regulator: add pbias regulator support

PBIAS internal regulator for SD card dual voltage i/o pads on OMAP SoCs.

Required properties:

- compatible:

  - "ti,pbias-omap" for OMAP2, OMAP3, OMAP4, OMAP5, DRA7.

- reg: pbias register offset from syscon base and size of pbias register.

- syscon : phandle of the system control module

- regulator-name : should be

			pbias_mmc_omap2430 for OMAP2430, OMAP3 SoCs

			pbias_sim_omap3 for OMAP3 SoCs

			pbias_mmc_omap4 for OMAP4 SoCs

			pbias_mmc_omap5 for OMAP5 and DRA7 SoC

Optional properties:

- Any optional property defined in bindings/regulator/regulator.txt

Example:

		pbias_regulator: pbias_regulator {

			compatible = "ti,pbias-omap";

			reg = <0 0x4>;

			syscon = <&omap5_padconf_global>;

			pbias_mmc_reg: pbias_mmc_omap5 {

				regulator-name = "pbias_mmc_omap5";

				regulator-min-microvolt = <1800000>;

				regulator-max-microvolt = <3000000>;

			};

	  on the muxing. This is handled automatically in the driver by

	  reading the mux info from OTP.

config REGULATOR_PBIAS

	tristate "PBIAS OMAP regulator driver"

	depends on (ARCH_OMAP || COMPILE_TEST) && MFD_SYSCON

	help

	 Say y here to support pbias regulator for mmc1:SD card i/o

	 on OMAP SoCs.

	 This driver provides support for OMAP pbias modelled

	 regulators.

config REGULATOR_PCAP

	tristate "Motorola PCAP2 regulator driver"

	depends on EZX_PCAP

obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o

obj-$(CONFIG_REGULATOR_PFUZE100) += pfuze100-regulator.o

obj-$(CONFIG_REGULATOR_TPS51632) += tps51632-regulator.o

obj-$(CONFIG_REGULATOR_PBIAS) += pbias-regulator.o

obj-$(CONFIG_REGULATOR_PCAP) += pcap-regulator.o

obj-$(CONFIG_REGULATOR_PCF50633) += pcf50633-regulator.o

obj-$(CONFIG_REGULATOR_RC5T583)  += rc5t583-regulator.o

/*

 * pbias-regulator.c

 *

 * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/

 * Author: Balaji T K <balajitk@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 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.

 */

#include <linux/err.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/mfd/syscon.h>

#include <linux/platform_device.h>

#include <linux/regulator/driver.h>

#include <linux/regulator/machine.h>

#include <linux/regulator/of_regulator.h>

#include <linux/regmap.h>

#include <linux/slab.h>

#include <linux/of.h>

#include <linux/of_device.h>

struct pbias_reg_info {

	u32 enable;

	u32 enable_mask;

	u32 vmode;

	unsigned int enable_time;

	char *name;

};

struct pbias_regulator_data {

	struct regulator_desc desc;

	void __iomem *pbias_addr;

	unsigned int pbias_reg;

	struct regulator_dev *dev;

	struct regmap *syscon;

	const struct pbias_reg_info *info;

	int voltage;

};

static int pbias_regulator_set_voltage(struct regulator_dev *dev,

			int min_uV, int max_uV, unsigned *selector)

{

	struct pbias_regulator_data *data = rdev_get_drvdata(dev);

	const struct pbias_reg_info *info = data->info;

	int ret, vmode;

	if (min_uV <= 1800000)

		vmode = 0;

	else if (min_uV > 1800000)

		vmode = info->vmode;

	ret = regmap_update_bits(data->syscon, data->pbias_reg,

						info->vmode, vmode);

	return ret;

}

static int pbias_regulator_get_voltage(struct regulator_dev *rdev)

{

	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);

	const struct pbias_reg_info *info = data->info;

	int value, voltage;

	regmap_read(data->syscon, data->pbias_reg, &value);

	value &= info->vmode;

	voltage = value ? 3000000 : 1800000;

	return voltage;

}

static int pbias_regulator_enable(struct regulator_dev *rdev)

{

	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);

	const struct pbias_reg_info *info = data->info;

	int ret;

	ret = regmap_update_bits(data->syscon, data->pbias_reg,

					info->enable_mask, info->enable);

	return ret;

}

static int pbias_regulator_disable(struct regulator_dev *rdev)

{

	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);

	const struct pbias_reg_info *info = data->info;

	int ret;

	ret = regmap_update_bits(data->syscon, data->pbias_reg,

						info->enable_mask, 0);

	return ret;

}

static int pbias_regulator_is_enable(struct regulator_dev *rdev)

{

	struct pbias_regulator_data *data = rdev_get_drvdata(rdev);

	const struct pbias_reg_info *info = data->info;

	int value;

	regmap_read(data->syscon, data->pbias_reg, &value);

	return (value & info->enable_mask) == info->enable_mask;

