drivers/regulator/anatop-regulator.c - kernel/common - Git at Google

 /*
  * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
  */

 /*
  * 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.
  */

 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/mfd/syscon.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/machine.h>

 #define LDO_RAMP_UP_UNIT_IN_CYCLES      64 /* 64 cycles per step */
 #define LDO_RAMP_UP_FREQ_IN_MHZ         24 /* cycle based on 24M OSC */

 #define LDO_POWER_GATE			0x00
 #define LDO_FET_FULL_ON			0x1f

 struct anatop_regulator {
 	u32 control_reg;
 	struct regmap *anatop;
 	int vol_bit_shift;
 	int vol_bit_width;
 	u32 delay_reg;
 	int delay_bit_shift;
 	int delay_bit_width;
 	int min_bit_val;
 	int min_voltage;
 	int max_voltage;
 	struct regulator_desc rdesc;
 	struct regulator_init_data *initdata;
 	bool bypass;
 	int sel;
 };

 static int anatop_regmap_set_voltage_time_sel(struct regulator_dev *reg,
 	unsigned int old_sel,
 	unsigned int new_sel)
 {
 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 	u32 val;
 	int ret = 0;

 	/* check whether need to care about LDO ramp up speed */
 	if (anatop_reg->delay_bit_width && new_sel > old_sel) {
 		/*
 		 * the delay for LDO ramp up time is
 		 * based on the register setting, we need
 		 * to calculate how many steps LDO need to
 		 * ramp up, and how much delay needed. (us)
 		 */
 		regmap_read(anatop_reg->anatop, anatop_reg->delay_reg, &val);
 		val = (val >> anatop_reg->delay_bit_shift) &
 			((1 << anatop_reg->delay_bit_width) - 1);
 		ret = (new_sel - old_sel) * (LDO_RAMP_UP_UNIT_IN_CYCLES <<
 			val) / LDO_RAMP_UP_FREQ_IN_MHZ + 1;
 	}

 	return ret;
 }

 static int anatop_regmap_enable(struct regulator_dev *reg)
 {
 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 	int sel;

 	sel = anatop_reg->bypass ? LDO_FET_FULL_ON : anatop_reg->sel;
 	return regulator_set_voltage_sel_regmap(reg, sel);
 }

 static int anatop_regmap_disable(struct regulator_dev *reg)
 {
 	return regulator_set_voltage_sel_regmap(reg, LDO_POWER_GATE);
 }

 static int anatop_regmap_is_enabled(struct regulator_dev *reg)
 {
 	return regulator_get_voltage_sel_regmap(reg) != LDO_POWER_GATE;
 }

 static int anatop_regmap_core_set_voltage_sel(struct regulator_dev *reg,
 					      unsigned selector)
 {
 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 	int ret;

 	if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg)) {
 		anatop_reg->sel = selector;
 		return 0;
 	}

 	ret = regulator_set_voltage_sel_regmap(reg, selector);
 	if (!ret)
 		anatop_reg->sel = selector;
 	return ret;
 }

 static int anatop_regmap_core_get_voltage_sel(struct regulator_dev *reg)
 {
 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);

 	if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg))
 		return anatop_reg->sel;

 	return regulator_get_voltage_sel_regmap(reg);
 }

 static int anatop_regmap_get_bypass(struct regulator_dev *reg, bool *enable)
 {
 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 	int sel;

 	sel = regulator_get_voltage_sel_regmap(reg);
 	if (sel == LDO_FET_FULL_ON)
 		WARN_ON(!anatop_reg->bypass);
 	else if (sel != LDO_POWER_GATE)
 		WARN_ON(anatop_reg->bypass);

