/*
   * 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/platform_device.h>
  #include <linux/slab.h>
  #include <linux/gpio.h>
  #include <linux/leds.h>
  #include <linux/module.h>
  #include <linux/platform_data/leds-kirkwood-ns2.h>
  #include <linux/of.h>
  #include <linux/of_gpio.h>
  #include "leds.h"
  
  /*
   * The Network Space v2 dual-GPIO LED is wired to a CPLD. Three different LED
   * modes are available: off, on and SATA activity blinking. The LED modes are
   * controlled through two GPIOs (command and slow): each combination of values
   * for the command/slow GPIOs corresponds to a LED mode.
   */
  
  struct ns2_led_data {
  	struct led_classdev	cdev;
  	unsigned		cmd;
  	unsigned		slow;
  	bool			can_sleep;
  	int			mode_index;
  	unsigned char		sata; /* True when SATA mode active. */
  	rwlock_t		rw_lock; /* Lock GPIOs. */
  	struct work_struct	work;
  	int			num_modes;
  	struct ns2_led_modval	*modval;
  };
  
  static void ns2_led_work(struct work_struct *work)
  {
  	struct ns2_led_data *led_dat =
  		container_of(work, struct ns2_led_data, work);
  	int i = led_dat->mode_index;
  
  	gpio_set_value_cansleep(led_dat->cmd, led_dat->modval[i].cmd_level);
  	gpio_set_value_cansleep(led_dat->slow, led_dat->modval[i].slow_level);
  }
  
  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;
  
  	cmd_level = gpio_get_value_cansleep(led_dat->cmd);
  	slow_level = gpio_get_value_cansleep(led_dat->slow);
  
  	for (i = 0; i < led_dat->num_modes; i++) {
  		if (cmd_level == led_dat->modval[i].cmd_level &&
  		    slow_level == led_dat->modval[i].slow_level) {
  			*mode = led_dat->modval[i].mode;
  			ret = 0;
  			break;
  		}
  	}
  
  	return ret;
  }
  
  static void ns2_led_set_mode(struct ns2_led_data *led_dat,
  			     enum ns2_led_modes mode)
  {
  	int i;
  	bool found = false;
  	unsigned long flags;
  
  	for (i = 0; i < led_dat->num_modes; i++)
  		if (mode == led_dat->modval[i].mode) {
  			found = true;
  			break;
  		}
  
  	if (!found)
  		return;
  
  	write_lock_irqsave(&led_dat->rw_lock, flags);
  
  	if (!led_dat->can_sleep) {
  		gpio_set_value(led_dat->cmd,
  			       led_dat->modval[i].cmd_level);
  		gpio_set_value(led_dat->slow,
  			       led_dat->modval[i].slow_level);
  		goto exit_unlock;
  	}
  
  	led_dat->mode_index = i;
  	schedule_work(&led_dat->work);
  
  exit_unlock:
  	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;
  
  	ret = kstrtoul(buff, 10, &enable);
  	if (ret < 0)
  		return ret;
  
  	enable = !!enable;
  
  	if (led_dat->sata == enable)
  		goto exit;
  
  	led_dat->sata = enable;
  
  	if (!led_get_brightness(led_cdev))
  		goto exit;
  
  	if (enable)
  		ns2_led_set_mode(led_dat, NS_V2_LED_SATA);
  	else
  		ns2_led_set_mode(led_dat, NS_V2_LED_ON);
  
  exit:
  	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 struct attribute *ns2_led_attrs[] = {
  	&dev_attr_sata.attr,
  	NULL
  };
  ATTRIBUTE_GROUPS(ns2_led);
  
  static int
  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 = devm_gpio_request_one(&pdev->dev, template->cmd,
  			gpio_get_value_cansleep(template->cmd) ?
  			GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
  			template->name);
  	if (ret) {
  		dev_err(&pdev->dev, "%s: failed to setup command GPIO
  ",
  			template->name);
  		return ret;
  	}
  
  	ret = devm_gpio_request_one(&pdev->dev, template->slow,
  			gpio_get_value_cansleep(template->slow) ?
  			GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
  			template->name);
  	if (ret) {
  		dev_err(&pdev->dev, "%s: failed to setup slow GPIO
  ",
  			template->name);
  		return ret;
  	}
  
  	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->cdev.groups = ns2_led_groups;
  	led_dat->cmd = template->cmd;
  	led_dat->slow = template->slow;
  	led_dat->can_sleep = gpio_cansleep(led_dat->cmd) |
  				gpio_cansleep(led_dat->slow);
  	led_dat->modval = template->modval;
  	led_dat->num_modes = template->num_modes;
  
  	ret = ns2_led_get_mode(led_dat, &mode);
  	if (ret < 0)
  		return ret;
  
  	/* 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;
  
  	INIT_WORK(&led_dat->work, ns2_led_work);
  
  	ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  
  static void delete_ns2_led(struct ns2_led_data *led_dat)
  {
  	led_classdev_unregister(&led_dat->cdev);
  	cancel_work_sync(&led_dat->work);
  }
  
