regulator: enable max8649 regulator driver

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 408 insertions, 0 deletions

diff --git a/drivers/regulator/max8649.c b/drivers/regulator/max8649.c
new file mode 100644
index 000000000000..3ebdf698c648
--- /dev/null
+++ b/drivers/regulator/max8649.c
@@ -0,0 +1,408 @@
+/*
+ * Regulators driver for Maxim max8649
+ *
+ * Copyright (C) 2009-2010 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/max8649.h>
+
+#define MAX8649_DCDC_VMIN	750000		/* uV */
+#define MAX8649_DCDC_VMAX	1380000		/* uV */
+#define MAX8649_DCDC_STEP	10000		/* uV */
+#define MAX8649_VOL_MASK	0x3f
+
+/* Registers */
+#define MAX8649_MODE0		0x00
+#define MAX8649_MODE1		0x01
+#define MAX8649_MODE2		0x02
+#define MAX8649_MODE3		0x03
+#define MAX8649_CONTROL		0x04
+#define MAX8649_SYNC		0x05
+#define MAX8649_RAMP		0x06
+#define MAX8649_CHIP_ID1	0x08
+#define MAX8649_CHIP_ID2	0x09
+
+/* Bits */
+#define MAX8649_EN_PD		(1 << 7)
+#define MAX8649_VID0_PD		(1 << 6)
+#define MAX8649_VID1_PD		(1 << 5)
+#define MAX8649_VID_MASK	(3 << 5)
+
+#define MAX8649_FORCE_PWM	(1 << 7)
+#define MAX8649_SYNC_EXTCLK	(1 << 6)
+
+#define MAX8649_EXT_MASK	(3 << 6)
+
+#define MAX8649_RAMP_MASK	(7 << 5)
+#define MAX8649_RAMP_DOWN	(1 << 1)
+
+struct max8649_regulator_info {
+	struct regulator_dev	*regulator;
+	struct i2c_client	*i2c;
+	struct device		*dev;
+	struct mutex		io_lock;
+
+	int		vol_reg;
+	unsigned	mode:2;	/* bit[1:0] = VID1, VID0 */
+	unsigned	extclk_freq:2;
+	unsigned	extclk:1;
+	unsigned	ramp_timing:3;
+	unsigned	ramp_down:1;
+};
+
+/* I2C operations */
+
+static inline int max8649_read_device(struct i2c_client *i2c,
+				      int reg, int bytes, void *dest)
+{
+	unsigned char data;
+	int ret;
+
+	data = (unsigned char)reg;
+	ret = i2c_master_send(i2c, &data, 1);
+	if (ret < 0)
+		return ret;
+	ret = i2c_master_recv(i2c, dest, bytes);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static inline int max8649_write_device(struct i2c_client *i2c,
+				       int reg, int bytes, void *src)
+{
+	unsigned char buf[bytes + 1];
+	int ret;
+
+	buf[0] = (unsigned char)reg;
+	memcpy(&buf[1], src, bytes);
+
+	ret = i2c_master_send(i2c, buf, bytes + 1);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static int max8649_reg_read(struct i2c_client *i2c, int reg)
+{
+	struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
+	unsigned char data;
+	int ret;
+
+	mutex_lock(&info->io_lock);
+	ret = max8649_read_device(i2c, reg, 1, &data);
+	mutex_unlock(&info->io_lock);
+
+	if (ret < 0)
+		return ret;
+	return (int)data;
+}
+
+static int max8649_set_bits(struct i2c_client *i2c, int reg,
+			    unsigned char mask, unsigned char data)
+{
+	struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
+	unsigned char value;
+	int ret;
+
+	mutex_lock(&info->io_lock);
+	ret = max8649_read_device(i2c, reg, 1, &value);
+	if (ret < 0)
+		goto out;
+	value &= ~mask;
+	value |= data;
+	ret = max8649_write_device(i2c, reg, 1, &value);
+out:
+	mutex_unlock(&info->io_lock);
+	return ret;
+}
+
+static inline int check_range(int min_uV, int max_uV)
+{
+	if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX)
+		|| (min_uV > max_uV))
+		return -EINVAL;
+	return 0;
+}
+
+static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index)
+{
+	return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP);
+}
+
+static int max8649_get_voltage(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	unsigned char data;
+	int ret;
+
+	ret = max8649_reg_read(info->i2c, info->vol_reg);
+	if (ret < 0)
+		return ret;
+	data = (unsigned char)ret & MAX8649_VOL_MASK;
+	return max8649_list_voltage(rdev, data);
+}
+
+static int max8649_set_voltage(struct regulator_dev *rdev,
+			       int min_uV, int max_uV)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	unsigned char data, mask;
+
+	if (check_range(min_uV, max_uV)) {
+		dev_err(info->dev, "invalid voltage range (%d, %d) uV\n",
+			min_uV, max_uV);
+		return -EINVAL;
+	}
+	data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1)
+		/ MAX8649_DCDC_STEP;
+	mask = MAX8649_VOL_MASK;
+
+	return max8649_set_bits(info->i2c, info->vol_reg, mask, data);
+}
+
+/* EN_PD means pulldown on EN input */
+static int max8649_enable(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0);
+}
+
+/*
+ * Applied internal pulldown resistor on EN input pin.
+ * If pulldown EN pin outside, it would be better.
