root/drivers/regulator/ltc3589.c
// SPDX-License-Identifier: GPL-2.0
//
// Linear Technology LTC3589,LTC3589-1 regulator support
//
// Copyright (c) 2014 Philipp Zabel <p.zabel@pengutronix.de>, Pengutronix

#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>

#define DRIVER_NAME             "ltc3589"

#define LTC3589_IRQSTAT         0x02
#define LTC3589_SCR1            0x07
#define LTC3589_OVEN            0x10
#define LTC3589_SCR2            0x12
#define LTC3589_PGSTAT          0x13
#define LTC3589_VCCR            0x20
#define LTC3589_CLIRQ           0x21
#define LTC3589_B1DTV1          0x23
#define LTC3589_B1DTV2          0x24
#define LTC3589_VRRCR           0x25
#define LTC3589_B2DTV1          0x26
#define LTC3589_B2DTV2          0x27
#define LTC3589_B3DTV1          0x29
#define LTC3589_B3DTV2          0x2a
#define LTC3589_L2DTV1          0x32
#define LTC3589_L2DTV2          0x33

#define LTC3589_IRQSTAT_PGOOD_TIMEOUT   BIT(3)
#define LTC3589_IRQSTAT_UNDERVOLT_WARN  BIT(4)
#define LTC3589_IRQSTAT_UNDERVOLT_FAULT BIT(5)
#define LTC3589_IRQSTAT_THERMAL_WARN    BIT(6)
#define LTC3589_IRQSTAT_THERMAL_FAULT   BIT(7)

#define LTC3589_OVEN_SW1                BIT(0)
#define LTC3589_OVEN_SW2                BIT(1)
#define LTC3589_OVEN_SW3                BIT(2)
#define LTC3589_OVEN_BB_OUT             BIT(3)
#define LTC3589_OVEN_LDO2               BIT(4)
#define LTC3589_OVEN_LDO3               BIT(5)
#define LTC3589_OVEN_LDO4               BIT(6)
#define LTC3589_OVEN_SW_CTRL            BIT(7)

#define LTC3589_VCCR_SW1_GO             BIT(0)
#define LTC3589_VCCR_SW2_GO             BIT(2)
#define LTC3589_VCCR_SW3_GO             BIT(4)
#define LTC3589_VCCR_LDO2_GO            BIT(6)

#define LTC3589_VRRCR_SW1_RAMP_MASK     GENMASK(1, 0)
#define LTC3589_VRRCR_SW2_RAMP_MASK     GENMASK(3, 2)
#define LTC3589_VRRCR_SW3_RAMP_MASK     GENMASK(5, 4)
#define LTC3589_VRRCR_LDO2_RAMP_MASK    GENMASK(7, 6)

enum ltc3589_reg {
        LTC3589_SW1,
        LTC3589_SW2,
        LTC3589_SW3,
        LTC3589_BB_OUT,
        LTC3589_LDO1,
        LTC3589_LDO2,
        LTC3589_LDO3,
        LTC3589_LDO4,
        LTC3589_NUM_REGULATORS,
};

struct ltc3589_info {
        const unsigned int *volt_table;
        int fixed_uV;
};

struct ltc3589 {
        struct regmap *regmap;
        struct device *dev;
        struct regulator_desc regulator_descs[LTC3589_NUM_REGULATORS];
        struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
};

static const int ltc3589_ldo4[] = {
        2800000, 2500000, 1800000, 3300000,
};

static const int ltc3589_12_ldo4[] = {
        1200000, 1800000, 2500000, 3200000,
};

static const unsigned int ltc3589_ramp_table[] = {
        880, 1750, 3500, 7000
};

static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
{
        struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
        int sel;

        sel = regulator_map_voltage_linear(rdev, uV, uV);
        if (sel < 0)
                return sel;

        /* DTV2 register follows right after the corresponding DTV1 register */
        return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
                                  rdev->desc->vsel_mask, sel);
}

static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
                                    unsigned int mode)
{
        struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
        int mask, bit = 0;