}

static struct regulator_ops pbias_regulator_voltage_ops = {

	.set_voltage	= pbias_regulator_set_voltage,

	.get_voltage	= pbias_regulator_get_voltage,

	.enable		= pbias_regulator_enable,

	.disable	= pbias_regulator_disable,

	.is_enabled	= pbias_regulator_is_enable,

};

static const struct pbias_reg_info pbias_mmc_omap2430 = {

	.enable = BIT(1),

	.enable_mask = BIT(1),

	.vmode = BIT(0),

	.enable_time = 100,

	.name = "pbias_mmc_omap2430"

};

static const struct pbias_reg_info pbias_sim_omap3 = {

	.enable = BIT(9),

	.enable_mask = BIT(9),

	.vmode = BIT(8),

	.enable_time = 100,

	.name = "pbias_sim_omap3"

};

static const struct pbias_reg_info pbias_mmc_omap4 = {

	.enable = BIT(26) | BIT(22),

	.enable_mask = BIT(26) | BIT(25) | BIT(22),

	.vmode = BIT(21),

	.enable_time = 100,

	.name = "pbias_mmc_omap4"

};

static const struct pbias_reg_info pbias_mmc_omap5 = {

	.enable = BIT(27) | BIT(26),

	.enable_mask = BIT(27) | BIT(25) | BIT(26),

	.vmode = BIT(21),

	.enable_time = 100,

	.name = "pbias_mmc_omap5"

};

static struct of_regulator_match pbias_matches[] = {

	{ .name = "pbias_mmc_omap2430", .driver_data = (void *)&pbias_mmc_omap2430},

	{ .name = "pbias_sim_omap3", .driver_data = (void *)&pbias_sim_omap3},

	{ .name = "pbias_mmc_omap4", .driver_data = (void *)&pbias_mmc_omap4},

	{ .name = "pbias_mmc_omap5", .driver_data = (void *)&pbias_mmc_omap5},

};

#define PBIAS_NUM_REGS	ARRAY_SIZE(pbias_matches)

static const struct of_device_id pbias_of_match[] = {

	{ .compatible = "ti,pbias-omap", },

	{},

};

MODULE_DEVICE_TABLE(of, pbias_of_match);

static int pbias_regulator_probe(struct platform_device *pdev)

{

	struct device_node *np = pdev->dev.of_node;

	struct pbias_regulator_data *drvdata;

	struct resource *res;

	struct regulator_config cfg = { };

	struct regmap *syscon;

	const struct pbias_reg_info *info;

	int ret = 0;

	int count, idx, data_idx = 0;

	count = of_regulator_match(&pdev->dev, np, pbias_matches,

						PBIAS_NUM_REGS);

	if (count < 0)

		return count;

	drvdata = devm_kzalloc(&pdev->dev, sizeof(struct pbias_regulator_data)

			       * count, GFP_KERNEL);

	if (drvdata == NULL) {

		dev_err(&pdev->dev, "Failed to allocate device data\n");

		return -ENOMEM;

	}

	syscon = syscon_regmap_lookup_by_phandle(np, "syscon");

	if (IS_ERR(syscon))

		return PTR_ERR(syscon);

	cfg.dev = &pdev->dev;

	for (idx = 0; idx < PBIAS_NUM_REGS && data_idx < count; idx++) {

		if (!pbias_matches[idx].init_data ||

			!pbias_matches[idx].of_node)

			continue;

		info = pbias_matches[idx].driver_data;

		if (!info)

			return -ENODEV;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

		if (!res)

			return -EINVAL;

		drvdata[data_idx].pbias_reg = res->start;

		drvdata[data_idx].syscon = syscon;

		drvdata[data_idx].info = info;

		drvdata[data_idx].desc.name = info->name;

		drvdata[data_idx].desc.owner = THIS_MODULE;

		drvdata[data_idx].desc.type = REGULATOR_VOLTAGE;

		drvdata[data_idx].desc.ops = &pbias_regulator_voltage_ops;

		drvdata[data_idx].desc.n_voltages = 2;

		drvdata[data_idx].desc.enable_time = info->enable_time;

		cfg.init_data = pbias_matches[idx].init_data;

		cfg.driver_data = &drvdata[data_idx];

		cfg.of_node = pbias_matches[idx].of_node;

		drvdata[data_idx].dev = devm_regulator_register(&pdev->dev,

					&drvdata[data_idx].desc, &cfg);

		if (IS_ERR(drvdata[data_idx].dev)) {

			ret = PTR_ERR(drvdata[data_idx].dev);

			dev_err(&pdev->dev,

				"Failed to register regulator: %d\n", ret);

			goto err_regulator;

		}

		data_idx++;

	}

	platform_set_drvdata(pdev, drvdata);

err_regulator:

	return ret;

}

static struct platform_driver pbias_regulator_driver = {

	.probe		= pbias_regulator_probe,

	.driver		= {

		.name		= "pbias-regulator",

		.owner		= THIS_MODULE,

		.of_match_table = of_match_ptr(pbias_of_match),

	},

};

module_platform_driver(pbias_regulator_driver);

MODULE_AUTHOR("Balaji T K <balajitk@ti.com>");

MODULE_DESCRIPTION("pbias voltage regulator");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:pbias-regulator");