/*
   * Core driver for the pin config portions of the pin control subsystem
   *
   * Copyright (C) 2011 ST-Ericsson SA
   * Written on behalf of Linaro for ST-Ericsson
   *
   * Author: Linus Walleij <linus.walleij@linaro.org>
   *
   * License terms: GNU General Public License (GPL) version 2
   */
  #define pr_fmt(fmt) "pinconfig core: " fmt
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/device.h>
  #include <linux/slab.h>
  #include <linux/debugfs.h>
  #include <linux/seq_file.h>

  #include <linux/uaccess.h>

  #include <linux/pinctrl/machine.h>
  #include <linux/pinctrl/pinctrl.h>
  #include <linux/pinctrl/pinconf.h>
  #include "core.h"
  #include "pinconf.h"

  int pinconf_check_ops(struct pinctrl_dev *pctldev)
  {
  	const struct pinconf_ops *ops = pctldev->desc->confops;

  	/* We have to be able to config the pins in SOME way */

  	if (!ops->pin_config_set && !ops->pin_config_group_set) {
  		dev_err(pctldev->dev,
  			"pinconf has to be able to set a pins config
  ");

  		return -EINVAL;

  	}

  	return 0;
  }

  int pinconf_validate_map(const struct pinctrl_map *map, int i)

  {
  	if (!map->data.configs.group_or_pin) {
  		pr_err("failed to register map %s (%d): no group/pin given
  ",
  		       map->name, i);
  		return -EINVAL;
  	}

  	if (!map->data.configs.num_configs ||

  			!map->data.configs.configs) {

  		pr_err("failed to register map %s (%d): no configs given
  ",

  		       map->name, i);
  		return -EINVAL;
  	}
  
  	return 0;
  }

  int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,

  			   unsigned long *config)
  {
  	const struct pinconf_ops *ops = pctldev->desc->confops;
  
  	if (!ops || !ops->pin_config_get) {

  		dev_dbg(pctldev->dev,
  			"cannot get pin configuration, .pin_config_get missing in driver
  ");

  		return -ENOTSUPP;

  	}
  
  	return ops->pin_config_get(pctldev, pin, config);
  }

  int pin_config_group_get(const char *dev_name, const char *pin_group,

  			 unsigned long *config)
  {

  	struct pinctrl_dev *pctldev;
  	const struct pinconf_ops *ops;

  	int selector, ret;

  	pctldev = get_pinctrl_dev_from_devname(dev_name);

  	if (!pctldev) {
  		ret = -EINVAL;

  		return ret;

  	}

  
  	mutex_lock(&pctldev->mutex);

  	ops = pctldev->desc->confops;

  	if (!ops || !ops->pin_config_group_get) {

  		dev_dbg(pctldev->dev,
  			"cannot get configuration for pin group, missing group config get function in driver
  ");

  		ret = -ENOTSUPP;

  		goto unlock;

  	}
  
  	selector = pinctrl_get_group_selector(pctldev, pin_group);

  	if (selector < 0) {
  		ret = selector;
  		goto unlock;
  	}

  	ret = ops->pin_config_group_get(pctldev, selector, config);
  
  unlock:

  	mutex_unlock(&pctldev->mutex);

  	return ret;

  }

  int pinconf_map_to_setting(const struct pinctrl_map *map,

  			  struct pinctrl_setting *setting)
  {
  	struct pinctrl_dev *pctldev = setting->pctldev;

  	int pin;

  
  	switch (setting->type) {
  	case PIN_MAP_TYPE_CONFIGS_PIN:

  		pin = pin_get_from_name(pctldev,
  					map->data.configs.group_or_pin);
  		if (pin < 0) {
  			dev_err(pctldev->dev, "could not map pin config for \"%s\"",
  				map->data.configs.group_or_pin);
  			return pin;
  		}
  		setting->data.configs.group_or_pin = pin;

  		break;
  	case PIN_MAP_TYPE_CONFIGS_GROUP:

  		pin = pinctrl_get_group_selector(pctldev,
  					 map->data.configs.group_or_pin);
  		if (pin < 0) {
  			dev_err(pctldev->dev, "could not map group config for \"%s\"",
  				map->data.configs.group_or_pin);
  			return pin;
  		}
  		setting->data.configs.group_or_pin = pin;

  		break;
  	default:
  		return -EINVAL;
  	}
  
  	setting->data.configs.num_configs = map->data.configs.num_configs;
  	setting->data.configs.configs = map->data.configs.configs;
  
  	return 0;
  }

  void pinconf_free_setting(const struct pinctrl_setting *setting)