        /* VCCR reference selects are right next to the VCCR go bits */
        mask = rdev->desc->apply_bit << 1;

        if (mode == REGULATOR_MODE_STANDBY)
                bit = mask;     /* Select DTV2 */

        mask |= rdev->desc->apply_bit;
        bit |= rdev->desc->apply_bit;
        return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
}

/* SW1, SW2, SW3, LDO2 */
static const struct regulator_ops ltc3589_linear_regulator_ops = {
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .list_voltage = regulator_list_voltage_linear,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_ramp_delay = regulator_set_ramp_delay_regmap,
        .set_voltage_time_sel = regulator_set_voltage_time_sel,
        .set_suspend_voltage = ltc3589_set_suspend_voltage,
        .set_suspend_mode = ltc3589_set_suspend_mode,
};

/* BB_OUT, LDO3 */
static const struct regulator_ops ltc3589_fixed_regulator_ops = {
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
};

/* LDO1 */
static const struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
};

/* LDO4 */
static const struct regulator_ops ltc3589_table_regulator_ops = {
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .list_voltage = regulator_list_voltage_table,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
};

static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
{
        uint64_t tmp;

        if (uV == 0)
                return 0;

        tmp = (uint64_t)uV * r1;
        do_div(tmp, r2);
        return uV + (unsigned int)tmp;
}

static int ltc3589_of_parse_cb(struct device_node *np,
                               const struct regulator_desc *desc,
                               struct regulator_config *config)
{
        struct ltc3589 *ltc3589 = config->driver_data;
        struct regulator_desc *rdesc = &ltc3589->regulator_descs[desc->id];
        u32 r[2];
        int ret;

        /* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
        if (desc->id >= LTC3589_LDO3)
                return 0;

        ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2);
        if (ret) {
                dev_err(ltc3589->dev, "Failed to parse voltage divider: %d\n",
                        ret);
                return ret;
        }

        if (!r[0] || !r[1])
                return 0;

        rdesc->min_uV = ltc3589_scale(desc->min_uV, r[0], r[1]);
        rdesc->uV_step = ltc3589_scale(desc->uV_step, r[0], r[1]);
        rdesc->fixed_uV = ltc3589_scale(desc->fixed_uV, r[0], r[1]);

        return 0;
}

#define LTC3589_REG(_name, _of_name, _ops, en_bit, dtv1_reg, dtv_mask)  \
        [LTC3589_ ## _name] = {                                         \
                .name = #_name,                                         \
                .of_match = of_match_ptr(#_of_name),                    \
                .regulators_node = of_match_ptr("regulators"),          \
                .of_parse_cb = ltc3589_of_parse_cb,                     \
                .n_voltages = (dtv_mask) + 1,                           \
                .fixed_uV = (dtv_mask) ? 0 : 800000,                    \
                .ops = &ltc3589_ ## _ops ## _regulator_ops,             \
                .type = REGULATOR_VOLTAGE,                              \
                .id = LTC3589_ ## _name,                                \
                .owner = THIS_MODULE,                                   \
                .vsel_reg = (dtv1_reg),                                 \
                .vsel_mask = (dtv_mask),                                \
                .enable_reg = (en_bit) ? LTC3589_OVEN : 0,              \
                .enable_mask = (en_bit),                                \
        }

