// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Spreadtrum Communications Inc.

#include <linux/hwspinlock.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

/* PMIC global registers definition */
#define SC2730_MODULE_EN                0x1808
#define SC2731_MODULE_EN                0xc08
#define SC27XX_MODULE_ADC_EN            BIT(5)
#define SC2721_ARM_CLK_EN               0xc0c
#define SC2730_ARM_CLK_EN               0x180c
#define SC2731_ARM_CLK_EN               0xc10
#define SC27XX_CLK_ADC_EN               BIT(5)
#define SC27XX_CLK_ADC_CLK_EN           BIT(6)

/* ADC controller registers definition */
#define SC27XX_ADC_CTL                  0x0
#define SC27XX_ADC_CH_CFG               0x4
#define SC27XX_ADC_DATA                 0x4c
#define SC27XX_ADC_INT_EN               0x50
#define SC27XX_ADC_INT_CLR              0x54
#define SC27XX_ADC_INT_STS              0x58
#define SC27XX_ADC_INT_RAW              0x5c

/* Bits and mask definition for SC27XX_ADC_CTL register */
#define SC27XX_ADC_EN                   BIT(0)
#define SC27XX_ADC_CHN_RUN              BIT(1)
#define SC27XX_ADC_12BIT_MODE           BIT(2)
#define SC27XX_ADC_RUN_NUM_MASK         GENMASK(7, 4)
#define SC27XX_ADC_RUN_NUM_SHIFT        4

/* Bits and mask definition for SC27XX_ADC_CH_CFG register */
#define SC27XX_ADC_CHN_ID_MASK          GENMASK(4, 0)
#define SC27XX_ADC_SCALE_MASK           GENMASK(10, 9)
#define SC2721_ADC_SCALE_MASK           BIT(5)
#define SC27XX_ADC_SCALE_SHIFT          9
#define SC2721_ADC_SCALE_SHIFT          5

/* Bits definitions for SC27XX_ADC_INT_EN registers */
#define SC27XX_ADC_IRQ_EN               BIT(0)

/* Bits definitions for SC27XX_ADC_INT_CLR registers */
#define SC27XX_ADC_IRQ_CLR              BIT(0)

/* Bits definitions for SC27XX_ADC_INT_RAW registers */
#define SC27XX_ADC_IRQ_RAW              BIT(0)

/* Mask definition for SC27XX_ADC_DATA register */
#define SC27XX_ADC_DATA_MASK            GENMASK(11, 0)

/* Timeout (ms) for the trylock of hardware spinlocks */
#define SC27XX_ADC_HWLOCK_TIMEOUT       5000

/* Timeout (us) for ADC data conversion according to ADC datasheet */
#define SC27XX_ADC_RDY_TIMEOUT          1000000
#define SC27XX_ADC_POLL_RAW_STATUS      500

/* Maximum ADC channel number */
#define SC27XX_ADC_CHANNEL_MAX          32

/* ADC voltage ratio definition */
#define SC27XX_VOLT_RATIO(n, d)         \
        (((n) << SC27XX_RATIO_NUMERATOR_OFFSET) | (d))
#define SC27XX_RATIO_NUMERATOR_OFFSET   16
#define SC27XX_RATIO_DENOMINATOR_MASK   GENMASK(15, 0)

/* ADC specific channel reference voltage 3.5V */
#define SC27XX_ADC_REFVOL_VDD35         3500000

/* ADC default channel reference voltage is 2.8V */
#define SC27XX_ADC_REFVOL_VDD28         2800000

struct sc27xx_adc_data {
        struct device *dev;
        struct regulator *volref;
        struct regmap *regmap;
        /* lock to protect against multiple access to the device */
        struct mutex lock;
        /*
         * One hardware spinlock to synchronize between the multiple
         * subsystems which will access the unique ADC controller.
         */
        struct hwspinlock *hwlock;
        int channel_scale[SC27XX_ADC_CHANNEL_MAX];
        u32 base;
        int irq;
        const struct sc27xx_adc_variant_data *var_data;
};