 	*enable = anatop_reg->bypass;
 	return 0;
 }

 static int anatop_regmap_set_bypass(struct regulator_dev *reg, bool enable)
 {
 	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 	int sel;

 	if (enable == anatop_reg->bypass)
 		return 0;

 	sel = enable ? LDO_FET_FULL_ON : anatop_reg->sel;
 	anatop_reg->bypass = enable;

 	return regulator_set_voltage_sel_regmap(reg, sel);
 }

 static struct regulator_ops anatop_rops = {
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.list_voltage = regulator_list_voltage_linear,
 	.map_voltage = regulator_map_voltage_linear,
 };

 static struct regulator_ops anatop_core_rops = {
 	.enable = anatop_regmap_enable,
 	.disable = anatop_regmap_disable,
 	.is_enabled = anatop_regmap_is_enabled,
 	.set_voltage_sel = anatop_regmap_core_set_voltage_sel,
 	.set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
 	.get_voltage_sel = anatop_regmap_core_get_voltage_sel,
 	.list_voltage = regulator_list_voltage_linear,
 	.map_voltage = regulator_map_voltage_linear,
 	.get_bypass = anatop_regmap_get_bypass,
 	.set_bypass = anatop_regmap_set_bypass,
 };

 static int anatop_regulator_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct device_node *anatop_np;
 	struct regulator_desc *rdesc;
 	struct regulator_dev *rdev;
 	struct anatop_regulator *sreg;
 	struct regulator_init_data *initdata;
 	struct regulator_config config = { };
 	int ret = 0;
 	u32 val;

 	sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
 	if (!sreg)
 		return -ENOMEM;

 	rdesc = &sreg->rdesc;
 	rdesc->type = REGULATOR_VOLTAGE;
 	rdesc->owner = THIS_MODULE;

 	of_property_read_string(np, "regulator-name", &rdesc->name);
 	if (!rdesc->name) {
 		dev_err(dev, "failed to get a regulator-name\n");
 		return -EINVAL;
 	}

 	initdata = of_get_regulator_init_data(dev, np, rdesc);
 	if (!initdata)
 		return -ENOMEM;

 	initdata->supply_regulator = "vin";
 	sreg->initdata = initdata;

 	anatop_np = of_get_parent(np);
 	if (!anatop_np)
 		return -ENODEV;
 	sreg->anatop = syscon_node_to_regmap(anatop_np);
 	of_node_put(anatop_np);
 	if (IS_ERR(sreg->anatop))
 		return PTR_ERR(sreg->anatop);

 	ret = of_property_read_u32(np, "anatop-reg-offset",
 				   &sreg->control_reg);
 	if (ret) {
 		dev_err(dev, "no anatop-reg-offset property set\n");
 		return ret;
 	}
 	ret = of_property_read_u32(np, "anatop-vol-bit-width",
 				   &sreg->vol_bit_width);
 	if (ret) {
 		dev_err(dev, "no anatop-vol-bit-width property set\n");
 		return ret;
 	}
 	ret = of_property_read_u32(np, "anatop-vol-bit-shift",
 				   &sreg->vol_bit_shift);
 	if (ret) {
 		dev_err(dev, "no anatop-vol-bit-shift property set\n");
 		return ret;
 	}
 	ret = of_property_read_u32(np, "anatop-min-bit-val",
 				   &sreg->min_bit_val);
 	if (ret) {
 		dev_err(dev, "no anatop-min-bit-val property set\n");
 		return ret;
 	}
 	ret = of_property_read_u32(np, "anatop-min-voltage",
 				   &sreg->min_voltage);
 	if (ret) {
 		dev_err(dev, "no anatop-min-voltage property set\n");
 		return ret;
 	}
 	ret = of_property_read_u32(np, "anatop-max-voltage",
 				   &sreg->max_voltage);
 	if (ret) {
 		dev_err(dev, "no anatop-max-voltage property set\n");
 		return ret;
 	}

