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

  /*
   * AS3711 PMIC MFC driver
   *
   * Copyright (C) 2012 Renesas Electronics Corporation
   * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>

   */
  
  #include <linux/device.h>
  #include <linux/err.h>
  #include <linux/i2c.h>
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/mfd/as3711.h>
  #include <linux/mfd/core.h>

  #include <linux/of.h>

  #include <linux/regmap.h>
  #include <linux/slab.h>
  
  enum {
  	AS3711_REGULATOR,
  	AS3711_BACKLIGHT,
  };
  
  /*
   * Ok to have it static: it is only used during probing and multiple I2C devices
   * cannot be probed simultaneously. Just make sure to avoid stale data.
   */
  static struct mfd_cell as3711_subdevs[] = {
  	[AS3711_REGULATOR] = {.name = "as3711-regulator",},
  	[AS3711_BACKLIGHT] = {.name = "as3711-backlight",},
  };
  
  static bool as3711_volatile_reg(struct device *dev, unsigned int reg)
  {
  	switch (reg) {
  	case AS3711_GPIO_SIGNAL_IN:
  	case AS3711_INTERRUPT_STATUS_1:
  	case AS3711_INTERRUPT_STATUS_2:
  	case AS3711_INTERRUPT_STATUS_3:
  	case AS3711_CHARGER_STATUS_1:
  	case AS3711_CHARGER_STATUS_2:
  	case AS3711_REG_STATUS:
  		return true;
  	}
  	return false;
  }
  
  static bool as3711_precious_reg(struct device *dev, unsigned int reg)
  {
  	switch (reg) {
  	case AS3711_INTERRUPT_STATUS_1:
  	case AS3711_INTERRUPT_STATUS_2:
  	case AS3711_INTERRUPT_STATUS_3:
  		return true;
  	}
  	return false;
  }
  
  static bool as3711_readable_reg(struct device *dev, unsigned int reg)
  {
  	switch (reg) {
  	case AS3711_SD_1_VOLTAGE:
  	case AS3711_SD_2_VOLTAGE:
  	case AS3711_SD_3_VOLTAGE:
  	case AS3711_SD_4_VOLTAGE:
  	case AS3711_LDO_1_VOLTAGE:
  	case AS3711_LDO_2_VOLTAGE:
  	case AS3711_LDO_3_VOLTAGE:
  	case AS3711_LDO_4_VOLTAGE:
  	case AS3711_LDO_5_VOLTAGE:
  	case AS3711_LDO_6_VOLTAGE:
  	case AS3711_LDO_7_VOLTAGE:
  	case AS3711_LDO_8_VOLTAGE:
  	case AS3711_SD_CONTROL:
  	case AS3711_GPIO_SIGNAL_OUT:
  	case AS3711_GPIO_SIGNAL_IN:
  	case AS3711_SD_CONTROL_1:
  	case AS3711_SD_CONTROL_2:
  	case AS3711_CURR_CONTROL:
  	case AS3711_CURR1_VALUE:
  	case AS3711_CURR2_VALUE:
  	case AS3711_CURR3_VALUE:
  	case AS3711_STEPUP_CONTROL_1:
  	case AS3711_STEPUP_CONTROL_2:
  	case AS3711_STEPUP_CONTROL_4:
  	case AS3711_STEPUP_CONTROL_5:
  	case AS3711_REG_STATUS:
  	case AS3711_INTERRUPT_STATUS_1:
  	case AS3711_INTERRUPT_STATUS_2:
  	case AS3711_INTERRUPT_STATUS_3:
  	case AS3711_CHARGER_STATUS_1:
  	case AS3711_CHARGER_STATUS_2:
  	case AS3711_ASIC_ID_1:
  	case AS3711_ASIC_ID_2:
  		return true;
  	}
  	return false;
  }
  
  static const struct regmap_config as3711_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,
  	.volatile_reg = as3711_volatile_reg,
  	.readable_reg = as3711_readable_reg,
  	.precious_reg = as3711_precious_reg,

