tps62360-regulator.c

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/*
 * tps62360.c -- TI tps62360
 *
 * Driver for processor core supply tps62360, tps62361B, tps62362 and tps62363.
 *
 * Copyright (c) 2012, NVIDIA Corporation.
 *
 * Author: Laxman Dewangan <[email protected]>
 *
 * 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
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/regulator/of_regulator.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/tps62360.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/regmap.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

#define FORCE_PWM_ENABLE    BIT(7)

enum chips {TPS62360, TPS62361, TPS62362, TPS62363};

#define TPS62360_BASE_VOLTAGE   770000
#define TPS62360_N_VOLTAGES 64

#define TPS62361_BASE_VOLTAGE   500000
#define TPS62361_N_VOLTAGES 128

/* tps 62360 chip information */
struct tps62360_chip {
    struct device *dev;
    struct regulator_desc desc;
    struct regulator_dev *rdev;
    struct regmap *regmap;
    int vsel0_gpio;
    int vsel1_gpio;
    u8 voltage_reg_mask;
    bool en_internal_pulldn;
    bool en_discharge;
    bool valid_gpios;
    int lru_index[4];
    int curr_vset_vsel[4];
    int curr_vset_id;
};

/*
 * find_voltage_set_register: Find new voltage configuration register
 * (VSET) id.
 * The finding of the new VSET register will be based on the LRU mechanism.
 * Each VSET register will have different voltage configured . This
 * Function will look if any of the VSET register have requested voltage set
 * or not.
 *     - If it is already there then it will make that register as most
 *       recently used and return as found so that caller need not to set
 *       the VSET register but need to set the proper gpios to select this
 *       VSET register.
 *     - If requested voltage is not found then it will use the least
 *       recently mechanism to get new VSET register for new configuration
 *       and will return not_found so that caller need to set new VSET
 *       register and then gpios (both).
 */
static bool find_voltage_set_register(struct tps62360_chip *tps,
        int req_vsel, int *vset_reg_id)
{
    int i;
    bool found = false;
    int new_vset_reg = tps->lru_index[3];
    int found_index = 3;

    for (i = 0; i < 4; ++i) {
        if (tps->curr_vset_vsel[tps->lru_index[i]] == req_vsel) {
            new_vset_reg = tps->lru_index[i];
            found_index = i;
            found = true;
            goto update_lru_index;
        }
    }

update_lru_index:
    for (i = found_index; i > 0; i--)
        tps->lru_index[i] = tps->lru_index[i - 1];

    tps->lru_index[0] = new_vset_reg;
    *vset_reg_id = new_vset_reg;
    return found;
}

static int tps62360_dcdc_get_voltage_sel(struct regulator_dev *dev)
{
    struct tps62360_chip *tps = rdev_get_drvdata(dev);
    int vsel;
    unsigned int data;
    int ret;

    ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
    if (ret < 0) {
        dev_err(tps->dev, "%s(): register %d read failed with err %d\n",
            __func__, REG_VSET0 + tps->curr_vset_id, ret);
        return ret;
    }
    vsel = (int)data & tps->voltage_reg_mask;
    return vsel;
}

static int tps62360_dcdc_set_voltage_sel(struct regulator_dev *dev,
                     unsigned selector)
{
    struct tps62360_chip *tps = rdev_get_drvdata(dev);
    int ret;
    bool found = false;
    int new_vset_id = tps->curr_vset_id;

    /*
     * If gpios are available to select the VSET register then least
     * recently used register for new configuration.
     */
    if (tps->valid_gpios)
        found = find_voltage_set_register(tps, selector, &new_vset_id);

    if (!found) {
        ret = regmap_update_bits(tps->regmap, REG_VSET0 + new_vset_id,
                tps->voltage_reg_mask, selector);
        if (ret < 0) {
            dev_err(tps->dev,
                "%s(): register %d update failed with err %d\n",
                 __func__, REG_VSET0 + new_vset_id, ret);
            return ret;
        }
        tps->curr_vset_id = new_vset_id;
        tps->curr_vset_vsel[new_vset_id] = selector;
    }