 	/* read LDO ramp up setting, only for core reg */
 	of_property_read_u32(np, "anatop-delay-reg-offset",
 			     &sreg->delay_reg);
 	of_property_read_u32(np, "anatop-delay-bit-width",
 			     &sreg->delay_bit_width);
 	of_property_read_u32(np, "anatop-delay-bit-shift",
 			     &sreg->delay_bit_shift);

 	rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage) / 25000 + 1
 			    + sreg->min_bit_val;
 	rdesc->min_uV = sreg->min_voltage;
 	rdesc->uV_step = 25000;
 	rdesc->linear_min_sel = sreg->min_bit_val;
 	rdesc->vsel_reg = sreg->control_reg;
 	rdesc->vsel_mask = ((1 << sreg->vol_bit_width) - 1) <<
 			   sreg->vol_bit_shift;
 	rdesc->min_dropout_uV = 125000;

 	config.dev = &pdev->dev;
 	config.init_data = initdata;
 	config.driver_data = sreg;
 	config.of_node = pdev->dev.of_node;
 	config.regmap = sreg->anatop;

 	/* Only core regulators have the ramp up delay configuration. */
 	if (sreg->control_reg && sreg->delay_bit_width) {
 		rdesc->ops = &anatop_core_rops;

 		ret = regmap_read(config.regmap, rdesc->vsel_reg, &val);
 		if (ret) {
 			dev_err(dev, "failed to read initial state\n");
 			return ret;
 		}

 		sreg->sel = (val & rdesc->vsel_mask) >> sreg->vol_bit_shift;
 		if (sreg->sel == LDO_FET_FULL_ON) {
 			sreg->sel = 0;
 			sreg->bypass = true;
 		}

 		/*
 		 * In case vddpu was disabled by the bootloader, we need to set
 		 * a sane default until imx6-cpufreq was probed and changes the
 		 * voltage to the correct value. In this case we set 1.25V.
 		 */
 		if (!sreg->sel && !strcmp(rdesc->name, "vddpu"))
 			sreg->sel = 22;

 		/* set the default voltage of the pcie phy to be 1.100v */
 		if (!sreg->sel && !strcmp(rdesc->name, "vddpcie"))
 			sreg->sel = 0x10;

 		if (!sreg->bypass && !sreg->sel) {
 			dev_err(&pdev->dev, "Failed to read a valid default voltage selector.\n");
 			return -EINVAL;
 		}
 	} else {
 		u32 enable_bit;

 		rdesc->ops = &anatop_rops;

 		if (!of_property_read_u32(np, "anatop-enable-bit",
 					  &enable_bit)) {
 			anatop_rops.enable  = regulator_enable_regmap;
 			anatop_rops.disable = regulator_disable_regmap;
 			anatop_rops.is_enabled = regulator_is_enabled_regmap;

 			rdesc->enable_reg = sreg->control_reg;
 			rdesc->enable_mask = BIT(enable_bit);
 		}
 	}

 	/* register regulator */
 	rdev = devm_regulator_register(dev, rdesc, &config);
 	if (IS_ERR(rdev)) {
 		dev_err(dev, "failed to register %s\n",
 			rdesc->name);
 		return PTR_ERR(rdev);
 	}

 	platform_set_drvdata(pdev, rdev);

 	return 0;
 }

 static const struct of_device_id of_anatop_regulator_match_tbl[] = {
 	{ .compatible = "fsl,anatop-regulator", },
 	{ /* end */ }
 };
 MODULE_DEVICE_TABLE(of, of_anatop_regulator_match_tbl);

 static struct platform_driver anatop_regulator_driver = {
 	.driver = {
 		.name	= "anatop_regulator",
 		.of_match_table = of_anatop_regulator_match_tbl,
 	},
 	.probe	= anatop_regulator_probe,
 };

 static int __init anatop_regulator_init(void)
 {
 	return platform_driver_register(&anatop_regulator_driver);
 }
 postcore_initcall(anatop_regulator_init);

 static void __exit anatop_regulator_exit(void)
 {
 	platform_driver_unregister(&anatop_regulator_driver);
 }
 module_exit(anatop_regulator_exit);

 MODULE_AUTHOR("Nancy Chen <[email protected]>");
 MODULE_AUTHOR("Ying-Chun Liu (PaulLiu) <[email protected]>");
 MODULE_DESCRIPTION("ANATOP Regulator driver");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:anatop_regulator");
	/*
	* Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
	*/

