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    Subject[PATCH 1/8] iio: mma8452: refactor for seperating chip specific data
    Date
    This adds a struct mma_chip_info to hold data that will remain specific to
    the chip in use. It is provided during probe() and linked in
    struct of_device_id.

    Also this suggests that the driver is called "mma8452" and now handles the
    MMA8452Q device, but is not limited to it.

    Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
    Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
    ---
    drivers/iio/accel/mma8452.c | 161 ++++++++++++++++++++++++++++++--------------
    1 file changed, 110 insertions(+), 51 deletions(-)

    diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
    index e8e2077..b2ebfcb 100644
    --- a/drivers/iio/accel/mma8452.c
    +++ b/drivers/iio/accel/mma8452.c
    @@ -23,7 +23,9 @@
    #include <linux/iio/triggered_buffer.h>
    #include <linux/iio/events.h>
    #include <linux/delay.h>
    +#include <linux/of_device.h>

    +#define DRIVER_NAME "mma8452"
    #define MMA8452_STATUS 0x00
    #define MMA8452_OUT_X 0x01 /* MSB first, 12-bit */
    #define MMA8452_OUT_Y 0x03
    @@ -78,6 +80,25 @@ struct mma8452_data {
    struct mutex lock;
    u8 ctrl_reg1;
    u8 data_cfg;
    + const struct mma_chip_info *chip_info;
    +};
    +
    +struct mma_chip_info {
    + u8 chip_id;
    + const struct iio_chan_spec *channels;
    + int num_channels;
    + /* 3 modes: 2g, 4g, 8g; 2 ints: m/s^2 and micro m/s^2 */
    + const int mma_scales[3][2];
    + u8 ev_cfg;
    + u8 ev_cfg_ele;
    + u8 ev_cfg_chan_shift;
    + u8 ev_src;
    + u8 ev_src_xe;
    + u8 ev_src_ye;
    + u8 ev_src_ze;
    + u8 ev_ths;
    + u8 ev_ths_mask;
    + u8 ev_count;
    };

    static int mma8452_drdy(struct mma8452_data *data)
    @@ -143,16 +164,6 @@ static const int mma8452_samp_freq[8][2] = {
    {6, 250000}, {1, 560000}
    };

    -/*
    - * Hardware has fullscale of -2G, -4G, -8G corresponding to raw value -2048
    - * The userspace interface uses m/s^2 and we declare micro units
    - * So scale factor is given by:
    - * g * N * 1000000 / 2048 for N = 2, 4, 8 and g=9.80665
    - */
    -static const int mma8452_scales[3][2] = {
    - {0, 9577}, {0, 19154}, {0, 38307}
    -};
    -
    /* Datasheet table 35 (step time vs sample frequency) */
    static const int mma8452_transient_time_step_us[8] = {
    1250,
    @@ -187,8 +198,11 @@ static ssize_t mma8452_show_samp_freq_avail(struct device *dev,
    static ssize_t mma8452_show_scale_avail(struct device *dev,
    struct device_attribute *attr, char *buf)
    {
    - return mma8452_show_int_plus_micros(buf, mma8452_scales,
    - ARRAY_SIZE(mma8452_scales));
    + struct mma8452_data *data = iio_priv(i2c_get_clientdata(
    + to_i2c_client(dev)));
    +
    + return mma8452_show_int_plus_micros(buf, data->chip_info->mma_scales,
    + ARRAY_SIZE(data->chip_info->mma_scales));
    }

    static ssize_t mma8452_show_hp_cutoff_avail(struct device *dev,
    @@ -219,8 +233,8 @@ static int mma8452_get_samp_freq_index(struct mma8452_data *data,
    static int mma8452_get_scale_index(struct mma8452_data *data,
    int val, int val2)
    {
    - return mma8452_get_int_plus_micros_index(mma8452_scales,
    - ARRAY_SIZE(mma8452_scales), val, val2);
    + return mma8452_get_int_plus_micros_index(data->chip_info->mma_scales,
    + ARRAY_SIZE(data->chip_info->mma_scales), val, val2);
    }