  	.max_register = AS3711_MAX_REG,
  	.num_reg_defaults_raw = AS3711_NUM_REGS,

  	.cache_type = REGCACHE_RBTREE,
  };

  #ifdef CONFIG_OF

  static const struct of_device_id as3711_of_match[] = {

  	{.compatible = "ams,as3711",},
  	{}
  };

  #endif

  static int as3711_i2c_probe(struct i2c_client *client,
  			    const struct i2c_device_id *id)
  {
  	struct as3711 *as3711;

  	struct as3711_platform_data *pdata;

  	unsigned int id1, id2;
  	int ret;

  	if (!client->dev.of_node) {

  		pdata = dev_get_platdata(&client->dev);

  		if (!pdata)
  			dev_dbg(&client->dev, "Platform data not found
  ");
  	} else {
  		pdata = devm_kzalloc(&client->dev,
  				     sizeof(*pdata), GFP_KERNEL);

  		if (!pdata)

  			return -ENOMEM;

  	}

  
  	as3711 = devm_kzalloc(&client->dev, sizeof(struct as3711), GFP_KERNEL);

  	if (!as3711)

  		return -ENOMEM;

  
  	as3711->dev = &client->dev;
  	i2c_set_clientdata(client, as3711);
  
  	if (client->irq)
  		dev_notice(&client->dev, "IRQ not supported yet
  ");
  
  	as3711->regmap = devm_regmap_init_i2c(client, &as3711_regmap_config);
  	if (IS_ERR(as3711->regmap)) {
  		ret = PTR_ERR(as3711->regmap);

  		dev_err(&client->dev,
  			"regmap initialization failed: %d
  ", ret);

  		return ret;
  	}
  
  	ret = regmap_read(as3711->regmap, AS3711_ASIC_ID_1, &id1);
  	if (!ret)
  		ret = regmap_read(as3711->regmap, AS3711_ASIC_ID_2, &id2);
  	if (ret < 0) {
  		dev_err(&client->dev, "regmap_read() failed: %d
  ", ret);
  		return ret;
  	}
  	if (id1 != 0x8b)
  		return -ENODEV;
  	dev_info(as3711->dev, "AS3711 detected: %x:%x
  ", id1, id2);

  	/*
  	 * We can reuse as3711_subdevs[],
  	 * it will be copied in mfd_add_devices()
  	 */

  	if (pdata) {

  		as3711_subdevs[AS3711_REGULATOR].platform_data =
  			&pdata->regulator;
  		as3711_subdevs[AS3711_REGULATOR].pdata_size =
  			sizeof(pdata->regulator);
  		as3711_subdevs[AS3711_BACKLIGHT].platform_data =
  			&pdata->backlight;
  		as3711_subdevs[AS3711_BACKLIGHT].pdata_size =
  			sizeof(pdata->backlight);

  	} else {
  		as3711_subdevs[AS3711_REGULATOR].platform_data = NULL;
  		as3711_subdevs[AS3711_REGULATOR].pdata_size = 0;
  		as3711_subdevs[AS3711_BACKLIGHT].platform_data = NULL;
  		as3711_subdevs[AS3711_BACKLIGHT].pdata_size = 0;
  	}

  	ret = devm_mfd_add_devices(as3711->dev, -1, as3711_subdevs,
  				   ARRAY_SIZE(as3711_subdevs), NULL, 0, NULL);

  	if (ret < 0)
  		dev_err(&client->dev, "add mfd devices failed: %d
  ", ret);
  
  	return ret;
  }

  static const struct i2c_device_id as3711_i2c_id[] = {
  	{.name = "as3711", .driver_data = 0},
  	{}
  };

  static struct i2c_driver as3711_i2c_driver = {
  	.driver = {
  		   .name = "as3711",

  		   .of_match_table = of_match_ptr(as3711_of_match),
  	},

  	.probe = as3711_i2c_probe,

  	.id_table = as3711_i2c_id,
  };
  
  static int __init as3711_i2c_init(void)
  {
  	return i2c_add_driver(&as3711_i2c_driver);
  }
  /* Initialise early */
  subsys_initcall(as3711_i2c_init);