// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Core driver for the generic 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>

   */
  
  #define pr_fmt(fmt) "generic 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/pinctrl/pinctrl.h>
  #include <linux/pinctrl/pinconf.h>
  #include <linux/pinctrl/pinconf-generic.h>

  #include <linux/of.h>

  #include "core.h"
  #include "pinconf.h"

  #include "pinctrl-utils.h"

  
  #ifdef CONFIG_DEBUG_FS

  static const struct pin_config_item conf_items[] = {

  	PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),

  	PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
  	PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),

  	PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", NULL, false),

  	PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,

  				"input bias pull to pin specific state", NULL, false),

  	PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", NULL, false),

  	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
  	PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),

  	PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),

  	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),

  	PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),

  	PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),

  	PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),

  	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),

  	PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),

  	PCONFDUMP(PIN_CONFIG_LOW_POWER_MODE, "pin low power", "mode", true),

  	PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),

  	PCONFDUMP(PIN_CONFIG_OUTPUT, "pin output", "level", true),

  	PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),

  	PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),

  	PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),

  	PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),

  };

  static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
  				     struct seq_file *s, const char *gname,
  				     unsigned pin,
  				     const struct pin_config_item *items,

  				     int nitems, int *print_sep)

  {

  	int i;

  	for (i = 0; i < nitems; i++) {

  		unsigned long config;
  		int ret;
  
  		/* We want to check out this parameter */

  		config = pinconf_to_config_packed(items[i].param, 0);
  		if (gname)
  			ret = pin_config_group_get(dev_name(pctldev->dev),
  						   gname, &config);
  		else
  			ret = pin_config_get_for_pin(pctldev, pin, &config);

  		/* These are legal errors */
  		if (ret == -EINVAL || ret == -ENOTSUPP)
  			continue;
  		if (ret) {
  			seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
  			continue;
  		}

  		/* comma between multiple configs */
  		if (*print_sep)
  			seq_puts(s, ", ");
  		*print_sep = 1;

  		seq_puts(s, items[i].display);

  		/* Print unit if available */

  		if (items[i].has_arg) {

  			seq_printf(s, " (%u",
  				   pinconf_to_config_argument(config));

  			if (items[i].format)
  				seq_printf(s, " %s)", items[i].format);

  			else
  				seq_puts(s, ")");
  		}

  	}
  }

  /**
   * pinconf_generic_dump_pins - Print information about pin or group of pins
   * @pctldev:	Pincontrol device
   * @s:		File to print to
   * @gname:	Group name specifying pins
   * @pin:	Pin number specyfying pin
   *
   * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
   * specified either by pin using @pin or by group using @gname. Only one needs
   * to be specified the other can be NULL/0.
   */
  void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
  			       const char *gname, unsigned pin)

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

  	int print_sep = 0;

  
  	if (!ops->is_generic)
  		return;

  	/* generic parameters */
  	pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,

  				 ARRAY_SIZE(conf_items), &print_sep);

  	/* driver-specific parameters */

  	if (pctldev->desc->num_custom_params &&
  	    pctldev->desc->custom_conf_items)

  		pinconf_generic_dump_one(pctldev, s, gname, pin,

  					 pctldev->desc->custom_conf_items,

  					 pctldev->desc->num_custom_params,
  					 &print_sep);

  }

  void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
  				 struct seq_file *s, unsigned long config)
  {
  	int i;

  	for (i = 0; i < ARRAY_SIZE(conf_items); i++) {

  		if (pinconf_to_config_param(config) != conf_items[i].param)
  			continue;
  		seq_printf(s, "%s: 0x%x", conf_items[i].display,
  			   pinconf_to_config_argument(config));
  	}

  	if (!pctldev->desc->num_custom_params ||
  	    !pctldev->desc->custom_conf_items)

  		return;

  	for (i = 0; i < pctldev->desc->num_custom_params; i++) {
  		if (pinconf_to_config_param(config) !=
  		    pctldev->desc->custom_conf_items[i].param)

  			continue;

  		seq_printf(s, "%s: 0x%x",
  				pctldev->desc->custom_conf_items[i].display,
  				pinconf_to_config_argument(config));

  	}

  }
  EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);

  #endif

  
  #ifdef CONFIG_OF

  static const struct pinconf_generic_params dt_params[] = {

  	{ "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },

  	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
  	{ "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },

  	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },

  	{ "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },

  	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },

  	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
  	{ "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },

  	{ "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },

  	{ "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },

  	{ "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },

  	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },

  	{ "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },

  	{ "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },

  	{ "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },

  	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },

  	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },

  	{ "low-power-disable", PIN_CONFIG_LOW_POWER_MODE, 0 },

  	{ "low-power-enable", PIN_CONFIG_LOW_POWER_MODE, 1 },

  	{ "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
  	{ "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },

  	{ "output-high", PIN_CONFIG_OUTPUT, 1, },

  	{ "output-low", PIN_CONFIG_OUTPUT, 0, },
  	{ "power-source", PIN_CONFIG_POWER_SOURCE, 0 },

  	{ "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },

  	{ "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },

  	{ "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },

  };
  
  /**

   * parse_dt_cfg() - Parse DT pinconf parameters

   * @np:	DT node

   * @params:	Array of describing generic parameters

   * @count:	Number of entries in @params
   * @cfg:	Array of parsed config options
   * @ncfg:	Number of entries in @cfg
   *
   * Parse the config options described in @params from @np and puts the result