	/*
	* 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.
	*/

	#include <linux/slab.h>
	#include <linux/device.h>
	#include <linux/module.h>
	#include <linux/mfd/syscon.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/platform_device.h>
	#include <linux/of.h>
	#include <linux/of_address.h>
	#include <linux/regmap.h>
	#include <linux/regulator/driver.h>
	#include <linux/regulator/of_regulator.h>
	#include <linux/regulator/machine.h>

	#define LDO_RAMP_UP_UNIT_IN_CYCLES 64 /* 64 cycles per step */
	#define LDO_RAMP_UP_FREQ_IN_MHZ 24 /* cycle based on 24M OSC */

	#define LDO_POWER_GATE 0x00
	#define LDO_FET_FULL_ON 0x1f

	struct anatop_regulator {
	u32 control_reg;
	struct regmap *anatop;
	int vol_bit_shift;
	int vol_bit_width;
	u32 delay_reg;
	int delay_bit_shift;
	int delay_bit_width;
	int min_bit_val;
	int min_voltage;
	int max_voltage;
	struct regulator_desc rdesc;
	struct regulator_init_data *initdata;
	bool bypass;
	int sel;
	};

	static int anatop_regmap_set_voltage_time_sel(struct regulator_dev *reg,
	unsigned int old_sel,
	unsigned int new_sel)
	{
	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
	u32 val;
	int ret = 0;

	/* check whether need to care about LDO ramp up speed */
	if (anatop_reg->delay_bit_width && new_sel > old_sel) {
	/*
	* the delay for LDO ramp up time is
	* based on the register setting, we need
	* to calculate how many steps LDO need to
	* ramp up, and how much delay needed. (us)
	*/
	regmap_read(anatop_reg->anatop, anatop_reg->delay_reg, &val);
	val = (val >> anatop_reg->delay_bit_shift) &
	((1 << anatop_reg->delay_bit_width) - 1);
	ret = (new_sel - old_sel) * (LDO_RAMP_UP_UNIT_IN_CYCLES <<
	val) / LDO_RAMP_UP_FREQ_IN_MHZ + 1;
	}

	return ret;
	}

	static int anatop_regmap_enable(struct regulator_dev *reg)
	{
	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
	int sel;

	sel = anatop_reg->bypass ? LDO_FET_FULL_ON : anatop_reg->sel;
	return regulator_set_voltage_sel_regmap(reg, sel);
	}

	static int anatop_regmap_disable(struct regulator_dev *reg)
	{
	return regulator_set_voltage_sel_regmap(reg, LDO_POWER_GATE);
	}

	static int anatop_regmap_is_enabled(struct regulator_dev *reg)
	{
	return regulator_get_voltage_sel_regmap(reg) != LDO_POWER_GATE;
	}

	static int anatop_regmap_core_set_voltage_sel(struct regulator_dev *reg,
	unsigned selector)
	{
	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
	int ret;

	if (anatop_reg->bypass \|\| !anatop_regmap_is_enabled(reg)) {
	anatop_reg->sel = selector;
	return 0;
	}

	ret = regulator_set_voltage_sel_regmap(reg, selector);
	if (!ret)
	anatop_reg->sel = selector;
	return ret;
	}

	static int anatop_regmap_core_get_voltage_sel(struct regulator_dev *reg)
	{
	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);

	if (anatop_reg->bypass \|\| !anatop_regmap_is_enabled(reg))
	return anatop_reg->sel;

	return regulator_get_voltage_sel_regmap(reg);
	}

	static int anatop_regmap_get_bypass(struct regulator_dev reg, bool enable)
	{
	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
	int sel;

	sel = regulator_get_voltage_sel_regmap(reg);
	if (sel == LDO_FET_FULL_ON)
	WARN_ON(!anatop_reg->bypass);
	else if (sel != LDO_POWER_GATE)
	WARN_ON(anatop_reg->bypass);