  {
  }

  int pinconf_apply_setting(const struct pinctrl_setting *setting)

  {
  	struct pinctrl_dev *pctldev = setting->pctldev;
  	const struct pinconf_ops *ops = pctldev->desc->confops;

  	int ret;

  
  	if (!ops) {
  		dev_err(pctldev->dev, "missing confops
  ");
  		return -EINVAL;
  	}
  
  	switch (setting->type) {
  	case PIN_MAP_TYPE_CONFIGS_PIN:
  		if (!ops->pin_config_set) {
  			dev_err(pctldev->dev, "missing pin_config_set op
  ");
  			return -EINVAL;
  		}

  		ret = ops->pin_config_set(pctldev,
  				setting->data.configs.group_or_pin,
  				setting->data.configs.configs,
  				setting->data.configs.num_configs);
  		if (ret < 0) {
  			dev_err(pctldev->dev,
  				"pin_config_set op failed for pin %d
  ",
  				setting->data.configs.group_or_pin);
  			return ret;

  		}
  		break;
  	case PIN_MAP_TYPE_CONFIGS_GROUP:
  		if (!ops->pin_config_group_set) {
  			dev_err(pctldev->dev,
  				"missing pin_config_group_set op
  ");
  			return -EINVAL;
  		}

  		ret = ops->pin_config_group_set(pctldev,
  				setting->data.configs.group_or_pin,
  				setting->data.configs.configs,
  				setting->data.configs.num_configs);
  		if (ret < 0) {
  			dev_err(pctldev->dev,
  				"pin_config_group_set op failed for group %d
  ",
  				setting->data.configs.group_or_pin);
  			return ret;

  		}
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }

  int pinconf_set_config(struct pinctrl_dev *pctldev, unsigned pin,
  		       unsigned long *configs, size_t nconfigs)
  {
  	const struct pinconf_ops *ops;
  
  	ops = pctldev->desc->confops;

  	if (!ops || !ops->pin_config_set)

  		return -ENOTSUPP;
  
  	return ops->pin_config_set(pctldev, pin, configs, nconfigs);
  }

  #ifdef CONFIG_DEBUG_FS

  static void pinconf_show_config(struct seq_file *s, struct pinctrl_dev *pctldev,

  		      unsigned long *configs, unsigned num_configs)

  {

  	const struct pinconf_ops *confops;

  	int i;

  	if (pctldev)
  		confops = pctldev->desc->confops;
  	else
  		confops = NULL;

  	for (i = 0; i < num_configs; i++) {
  		seq_puts(s, "config ");
  		if (confops && confops->pin_config_config_dbg_show)
  			confops->pin_config_config_dbg_show(pctldev, s,
  							    configs[i]);
  		else
  			seq_printf(s, "%08lx", configs[i]);

  		seq_putc(s, '
  ');

  	}
  }

  void pinconf_show_map(struct seq_file *s, const struct pinctrl_map *map)

  {
  	struct pinctrl_dev *pctldev;
  
  	pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);

  	switch (map->type) {
  	case PIN_MAP_TYPE_CONFIGS_PIN:

  		seq_puts(s, "pin ");

  		break;
  	case PIN_MAP_TYPE_CONFIGS_GROUP:

  		seq_puts(s, "group ");

  		break;
  	default:
  		break;
  	}
  
  	seq_printf(s, "%s
  ", map->data.configs.group_or_pin);

  	pinconf_show_config(s, pctldev, map->data.configs.configs,
  			    map->data.configs.num_configs);