    static int mma8452_get_hp_filter_index(struct mma8452_data *data,
    @@ -229,7 +243,7 @@ static int mma8452_get_hp_filter_index(struct mma8452_data *data,
    int i = mma8452_get_odr_index(data);

    return mma8452_get_int_plus_micros_index(mma8452_hp_filter_cutoff[i],
    - ARRAY_SIZE(mma8452_scales[0]), val, val2);
    + ARRAY_SIZE(data->chip_info->mma_scales[0]), val, val2);
    }

    static int mma8452_read_hp_filter(struct mma8452_data *data, int *hz, int *uHz)
    @@ -266,13 +280,14 @@ static int mma8452_read_raw(struct iio_dev *indio_dev,
    mutex_unlock(&data->lock);
    if (ret < 0)
    return ret;
    - *val = sign_extend32(
    - be16_to_cpu(buffer[chan->scan_index]) >> 4, 11);
    + *val = sign_extend32(be16_to_cpu(
    + buffer[chan->scan_index]) >> chan->scan_type.shift,
    + chan->scan_type.realbits - 1);
    return IIO_VAL_INT;
    case IIO_CHAN_INFO_SCALE:
    i = data->data_cfg & MMA8452_DATA_CFG_FS_MASK;
    - *val = mma8452_scales[i][0];
    - *val2 = mma8452_scales[i][1];
    + *val = data->chip_info->mma_scales[i][0];
    + *val2 = data->chip_info->mma_scales[i][1];
    return IIO_VAL_INT_PLUS_MICRO;
    case IIO_CHAN_INFO_SAMP_FREQ:
    i = mma8452_get_odr_index(data);
    @@ -420,16 +435,16 @@ static int mma8452_read_thresh(struct iio_dev *indio_dev,
    switch (info) {
    case IIO_EV_INFO_VALUE:
    ret = i2c_smbus_read_byte_data(data->client,
    - MMA8452_TRANSIENT_THS);
    + data->chip_info->ev_ths);
    if (ret < 0)
    return ret;

    - *val = ret & MMA8452_TRANSIENT_THS_MASK;
    + *val = ret & data->chip_info->ev_ths_mask;
    return IIO_VAL_INT;

    case IIO_EV_INFO_PERIOD:
    ret = i2c_smbus_read_byte_data(data->client,
    - MMA8452_TRANSIENT_COUNT);
    + data->chip_info->ev_count);
    if (ret < 0)
    return ret;

    @@ -472,8 +487,11 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev,

    switch (info) {
    case IIO_EV_INFO_VALUE:
    - return mma8452_change_config(data, MMA8452_TRANSIENT_THS,
    - val & MMA8452_TRANSIENT_THS_MASK);
    + if (val < 0 || val > 127) /* LSB 0.6178 m/s^2 */
    + return -EINVAL;
    +
    + return mma8452_change_config(data, data->chip_info->ev_ths,
    + val);

    case IIO_EV_INFO_PERIOD:
    steps = (val * USEC_PER_SEC + val2) /
    @@ -483,7 +501,7 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev,
    if (steps > 0xff)
    return -EINVAL;

    - return mma8452_change_config(data, MMA8452_TRANSIENT_COUNT,
    + return mma8452_change_config(data, data->chip_info->ev_count,
    steps);
    case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
    reg = i2c_smbus_read_byte_data(data->client,
    @@ -512,13 +530,15 @@ static int mma8452_read_event_config(struct iio_dev *indio_dev,
    enum iio_event_direction dir)
    {
    struct mma8452_data *data = iio_priv(indio_dev);
    + const struct mma_chip_info *chip = data->chip_info;
    int ret;

    - ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG);
    + ret = i2c_smbus_read_byte_data(data->client,
    + data->chip_info->ev_cfg);
    if (ret < 0)
    return ret;

