/*
   * I2C access for DA9052 PMICs.
   *
   * Copyright(c) 2011 Dialog Semiconductor Ltd.
   *
   * Author: David Dajun Chen <dchen@diasemi.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.
   *
   */
  
  #include <linux/device.h>
  #include <linux/module.h>
  #include <linux/input.h>
  #include <linux/mfd/core.h>
  #include <linux/i2c.h>
  #include <linux/err.h>
  
  #include <linux/mfd/da9052/da9052.h>
  #include <linux/mfd/da9052/reg.h>
  
  #ifdef CONFIG_OF
  #include <linux/of.h>
  #include <linux/of_device.h>
  #endif
  
  /* I2C safe register check */
  static inline bool i2c_safe_reg(unsigned char reg)
  {
  	switch (reg) {
  	case DA9052_STATUS_A_REG:
  	case DA9052_STATUS_B_REG:
  	case DA9052_STATUS_C_REG:
  	case DA9052_STATUS_D_REG:
  	case DA9052_ADC_RES_L_REG:
  	case DA9052_ADC_RES_H_REG:
  	case DA9052_VDD_RES_REG:
  	case DA9052_ICHG_AV_REG:
  	case DA9052_TBAT_RES_REG:
  	case DA9052_ADCIN4_RES_REG:
  	case DA9052_ADCIN5_RES_REG:
  	case DA9052_ADCIN6_RES_REG:
  	case DA9052_TJUNC_RES_REG:
  	case DA9052_TSI_X_MSB_REG:
  	case DA9052_TSI_Y_MSB_REG:
  	case DA9052_TSI_LSB_REG:
  	case DA9052_TSI_Z_MSB_REG:
  		return true;
  	default:
  		return false;
  	}
  }
  
  /*
   * There is an issue with DA9052 and DA9053_AA/BA/BB PMIC where the PMIC
   * gets lockup up or fails to respond following a system reset.
   * This fix is to follow any read or write with a dummy read to a safe
   * register.
   */
  static int da9052_i2c_fix(struct da9052 *da9052, unsigned char reg)
  {
  	int val;
  
  	switch (da9052->chip_id) {
  	case DA9052:
  	case DA9053_AA:
  	case DA9053_BA:
  	case DA9053_BB:
  		/* A dummy read to a safe register address. */
  	if (!i2c_safe_reg(reg))
  			return regmap_read(da9052->regmap,
  					   DA9052_PARK_REGISTER,
  					   &val);
  		break;
  	default:
  		/*
  		 * For other chips parking of I2C register
  		 * to a safe place is not required.
  		 */
  		break;
  	}
  
  	return 0;
  }
  
  /*
   * According to errata item 24, multiwrite mode should be avoided
   * in order to prevent register data corruption after power-down.
   */
  static int da9052_i2c_disable_multiwrite(struct da9052 *da9052)
  {
  	int reg_val, ret;
  
  	ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, &reg_val);
  	if (ret < 0)
  		return ret;
  
  	if (!(reg_val & DA9052_CONTROL_B_WRITEMODE)) {
  		reg_val |= DA9052_CONTROL_B_WRITEMODE;
  		ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
  				   reg_val);
  		if (ret < 0)
  			return ret;
  	}
  
  	return 0;
  }
  
  static const struct i2c_device_id da9052_i2c_id[] = {
  	{"da9052", DA9052},
  	{"da9053-aa", DA9053_AA},
  	{"da9053-ba", DA9053_BA},
  	{"da9053-bb", DA9053_BB},
  	{}
  };
  
  #ifdef CONFIG_OF
  static const struct of_device_id dialog_dt_ids[] = {
  	{ .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
  	{ .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
  	{ .compatible = "dlg,da9053-ab", .data = &da9052_i2c_id[2] },
  	{ .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
  	{ /* sentinel */ }
  };
  #endif
  
  static int da9052_i2c_probe(struct i2c_client *client,
  				       const struct i2c_device_id *id)
  {
  	struct da9052 *da9052;
  	int ret;
  
  	da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
  	if (!da9052)
  		return -ENOMEM;
  
  	if (!i2c_check_functionality(client->adapter,
  				     I2C_FUNC_SMBUS_BYTE_DATA)) {
  		dev_info(&client->dev, "Error in %s:i2c_check_functionality
  ",
  			 __func__);
  		return  -ENODEV;
  	}
  
  	da9052->dev = &client->dev;
  	da9052->chip_irq = client->irq;
  	da9052->fix_io = da9052_i2c_fix;
  
  	i2c_set_clientdata(client, da9052);
  
  	da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
  	if (IS_ERR(da9052->regmap)) {
  		ret = PTR_ERR(da9052->regmap);
  		dev_err(&client->dev, "Failed to allocate register map: %d
  ",
  			ret);
  		return ret;
  	}
  
  	ret = da9052_i2c_disable_multiwrite(da9052);
  	if (ret < 0)
  		return ret;
  
  #ifdef CONFIG_OF
  	if (!id) {
  		struct device_node *np = client->dev.of_node;
  		const struct of_device_id *deviceid;
  
  		deviceid = of_match_node(dialog_dt_ids, np);
  		id = deviceid->data;
  	}
  #endif
  
  	if (!id) {
  		ret = -ENODEV;
  		dev_err(&client->dev, "id is null.
  ");
  		return ret;
  	}
  
  	ret = da9052_device_init(da9052, id->driver_data);
  	if (ret != 0)
  		return ret;
  
  	return 0;
  }
  
  static int da9052_i2c_remove(struct i2c_client *client)
  {
  	struct da9052 *da9052 = i2c_get_clientdata(client);
  
  	da9052_device_exit(da9052);
  	return 0;
  }
  
  static struct i2c_driver da9052_i2c_driver = {
  	.probe = da9052_i2c_probe,
  	.remove = da9052_i2c_remove,
  	.id_table = da9052_i2c_id,
  	.driver = {
  		.name = "da9052",
  		.owner = THIS_MODULE,
  #ifdef CONFIG_OF
  		.of_match_table = dialog_dt_ids,
  #endif
  	},
  };
  
  static int __init da9052_i2c_init(void)
  {
  	int ret;
  
  	ret = i2c_add_driver(&da9052_i2c_driver);
  	if (ret != 0) {
  		pr_err("DA9052 I2C registration failed %d
  ", ret);
  		return ret;
  	}
  
  	return 0;
  }
  subsys_initcall(da9052_i2c_init);
  
  static void __exit da9052_i2c_exit(void)
  {
  	i2c_del_driver(&da9052_i2c_driver);
  }
  module_exit(da9052_i2c_exit);
  
  MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
  MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
  MODULE_LICENSE("GPL");