text: /*
   * wm8994-regulator.c  --  Regulator driver for the WM8994
   *
   * Copyright 2009 Wolfson Microelectronics PLC.
   *
   * Author: Mark Brown <broonie@opensource.wolfsonmicro.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/module.h>
  #include <linux/moduleparam.h>
  #include <linux/init.h>
  #include <linux/bitops.h>
  #include <linux/err.h>
  #include <linux/platform_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/gpio.h>
  #include <linux/slab.h>
  
  #include <linux/mfd/wm8994/core.h>
  #include <linux/mfd/wm8994/registers.h>
  #include <linux/mfd/wm8994/pdata.h>
  
  struct wm8994_ldo {
  	int enable;
  	bool is_enabled;
  	struct regulator_dev *regulator;
  	struct wm8994 *wm8994;
  };
  
  #define WM8994_LDO1_MAX_SELECTOR 0x7
  #define WM8994_LDO2_MAX_SELECTOR 0x3
  
  static int wm8994_ldo_enable(struct regulator_dev *rdev)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  
  	/* If we have no soft control assume that the LDO is always enabled. */
  	if (!ldo->enable)
  		return 0;
  
  	gpio_set_value(ldo->enable, 1);
  	ldo->is_enabled = true;
  
  	return 0;
  }
  
  static int wm8994_ldo_disable(struct regulator_dev *rdev)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  
  	/* If we have no soft control assume that the LDO is always enabled. */
  	if (!ldo->enable)
  		return -EINVAL;
  
  	gpio_set_value(ldo->enable, 0);
  	ldo->is_enabled = false;
  
  	return 0;
  }
  
  static int wm8994_ldo_is_enabled(struct regulator_dev *rdev)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  
  	return ldo->is_enabled;
  }
  
  static int wm8994_ldo_enable_time(struct regulator_dev *rdev)
  {
  	/* 3ms is fairly conservative but this shouldn't be too performance
  	 * critical; can be tweaked per-system if required. */
  	return 3000;
  }
  
  static int wm8994_ldo1_list_voltage(struct regulator_dev *rdev,
  				    unsigned int selector)
  {
  	if (selector > WM8994_LDO1_MAX_SELECTOR)
  		return -EINVAL;
  
  	return (selector * 100000) + 2400000;
  }
  
  static int wm8994_ldo1_get_voltage_sel(struct regulator_dev *rdev)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  	int val;
  
  	val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_1);
  	if (val < 0)
  		return val;
  
  	return (val & WM8994_LDO1_VSEL_MASK) >> WM8994_LDO1_VSEL_SHIFT;
  }
  
  static int wm8994_ldo1_set_voltage(struct regulator_dev *rdev,
  				   int min_uV, int max_uV, unsigned *s)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  	int selector, v;
  
  	selector = (min_uV - 2400000) / 100000;
  	v = wm8994_ldo1_list_voltage(rdev, selector);
  	if (v < 0 || v > max_uV)
  		return -EINVAL;
  
  	*s = selector;
  	selector <<= WM8994_LDO1_VSEL_SHIFT;
  
  	return wm8994_set_bits(ldo->wm8994, WM8994_LDO_1,
  			       WM8994_LDO1_VSEL_MASK, selector);
  }
  
  static struct regulator_ops wm8994_ldo1_ops = {
  	.enable = wm8994_ldo_enable,
  	.disable = wm8994_ldo_disable,
  	.is_enabled = wm8994_ldo_is_enabled,
  	.enable_time = wm8994_ldo_enable_time,
  
  	.list_voltage = wm8994_ldo1_list_voltage,
  	.get_voltage_sel = wm8994_ldo1_get_voltage_sel,
  	.set_voltage = wm8994_ldo1_set_voltage,
  };
  
  static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
  				    unsigned int selector)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  
  	if (selector > WM8994_LDO2_MAX_SELECTOR)
  		return -EINVAL;
  
  	switch (ldo->wm8994->type) {
  	case WM8994:
  		return (selector * 100000) + 900000;
  	case WM8958:
  		return (selector * 100000) + 1000000;
  	default:
  		return -EINVAL;
  	}
  }
  
  static int wm8994_ldo2_get_voltage_sel(struct regulator_dev *rdev)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  	int val;
  
  	val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_2);
  	if (val < 0)
  		return val;
  
  	return (val & WM8994_LDO2_VSEL_MASK) >> WM8994_LDO2_VSEL_SHIFT;
  }
  
  static int wm8994_ldo2_set_voltage(struct regulator_dev *rdev,
  				   int min_uV, int max_uV, unsigned *s)
  {
  	struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  	int selector, v;
  
  	switch (ldo->wm8994->type) {
  	case WM8994:
  		selector = (min_uV - 900000) / 100000;
  		break;
  	case WM8958:
  		selector = (min_uV - 1000000) / 100000;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	v = wm8994_ldo2_list_voltage(rdev, selector);
  	if (v < 0 || v > max_uV)
  		return -EINVAL;
  
