regulator: tps6236x: Adding driver

Adding regulator driver for the device TPS6236x.

bug 821295

Change-Id: Ifed4044db33fa6867248fae000bddf6239cb9685
Reviewed-on: http://git-master/r/31386
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Laxman Dewangan <ldewangan@nvidia.com>

4 files changed, 494 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index b9ecf8028ef1..aad898c62e7d 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -258,6 +258,12 @@ config REGULATOR_TPS6591X
 	help
 	  This driver supports TPS6591X voltage regulator chips.
 
+config REGULATOR_TPS6236X
+	tristate "TI TPS6236X DC-DC core power suply regulators"
+	default n
+	help
+	  This driver supports TPS6236X DC-DC Processor core supply.
+
 config REGULATOR_GPIO_SWITCH
 	bool "GPIO based enable/disable of power rails."
 	default n
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index d63ed3d9d410..33c6bffc3b89 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
 
 obj-$(CONFIG_REGULATOR_TPS65023) += tps65023-regulator.o
 obj-$(CONFIG_REGULATOR_TPS6507X) += tps6507x-regulator.o
+obj-$(CONFIG_REGULATOR_TPS6236X) += tps6236x-regulator.o
 obj-$(CONFIG_REGULATOR_88PM8607) += 88pm8607.o
 obj-$(CONFIG_REGULATOR_ISL6271A) += isl6271a-regulator.o
 obj-$(CONFIG_REGULATOR_AB8500)	+= ab8500.o
diff --git a/drivers/regulator/tps6236x-regulator.c b/drivers/regulator/tps6236x-regulator.c
new file mode 100644
index 000000000000..e0d45487252d
--- /dev/null
+++ b/drivers/regulator/tps6236x-regulator.c
@@ -0,0 +1,439 @@
+/*
+ * driver/regultor/tps6236x.c
+ *
+ * Driver for processor core supply tps62360 and tps62361B
+ *
+ * Copyright (c) 2011, NVIDIA Corporation.
+ *
+ * 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
+ */
+
+/*#define DEBUG		1*/
+/*#define VERBOSE_DEBUG	1*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/tps6236x-regulator.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+
+/* Register definitions */
+#define REG_VSET0		0
+#define REG_VSET1		1
+#define REG_VSET2		2
+#define REG_VSET3		3
+#define REG_CONTROL		4
+#define REG_TEMP		5
+#define REG_RAMPCTRL		6
+#define REG_CHIPID		8
+
+enum chips {TPS62360, TPS62361B};
+
+/* Supported voltage values for regulators */
+static const u16 TPS62360_VOLTAGES[] = {
+	 770,  780,  790,  800,  810,  820,  830,  840,  850,  860,
+	 870,  880,  890,  900,  910,  920,  930,  940,  950,  960,
+	 970,  980,  990, 1000, 1010, 1020, 1030, 1040, 1050, 1060,
+	1070, 1080, 1090, 1110, 1110, 1120, 1130, 1140, 1150, 1160,
+	1170, 1180, 1190, 1200, 1210, 1220, 1230, 1240, 1250, 1260,
+	1270, 1280, 1290, 1300, 1310, 1320, 1330, 1340, 1350, 1360,
+	1370, 1380, 1390, 1400,
+};
+
+static const u16 TPS62361_VOLTAGES[] = {
+	 500,  510,  520,  530,  540,  550,  560,  570,  580,  590,
+	 600,  610,  620,  630,  640,  650,  660,  670,  680,  690,
+	 700,  710,  720,  730,  740,  750,  760,  770,  780,  790,
+	 800,  810,  820,  830,  840,  850,  860,  870,  880,  890,
+	 900,  910,  920,  930,  940,  950,  960,  970,  980,  990,
+	1000, 1010, 1020, 1030, 1040, 1050, 1060, 1070, 1080, 1090,
+	1110, 1110, 1120, 1130, 1140, 1150, 1160, 1170, 1180, 1190,
+	1200, 1210, 1220, 1230, 1240, 1250, 1260, 1270, 1280, 1290,
+	1300, 1310, 1320, 1330, 1340, 1350, 1360, 1370, 1380, 1390,
+	1400, 1410, 1420, 1430, 1440, 1450, 1460, 1470, 1480, 1490,
+	1500, 1510, 1520, 1530, 1540, 1550, 1560, 1570, 1580, 1590,
