regulator: Add WM831x DC-DC buck convertor support

The WM831x series of devices all have 3 DC-DC buck convertors. This
driver implements software control for these regulators via the
regulator API.  Use with split hardware/software control of individual
regulators is not supported, though regulators not controlled by
software may be controlled via the hardware control interfaces.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 643 insertions, 0 deletions

diff --git a/drivers/regulator/wm831x-dcdc.c b/drivers/regulator/wm831x-dcdc.c
new file mode 100644
index 00000000000..fa5126e38ac
--- /dev/null
+++ b/drivers/regulator/wm831x-dcdc.c
@@ -0,0 +1,643 @@
+/*
+ * 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/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 6
+
+/* 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
+
+/*
+ * Shared
+ */
+
+struct wm831x_dcdc {
+	char name[WM831X_DCDC_MAX_NAME];
+	struct regulator_desc desc;
+	int base;
+	struct wm831x *wm831x;
+	struct regulator_dev *regulator;
+};
+
+static int wm831x_dcdc_is_enabled(struct regulator_dev *rdev)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+	int mask = 1 << rdev_get_id(rdev);
+	int reg;
+
+	reg = wm831x_reg_read(wm831x, WM831X_DCDC_ENABLE);
+	if (reg < 0)
+		return reg;
+
+	if (reg & mask)
+		return 1;
+	else
+		return 0;
+}
+
+static int wm831x_dcdc_enable(struct regulator_dev *rdev)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+	int mask = 1 << rdev_get_id(rdev);
+
+	return wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, mask, mask);
+}
+
+static int wm831x_dcdc_disable(struct regulator_dev *rdev)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+	int mask = 1 << rdev_get_id(rdev);
+
+	return wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, mask, 0);
+}
+
+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();
+	}
+}
+
+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_notifier_call_chain(dcdc->regulator,
+				      REGULATOR_EVENT_UNDER_VOLTAGE,
+				      NULL);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t wm831x_dcdc_oc_irq(int irq, void *data)
+{
+	struct wm831x_dcdc *dcdc = data;
+
+	regulator_notifier_call_chain(dcdc->regulator,
+				      REGULATOR_EVENT_OVER_CURRENT,
+				      NULL);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * BUCKV specifics
+ */
+
+static int wm831x_buckv_list_voltage(struct regulator_dev *rdev,
+				      unsigned selector)
+{
+	if (selector <= 0x8)
+		return 600000;
+	if (selector <= WM831X_BUCKV_MAX_SELECTOR)
+		return 600000 + ((selector - 0x8) * 12500);
+	return -EINVAL;
+}
+
+static int wm831x_buckv_set_voltage_int(struct regulator_dev *rdev, int reg,
+					 int min_uV, int max_uV)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+	u16 vsel;
+
+	if (min_uV < 600000)
+		vsel = 0;
+	else if (min_uV <= 1800000)
+		vsel = ((min_uV - 600000) / 12500) + 8;
+	else
+		return -EINVAL;
+
+	if (wm831x_buckv_list_voltage(rdev, vsel) > max_uV)
+		return -EINVAL;
+
+	return wm831x_set_bits(wm831x, reg, WM831X_DC1_ON_VSEL_MASK, vsel);
+}
+
+static int wm831x_buckv_set_voltage(struct regulator_dev *rdev,
+				     int min_uV, int max_uV)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	u16 reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
+
+	return wm831x_buckv_set_voltage_int(rdev, reg, min_uV, max_uV);
+}
+
+static int wm831x_buckv_set_suspend_voltage(struct regulator_dev *rdev,
+					     int uV)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	u16 reg = dcdc->base + WM831X_DCDC_SLEEP_CONTROL;
+
+	return wm831x_buckv_set_voltage_int(rdev, reg, uV, uV);
+}
+
+static int wm831x_buckv_get_voltage(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;
+
+	return wm831x_buckv_list_voltage(rdev, val & WM831X_DC1_ON_VSEL_MASK);
+}
+
