root/drivers/regulator/mp886x.c
// SPDX-License-Identifier: GPL-2.0
//
// MP8867/MP8869 regulator driver
//
// Copyright (C) 2020 Synaptics Incorporated
//
// Author: Jisheng Zhang <jszhang@kernel.org>

#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>

#define MP886X_VSEL             0x00
#define  MP886X_V_BOOT          (1 << 7)
#define MP886X_SYSCNTLREG1      0x01
#define  MP886X_MODE            (1 << 0)
#define  MP886X_SLEW_SHIFT      3
#define  MP886X_SLEW_MASK       (0x7 << MP886X_SLEW_SHIFT)
#define  MP886X_GO              (1 << 6)
#define  MP886X_EN              (1 << 7)
#define MP8869_SYSCNTLREG2      0x02

struct mp886x_cfg_info {
        const struct regulator_ops *rops;
        const unsigned int slew_rates[8];
        const int switch_freq[4];
        const u8 fs_reg;
        const u8 fs_shift;
};

struct mp886x_device_info {
        struct device *dev;
        struct regulator_desc desc;
        struct regulator_init_data *regulator;
        struct gpio_desc *en_gpio;
        const struct mp886x_cfg_info *ci;
        u32 r[2];
        unsigned int sel;
};

static void mp886x_set_switch_freq(struct mp886x_device_info *di,
                                   struct regmap *regmap,
                                   u32 freq)
{
        const struct mp886x_cfg_info *ci = di->ci;
        int i;

        for (i = 0; i < ARRAY_SIZE(ci->switch_freq); i++) {
                if (freq == ci->switch_freq[i]) {
                        regmap_update_bits(regmap, ci->fs_reg,
                                  0x3 << ci->fs_shift, i << ci->fs_shift);
                        return;
                }
        }

        dev_err(di->dev, "invalid frequency %d\n", freq);
}

static int mp886x_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
        switch (mode) {
        case REGULATOR_MODE_FAST:
                regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
                                   MP886X_MODE, MP886X_MODE);
                break;
        case REGULATOR_MODE_NORMAL:
                regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
                                   MP886X_MODE, 0);
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static unsigned int mp886x_get_mode(struct regulator_dev *rdev)
{
        u32 val;
        int ret;

        ret = regmap_read(rdev->regmap, MP886X_SYSCNTLREG1, &val);
        if (ret < 0)
                return ret;
        if (val & MP886X_MODE)
                return REGULATOR_MODE_FAST;
        else
                return REGULATOR_MODE_NORMAL;
}

static int mp8869_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
{
        int ret;

        ret = regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
                                 MP886X_GO, MP886X_GO);
        if (ret < 0)
                return ret;

        sel <<= ffs(rdev->desc->vsel_mask) - 1;
        return regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
                                  MP886X_V_BOOT | rdev->desc->vsel_mask, sel);
}

static inline unsigned int mp8869_scale(unsigned int uv, u32 r1, u32 r2)
{
        u32 tmp = uv * r1 / r2;

        return uv + tmp;
}

static int mp8869_get_voltage_sel(struct regulator_dev *rdev)
{
        struct mp886x_device_info *di = rdev_get_drvdata(rdev);
        int ret, uv;
        unsigned int val;
        bool fbloop;

        ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
        if (ret)
                return ret;

        fbloop = val & MP886X_V_BOOT;
        if (fbloop) {
                uv = rdev->desc->min_uV;
                uv = mp8869_scale(uv, di->r[0], di->r[1]);
                return regulator_map_voltage_linear(rdev, uv, uv);
        }

        val &= rdev->desc->vsel_mask;
        val >>= ffs(rdev->desc->vsel_mask) - 1;

        return val;
}

static const struct regulator_ops mp8869_regulator_ops = {
        .set_voltage_sel = mp8869_set_voltage_sel,
        .get_voltage_sel = mp8869_get_voltage_sel,
        .set_voltage_time_sel = regulator_set_voltage_time_sel,
        .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 = mp886x_set_mode,
        .get_mode = mp886x_get_mode,
        .set_ramp_delay = regulator_set_ramp_delay_regmap,
};

static const struct mp886x_cfg_info mp8869_ci = {
        .rops = &mp8869_regulator_ops,
        .slew_rates = {
                40000,
                30000,
                20000,
                10000,
                5000,
                2500,
                1250,
                625,
        },
        .switch_freq = {
                500000,
                750000,
                1000000,
                1250000,
        },
        .fs_reg = MP8869_SYSCNTLREG2,
        .fs_shift = 4,
};

static int mp8867_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
{
        struct mp886x_device_info *di = rdev_get_drvdata(rdev);
        int ret, delta;

        ret = mp8869_set_voltage_sel(rdev, sel);
        if (ret < 0)
                return ret;

        delta = di->sel - sel;
        if (abs(delta) <= 5)
                ret = regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
                                         MP886X_GO, 0);
        di->sel = sel;

        return ret;
}

static int mp8867_get_voltage_sel(struct regulator_dev *rdev)
{
        struct mp886x_device_info *di = rdev_get_drvdata(rdev);
        int ret, uv;
        unsigned int val;
        bool fbloop;

        ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
        if (ret)
                return ret;

        fbloop = val & MP886X_V_BOOT;

        val &= rdev->desc->vsel_mask;
        val >>= ffs(rdev->desc->vsel_mask) - 1;

        if (fbloop) {
                uv = regulator_list_voltage_linear(rdev, val);
                uv = mp8869_scale(uv, di->r[0], di->r[1]);
                return regulator_map_voltage_linear(rdev, uv, uv);
        }

        return val;
}

static const struct regulator_ops mp8867_regulator_ops = {
        .set_voltage_sel = mp8867_set_voltage_sel,
        .get_voltage_sel = mp8867_get_voltage_sel,
        .set_voltage_time_sel = regulator_set_voltage_time_sel,
        .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 = mp886x_set_mode,
        .get_mode = mp886x_get_mode,
        .set_ramp_delay = regulator_set_ramp_delay_regmap,
};

static const struct mp886x_cfg_info mp8867_ci = {
        .rops = &mp8867_regulator_ops,
        .slew_rates = {
                64000,
                32000,
                16000,
                8000,
                4000,
                2000,
                1000,
                500,
        },
        .switch_freq = {
                500000,
                750000,
                1000000,
                1500000,
        },
        .fs_reg = MP886X_SYSCNTLREG1,
        .fs_shift = 1,
};

static int mp886x_regulator_register(struct mp886x_device_info *di,
                                     struct regulator_config *config)
{
        struct regulator_desc *rdesc = &di->desc;
        struct regulator_dev *rdev;

        rdesc->name = "mp886x-reg";
        rdesc->supply_name = "vin";
        rdesc->ops = di->ci->rops;
        rdesc->type = REGULATOR_VOLTAGE;
        rdesc->n_voltages = 128;
        rdesc->enable_reg = MP886X_SYSCNTLREG1;
        rdesc->enable_mask = MP886X_EN;
        rdesc->min_uV = 600000;
        rdesc->uV_step = 10000;
        rdesc->vsel_reg = MP886X_VSEL;
        rdesc->vsel_mask = 0x3f;
        rdesc->ramp_reg = MP886X_SYSCNTLREG1;
        rdesc->ramp_mask = MP886X_SLEW_MASK;
        rdesc->ramp_delay_table = di->ci->slew_rates;
        rdesc->n_ramp_values = ARRAY_SIZE(di->ci->slew_rates);
        rdesc->owner = THIS_MODULE;

        rdev = devm_regulator_register(di->dev, &di->desc, config);
        if (IS_ERR(rdev))
                return PTR_ERR(rdev);
        di->sel = rdesc->ops->get_voltage_sel(rdev);
        return 0;
}

static const struct regmap_config mp886x_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
};

static int mp886x_i2c_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct device_node *np = dev->of_node;
        struct mp886x_device_info *di;
        struct regulator_config config = { };
        struct regmap *regmap;
        u32 freq;
        int ret;

        di = devm_kzalloc(dev, sizeof(struct mp886x_device_info), GFP_KERNEL);
        if (!di)
                return -ENOMEM;

        di->regulator = of_get_regulator_init_data(dev, np, &di->desc);
        if (!di->regulator) {
                dev_err(dev, "Platform data not found!\n");
                return -EINVAL;
        }

        ret = of_property_read_u32_array(np, "mps,fb-voltage-divider",
                                         di->r, 2);
        if (ret)
                return ret;

        di->en_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
        if (IS_ERR(di->en_gpio))
                return PTR_ERR(di->en_gpio);

        di->ci = i2c_get_match_data(client);
        di->dev = dev;

        regmap = devm_regmap_init_i2c(client, &mp886x_regmap_config);
        if (IS_ERR(regmap)) {
                dev_err(dev, "Failed to allocate regmap!\n");
                return PTR_ERR(regmap);
        }
        i2c_set_clientdata(client, di);

        config.dev = di->dev;
        config.init_data = di->regulator;
        config.regmap = regmap;
        config.driver_data = di;
        config.of_node = np;

        if (!of_property_read_u32(np, "mps,switch-frequency-hz", &freq))
                mp886x_set_switch_freq(di, regmap, freq);

        ret = mp886x_regulator_register(di, &config);
        if (ret < 0)
                dev_err(dev, "Failed to register regulator!\n");
        return ret;
}

static const struct of_device_id mp886x_dt_ids[] = {
        { .compatible = "mps,mp8867", .data = &mp8867_ci },
        { .compatible = "mps,mp8869", .data = &mp8869_ci },
        { }
};
MODULE_DEVICE_TABLE(of, mp886x_dt_ids);

static const struct i2c_device_id mp886x_id[] = {
        { "mp8867", (kernel_ulong_t)&mp8867_ci },
        { "mp8869", (kernel_ulong_t)&mp8869_ci },
        { },
};
MODULE_DEVICE_TABLE(i2c, mp886x_id);

static struct i2c_driver mp886x_regulator_driver = {
        .driver = {
                .name = "mp886x-regulator",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = mp886x_dt_ids,
        },
        .probe = mp886x_i2c_probe,
        .id_table = mp886x_id,
};
module_i2c_driver(mp886x_regulator_driver);

MODULE_AUTHOR("Jisheng Zhang <jszhang@kernel.org>");
MODULE_DESCRIPTION("MP886x regulator driver");
MODULE_LICENSE("GPL v2");