    /* Select proper VSET register vio gpios */
    if (tps->valid_gpios) {
        gpio_set_value_cansleep(tps->vsel0_gpio, new_vset_id & 0x1);
        gpio_set_value_cansleep(tps->vsel1_gpio,
                    (new_vset_id >> 1) & 0x1);
    }
    return 0;
}

static int tps62360_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
    struct tps62360_chip *tps = rdev_get_drvdata(rdev);
    int i;
    int val;
    int ret;

    /* Enable force PWM mode in FAST mode only. */
    switch (mode) {
    case REGULATOR_MODE_FAST:
        val = FORCE_PWM_ENABLE;
        break;

    case REGULATOR_MODE_NORMAL:
        val = 0;
        break;

    default:
        return -EINVAL;
    }

    if (!tps->valid_gpios) {
        ret = regmap_update_bits(tps->regmap,
            REG_VSET0 + tps->curr_vset_id, FORCE_PWM_ENABLE, val);
        if (ret < 0)
            dev_err(tps->dev,
                "%s(): register %d update failed with err %d\n",
                __func__, REG_VSET0 + tps->curr_vset_id, ret);
        return ret;
    }

    /* If gpios are valid then all register set need to be control */
    for (i = 0; i < 4; ++i) {
        ret = regmap_update_bits(tps->regmap,
                    REG_VSET0 + i, FORCE_PWM_ENABLE, val);
        if (ret < 0) {
            dev_err(tps->dev,
                "%s(): register %d update failed with err %d\n",
                __func__, REG_VSET0 + i, ret);
            return ret;
        }
    }
    return ret;
}

static unsigned int tps62360_get_mode(struct regulator_dev *rdev)
{
    struct tps62360_chip *tps = rdev_get_drvdata(rdev);
    unsigned int data;
    int ret;

    ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
    if (ret < 0) {
        dev_err(tps->dev, "%s(): register %d read failed with err %d\n",
            __func__, REG_VSET0 + tps->curr_vset_id, ret);
        return ret;
    }
    return (data & FORCE_PWM_ENABLE) ?
                REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
}

static struct regulator_ops tps62360_dcdc_ops = {
    .get_voltage_sel    = tps62360_dcdc_get_voltage_sel,
    .set_voltage_sel    = tps62360_dcdc_set_voltage_sel,
    .list_voltage       = regulator_list_voltage_linear,
    .map_voltage        = regulator_map_voltage_linear,
    .set_voltage_time_sel   = regulator_set_voltage_time_sel,
    .set_mode       = tps62360_set_mode,
    .get_mode       = tps62360_get_mode,
};

static int __devinit tps62360_init_dcdc(struct tps62360_chip *tps,
        struct tps62360_regulator_platform_data *pdata)
{
    int ret;
    unsigned int ramp_ctrl;

    /* Initialize internal pull up/down control */
    if (tps->en_internal_pulldn)
        ret = regmap_write(tps->regmap, REG_CONTROL, 0xE0);
    else
        ret = regmap_write(tps->regmap, REG_CONTROL, 0x0);
    if (ret < 0) {
        dev_err(tps->dev,
            "%s(): register %d write failed with err %d\n",
            __func__, REG_CONTROL, ret);
        return ret;
    }

    /* Reset output discharge path to reduce power consumption */
    ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), 0);
    if (ret < 0) {
        dev_err(tps->dev,
            "%s(): register %d update failed with err %d\n",
            __func__, REG_RAMPCTRL, ret);
        return ret;
    }

    /* Get ramp value from ramp control register */
    ret = regmap_read(tps->regmap, REG_RAMPCTRL, &ramp_ctrl);
    if (ret < 0) {
        dev_err(tps->dev,
            "%s(): register %d read failed with err %d\n",
            __func__, REG_RAMPCTRL, ret);
        return ret;
    }
    ramp_ctrl = (ramp_ctrl >> 4) & 0x7;

