// SPDX-License-Identifier: GPL-2.0-only
/*
 * STMicroelectronics sensors core library driver
 *
 * Copyright 2012-2013 STMicroelectronics Inc.
 *
 * Denis Ciocca <denis.ciocca@st.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/mutex.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/regmap.h>
#include <linux/unaligned.h>
#include <linux/iio/common/st_sensors.h>

#include "st_sensors_core.h"

int st_sensors_write_data_with_mask(struct iio_dev *indio_dev,
                                    u8 reg_addr, u8 mask, u8 data)
{
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        return regmap_update_bits(sdata->regmap,
                                  reg_addr, mask, data << __ffs(mask));
}

int st_sensors_debugfs_reg_access(struct iio_dev *indio_dev,
                                  unsigned reg, unsigned writeval,
                                  unsigned *readval)
{
        struct st_sensor_data *sdata = iio_priv(indio_dev);
        int err;

        if (!readval)
                return regmap_write(sdata->regmap, reg, writeval);

        err = regmap_read(sdata->regmap, reg, readval);
        if (err < 0)
                return err;

        return 0;
}
EXPORT_SYMBOL_NS(st_sensors_debugfs_reg_access, "IIO_ST_SENSORS");

static int st_sensors_match_odr(struct st_sensor_settings *sensor_settings,
                        unsigned int odr, struct st_sensor_odr_avl *odr_out)
{
        int i, ret = -EINVAL;

        for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
                if (sensor_settings->odr.odr_avl[i].hz == 0)
                        goto st_sensors_match_odr_error;

                if (sensor_settings->odr.odr_avl[i].hz == odr) {
                        odr_out->hz = sensor_settings->odr.odr_avl[i].hz;
                        odr_out->value = sensor_settings->odr.odr_avl[i].value;
                        ret = 0;
                        break;
                }
        }

st_sensors_match_odr_error:
        return ret;
}

int st_sensors_set_odr(struct iio_dev *indio_dev, unsigned int odr)
{
        int err = 0;
        struct st_sensor_odr_avl odr_out = {0, 0};
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        mutex_lock(&sdata->odr_lock);

        if (!sdata->sensor_settings->odr.mask)
                goto unlock_mutex;

        err = st_sensors_match_odr(sdata->sensor_settings, odr, &odr_out);
        if (err < 0)
                goto unlock_mutex;

        if ((sdata->sensor_settings->odr.addr ==
                                        sdata->sensor_settings->pw.addr) &&
                                (sdata->sensor_settings->odr.mask ==
                                        sdata->sensor_settings->pw.mask)) {
                if (sdata->enabled == true) {
                        err = st_sensors_write_data_with_mask(indio_dev,
                                sdata->sensor_settings->odr.addr,
                                sdata->sensor_settings->odr.mask,
                                odr_out.value);
                } else {
                        err = 0;
                }
        } else {
                err = st_sensors_write_data_with_mask(indio_dev,
                        sdata->sensor_settings->odr.addr,
                        sdata->sensor_settings->odr.mask,
                        odr_out.value);
        }
        if (err >= 0)
                sdata->odr = odr_out.hz;

unlock_mutex:
        mutex_unlock(&sdata->odr_lock);

        return err;
}
EXPORT_SYMBOL_NS(st_sensors_set_odr, "IIO_ST_SENSORS");

static int st_sensors_match_fs(struct st_sensor_settings *sensor_settings,
                                        unsigned int fs, int *index_fs_avl)
{
        int i, ret = -EINVAL;

        for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
                if (sensor_settings->fs.fs_avl[i].num == 0)
                        return ret;

                if (sensor_settings->fs.fs_avl[i].num == fs) {
                        *index_fs_avl = i;
                        ret = 0;
                        break;
                }
        }

        return ret;
}

static int st_sensors_set_fullscale(struct iio_dev *indio_dev, unsigned int fs)
{
        int err, i = 0;
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        if (sdata->sensor_settings->fs.addr == 0)
                return 0;

        err = st_sensors_match_fs(sdata->sensor_settings, fs, &i);
        if (err < 0)
                goto st_accel_set_fullscale_error;

