Initial import

1 files changed, 345 insertions, 0 deletions

diff --git a/drivers/regulator/max8952.c b/drivers/regulator/max8952.c
new file mode 100644
index 000000000..1af8f4a2a
--- /dev/null
+++ b/drivers/regulator/max8952.c
@@ -0,0 +1,345 @@
+/*
+ * max8952.c - Voltage and current regulation for the Maxim 8952
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ * MyungJoo Ham <myungjoo.ham@samsung.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/max8952.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+/* Registers */
+enum {
+	MAX8952_REG_MODE0,
+	MAX8952_REG_MODE1,
+	MAX8952_REG_MODE2,
+	MAX8952_REG_MODE3,
+	MAX8952_REG_CONTROL,
+	MAX8952_REG_SYNC,
+	MAX8952_REG_RAMP,
+	MAX8952_REG_CHIP_ID1,
+	MAX8952_REG_CHIP_ID2,
+};
+
+struct max8952_data {
+	struct i2c_client	*client;
+	struct max8952_platform_data *pdata;
+
+	bool vid0;
+	bool vid1;
+};
+
+static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
+{
+	int ret = i2c_smbus_read_byte_data(max8952->client, reg);
+
+	if (ret > 0)
+		ret &= 0xff;
+
+	return ret;
+}
+
+static int max8952_write_reg(struct max8952_data *max8952,
+		u8 reg, u8 value)
+{
+	return i2c_smbus_write_byte_data(max8952->client, reg, value);
+}
+
+static int max8952_list_voltage(struct regulator_dev *rdev,
+		unsigned int selector)
+{
+	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
+
+	if (rdev_get_id(rdev) != 0)
+		return -EINVAL;
+
+	return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
+}
+
+static int max8952_get_voltage_sel(struct regulator_dev *rdev)
+{
+	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
+	u8 vid = 0;
+
+	if (max8952->vid0)
+		vid += 1;
+	if (max8952->vid1)
+		vid += 2;
+
+	return vid;
+}
+
+static int max8952_set_voltage_sel(struct regulator_dev *rdev,
+				   unsigned selector)
+{
+	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
+
+	if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
+			!gpio_is_valid(max8952->pdata->gpio_vid1)) {
+		/* DVS not supported */
+		return -EPERM;
+	}
+
+	max8952->vid0 = selector & 0x1;
+	max8952->vid1 = (selector >> 1) & 0x1;
+	gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
+	gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
+
+	return 0;
+}
+
+static struct regulator_ops max8952_ops = {
+	.list_voltage		= max8952_list_voltage,
+	.get_voltage_sel	= max8952_get_voltage_sel,
+	.set_voltage_sel	= max8952_set_voltage_sel,
+};
+
+static const struct regulator_desc regulator = {
+	.name		= "MAX8952_VOUT",
+	.id		= 0,
+	.n_voltages	= MAX8952_NUM_DVS_MODE,
+	.ops		= &max8952_ops,
+	.type		= REGULATOR_VOLTAGE,
+	.owner		= THIS_MODULE,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id max8952_dt_match[] = {
+	{ .compatible = "maxim,max8952" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max8952_dt_match);
+
+static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
+{
+	struct max8952_platform_data *pd;
+	struct device_node *np = dev->of_node;
+	int ret;
+	int i;
+
+	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		return NULL;
+
+	pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
+	pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
+	pd->gpio_en = of_get_named_gpio(np, "max8952,en-gpio", 0);
+
+	if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
+		dev_warn(dev, "Default mode not specified, assuming 0\n");
+
+	ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
+					pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
+	if (ret) {
+		dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
+		return NULL;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
+		if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
+			dev_err(dev, "DVS voltage %d out of range\n", i);
+			return NULL;
+		}
+		pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
+	}
+
+	if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
+		dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
+
+	if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
+		dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
+
+	pd->reg_data = of_get_regulator_init_data(dev, np, &regulator);
+	if (!pd->reg_data) {
+		dev_err(dev, "Failed to parse regulator init data\n");
+		return NULL;
+	}
+
+	return pd;
+}
+#else
+static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
+{
+	return NULL;
+}
+#endif
+
+static int max8952_pmic_probe(struct i2c_client *client,
+		const struct i2c_device_id *i2c_id)
+{
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct regulator_config config = { };
+	struct max8952_data *max8952;
+	struct regulator_dev *rdev;
+
+	int ret = 0, err = 0;
+
+	if (client->dev.of_node)
+		pdata = max8952_parse_dt(&client->dev);
+
+	if (!pdata) {
+		dev_err(&client->dev, "Require the platform data\n");
+		return -EINVAL;
+	}
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
+		return -EIO;
+
+	max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
+			       GFP_KERNEL);
+	if (!max8952)
+		return -ENOMEM;
+
+	max8952->client = client;
+	max8952->pdata = pdata;
+
+	config.dev = &client->dev;
+	config.init_data = pdata->reg_data;
+	config.driver_data = max8952;
+	config.of_node = client->dev.of_node;
+
+	config.ena_gpio = pdata->gpio_en;
+	if (client->dev.of_node)
+		config.ena_gpio_initialized = true;
+	if (pdata->reg_data->constraints.boot_on)
+		config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
+
+	rdev = devm_regulator_register(&client->dev, &regulator, &config);
+	if (IS_ERR(rdev)) {
+		ret = PTR_ERR(rdev);
+		dev_err(&client->dev, "regulator init failed (%d)\n", ret);
+		return ret;
+	}
+
+	max8952->vid0 = pdata->default_mode & 0x1;
+	max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
+
+	if (gpio_is_valid(pdata->gpio_vid0) &&
+			gpio_is_valid(pdata->gpio_vid1)) {
+		unsigned long gpio_flags;
+
+		gpio_flags = max8952->vid0 ?