+ */
+static int max8649_disable(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD,
+				MAX8649_EN_PD);
+}
+
+static int max8649_is_enabled(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	int ret;
+
+	ret = max8649_reg_read(info->i2c, MAX8649_CONTROL);
+	if (ret < 0)
+		return ret;
+	return !((unsigned char)ret & MAX8649_EN_PD);
+}
+
+static int max8649_enable_time(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	int voltage, rate, ret;
+
+	/* get voltage */
+	ret = max8649_reg_read(info->i2c, info->vol_reg);
+	if (ret < 0)
+		return ret;
+	ret &= MAX8649_VOL_MASK;
+	voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */
+
+	/* get rate */
+	ret = max8649_reg_read(info->i2c, MAX8649_RAMP);
+	if (ret < 0)
+		return ret;
+	ret = (ret & MAX8649_RAMP_MASK) >> 5;
+	rate = (32 * 1000) >> ret;	/* uV/uS */
+
+	return (voltage / rate);
+}
+
+static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM,
+				 MAX8649_FORCE_PWM);
+		break;
+	case REGULATOR_MODE_NORMAL:
+		max8649_set_bits(info->i2c, info->vol_reg,
+				 MAX8649_FORCE_PWM, 0);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static unsigned int max8649_get_mode(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	int ret;
+
+	ret = max8649_reg_read(info->i2c, info->vol_reg);
+	if (ret & MAX8649_FORCE_PWM)
+		return REGULATOR_MODE_FAST;
+	return REGULATOR_MODE_NORMAL;
+}
+
+static struct regulator_ops max8649_dcdc_ops = {
+	.set_voltage	= max8649_set_voltage,
+	.get_voltage	= max8649_get_voltage,
+	.list_voltage	= max8649_list_voltage,
+	.enable		= max8649_enable,
+	.disable	= max8649_disable,
+	.is_enabled	= max8649_is_enabled,
+	.enable_time	= max8649_enable_time,
+	.set_mode	= max8649_set_mode,
+	.get_mode	= max8649_get_mode,
+
+};
+
+static struct regulator_desc dcdc_desc = {
+	.name		= "max8649",
+	.ops		= &max8649_dcdc_ops,
+	.type		= REGULATOR_VOLTAGE,
+	.n_voltages	= 1 << 6,
+	.owner		= THIS_MODULE,
+};
+
+static int __devinit max8649_regulator_probe(struct i2c_client *client,
+					     const struct i2c_device_id *id)
+{
+	struct max8649_platform_data *pdata = client->dev.platform_data;
+	struct max8649_regulator_info *info = NULL;
+	unsigned char data;
+	int ret;
+
+	info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
+	if (!info) {
+		dev_err(&client->dev, "No enough memory\n");
+		return -ENOMEM;
+	}
+
+	info->i2c = client;
+	info->dev = &client->dev;
+	mutex_init(&info->io_lock);
+	i2c_set_clientdata(client, info);
+
+	info->mode = pdata->mode;
+	switch (info->mode) {
+	case 0:
+		info->vol_reg = MAX8649_MODE0;
+		break;
+	case 1:
+		info->vol_reg = MAX8649_MODE1;
+		break;
+	case 2:
+		info->vol_reg = MAX8649_MODE2;
+		break;
+	case 3:
+		info->vol_reg = MAX8649_MODE3;
+		break;
+	default:
+		break;
+	}
+
+	ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1);
+	if (ret < 0) {
+		dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
+			ret);
+		goto out;
+	}
+	dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret);
+
+	/* enable VID0 & VID1 */
+	max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
+
+	/* enable/disable external clock synchronization */
+	info->extclk = pdata->extclk;
+	data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
+	max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data);
+	if (info->extclk) {
+		/* set external clock frequency */
+		info->extclk_freq = pdata->extclk_freq;
+		max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK,
+				 info->extclk_freq);
+	}
+
+	if (pdata->ramp_timing) {
+		info->ramp_timing = pdata->ramp_timing;
+		max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK,
+				 info->ramp_timing << 5);
+	}
+
+	info->ramp_down = pdata->ramp_down;
+	if (info->ramp_down) {
+		max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN,
+				 MAX8649_RAMP_DOWN);
+	}
+
+	info->regulator = regulator_register(&dcdc_desc, &client->dev,
+					     pdata->regulator, info);
+	if (IS_ERR(info->regulator)) {
+		dev_err(info->dev, "failed to register regulator %s\n",
+			dcdc_desc.name);
+		ret = PTR_ERR(info->regulator);
+		goto out;
+	}
+
+	dev_info(info->dev, "Max8649 regulator device is detected.\n");
+	return 0;
+out:
+	kfree(info);
+	return ret;
+}
+
+static int __devexit max8649_regulator_remove(struct i2c_client *client)
+{
+	struct max8649_regulator_info *info = i2c_get_clientdata(client);
+
+	if (info) {
+		if (info->regulator)
+			regulator_unregister(info->regulator);
+		kfree(info);
+	}
+	i2c_set_clientdata(client, NULL);
+
+	return 0;
+}
+
+static const struct i2c_device_id max8649_id[] = {
+	{ "max8649", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max8649_id);
+
+static struct i2c_driver max8649_driver = {
+	.probe		= max8649_regulator_probe,
+	.remove		= __devexit_p(max8649_regulator_remove),
+	.driver		= {
+		.name	= "max8649",
+	},
+	.id_table	= max8649_id,
+};
+
+static int __init max8649_init(void)
+{
+	return i2c_add_driver(&max8649_driver);
+}
+subsys_initcall(max8649_init);
+
+static void __exit max8649_exit(void)
+{
+	i2c_del_driver(&max8649_driver);
+}
+module_exit(max8649_exit);
+
+/* Module information */
+MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
+