// SPDX-License-Identifier: GPL-2.0-only
/*
 * BMA220 Digital triaxial acceleration sensor driver
 *
 * Copyright (c) 2016,2020 Intel Corporation.
 * Copyright (c) 2025 Petre Rodan  <petre.rodan@subdimension.ro>
 */

#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/types.h>

#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>

#include "bma220.h"

#define BMA220_REG_ID                           0x00
#define BMA220_REG_REVISION_ID                  0x01
#define BMA220_REG_ACCEL_X                      0x02
#define BMA220_REG_ACCEL_Y                      0x03
#define BMA220_REG_ACCEL_Z                      0x04
#define BMA220_REG_CONF0                        0x05
#define BMA220_HIGH_DUR_MSK                     GENMASK(5, 0)
#define BMA220_HIGH_HY_MSK                      GENMASK(7, 6)
#define BMA220_REG_CONF1                        0x06
#define BMA220_HIGH_TH_MSK                      GENMASK(3, 0)
#define BMA220_LOW_TH_MSK                       GENMASK(7, 4)
#define BMA220_REG_CONF2                        0x07
#define BMA220_LOW_DUR_MSK                      GENMASK(5, 0)
#define BMA220_LOW_HY_MSK                       GENMASK(7, 6)
#define BMA220_REG_CONF3                        0x08
#define BMA220_TT_DUR_MSK                       GENMASK(2, 0)
#define BMA220_TT_TH_MSK                        GENMASK(6, 3)
#define BMA220_REG_CONF4                        0x09
#define BMA220_SLOPE_DUR_MSK                    GENMASK(1, 0)
#define BMA220_SLOPE_TH_MSK                     GENMASK(5, 2)
#define BMA220_REG_CONF5                        0x0a
#define BMA220_TIP_EN_MSK                       BIT(4)
#define BMA220_REG_IF0                          0x0b
#define BMA220_REG_IF1                          0x0c
#define BMA220_IF_SLOPE                         BIT(0)
#define BMA220_IF_DRDY                          BIT(1)
#define BMA220_IF_HIGH                          BIT(2)
#define BMA220_IF_LOW                           BIT(3)
#define BMA220_IF_TT                            BIT(4)
#define BMA220_REG_IE0                          0x0d
#define BMA220_INT_EN_TAP_Z_MSK                 BIT(0)
#define BMA220_INT_EN_TAP_Y_MSK                 BIT(1)
#define BMA220_INT_EN_TAP_X_MSK                 BIT(2)
#define BMA220_INT_EN_SLOPE_Z_MSK               BIT(3)
#define BMA220_INT_EN_SLOPE_Y_MSK               BIT(4)
#define BMA220_INT_EN_SLOPE_X_MSK               BIT(5)
#define BMA220_INT_EN_DRDY_MSK                  BIT(7)
#define BMA220_REG_IE1                          0x0e
#define BMA220_INT_EN_HIGH_Z_MSK                BIT(0)
#define BMA220_INT_EN_HIGH_Y_MSK                BIT(1)
#define BMA220_INT_EN_HIGH_X_MSK                BIT(2)
#define BMA220_INT_EN_LOW_MSK                   BIT(3)
#define BMA220_INT_LATCH_MSK                    GENMASK(6, 4)
#define BMA220_INT_RST_MSK                      BIT(7)
#define BMA220_REG_IE2                          0x0f
#define BMA220_REG_FILTER                       0x10
#define BMA220_FILTER_MASK                      GENMASK(3, 0)
#define BMA220_REG_RANGE                        0x11
#define BMA220_RANGE_MASK                       GENMASK(1, 0)
#define BMA220_REG_SUSPEND                      0x18
#define BMA220_REG_SOFTRESET                    0x19

#define BMA220_CHIP_ID                          0xDD
#define BMA220_SUSPEND_SLEEP                    0xFF
#define BMA220_SUSPEND_WAKE                     0x00
#define BMA220_RESET_MODE                       0xFF
#define BMA220_NONRESET_MODE                    0x00

#define BMA220_DEVICE_NAME                      "bma220"

#define BMA220_COF_1000Hz                       0x0
#define BMA220_COF_500Hz                        0x1
#define BMA220_COF_250Hz                        0x2
#define BMA220_COF_125Hz                        0x3
#define BMA220_COF_64Hz                         0x4
#define BMA220_COF_32Hz                         0x5