        err = st_sensors_write_data_with_mask(indio_dev,
                                sdata->sensor_settings->fs.addr,
                                sdata->sensor_settings->fs.mask,
                                sdata->sensor_settings->fs.fs_avl[i].value);
        if (err < 0)
                goto st_accel_set_fullscale_error;

        sdata->current_fullscale = &sdata->sensor_settings->fs.fs_avl[i];
        return err;

st_accel_set_fullscale_error:
        dev_err(indio_dev->dev.parent, "failed to set new fullscale.\n");
        return err;
}

int st_sensors_set_enable(struct iio_dev *indio_dev, bool enable)
{
        u8 tmp_value;
        int err = -EINVAL;
        bool found = false;
        struct st_sensor_odr_avl odr_out = {0, 0};
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        if (enable) {
                tmp_value = sdata->sensor_settings->pw.value_on;
                if ((sdata->sensor_settings->odr.addr ==
                                        sdata->sensor_settings->pw.addr) &&
                                (sdata->sensor_settings->odr.mask ==
                                        sdata->sensor_settings->pw.mask)) {
                        err = st_sensors_match_odr(sdata->sensor_settings,
                                                        sdata->odr, &odr_out);
                        if (err < 0)
                                goto set_enable_error;
                        tmp_value = odr_out.value;
                        found = true;
                }
                err = st_sensors_write_data_with_mask(indio_dev,
                                sdata->sensor_settings->pw.addr,
                                sdata->sensor_settings->pw.mask, tmp_value);
                if (err < 0)
                        goto set_enable_error;

                sdata->enabled = true;

                if (found)
                        sdata->odr = odr_out.hz;
        } else {
                err = st_sensors_write_data_with_mask(indio_dev,
                                sdata->sensor_settings->pw.addr,
                                sdata->sensor_settings->pw.mask,
                                sdata->sensor_settings->pw.value_off);
                if (err < 0)
                        goto set_enable_error;

                sdata->enabled = false;
        }

set_enable_error:
        return err;
}
EXPORT_SYMBOL_NS(st_sensors_set_enable, "IIO_ST_SENSORS");

int st_sensors_set_axis_enable(struct iio_dev *indio_dev, u8 axis_enable)
{
        struct st_sensor_data *sdata = iio_priv(indio_dev);
        int err = 0;

        if (sdata->sensor_settings->enable_axis.addr)
                err = st_sensors_write_data_with_mask(indio_dev,
                                sdata->sensor_settings->enable_axis.addr,
                                sdata->sensor_settings->enable_axis.mask,
                                axis_enable);
        return err;
}
EXPORT_SYMBOL_NS(st_sensors_set_axis_enable, "IIO_ST_SENSORS");


int st_sensors_power_enable(struct iio_dev *indio_dev)
{
        static const char * const regulator_names[] = { "vdd", "vddio" };
        struct device *parent = indio_dev->dev.parent;
        int err;

        /* Regulators not mandatory, but if requested we should enable them. */
        err = devm_regulator_bulk_get_enable(parent,
                                             ARRAY_SIZE(regulator_names),
                                             regulator_names);
        if (err)
                return dev_err_probe(parent, err, "unable to enable supplies\n");

        return 0;
}
EXPORT_SYMBOL_NS(st_sensors_power_enable, "IIO_ST_SENSORS");

static int st_sensors_set_drdy_int_pin(struct iio_dev *indio_dev,
                                        struct st_sensors_platform_data *pdata)
{
        struct device *parent = indio_dev->dev.parent;
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        /* Sensor does not support interrupts */
        if (!sdata->sensor_settings->drdy_irq.int1.addr &&
            !sdata->sensor_settings->drdy_irq.int2.addr) {
                if (pdata->drdy_int_pin)
                        dev_info(parent,
                                 "DRDY on pin INT%d specified, but sensor does not support interrupts\n",
                                 pdata->drdy_int_pin);
                return 0;
        }

        switch (pdata->drdy_int_pin) {
        case 1:
                if (!sdata->sensor_settings->drdy_irq.int1.mask) {
                        dev_err(parent, "DRDY on INT1 not available.\n");
                        return -EINVAL;
                }
                sdata->drdy_int_pin = 1;
                break;
        case 2:
                if (!sdata->sensor_settings->drdy_irq.int2.mask) {
                        dev_err(parent, "DRDY on INT2 not available.\n");
                        return -EINVAL;
                }
                sdata->drdy_int_pin = 2;
                break;
        default:
                dev_err(parent, "DRDY on pdata not valid.\n");
                return -EINVAL;
        }

