// SPDX-License-Identifier: GPL-2.0-only
/*
 * IIO driver for the MiraMEMS DA311 3-axis accelerometer
 *
 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
 * Copyright (c) 2011-2013 MiraMEMS Sensing Technology Co., Ltd.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/byteorder/generic.h>

#define DA311_CHIP_ID                   0x13

/*
 * Note register addressed go from 0 - 0x3f and then wrap.
 * For some reason there are 2 banks with 0 - 0x3f addresses,
 * rather then a single 0-0x7f bank.
 */

/* Bank 0 regs */
#define DA311_REG_BANK                  0x0000
#define DA311_REG_LDO_REG               0x0006
#define DA311_REG_CHIP_ID               0x000f
#define DA311_REG_TEMP_CFG_REG          0x001f
#define DA311_REG_CTRL_REG1             0x0020
#define DA311_REG_CTRL_REG3             0x0022
#define DA311_REG_CTRL_REG4             0x0023
#define DA311_REG_CTRL_REG5             0x0024
#define DA311_REG_CTRL_REG6             0x0025
#define DA311_REG_STATUS_REG            0x0027
#define DA311_REG_OUT_X_L               0x0028
#define DA311_REG_OUT_X_H               0x0029
#define DA311_REG_OUT_Y_L               0x002a
#define DA311_REG_OUT_Y_H               0x002b
#define DA311_REG_OUT_Z_L               0x002c
#define DA311_REG_OUT_Z_H               0x002d
#define DA311_REG_INT1_CFG              0x0030
#define DA311_REG_INT1_SRC              0x0031
#define DA311_REG_INT1_THS              0x0032
#define DA311_REG_INT1_DURATION         0x0033
#define DA311_REG_INT2_CFG              0x0034
#define DA311_REG_INT2_SRC              0x0035
#define DA311_REG_INT2_THS              0x0036
#define DA311_REG_INT2_DURATION         0x0037
#define DA311_REG_CLICK_CFG             0x0038
#define DA311_REG_CLICK_SRC             0x0039
#define DA311_REG_CLICK_THS             0x003a
#define DA311_REG_TIME_LIMIT            0x003b
#define DA311_REG_TIME_LATENCY          0x003c
#define DA311_REG_TIME_WINDOW           0x003d

/* Bank 1 regs */
#define DA311_REG_SOFT_RESET            0x0105
#define DA311_REG_OTP_XOFF_L            0x0110
#define DA311_REG_OTP_XOFF_H            0x0111
#define DA311_REG_OTP_YOFF_L            0x0112
#define DA311_REG_OTP_YOFF_H            0x0113
#define DA311_REG_OTP_ZOFF_L            0x0114
#define DA311_REG_OTP_ZOFF_H            0x0115
#define DA311_REG_OTP_XSO               0x0116
#define DA311_REG_OTP_YSO               0x0117
#define DA311_REG_OTP_ZSO               0x0118
#define DA311_REG_OTP_TRIM_OSC          0x011b
#define DA311_REG_LPF_ABSOLUTE          0x011c
#define DA311_REG_TEMP_OFF1             0x0127
#define DA311_REG_TEMP_OFF2             0x0128
#define DA311_REG_TEMP_OFF3             0x0129
#define DA311_REG_OTP_TRIM_THERM_H      0x011a

/*
 * a value of + or -1024 corresponds to + or - 1G
 * scale = 9.81 / 1024 = 0.009580078
 */

static const int da311_nscale = 9580078;

#define DA311_CHANNEL(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),   \
}

static const struct iio_chan_spec da311_channels[] = {
        /* | 0x80 comes from the android driver */
        DA311_CHANNEL(DA311_REG_OUT_X_L | 0x80, X),
        DA311_CHANNEL(DA311_REG_OUT_Y_L | 0x80, Y),
        DA311_CHANNEL(DA311_REG_OUT_Z_L | 0x80, Z),
};

struct da311_data {
        struct i2c_client *client;
};

static int da311_register_mask_write(struct i2c_client *client, u16 addr,
                                     u8 mask, u8 data)
{
        int ret;
        u8 tmp_data = 0;

        if (addr & 0xff00) {
                /* Select bank 1 */
                ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x01);
                if (ret < 0)
                        return ret;
        }

        if (mask != 0xff) {
                ret = i2c_smbus_read_byte_data(client, addr);
                if (ret < 0)
                        return ret;
                tmp_data = ret;
        }

        tmp_data &= ~mask;
        tmp_data |= data & mask;
        ret = i2c_smbus_write_byte_data(client, addr & 0xff, tmp_data);
        if (ret < 0)
                return ret;

        if (addr & 0xff00) {
                /* Back to bank 0 */
                ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x00);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

