text: /*
   * wm831x-dcdc.c  --  DC-DC buck convertor driver for the WM831x series
   *
   * 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/i2c.h>
  #include <linux/platform_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  #include <linux/gpio.h>
  #include <linux/slab.h>
  
  #include <linux/mfd/wm831x/core.h>
  #include <linux/mfd/wm831x/regulator.h>
  #include <linux/mfd/wm831x/pdata.h>
  
  #define WM831X_BUCKV_MAX_SELECTOR 0x68
  #define WM831X_BUCKP_MAX_SELECTOR 0x66
  
  #define WM831X_DCDC_MODE_FAST    0
  #define WM831X_DCDC_MODE_NORMAL  1
  #define WM831X_DCDC_MODE_IDLE    2
  #define WM831X_DCDC_MODE_STANDBY 3
  
  #define WM831X_DCDC_MAX_NAME 9
  
  /* Register offsets in control block */
  #define WM831X_DCDC_CONTROL_1     0
  #define WM831X_DCDC_CONTROL_2     1
  #define WM831X_DCDC_ON_CONFIG     2
  #define WM831X_DCDC_SLEEP_CONTROL 3
  #define WM831X_DCDC_DVS_CONTROL   4
  
  /*
   * Shared
   */
  
  struct wm831x_dcdc {
  	char name[WM831X_DCDC_MAX_NAME];
  	char supply_name[WM831X_DCDC_MAX_NAME];
  	struct regulator_desc desc;
  	int base;
  	struct wm831x *wm831x;
  	struct regulator_dev *regulator;
  	int dvs_gpio;
  	int dvs_gpio_state;
  	int on_vsel;
  	int dvs_vsel;
  };
  
  static unsigned int wm831x_dcdc_get_mode(struct regulator_dev *rdev)
  
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	u16 reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
  	int val;
  
  	val = wm831x_reg_read(wm831x, reg);
  	if (val < 0)
  		return val;
  
  	val = (val & WM831X_DC1_ON_MODE_MASK) >> WM831X_DC1_ON_MODE_SHIFT;
  
  	switch (val) {
  	case WM831X_DCDC_MODE_FAST:
  		return REGULATOR_MODE_FAST;
  	case WM831X_DCDC_MODE_NORMAL:
  		return REGULATOR_MODE_NORMAL;
  	case WM831X_DCDC_MODE_STANDBY:
  		return REGULATOR_MODE_STANDBY;
  	case WM831X_DCDC_MODE_IDLE:
  		return REGULATOR_MODE_IDLE;
  	default:
  		BUG();
  		return -EINVAL;
  	}
  }
  
  static int wm831x_dcdc_set_mode_int(struct wm831x *wm831x, int reg,
  				    unsigned int mode)
  {
  	int val;
  
  	switch (mode) {
  	case REGULATOR_MODE_FAST:
  		val = WM831X_DCDC_MODE_FAST;
  		break;
  	case REGULATOR_MODE_NORMAL:
  		val = WM831X_DCDC_MODE_NORMAL;
  		break;
  	case REGULATOR_MODE_STANDBY:
  		val = WM831X_DCDC_MODE_STANDBY;
  		break;
  	case REGULATOR_MODE_IDLE:
  		val = WM831X_DCDC_MODE_IDLE;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return wm831x_set_bits(wm831x, reg, WM831X_DC1_ON_MODE_MASK,
  			       val << WM831X_DC1_ON_MODE_SHIFT);
  }
  
  static int wm831x_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	u16 reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
  
  	return wm831x_dcdc_set_mode_int(wm831x, reg, mode);
  }
  
  static int wm831x_dcdc_set_suspend_mode(struct regulator_dev *rdev,
  					unsigned int mode)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	u16 reg = dcdc->base + WM831X_DCDC_SLEEP_CONTROL;
  
  	return wm831x_dcdc_set_mode_int(wm831x, reg, mode);
  }
  
  static int wm831x_dcdc_get_status(struct regulator_dev *rdev)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	int ret;
  
  	/* First, check for errors */
  	ret = wm831x_reg_read(wm831x, WM831X_DCDC_UV_STATUS);
  	if (ret < 0)
  		return ret;
  
  	if (ret & (1 << rdev_get_id(rdev))) {
  		dev_dbg(wm831x->dev, "DCDC%d under voltage\n",
  			rdev_get_id(rdev) + 1);
  		return REGULATOR_STATUS_ERROR;
  	}
  