	*enable = anatop_reg->bypass;
	return 0;
	}

	static int anatop_regmap_set_bypass(struct regulator_dev *reg, bool enable)
	{
	struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
	int sel;

	if (enable == anatop_reg->bypass)
	return 0;

	sel = enable ? LDO_FET_FULL_ON : anatop_reg->sel;
	anatop_reg->bypass = enable;

	return regulator_set_voltage_sel_regmap(reg, sel);
	}

	static struct regulator_ops anatop_rops = {
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.list_voltage = regulator_list_voltage_linear,
	.map_voltage = regulator_map_voltage_linear,
	};

	static struct regulator_ops anatop_core_rops = {
	.enable = anatop_regmap_enable,
	.disable = anatop_regmap_disable,
	.is_enabled = anatop_regmap_is_enabled,
	.set_voltage_sel = anatop_regmap_core_set_voltage_sel,
	.set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
	.get_voltage_sel = anatop_regmap_core_get_voltage_sel,
	.list_voltage = regulator_list_voltage_linear,
	.map_voltage = regulator_map_voltage_linear,
	.get_bypass = anatop_regmap_get_bypass,
	.set_bypass = anatop_regmap_set_bypass,
	};

	static int anatop_regulator_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct device_node *anatop_np;
	struct regulator_desc *rdesc;
	struct regulator_dev *rdev;
	struct anatop_regulator *sreg;
	struct regulator_init_data *initdata;
	struct regulator_config config = { };
	int ret = 0;
	u32 val;

	sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
	if (!sreg)
	return -ENOMEM;

	rdesc = &sreg->rdesc;
	rdesc->type = REGULATOR_VOLTAGE;
	rdesc->owner = THIS_MODULE;

	of_property_read_string(np, "regulator-name", &rdesc->name);
	if (!rdesc->name) {
	dev_err(dev, "failed to get a regulator-name\n");
	return -EINVAL;
	}

	initdata = of_get_regulator_init_data(dev, np, rdesc);
	if (!initdata)
	return -ENOMEM;

	initdata->supply_regulator = "vin";
	sreg->initdata = initdata;

	anatop_np = of_get_parent(np);
	if (!anatop_np)
	return -ENODEV;
	sreg->anatop = syscon_node_to_regmap(anatop_np);
	of_node_put(anatop_np);
	if (IS_ERR(sreg->anatop))
	return PTR_ERR(sreg->anatop);

	ret = of_property_read_u32(np, "anatop-reg-offset",
	&sreg->control_reg);
	if (ret) {
	dev_err(dev, "no anatop-reg-offset property set\n");
	return ret;
	}
	ret = of_property_read_u32(np, "anatop-vol-bit-width",
	&sreg->vol_bit_width);
	if (ret) {
	dev_err(dev, "no anatop-vol-bit-width property set\n");
	return ret;
	}
	ret = of_property_read_u32(np, "anatop-vol-bit-shift",
	&sreg->vol_bit_shift);
	if (ret) {
	dev_err(dev, "no anatop-vol-bit-shift property set\n");
	return ret;
	}
	ret = of_property_read_u32(np, "anatop-min-bit-val",
	&sreg->min_bit_val);
	if (ret) {
	dev_err(dev, "no anatop-min-bit-val property set\n");
	return ret;
	}
	ret = of_property_read_u32(np, "anatop-min-voltage",
	&sreg->min_voltage);
	if (ret) {
	dev_err(dev, "no anatop-min-voltage property set\n");
	return ret;
	}
	ret = of_property_read_u32(np, "anatop-max-voltage",
	&sreg->max_voltage);
	if (ret) {
	dev_err(dev, "no anatop-max-voltage property set\n");
	return ret;
	}

