regulator: fan53555: add support for device tree and option 13 feature

Fairchild Semiconductor FAN53555 regulator

The FAN53555 is a step-down switching voltage regulator that delivers a

digitally programmable output from an input voltage supply of 2.5 V to 5.5 V.

The output voltage is programmed through an I2C interface capable of operating

up to 3.4 MHz.

The fan53555 interface is via I2C bus.

Required Properties:

- compatible:			Must be "fairchild,fan53555-regulator".

- reg:				The device 8-bit I2C address.

- fairchild,backup-vsel:	Register ID of backup register.

				Supported values are 0 or 1.

				The voltage selection ID used while the system

				is active will be the other option not used

				during running.

- regulator-min-microvolt:	Minimum voltage in microvolts supported by this

				regulator.

- regulator-max-microvolt:	Maximum voltage in microvolts supported by this

				regulator.

- regulator-ramp-delay:		The slew rate of the regulator, in uV/us.

				Supported values are 64000, 32000, 16000,

				8000, 4000, 2000, 1000 and 500.

Optional Properties:

- fairchild,vsel-gpio:		Present: GPIO connects to the VSEL pin and set

				the output.

				Not Present: No GPIO is connected to vsel pin.

- fairchild,restore-reg:	Present: Restore vsel register from backup

				register.

				Not Present: No restore.

- fairchild,disable-suspend:	Present: Disable regulator suspend method.

				Not Present: Do not disable regulator suspend

				method.

Example:

	i2c_0 {

		fan53555-regulator@60 {

			compatible = "fairchild,fan53555-regulator";

			reg = <0x60>;

			fairchild,backup-vsel = <1>;

			regulator-min-microvolt = <1050000>;

			regulator-max-microvolt = <1350000>;

			regulator-ramp-delay = <8000>;

			fairchild,vsel-gpio = <&msmgpio 2 1>;

			fairchild,restore-reg;

			fairchild,disable-suspend;

		};

	};

#include <linux/module.h>

#include <linux/param.h>

#include <linux/err.h>

#include <linux/gpio.h>

#include <linux/platform_device.h>

#include <linux/regulator/driver.h>

#include <linux/regulator/machine.h>

#include <linux/regulator/of_regulator.h>

#include <linux/of.h>

#include <linux/of_gpio.h>

#include <linux/i2c.h>

#include <linux/slab.h>

#include <linux/regmap.h>

#define VSEL_BUCK_EN	(1 << 7)

#define VSEL_MODE		(1 << 6)

#define VSEL_NSEL_MASK	0x3F

#define VSEL_FULL_MASK	0xFF

/* Chip ID and Verison */

#define DIE_ID		0x0F	/* ID1 */

#define DIE_REV		0x0F	/* ID2 */

#define DIE_13_REV	0x0F	/* DIE Revsion ID of 13 option */

/* Control bit definitions */

#define CTL_OUTPUT_DISCHG	(1 << 7)

#define CTL_SLEW_MASK		(0x7 << 4)

	FAN53555_CHIP_ID_05,

};

static const int slew_rate_plan[] = {

	64000,

	32000,

	16000,

	8000,

	4000,

	2000,

	1000,

	500

};

struct fan53555_device_info {

	struct regmap *regmap;

	struct device *dev;

	unsigned int slew_rate;

	/* Sleep voltage cache */

	unsigned int sleep_vol_cache;

	bool disable_suspend;

};

static int fan53555_set_suspend_voltage(struct regulator_dev *rdev, int uV)

}

static struct regulator_ops fan53555_regulator_ops = {

	.set_voltage_time_sel = regulator_set_voltage_time_sel,

	.set_voltage_sel = regulator_set_voltage_sel_regmap,

	.get_voltage_sel = regulator_get_voltage_sel_regmap,

	.map_voltage = regulator_map_voltage_linear,

	.get_mode = fan53555_get_mode,

};

static struct regulator_ops fan53555_regulator_disable_suspend_ops = {

	.set_voltage_time_sel = regulator_set_voltage_time_sel,

	.set_voltage_sel = regulator_set_voltage_sel_regmap,

	.get_voltage_sel = regulator_get_voltage_sel_regmap,

	.map_voltage = regulator_map_voltage_linear,

	.list_voltage = regulator_list_voltage_linear,

	.enable = regulator_enable_regmap,

	.disable = regulator_disable_regmap,

	.is_enabled = regulator_is_enabled_regmap,

	.set_mode = fan53555_set_mode,

	.get_mode = fan53555_get_mode,

};

/* For 00,01,03,05 options:

 * VOUT = 0.60V + NSELx * 10mV, from 0.60 to 1.23V.