  	/* DCDC1 and DCDC2 can additionally detect high voltage/current */
  	if (rdev_get_id(rdev) < 2) {
  		if (ret & (WM831X_DC1_OV_STS << rdev_get_id(rdev))) {
  			dev_dbg(wm831x->dev, "DCDC%d over voltage\n",
  				rdev_get_id(rdev) + 1);
  			return REGULATOR_STATUS_ERROR;
  		}
  
  		if (ret & (WM831X_DC1_HC_STS << rdev_get_id(rdev))) {
  			dev_dbg(wm831x->dev, "DCDC%d over current\n",
  				rdev_get_id(rdev) + 1);
  			return REGULATOR_STATUS_ERROR;
  		}
  	}
  
  	/* Is the regulator on? */
  	ret = wm831x_reg_read(wm831x, WM831X_DCDC_STATUS);
  	if (ret < 0)
  		return ret;
  	if (!(ret & (1 << rdev_get_id(rdev))))
  		return REGULATOR_STATUS_OFF;
  
  	/* TODO: When we handle hardware control modes so we can report the
  	 * current mode. */
  	return REGULATOR_STATUS_ON;
  }
  
  static irqreturn_t wm831x_dcdc_uv_irq(int irq, void *data)
  {
  	struct wm831x_dcdc *dcdc = data;
  
  	regulator_lock(dcdc->regulator);
  	regulator_notifier_call_chain(dcdc->regulator,
  				      REGULATOR_EVENT_UNDER_VOLTAGE,
  				      NULL);
  	regulator_unlock(dcdc->regulator);
  
  	return IRQ_HANDLED;
  }
  
  static irqreturn_t wm831x_dcdc_oc_irq(int irq, void *data)
  {
  	struct wm831x_dcdc *dcdc = data;
  
  	regulator_lock(dcdc->regulator);
  	regulator_notifier_call_chain(dcdc->regulator,
  				      REGULATOR_EVENT_OVER_CURRENT,
  				      NULL);
  	regulator_unlock(dcdc->regulator);
  
  	return IRQ_HANDLED;
  }
  
  /*
   * BUCKV specifics
   */
  
  static const struct regulator_linear_range wm831x_buckv_ranges[] = {
  	REGULATOR_LINEAR_RANGE(600000, 0, 0x7, 0),
  	REGULATOR_LINEAR_RANGE(600000, 0x8, 0x68, 12500),
  };
  
  static int wm831x_buckv_set_dvs(struct regulator_dev *rdev, int state)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  
  	if (state == dcdc->dvs_gpio_state)
  		return 0;
  
  	dcdc->dvs_gpio_state = state;
  	gpio_set_value(dcdc->dvs_gpio, state);
  
  	/* Should wait for DVS state change to be asserted if we have
  	 * a GPIO for it, for now assume the device is configured
  	 * for the fastest possible transition.
  	 */
  
  	return 0;
  }
  
  static int wm831x_buckv_set_voltage_sel(struct regulator_dev *rdev,
  					unsigned vsel)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	int on_reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
  	int dvs_reg = dcdc->base + WM831X_DCDC_DVS_CONTROL;
  	int ret;
  
  	/* If this value is already set then do a GPIO update if we can */
  	if (dcdc->dvs_gpio && dcdc->on_vsel == vsel)
  		return wm831x_buckv_set_dvs(rdev, 0);
  
  	if (dcdc->dvs_gpio && dcdc->dvs_vsel == vsel)
  		return wm831x_buckv_set_dvs(rdev, 1);
  
  	/* Always set the ON status to the minimum voltage */
  	ret = wm831x_set_bits(wm831x, on_reg, WM831X_DC1_ON_VSEL_MASK, vsel);
  	if (ret < 0)
  		return ret;
  	dcdc->on_vsel = vsel;
  
  	if (!dcdc->dvs_gpio)
  		return ret;
  