+	1600, 1610, 1620, 1630, 1640, 1650, 1660, 1670, 1680, 1690,
+	1700, 1710, 1720, 1730, 1740, 1750, 1760, 1770,
+};
+
+/* tps 6236x chip information */
+struct tps6236x_chip {
+	const char *name;
+	struct device *dev;
+	struct regulator_desc desc;
+	struct i2c_client *client;
+	struct regulator_dev *rdev;
+	struct mutex io_lock;
+	int chip_id;
+	unsigned int curr_uV;
+	int vsel_id;
+	int internal_pulldn_en;
+	const u16 *voltages;
+	u8 voltage_reg_mask;
+};
+static inline int tps6236x_read(struct tps6236x_chip *tps, u8 reg)
+{
+	return i2c_smbus_read_byte_data(tps->client, reg);
+}
+
+static inline int tps6236x_write(struct tps6236x_chip *tps, u8 reg, u8 val)
+{
+	return i2c_smbus_write_byte_data(tps->client, reg, val);
+}
+
+static int tps6236x_reg_read(struct tps6236x_chip *tps, u8 reg)
+{
+	int data;
+
+	mutex_lock(&tps->io_lock);
+
+	data = tps6236x_read(tps, reg);
+	if (data < 0)
+		dev_err(tps->dev, "Read from reg 0x%x failed\n", reg);
+
+	mutex_unlock(&tps->io_lock);
+
+	return data;
+}
+
+static int tps6236x_reg_write(struct tps6236x_chip *tps, u8 reg, u8 val)
+{
+	int err;
+
+	mutex_lock(&tps->io_lock);
+
+	err = tps6236x_write(tps, reg, val);
+	if (err < 0)
+		dev_err(tps->dev, "Write for reg 0x%x failed\n", reg);
+
+	mutex_unlock(&tps->io_lock);
+
+	return err;
+}
+static int __tps6236x_dcdc_set_voltage(struct tps6236x_chip *tps,
+				int min_uV, int max_uV)
+{
+	int vsel;
+
+	if (max_uV < min_uV)
+		return -EINVAL;
+
+	if (min_uV > tps->voltages[tps->desc.n_voltages - 1] * 1000)
+		return -EINVAL;
+
+	if (max_uV < tps->voltages[0] * 1000)
+		return -EINVAL;
+
+	for (vsel = 0; vsel < tps->desc.n_voltages; ++vsel) {
+		int mV = tps->voltages[vsel];
+		int uV = mV * 1000;
+		if (min_uV <= uV && uV <= max_uV) {
+			return tps6236x_reg_write(tps, REG_VSET0 + tps->vsel_id,
+					vsel);
+		}
+	}
+	return -EINVAL;
+}
+
+static int tps6236x_dcdc_is_enabled(struct regulator_dev *dev)
+{
+	/* Always return 1 as the EN is not controlled by register
+	   programming */
+	return 1;
+}
+
+static int tps6236x_dcdc_enable(struct regulator_dev *dev)
+{
+	/* No way to enable dc-dc converter through register programming */
+	return 0;
+
+}
+
+static int tps6236x_dcdc_disable(struct regulator_dev *dev)
+{
+	/* No way to disable dc-dc converter through register programming */
+	return 0;
+}
+
+static int tps6236x_dcdc_get_voltage(struct regulator_dev *dev)
+{
+	struct tps6236x_chip *tps = rdev_get_drvdata(dev);
+	int data;
+
+	data = tps6236x_reg_read(tps, REG_VSET0 + tps->vsel_id);
+	if (data < 0)
+		return data;
+	data &= tps->voltage_reg_mask;
+
+	return tps->voltages[data] * 1000;
+}
+
+static int tps6236x_dcdc_set_voltage(struct regulator_dev *dev,
+				int min_uV, int max_uV)
+{
+	struct tps6236x_chip *tps = rdev_get_drvdata(dev);
+
+	return __tps6236x_dcdc_set_voltage(tps, min_uV, max_uV);
+}
+
+static int tps6236x_dcdc_list_voltage(struct regulator_dev *dev,
+					unsigned selector)
+{
+	struct tps6236x_chip *tps = rdev_get_drvdata(dev);
+
+	if ((selector < 0) || (selector >= tps->desc.n_voltages))
+		return -EINVAL;
+
+	return tps->voltages[selector] * 1000;
+}
+
+/* Operations permitted on VDCDCx */
+static struct regulator_ops tps6236x_dcdc_ops = {
+	.is_enabled = tps6236x_dcdc_is_enabled,
+	.enable = tps6236x_dcdc_enable,
+	.disable = tps6236x_dcdc_disable,