/*
 * Since different PMICs of SC27xx series can have different
 * address and ratio, we should save ratio config and base
 * in the device data structure.
 */
struct sc27xx_adc_variant_data {
        u32 module_en;
        u32 clk_en;
        u32 scale_shift;
        u32 scale_mask;
        const struct sc27xx_adc_linear_graph *bscale_cal;
        const struct sc27xx_adc_linear_graph *sscale_cal;
        void (*init_scale)(struct sc27xx_adc_data *data);
        int (*get_ratio)(int channel, int scale);
        bool set_volref;
};

struct sc27xx_adc_linear_graph {
        int volt0;
        int adc0;
        int volt1;
        int adc1;
};

/*
 * According to the datasheet, we can convert one ADC value to one voltage value
 * through 2 points in the linear graph. If the voltage is less than 1.2v, we
 * should use the small-scale graph, and if more than 1.2v, we should use the
 * big-scale graph.
 */
static struct sc27xx_adc_linear_graph big_scale_graph = {
        4200, 3310,
        3600, 2832,
};

static struct sc27xx_adc_linear_graph small_scale_graph = {
        1000, 3413,
        100, 341,
};

static const struct sc27xx_adc_linear_graph sc2731_big_scale_graph_calib = {
        4200, 850,
        3600, 728,
};

static const struct sc27xx_adc_linear_graph sc2731_small_scale_graph_calib = {
        1000, 838,
        100, 84,
};

static const struct sc27xx_adc_linear_graph big_scale_graph_calib = {
        4200, 856,
        3600, 733,
};

static const struct sc27xx_adc_linear_graph small_scale_graph_calib = {
        1000, 833,
        100, 80,
};

static int sc27xx_adc_get_calib_data(u32 calib_data, int calib_adc)
{
        return ((calib_data & 0xff) + calib_adc - 128) * 4;
}

/* get the adc nvmem cell calibration data */
static int adc_nvmem_cell_calib_data(struct sc27xx_adc_data *data, const char *cell_name)
{
        struct nvmem_cell *cell;
        void *buf;
        u32 origin_calib_data = 0;
        size_t len;

        if (!data)
                return -EINVAL;

        cell = nvmem_cell_get(data->dev, cell_name);
        if (IS_ERR(cell))
                return PTR_ERR(cell);

        buf = nvmem_cell_read(cell, &len);
        if (IS_ERR(buf)) {
                nvmem_cell_put(cell);
                return PTR_ERR(buf);
        }

        memcpy(&origin_calib_data, buf, min(len, sizeof(u32)));

        kfree(buf);
        nvmem_cell_put(cell);
        return origin_calib_data;
}

static int sc27xx_adc_scale_calibration(struct sc27xx_adc_data *data,
                                        bool big_scale)
{
        const struct sc27xx_adc_linear_graph *calib_graph;
        struct sc27xx_adc_linear_graph *graph;
        const char *cell_name;
        u32 calib_data = 0;

        if (big_scale) {
                calib_graph = data->var_data->bscale_cal;
                graph = &big_scale_graph;
                cell_name = "big_scale_calib";
        } else {
                calib_graph = data->var_data->sscale_cal;
                graph = &small_scale_graph;
                cell_name = "small_scale_calib";
        }

        calib_data = adc_nvmem_cell_calib_data(data, cell_name);

        /* Only need to calibrate the adc values in the linear graph. */
        graph->adc0 = sc27xx_adc_get_calib_data(calib_data, calib_graph->adc0);
        graph->adc1 = sc27xx_adc_get_calib_data(calib_data >> 8,
                                                calib_graph->adc1);

        return 0;
}

static int sc2720_adc_get_ratio(int channel, int scale)
{
        switch (channel) {
        case 14:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(68, 900);
                case 1:
                        return SC27XX_VOLT_RATIO(68, 1760);
                case 2:
                        return SC27XX_VOLT_RATIO(68, 2327);
                case 3:
                        return SC27XX_VOLT_RATIO(68, 3654);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        case 16:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(48, 100);
                case 1:
                        return SC27XX_VOLT_RATIO(480, 1955);
                case 2:
                        return SC27XX_VOLT_RATIO(480, 2586);
                case 3:
                        return SC27XX_VOLT_RATIO(48, 406);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        case 21:
        case 22:
        case 23:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(3, 8);
                case 1:
                        return SC27XX_VOLT_RATIO(375, 1955);
                case 2:
                        return SC27XX_VOLT_RATIO(375, 2586);
                case 3:
                        return SC27XX_VOLT_RATIO(300, 3248);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        default:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(1, 1);
                case 1:
                        return SC27XX_VOLT_RATIO(1000, 1955);
                case 2:
                        return SC27XX_VOLT_RATIO(1000, 2586);
                case 3:
                        return SC27XX_VOLT_RATIO(100, 406);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        }
        return SC27XX_VOLT_RATIO(1, 1);
}