    - return ret & MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index) ? 1 : 0;
    + return ret & BIT(chan->scan_index + chip->ev_cfg_chan_shift) ? 1 : 0;
    }

    static int mma8452_write_event_config(struct iio_dev *indio_dev,
    @@ -528,20 +548,21 @@ static int mma8452_write_event_config(struct iio_dev *indio_dev,
    int state)
    {
    struct mma8452_data *data = iio_priv(indio_dev);
    + const struct mma_chip_info *chip = data->chip_info;
    int val;

    - val = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG);
    + val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
    if (val < 0)
    return val;

    if (state)
    - val |= MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index);
    + val |= BIT(chan->scan_index + chip->ev_cfg_chan_shift);
    else
    - val &= ~MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index);
    + val &= ~BIT(chan->scan_index + chip->ev_cfg_chan_shift);

    val |= MMA8452_TRANSIENT_CFG_ELE;

    - return mma8452_change_config(data, MMA8452_TRANSIENT_CFG, val);
    + return mma8452_change_config(data, chip->ev_cfg, val);
    }

    static void mma8452_transient_interrupt(struct iio_dev *indio_dev)
    @@ -550,25 +571,25 @@ static void mma8452_transient_interrupt(struct iio_dev *indio_dev)
    s64 ts = iio_get_time_ns();
    int src;

    - src = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_SRC);
    + src = i2c_smbus_read_byte_data(data->client, data->chip_info->ev_src);
    if (src < 0)
    return;

    - if (src & MMA8452_TRANSIENT_SRC_XTRANSE)
    + if (src & data->chip_info->ev_src_xe)
    iio_push_event(indio_dev,
    IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X,
    IIO_EV_TYPE_THRESH,
    IIO_EV_DIR_RISING),
    ts);

    - if (src & MMA8452_TRANSIENT_SRC_YTRANSE)
    + if (src & data->chip_info->ev_src_ye)
    iio_push_event(indio_dev,
    IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Y,
    IIO_EV_TYPE_THRESH,
    IIO_EV_DIR_RISING),
    ts);

    - if (src & MMA8452_TRANSIENT_SRC_ZTRANSE)
    + if (src & data->chip_info->ev_src_ze)
    iio_push_event(indio_dev,
    IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Z,
    IIO_EV_TYPE_THRESH,
    @@ -669,7 +690,7 @@ static struct attribute_group mma8452_event_attribute_group = {
    .name = "events",
    };

    -#define MMA8452_CHANNEL(axis, idx) { \
    +#define MMA8452_CHANNEL(axis, idx, bits) { \
    .type = IIO_ACCEL, \
    .modified = 1, \
    .channel2 = IIO_MOD_##axis, \
    @@ -681,9 +702,9 @@ static struct attribute_group mma8452_event_attribute_group = {
    .scan_index = idx, \
    .scan_type = { \
    .sign = 's', \
    - .realbits = 12, \
    + .realbits = (bits), \
    .storagebits = 16, \
    - .shift = 4, \
    + .shift = 16 - (bits), \
    .endianness = IIO_BE, \
    }, \
    .event_spec = mma8452_transient_event, \
    @@ -691,12 +712,42 @@ static struct attribute_group mma8452_event_attribute_group = {
    }

    static const struct iio_chan_spec mma8452_channels[] = {
    - MMA8452_CHANNEL(X, 0),
    - MMA8452_CHANNEL(Y, 1),
    - MMA8452_CHANNEL(Z, 2),
    + MMA8452_CHANNEL(X, 0, 12),
    + MMA8452_CHANNEL(Y, 1, 12),
    + MMA8452_CHANNEL(Z, 2, 12),
    IIO_CHAN_SOFT_TIMESTAMP(3),
    };