    /* ramp mV/us = 32/(2^ramp_ctrl) */
    tps->desc.ramp_delay = DIV_ROUND_UP(32000, BIT(ramp_ctrl));
    return ret;
}

static const struct regmap_config tps62360_regmap_config = {
    .reg_bits       = 8,
    .val_bits       = 8,
    .max_register       = REG_CHIPID,
    .cache_type     = REGCACHE_RBTREE,
};

static struct tps62360_regulator_platform_data *
    of_get_tps62360_platform_data(struct device *dev)
{
    struct tps62360_regulator_platform_data *pdata;
    struct device_node *np = dev->of_node;

    pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
    if (!pdata) {
        dev_err(dev, "Memory alloc failed for platform data\n");
        return NULL;
    }

    pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node);
    if (!pdata->reg_init_data) {
        dev_err(dev, "Not able to get OF regulator init data\n");
        return NULL;
    }

    pdata->vsel0_gpio = of_get_named_gpio(np, "vsel0-gpio", 0);
    pdata->vsel1_gpio = of_get_named_gpio(np, "vsel1-gpio", 0);

    if (of_find_property(np, "ti,vsel0-state-high", NULL))
        pdata->vsel0_def_state = 1;

    if (of_find_property(np, "ti,vsel1-state-high", NULL))
        pdata->vsel1_def_state = 1;

    if (of_find_property(np, "ti,enable-pull-down", NULL))
        pdata->en_internal_pulldn = true;

    if (of_find_property(np, "ti,enable-vout-discharge", NULL))
        pdata->en_discharge = true;

    return pdata;
}

#if defined(CONFIG_OF)
static const struct of_device_id tps62360_of_match[] = {
     { .compatible = "ti,tps62360", .data = (void *)TPS62360},
     { .compatible = "ti,tps62361", .data = (void *)TPS62361},
     { .compatible = "ti,tps62362", .data = (void *)TPS62362},
     { .compatible = "ti,tps62363", .data = (void *)TPS62363},
    {},
};
MODULE_DEVICE_TABLE(of, tps62360_of_match);
#endif

static int __devinit tps62360_probe(struct i2c_client *client,
                     const struct i2c_device_id *id)
{
    struct regulator_config config = { };
    struct tps62360_regulator_platform_data *pdata;
    struct regulator_dev *rdev;
    struct tps62360_chip *tps;
    int ret;
    int i;
    int chip_id;

    pdata = client->dev.platform_data;
    chip_id = id->driver_data;

    if (client->dev.of_node) {
        const struct of_device_id *match;
        match = of_match_device(of_match_ptr(tps62360_of_match),
                &client->dev);
        if (!match) {
            dev_err(&client->dev, "Error: No device match found\n");
            return -ENODEV;
        }
        chip_id = (int)match->data;
        if (!pdata)
            pdata = of_get_tps62360_platform_data(&client->dev);
    }

    if (!pdata) {
        dev_err(&client->dev, "%s(): Platform data not found\n",
                        __func__);
        return -EIO;
    }

    tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
    if (!tps) {
        dev_err(&client->dev, "%s(): Memory allocation failed\n",
                        __func__);
        return -ENOMEM;
    }

    tps->en_discharge = pdata->en_discharge;
    tps->en_internal_pulldn = pdata->en_internal_pulldn;
    tps->vsel0_gpio = pdata->vsel0_gpio;
    tps->vsel1_gpio = pdata->vsel1_gpio;
    tps->dev = &client->dev;

    switch (chip_id) {
    case TPS62360:
    case TPS62362:
        tps->desc.min_uV = TPS62360_BASE_VOLTAGE;
        tps->voltage_reg_mask = 0x3F;
        tps->desc.n_voltages = TPS62360_N_VOLTAGES;
        break;
    case TPS62361:
    case TPS62363:
        tps->desc.min_uV = TPS62361_BASE_VOLTAGE;
        tps->voltage_reg_mask = 0x7F;
        tps->desc.n_voltages = TPS62361_N_VOLTAGES;
        break;
    default:
        return -ENODEV;
    }

    tps->desc.name = id->name;
    tps->desc.id = 0;
    tps->desc.ops = &tps62360_dcdc_ops;
    tps->desc.type = REGULATOR_VOLTAGE;
    tps->desc.owner = THIS_MODULE;
    tps->desc.uV_step = 10000;

    tps->regmap = devm_regmap_init_i2c(client, &tps62360_regmap_config);
    if (IS_ERR(tps->regmap)) {
        ret = PTR_ERR(tps->regmap);
        dev_err(&client->dev,
            "%s(): regmap allocation failed with err %d\n",
            __func__, ret);
        return ret;
    }
    i2c_set_clientdata(client, tps);