static int sc2721_adc_get_ratio(int channel, int scale)
{
        switch (channel) {
        case 1:
        case 2:
        case 3:
        case 4:
                return scale ? SC27XX_VOLT_RATIO(400, 1025) :
                        SC27XX_VOLT_RATIO(1, 1);
        case 5:
                return SC27XX_VOLT_RATIO(7, 29);
        case 7:
        case 9:
                return scale ? SC27XX_VOLT_RATIO(100, 125) :
                        SC27XX_VOLT_RATIO(1, 1);
        case 14:
                return SC27XX_VOLT_RATIO(68, 900);
        case 16:
                return SC27XX_VOLT_RATIO(48, 100);
        case 19:
                return SC27XX_VOLT_RATIO(1, 3);
        default:
                return SC27XX_VOLT_RATIO(1, 1);
        }
        return SC27XX_VOLT_RATIO(1, 1);
}

static int sc2730_adc_get_ratio(int channel, int scale)
{
        switch (channel) {
        case 14:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(68, 900);
                case 1:
                        return SC27XX_VOLT_RATIO(68, 1760);
                case 2:
                        return SC27XX_VOLT_RATIO(68, 2327);
                case 3:
                        return SC27XX_VOLT_RATIO(68, 3654);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        case 15:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(1, 3);
                case 1:
                        return SC27XX_VOLT_RATIO(1000, 5865);
                case 2:
                        return SC27XX_VOLT_RATIO(500, 3879);
                case 3:
                        return SC27XX_VOLT_RATIO(500, 6090);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        case 16:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(48, 100);
                case 1:
                        return SC27XX_VOLT_RATIO(480, 1955);
                case 2:
                        return SC27XX_VOLT_RATIO(480, 2586);
                case 3:
                        return SC27XX_VOLT_RATIO(48, 406);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        case 21:
        case 22:
        case 23:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(3, 8);
                case 1:
                        return SC27XX_VOLT_RATIO(375, 1955);
                case 2:
                        return SC27XX_VOLT_RATIO(375, 2586);
                case 3:
                        return SC27XX_VOLT_RATIO(300, 3248);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        default:
                switch (scale) {
                case 0:
                        return SC27XX_VOLT_RATIO(1, 1);
                case 1:
                        return SC27XX_VOLT_RATIO(1000, 1955);
                case 2:
                        return SC27XX_VOLT_RATIO(1000, 2586);
                case 3:
                        return SC27XX_VOLT_RATIO(1000, 4060);
                default:
                        return SC27XX_VOLT_RATIO(1, 1);
                }
        }
        return SC27XX_VOLT_RATIO(1, 1);
}

static int sc2731_adc_get_ratio(int channel, int scale)
{
        switch (channel) {
        case 1:
        case 2:
        case 3:
        case 4:
                return scale ? SC27XX_VOLT_RATIO(400, 1025) :
                        SC27XX_VOLT_RATIO(1, 1);
        case 5:
                return SC27XX_VOLT_RATIO(7, 29);
        case 6:
                return SC27XX_VOLT_RATIO(375, 9000);
        case 7:
        case 8:
                return scale ? SC27XX_VOLT_RATIO(100, 125) :
                        SC27XX_VOLT_RATIO(1, 1);
        case 19:
                return SC27XX_VOLT_RATIO(1, 3);
        default:
                return SC27XX_VOLT_RATIO(1, 1);
        }
        return SC27XX_VOLT_RATIO(1, 1);
}