    +enum {
    + mma8452,
    +};
    +
    +/*
    + * Hardware has fullscale of -2G, -4G, -8G corresponding to raw value -2048
    + * for 12 bit or -512 for 10 bit.
    + * The userspace interface uses m/s^2 and we declare micro units
    + * So scale factor is given by:
    + * g * N * 1000000 / 2048 for N = 2, 4, 8 and g=9.80665
    + */
    +
    +static const struct mma_chip_info mma_chip_info_table[] = {
    + [mma8452] = {
    + .chip_id = MMA8452_DEVICE_ID,
    + .channels = mma8452_channels,
    + .num_channels = ARRAY_SIZE(mma8452_channels),
    + .mma_scales = { {0, 9577}, {0, 19154}, {0, 38307} },
    + .ev_cfg = MMA8452_TRANSIENT_CFG,
    + .ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
    + .ev_cfg_chan_shift = 1,
    + .ev_src = MMA8452_TRANSIENT_SRC,
    + .ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
    + .ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
    + .ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
    + .ev_ths = MMA8452_TRANSIENT_THS,
    + .ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
    + .ev_count = MMA8452_TRANSIENT_COUNT,
    + },
    +};
    static struct attribute *mma8452_attributes[] = {
    &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
    &iio_dev_attr_in_accel_scale_available.dev_attr.attr,
    @@ -813,12 +864,18 @@ static int mma8452_reset(struct i2c_client *client)
    return -ETIMEDOUT;
    }

    +static const struct of_device_id mma8452_dt_ids[] = {
    + { .compatible = "fsl,mma8452", .data = &mma_chip_info_table[mma8452] },
    + { }
    +};
    +
    static int mma8452_probe(struct i2c_client *client,
    const struct i2c_device_id *id)
    {
    struct mma8452_data *data;
    struct iio_dev *indio_dev;
    int ret;
    + const struct of_device_id *match;

    ret = i2c_smbus_read_byte_data(client, MMA8452_WHO_AM_I);
    if (ret < 0)
    @@ -826,21 +883,28 @@ static int mma8452_probe(struct i2c_client *client,
    if (ret != MMA8452_DEVICE_ID)
    return -ENODEV;

    + match = of_match_device(mma8452_dt_ids, &client->dev);
    + if (!match) {
    + dev_err(&client->dev, "unknown device model\n");
    + return -ENODEV;
    + }
    +
    indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
    if (!indio_dev)
    return -ENOMEM;

    data = iio_priv(indio_dev);
    data->client = client;
    + data->chip_info = match->data;
    mutex_init(&data->lock);

    i2c_set_clientdata(client, indio_dev);
    indio_dev->info = &mma8452_info;
    - indio_dev->name = id->name;
    + indio_dev->name = DRIVER_NAME;
    indio_dev->dev.parent = &client->dev;
    indio_dev->modes = INDIO_DIRECT_MODE;
    - indio_dev->channels = mma8452_channels;
    - indio_dev->num_channels = ARRAY_SIZE(mma8452_channels);
    + indio_dev->channels = data->chip_info->channels;
    + indio_dev->num_channels = data->chip_info->num_channels;
    indio_dev->available_scan_masks = mma8452_scan_masks;

    ret = mma8452_reset(client);
    @@ -959,19 +1023,14 @@ static SIMPLE_DEV_PM_OPS(mma8452_pm_ops, mma8452_suspend, mma8452_resume);
    #endif

    static const struct i2c_device_id mma8452_id[] = {
    - { "mma8452", 0 },
    + { "mma8452", mma8452 },
    { }
    };
    MODULE_DEVICE_TABLE(i2c, mma8452_id);

    -static const struct of_device_id mma8452_dt_ids[] = {
    - { .compatible = "fsl,mma8452" },
    - { }
    -};
    -
    static struct i2c_driver mma8452_driver = {
    .driver = {
    - .name = "mma8452",
    + .name = DRIVER_NAME,
    .of_match_table = of_match_ptr(mma8452_dt_ids),
    .pm = MMA8452_PM_OPS,
    },
    --
    2.1.4


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