        if (pdata->open_drain) {
                if (!sdata->sensor_settings->drdy_irq.int1.addr_od &&
                    !sdata->sensor_settings->drdy_irq.int2.addr_od)
                        dev_err(parent,
                                "open drain requested but unsupported.\n");
                else
                        sdata->int_pin_open_drain = true;
        }

        return 0;
}

static struct st_sensors_platform_data *st_sensors_dev_probe(struct device *dev,
                struct st_sensors_platform_data *defdata)
{
        struct st_sensors_platform_data *pdata;
        u32 val;

        if (!dev_fwnode(dev))
                return NULL;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return ERR_PTR(-ENOMEM);
        if (!device_property_read_u32(dev, "st,drdy-int-pin", &val) && (val <= 2))
                pdata->drdy_int_pin = (u8) val;
        else
                pdata->drdy_int_pin = defdata ? defdata->drdy_int_pin : 0;

        pdata->open_drain = device_property_read_bool(dev, "drive-open-drain");

        return pdata;
}

/**
 * st_sensors_dev_name_probe() - device probe for ST sensor name
 * @dev: driver model representation of the device.
 * @name: device name buffer reference.
 * @len: device name buffer length.
 *
 * In effect this function matches an ID to an internal kernel
 * name for a certain sensor device, so that the rest of the autodetection can
 * rely on that name from this point on. I2C/SPI devices will be renamed
 * to match the internal kernel convention.
 */
void st_sensors_dev_name_probe(struct device *dev, char *name, int len)
{
        const void *match;

        match = device_get_match_data(dev);
        if (!match)
                return;

        /* The name from the match takes precedence if present */
        strscpy(name, match, len);
}
EXPORT_SYMBOL_NS(st_sensors_dev_name_probe, "IIO_ST_SENSORS");

int st_sensors_init_sensor(struct iio_dev *indio_dev,
                                        struct st_sensors_platform_data *pdata)
{
        struct device *parent = indio_dev->dev.parent;
        struct st_sensor_data *sdata = iio_priv(indio_dev);
        struct st_sensors_platform_data *of_pdata;
        int err = 0;

        mutex_init(&sdata->odr_lock);

        /* If OF/DT pdata exists, it will take precedence of anything else */
        of_pdata = st_sensors_dev_probe(parent, pdata);
        if (IS_ERR(of_pdata))
                return PTR_ERR(of_pdata);
        if (of_pdata)
                pdata = of_pdata;

        if (pdata) {
                err = st_sensors_set_drdy_int_pin(indio_dev, pdata);
                if (err < 0)
                        return err;
        }

        err = st_sensors_set_enable(indio_dev, false);
        if (err < 0)
                return err;

        /* Disable DRDY, this might be still be enabled after reboot. */
        err = st_sensors_set_dataready_irq(indio_dev, false);
        if (err < 0)
                return err;

        if (sdata->current_fullscale) {
                err = st_sensors_set_fullscale(indio_dev,
                                                sdata->current_fullscale->num);
                if (err < 0)
                        return err;
        } else
                dev_info(parent, "Full-scale not possible\n");

        err = st_sensors_set_odr(indio_dev, sdata->odr);
        if (err < 0)
                return err;

        /* set BDU */
        if (sdata->sensor_settings->bdu.addr) {
                err = st_sensors_write_data_with_mask(indio_dev,
                                        sdata->sensor_settings->bdu.addr,
                                        sdata->sensor_settings->bdu.mask, true);
                if (err < 0)
                        return err;
        }