/*
 * According to the datasheet set specific value on some channel.
 */
static void sc2720_adc_scale_init(struct sc27xx_adc_data *data)
{
        int i;

        for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
                switch (i) {
                case 5:
                        data->channel_scale[i] = 3;
                        break;
                case 7:
                case 9:
                        data->channel_scale[i] = 2;
                        break;
                case 13:
                        data->channel_scale[i] = 1;
                        break;
                case 19:
                case 30:
                case 31:
                        data->channel_scale[i] = 3;
                        break;
                default:
                        data->channel_scale[i] = 0;
                        break;
                }
        }
}

static void sc2730_adc_scale_init(struct sc27xx_adc_data *data)
{
        int i;

        for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
                switch (i) {
                case 5:
                case 10:
                case 19:
                case 30:
                case 31:
                        data->channel_scale[i] = 3;
                        break;
                case 7:
                case 9:
                        data->channel_scale[i] = 2;
                        break;
                case 13:
                        data->channel_scale[i] = 1;
                        break;
                default:
                        data->channel_scale[i] = 0;
                        break;
                }
        }
}

static void sc2731_adc_scale_init(struct sc27xx_adc_data *data)
{
        int i;
        /*
         * In the current software design, SC2731 support 2 scales,
         * channels 5 uses big scale, others use smale.
         */
        for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
                switch (i) {
                case 5:
                        data->channel_scale[i] = 1;
                        break;
                default:
                        data->channel_scale[i] = 0;
                        break;
                }
        }
}

static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
                           int scale, int *val)
{
        int ret, ret_volref;
        u32 tmp, value, status;

        ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT);
        if (ret) {
                dev_err(data->dev, "timeout to get the hwspinlock\n");
                return ret;
        }

        /*
         * According to the sc2721 chip data sheet, the reference voltage of
         * specific channel 30 and channel 31 in ADC module needs to be set from
         * the default 2.8v to 3.5v.
         */
        if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
                ret = regulator_set_voltage(data->volref,
                                        SC27XX_ADC_REFVOL_VDD35,
                                        SC27XX_ADC_REFVOL_VDD35);
                if (ret) {
                        dev_err(data->dev, "failed to set the volref 3.5v\n");
                        goto unlock_adc;
                }
        }

        ret = regmap_set_bits(data->regmap, data->base + SC27XX_ADC_CTL,
                              SC27XX_ADC_EN);
        if (ret)
                goto regulator_restore;

        ret = regmap_set_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR,
                              SC27XX_ADC_IRQ_CLR);
        if (ret)
                goto disable_adc;

        /* Configure the channel id and scale */
        tmp = (scale << data->var_data->scale_shift) & data->var_data->scale_mask;
        tmp |= channel & SC27XX_ADC_CHN_ID_MASK;
        ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG,
                                 SC27XX_ADC_CHN_ID_MASK |
                                 data->var_data->scale_mask,
                                 tmp);
        if (ret)
                goto disable_adc;

        /* Select 12bit conversion mode, and only sample 1 time */
        tmp = SC27XX_ADC_12BIT_MODE;
        tmp |= (0 << SC27XX_ADC_RUN_NUM_SHIFT) & SC27XX_ADC_RUN_NUM_MASK;
        ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
                                 SC27XX_ADC_RUN_NUM_MASK | SC27XX_ADC_12BIT_MODE,
                                 tmp);
        if (ret)
                goto disable_adc;

        ret = regmap_set_bits(data->regmap, data->base + SC27XX_ADC_CTL,
                              SC27XX_ADC_CHN_RUN);
        if (ret)
                goto disable_adc;

        ret = regmap_read_poll_timeout(data->regmap,
                                       data->base + SC27XX_ADC_INT_RAW,
                                       status, (status & SC27XX_ADC_IRQ_RAW),
                                       SC27XX_ADC_POLL_RAW_STATUS,
                                       SC27XX_ADC_RDY_TIMEOUT);
        if (ret) {
                dev_err(data->dev, "read adc timeout, status = 0x%x\n", status);
                goto disable_adc;
        }

        ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA, &value);
        if (ret)
                goto disable_adc;

        value &= SC27XX_ADC_DATA_MASK;

disable_adc:
        regmap_clear_bits(data->regmap, data->base + SC27XX_ADC_CTL,
                          SC27XX_ADC_EN);
regulator_restore:
        if ((data->var_data->set_volref) && (channel == 30 || channel == 31)) {
                ret_volref = regulator_set_voltage(data->volref,
                                            SC27XX_ADC_REFVOL_VDD28,
                                            SC27XX_ADC_REFVOL_VDD28);
                if (ret_volref) {
                        dev_err(data->dev, "failed to set the volref 2.8v,ret_volref = 0x%x\n",
                                         ret_volref);
                        ret = ret || ret_volref;
                }
        }
unlock_adc:
        hwspin_unlock_raw(data->hwlock);

        if (!ret)
                *val = value;

        return ret;
}

static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data, int channel, int scale,
                                  struct u32_fract *fract)
{
        u32 ratio;

        ratio = data->var_data->get_ratio(channel, scale);
        fract->numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET;
        fract->denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK;
}

static int adc_to_volt(struct sc27xx_adc_linear_graph *graph,
                              int raw_adc)
{
        int tmp;

        tmp = (graph->volt0 - graph->volt1) * (raw_adc - graph->adc1);
        tmp /= (graph->adc0 - graph->adc1);
        tmp += graph->volt1;

        return tmp;
}

static int sc27xx_adc_to_volt(struct sc27xx_adc_linear_graph *graph,
                              int raw_adc)
{
        int tmp;

        tmp = adc_to_volt(graph, raw_adc);

        return tmp < 0 ? 0 : tmp;
}

static int sc27xx_adc_convert_volt(struct sc27xx_adc_data *data, int channel,
                                   int scale, int raw_adc)
{
        struct u32_fract fract;
        u32 volt;

        /*
         * Convert ADC values to voltage values according to the linear graph,
         * and channel 5 and channel 1 has been calibrated, so we can just
         * return the voltage values calculated by the linear graph. But other
         * channels need be calculated to the real voltage values with the
         * voltage ratio.
         */
        switch (channel) {
        case 5:
                return sc27xx_adc_to_volt(&big_scale_graph, raw_adc);

        case 1:
                return sc27xx_adc_to_volt(&small_scale_graph, raw_adc);

        default:
                volt = sc27xx_adc_to_volt(&small_scale_graph, raw_adc);
                break;
        }

        sc27xx_adc_volt_ratio(data, channel, scale, &fract);

        return DIV_ROUND_CLOSEST(volt * fract.denominator, fract.numerator);
}

static int sc27xx_adc_read_processed(struct sc27xx_adc_data *data,
                                     int channel, int scale, int *val)
{
        int ret, raw_adc;

        ret = sc27xx_adc_read(data, channel, scale, &raw_adc);
        if (ret)
                return ret;

        *val = sc27xx_adc_convert_volt(data, channel, scale, raw_adc);
        return 0;
}

static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
                               struct iio_chan_spec const *chan,
                               int *val, int *val2, long mask)
{
        struct sc27xx_adc_data *data = iio_priv(indio_dev);
        int scale = data->channel_scale[chan->channel];
        int ret, tmp;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                mutex_lock(&data->lock);
                ret = sc27xx_adc_read(data, chan->channel, scale, &tmp);
                mutex_unlock(&data->lock);

                if (ret)
                        return ret;

                *val = tmp;
                return IIO_VAL_INT;

        case IIO_CHAN_INFO_PROCESSED:
                mutex_lock(&data->lock);
                ret = sc27xx_adc_read_processed(data, chan->channel, scale,
                                                &tmp);
                mutex_unlock(&data->lock);

                if (ret)
                        return ret;

                *val = tmp;
                return IIO_VAL_INT;

        case IIO_CHAN_INFO_SCALE:
                *val = scale;
                return IIO_VAL_INT;

        default:
                return -EINVAL;
        }
}

static int sc27xx_adc_write_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan,
                                int val, int val2, long mask)
{
        struct sc27xx_adc_data *data = iio_priv(indio_dev);

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                data->channel_scale[chan->channel] = val;
                return IIO_VAL_INT;

        default:
                return -EINVAL;
        }
}

static const struct iio_info sc27xx_info = {
        .read_raw = &sc27xx_adc_read_raw,
        .write_raw = &sc27xx_adc_write_raw,
};