#define BMA220_ACCEL_CHANNEL(index, reg, axis) {                        \
        .type = IIO_ACCEL,                                              \
        .address = reg,                                                 \
        .modified = 1,                                                  \
        .channel2 = IIO_MOD_##axis,                                     \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
            BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),           \
        .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE) |\
            BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),           \
        .scan_index = index,                                            \
        .scan_type = {                                                  \
                .sign = 's',                                            \
                .realbits = 6,                                          \
                .storagebits = 8,                                       \
                .shift = 2,                                             \
                .endianness = IIO_CPU,                                  \
        },                                                              \
}

enum bma220_axis {
        AXIS_X,
        AXIS_Y,
        AXIS_Z,
};

static const int bma220_scale_table[][2] = {
        { 0, 623000 }, { 1, 248000 }, { 2, 491000 }, { 4, 983000 },
};

struct bma220_data {
        struct regmap *regmap;
        struct mutex lock;
        u8 lpf_3dB_freq_idx;
        u8 range_idx;
        struct iio_trigger *trig;
        struct {
                s8 chans[3];
                /* Ensure timestamp is naturally aligned. */
                aligned_s64 timestamp;
        } scan __aligned(IIO_DMA_MINALIGN);
};

static const struct iio_chan_spec bma220_channels[] = {
        BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
        BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
        BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
        IIO_CHAN_SOFT_TIMESTAMP(3),
};

/* Available cut-off frequencies of the low pass filter in Hz. */
static const int bma220_lpf_3dB_freq_Hz_table[] = {
        [BMA220_COF_1000Hz] = 1000,
        [BMA220_COF_500Hz] = 500,
        [BMA220_COF_250Hz] = 250,
        [BMA220_COF_125Hz] = 125,
        [BMA220_COF_64Hz] = 64,
        [BMA220_COF_32Hz] = 32,
};

static const unsigned long bma220_accel_scan_masks[] = {
        BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
        0
};

static bool bma220_is_writable_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case BMA220_REG_CONF0:
        case BMA220_REG_CONF1:
        case BMA220_REG_CONF2:
        case BMA220_REG_CONF3:
        case BMA220_REG_CONF4:
        case BMA220_REG_CONF5:
        case BMA220_REG_IE0:
        case BMA220_REG_IE1:
        case BMA220_REG_IE2:
        case BMA220_REG_FILTER:
        case BMA220_REG_RANGE:
        case BMA220_REG_WDT:
                return true;
        default:
                return false;
        }
}

const struct regmap_config bma220_spi_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .read_flag_mask = BIT(7),
        .max_register = BMA220_REG_SOFTRESET,
        .cache_type = REGCACHE_NONE,
        .writeable_reg = bma220_is_writable_reg,
};
EXPORT_SYMBOL_NS_GPL(bma220_spi_regmap_config, "IIO_BOSCH_BMA220");

/*
 * Based on the datasheet the memory map differs between the SPI and the I2C
 * implementations. I2C register addresses are simply shifted to the left
 * by 1 bit yet the register size remains unchanged.
 * This driver employs the SPI memory map to correlate register names to
 * addresses regardless of the bus type.
 */

const struct regmap_config bma220_i2c_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .reg_shift = -1,
        .max_register = BMA220_REG_SOFTRESET,
        .cache_type = REGCACHE_NONE,
        .writeable_reg = bma220_is_writable_reg,
};
EXPORT_SYMBOL_NS_GPL(bma220_i2c_regmap_config, "IIO_BOSCH_BMA220");

static int bma220_data_rdy_trigger_set_state(struct iio_trigger *trig,
                                             bool state)
{
        struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
        struct bma220_data *data = iio_priv(indio_dev);

        return regmap_update_bits(data->regmap, BMA220_REG_IE0,
                                  BMA220_INT_EN_DRDY_MSK,
                                  FIELD_PREP(BMA220_INT_EN_DRDY_MSK, state));
}

static const struct iio_trigger_ops bma220_trigger_ops = {
        .set_trigger_state = &bma220_data_rdy_trigger_set_state,
        .validate_device = &iio_trigger_validate_own_device,
};

static irqreturn_t bma220_trigger_handler(int irq, void *p)
{
        int ret;
        struct iio_poll_func *pf = p;
        struct iio_dev *indio_dev = pf->indio_dev;
        struct bma220_data *data = iio_priv(indio_dev);

        ret = regmap_bulk_read(data->regmap, BMA220_REG_ACCEL_X,
                               &data->scan.chans,
                               sizeof(data->scan.chans));
        if (ret < 0)
                return IRQ_NONE;

        iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan),
                                    iio_get_time_ns(indio_dev));
        iio_trigger_notify_done(indio_dev->trig);

        return IRQ_HANDLED;
}

static int bma220_read_raw(struct iio_dev *indio_dev,
                           struct iio_chan_spec const *chan,
                           int *val, int *val2, long mask)
{
        int ret;
        u8 index;
        unsigned int reg;
        struct bma220_data *data = iio_priv(indio_dev);

        guard(mutex)(&data->lock);