        /* set DAS */
        if (sdata->sensor_settings->das.addr) {
                err = st_sensors_write_data_with_mask(indio_dev,
                                        sdata->sensor_settings->das.addr,
                                        sdata->sensor_settings->das.mask, 1);
                if (err < 0)
                        return err;
        }

        if (sdata->int_pin_open_drain) {
                u8 addr, mask;

                if (sdata->drdy_int_pin == 1) {
                        addr = sdata->sensor_settings->drdy_irq.int1.addr_od;
                        mask = sdata->sensor_settings->drdy_irq.int1.mask_od;
                } else {
                        addr = sdata->sensor_settings->drdy_irq.int2.addr_od;
                        mask = sdata->sensor_settings->drdy_irq.int2.mask_od;
                }

                dev_info(parent,
                         "set interrupt line to open drain mode on pin %d\n",
                         sdata->drdy_int_pin);
                err = st_sensors_write_data_with_mask(indio_dev, addr,
                                                      mask, 1);
                if (err < 0)
                        return err;
        }

        err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);

        return err;
}
EXPORT_SYMBOL_NS(st_sensors_init_sensor, "IIO_ST_SENSORS");

int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable)
{
        int err;
        u8 drdy_addr, drdy_mask;
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        if (!sdata->sensor_settings->drdy_irq.int1.addr &&
            !sdata->sensor_settings->drdy_irq.int2.addr) {
                /*
                 * there are some devices (e.g. LIS3MDL) where drdy line is
                 * routed to a given pin and it is not possible to select a
                 * different one. Take into account irq status register
                 * to understand if irq trigger can be properly supported
                 */
                if (sdata->sensor_settings->drdy_irq.stat_drdy.addr)
                        sdata->hw_irq_trigger = enable;
                return 0;
        }

        /* Enable/Disable the interrupt generator 1. */
        if (sdata->sensor_settings->drdy_irq.ig1.en_addr > 0) {
                err = st_sensors_write_data_with_mask(indio_dev,
                                sdata->sensor_settings->drdy_irq.ig1.en_addr,
                                sdata->sensor_settings->drdy_irq.ig1.en_mask,
                                (int)enable);
                if (err < 0)
                        goto st_accel_set_dataready_irq_error;
        }

        if (sdata->drdy_int_pin == 1) {
                drdy_addr = sdata->sensor_settings->drdy_irq.int1.addr;
                drdy_mask = sdata->sensor_settings->drdy_irq.int1.mask;
        } else {
                drdy_addr = sdata->sensor_settings->drdy_irq.int2.addr;
                drdy_mask = sdata->sensor_settings->drdy_irq.int2.mask;
        }

        /* Flag to the poll function that the hardware trigger is in use */
        sdata->hw_irq_trigger = enable;

        /* Enable/Disable the interrupt generator for data ready. */
        err = st_sensors_write_data_with_mask(indio_dev, drdy_addr,
                                              drdy_mask, (int)enable);

st_accel_set_dataready_irq_error:
        return err;
}
EXPORT_SYMBOL_NS(st_sensors_set_dataready_irq, "IIO_ST_SENSORS");

int st_sensors_set_fullscale_by_gain(struct iio_dev *indio_dev, int scale)
{
        int err = -EINVAL, i;
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
                if ((sdata->sensor_settings->fs.fs_avl[i].gain == scale) &&
                                (sdata->sensor_settings->fs.fs_avl[i].gain != 0)) {
                        err = 0;
                        break;
                }
        }
        if (err < 0)
                goto st_sensors_match_scale_error;

        err = st_sensors_set_fullscale(indio_dev,
                                sdata->sensor_settings->fs.fs_avl[i].num);

st_sensors_match_scale_error:
        return err;
}
EXPORT_SYMBOL_NS(st_sensors_set_fullscale_by_gain, "IIO_ST_SENSORS");

static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
                                     struct iio_chan_spec const *ch, int *data)
{
        int err;
        u8 *outdata;
        struct st_sensor_data *sdata = iio_priv(indio_dev);
        unsigned int byte_for_channel;

        byte_for_channel = DIV_ROUND_UP(ch->scan_type.realbits +
                                        ch->scan_type.shift, 8);
        outdata = kmalloc(byte_for_channel, GFP_DMA | GFP_KERNEL);
        if (!outdata)
                return -ENOMEM;

        err = regmap_bulk_read(sdata->regmap, ch->address,
                               outdata, byte_for_channel);
        if (err < 0)
                goto st_sensors_free_memory;

        if (byte_for_channel == 1)
                *data = (s8)*outdata;
        else if (byte_for_channel == 2)
                *data = (s16)get_unaligned_le16(outdata);
        else if (byte_for_channel == 3)
                *data = (s32)sign_extend32(get_unaligned_le24(outdata), 23);

st_sensors_free_memory:
        kfree(outdata);

        return err;
}

int st_sensors_read_info_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *ch, int *val)
{
        int err;
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        if (!iio_device_claim_direct(indio_dev))
                return -EBUSY;

        mutex_lock(&sdata->odr_lock);

        err = st_sensors_set_enable(indio_dev, true);
        if (err < 0)
                goto out;

        msleep((sdata->sensor_settings->bootime * 1000) / sdata->odr);
        err = st_sensors_read_axis_data(indio_dev, ch, val);
        if (err < 0)
                goto out;

