regulator: tps51632: Add tps51632 regulator driver

The TPS51632 is a driverless step down controller with
serial control. Advanced features such as D-Cap+
architecture with overlapping pulse support and OSR
overshoot reduction provide fast transient response,
lowest output capacitance and high efficiency.
The TPS51632 supports both I2C and DVFS interfaces
(through PWM) for dynamic control of the output voltage
and current monitor telemetry.
Add regulator driver for TPS51632.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

3 files changed, 344 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 67d47b59..aa9e8a1 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -335,6 +335,17 @@ config REGULATOR_PALMAS
 	  on the muxing. This is handled automatically in the driver by
 	  reading the mux info from OTP.
 
+config REGULATOR_TPS51632
+	tristate "TI TPS51632 Power Regulator"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This driver supports TPS51632 voltage regulator chip.
+	  The TPS52632 is 3-2-1 Phase D-Cap+ Step Down Driverless Controller
+	  with Serial VID control and DVFS.
+	  The voltage output can be configure through I2C interface or PWM
+	  interface.
+
 config REGULATOR_TPS6105X
 	tristate "TI TPS6105X Power regulators"
 	depends on TPS6105X
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index e431eed..ec1aec4 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_REGULATOR_MC13783) += mc13783-regulator.o
 obj-$(CONFIG_REGULATOR_MC13892) += mc13892-regulator.o
 obj-$(CONFIG_REGULATOR_MC13XXX_CORE) +=  mc13xxx-regulator-core.o
 obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o
+obj-$(CONFIG_REGULATOR_TPS51632) += tps51632-regulator.o
 obj-$(CONFIG_REGULATOR_PCAP) += pcap-regulator.o
 obj-$(CONFIG_REGULATOR_PCF50633) += pcf50633-regulator.o
 obj-$(CONFIG_REGULATOR_RC5T583)  += rc5t583-regulator.o
diff --git a/drivers/regulator/tps51632-regulator.c b/drivers/regulator/tps51632-regulator.c
new file mode 100644
index 0000000..34603640d
--- /dev/null
+++ b/drivers/regulator/tps51632-regulator.c
@@ -0,0 +1,332 @@
+/*
+ * tps51632-regulator.c -- TI TPS51632
+ *
+ * Regulator driver for TPS51632 3-2-1 Phase D-Cap Step Down Driverless
+ * Controller with serial VID control and DVFS.
+ *
+ * Copyright (c) 2012, NVIDIA Corporation.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; 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/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/tps51632-regulator.h>
+#include <linux/slab.h>
+
+/* Register definitions */
+#define TPS51632_VOLTAGE_SELECT_REG		0x0
+#define TPS51632_VOLTAGE_BASE_REG		0x1
+#define TPS51632_OFFSET_REG			0x2
+#define TPS51632_IMON_REG			0x3
+#define TPS51632_VMAX_REG			0x4
+#define TPS51632_DVFS_CONTROL_REG		0x5
+#define TPS51632_POWER_STATE_REG		0x6
+#define TPS51632_SLEW_REGS			0x7
+#define TPS51632_FAULT_REG			0x14
+
+#define TPS51632_MAX_REG			0x15
+
+#define TPS51632_VOUT_MASK			0x7F
+#define TPS51632_VOUT_OFFSET_MASK		0x1F
+#define TPS51632_VMAX_MASK			0x7F
+#define TPS51632_VMAX_LOCK			0x80
+
+/* TPS51632_DVFS_CONTROL_REG */
+#define TPS51632_DVFS_PWMEN			0x1
+#define TPS51632_DVFS_STEP_20			0x2
+#define TPS51632_DVFS_VMAX_PG			0x4
+#define TPS51632_DVFS_PWMRST			0x8
+#define TPS51632_DVFS_OCA_EN			0x10
+#define TPS51632_DVFS_FCCM			0x20
+
+/* TPS51632_POWER_STATE_REG */
+#define TPS51632_POWER_STATE_MASK		0x03
+#define TPS51632_POWER_STATE_MULTI_PHASE_CCM	0x0