+	.get_voltage = tps6236x_dcdc_get_voltage,
+	.set_voltage = tps6236x_dcdc_set_voltage,
+	.list_voltage = tps6236x_dcdc_list_voltage,
+};
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+static void print_regs(const char *header, struct seq_file *s,
+		struct tps6236x_chip *tps, int start_offset,
+		int end_offset)
+{
+	int reg_val;
+	int i;
+
+	seq_printf(s, "%s\n", header);
+	for (i = start_offset; i <= end_offset; ++i) {
+		reg_val = tps6236x_reg_read(tps, i);
+		if (reg_val >= 0)
+			seq_printf(s, "Reg 0x%02x Value 0x%02x\n", i, reg_val);
+	}
+	seq_printf(s, "------------------\n");
+}
+
+static int dbg_tps_show(struct seq_file *s, void *unused)
+{
+	struct tps6236x_chip *tps = s->private;
+
+	seq_printf(s, "TPS6236x Registers\n");
+	seq_printf(s, "------------------\n");
+
+	print_regs("Voltage Regs",  s, tps, 0x0, 0x3);
+	print_regs("Config Regs",   s, tps, 0x4, 0x6);
+	print_regs("ManId Regs",    s, tps, 0x8, 0x9);
+	return 0;
+}
+
+static int dbg_tps_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dbg_tps_show, inode->i_private);
+}
+
+static const struct file_operations debug_fops = {
+	.open		= dbg_tps_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void __init tps6236x_debuginit(struct tps6236x_chip *tps)
+{
+	(void)debugfs_create_file("tps6236x", S_IRUGO, NULL,
+			tps, &debug_fops);
+}
+#else
+static void __init tps6236x_debuginit(struct tps6236x_chip *tps)
+{
+	return;
+}
+#endif
+static int tps6236x_init_dcdc(struct i2c_client *client,
+		struct tps6236x_regulator_platform_data *pdata,
+		struct tps6236x_chip *tps)
+{
+	int st;
+	int init_mV;
+
+	if (pdata->internal_pd_enable)
+		st = tps6236x_write(tps, REG_CONTROL, 0xE0);
+	else
+		st = tps6236x_write(tps, REG_CONTROL, 0x0);
+	if (st < 0)
+		return st;
+
+	if (!pdata->init_apply)
+		return 0;
+
+	init_mV = pdata->init_uV;
+	return __tps6236x_dcdc_set_voltage(tps, init_mV, init_mV);
+}
+
+static int __devinit tps6236x_probe(struct i2c_client *client,
+				     const struct i2c_device_id *id)
+{
+	struct tps6236x_regulator_platform_data *pdata;
+	struct regulator_init_data *init_data;
+	struct regulator_dev *rdev;
+	struct tps6236x_chip *tps;
+	int err;
+	int chip_id;
+	int part_id;
+
+	dev_dbg(&client->dev, "%s() is called\n", __func__);
+	if (!i2c_check_functionality(client->adapter,
+				I2C_FUNC_SMBUS_BYTE_DATA)) {
+		dev_err(&client->dev, "Err: The I2c functionality is"
+					" not supported\n");
+		return -EIO;
+	}
+
+	/**
+	 * init_data points to array of regulator_init structures
+	 * coming from the board-evm file.
+	 */
+	pdata = client->dev.platform_data;
+	if (!pdata) {
+		dev_err(&client->dev, "Err: Platform data not found\n");
+		return -EIO;
+	}
+
+	init_data = &pdata->reg_init_data;
+	tps = kzalloc(sizeof(*tps), GFP_KERNEL);
+	if (!tps) {
+		dev_err(&client->dev, "Err: Memory allocation fails\n");
+		return -ENOMEM;
+	}
+
+	mutex_init(&tps->io_lock);
+
+	tps->chip_id = id->driver_data;
+	tps->client = client;
+	tps->dev = &client->dev;
+	tps->internal_pulldn_en = pdata->internal_pd_enable;
+	tps->vsel_id = pdata->vsel;
+	tps->name = id->name;
+	tps->voltages = (tps->chip_id == TPS62360) ?
+				TPS62360_VOLTAGES : TPS62361_VOLTAGES;
+	tps->voltage_reg_mask = (tps->chip_id == TPS62360) ? 0x3F : 0x7F;
+
+	tps->desc.name = id->name;
+	tps->desc.id = 0;
+	tps->desc.n_voltages = (tps->chip_id == TPS62360) ?
