On Fri, 31 Jul 2015, Teodora Baluta wrote:
> This patch adds support for buffered readings for the 3-axis
> accelerometer mxc4005.
some comments below
> Signed-off-by: Teodora Baluta <teodora.baluta@xxxxxxxxx>
> ---
> drivers/iio/accel/Kconfig | 2 ++
> drivers/iio/accel/mxc4005.c | 75 ++++++++++++++++++++++++++++++++++++++++++---
> 2 files changed, 73 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 7f534a3..e8d135e 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -140,6 +140,8 @@ config MMA9553
> config MXC4005
> tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
> depends on I2C
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> select REGMAP_I2C
> help
> Say yes here to build support for the Memsic MXC4005XC 3-axis
> diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
> index 0f0410c..114c14d 100644
> --- a/drivers/iio/accel/mxc4005.c
> +++ b/drivers/iio/accel/mxc4005.c
> @@ -19,6 +19,9 @@
> #include <linux/acpi.h>
> #include <linux/regmap.h>
> #include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
>
> #define MXC4005_DRV_NAME "mxc4005"
> #define MXC4005_REGMAP_NAME "mxc4005_regmap"
> @@ -54,6 +57,7 @@ struct mxc4005_data {
> struct i2c_client *client;
> struct mutex mutex;
> struct regmap *regmap;
> + s16 buffer[8];
be16 buffer[3]; ?!
> };
>
> /*
> @@ -125,6 +129,20 @@ static const struct regmap_config mxc4005_regmap_config = {
> .writeable_reg = mxc4005_is_writeable_reg,
> };
>
> +static int mxc4005_read_xyz(struct mxc4005_data *data)
> +{
> + int ret;
> +
> + ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
> + (u8 *) data->buffer, sizeof(data->buffer));
sizeof(data->buffer) == sizeof(s16) * 8 == 16 bytes, but actually the
sensor data is just 6 bytes!?
> + if (ret < 0) {
> + dev_err(&data->client->dev, "failed to read axes\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int mxc4005_read_axis(struct mxc4005_data *data,
> int axis)
> {
> @@ -190,6 +208,7 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
> int *val, int *val2, long mask)
> {
> struct mxc4005_data *data = iio_priv(indio_dev);
> + int axis = chan->scan_index;
why?
BTW w.r.t the initial patch: chan->address could store the register
address directly, so MXC4005_AXIS_TO_REG() could be dropped
> int ret;
>
> switch (mask) {
> @@ -200,12 +219,13 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
> return -EBUSY;
>
> mutex_lock(&data->mutex);
> - ret = mxc4005_read_axis(data, chan->address);
> + ret = mxc4005_read_axis(data, axis);
> mutex_unlock(&data->mutex);
> if (ret < 0)
> return ret;
> ret = be16_to_cpu(ret);
> - *val = sign_extend32(ret >> 4, 11);
> + *val = sign_extend32(ret >> chan->scan_type.shift,
> + chan->scan_type.realbits - 1);
> return IIO_VAL_INT;
> default:
> return -EINVAL;
> @@ -259,17 +279,47 @@ static const struct iio_info mxc4005_info = {
> .type = IIO_ACCEL, \
> .modified = 1, \
> .channel2 = IIO_MOD_##_axis, \
> - .address = AXIS_##_axis, \
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> + .scan_index = AXIS_##_axis, \
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 12, \
> + .storagebits = 16, \
> + .shift = 4, \
> + .endianness = IIO_BE, \
> + }, \
> }
>
> static const struct iio_chan_spec mxc4005_channels[] = {
> MXC4005_CHANNEL(X),
> MXC4005_CHANNEL(Y),
> MXC4005_CHANNEL(Z),
> + IIO_CHAN_SOFT_TIMESTAMP(3),
> };
>
> +static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
> +{
> + struct iio_poll_func *pf = private;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct mxc4005_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&data->mutex);
> + ret = mxc4005_read_xyz(data);
this always reads all channels, what if only one channel is enabled by the
user? use available_scan_masks...
> + mutex_unlock(&data->mutex);
> + if (ret < 0)
> + goto err;
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> + iio_get_time_ns());
> +
> +err:
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> static int mxc4005_chip_init(struct mxc4005_data *data)
> {
> int ret;
> @@ -324,14 +374,29 @@ static int mxc4005_probe(struct i2c_client *client,
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &mxc4005_info;
>
> + ret = iio_triggered_buffer_setup(indio_dev,
> + &iio_pollfunc_store_time,
> + mxc4005_trigger_handler,
> + NULL);
> + if (ret < 0) {
> + dev_err(&client->dev,
> + "failed to setup iio triggered buffer\n");
> + return ret;
> + }
> +
> ret = iio_device_register(indio_dev);
> if (ret < 0) {
> dev_err(&client->dev,
> "unable to register iio device %d\n", ret);
> - return ret;
> + goto err_buffer_cleanup;
> }
>
> return 0;
> +
> +err_buffer_cleanup:
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return ret;
> }
>
> static int mxc4005_remove(struct i2c_client *client)
> @@ -340,6 +405,8 @@ static int mxc4005_remove(struct i2c_client *client)
>
> iio_device_unregister(indio_dev);
>
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> return 0;
> }
>
>
--
Peter Meerwald
+43-664-2444418 (mobile)
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