  	*s = selector;
  	selector <<= WM8994_LDO2_VSEL_SHIFT;
  
  	return wm8994_set_bits(ldo->wm8994, WM8994_LDO_2,
  			       WM8994_LDO2_VSEL_MASK, selector);
  }
  
  static struct regulator_ops wm8994_ldo2_ops = {
  	.enable = wm8994_ldo_enable,
  	.disable = wm8994_ldo_disable,
  	.is_enabled = wm8994_ldo_is_enabled,
  	.enable_time = wm8994_ldo_enable_time,
  
  	.list_voltage = wm8994_ldo2_list_voltage,
  	.get_voltage_sel = wm8994_ldo2_get_voltage_sel,
  	.set_voltage = wm8994_ldo2_set_voltage,
  };
  
  static struct regulator_desc wm8994_ldo_desc[] = {
  	{
  		.name = "LDO1",
  		.id = 1,
  		.type = REGULATOR_VOLTAGE,
  		.n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
  		.ops = &wm8994_ldo1_ops,
  		.owner = THIS_MODULE,
  	},
  	{
  		.name = "LDO2",
  		.id = 2,
  		.type = REGULATOR_VOLTAGE,
  		.n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
  		.ops = &wm8994_ldo2_ops,
  		.owner = THIS_MODULE,
  	},
  };
  
  static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
  {
  	struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
  	struct wm8994_pdata *pdata = wm8994->dev->platform_data;
  	int id = pdev->id % ARRAY_SIZE(pdata->ldo);
  	struct wm8994_ldo *ldo;
  	int ret;
  
  	dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
  
  	if (!pdata)
  		return -ENODEV;
  
  	ldo = kzalloc(sizeof(struct wm8994_ldo), GFP_KERNEL);
  	if (ldo == NULL) {
  		dev_err(&pdev->dev, "Unable to allocate private data\n");
  		return -ENOMEM;
  	}
  
  	ldo->wm8994 = wm8994;
  
  	if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
  		ldo->enable = pdata->ldo[id].enable;
  
  		ret = gpio_request(ldo->enable, "WM8994 LDO enable");
  		if (ret < 0) {
  			dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
  				ret);
  			goto err;
  		}
  
  		ret = gpio_direction_output(ldo->enable, ldo->is_enabled);
  		if (ret < 0) {
  			dev_err(&pdev->dev, "Failed to set GPIO up: %d\n",
  				ret);
  			goto err_gpio;
  		}
  	} else
  		ldo->is_enabled = true;
  
  	ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &pdev->dev,
  					     pdata->ldo[id].init_data, ldo);
  	if (IS_ERR(ldo->regulator)) {
  		ret = PTR_ERR(ldo->regulator);
  		dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
  			id + 1, ret);
  		goto err_gpio;
  	}
  
  	platform_set_drvdata(pdev, ldo);
  
  	return 0;
  
  err_gpio:
  	if (gpio_is_valid(ldo->enable))
  		gpio_free(ldo->enable);
  err:
  	kfree(ldo);
  	return ret;
  }
  
  static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
  {
  	struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
  
  	platform_set_drvdata(pdev, NULL);
  
  	regulator_unregister(ldo->regulator);
  	if (gpio_is_valid(ldo->enable))
  		gpio_free(ldo->enable);
  	kfree(ldo);
  
  	return 0;
  }
  
  static struct platform_driver wm8994_ldo_driver = {
  	.probe = wm8994_ldo_probe,
  	.remove = __devexit_p(wm8994_ldo_remove),
  	.driver		= {
  		.name	= "wm8994-ldo",
  		.owner	= THIS_MODULE,
  	},
  };
  
  static int __init wm8994_ldo_init(void)
  {
  	int ret;
  
  	ret = platform_driver_register(&wm8994_ldo_driver);
  	if (ret != 0)
  		pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
  
  	return ret;
  }
  subsys_initcall(wm8994_ldo_init);
  
  static void __exit wm8994_ldo_exit(void)
  {
  	platform_driver_unregister(&wm8994_ldo_driver);
  }
  module_exit(wm8994_ldo_exit);
  
  /* Module information */
  MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
  MODULE_DESCRIPTION("WM8994 LDO driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm8994-ldo");
  