        *val = *val >> ch->scan_type.shift;

        err = st_sensors_set_enable(indio_dev, false);

out:
        mutex_unlock(&sdata->odr_lock);
        iio_device_release_direct(indio_dev);

        return err;
}
EXPORT_SYMBOL_NS(st_sensors_read_info_raw, "IIO_ST_SENSORS");

/*
 * st_sensors_get_settings_index() - get index of the sensor settings for a
 *                                   specific device from list of settings
 * @name: device name buffer reference.
 * @list: sensor settings list.
 * @list_length: length of sensor settings list.
 *
 * Return: non negative number on success (valid index),
 *         negative error code otherwise.
 */
int st_sensors_get_settings_index(const char *name,
                                  const struct st_sensor_settings *list,
                                  const int list_length)
{
        int i, n;

        for (i = 0; i < list_length; i++) {
                for (n = 0; n < ST_SENSORS_MAX_4WAI; n++) {
                        if (strcmp(name, list[i].sensors_supported[n]) == 0)
                                return i;
                }
        }

        return -ENODEV;
}
EXPORT_SYMBOL_NS(st_sensors_get_settings_index, "IIO_ST_SENSORS");

/*
 * st_sensors_verify_id() - verify sensor ID (WhoAmI) is matching with the
 *                          expected value
 * @indio_dev: IIO device reference.
 *
 * Return: 0 on success (valid sensor ID), else a negative error code.
 */
int st_sensors_verify_id(struct iio_dev *indio_dev)
{
        struct st_sensor_data *sdata = iio_priv(indio_dev);
        struct device *parent = indio_dev->dev.parent;
        int wai, err;

        if (sdata->sensor_settings->wai_addr) {
                err = regmap_read(sdata->regmap,
                                  sdata->sensor_settings->wai_addr, &wai);
                if (err < 0) {
                        return dev_err_probe(parent, err,
                                             "failed to read Who-Am-I register.\n");
                }

                if (sdata->sensor_settings->wai != wai) {
                        dev_warn(parent, "%s: WhoAmI mismatch (0x%x).\n",
                                 indio_dev->name, wai);
                }
        }

        return 0;
}
EXPORT_SYMBOL_NS(st_sensors_verify_id, "IIO_ST_SENSORS");

ssize_t st_sensors_sysfs_sampling_frequency_avail(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        int i, len = 0;
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        for (i = 0; i < ST_SENSORS_ODR_LIST_MAX; i++) {
                if (sdata->sensor_settings->odr.odr_avl[i].hz == 0)
                        break;

                len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
                                sdata->sensor_settings->odr.odr_avl[i].hz);
        }
        buf[len - 1] = '\n';

        return len;
}
EXPORT_SYMBOL_NS(st_sensors_sysfs_sampling_frequency_avail, "IIO_ST_SENSORS");

ssize_t st_sensors_sysfs_scale_avail(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        int i, len = 0, q, r;
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct st_sensor_data *sdata = iio_priv(indio_dev);

        for (i = 0; i < ST_SENSORS_FULLSCALE_AVL_MAX; i++) {
                if (sdata->sensor_settings->fs.fs_avl[i].num == 0)
                        break;

                q = sdata->sensor_settings->fs.fs_avl[i].gain / 1000000;
                r = sdata->sensor_settings->fs.fs_avl[i].gain % 1000000;

                len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ", q, r);
        }
        buf[len - 1] = '\n';

        return len;
}
EXPORT_SYMBOL_NS(st_sensors_sysfs_scale_avail, "IIO_ST_SENSORS");

MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics ST-sensors core");
MODULE_LICENSE("GPL v2");