	/* read LDO ramp up setting, only for core reg */
	of_property_read_u32(np, "anatop-delay-reg-offset",
	&sreg->delay_reg);
	of_property_read_u32(np, "anatop-delay-bit-width",
	&sreg->delay_bit_width);
	of_property_read_u32(np, "anatop-delay-bit-shift",
	&sreg->delay_bit_shift);

	rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage) / 25000 + 1
	+ sreg->min_bit_val;
	rdesc->min_uV = sreg->min_voltage;
	rdesc->uV_step = 25000;
	rdesc->linear_min_sel = sreg->min_bit_val;
	rdesc->vsel_reg = sreg->control_reg;
	rdesc->vsel_mask = ((1 << sreg->vol_bit_width) - 1) <<
	sreg->vol_bit_shift;
	rdesc->min_dropout_uV = 125000;

	config.dev = &pdev->dev;
	config.init_data = initdata;
	config.driver_data = sreg;
	config.of_node = pdev->dev.of_node;
	config.regmap = sreg->anatop;

	/* Only core regulators have the ramp up delay configuration. */
	if (sreg->control_reg && sreg->delay_bit_width) {
	rdesc->ops = &anatop_core_rops;

	ret = regmap_read(config.regmap, rdesc->vsel_reg, &val);
	if (ret) {
	dev_err(dev, "failed to read initial state\n");
	return ret;
	}

	sreg->sel = (val & rdesc->vsel_mask) >> sreg->vol_bit_shift;
	if (sreg->sel == LDO_FET_FULL_ON) {
	sreg->sel = 0;
	sreg->bypass = true;
	}

	/*
	* In case vddpu was disabled by the bootloader, we need to set
	* a sane default until imx6-cpufreq was probed and changes the
	* voltage to the correct value. In this case we set 1.25V.
	*/
	if (!sreg->sel && !strcmp(rdesc->name, "vddpu"))
	sreg->sel = 22;

	/* set the default voltage of the pcie phy to be 1.100v */
	if (!sreg->sel && !strcmp(rdesc->name, "vddpcie"))
	sreg->sel = 0x10;

	if (!sreg->bypass && !sreg->sel) {
	dev_err(&pdev->dev, "Failed to read a valid default voltage selector.\n");
	return -EINVAL;
	}
	} else {
	u32 enable_bit;

	rdesc->ops = &anatop_rops;

	if (!of_property_read_u32(np, "anatop-enable-bit",
	&enable_bit)) {
	anatop_rops.enable = regulator_enable_regmap;
	anatop_rops.disable = regulator_disable_regmap;
	anatop_rops.is_enabled = regulator_is_enabled_regmap;

	rdesc->enable_reg = sreg->control_reg;
	rdesc->enable_mask = BIT(enable_bit);
	}
	}

	/* register regulator */
	rdev = devm_regulator_register(dev, rdesc, &config);
	if (IS_ERR(rdev)) {
	dev_err(dev, "failed to register %s\n",
	rdesc->name);
	return PTR_ERR(rdev);
	}

	platform_set_drvdata(pdev, rdev);

	return 0;
	}

	static const struct of_device_id of_anatop_regulator_match_tbl[] = {
	{ .compatible = "fsl,anatop-regulator", },
	{ /* end */ }
	};
	MODULE_DEVICE_TABLE(of, of_anatop_regulator_match_tbl);

	static struct platform_driver anatop_regulator_driver = {
	.driver = {
	.name = "anatop_regulator",
	.of_match_table = of_anatop_regulator_match_tbl,
	},
	.probe = anatop_regulator_probe,
	};

	static int __init anatop_regulator_init(void)
	{
	return platform_driver_register(&anatop_regulator_driver);
	}
	postcore_initcall(anatop_regulator_init);

	static void __exit anatop_regulator_exit(void)
	{
	platform_driver_unregister(&anatop_regulator_driver);
	}
	module_exit(anatop_regulator_exit);

	MODULE_AUTHOR("Nancy Chen <[email protected]>");
	MODULE_AUTHOR("Ying-Chun Liu (PaulLiu) <[email protected]>");
	MODULE_DESCRIPTION("ANATOP Regulator driver");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:anatop_regulator");