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                ret = regmap_read(data->regmap, chan->address, &reg);
                if (ret < 0)
                        return -EINVAL;
                *val = sign_extend32(reg >> chan->scan_type.shift,
                                     chan->scan_type.realbits - 1);
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                index = data->range_idx;
                *val = bma220_scale_table[index][0];
                *val2 = bma220_scale_table[index][1];
                return IIO_VAL_INT_PLUS_MICRO;
        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
                index = data->lpf_3dB_freq_idx;
                *val = bma220_lpf_3dB_freq_Hz_table[index];
                return IIO_VAL_INT;
        }

        return -EINVAL;
}

static int bma220_find_match_2dt(const int (*tbl)[2], const int n,
                                 const int val, const int val2)
{
        int i;

        for (i = 0; i < n; i++) {
                if (tbl[i][0] == val && tbl[i][1] == val2)
                        return i;
        }

        return -EINVAL;
}

static int bma220_find_match(const int *arr, const int n, const int val)
{
        int i;

        for (i = 0; i < n; i++) {
                if (arr[i] == val)
                        return i;
        }

        return -EINVAL;
}

static int bma220_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int val, int val2, long mask)
{
        int ret;
        int index = -1;
        struct bma220_data *data = iio_priv(indio_dev);

        guard(mutex)(&data->lock);

        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                index = bma220_find_match_2dt(bma220_scale_table,
                                              ARRAY_SIZE(bma220_scale_table),
                                              val, val2);
                if (index < 0)
                        return -EINVAL;

                ret = regmap_update_bits(data->regmap, BMA220_REG_RANGE,
                                         BMA220_RANGE_MASK,
                                         FIELD_PREP(BMA220_RANGE_MASK, index));
                if (ret < 0)
                        return ret;
                data->range_idx = index;

                return 0;
        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
                index = bma220_find_match(bma220_lpf_3dB_freq_Hz_table,
                                          ARRAY_SIZE(bma220_lpf_3dB_freq_Hz_table),
                                          val);
                if (index < 0)
                        return -EINVAL;

                ret = regmap_update_bits(data->regmap, BMA220_REG_FILTER,
                                         BMA220_FILTER_MASK,
                                         FIELD_PREP(BMA220_FILTER_MASK, index));
                if (ret < 0)
                        return ret;
                data->lpf_3dB_freq_idx = index;

                return 0;
        }

        return -EINVAL;
}

static int bma220_read_avail(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             const int **vals, int *type, int *length,
                             long mask)
{
        switch (mask) {
        case IIO_CHAN_INFO_SCALE:
                *vals = (int *)bma220_scale_table;
                *type = IIO_VAL_INT_PLUS_MICRO;
                *length = ARRAY_SIZE(bma220_scale_table) * 2;
                return IIO_AVAIL_LIST;
        case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
                *vals = (const int *)bma220_lpf_3dB_freq_Hz_table;
                *type = IIO_VAL_INT;
                *length = ARRAY_SIZE(bma220_lpf_3dB_freq_Hz_table);
                return IIO_AVAIL_LIST;
        default:
                return -EINVAL;
        }
}

static int bma220_reg_access(struct iio_dev *indio_dev, unsigned int reg,
                             unsigned int writeval, unsigned int *readval)
{
        struct bma220_data *data = iio_priv(indio_dev);

        if (readval)
                return regmap_read(data->regmap, reg, readval);
        return regmap_write(data->regmap, reg, writeval);
}

static const struct iio_info bma220_info = {
        .read_raw               = bma220_read_raw,
        .write_raw              = bma220_write_raw,
        .read_avail             = bma220_read_avail,
        .debugfs_reg_access     = &bma220_reg_access,
};

static int bma220_reset(struct bma220_data *data, bool up)
{
        int ret;
        unsigned int i, val;

        /*
         * The chip can be reset by a simple register read.
         * We need up to 2 register reads of the softreset register
         * to make sure that the device is in the desired state.
         */
        for (i = 0; i < 2; i++) {
                ret = regmap_read(data->regmap, BMA220_REG_SOFTRESET, &val);
                if (ret < 0)
                        return ret;

                if (up && val == BMA220_RESET_MODE)
                        return 0;

                if (!up && val == BMA220_NONRESET_MODE)
                        return 0;
        }

        return -EBUSY;
}

static int bma220_power(struct bma220_data *data, bool up)
{
        int ret;
        unsigned int i, val;