  	/* Kick the voltage transition now */
  	ret = wm831x_buckv_set_dvs(rdev, 0);
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * If this VSEL is higher than the last one we've seen then
  	 * remember it as the DVS VSEL.  This is optimised for CPUfreq
  	 * usage where we want to get to the highest voltage very
  	 * quickly.
  	 */
  	if (vsel > dcdc->dvs_vsel) {
  		ret = wm831x_set_bits(wm831x, dvs_reg,
  				      WM831X_DC1_DVS_VSEL_MASK,
  				      vsel);
  		if (ret == 0)
  			dcdc->dvs_vsel = vsel;
  		else
  			dev_warn(wm831x->dev,
  				 "Failed to set DCDC DVS VSEL: %d\n", ret);
  	}
  
  	return 0;
  }
  
  static int wm831x_buckv_set_suspend_voltage(struct regulator_dev *rdev,
  					    int uV)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	u16 reg = dcdc->base + WM831X_DCDC_SLEEP_CONTROL;
  	int vsel;
  
  	vsel = regulator_map_voltage_linear_range(rdev, uV, uV);
  	if (vsel < 0)
  		return vsel;
  
  	return wm831x_set_bits(wm831x, reg, WM831X_DC1_SLP_VSEL_MASK, vsel);
  }
  
  static int wm831x_buckv_get_voltage_sel(struct regulator_dev *rdev)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  
  	if (dcdc->dvs_gpio && dcdc->dvs_gpio_state)
  		return dcdc->dvs_vsel;
  	else
  		return dcdc->on_vsel;
  }
  
  /* Current limit options */
  static const unsigned int wm831x_dcdc_ilim[] = {
  	125000, 250000, 375000, 500000, 625000, 750000, 875000, 1000000
  };
  
  static const struct regulator_ops wm831x_buckv_ops = {
  	.set_voltage_sel = wm831x_buckv_set_voltage_sel,
  	.get_voltage_sel = wm831x_buckv_get_voltage_sel,
  	.list_voltage = regulator_list_voltage_linear_range,
  	.map_voltage = regulator_map_voltage_linear_range,
  	.set_suspend_voltage = wm831x_buckv_set_suspend_voltage,
  	.set_current_limit = regulator_set_current_limit_regmap,
  	.get_current_limit = regulator_get_current_limit_regmap,
  
  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  	.get_status = wm831x_dcdc_get_status,
  	.get_mode = wm831x_dcdc_get_mode,
  	.set_mode = wm831x_dcdc_set_mode,
  	.set_suspend_mode = wm831x_dcdc_set_suspend_mode,
  };
  
  /*
   * Set up DVS control.  We just log errors since we can still run
   * (with reduced performance) if we fail.
   */
  static void wm831x_buckv_dvs_init(struct platform_device *pdev,
  				  struct wm831x_dcdc *dcdc,
  				  struct wm831x_buckv_pdata *pdata)
  {
  	struct wm831x *wm831x = dcdc->wm831x;
  	int ret;
  	u16 ctrl;
  
  	if (!pdata || !pdata->dvs_gpio)
  		return;
  
  	/* gpiolib won't let us read the GPIO status so pick the higher
  	 * of the two existing voltages so we take it as platform data.
  	 */
  	dcdc->dvs_gpio_state = pdata->dvs_init_state;
  
  	ret = devm_gpio_request_one(&pdev->dev, pdata->dvs_gpio,
  				    dcdc->dvs_gpio_state ? GPIOF_INIT_HIGH : 0,
  				    "DCDC DVS");
  	if (ret < 0) {
  		dev_err(wm831x->dev, "Failed to get %s DVS GPIO: %d\n",
  			dcdc->name, ret);
  		return;
  	}
  
  	dcdc->dvs_gpio = pdata->dvs_gpio;
  
  	switch (pdata->dvs_control_src) {
  	case 1:
  		ctrl = 2 << WM831X_DC1_DVS_SRC_SHIFT;
  		break;
  	case 2:
  		ctrl = 3 << WM831X_DC1_DVS_SRC_SHIFT;
  		break;
  	default:
  		dev_err(wm831x->dev, "Invalid DVS control source %d for %s\n",
  			pdata->dvs_control_src, dcdc->name);
  		return;
  	}
  