+#define TPS51632_POWER_STATE_SINGLE_PHASE_CCM	0x1
+#define TPS51632_POWER_STATE_SINGLE_PHASE_DCM	0x2
+
+#define TPS51632_MIN_VOLATGE			500000
+#define TPS51632_MAX_VOLATGE			1520000
+#define TPS51632_VOLATGE_STEP_10mV		10000
+#define TPS51632_VOLATGE_STEP_20mV		20000
+#define TPS51632_MAX_VSEL			0x7F
+#define TPS51632_MIN_VSEL			0x19
+#define TPS51632_DEFAULT_RAMP_DELAY		6000
+#define TPS51632_VOLT_VSEL(uV)					\
+		(DIV_ROUND_UP(uV - TPS51632_MIN_VOLATGE,	\
+			TPS51632_VOLATGE_STEP_10mV) +		\
+			TPS51632_MIN_VSEL)
+
+/* TPS51632 chip information */
+struct tps51632_chip {
+	struct device *dev;
+	struct regulator_desc desc;
+	struct regulator_dev *rdev;
+	struct regmap *regmap;
+	bool enable_pwm_dvfs;
+};
+
+static int tps51632_dcdc_get_voltage_sel(struct regulator_dev *rdev)
+{
+	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
+	unsigned int data;
+	int ret;
+	unsigned int reg = TPS51632_VOLTAGE_SELECT_REG;
+	int vsel;
+
+	if (tps->enable_pwm_dvfs)
+		reg = TPS51632_VOLTAGE_BASE_REG;
+
+	ret = regmap_read(tps->regmap, reg, &data);
+	if (ret < 0) {
+		dev_err(tps->dev, "reg read failed, err %d\n", ret);
+		return ret;
+	}
+
+	vsel = data & TPS51632_VOUT_MASK;
+
+	if (vsel < TPS51632_MIN_VSEL)
+		return 0;
+	else
+		return vsel - TPS51632_MIN_VSEL;
+}
+
+static int tps51632_dcdc_set_voltage_sel(struct regulator_dev *rdev,
+		unsigned selector)
+{
+	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
+	int vsel;
+	int ret;
+	unsigned int reg = TPS51632_VOLTAGE_SELECT_REG;
+
+	if (tps->enable_pwm_dvfs)
+		reg = TPS51632_VOLTAGE_BASE_REG;
+
+	vsel = selector + TPS51632_MIN_VSEL;
+	if (vsel > TPS51632_MAX_VSEL)
+		return -EINVAL;
+
+	ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_SELECT_REG, vsel);
+	if (ret < 0)
+		dev_err(tps->dev, "reg write failed, err %d\n", ret);
+	return ret;
+}
+
+static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
+		int ramp_delay)
+{
+	struct tps51632_chip *tps = rdev_get_drvdata(rdev);
+	int bit = ramp_delay/6000;
+	int ret;
+
+	if (bit)
+		bit--;
+	ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
+	if (ret < 0)
+		dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);
+	return ret;
+}
+
+static struct regulator_ops tps51632_dcdc_ops = {
+	.get_voltage_sel	= tps51632_dcdc_get_voltage_sel,
+	.set_voltage_sel	= tps51632_dcdc_set_voltage_sel,
+	.list_voltage		= regulator_list_voltage_linear,
+	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
+	.set_ramp_delay		= tps51632_dcdc_set_ramp_delay,
+};
+
+static int __devinit tps51632_init_dcdc(struct tps51632_chip *tps,
+		struct tps51632_regulator_platform_data *pdata)
+{
+	int ret;
+	uint8_t	control = 0;
+	int vsel;
+
+	if (!pdata->enable_pwm_dvfs)
+		goto skip_pwm_config;
+
+	control |= TPS51632_DVFS_PWMEN;
+	tps->enable_pwm_dvfs = pdata->enable_pwm_dvfs;
+	vsel = TPS51632_VOLT_VSEL(pdata->base_voltage_uV);
+	ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_BASE_REG, vsel);
+	if (ret < 0) {
+		dev_err(tps->dev, "BASE reg write failed, err %d\n", ret);
+		return ret;
+	}
+
+	if (pdata->dvfs_step_20mV)
+		control |= TPS51632_DVFS_STEP_20;
+
+	if (pdata->max_voltage_uV) {
+		unsigned int vmax;
+		/**
+		 * TPS51632 hw behavior: VMAX register can be write only
+		 * once as it get locked after first write. The lock get
+		 * reset only when device is power-reset.
+		 * Write register only when lock bit is not enabled.