        /*
         * The chip can be suspended/woken up by a simple register read.
         * So, we need up to 2 register reads of the suspend register
         * to make sure that the device is in the desired state.
         */
        for (i = 0; i < 2; i++) {
                ret = regmap_read(data->regmap, BMA220_REG_SUSPEND, &val);
                if (ret < 0)
                        return ret;

                if (up && val == BMA220_SUSPEND_SLEEP)
                        return 0;

                if (!up && val == BMA220_SUSPEND_WAKE)
                        return 0;
        }

        return -EBUSY;
}

static int bma220_init(struct device *dev, struct bma220_data *data)
{
        int ret;
        unsigned int val;
        static const char * const regulator_names[] = { "vddd", "vddio", "vdda" };

        ret = devm_regulator_bulk_get_enable(dev,
                                             ARRAY_SIZE(regulator_names),
                                             regulator_names);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to get regulators\n");

        ret = regmap_read(data->regmap, BMA220_REG_ID, &val);
        if (ret)
                return dev_err_probe(dev, ret,
                                     "Failed to read chip id register\n");

        if (val != BMA220_CHIP_ID)
                dev_info(dev, "Unknown chip found: 0x%02x\n", val);

        ret = bma220_power(data, true);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to power-on chip\n");

        ret = bma220_reset(data, true);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to soft reset chip\n");

        return 0;
}

static void bma220_deinit(void *data_ptr)
{
        struct bma220_data *data = data_ptr;
        int ret;
        struct device *dev = regmap_get_device(data->regmap);

        ret = bma220_power(data, false);
        if (ret)
                dev_warn(dev,
                         "Failed to put device into suspend mode (%pe)\n",
                         ERR_PTR(ret));
}

static irqreturn_t bma220_irq_handler(int irq, void *private)
{
        struct iio_dev *indio_dev = private;
        struct bma220_data *data = iio_priv(indio_dev);
        int ret;
        unsigned int bma220_reg_if1;

        ret = regmap_read(data->regmap, BMA220_REG_IF1, &bma220_reg_if1);
        if (ret)
                return IRQ_NONE;

        if (FIELD_GET(BMA220_IF_DRDY, bma220_reg_if1))
                iio_trigger_poll_nested(data->trig);

        return IRQ_HANDLED;
}

int bma220_common_probe(struct device *dev, struct regmap *regmap, int irq)
{
        int ret;
        struct iio_dev *indio_dev;
        struct bma220_data *data;

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

        data = iio_priv(indio_dev);
        data->regmap = regmap;

        ret = bma220_init(dev, data);
        if (ret)
                return ret;

        ret = devm_mutex_init(dev, &data->lock);
        if (ret)
                return ret;

        indio_dev->info = &bma220_info;
        indio_dev->name = BMA220_DEVICE_NAME;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = bma220_channels;
        indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
        indio_dev->available_scan_masks = bma220_accel_scan_masks;

        if (irq > 0) {
                data->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
                                                    indio_dev->name,
                                                    iio_device_id(indio_dev));
                if (!data->trig)
                        return -ENOMEM;

                data->trig->ops = &bma220_trigger_ops;
                iio_trigger_set_drvdata(data->trig, indio_dev);

                ret = devm_iio_trigger_register(dev, data->trig);
                if (ret)
                        return dev_err_probe(dev, ret,
                                             "iio trigger register fail\n");
                indio_dev->trig = iio_trigger_get(data->trig);
                ret = devm_request_threaded_irq(dev, irq, NULL,
                                                &bma220_irq_handler, IRQF_ONESHOT,
                                                indio_dev->name, indio_dev);
                if (ret)
                        return dev_err_probe(dev, ret,
                                             "request irq %d failed\n", irq);
        }

        ret = devm_add_action_or_reset(dev, bma220_deinit, data);
        if (ret)
                return ret;

        ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
                                              bma220_trigger_handler, NULL);
        if (ret < 0)
                dev_err_probe(dev, ret, "iio triggered buffer setup failed\n");

        return devm_iio_device_register(dev, indio_dev);
}
EXPORT_SYMBOL_NS_GPL(bma220_common_probe, "IIO_BOSCH_BMA220");

static int bma220_suspend(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct bma220_data *data = iio_priv(indio_dev);

        return bma220_power(data, false);
}

static int bma220_resume(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct bma220_data *data = iio_priv(indio_dev);

        return bma220_power(data, true);
}
EXPORT_NS_SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume,
                            IIO_BOSCH_BMA220);

MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
MODULE_LICENSE("GPL");