 * For 04 option:

 * VOUT = 0.603V + NSELx * 12.826mV, from 0.603 to 1.411V.

 * For 13 option:

 * 13 option, its DIE ID is 0x00 and DIE_REV is 0x0F.

 * VOUT = 0.80V + NSELx * 10mV, from 0.80 to 1.43V.

 * */

static int fan53555_device_setup(struct fan53555_device_info *di,

				struct fan53555_platform_data *pdata)

	/* Init voltage range and step */

	switch (di->chip_id) {

	case FAN53555_CHIP_ID_00:

		if (di->chip_rev == DIE_13_REV) {

			di->vsel_min = 800000;

			di->vsel_step = 10000;

			break;

		}

	case FAN53555_CHIP_ID_01:

	case FAN53555_CHIP_ID_03:

	case FAN53555_CHIP_ID_05:

	struct regulator_desc *rdesc = &di->desc;

	rdesc->name = "fan53555-reg";

	if (di->disable_suspend)

		rdesc->ops = &fan53555_regulator_disable_suspend_ops;

	else

		rdesc->ops = &fan53555_regulator_ops;

	rdesc->type = REGULATOR_VOLTAGE;

	rdesc->n_voltages = FAN53555_NVOLTAGES;

	.val_bits = 8,

};

static int fan53555_parse_backup_reg(struct i2c_client *client, u32 *sleep_sel)

{

	int rc = -EINVAL;

	rc = of_property_read_u32(client->dev.of_node, "fairchild,backup-vsel",

				sleep_sel);

	if (rc) {

		dev_err(&client->dev, "fairchild,backup-vsel property missing\n");

	} else {

		switch (*sleep_sel) {

		case FAN53555_VSEL_ID_0:

		case FAN53555_VSEL_ID_1:

			break;

		default:

			dev_err(&client->dev, "Invalid VSEL ID!\n");

			rc = -EINVAL;

		}

	}

	return rc;

}

static u32 fan53555_get_slew_rate_reg_value(struct i2c_client *client,

					u32 slew_rate)

{

	u32 index;

	for (index = 0; index < ARRAY_SIZE(slew_rate_plan); index++)

		if (slew_rate == slew_rate_plan[index])

			break;

	if (index == ARRAY_SIZE(slew_rate_plan)) {

		dev_err(&client->dev, "invalid slew rate.\n");

		index = FAN53555_SLEW_RATE_8MV;

	}

	return index;

}

static struct fan53555_platform_data *

	fan53555_get_of_platform_data(struct i2c_client *client)

{

	struct fan53555_platform_data *pdata = NULL;

	struct regulator_init_data *init_data;

	u32 sleep_sel;

	init_data = of_get_regulator_init_data(&client->dev,

			client->dev.of_node);

	if (!init_data) {

		dev_err(&client->dev, "regulator init data is missing\n");

		return pdata;

	}

	if (fan53555_parse_backup_reg(client, &sleep_sel))

		return pdata;

	pdata = devm_kzalloc(&client->dev,

			sizeof(struct fan53555_platform_data), GFP_KERNEL);

	if (!pdata) {

		dev_err(&client->dev,

			"fan53555_platform_data allocation failed.\n");

		return pdata;

	}

	init_data->constraints.input_uV = init_data->constraints.max_uV;

	init_data->constraints.valid_ops_mask |=

		REGULATOR_CHANGE_STATUS	| REGULATOR_CHANGE_VOLTAGE |

		REGULATOR_CHANGE_MODE;

	init_data->constraints.valid_modes_mask =

				REGULATOR_MODE_NORMAL |

				REGULATOR_MODE_FAST;

	init_data->constraints.initial_mode = REGULATOR_MODE_NORMAL;

	pdata->regulator = init_data;

	pdata->slew_rate = fan53555_get_slew_rate_reg_value(client,

				init_data->constraints.ramp_delay);

	pdata->sleep_vsel_id = sleep_sel;

	return pdata;

}

static int fan53555_restore_working_reg(struct device_node *node,

			struct fan53555_device_info *di)

{

	int ret;

	u32 val;

	/* Restore register from back up register */

	ret = regmap_read(di->regmap, di->sleep_reg, &val);

	if (ret < 0) {

		dev_err(di->dev,

			"Failed to get backup data from reg %d, ret = %d\n",

			di->sleep_reg, ret);

		return ret;