+			     GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+		if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0,
+					  gpio_flags, "MAX8952 VID0"))
+			err = 1;
+
+		gpio_flags = max8952->vid1 ?
+			     GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+		if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1,
+					  gpio_flags, "MAX8952 VID1"))
+			err = 2;
+	} else
+		err = 3;
+
+	if (err) {
+		dev_warn(&client->dev, "VID0/1 gpio invalid: "
+				"DVS not available.\n");
+		max8952->vid0 = 0;
+		max8952->vid1 = 0;
+		/* Mark invalid */
+		pdata->gpio_vid0 = -1;
+		pdata->gpio_vid1 = -1;
+
+		/* Disable Pulldown of EN only */
+		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
+
+		dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
+				" do not have proper controls.\n");
+	} else {
+		/*
+		 * Disable Pulldown on EN, VID0, VID1 to reduce
+		 * leakage current of MAX8952 assuming that MAX8952
+		 * is turned on (EN==1). Note that without having VID0/1
+		 * properly connected, turning pulldown off can be
+		 * problematic. Thus, turn this off only when they are
+		 * controllable by GPIO.
+		 */
+		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
+	}
+
+	max8952_write_reg(max8952, MAX8952_REG_MODE0,
+			(max8952_read_reg(max8952,
+					  MAX8952_REG_MODE0) & 0xC0) |
+			(pdata->dvs_mode[0] & 0x3F));
+	max8952_write_reg(max8952, MAX8952_REG_MODE1,
+			(max8952_read_reg(max8952,
+					  MAX8952_REG_MODE1) & 0xC0) |
+			(pdata->dvs_mode[1] & 0x3F));
+	max8952_write_reg(max8952, MAX8952_REG_MODE2,
+			(max8952_read_reg(max8952,
+					  MAX8952_REG_MODE2) & 0xC0) |
+			(pdata->dvs_mode[2] & 0x3F));
+	max8952_write_reg(max8952, MAX8952_REG_MODE3,
+			(max8952_read_reg(max8952,
+					  MAX8952_REG_MODE3) & 0xC0) |
+			(pdata->dvs_mode[3] & 0x3F));
+
+	max8952_write_reg(max8952, MAX8952_REG_SYNC,
+			(max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
+			((pdata->sync_freq & 0x3) << 6));
+	max8952_write_reg(max8952, MAX8952_REG_RAMP,
+			(max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
+			((pdata->ramp_speed & 0x7) << 5));
+
+	i2c_set_clientdata(client, max8952);
+
+	return 0;
+}
+
+static const struct i2c_device_id max8952_ids[] = {
+	{ "max8952", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, max8952_ids);
+
+static struct i2c_driver max8952_pmic_driver = {
+	.probe		= max8952_pmic_probe,
+	.driver		= {
+		.name	= "max8952",
+		.of_match_table = of_match_ptr(max8952_dt_match),
+	},
+	.id_table	= max8952_ids,
+};
+
+static int __init max8952_pmic_init(void)
+{
+	return i2c_add_driver(&max8952_pmic_driver);
+}
+subsys_initcall(max8952_pmic_init);
+
+static void __exit max8952_pmic_exit(void)
+{
+	i2c_del_driver(&max8952_pmic_driver);
+}
+module_exit(max8952_pmic_exit);
+
+MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_LICENSE("GPL");