  }
  
  void pinconf_show_setting(struct seq_file *s,

  			  const struct pinctrl_setting *setting)

  {
  	struct pinctrl_dev *pctldev = setting->pctldev;
  	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
  	struct pin_desc *desc;

  
  	switch (setting->type) {
  	case PIN_MAP_TYPE_CONFIGS_PIN:
  		desc = pin_desc_get(setting->pctldev,
  				    setting->data.configs.group_or_pin);

  		seq_printf(s, "pin %s (%d)", desc->name,

  			   setting->data.configs.group_or_pin);
  		break;
  	case PIN_MAP_TYPE_CONFIGS_GROUP:
  		seq_printf(s, "group %s (%d)",
  			   pctlops->get_group_name(pctldev,
  					setting->data.configs.group_or_pin),
  			   setting->data.configs.group_or_pin);
  		break;
  	default:
  		break;
  	}
  
  	/*

  	 * FIXME: We should really get the pin controller to dump the config

  	 * values, so they can be decoded to something meaningful.
  	 */

  	pinconf_show_config(s, pctldev, setting->data.configs.configs,
  			    setting->data.configs.num_configs);

  }

  static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
  			     struct seq_file *s, int pin)
  {
  	const struct pinconf_ops *ops = pctldev->desc->confops;

  	/* no-op when not using generic pin config */

  	pinconf_generic_dump_pins(pctldev, s, NULL, pin);

  	if (ops && ops->pin_config_dbg_show)
  		ops->pin_config_dbg_show(pctldev, s, pin);
  }
  
  static int pinconf_pins_show(struct seq_file *s, void *what)
  {
  	struct pinctrl_dev *pctldev = s->private;

  	unsigned i, pin;

  
  	seq_puts(s, "Pin config settings per pin
  ");

  	seq_puts(s, "Format: pin (name): configs
  ");

  	mutex_lock(&pctldev->mutex);

  	/* The pin number can be retrived from the pin controller descriptor */

  	for (i = 0; i < pctldev->desc->npins; i++) {

  		struct pin_desc *desc;

  		pin = pctldev->desc->pins[i].number;

  		desc = pin_desc_get(pctldev, pin);

  		/* Skip if we cannot search the pin */

  		if (!desc)

  			continue;

  		seq_printf(s, "pin %d (%s): ", pin, desc->name);

  
  		pinconf_dump_pin(pctldev, s, pin);

  		seq_putc(s, '
  ');

  	}

  	mutex_unlock(&pctldev->mutex);

  	return 0;
  }
  
  static void pinconf_dump_group(struct pinctrl_dev *pctldev,
  			       struct seq_file *s, unsigned selector,
  			       const char *gname)
  {
  	const struct pinconf_ops *ops = pctldev->desc->confops;

  	/* no-op when not using generic pin config */

  	pinconf_generic_dump_pins(pctldev, s, gname, 0);

  	if (ops && ops->pin_config_group_dbg_show)
  		ops->pin_config_group_dbg_show(pctldev, s, selector);
  }
  
  static int pinconf_groups_show(struct seq_file *s, void *what)
  {
  	struct pinctrl_dev *pctldev = s->private;
  	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;

  	unsigned ngroups = pctlops->get_groups_count(pctldev);

  	unsigned selector = 0;

  	seq_puts(s, "Pin config settings per pin group
  ");

  	seq_puts(s, "Format: group (name): configs
  ");

  	while (selector < ngroups) {

  		const char *gname = pctlops->get_group_name(pctldev, selector);

  		seq_printf(s, "%u (%s): ", selector, gname);

  		pinconf_dump_group(pctldev, s, selector, gname);

  		seq_putc(s, '
  ');

  		selector++;
  	}
  
  	return 0;
  }
  
  static int pinconf_pins_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, pinconf_pins_show, inode->i_private);
  }
  
  static int pinconf_groups_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, pinconf_groups_show, inode->i_private);
  }
  
  static const struct file_operations pinconf_pins_ops = {
  	.open		= pinconf_pins_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= single_release,
  };
  
  static const struct file_operations pinconf_groups_ops = {
  	.open		= pinconf_groups_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= single_release,
  };