#define LTC3589_LINEAR_REG(_name, _of_name, _dtv1)                      \
        [LTC3589_ ## _name] = {                                         \
                .name = #_name,                                         \
                .of_match = of_match_ptr(#_of_name),                    \
                .regulators_node = of_match_ptr("regulators"),          \
                .of_parse_cb = ltc3589_of_parse_cb,                     \
                .n_voltages = 32,                                       \
                .min_uV = 362500,                                       \
                .uV_step = 12500,                                       \
                .ramp_delay = 1750,                                     \
                .ops = &ltc3589_linear_regulator_ops,                   \
                .type = REGULATOR_VOLTAGE,                              \
                .id = LTC3589_ ## _name,                                \
                .owner = THIS_MODULE,                                   \
                .vsel_reg = LTC3589_ ## _dtv1,                          \
                .vsel_mask = 0x1f,                                      \
                .apply_reg = LTC3589_VCCR,                              \
                .apply_bit = LTC3589_VCCR_ ## _name ## _GO,             \
                .enable_reg = LTC3589_OVEN,                             \
                .enable_mask = (LTC3589_OVEN_ ## _name),                \
                .ramp_reg = LTC3589_VRRCR,                              \
                .ramp_mask = LTC3589_VRRCR_ ## _name ## _RAMP_MASK,     \
                .ramp_delay_table = ltc3589_ramp_table,                 \
                .n_ramp_values = ARRAY_SIZE(ltc3589_ramp_table),        \
        }


#define LTC3589_FIXED_REG(_name, _of_name)                              \
        LTC3589_REG(_name, _of_name, fixed, LTC3589_OVEN_ ## _name, 0, 0)

static const struct regulator_desc ltc3589_regulators[] = {
        LTC3589_LINEAR_REG(SW1, sw1, B1DTV1),
        LTC3589_LINEAR_REG(SW2, sw2, B2DTV1),
        LTC3589_LINEAR_REG(SW3, sw3, B3DTV1),
        LTC3589_FIXED_REG(BB_OUT, bb-out),
        LTC3589_REG(LDO1, ldo1, fixed_standby, 0, 0, 0),
        LTC3589_LINEAR_REG(LDO2, ldo2, L2DTV1),
        LTC3589_FIXED_REG(LDO3, ldo3),
        LTC3589_REG(LDO4, ldo4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60),
};

static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LTC3589_IRQSTAT:
        case LTC3589_SCR1:
        case LTC3589_OVEN:
        case LTC3589_SCR2:
        case LTC3589_VCCR:
        case LTC3589_CLIRQ:
        case LTC3589_B1DTV1:
        case LTC3589_B1DTV2:
        case LTC3589_VRRCR:
        case LTC3589_B2DTV1:
        case LTC3589_B2DTV2:
        case LTC3589_B3DTV1:
        case LTC3589_B3DTV2:
        case LTC3589_L2DTV1:
        case LTC3589_L2DTV2:
                return true;
        }
        return false;
}

static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LTC3589_IRQSTAT:
        case LTC3589_SCR1:
        case LTC3589_OVEN:
        case LTC3589_SCR2:
        case LTC3589_PGSTAT:
        case LTC3589_VCCR:
        case LTC3589_B1DTV1:
        case LTC3589_B1DTV2:
        case LTC3589_VRRCR:
        case LTC3589_B2DTV1:
        case LTC3589_B2DTV2:
        case LTC3589_B3DTV1:
        case LTC3589_B3DTV2:
        case LTC3589_L2DTV1:
        case LTC3589_L2DTV2:
                return true;
        }
        return false;
}

static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LTC3589_IRQSTAT:
        case LTC3589_PGSTAT:
        case LTC3589_VCCR:
                return true;
        }
        return false;
}

static const struct reg_default ltc3589_reg_defaults[] = {
        { LTC3589_SCR1,   0x00 },
        { LTC3589_OVEN,   0x00 },
        { LTC3589_SCR2,   0x00 },
        { LTC3589_VCCR,   0x00 },
        { LTC3589_B1DTV1, 0x19 },
        { LTC3589_B1DTV2, 0x19 },
        { LTC3589_VRRCR,  0xff },
        { LTC3589_B2DTV1, 0x19 },
        { LTC3589_B2DTV2, 0x19 },
        { LTC3589_B3DTV1, 0x19 },
        { LTC3589_B3DTV2, 0x19 },
        { LTC3589_L2DTV1, 0x19 },
        { LTC3589_L2DTV2, 0x19 },
};