+		 */
+		ret = regmap_read(tps->regmap, TPS51632_VMAX_REG, &vmax);
+		if (ret < 0) {
+			dev_err(tps->dev, "VMAX read failed, err %d\n", ret);
+			return ret;
+		}
+		if (!(vmax & TPS51632_VMAX_LOCK)) {
+			vsel = TPS51632_VOLT_VSEL(pdata->max_voltage_uV);
+			ret = regmap_write(tps->regmap, TPS51632_VMAX_REG,
+					vsel);
+			if (ret < 0) {
+				dev_err(tps->dev,
+					"VMAX write failed, err %d\n", ret);
+				return ret;
+			}
+		}
+	}
+
+skip_pwm_config:
+	ret = regmap_write(tps->regmap, TPS51632_DVFS_CONTROL_REG, control);
+	if (ret < 0)
+		dev_err(tps->dev, "DVFS reg write failed, err %d\n", ret);
+	return ret;
+}
+
+static bool rd_wr_reg(struct device *dev, unsigned int reg)
+{
+	if ((reg >= 0x8) && (reg <= 0x10))
+		return false;
+	return true;
+}
+
+static const struct regmap_config tps51632_regmap_config = {
+	.reg_bits		= 8,
+	.val_bits		= 8,
+	.writeable_reg		= rd_wr_reg,
+	.readable_reg		= rd_wr_reg,
+	.max_register		= TPS51632_MAX_REG - 1,
+	.cache_type		= REGCACHE_RBTREE,
+};
+
+static int __devinit tps51632_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct tps51632_regulator_platform_data *pdata;
+	struct regulator_dev *rdev;
+	struct tps51632_chip *tps;
+	int ret;
+	struct regulator_config config = { };
+
+	pdata = client->dev.platform_data;
+	if (!pdata) {
+		dev_err(&client->dev, "No Platform data\n");
+		return -EINVAL;
+	}
+
+	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
+	if (!tps) {
+		dev_err(&client->dev, "Memory allocation failed\n");
+		return -ENOMEM;
+	}
+
+	tps->dev = &client->dev;
+	tps->desc.name = id->name;
+	tps->desc.id = 0;
+	tps->desc.ramp_delay = TPS51632_DEFAULT_RAMP_DELAY;
+	tps->desc.min_uV = TPS51632_MIN_VOLATGE;
+	tps->desc.uV_step = TPS51632_VOLATGE_STEP_10mV;
+	tps->desc.n_voltages = (TPS51632_MAX_VSEL - TPS51632_MIN_VSEL) + 1;
+	tps->desc.ops = &tps51632_dcdc_ops;
+	tps->desc.type = REGULATOR_VOLTAGE;
+	tps->desc.owner = THIS_MODULE;
+
+	tps->regmap = devm_regmap_init_i2c(client, &tps51632_regmap_config);
+	if (IS_ERR(tps->regmap)) {
+		ret = PTR_ERR(tps->regmap);
+		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
+		return ret;
+	}
+	i2c_set_clientdata(client, tps);
+
+	ret = tps51632_init_dcdc(tps, pdata);
+	if (ret < 0) {
+		dev_err(tps->dev, "Init failed, err = %d\n", ret);
+		return ret;
+	}
+
+	/* Register the regulators */
+	config.dev = &client->dev;
+	config.init_data = pdata->reg_init_data;
+	config.driver_data = tps;
+	config.regmap = tps->regmap;
+	config.of_node = client->dev.of_node;
+
+	rdev = regulator_register(&tps->desc, &config);
+	if (IS_ERR(rdev)) {
+		dev_err(tps->dev, "regulator register failed\n");
+		return PTR_ERR(rdev);
+	}
+
+	tps->rdev = rdev;
+	return 0;
+}
+
+static int __devexit tps51632_remove(struct i2c_client *client)
+{
+	struct tps51632_chip *tps = i2c_get_clientdata(client);
+
+	regulator_unregister(tps->rdev);
+	return 0;
+}
+
+static const struct i2c_device_id tps51632_id[] = {
+	{.name = "tps51632",},
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, tps51632_id);
+
+static struct i2c_driver tps51632_i2c_driver = {
+	.driver = {
+		.name = "tps51632",
+		.owner = THIS_MODULE,
+	},
+	.probe = tps51632_probe,
+	.remove = __devexit_p(tps51632_remove),
+	.id_table = tps51632_id,
+};
+
+static int __init tps51632_init(void)
+{
+	return i2c_add_driver(&tps51632_i2c_driver);
+}
+subsys_initcall(tps51632_init);
+
+static void __exit tps51632_cleanup(void)
+{
+	i2c_del_driver(&tps51632_i2c_driver);
+}
+module_exit(tps51632_cleanup);
+
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_DESCRIPTION("TPS51632 voltage regulator driver");
+MODULE_LICENSE("GPL v2");