  #define MAX_NAME_LEN 15
  
  struct dbg_cfg {
  	enum pinctrl_map_type map_type;

  	char dev_name[MAX_NAME_LEN + 1];
  	char state_name[MAX_NAME_LEN + 1];
  	char pin_name[MAX_NAME_LEN + 1];

  };
  
  /*
   * Goal is to keep this structure as global in order to simply read the
   * pinconf-config file after a write to check config is as expected
   */
  static struct dbg_cfg pinconf_dbg_conf;
  
  /**
   * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
   * map, of the dev/pin/state that was last written to pinconf-config file.
   * @s: string filled in  with config description
   * @d: not used
   */
  static int pinconf_dbg_config_print(struct seq_file *s, void *d)
  {
  	struct pinctrl_maps *maps_node;
  	const struct pinctrl_map *map;

  	const struct pinctrl_map *found = NULL;
  	struct pinctrl_dev *pctldev;

  	struct dbg_cfg *dbg = &pinconf_dbg_conf;

  	int i;

  	mutex_lock(&pinctrl_maps_mutex);

  
  	/* Parse the pinctrl map and look for the elected pin/state */
  	for_each_maps(maps_node, i, map) {
  		if (map->type != dbg->map_type)
  			continue;
  		if (strcmp(map->dev_name, dbg->dev_name))
  			continue;
  		if (strcmp(map->name, dbg->state_name))
  			continue;

  		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
  			/* We found the right pin */
  			found = map;
  			break;

  		}
  	}
  
  	if (!found) {
  		seq_printf(s, "No config found for dev/state/pin, expected:
  ");
  		seq_printf(s, "Searched dev:%s
  ", dbg->dev_name);
  		seq_printf(s, "Searched state:%s
  ", dbg->state_name);
  		seq_printf(s, "Searched pin:%s
  ", dbg->pin_name);
  		seq_printf(s, "Use: modify config_pin <devname> "\
  				"<state> <pinname> <value>
  ");
  		goto exit;
  	}

  	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);

  	seq_printf(s, "Dev %s has config of %s in state %s:
  ",
  		   dbg->dev_name, dbg->pin_name, dbg->state_name);
  	pinconf_show_config(s, pctldev, found->data.configs.configs,
  			    found->data.configs.num_configs);

  
  exit:

  	mutex_unlock(&pinctrl_maps_mutex);

  
  	return 0;
  }
  
  /**
   * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
   * map, of a dev/pin/state entry based on user entries to pinconf-config
   * @user_buf: contains the modification request with expected format:

   *     modify <config> <devicename> <state> <name> <newvalue>

   * modify is literal string, alternatives like add/delete not supported yet

   * <config> is the configuration to be changed. Supported configs are
   *     "config_pin" or "config_group", alternatives like config_mux are not
   *     supported yet.
   * <devicename> <state> <name> are values that should match the pinctrl-maps

   * <newvalue> reflects the new config and is driver dependent

   */

  static ssize_t pinconf_dbg_config_write(struct file *file,

  	const char __user *user_buf, size_t count, loff_t *ppos)
  {
  	struct pinctrl_maps *maps_node;
  	const struct pinctrl_map *map;

  	const struct pinctrl_map *found = NULL;
  	struct pinctrl_dev *pctldev;

  	const struct pinconf_ops *confops = NULL;
  	struct dbg_cfg *dbg = &pinconf_dbg_conf;
  	const struct pinctrl_map_configs *configs;

  	char config[MAX_NAME_LEN + 1];

  	char buf[128];
  	char *b = &buf[0];
  	int buf_size;
  	char *token;
  	int i;
  
  	/* Get userspace string and assure termination */

  	buf_size = min(count, sizeof(buf) - 1);

  	if (copy_from_user(buf, user_buf, buf_size))
  		return -EFAULT;
  	buf[buf_size] = 0;
  