  	/* If DVS_VSEL is set to the minimum value then raise it to ON_VSEL
  	 * to make bootstrapping a bit smoother.
  	 */
  	if (!dcdc->dvs_vsel) {
  		ret = wm831x_set_bits(wm831x,
  				      dcdc->base + WM831X_DCDC_DVS_CONTROL,
  				      WM831X_DC1_DVS_VSEL_MASK, dcdc->on_vsel);
  		if (ret == 0)
  			dcdc->dvs_vsel = dcdc->on_vsel;
  		else
  			dev_warn(wm831x->dev, "Failed to set DVS_VSEL: %d\n",
  				 ret);
  	}
  
  	ret = wm831x_set_bits(wm831x, dcdc->base + WM831X_DCDC_DVS_CONTROL,
  			      WM831X_DC1_DVS_SRC_MASK, ctrl);
  	if (ret < 0) {
  		dev_err(wm831x->dev, "Failed to set %s DVS source: %d\n",
  			dcdc->name, ret);
  	}
  }
  
  static int wm831x_buckv_probe(struct platform_device *pdev)
  {
  	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
  	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
  	struct regulator_config config = { };
  	int id;
  	struct wm831x_dcdc *dcdc;
  	struct resource *res;
  	int ret, irq;
  
  	if (pdata && pdata->wm831x_num)
  		id = (pdata->wm831x_num * 10) + 1;
  	else
  		id = 0;
  	id = pdev->id - id;
  
  	dev_dbg(&pdev->dev, "Probing DCDC%d\n", id + 1);
  
  	dcdc = devm_kzalloc(&pdev->dev,  sizeof(struct wm831x_dcdc),
  			    GFP_KERNEL);
  	if (!dcdc)
  		return -ENOMEM;
  
  	dcdc->wm831x = wm831x;
  
  	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
  	if (res == NULL) {
  		dev_err(&pdev->dev, "No REG resource\n");
  		ret = -EINVAL;
  		goto err;
  	}
  	dcdc->base = res->start;
  
  	snprintf(dcdc->name, sizeof(dcdc->name), "DCDC%d", id + 1);
  	dcdc->desc.name = dcdc->name;
  
  	snprintf(dcdc->supply_name, sizeof(dcdc->supply_name),
  		 "DC%dVDD", id + 1);
  	dcdc->desc.supply_name = dcdc->supply_name;
  
  	dcdc->desc.id = id;
  	dcdc->desc.type = REGULATOR_VOLTAGE;
  	dcdc->desc.n_voltages = WM831X_BUCKV_MAX_SELECTOR + 1;
  	dcdc->desc.linear_ranges = wm831x_buckv_ranges;
  	dcdc->desc.n_linear_ranges = ARRAY_SIZE(wm831x_buckv_ranges);
  	dcdc->desc.ops = &wm831x_buckv_ops;
  	dcdc->desc.owner = THIS_MODULE;
  	dcdc->desc.enable_reg = WM831X_DCDC_ENABLE;
  	dcdc->desc.enable_mask = 1 << id;
  	dcdc->desc.csel_reg = dcdc->base + WM831X_DCDC_CONTROL_2;
  	dcdc->desc.csel_mask = WM831X_DC1_HC_THR_MASK;
  	dcdc->desc.n_current_limits = ARRAY_SIZE(wm831x_dcdc_ilim);
  	dcdc->desc.curr_table = wm831x_dcdc_ilim;
  
  	ret = wm831x_reg_read(wm831x, dcdc->base + WM831X_DCDC_ON_CONFIG);
  	if (ret < 0) {
  		dev_err(wm831x->dev, "Failed to read ON VSEL: %d\n", ret);
  		goto err;
  	}
  	dcdc->on_vsel = ret & WM831X_DC1_ON_VSEL_MASK;
  
  	ret = wm831x_reg_read(wm831x, dcdc->base + WM831X_DCDC_DVS_CONTROL);
  	if (ret < 0) {
  		dev_err(wm831x->dev, "Failed to read DVS VSEL: %d\n", ret);
  		goto err;
  	}
  	dcdc->dvs_vsel = ret & WM831X_DC1_DVS_VSEL_MASK;
  
  	if (pdata && pdata->dcdc[id])
  		wm831x_buckv_dvs_init(pdev, dcdc,
  				      pdata->dcdc[id]->driver_data);
  
  	config.dev = pdev->dev.parent;
  	if (pdata)
  		config.init_data = pdata->dcdc[id];
  	config.driver_data = dcdc;
  	config.regmap = wm831x->regmap;
  
  	dcdc->regulator = devm_regulator_register(&pdev->dev, &dcdc->desc,
  						  &config);
  	if (IS_ERR(dcdc->regulator)) {
  		ret = PTR_ERR(dcdc->regulator);
  		dev_err(wm831x->dev, "Failed to register DCDC%d: %d\n",
  			id + 1, ret);
  		goto err;
  	}
  