	}

	ret = regmap_update_bits(di->regmap,

		di->vol_reg, VSEL_FULL_MASK, val);

	if (ret < 0) {

		dev_err(di->dev,

			"Failed to update working reg %d, ret = %d\n",

			di->vol_reg, ret);

		return ret;

	}

	return ret;

}

static int fan53555_of_init(struct device_node *node,

			struct fan53555_device_info *di)

{

	int ret, gpio;

	enum of_gpio_flags flags;

	if (of_property_read_bool(node, "fairchild,restore-reg")) {

		ret = fan53555_restore_working_reg(node, di);

		if (ret)

			return ret;

	}

	if (of_find_property(node, "fairchild,vsel-gpio", NULL)) {

		gpio = of_get_named_gpio_flags(node, "fairchild,vsel-gpio", 0,

						&flags);

		if (!gpio_is_valid(gpio)) {

			if (gpio != -EPROBE_DEFER)

				dev_err(di->dev, "Could not get vsel, ret = %d\n",

					gpio);

			return gpio;

		}

		ret = devm_gpio_request(di->dev, gpio, "fan53555_vsel");

		if (ret) {

			dev_err(di->dev, "Failed to obtain gpio %d ret = %d\n",

				gpio, ret);

			return ret;

		}

		ret = gpio_direction_output(gpio, flags & OF_GPIO_ACTIVE_LOW ?

							0 : 1);

		if (ret) {

			dev_err(di->dev,

				"Failed to set GPIO %d to: %s, ret = %d",

				gpio, flags & OF_GPIO_ACTIVE_LOW ?

				"GPIO_LOW" : "GPIO_HIGH", ret);

			return ret;

		}

	}

	di->disable_suspend = of_property_read_bool(node,

				"fairchild,disable-suspend");

	return 0;

}

static int fan53555_regulator_probe(struct i2c_client *client,

				const struct i2c_device_id *id)

{

	unsigned int val;

	int ret;

	if (client->dev.of_node)

		pdata = fan53555_get_of_platform_data(client);

	else

		pdata = client->dev.platform_data;

	if (!pdata || !pdata->regulator) {

		dev_err(&client->dev, "Platform data not found!\n");

		return -ENODEV;

		dev_err(&client->dev, "Failed to setup device!\n");

		return ret;

	}

	/* Set up from device tree */

	if (client->dev.of_node) {

		ret = fan53555_of_init(client->dev.of_node, di);

		if (ret)

			return ret;

	}

	/* Register regulator */

	config.dev = di->dev;

	config.init_data = di->regulator;

	config.regmap = di->regmap;

	config.driver_data = di;

	config.of_node = client->dev.of_node;

	ret = fan53555_regulator_register(di, &config);

	if (ret < 0)

		dev_err(&client->dev, "Failed to register regulator!\n");

	return ret;

}

	return 0;

}

static struct of_device_id fan53555_match_table[] = {

	{ .compatible = "fairchild,fan53555-regulator",},

	{},

};

MODULE_DEVICE_TABLE(of, fan53555_match_table);

static const struct i2c_device_id fan53555_id[] = {

	{"fan53555", -1},

	{ },

static struct i2c_driver fan53555_regulator_driver = {

	.driver = {

		.name = "fan53555-regulator",

		.owner = THIS_MODULE,

		.of_match_table = fan53555_match_table,

	},

	.probe = fan53555_regulator_probe,

	.remove = fan53555_regulator_remove,

	.id_table = fan53555_id,

};

module_i2c_driver(fan53555_regulator_driver);

/**

 * fan53555_regulator_init() - initialized fan53555 regulator driver

 * This function registers the fan53555 regulator platform driver.

 *

 * Returns 0 on success or errno on failure.

 */

int __init fan53555_regulator_init(void)

{

	static bool initialized;

	if (initialized)

		return 0;

	else

		initialized = true;

	return i2c_add_driver(&fan53555_regulator_driver);

}

EXPORT_SYMBOL(fan53555_regulator_init);

module_init(fan53555_regulator_init);

static void __exit fan53555_regulator_exit(void)

{

	i2c_del_driver(&fan53555_regulator_driver);

}

module_exit(fan53555_regulator_exit);

MODULE_AUTHOR("Yunfan Zhang <yfzhang@marvell.com>");

MODULE_DESCRIPTION("FAN53555 regulator driver");

	unsigned int sleep_vsel_id;

};

#ifdef CONFIG_REGULATOR_FAN53555

int __init fan53555_regulator_init(void);

#else

static inline int __init fan53555_regulator_init(void) { return 0; }

#endif

#endif /* __FAN53555_H__ */