[PATCH 1/2] Add support for TPS6235x support

[Manikandan Pillai <mani.pillai@ti.com>]

The patch has been fixed for comments given by David Brownell
and Mark Brown for adding TPS6235x support on OMAP3 EVM.
Comments fixed include
moving Makefile changes to this patch
dev_err used
removed the extra configuration option from Kconfig

Signed-off-by: Manikandan Pillai <mani.pillai@ti.com>
---
 drivers/regulator/Kconfig              |    8 +
 drivers/regulator/Makefile             |    1 +
 drivers/regulator/tps6235x-regulator.c |  350 ++++++++++++++++++++++++++++++++
 3 files changed, 359 insertions(+), 0 deletions(-)
 create mode 100644 drivers/regulator/tps6235x-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 0765389..c61024f 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -80,4 +80,12 @@ config REGULATOR_DA903X
 	  Say y here to support the BUCKs and LDOs regulators found on
 	  Dialog Semiconductor DA9030/DA9034 PMIC.
 
+config REGULATOR_TPS6235X
+        tristate "TI TPS6235x Power regulators"
+	depends on I2C
+	help
+          This driver supports TPS6235x voltage regulator chips, for values
+	  of "x" from 0 to 6.  These are buck converters which support TI's
+	  hardware based "SmartReflex" dynamic voltage scaling.
+
 endif
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 0dacb18..fdc5f5b 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -12,5 +12,6 @@ obj-$(CONFIG_REGULATOR_TWL4030) += twl4030-regulator.o
 obj-$(CONFIG_REGULATOR_WM8350) += wm8350-regulator.o
 obj-$(CONFIG_REGULATOR_WM8400) += wm8400-regulator.o
 obj-$(CONFIG_REGULATOR_DA903X)	+= da903x.o
+obj-$(CONFIG_REGULATOR_TPS6235X)+= tps6235x-regulator.o
 
 ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG
diff --git a/drivers/regulator/tps6235x-regulator.c b/drivers/regulator/tps6235x-regulator.c
new file mode 100644
index 0000000..f10fae6
--- /dev/null
+++ b/drivers/regulator/tps6235x-regulator.c
@@ -0,0 +1,350 @@
+/*
+ * tps6235x-regulator.c -- support regulators in tps6235x family chips
+ *
+ * Author : Manikandan Pillai<mani.pillai@ti.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/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/i2c.h>
+#include <linux/delay.h>
+
+/*
+ * These chips are often used in OMAP-based systems.
+ *
+ * This driver implements software-based resource control for various
+ * voltage regulators.  This is usually augmented with state machine
+ * based control.
+ *
+ * For now, all regulator operations apply to VSEL1 (the "ceiling"),
+ * instead of VSEL0 (the "floor") which is used for low power modes.
+ * Also, this *assumes* only software mode control is used...
+*/
+
+#define	TPS6235X_REG_VSEL0	0
+#define	TPS6235X_REG_VSEL1	1
+#define	TPS6235X_REG_CTRL1	2
+#define	TPS6235X_REG_CTRL2	3
+
+/* VSEL bitfields (EN_DCDC is shared) */
+#define	TPS6235X_EN_DCDC	BIT(7)
+#define	TPS6235X_LIGHTPFM	BIT(6)
+#define	TPS6235X_VSM_MSK	(0x3F)
+
+/* CTRL1 bitfields */
+#define TPS6235X_EN_SYNC	BIT(5)
+#define TPS6235X_HW_nSW		BIT(4)
+
+/* CTRL2 bitfields */
+#define TPS6235X_PWR_OK_MSK	BIT(5)
+#define TPS6235X_OUT_DIS_MSK	BIT(6)
+#define TPS6235X_GO_MSK		BIT(7)
+
+struct tps_info {
+	unsigned		min_uV;
+	unsigned		max_uV;
+	unsigned		mult_uV;
+	bool			fixed;
+};
+
+struct tps {
+	struct regulator_desc	desc;
+	struct i2c_client	*client;
+	struct regulator_dev	*rdev;
+	const struct tps_info	*info;
+};
+
+static inline int tps_6235x_read_reg(struct tps *tps, u8 reg, u8 *val)
+{
+	int status;
+
+	status = i2c_smbus_read_byte_data(tps->client, reg);
+	*val = status;
+	if (status < 0)
+		return status;
+	return 0;
+}
+
+static inline int tps_6235x_write_reg(struct tps *tps, u8 reg, u8 val)
+{
+	return i2c_smbus_write_byte_data(tps->client, reg, val);
+}
+
+static int tps6235x_dcdc_is_enabled(struct regulator_dev *dev)
+{
+	struct tps *tps = rdev_get_drvdata(dev);
+
+	ret = tps_6235x_read_reg(tps, TPS6235X_REG_VSEL1, &vsel1);
+	/* REVISIT we need to be able to report errors here ... */
+
+	return !!(vsel1 & TPS6235X_EN_DCDC);
+}
+
+static int tps6235x_dcdc_enable(struct regulator_dev *dev)
+{
+	unsigned char vsel1;
+	int ret;
+	struct tps *tps = rdev_get_drvdata(dev);
+
+	ret = tps_6235x_read_reg(tps, TPS6235X_REG_VSEL1, &vsel1);
+
+	if (ret == 0) {
+		vsel1 |= TPS6235X_EN_DCDC;
+		ret = tps_6235x_write_reg(tps, TPS6235X_REG_VSEL1, vsel1);
+	}
+	return ret;
+}
+
+static int tps6235x_dcdc_disable(struct regulator_dev *dev)
+{
+	unsigned char vsel1;
+	int ret;
+	struct tps *tps = rdev_get_drvdata(dev);
+
+	ret = tps_6235x_read_reg(tps, TPS6235X_REG_VSEL1, &vsel1);
+	if (ret == 0) {
+		vsel1 &= ~(TPS6235X_EN_DCDC);
+		ret = tps_6235x_write_reg(tps, TPS6235X_REG_VSEL1, vsel1);
+	}
+	return ret;
+}
+
+static int tps6235x_dcdc_get_voltage(struct regulator_dev *dev)
+{
+	struct i2c_client *tps_info = rdev_get_drvdata(dev);
+	unsigned char vsel1;
+	const struct tps_info *info = tps->info;
+	int status;
+
+	status = tps_6235x_read_reg(tps, TPS6235X_REG_VSEL1, &vsel1);
+	if (status < 0)
+		return status;
+	return info->min_uV + ((vsel1 & TPS6235X_VSM_MSK) * info->mult_uV);
+}
+
+static int tps6235x_dcdc_set_voltage(struct regulator_dev *dev,
+				int min_uV, int max_uV)
+{
+	struct tps *tps = rdev_get_drvdata(dev);
+	const struct tps_info *info = tps->info;
+	unsigned char vsel1;
+	unsigned step;
+	int status;
+
+	/* Output voltage set is = min_op_volt + ( VSM * 12.5mv) */
+	/* compute and sanity-check voltage step multiplier */
+	step = DIV_ROUND_UP(min_uV - info->min_uV, info->mult_uV);
+	if ((info->min_uV + (step * info->mult_uV)) > max_uV)
+		return -EINVAL;
+
+	status = tps_6235x_read_reg(tps, TPS6235X_REG_VSEL1, &vsel1);
+	if (status < 0)
+		return status;
+
+	/* update voltage */
+	vsel1 &= ~TPS6235X_VSM_MSK;
+	vsel1 |= step;
+	return tps_6235x_write_reg(tps, TPS6235X_REG_VSEL1, vsel1);
+}
+
+/* tps6345{0,2,4,5} have some parameters hard-wired */
+static struct regulator_ops tps6235x_fixed_dcdc_ops = {
+	.is_enabled	= tps6235x_dcdc_is_enabled,
+	.get_voltage	= tps6235x_dcdc_get_voltage,
+	.set_voltage	= tps6235x_dcdc_set_voltage,
+};
+
+/* tps6345{1,3,6} are more programmable */
+static struct regulator_ops tps6235x_dcdc_ops = {
+	.is_enabled	= tps6235x_dcdc_is_enabled,