  #ifdef CONFIG_OF_GPIO
  /*
   * Translate OpenFirmware node properties into platform_data.
   */
  static int
  ns2_leds_get_of_pdata(struct device *dev, struct ns2_led_platform_data *pdata)
  {
  	struct device_node *np = dev->of_node;
  	struct device_node *child;
  	struct ns2_led *led, *leds;
  	int num_leds = 0;
  
  	num_leds = of_get_child_count(np);
  	if (!num_leds)
  		return -ENODEV;
  
  	leds = devm_kzalloc(dev, num_leds * sizeof(struct ns2_led),
  			    GFP_KERNEL);
  	if (!leds)
  		return -ENOMEM;
  
  	led = leds;
  	for_each_child_of_node(np, child) {
  		const char *string;
  		int ret, i, num_modes;
  		struct ns2_led_modval *modval;
  
  		ret = of_get_named_gpio(child, "cmd-gpio", 0);
  		if (ret < 0)
  			return ret;
  		led->cmd = ret;
  		ret = of_get_named_gpio(child, "slow-gpio", 0);
  		if (ret < 0)
  			return ret;
  		led->slow = ret;
  		ret = of_property_read_string(child, "label", &string);
  		led->name = (ret == 0) ? string : child->name;
  		ret = of_property_read_string(child, "linux,default-trigger",
  					      &string);
  		if (ret == 0)
  			led->default_trigger = string;
  
  		ret = of_property_count_u32_elems(child, "modes-map");
  		if (ret < 0 || ret % 3) {
  			dev_err(dev,
  				"Missing or malformed modes-map property
  ");
  			return -EINVAL;
  		}
  
  		num_modes = ret / 3;
  		modval = devm_kzalloc(dev,
  				      num_modes * sizeof(struct ns2_led_modval),
  				      GFP_KERNEL);
  		if (!modval)
  			return -ENOMEM;
  
  		for (i = 0; i < num_modes; i++) {
  			of_property_read_u32_index(child,
  						"modes-map", 3 * i,
  						(u32 *) &modval[i].mode);
  			of_property_read_u32_index(child,
  						"modes-map", 3 * i + 1,
  						(u32 *) &modval[i].cmd_level);
  			of_property_read_u32_index(child,
  						"modes-map", 3 * i + 2,
  						(u32 *) &modval[i].slow_level);
  		}
  
  		led->num_modes = num_modes;
  		led->modval = modval;
  
  		led++;
  	}
  
  	pdata->leds = leds;
  	pdata->num_leds = num_leds;
  
  	return 0;
  }
  
  static const struct of_device_id of_ns2_leds_match[] = {
  	{ .compatible = "lacie,ns2-leds", },
  	{},
  };
  MODULE_DEVICE_TABLE(of, of_ns2_leds_match);
  #endif /* CONFIG_OF_GPIO */
  
  struct ns2_led_priv {
  	int num_leds;
  	struct ns2_led_data leds_data[];
  };
  
  static inline int sizeof_ns2_led_priv(int num_leds)
  {
  	return sizeof(struct ns2_led_priv) +
  		      (sizeof(struct ns2_led_data) * num_leds);
  }
  
  static int ns2_led_probe(struct platform_device *pdev)
  {
  	struct ns2_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
  	struct ns2_led_priv *priv;
  	int i;
  	int ret;
  
  #ifdef CONFIG_OF_GPIO
  	if (!pdata) {
  		pdata = devm_kzalloc(&pdev->dev,
  				     sizeof(struct ns2_led_platform_data),
  				     GFP_KERNEL);
  		if (!pdata)
  			return -ENOMEM;
  
  		ret = ns2_leds_get_of_pdata(&pdev->dev, pdata);
  		if (ret)
  			return ret;
  	}
  #else
  	if (!pdata)
  		return -EINVAL;
  #endif /* CONFIG_OF_GPIO */
  
  	priv = devm_kzalloc(&pdev->dev,
  			    sizeof_ns2_led_priv(pdata->num_leds), GFP_KERNEL);
  	if (!priv)
  		return -ENOMEM;
  	priv->num_leds = pdata->num_leds;
  
  	for (i = 0; i < priv->num_leds; i++) {
  		ret = create_ns2_led(pdev, &priv->leds_data[i],
  				     &pdata->leds[i]);
  		if (ret < 0) {
  			for (i = i - 1; i >= 0; i--)
  				delete_ns2_led(&priv->leds_data[i]);
  			return ret;
  		}
  	}
  
  	platform_set_drvdata(pdev, priv);
  
  	return 0;
  }
  
  static int ns2_led_remove(struct platform_device *pdev)
  {
  	int i;
  	struct ns2_led_priv *priv;
  
  	priv = platform_get_drvdata(pdev);
  
  	for (i = 0; i < priv->num_leds; i++)
  		delete_ns2_led(&priv->leds_data[i]);
  
  	return 0;
  }
  
  static struct platform_driver ns2_led_driver = {
  	.probe		= ns2_led_probe,
  	.remove		= ns2_led_remove,
  	.driver		= {
  		.name		= "leds-ns2",
  		.of_match_table	= of_match_ptr(of_ns2_leds_match),
  	},
  };
  
  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");