regulator: Add WM8400 regulator support

The WM8400 provides two programmable DCDC step-down (buck) convertors
and four low-dropout (LDO) regulators. This driver provides support for
runtime managment of these in the standard regulator API.

Support for configuration of the suspend and hibernate mode behaviour
of the regulators is not yet included.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

3 files changed, 376 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index a656128f1fdd..99906872cb91 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -56,4 +56,11 @@ config REGULATOR_BQ24022
 	  charging select between 100 mA and 500 mA charging current
 	  limit.
 
+config REGULATOR_WM8400
+	tristate "Wolfson Microelectroncis WM8400 AudioPlus PMIC"
+	depends on MFD_WM8400
+	select REGULATOR
+	help
+	  This driver provides support for the voltage regulators of the
+	  WM8400 AudioPlus PMIC.
 endmenu
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index ac2c64efe65c..3c6ac73af152 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -8,5 +8,6 @@ obj-$(CONFIG_REGULATOR_FIXED_VOLTAGE) += fixed.o
 obj-$(CONFIG_REGULATOR_VIRTUAL_CONSUMER) += virtual.o
 
 obj-$(CONFIG_REGULATOR_BQ24022) += bq24022.o
+obj-$(CONFIG_REGULATOR_WM8400) += wm8400-regulator.o
 
 ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
diff --git a/drivers/regulator/wm8400-regulator.c b/drivers/regulator/wm8400-regulator.c
new file mode 100644
index 000000000000..48b372e038a8
--- /dev/null
+++ b/drivers/regulator/wm8400-regulator.c
@@ -0,0 +1,368 @@
+/*
+ * Regulator support for WM8400
+ *
+ * Copyright 2008 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/bug.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/regulator/driver.h>
+#include <linux/mfd/wm8400-private.h>
+
+static int wm8400_ldo_is_enabled(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	u16 val;
+
+	val = wm8400_reg_read(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev));
+	return (val & WM8400_LDO1_ENA) != 0;
+}
+
+static int wm8400_ldo_enable(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+
+	return wm8400_set_bits(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev),
+			       WM8400_LDO1_ENA, WM8400_LDO1_ENA);
+}
+
+static int wm8400_ldo_disable(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+
+	return wm8400_set_bits(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev),
+			       WM8400_LDO1_ENA, 0);
+}
+
+static int wm8400_ldo_get_voltage(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	u16 val;
+
+	val = wm8400_reg_read(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev));
+	val &= WM8400_LDO1_VSEL_MASK;
+
+	if (val < 15)
+		return 900000 + (val * 50000);
+	else
+		return 1600000 + ((val - 14) * 100000);
+}
+
+static int wm8400_ldo_set_voltage(struct regulator_dev *dev,
+				  int min_uV, int max_uV)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	u16 val;
+
+	if (min_uV < 900000 || min_uV > 3300000)
+		return -EINVAL;
+
+	if (min_uV < 1700000) {
+		/* Steps of 50mV from 900mV;  */
+		val = (min_uV - 850001) / 50000;
+
+		if ((val * 50000) + 900000 > max_uV)
+			return -EINVAL;
+		BUG_ON((val * 50000) + 900000 < min_uV);
+	} else {
+		/* Steps of 100mV from 1700mV */
+		val = ((min_uV - 1600001) / 100000);
+
+		if ((val * 100000) + 1700000 > max_uV)
+			return -EINVAL;
+		BUG_ON((val * 100000) + 1700000 < min_uV);
+
+		val += 0xf;
+	}
+
+	return wm8400_set_bits(wm8400, WM8400_LDO1_CONTROL + rdev_get_id(dev),
+			       WM8400_LDO1_VSEL_MASK, val);
+}
+
+static struct regulator_ops wm8400_ldo_ops = {
+	.is_enabled = wm8400_ldo_is_enabled,
+	.enable = wm8400_ldo_enable,
+	.disable = wm8400_ldo_disable,
+	.get_voltage = wm8400_ldo_get_voltage,
+	.set_voltage = wm8400_ldo_set_voltage,
+};
+
+static int wm8400_dcdc_is_enabled(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
+	u16 val;
+
+	val = wm8400_reg_read(wm8400, WM8400_DCDC1_CONTROL_1 + offset);
+	return (val & WM8400_DC1_ENA) != 0;
+}
+
+static int wm8400_dcdc_enable(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
+
+	return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
+			       WM8400_DC1_ENA, WM8400_DC1_ENA);
+}
+
+static int wm8400_dcdc_disable(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
+
+	return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
+			       WM8400_DC1_ENA, 0);
+}
+
+static int wm8400_dcdc_get_voltage(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	u16 val;
+	int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
+
+	val = wm8400_reg_read(wm8400, WM8400_DCDC1_CONTROL_1 + offset);
+	val &= WM8400_DC1_VSEL_MASK;
+
+	return 850000 + (25000 * val);
+}
+
+static int wm8400_dcdc_set_voltage(struct regulator_dev *dev,
+				  int min_uV, int max_uV)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	u16 val;
+	int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
+
+	if (min_uV < 850000)
+		return -EINVAL;
+
+	val = (min_uV - 825001) / 25000;
+
+	if (850000 + (25000 * val) > max_uV)
+		return -EINVAL;
+	BUG_ON(850000 + (25000 * val) < min_uV);
+
+	return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
+			       WM8400_DC1_VSEL_MASK, val);
+}
+
+static unsigned int wm8400_dcdc_get_mode(struct regulator_dev *dev)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
+	u16 data[2];
+	int ret;
+
+	ret = wm8400_block_read(wm8400, WM8400_DCDC1_CONTROL_1 + offset, 2,
+				data);
+	if (ret != 0)
+		return 0;
+
+	/* Datasheet: hibernate */
+	if (data[0] & WM8400_DC1_SLEEP)
+		return REGULATOR_MODE_STANDBY;
+
+	/* Datasheet: standby */
+	if (!(data[0] & WM8400_DC1_ACTIVE))
+		return REGULATOR_MODE_IDLE;
+
+	/* Datasheet: active with or without force PWM */
+	if (data[1] & WM8400_DC1_FRC_PWM)
+		return REGULATOR_MODE_FAST;
+	else
+		return REGULATOR_MODE_NORMAL;
+}
+
+static int wm8400_dcdc_set_mode(struct regulator_dev *dev, unsigned int mode)
+{