+				ARRAY_SIZE(TPS62360_VOLTAGES) :
+				ARRAY_SIZE(TPS62361_VOLTAGES);
+	tps->desc.ops = &tps6236x_dcdc_ops;
+	tps->desc.type = REGULATOR_VOLTAGE;
+	tps->desc.owner = THIS_MODULE;
+
+	i2c_set_clientdata(client, tps);
+
+	/* Read version number and compare with chipid */
+	chip_id = tps6236x_read(tps, REG_CHIPID);
+	if (chip_id < 0) {
+		err = chip_id;
+		dev_err(tps->dev, "Error in reading device %d\n", err);
+		goto fail;
+	}
+	part_id = (chip_id >> 2) & 0x3;
+	if (((part_id == 0) && (tps->chip_id != TPS62360)) ||
+		((part_id == 1) && (tps->chip_id != TPS62361B)) ||
+		(part_id == 2) || (part_id == 3)) {
+		dev_err(tps->dev, "Err: Mismatch of partid and driver chip-id"
+				  " 0x%x\n", chip_id);
+		err = -ENODEV;
+		goto fail;
+	}
+
+	err = tps6236x_init_dcdc(client, pdata, tps);
+	if (err < 0) {
+		dev_err(tps->dev, "TPS6236X init fails with = %d\n", err);
+		goto fail;
+	}
+
+	/* Register the regulators */
+	rdev = regulator_register(&tps->desc, &client->dev, init_data, tps);
+	if (IS_ERR(rdev)) {
+		dev_err(tps->dev, "Failed to register %s\n", id->name);
+		err = PTR_ERR(rdev);
+		goto fail;
+	}
+
+	tps->rdev = rdev;
+
+	tps6236x_debuginit(tps);
+	return 0;
+
+fail:
+	kfree(tps);
+	return err;
+}
+
+/**
+ * tps6236x_remove - tps6236x driver i2c remove handler
+ * @client: i2c driver client device structure
+ *
+ * Unregister TPS driver as an i2c client device driver
+ */
+static int __devexit tps6236x_remove(struct i2c_client *client)
+{
+	struct tps6236x_chip *tps = i2c_get_clientdata(client);
+
+	regulator_unregister(tps->rdev);
+	kfree(tps);
+	return 0;
+}
+
+static const struct i2c_device_id tps6236x_id[] = {
+	{.name = "tps62360",  .driver_data = TPS62360},
+	{.name = "tps62361B", .driver_data = TPS62361B},
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, tps6236x_id);
+
+static struct i2c_driver tps6236x_i2c_driver = {
+	.driver = {
+		.name = "tps6236x",
+		.owner = THIS_MODULE,
+	},
+	.probe = tps6236x_probe,
+	.remove = __devexit_p(tps6236x_remove),
+	.id_table = tps6236x_id,
+};
+
+/* Module init function */
+static int __init tps6236x_init(void)
+{
+	return i2c_add_driver(&tps6236x_i2c_driver);
+}
+subsys_initcall_sync(tps6236x_init);
+
+/* Module exit function */
+static void __exit tps6236x_cleanup(void)
+{
+	i2c_del_driver(&tps6236x_i2c_driver);
+}
+module_exit(tps6236x_cleanup);
diff --git a/include/linux/regulator/tps6236x-regulator.h b/include/linux/regulator/tps6236x-regulator.h
new file mode 100644
index 000000000000..d06ace99ce1f
--- /dev/null
+++ b/include/linux/regulator/tps6236x-regulator.h
@@ -0,0 +1,48 @@
+/*
+ * include/linux/regulator/tps6236x.h
+ *
+ * Interface for regulator driver for TI TPS6236x Processor core supply
+ *
+ * Copyright (C) 2011 NVIDIA Corporation
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA	02110-1301, USA.
+ *
+ */
+
+#ifndef __REGULATOR_TPS6236X_H
+#define __REGULATOR_TPS6236X_H
+
+#include <linux/regulator/machine.h>
+
+/*
+ * struct tps6236x_regulator_platform_data - tps6236x regulator platform data.
+ *
+ * @reg_init_data: The regulator init data.
+ * @internal_pd_enable: internal pull down enable or not.
+ * @vsel: Select the voltage id register.
+ * @init_uV: initial micro volts which need to be set.
+ * @init_enable: Enable or do not enable the rails during initialization.
+ * @init_apply: Init parameter applied or not.
+ */
+
+struct tps6236x_regulator_platform_data {
+	struct regulator_init_data reg_init_data;
+	int internal_pd_enable;
+	int vsel;
+	int init_uV;
+	unsigned init_apply:1;
+};
+
+#endif /* __REGULATOR_TPS6236X_H */