   * in @cfg. @cfg does not need to be empty, entries are added beginning at

   * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
   * needs to have enough memory allocated to hold all possible entries.
   */
  static void parse_dt_cfg(struct device_node *np,

  			 const struct pinconf_generic_params *params,

  			 unsigned int count, unsigned long *cfg,
  			 unsigned int *ncfg)
  {
  	int i;
  
  	for (i = 0; i < count; i++) {
  		u32 val;
  		int ret;

  		const struct pinconf_generic_params *par = &params[i];

  
  		ret = of_property_read_u32(np, par->property, &val);
  
  		/* property not found */
  		if (ret == -EINVAL)
  			continue;
  
  		/* use default value, when no value is specified */
  		if (ret)
  			val = par->default_value;
  
  		pr_debug("found %s with value %u
  ", par->property, val);
  		cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
  		(*ncfg)++;
  	}
  }
  
  /**

   * pinconf_generic_parse_dt_config()
   * parse the config properties into generic pinconfig values.
   * @np: node containing the pinconfig properties
   * @configs: array with nconfigs entries containing the generic pinconf values

   *           must be freed when no longer necessary.

   * @nconfigs: umber of configurations
   */
  int pinconf_generic_parse_dt_config(struct device_node *np,

  				    struct pinctrl_dev *pctldev,

  				    unsigned long **configs,
  				    unsigned int *nconfigs)
  {

  	unsigned long *cfg;

  	unsigned int max_cfg, ncfg = 0;

  	int ret;

  
  	if (!np)
  		return -EINVAL;

  	/* allocate a temporary array big enough to hold one of each option */

  	max_cfg = ARRAY_SIZE(dt_params);
  	if (pctldev)

  		max_cfg += pctldev->desc->num_custom_params;

  	cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);

  	if (!cfg)
  		return -ENOMEM;

  	parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);

  	if (pctldev && pctldev->desc->num_custom_params &&
  		pctldev->desc->custom_params)
  		parse_dt_cfg(np, pctldev->desc->custom_params,
  			     pctldev->desc->num_custom_params, cfg, &ncfg);

  	ret = 0;

  	/* no configs found at all */
  	if (ncfg == 0) {
  		*configs = NULL;
  		*nconfigs = 0;

  		goto out;

  	}

  	/*
  	 * Now limit the number of configs to the real number of
  	 * found properties.
  	 */

  	*configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);

  	if (!*configs) {
  		ret = -ENOMEM;
  		goto out;
  	}

  	*nconfigs = ncfg;

  
  out:
  	kfree(cfg);
  	return ret;

  }

  
  int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
  		struct device_node *np, struct pinctrl_map **map,

  		unsigned *reserved_maps, unsigned *num_maps,
  		enum pinctrl_map_type type)

  {
  	int ret;
  	const char *function;
  	struct device *dev = pctldev->dev;
  	unsigned long *configs = NULL;
  	unsigned num_configs = 0;

  	unsigned reserve, strings_count;

  	struct property *prop;
  	const char *group;

  	const char *subnode_target_type = "pins";

  	ret = of_property_count_strings(np, "pins");
  	if (ret < 0) {
  		ret = of_property_count_strings(np, "groups");
  		if (ret < 0)
  			/* skip this node; may contain config child nodes */
  			return 0;
  		if (type == PIN_MAP_TYPE_INVALID)
  			type = PIN_MAP_TYPE_CONFIGS_GROUP;
  		subnode_target_type = "groups";
  	} else {
  		if (type == PIN_MAP_TYPE_INVALID)
  			type = PIN_MAP_TYPE_CONFIGS_PIN;
  	}
  	strings_count = ret;

  	ret = of_property_read_string(np, "function", &function);
  	if (ret < 0) {
  		/* EINVAL=missing, which is fine since it's optional */
  		if (ret != -EINVAL)

  			dev_err(dev, "%pOF: could not parse property function
  ",
  				np);

  		function = NULL;
  	}

  	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
  					      &num_configs);

  	if (ret < 0) {

  		dev_err(dev, "%pOF: could not parse node property
  ", np);

  		return ret;
  	}
  
  	reserve = 0;
  	if (function != NULL)
  		reserve++;
  	if (num_configs)
  		reserve++;

  	reserve *= strings_count;

  
  	ret = pinctrl_utils_reserve_map(pctldev, map, reserved_maps,
  			num_maps, reserve);
  	if (ret < 0)
  		goto exit;

  	of_property_for_each_string(np, subnode_target_type, prop, group) {

  		if (function) {
  			ret = pinctrl_utils_add_map_mux(pctldev, map,
  					reserved_maps, num_maps, group,
  					function);
  			if (ret < 0)
  				goto exit;
  		}
  
  		if (num_configs) {
  			ret = pinctrl_utils_add_map_configs(pctldev, map,
  					reserved_maps, num_maps, group, configs,

  					num_configs, type);

  			if (ret < 0)
  				goto exit;
  		}
  	}
  	ret = 0;
  
  exit:
  	kfree(configs);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);
  
  int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
  		struct device_node *np_config, struct pinctrl_map **map,

  		unsigned *num_maps, enum pinctrl_map_type type)

  {
  	unsigned reserved_maps;
  	struct device_node *np;
  	int ret;
  
  	reserved_maps = 0;
  	*map = NULL;
  	*num_maps = 0;

  	ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
  						&reserved_maps, num_maps, type);
  	if (ret < 0)
  		goto exit;

  	for_each_available_child_of_node(np_config, np) {

  		ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,

  					&reserved_maps, num_maps, type);

  		if (ret < 0)
  			goto exit;

  	}
  	return 0;

  
  exit:

  	pinctrl_utils_free_map(pctldev, *map, *num_maps);

  	return ret;

  }
  EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);

  void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
  				 struct pinctrl_map *map,
  				 unsigned num_maps)
  {
  	pinctrl_utils_free_map(pctldev, map, num_maps);
  }
  EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);

  #endif