  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "UV"));
  	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
  					wm831x_dcdc_uv_irq,
  					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  					dcdc->name, dcdc);
  	if (ret != 0) {
  		dev_err(&pdev->dev, "Failed to request UV IRQ %d: %d\n",
  			irq, ret);
  		goto err;
  	}
  
  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "HC"));
  	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
  					wm831x_dcdc_oc_irq,
  					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  					dcdc->name, dcdc);
  	if (ret != 0) {
  		dev_err(&pdev->dev, "Failed to request HC IRQ %d: %d\n",
  			irq, ret);
  		goto err;
  	}
  
  	platform_set_drvdata(pdev, dcdc);
  
  	return 0;
  
  err:
  	return ret;
  }
  
  static struct platform_driver wm831x_buckv_driver = {
  	.probe = wm831x_buckv_probe,
  	.driver		= {
  		.name	= "wm831x-buckv",
  	},
  };
  
  /*
   * BUCKP specifics
   */
  
  static int wm831x_buckp_set_suspend_voltage(struct regulator_dev *rdev, int uV)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	u16 reg = dcdc->base + WM831X_DCDC_SLEEP_CONTROL;
  	int sel;
  
  	sel = regulator_map_voltage_linear(rdev, uV, uV);
  	if (sel < 0)
  		return sel;
  
  	return wm831x_set_bits(wm831x, reg, WM831X_DC3_ON_VSEL_MASK, sel);
  }
  
  static const struct regulator_ops wm831x_buckp_ops = {
  	.set_voltage_sel = regulator_set_voltage_sel_regmap,
  	.get_voltage_sel = regulator_get_voltage_sel_regmap,
  	.list_voltage = regulator_list_voltage_linear,
  	.map_voltage = regulator_map_voltage_linear,
  	.set_suspend_voltage = wm831x_buckp_set_suspend_voltage,
  
  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  	.get_status = wm831x_dcdc_get_status,
  	.get_mode = wm831x_dcdc_get_mode,
  	.set_mode = wm831x_dcdc_set_mode,
  	.set_suspend_mode = wm831x_dcdc_set_suspend_mode,
  };
  
  static int wm831x_buckp_probe(struct platform_device *pdev)
  {
  	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
  	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
  	struct regulator_config config = { };
  	int id;
  	struct wm831x_dcdc *dcdc;
  	struct resource *res;
  	int ret, irq;
  
  	if (pdata && pdata->wm831x_num)
  		id = (pdata->wm831x_num * 10) + 1;
  	else
  		id = 0;
  	id = pdev->id - id;
  
  	dev_dbg(&pdev->dev, "Probing DCDC%d\n", id + 1);
  
  	dcdc = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_dcdc),
  			    GFP_KERNEL);
  	if (!dcdc)
  		return -ENOMEM;
  
  	dcdc->wm831x = wm831x;
  
  	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
  	if (res == NULL) {
  		dev_err(&pdev->dev, "No REG resource\n");
  		ret = -EINVAL;
  		goto err;
  	}
  	dcdc->base = res->start;
  
  	snprintf(dcdc->name, sizeof(dcdc->name), "DCDC%d", id + 1);
  	dcdc->desc.name = dcdc->name;
  
  	snprintf(dcdc->supply_name, sizeof(dcdc->supply_name),
  		 "DC%dVDD", id + 1);
  	dcdc->desc.supply_name = dcdc->supply_name;
  
  	dcdc->desc.id = id;
  	dcdc->desc.type = REGULATOR_VOLTAGE;
  	dcdc->desc.n_voltages = WM831X_BUCKP_MAX_SELECTOR + 1;
  	dcdc->desc.ops = &wm831x_buckp_ops;
  	dcdc->desc.owner = THIS_MODULE;
  	dcdc->desc.vsel_reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
  	dcdc->desc.vsel_mask = WM831X_DC3_ON_VSEL_MASK;
  	dcdc->desc.enable_reg = WM831X_DCDC_ENABLE;
  	dcdc->desc.enable_mask = 1 << id;
  	dcdc->desc.min_uV = 850000;
  	dcdc->desc.uV_step = 25000;
  