  	/*
  	 * need to parse entry and extract parameters:
  	 * modify configs_pin devicename state pinname newvalue
  	 */
  
  	/* Get arg: 'modify' */
  	token = strsep(&b, " ");
  	if (!token)
  		return -EINVAL;
  	if (strcmp(token, "modify"))
  		return -EINVAL;

  	/*
  	 * Get arg type: "config_pin" and "config_group"
  	 *                types are supported so far
  	 */

  	token = strsep(&b, " ");
  	if (!token)
  		return -EINVAL;

  	if (!strcmp(token, "config_pin"))
  		dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
  	else if (!strcmp(token, "config_group"))
  		dbg->map_type = PIN_MAP_TYPE_CONFIGS_GROUP;
  	else

  		return -EINVAL;

  
  	/* get arg 'device_name' */
  	token = strsep(&b, " ");

  	if (!token)

  		return -EINVAL;
  	if (strlen(token) >= MAX_NAME_LEN)
  		return -EINVAL;
  	strncpy(dbg->dev_name, token, MAX_NAME_LEN);
  
  	/* get arg 'state_name' */
  	token = strsep(&b, " ");

  	if (!token)

  		return -EINVAL;
  	if (strlen(token) >= MAX_NAME_LEN)
  		return -EINVAL;
  	strncpy(dbg->state_name, token, MAX_NAME_LEN);
  
  	/* get arg 'pin_name' */
  	token = strsep(&b, " ");

  	if (!token)

  		return -EINVAL;
  	if (strlen(token) >= MAX_NAME_LEN)
  		return -EINVAL;
  	strncpy(dbg->pin_name, token, MAX_NAME_LEN);
  
  	/* get new_value of config' */
  	token = strsep(&b, " ");

  	if (!token)

  		return -EINVAL;
  	if (strlen(token) >= MAX_NAME_LEN)
  		return -EINVAL;
  	strncpy(config, token, MAX_NAME_LEN);

  	mutex_lock(&pinctrl_maps_mutex);

  
  	/* Parse the pinctrl map and look for the selected dev/state/pin */
  	for_each_maps(maps_node, i, map) {
  		if (strcmp(map->dev_name, dbg->dev_name))
  			continue;
  		if (map->type != dbg->map_type)
  			continue;
  		if (strcmp(map->name, dbg->state_name))
  			continue;
  
  		/*  we found the right pin / state, so overwrite config */
  		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {

  			found = map;

  			break;
  		}
  	}
  
  	if (!found) {

  		count = -EINVAL;

  		goto exit;

  	}

  	pctldev = get_pinctrl_dev_from_devname(found->ctrl_dev_name);

  	if (pctldev)
  		confops = pctldev->desc->confops;
  
  	if (confops && confops->pin_config_dbg_parse_modify) {

  		configs = &found->data.configs;

  		for (i = 0; i < configs->num_configs; i++) {
  			confops->pin_config_dbg_parse_modify(pctldev,
  						     config,
  						     &configs->configs[i]);
  		}
  	}
  
  exit:

  	mutex_unlock(&pinctrl_maps_mutex);

  
  	return count;
  }
  
  static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, pinconf_dbg_config_print, inode->i_private);
  }
  
  static const struct file_operations pinconf_dbg_pinconfig_fops = {
  	.open = pinconf_dbg_config_open,
  	.write = pinconf_dbg_config_write,
  	.read = seq_read,
  	.llseek = seq_lseek,
  	.release = single_release,
  	.owner = THIS_MODULE,
  };

  void pinconf_init_device_debugfs(struct dentry *devroot,
  			 struct pinctrl_dev *pctldev)
  {
  	debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
  			    devroot, pctldev, &pinconf_pins_ops);
  	debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
  			    devroot, pctldev, &pinconf_groups_ops);

  	debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
  			    devroot, pctldev, &pinconf_dbg_pinconfig_fops);

  }
  
  #endif