+	struct wm8400 *wm8400 = rdev_get_drvdata(dev);
+	int offset = (rdev_get_id(dev) - WM8400_DCDC1) * 2;
+	int ret;
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		/* Datasheet: active with force PWM */
+		ret = wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_2 + offset,
+				      WM8400_DC1_FRC_PWM, WM8400_DC1_FRC_PWM);
+		if (ret != 0)
+			return ret;
+
+		return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
+				       WM8400_DC1_ACTIVE | WM8400_DC1_SLEEP,
+				       WM8400_DC1_ACTIVE);
+
+	case REGULATOR_MODE_NORMAL:
+		/* Datasheet: active */
+		ret = wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_2 + offset,
+				      WM8400_DC1_FRC_PWM, 0);
+		if (ret != 0)
+			return ret;
+
+		return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
+				       WM8400_DC1_ACTIVE | WM8400_DC1_SLEEP,
+				       WM8400_DC1_ACTIVE);
+
+	case REGULATOR_MODE_IDLE:
+		/* Datasheet: standby */
+		ret = wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
+				      WM8400_DC1_ACTIVE, 0);
+		if (ret != 0)
+			return ret;
+		return wm8400_set_bits(wm8400, WM8400_DCDC1_CONTROL_1 + offset,
+				       WM8400_DC1_SLEEP, 0);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static unsigned int wm8400_dcdc_get_optimum_mode(struct regulator_dev *dev,
+						 int input_uV, int output_uV,
+						 int load_uA)
+{
+	return REGULATOR_MODE_NORMAL;
+}
+
+static struct regulator_ops wm8400_dcdc_ops = {
+	.is_enabled = wm8400_dcdc_is_enabled,
+	.enable = wm8400_dcdc_enable,
+	.disable = wm8400_dcdc_disable,
+	.get_voltage = wm8400_dcdc_get_voltage,
+	.set_voltage = wm8400_dcdc_set_voltage,
+	.get_mode = wm8400_dcdc_get_mode,
+	.set_mode = wm8400_dcdc_set_mode,
+	.get_optimum_mode = wm8400_dcdc_get_optimum_mode,
+};
+
+static struct regulator_desc regulators[] = {
+	{
+		.name = "LDO1",
+		.id = WM8400_LDO1,
+		.ops = &wm8400_ldo_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "LDO2",
+		.id = WM8400_LDO2,
+		.ops = &wm8400_ldo_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "LDO3",
+		.id = WM8400_LDO3,
+		.ops = &wm8400_ldo_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "LDO4",
+		.id = WM8400_LDO4,
+		.ops = &wm8400_ldo_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "DCDC1",
+		.id = WM8400_DCDC1,
+		.ops = &wm8400_dcdc_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+	{
+		.name = "DCDC2",
+		.id = WM8400_DCDC2,
+		.ops = &wm8400_dcdc_ops,
+		.type = REGULATOR_VOLTAGE,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init wm8400_regulator_probe(struct platform_device *pdev)
+{
+	struct regulator_dev *rdev;
+
+	rdev = regulator_register(&regulators[pdev->id], &pdev->dev,
+		pdev->dev.driver_data);
+
+	if (IS_ERR(rdev))
+		return PTR_ERR(rdev);
+
+	return 0;
+}
+
+static int __devexit wm8400_regulator_remove(struct platform_device *pdev)
+{
+	struct regulator_dev *rdev = platform_get_drvdata(pdev);
+
+	regulator_unregister(rdev);
+
+	return 0;
+}
+
+static struct platform_driver wm8400_regulator_driver = {
+	.driver = {
+		.name = "wm8400-regulator",
+	},
+	.probe = wm8400_regulator_probe,
+	.remove = __devexit_p(wm8400_regulator_remove),
+};
+
+/**
+ * wm8400_register_regulator - enable software control of a WM8400 regulator
+ *
+ * This function enables software control of a WM8400 regulator via
+ * the regulator API.  It is intended to be called from the
+ * platform_init() callback of the WM8400 MFD driver.
+ *
+ * @param dev      The WM8400 device to operate on.
+ * @param reg      The regulator to control.
+ * @param initdata Regulator initdata for the regulator.
+ */
+int wm8400_register_regulator(struct device *dev, int reg,
+			      struct regulator_init_data *initdata)
+{
+	struct wm8400 *wm8400 = dev->driver_data;
+
+	if (wm8400->regulators[reg].name)
+		return -EBUSY;
+
+	initdata->driver_data = wm8400;
+
+	wm8400->regulators[reg].name = "wm8400-regulator";
+	wm8400->regulators[reg].id = reg;
+	wm8400->regulators[reg].dev.parent = dev;
+	wm8400->regulators[reg].dev.driver_data = wm8400;
+	wm8400->regulators[reg].dev.platform_data = initdata;
+
+	return platform_device_register(&wm8400->regulators[reg]);
+}
+EXPORT_SYMBOL_GPL(wm8400_register_regulator);
+
+static int __init wm8400_regulator_init(void)
+{
+	return platform_driver_register(&wm8400_regulator_driver);
+}
+module_init(wm8400_regulator_init);
+
+static void __exit wm8400_regulator_exit(void)
+{
+	platform_driver_unregister(&wm8400_regulator_driver);
+}
+module_exit(wm8400_regulator_exit);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("WM8400 regulator driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm8400-regulator");