+/* Current limit options */
+static u16 wm831x_dcdc_ilim[] = {
+	125, 250, 375, 500, 625, 750, 875, 1000
+};
+
+static int wm831x_buckv_set_current_limit(struct regulator_dev *rdev,
+					   int min_uA, int max_uA)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+	u16 reg = dcdc->base + WM831X_DCDC_CONTROL_2;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(wm831x_dcdc_ilim); i++) {
+		if (max_uA <= wm831x_dcdc_ilim[i])
+			break;
+	}
+	if (i == ARRAY_SIZE(wm831x_dcdc_ilim))
+		return -EINVAL;
+
+	return wm831x_set_bits(wm831x, reg, WM831X_DC1_HC_THR_MASK, i);
+}
+
+static int wm831x_buckv_get_current_limit(struct regulator_dev *rdev)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+	u16 reg = dcdc->base + WM831X_DCDC_CONTROL_2;
+	int val;
+
+	val = wm831x_reg_read(wm831x, reg);
+	if (val < 0)
+		return val;
+
+	return wm831x_dcdc_ilim[val & WM831X_DC1_HC_THR_MASK];
+}
+
+static struct regulator_ops wm831x_buckv_ops = {
+	.set_voltage = wm831x_buckv_set_voltage,
+	.get_voltage = wm831x_buckv_get_voltage,
+	.list_voltage = wm831x_buckv_list_voltage,
+	.set_suspend_voltage = wm831x_buckv_set_suspend_voltage,
+	.set_current_limit = wm831x_buckv_set_current_limit,
+	.get_current_limit = wm831x_buckv_get_current_limit,
+
+	.is_enabled = wm831x_dcdc_is_enabled,
+	.enable = wm831x_dcdc_enable,
+	.disable = wm831x_dcdc_disable,
+	.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 __devinit int wm831x_buckv_probe(struct platform_device *pdev)
+{
+	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
+	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 = kzalloc(sizeof(struct wm831x_dcdc), GFP_KERNEL);
+	if (dcdc == NULL) {
+		dev_err(&pdev->dev, "Unable to allocate private data\n");
+		return -ENOMEM;
+	}
+
+	dcdc->wm831x = wm831x;
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "No I/O 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;
+	dcdc->desc.id = id;
+	dcdc->desc.type = REGULATOR_VOLTAGE;
+	dcdc->desc.n_voltages = WM831X_BUCKV_MAX_SELECTOR + 1;
+	dcdc->desc.ops = &wm831x_buckv_ops;
+	dcdc->desc.owner = THIS_MODULE;
+
+	dcdc->regulator = regulator_register(&dcdc->desc, &pdev->dev,
+					     pdata->dcdc[id], dcdc);
+	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 = platform_get_irq_byname(pdev, "UV");
+	ret = wm831x_request_irq(wm831x, irq, wm831x_dcdc_uv_irq,
+				 IRQF_TRIGGER_RISING, dcdc->name,
+				 dcdc);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to request UV IRQ %d: %d\n",
+			irq, ret);
+		goto err_regulator;
+	}
+
+	irq = platform_get_irq_byname(pdev, "HC");
+	ret = wm831x_request_irq(wm831x, irq, wm831x_dcdc_oc_irq,
+				 IRQF_TRIGGER_RISING, dcdc->name,
+				 dcdc);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to request HC IRQ %d: %d\n",
+			irq, ret);
+		goto err_uv;
+	}
+
+	platform_set_drvdata(pdev, dcdc);
+
+	return 0;
+
+err_uv:
+	wm831x_free_irq(wm831x, platform_get_irq_byname(pdev, "UV"), dcdc);
+err_regulator:
+	regulator_unregister(dcdc->regulator);
+err:
+	kfree(dcdc);
+	return ret;
+}
+
+static __devexit int wm831x_buckv_remove(struct platform_device *pdev)
+{
+	struct wm831x_dcdc *dcdc = platform_get_drvdata(pdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+
+	wm831x_free_irq(wm831x, platform_get_irq_byname(pdev, "HC"), dcdc);
+	wm831x_free_irq(wm831x, platform_get_irq_byname(pdev, "UV"), dcdc);
+	regulator_unregister(dcdc->regulator);
+	kfree(dcdc);
+
+	return 0;
+}
+
+static struct platform_driver wm831x_buckv_driver = {
+	.probe = wm831x_buckv_probe,
+	.remove = __devexit_p(wm831x_buckv_remove),
+	.driver		= {
+		.name	= "wm831x-buckv",
+	},
+};
+
+/*
+ * BUCKP specifics
+ */
+
+static int wm831x_buckp_list_voltage(struct regulator_dev *rdev,
+				      unsigned selector)
+{
+	if (selector <= WM831X_BUCKP_MAX_SELECTOR)
+		return 850000 + (selector * 25000);