  	config.dev = pdev->dev.parent;
  	if (pdata)
  		config.init_data = pdata->dcdc[id];
  	config.driver_data = dcdc;
  	config.regmap = wm831x->regmap;
  
  	dcdc->regulator = devm_regulator_register(&pdev->dev, &dcdc->desc,
  						  &config);
  	if (IS_ERR(dcdc->regulator)) {
  		ret = PTR_ERR(dcdc->regulator);
  		dev_err(wm831x->dev, "Failed to register DCDC%d: %d\n",
  			id + 1, ret);
  		goto err;
  	}
  
  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "UV"));
  	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
  					wm831x_dcdc_uv_irq,
  					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  					dcdc->name, dcdc);
  	if (ret != 0) {
  		dev_err(&pdev->dev, "Failed to request UV IRQ %d: %d\n",
  			irq, ret);
  		goto err;
  	}
  
  	platform_set_drvdata(pdev, dcdc);
  
  	return 0;
  
  err:
  	return ret;
  }
  
  static struct platform_driver wm831x_buckp_driver = {
  	.probe = wm831x_buckp_probe,
  	.driver		= {
  		.name	= "wm831x-buckp",
  	},
  };
  
  /*
   * DCDC boost convertors
   */
  
  static int wm831x_boostp_get_status(struct regulator_dev *rdev)
  {
  	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
  	struct wm831x *wm831x = dcdc->wm831x;
  	int ret;
  
  	/* First, check for errors */
  	ret = wm831x_reg_read(wm831x, WM831X_DCDC_UV_STATUS);
  	if (ret < 0)
  		return ret;
  
  	if (ret & (1 << rdev_get_id(rdev))) {
  		dev_dbg(wm831x->dev, "DCDC%d under voltage\n",
  			rdev_get_id(rdev) + 1);
  		return REGULATOR_STATUS_ERROR;
  	}
  
  	/* Is the regulator on? */
  	ret = wm831x_reg_read(wm831x, WM831X_DCDC_STATUS);
  	if (ret < 0)
  		return ret;
  	if (ret & (1 << rdev_get_id(rdev)))
  		return REGULATOR_STATUS_ON;
  	else
  		return REGULATOR_STATUS_OFF;
  }
  
  static const struct regulator_ops wm831x_boostp_ops = {
  	.get_status = wm831x_boostp_get_status,
  
  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  };
  
  static int wm831x_boostp_probe(struct platform_device *pdev)
  {
  	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
  	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
  	struct regulator_config config = { };
  	int id = pdev->id % ARRAY_SIZE(pdata->dcdc);
  	struct wm831x_dcdc *dcdc;
  	struct resource *res;
  	int ret, irq;
  
  	dev_dbg(&pdev->dev, "Probing DCDC%d\n", id + 1);
  
  	if (pdata == NULL || pdata->dcdc[id] == NULL)
  		return -ENODEV;
  
  	dcdc = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_dcdc), GFP_KERNEL);
  	if (!dcdc)
  		return -ENOMEM;
  
  	dcdc->wm831x = wm831x;
  
  	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
  	if (res == NULL) {
  		dev_err(&pdev->dev, "No REG resource\n");
  		return -EINVAL;
  	}
  	dcdc->base = res->start;
  
  	snprintf(dcdc->name, sizeof(dcdc->name), "DCDC%d", id + 1);
  	dcdc->desc.name = dcdc->name;
  	dcdc->desc.id = id;
  	dcdc->desc.type = REGULATOR_VOLTAGE;
  	dcdc->desc.ops = &wm831x_boostp_ops;
  	dcdc->desc.owner = THIS_MODULE;
  	dcdc->desc.enable_reg = WM831X_DCDC_ENABLE;
  	dcdc->desc.enable_mask = 1 << id;
  
  	config.dev = pdev->dev.parent;
  	if (pdata)
  		config.init_data = pdata->dcdc[id];
  	config.driver_data = dcdc;
  	config.regmap = wm831x->regmap;
  
  	dcdc->regulator = devm_regulator_register(&pdev->dev, &dcdc->desc,
  						  &config);
  	if (IS_ERR(dcdc->regulator)) {
  		ret = PTR_ERR(dcdc->regulator);
  		dev_err(wm831x->dev, "Failed to register DCDC%d: %d\n",
  			id + 1, ret);
  		return ret;
  	}
  