/* Init sequence taken from the android driver */
static int da311_reset(struct i2c_client *client)
{
        static const struct {
                u16 addr;
                u8 mask;
                u8 data;
        } init_data[] = {
                { DA311_REG_TEMP_CFG_REG,       0xff,   0x08 },
                { DA311_REG_CTRL_REG5,          0xff,   0x80 },
                { DA311_REG_CTRL_REG4,          0x30,   0x00 },
                { DA311_REG_CTRL_REG1,          0xff,   0x6f },
                { DA311_REG_TEMP_CFG_REG,       0xff,   0x88 },
                { DA311_REG_LDO_REG,            0xff,   0x02 },
                { DA311_REG_OTP_TRIM_OSC,       0xff,   0x27 },
                { DA311_REG_LPF_ABSOLUTE,       0xff,   0x30 },
                { DA311_REG_TEMP_OFF1,          0xff,   0x3f },
                { DA311_REG_TEMP_OFF2,          0xff,   0xff },
                { DA311_REG_TEMP_OFF3,          0xff,   0x0f },
        };
        int i, ret;

        /* Reset */
        ret = da311_register_mask_write(client, DA311_REG_SOFT_RESET,
                                        0xff, 0xaa);
        if (ret < 0)
                return ret;

        for (i = 0; i < ARRAY_SIZE(init_data); i++) {
                ret = da311_register_mask_write(client,
                                                init_data[i].addr,
                                                init_data[i].mask,
                                                init_data[i].data);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int da311_enable(struct i2c_client *client, bool enable)
{
        u8 data = enable ? 0x00 : 0x20;

        return da311_register_mask_write(client, DA311_REG_TEMP_CFG_REG,
                                         0x20, data);
}

static int da311_read_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan,
                                int *val, int *val2, long mask)
{
        struct da311_data *data = iio_priv(indio_dev);
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                ret = i2c_smbus_read_word_data(data->client, chan->address);
                if (ret < 0)
                        return ret;
                /*
                 * Values are 12 bits, stored as 16 bits with the 4
                 * least significant bits always 0.
                 */
                *val = (short)ret >> 4;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                *val = 0;
                *val2 = da311_nscale;
                return IIO_VAL_INT_PLUS_NANO;
        default:
                return -EINVAL;
        }
}

static const struct iio_info da311_info = {
        .read_raw       = da311_read_raw,
};

static void da311_disable(void *client)
{
        da311_enable(client, false);
}

static int da311_probe(struct i2c_client *client)
{
        int ret;
        struct iio_dev *indio_dev;
        struct da311_data *data;

        ret = i2c_smbus_read_byte_data(client, DA311_REG_CHIP_ID);
        if (ret != DA311_CHIP_ID)
                return (ret < 0) ? ret : -ENODEV;

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

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

        indio_dev->info = &da311_info;
        indio_dev->name = "da311";
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = da311_channels;
        indio_dev->num_channels = ARRAY_SIZE(da311_channels);

        ret = da311_reset(client);
        if (ret < 0)
                return ret;

        ret = da311_enable(client, true);
        if (ret < 0)
                return ret;

        ret = devm_add_action_or_reset(&client->dev, da311_disable, client);
        if (ret)
                return ret;

        return devm_iio_device_register(&client->dev, indio_dev);
}

static int da311_suspend(struct device *dev)
{
        return da311_enable(to_i2c_client(dev), false);
}

static int da311_resume(struct device *dev)
{
        return da311_enable(to_i2c_client(dev), true);
}

static DEFINE_SIMPLE_DEV_PM_OPS(da311_pm_ops, da311_suspend, da311_resume);

static const struct i2c_device_id da311_i2c_id[] = {
        { "da311" },
        { }
};
MODULE_DEVICE_TABLE(i2c, da311_i2c_id);

static struct i2c_driver da311_driver = {
        .driver = {
                .name = "da311",
                .pm = pm_sleep_ptr(&da311_pm_ops),
        },
        .probe          = da311_probe,
        .id_table       = da311_i2c_id,
};

module_i2c_driver(da311_driver);

MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("MiraMEMS DA311 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");