/*
   * drivers/mfd/si476x-prop.c -- Subroutines to access
   * properties of si476x chips
   *
   * Copyright (C) 2012 Innovative Converged Devices(ICD)
   * Copyright (C) 2013 Andrey Smirnov
   *
   * Author: Andrey Smirnov <andrew.smirnov@gmail.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; version 2 of the License.
   *
   * 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.
   */
  #include <linux/module.h>
  
  #include <linux/mfd/si476x-core.h>
  
  struct si476x_property_range {
  	u16 low, high;
  };
  
  static bool si476x_core_element_is_in_array(u16 element,
  					    const u16 array[],
  					    size_t size)
  {
  	int i;
  
  	for (i = 0; i < size; i++)
  		if (element == array[i])
  			return true;
  
  	return false;
  }
  
  static bool si476x_core_element_is_in_range(u16 element,
  					    const struct si476x_property_range range[],
  					    size_t size)
  {
  	int i;
  
  	for (i = 0; i < size; i++)
  		if (element <= range[i].high && element >= range[i].low)
  			return true;
  
  	return false;
  }
  
  static bool si476x_core_is_valid_property_a10(struct si476x_core *core,
  					      u16 property)
  {
  	static const u16 valid_properties[] = {
  		0x0000,
  		0x0500, 0x0501,
  		0x0600,
  		0x0709, 0x070C, 0x070D, 0x70E, 0x710,
  		0x0718,
  		0x1207, 0x1208,
  		0x2007,
  		0x2300,
  	};
  
  	static const struct si476x_property_range valid_ranges[] = {
  		{ 0x0200, 0x0203 },
  		{ 0x0300, 0x0303 },
  		{ 0x0400, 0x0404 },
  		{ 0x0700, 0x0707 },
  		{ 0x1100, 0x1102 },
  		{ 0x1200, 0x1204 },
  		{ 0x1300, 0x1306 },
  		{ 0x2000, 0x2005 },
  		{ 0x2100, 0x2104 },
  		{ 0x2106, 0x2106 },
  		{ 0x2200, 0x220E },
  		{ 0x3100, 0x3104 },
  		{ 0x3207, 0x320F },
  		{ 0x3300, 0x3304 },
  		{ 0x3500, 0x3517 },
  		{ 0x3600, 0x3617 },
  		{ 0x3700, 0x3717 },
  		{ 0x4000, 0x4003 },
  	};
  
  	return	si476x_core_element_is_in_range(property, valid_ranges,
  						ARRAY_SIZE(valid_ranges)) ||
  		si476x_core_element_is_in_array(property, valid_properties,
  						ARRAY_SIZE(valid_properties));
  }
  
  static bool si476x_core_is_valid_property_a20(struct si476x_core *core,
  					      u16 property)
  {
  	static const u16 valid_properties[] = {
  		0x071B,
  		0x1006,
  		0x2210,
  		0x3401,
  	};
  
  	static const struct si476x_property_range valid_ranges[] = {
  		{ 0x2215, 0x2219 },
  	};
  
  	return	si476x_core_is_valid_property_a10(core, property) ||
  		si476x_core_element_is_in_range(property, valid_ranges,
  						ARRAY_SIZE(valid_ranges))  ||
  		si476x_core_element_is_in_array(property, valid_properties,
  						ARRAY_SIZE(valid_properties));
  }
  
  static bool si476x_core_is_valid_property_a30(struct si476x_core *core,
  					      u16 property)
  {
  	static const u16 valid_properties[] = {
  		0x071C, 0x071D,
  		0x1007, 0x1008,
  		0x220F, 0x2214,
  		0x2301,
  		0x3105, 0x3106,
  		0x3402,
  	};
  
  	static const struct si476x_property_range valid_ranges[] = {
  		{ 0x0405, 0x0411 },
  		{ 0x2008, 0x200B },
  		{ 0x2220, 0x2223 },
  		{ 0x3100, 0x3106 },
  	};
  
  	return	si476x_core_is_valid_property_a20(core, property) ||
  		si476x_core_element_is_in_range(property, valid_ranges,
  						ARRAY_SIZE(valid_ranges)) ||
  		si476x_core_element_is_in_array(property, valid_properties,
  						ARRAY_SIZE(valid_properties));
  }
  
  typedef bool (*valid_property_pred_t) (struct si476x_core *, u16);
  
  static bool si476x_core_is_valid_property(struct si476x_core *core,
  					  u16 property)
  {
  	static const valid_property_pred_t is_valid_property[] = {
  		[SI476X_REVISION_A10] = si476x_core_is_valid_property_a10,
  		[SI476X_REVISION_A20] = si476x_core_is_valid_property_a20,
  		[SI476X_REVISION_A30] = si476x_core_is_valid_property_a30,
  	};
  
  	BUG_ON(core->revision > SI476X_REVISION_A30 ||
  	       core->revision == -1);
  	return is_valid_property[core->revision](core, property);
  }
  
  
  static bool si476x_core_is_readonly_property(struct si476x_core *core,
  					     u16 property)
  {
  	BUG_ON(core->revision > SI476X_REVISION_A30 ||
  	       core->revision == -1);
  
  	switch (core->revision) {
  	case SI476X_REVISION_A10:
  		return (property == 0x3200);
  	case SI476X_REVISION_A20:
  		return (property == 0x1006 ||
  			property == 0x2210 ||
  			property == 0x3200);
  	case SI476X_REVISION_A30:
  		return false;
  	}
  
  	return false;
  }
  
  static bool si476x_core_regmap_readable_register(struct device *dev,
  						 unsigned int reg)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct si476x_core *core = i2c_get_clientdata(client);
  
  	return si476x_core_is_valid_property(core, (u16) reg);
  
  }
  
  static bool si476x_core_regmap_writable_register(struct device *dev,
  						 unsigned int reg)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct si476x_core *core = i2c_get_clientdata(client);
  
  	return si476x_core_is_valid_property(core, (u16) reg) &&
  		!si476x_core_is_readonly_property(core, (u16) reg);
  }
  
  
  static int si476x_core_regmap_write(void *context, unsigned int reg,
  				    unsigned int val)
  {
  	return si476x_core_cmd_set_property(context, reg, val);
  }
  
  static int si476x_core_regmap_read(void *context, unsigned int reg,
  				   unsigned *val)
  {
  	struct si476x_core *core = context;
  	int err;
  
  	err = si476x_core_cmd_get_property(core, reg);
  	if (err < 0)
  		return err;
  
  	*val = err;
  
  	return 0;
  }
  
  
  static const struct regmap_config si476x_regmap_config = {
  	.reg_bits = 16,
  	.val_bits = 16,
  
  	.max_register = 0x4003,
  
  	.writeable_reg = si476x_core_regmap_writable_register,
  	.readable_reg = si476x_core_regmap_readable_register,
  
  	.reg_read = si476x_core_regmap_read,
  	.reg_write = si476x_core_regmap_write,
  
  	.cache_type = REGCACHE_RBTREE,
  };
  
  struct regmap *devm_regmap_init_si476x(struct si476x_core *core)
  {
  	return devm_regmap_init(&core->client->dev, NULL,
  				core, &si476x_regmap_config);
  }
  EXPORT_SYMBOL_GPL(devm_regmap_init_si476x);