  	irq = wm831x_irq(wm831x, platform_get_irq_byname(pdev, "UV"));
  	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
  					wm831x_dcdc_uv_irq,
  					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  					dcdc->name,
  					dcdc);
  	if (ret != 0) {
  		dev_err(&pdev->dev, "Failed to request UV IRQ %d: %d\n",
  			irq, ret);
  		return ret;
  	}
  
  	platform_set_drvdata(pdev, dcdc);
  
  	return 0;
  }
  
  static struct platform_driver wm831x_boostp_driver = {
  	.probe = wm831x_boostp_probe,
  	.driver		= {
  		.name	= "wm831x-boostp",
  	},
  };
  
  /*
   * External Power Enable
   *
   * These aren't actually DCDCs but look like them in hardware so share
   * code.
   */
  
  #define WM831X_EPE_BASE 6
  
  static const struct regulator_ops wm831x_epe_ops = {
  	.is_enabled = regulator_is_enabled_regmap,
  	.enable = regulator_enable_regmap,
  	.disable = regulator_disable_regmap,
  	.get_status = wm831x_dcdc_get_status,
  };
  
  static int wm831x_epe_probe(struct platform_device *pdev)
  {
  	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
  	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
  	struct regulator_config config = { };
  	int id = pdev->id % ARRAY_SIZE(pdata->epe);
  	struct wm831x_dcdc *dcdc;
  	int ret;
  
  	dev_dbg(&pdev->dev, "Probing EPE%d\n", id + 1);
  
  	dcdc = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_dcdc), GFP_KERNEL);
  	if (!dcdc)
  		return -ENOMEM;
  
  	dcdc->wm831x = wm831x;
  
  	/* For current parts this is correct; probably need to revisit
  	 * in future.
  	 */
  	snprintf(dcdc->name, sizeof(dcdc->name), "EPE%d", id + 1);
  	dcdc->desc.name = dcdc->name;
  	dcdc->desc.id = id + WM831X_EPE_BASE; /* Offset in DCDC registers */
  	dcdc->desc.ops = &wm831x_epe_ops;
  	dcdc->desc.type = REGULATOR_VOLTAGE;
  	dcdc->desc.owner = THIS_MODULE;
  	dcdc->desc.enable_reg = WM831X_DCDC_ENABLE;
  	dcdc->desc.enable_mask = 1 << dcdc->desc.id;
  
  	config.dev = pdev->dev.parent;
  	if (pdata)
  		config.init_data = pdata->epe[id];
  	config.driver_data = dcdc;
  	config.regmap = wm831x->regmap;
  
  	dcdc->regulator = devm_regulator_register(&pdev->dev, &dcdc->desc,
  						  &config);
  	if (IS_ERR(dcdc->regulator)) {
  		ret = PTR_ERR(dcdc->regulator);
  		dev_err(wm831x->dev, "Failed to register EPE%d: %d\n",
  			id + 1, ret);
  		goto err;
  	}
  
  	platform_set_drvdata(pdev, dcdc);
  
  	return 0;
  
  err:
  	return ret;
  }
  
  static struct platform_driver wm831x_epe_driver = {
  	.probe = wm831x_epe_probe,
  	.driver		= {
  		.name	= "wm831x-epe",
  	},
  };
  
  static struct platform_driver * const drivers[] = {
  	&wm831x_buckv_driver,
  	&wm831x_buckp_driver,
  	&wm831x_boostp_driver,
  	&wm831x_epe_driver,
  };
  
  static int __init wm831x_dcdc_init(void)
  {
  	return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
  }
  subsys_initcall(wm831x_dcdc_init);
  
  static void __exit wm831x_dcdc_exit(void)
  {
  	platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
  }
  module_exit(wm831x_dcdc_exit);
  
  /* Module information */
  MODULE_AUTHOR("Mark Brown");
  MODULE_DESCRIPTION("WM831x DC-DC convertor driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:wm831x-buckv");
  MODULE_ALIAS("platform:wm831x-buckp");
  MODULE_ALIAS("platform:wm831x-boostp");
  MODULE_ALIAS("platform:wm831x-epe");
  