  
  	return 0;
  
  err_free_cdev:
  	led_classdev_unregister(&led_dat->cdev);
  err_free_slow:
  	gpio_free(led_dat->slow);
  err_free_cmd:
  	gpio_free(led_dat->cmd);
  
  	return ret;
  }
  
  static void __devexit delete_ns2_led(struct ns2_led_data *led_dat)
  {
  	device_remove_file(led_dat->cdev.dev, &dev_attr_sata);
  	led_classdev_unregister(&led_dat->cdev);
  	gpio_free(led_dat->cmd);
  	gpio_free(led_dat->slow);
  }
  
  static int __devinit ns2_led_probe(struct platform_device *pdev)
  {
  	struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
  	struct ns2_led_data *leds_data;
  	int i;
  	int ret;
  
  	if (!pdata)
  		return -EINVAL;
  
  	leds_data = kzalloc(sizeof(struct ns2_led_data) *
  			    pdata->num_leds, GFP_KERNEL);
  	if (!leds_data)
  		return -ENOMEM;
  
  	for (i = 0; i < pdata->num_leds; i++) {
  		ret = create_ns2_led(pdev, &leds_data[i], &pdata->leds[i]);
  		if (ret < 0)
  			goto err;
  
  	}
  
  	platform_set_drvdata(pdev, leds_data);
  
  	return 0;
  
  err:
  	for (i = i - 1; i >= 0; i--)
  		delete_ns2_led(&leds_data[i]);
  
  	kfree(leds_data);
  
  	return ret;
  }
  
  static int __devexit ns2_led_remove(struct platform_device *pdev)
  {
  	int i;
  	struct ns2_led_platform_data *pdata = pdev->dev.platform_data;
  	struct ns2_led_data *leds_data;
  
  	leds_data = platform_get_drvdata(pdev);
  
  	for (i = 0; i < pdata->num_leds; i++)
  		delete_ns2_led(&leds_data[i]);
  
  	kfree(leds_data);
  	platform_set_drvdata(pdev, NULL);
  
  	return 0;
  }
  
  static struct platform_driver ns2_led_driver = {
  	.probe		= ns2_led_probe,
  	.remove		= __devexit_p(ns2_led_remove),
  	.driver		= {
  		.name	= "leds-ns2",
  		.owner	= THIS_MODULE,
  	},
  };

  module_platform_driver(ns2_led_driver);

  
  MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
  MODULE_DESCRIPTION("Network Space v2 LED driver");
  MODULE_LICENSE("GPL");

  MODULE_ALIAS("platform:leds-ns2");