#define SC27XX_ADC_CHANNEL(index, mask) {                       \
        .type = IIO_VOLTAGE,                                    \
        .channel = index,                                       \
        .info_mask_separate = mask | BIT(IIO_CHAN_INFO_SCALE),  \
        .datasheet_name = "CH##index",                          \
        .indexed = 1,                                           \
}

static const struct iio_chan_spec sc27xx_channels[] = {
        SC27XX_ADC_CHANNEL(0, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(1, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(2, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(3, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(4, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(5, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(6, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(7, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(8, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(9, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(10, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(11, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(12, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(13, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(14, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(15, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(16, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(17, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(18, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(19, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(20, BIT(IIO_CHAN_INFO_RAW)),
        SC27XX_ADC_CHANNEL(21, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(22, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(23, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(24, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(25, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(26, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(27, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(28, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(29, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(30, BIT(IIO_CHAN_INFO_PROCESSED)),
        SC27XX_ADC_CHANNEL(31, BIT(IIO_CHAN_INFO_PROCESSED)),
};

static int sc27xx_adc_enable(struct sc27xx_adc_data *data)
{
        int ret;

        ret = regmap_set_bits(data->regmap, data->var_data->module_en,
                              SC27XX_MODULE_ADC_EN);
        if (ret)
                return ret;

        /* Enable ADC work clock and controller clock */
        ret = regmap_set_bits(data->regmap, data->var_data->clk_en,
                              SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);
        if (ret)
                goto disable_adc;

        /* ADC channel scales' calibration from nvmem device */
        ret = sc27xx_adc_scale_calibration(data, true);
        if (ret)
                goto disable_clk;

        ret = sc27xx_adc_scale_calibration(data, false);
        if (ret)
                goto disable_clk;

        return 0;

disable_clk:
        regmap_clear_bits(data->regmap, data->var_data->clk_en,
                          SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);
disable_adc:
        regmap_clear_bits(data->regmap, data->var_data->module_en,
                          SC27XX_MODULE_ADC_EN);

        return ret;
}

static void sc27xx_adc_disable(void *_data)
{
        struct sc27xx_adc_data *data = _data;

        /* Disable ADC work clock and controller clock */
        regmap_clear_bits(data->regmap, data->var_data->clk_en,
                          SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);

        regmap_clear_bits(data->regmap, data->var_data->module_en,
                          SC27XX_MODULE_ADC_EN);
}

static const struct sc27xx_adc_variant_data sc2731_data = {
        .module_en = SC2731_MODULE_EN,
        .clk_en = SC2731_ARM_CLK_EN,
        .scale_shift = SC27XX_ADC_SCALE_SHIFT,
        .scale_mask = SC27XX_ADC_SCALE_MASK,
        .bscale_cal = &sc2731_big_scale_graph_calib,
        .sscale_cal = &sc2731_small_scale_graph_calib,
        .init_scale = sc2731_adc_scale_init,
        .get_ratio = sc2731_adc_get_ratio,
        .set_volref = false,
};

static const struct sc27xx_adc_variant_data sc2730_data = {
        .module_en = SC2730_MODULE_EN,
        .clk_en = SC2730_ARM_CLK_EN,
        .scale_shift = SC27XX_ADC_SCALE_SHIFT,
        .scale_mask = SC27XX_ADC_SCALE_MASK,
        .bscale_cal = &big_scale_graph_calib,
        .sscale_cal = &small_scale_graph_calib,
        .init_scale = sc2730_adc_scale_init,
        .get_ratio = sc2730_adc_get_ratio,
        .set_volref = false,
};

static const struct sc27xx_adc_variant_data sc2721_data = {
        .module_en = SC2731_MODULE_EN,
        .clk_en = SC2721_ARM_CLK_EN,
        .scale_shift = SC2721_ADC_SCALE_SHIFT,
        .scale_mask = SC2721_ADC_SCALE_MASK,
        .bscale_cal = &sc2731_big_scale_graph_calib,
        .sscale_cal = &sc2731_small_scale_graph_calib,
        .init_scale = sc2731_adc_scale_init,
        .get_ratio = sc2721_adc_get_ratio,
        .set_volref = true,
};