+	.enable		= tps6235x_dcdc_enable,
+	.disable	= tps6235x_dcdc_disable,
+	.get_voltage	= tps6235x_dcdc_get_voltage,
+	.set_voltage	= tps6235x_dcdc_set_voltage,
+
+};
+
+static
+int tps_6235x_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+	static int desc_id;
+	const struct tps_info *info = (void *)id->driver_data;
+	struct regulator_init_data *init_data;
+	struct regulator_dev *rdev;
+	struct tps *tps;
+
+	unsigned char reg_val;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -EIO;
+
+	init_data = client->dev.platform_data;
+	if (!init_data)
+		return -EIO;
+
+	tps = kzalloc(sizeof(*tps), GFP_KERNEL);
+	if (!tps)
+		return -ENOMEM;
+
+	tps->desc.name = id->name;
+	tps->desc.id = desc_id++;
+	tps->desc.ops = info->fixed ? &tps6235x_fixed_dcdc_ops :
+			&tps6235x_dcdc_ops;
+	tps->desc.type = REGULATOR_VOLTAGE;
+	tps->desc.owner = THIS_MODULE;
+
+	tps->client = client;
+	tps->info = info;
+
+	/* FIXME board init code should provide init_data->driver_data
+	 * saying how to configure this regulator:  how big is the
+	 * inductor (affects light PFM mode optimization), slew rate,
+	 * PLL multiplier, and so forth.
+	 */
+	tps_6235x_read_reg(tps, TPS6235X_REG_CTRL2, &reg_val);
+
+	reg_val |= (TPS6235X_OUT_DIS_MSK | TPS6235X_GO_MSK);
+
+	tps_6235x_write_reg(tps, TPS6235X_REG_CTRL2, reg_val);
+	tps_6235x_read_reg(tps, TPS6235X_REG_CTRL2, &reg_val);
+
+	if (reg_val & TPS6235X_PWR_OK_MSK)
+		dev_dbg(&client->dev, "Power is OK  %x\n", reg_val);
+	else
+		dev_err(&client->dev, "Power not in range \n");
+
+	/* Register the regulators */
+	rdev = regulator_register(&tps->desc, &client->dev, tps);
+
+	if (IS_ERR(rdev)) {
+		dev_err(&client->dev, "failed to register %s\n", id->name);
+			kfree(tps);
+
+		return PTR_ERR(rdev);
+	}
+
+	/* Save regulator for cleanup */
+	tps->rdev = rdev;
+	i2c_set_clientdata(client, tps);
+
+	return 0;
+}
+
+/**
+ * tps_6235x_remove - TPS6235x driver i2c remove handler
+ * @client: i2c driver client device structure
+ *
+ * Unregister  TPS driver as an i2c client device driver
+ */
+static int __devexit tps_6235x_remove(struct i2c_client *client)
+{
+	struct tps *tps = i2c_get_clientdata(client);
+	regulator_unregister(tps->rdev);
+	/* clear the client data in i2c */
+	i2c_set_clientdata(client, NULL);
+	kfree(tps);
+	return 0;
+}
+
+/*
+ * These regulators have the same register structure, and differ
+ * primarily according to supported voltages and default settings.
+ */
+static const struct tps_info tps62350_info = {
+	.min_uV		=  750000,
+	.max_uV		= 1537500,
+	.mult_uV	=   12500,
+	.fixed		=	1,
+};
+static const struct tps_info tps62351_info = {
+	.min_uV		=  900000,
+	.max_uV		= 1687500,
+	.mult_uV	=   12500,
+};
+static const struct tps_info tps62352_info = {
+	.min_uV		=  750000,
+	.max_uV		= 1437500,
+	.mult_uV	=   12500,
+	.fixed		=	1,
+};
+static const struct tps_info tps62353_info = {
+	.min_uV		=  750000,
+	.max_uV		= 1537500,
+	.mult_uV	=   12500,
+};
+static const struct tps_info tps62354_info = {
+	.min_uV		=  750000,
+	.max_uV		= 1537500,
+	.mult_uV	=   12500,
+	.fixed		=	1,
+};
+static const struct tps_info tps62355_info = {
+	.min_uV		=  750000,
+	.max_uV		= 1537500,
+	.mult_uV	=   12500,
+	.fixed		=	1,
+};
+static const struct tps_info tps62356_info = {
+	.min_uV		= 1500000,
+	.max_uV		= 1975000,
+	.mult_uV	=   25000,
+};
+
+static const struct i2c_device_id tps_6235x_id[] = {
+	{ "tps62350", (unsigned long) &tps62350_info, },
+	{ "tps62351", (unsigned long) &tps62351_info, },
+	{ "tps62352", (unsigned long) &tps62352_info, },
+	{ "tps62353", (unsigned long) &tps62353_info, },
+	{ "tps62354", (unsigned long) &tps62354_info, },
+	{ "tps62355", (unsigned long) &tps62355_info, },
+	{ "tps62356", (unsigned long) &tps62356_info, },
+	{},
+};
+
+MODULE_DEVICE_TABLE(i2c, tps_6235x_id);
+
+static struct i2c_driver tps_6235x_i2c_driver = {
+	.driver = {
+		.name	=	"tps_6235x_pwr",
+		.owner	=	THIS_MODULE,
+	},
+	.probe		= tps_6235x_probe,
+	.remove		= __devexit_p(tps_6235x_remove),
+	.id_table	= tps_6235x_id,
+};
+
+/**
+ * tps_6235x_init
+ *
+ * Module init function
+ */
+static int __init tps_6235x_init(void)
+{
+	return i2c_add_driver(&tps_6235x_i2c_driver);
+}
+subsys_initcall(tps_6235x_init);
+
+/**
+ * tps_6235x_cleanup
+ *
+ * Module exit function
+ */
+static void __exit tps_6235x_cleanup(void)
+{
+	i2c_del_driver(&tps_6235x_i2c_driver);
+}
+module_exit(tps_6235x_cleanup);
+
+MODULE_AUTHOR("Texas Instruments");
+MODULE_DESCRIPTION("TPS6235x voltage regulator driver");
+MODULE_LICENSE("GPL");
-- 
1.5.6