static const struct regmap_config ltc3589_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .writeable_reg = ltc3589_writeable_reg,
        .readable_reg = ltc3589_readable_reg,
        .volatile_reg = ltc3589_volatile_reg,
        .max_register = LTC3589_L2DTV2,
        .reg_defaults = ltc3589_reg_defaults,
        .num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
        .use_single_read = true,
        .use_single_write = true,
        .cache_type = REGCACHE_MAPLE,
};

static irqreturn_t ltc3589_isr(int irq, void *dev_id)
{
        struct ltc3589 *ltc3589 = dev_id;
        unsigned int i, irqstat, event;

        regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);

        if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
                event = REGULATOR_EVENT_OVER_TEMP;
                for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
                        regulator_notifier_call_chain(ltc3589->regulators[i],
                                                      event, NULL);
        }

        if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
                event = REGULATOR_EVENT_UNDER_VOLTAGE;
                for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
                        regulator_notifier_call_chain(ltc3589->regulators[i],
                                                      event, NULL);
        }

        /* Clear warning condition */
        regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);

        return IRQ_HANDLED;
}

static int ltc3589_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        const struct ltc3589_info *info;
        struct regulator_desc *descs;
        struct ltc3589 *ltc3589;
        int i, ret;

        ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
        if (!ltc3589)
                return -ENOMEM;

        i2c_set_clientdata(client, ltc3589);
        info = i2c_get_match_data(client);
        ltc3589->dev = dev;

        descs = ltc3589->regulator_descs;
        memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
        descs[LTC3589_LDO3].fixed_uV = info->fixed_uV;
        descs[LTC3589_LDO4].volt_table = info->volt_table;

        ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
        if (IS_ERR(ltc3589->regmap)) {
                ret = PTR_ERR(ltc3589->regmap);
                dev_err(dev, "failed to initialize regmap: %d\n", ret);
                return ret;
        }

        for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
                struct regulator_desc *desc = &ltc3589->regulator_descs[i];
                struct regulator_config config = { };

                config.dev = dev;
                config.driver_data = ltc3589;

                ltc3589->regulators[i] = devm_regulator_register(dev, desc,
                                                                 &config);
                if (IS_ERR(ltc3589->regulators[i])) {
                        ret = PTR_ERR(ltc3589->regulators[i]);
                        dev_err(dev, "failed to register regulator %s: %d\n",
                                desc->name, ret);
                        return ret;
                }
        }

        if (client->irq) {
                ret = devm_request_threaded_irq(dev, client->irq, NULL,
                                                ltc3589_isr,
                                                IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                                                client->name, ltc3589);
                if (ret) {
                        dev_err(dev, "Failed to request IRQ: %d\n", ret);
                        return ret;
                }
        }

        return 0;
}

static const struct ltc3589_info ltc3589_info = {
        .fixed_uV = 1800000,
        .volt_table = ltc3589_ldo4,
};

static const struct ltc3589_info ltc3589_12_info = {
        .fixed_uV = 2800000,
        .volt_table = ltc3589_12_ldo4,
};

static const struct i2c_device_id ltc3589_i2c_id[] = {
        { "ltc3589",   (kernel_ulong_t)&ltc3589_info },
        { "ltc3589-1", (kernel_ulong_t)&ltc3589_12_info },
        { "ltc3589-2", (kernel_ulong_t)&ltc3589_12_info },
        { }
};
MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);

static const struct of_device_id __maybe_unused ltc3589_of_match[] = {
        { .compatible = "lltc,ltc3589",   .data = &ltc3589_info },
        { .compatible = "lltc,ltc3589-1", .data = &ltc3589_12_info },
        { .compatible = "lltc,ltc3589-2", .data = &ltc3589_12_info },
        { }
};
MODULE_DEVICE_TABLE(of, ltc3589_of_match);

static struct i2c_driver ltc3589_driver = {
        .driver = {
                .name = DRIVER_NAME,
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = of_match_ptr(ltc3589_of_match),
        },
        .probe = ltc3589_probe,
        .id_table = ltc3589_i2c_id,
};
module_i2c_driver(ltc3589_driver);

MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
MODULE_LICENSE("GPL v2");