static const struct sc27xx_adc_variant_data sc2720_data = {
        .module_en = SC2731_MODULE_EN,
        .clk_en = SC2721_ARM_CLK_EN,
        .scale_shift = SC27XX_ADC_SCALE_SHIFT,
        .scale_mask = SC27XX_ADC_SCALE_MASK,
        .bscale_cal = &big_scale_graph_calib,
        .sscale_cal = &small_scale_graph_calib,
        .init_scale = sc2720_adc_scale_init,
        .get_ratio = sc2720_adc_get_ratio,
        .set_volref = false,
};

static int sc27xx_adc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        struct sc27xx_adc_data *sc27xx_data;
        const struct sc27xx_adc_variant_data *pdata;
        struct iio_dev *indio_dev;
        int ret;

        pdata = of_device_get_match_data(dev);
        if (!pdata)
                return dev_err_probe(dev, -EINVAL, "No matching driver data found\n");

        indio_dev = devm_iio_device_alloc(dev, sizeof(*sc27xx_data));
        if (!indio_dev)
                return -ENOMEM;

        sc27xx_data = iio_priv(indio_dev);

        sc27xx_data->regmap = dev_get_regmap(dev->parent, NULL);
        if (!sc27xx_data->regmap)
                return dev_err_probe(dev, -ENODEV, "failed to get ADC regmap\n");

        ret = of_property_read_u32(np, "reg", &sc27xx_data->base);
        if (ret)
                return dev_err_probe(dev, ret, "failed to get ADC base address\n");

        sc27xx_data->irq = platform_get_irq(pdev, 0);
        if (sc27xx_data->irq < 0)
                return sc27xx_data->irq;

        ret = of_hwspin_lock_get_id(np, 0);
        if (ret < 0)
                return dev_err_probe(dev, ret, "failed to get hwspinlock id\n");

        sc27xx_data->hwlock = devm_hwspin_lock_request_specific(dev, ret);
        if (!sc27xx_data->hwlock)
                return dev_err_probe(dev, -ENXIO, "failed to request hwspinlock\n");

        sc27xx_data->dev = dev;
        if (pdata->set_volref) {
                sc27xx_data->volref = devm_regulator_get(dev, "vref");
                if (IS_ERR(sc27xx_data->volref))
                        return dev_err_probe(dev, PTR_ERR(sc27xx_data->volref),
                                             "failed to get ADC volref\n");
        }

        sc27xx_data->var_data = pdata;
        sc27xx_data->var_data->init_scale(sc27xx_data);

        ret = sc27xx_adc_enable(sc27xx_data);
        if (ret)
                return dev_err_probe(dev, ret, "failed to enable ADC module\n");

        ret = devm_add_action_or_reset(dev, sc27xx_adc_disable, sc27xx_data);
        if (ret)
                return dev_err_probe(dev, ret, "failed to add ADC disable action\n");

        indio_dev->name = dev_name(dev);
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->info = &sc27xx_info;
        indio_dev->channels = sc27xx_channels;
        indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels);

        mutex_init(&sc27xx_data->lock);

        ret = devm_iio_device_register(dev, indio_dev);
        if (ret)
                dev_err(dev, "could not register iio (ADC)");

        return ret;
}

static const struct of_device_id sc27xx_adc_of_match[] = {
        { .compatible = "sprd,sc2731-adc", .data = &sc2731_data},
        { .compatible = "sprd,sc2730-adc", .data = &sc2730_data},
        { .compatible = "sprd,sc2721-adc", .data = &sc2721_data},
        { .compatible = "sprd,sc2720-adc", .data = &sc2720_data},
        { }
};
MODULE_DEVICE_TABLE(of, sc27xx_adc_of_match);

static struct platform_driver sc27xx_adc_driver = {
        .probe = sc27xx_adc_probe,
        .driver = {
                .name = "sc27xx-adc",
                .of_match_table = sc27xx_adc_of_match,
        },
};

module_platform_driver(sc27xx_adc_driver);

MODULE_AUTHOR("Freeman Liu <freeman.liu@spreadtrum.com>");
MODULE_DESCRIPTION("Spreadtrum SC27XX ADC Driver");
MODULE_LICENSE("GPL v2");