    tps->curr_vset_id = (pdata->vsel1_def_state & 1) * 2 +
                (pdata->vsel0_def_state & 1);
    tps->lru_index[0] = tps->curr_vset_id;
    tps->valid_gpios = false;

    if (gpio_is_valid(tps->vsel0_gpio) && gpio_is_valid(tps->vsel1_gpio)) {
        int gpio_flags;
        gpio_flags = (pdata->vsel0_def_state) ?
                GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
        ret = devm_gpio_request_one(&client->dev, tps->vsel0_gpio,
                gpio_flags, "tps62360-vsel0");
        if (ret) {
            dev_err(&client->dev,
                "%s(): Could not obtain vsel0 GPIO %d: %d\n",
                __func__, tps->vsel0_gpio, ret);
            return ret;
        }

        gpio_flags = (pdata->vsel1_def_state) ?
                GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
        ret = devm_gpio_request_one(&client->dev, tps->vsel1_gpio,
                gpio_flags, "tps62360-vsel1");
        if (ret) {
            dev_err(&client->dev,
                "%s(): Could not obtain vsel1 GPIO %d: %d\n",
                __func__, tps->vsel1_gpio, ret);
            return ret;
        }
        tps->valid_gpios = true;

        /*
         * Initialize the lru index with vset_reg id
         * The index 0 will be most recently used and
         * set with the tps->curr_vset_id */
        for (i = 0; i < 4; ++i)
            tps->lru_index[i] = i;
        tps->lru_index[0] = tps->curr_vset_id;
        tps->lru_index[tps->curr_vset_id] = 0;
    }

    ret = tps62360_init_dcdc(tps, pdata);
    if (ret < 0) {
        dev_err(tps->dev, "%s(): Init failed with err = %d\n",
                __func__, ret);
        return ret;
    }

    config.dev = &client->dev;
    config.init_data = pdata->reg_init_data;
    config.driver_data = tps;
    config.of_node = client->dev.of_node;

    /* Register the regulators */
    rdev = regulator_register(&tps->desc, &config);
    if (IS_ERR(rdev)) {
        dev_err(tps->dev,
            "%s(): regulator register failed with err %s\n",
            __func__, id->name);
        return PTR_ERR(rdev);
    }

    tps->rdev = rdev;
    return 0;
}

static int __devexit tps62360_remove(struct i2c_client *client)
{
    struct tps62360_chip *tps = i2c_get_clientdata(client);

    regulator_unregister(tps->rdev);
    return 0;
}

static void tps62360_shutdown(struct i2c_client *client)
{
    struct tps62360_chip *tps = i2c_get_clientdata(client);
    int st;

    if (!tps->en_discharge)
        return;

    /* Configure the output discharge path */
    st = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2));
    if (st < 0)
        dev_err(tps->dev,
            "%s(): register %d update failed with err %d\n",
            __func__, REG_RAMPCTRL, st);
}

static const struct i2c_device_id tps62360_id[] = {
    {.name = "tps62360", .driver_data = TPS62360},
    {.name = "tps62361", .driver_data = TPS62361},
    {.name = "tps62362", .driver_data = TPS62362},
    {.name = "tps62363", .driver_data = TPS62363},
    {},
};

MODULE_DEVICE_TABLE(i2c, tps62360_id);

static struct i2c_driver tps62360_i2c_driver = {
    .driver = {
        .name = "tps62360",
        .owner = THIS_MODULE,
        .of_match_table = of_match_ptr(tps62360_of_match),
    },
    .probe = tps62360_probe,
    .remove = __devexit_p(tps62360_remove),
    .shutdown = tps62360_shutdown,
    .id_table = tps62360_id,
};

static int __init tps62360_init(void)
{
    return i2c_add_driver(&tps62360_i2c_driver);
}
subsys_initcall(tps62360_init);

static void __exit tps62360_cleanup(void)
{
    i2c_del_driver(&tps62360_i2c_driver);
}
module_exit(tps62360_cleanup);

MODULE_AUTHOR("Laxman Dewangan <[email protected]>");
MODULE_DESCRIPTION("TPS6236x voltage regulator driver");
MODULE_LICENSE("GPL v2");