+	else
+		return -EINVAL;
+}
+
+static int wm831x_buckp_set_voltage_int(struct regulator_dev *rdev, int reg,
+					int min_uV, int max_uV)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+	u16 vsel;
+
+	if (min_uV <= 34000000)
+		vsel = (min_uV - 850000) / 25000;
+	else
+		return -EINVAL;
+
+	if (wm831x_buckp_list_voltage(rdev, vsel) > max_uV)
+		return -EINVAL;
+
+	return wm831x_set_bits(wm831x, reg, WM831X_DC3_ON_VSEL_MASK, vsel);
+}
+
+static int wm831x_buckp_set_voltage(struct regulator_dev *rdev,
+				    int min_uV, int max_uV)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	u16 reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
+
+	return wm831x_buckp_set_voltage_int(rdev, reg, min_uV, max_uV);
+}
+
+static int wm831x_buckp_set_suspend_voltage(struct regulator_dev *rdev,
+					    int uV)
+{
+	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+	u16 reg = dcdc->base + WM831X_DCDC_SLEEP_CONTROL;
+
+	return wm831x_buckp_set_voltage_int(rdev, reg, uV, uV);
+}
+
+static int wm831x_buckp_get_voltage(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;
+
+	return wm831x_buckp_list_voltage(rdev, val & WM831X_DC3_ON_VSEL_MASK);
+}
+
+static struct regulator_ops wm831x_buckp_ops = {
+	.set_voltage = wm831x_buckp_set_voltage,
+	.get_voltage = wm831x_buckp_get_voltage,
+	.list_voltage = wm831x_buckp_list_voltage,
+	.set_suspend_voltage = wm831x_buckp_set_suspend_voltage,
+
+	.is_enabled = wm831x_dcdc_is_enabled,
+	.enable = wm831x_dcdc_enable,
+	.disable = wm831x_dcdc_disable,
+	.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 __devinit int wm831x_buckp_probe(struct platform_device *pdev)
+{
+	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
+	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 = kzalloc(sizeof(struct wm831x_dcdc), GFP_KERNEL);
+	if (dcdc == NULL) {
+		dev_err(&pdev->dev, "Unable to allocate private data\n");
+		return -ENOMEM;
+	}
+
+	dcdc->wm831x = wm831x;
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "No I/O 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;
+	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->regulator = regulator_register(&dcdc->desc, &pdev->dev,
+					     pdata->dcdc[id], dcdc);
+	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 = platform_get_irq_byname(pdev, "UV");
+	ret = wm831x_request_irq(wm831x, irq, wm831x_dcdc_uv_irq,
+				 IRQF_TRIGGER_RISING, dcdc->name,
+				 dcdc);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to request UV IRQ %d: %d\n",
+			irq, ret);
+		goto err_regulator;
+	}
+
+	platform_set_drvdata(pdev, dcdc);
+
+	return 0;
+
+err_regulator:
+	regulator_unregister(dcdc->regulator);
+err:
+	kfree(dcdc);
+	return ret;
+}
+
+static __devexit int wm831x_buckp_remove(struct platform_device *pdev)
+{
+	struct wm831x_dcdc *dcdc = platform_get_drvdata(pdev);
+	struct wm831x *wm831x = dcdc->wm831x;
+
+	wm831x_free_irq(wm831x, platform_get_irq_byname(pdev, "UV"), dcdc);
+	regulator_unregister(dcdc->regulator);
+	kfree(dcdc);
+
+	return 0;
+}
+
+static struct platform_driver wm831x_buckp_driver = {
+	.probe = wm831x_buckp_probe,
+	.remove = __devexit_p(wm831x_buckp_remove),
+	.driver		= {
+		.name	= "wm831x-buckp",
+	},
+};
+
+static int __init wm831x_dcdc_init(void)
+{
+	int ret;
+	ret = platform_driver_register(&wm831x_buckv_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM831x BUCKV driver: %d\n", ret);
+
+	ret = platform_driver_register(&wm831x_buckp_driver);
+	if (ret != 0)
+		pr_err("Failed to register WM831x BUCKP driver: %d\n", ret);
+
+	return 0;
+}
+subsys_initcall(wm831x_dcdc_init);
+
+static void __exit wm831x_dcdc_exit(void)
+{
+	platform_driver_unregister(&wm831x_buckp_driver);
+	platform_driver_unregister(&wm831x_buckv_driver);
+}
+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");