On Sat, May 15, 2021 at 6:17 AM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
>
> The ST accelerators support a special type of quirky
> mounting matrix found in ACPI systems, but not a generic
> mounting matrix such as from the device tree.
>
> Augment the ACPI hack to be a bit more generic and
> accept a mounting matrix from device properties.
>
> This makes it possible to fix orientation on the Ux500
> HREF device.
I think this entire thread may be interesting to Hans, hence Cc him.
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Cc: Denis Ciocca <denis.ciocca@xxxxxx>
> Cc: Daniel Drake <drake@xxxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> drivers/iio/accel/st_accel_core.c | 51 ++++++++++++++++++++-----------
> 1 file changed, 34 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
> index 43c50167d220..cfbcf740e3cb 100644
> --- a/drivers/iio/accel/st_accel_core.c
> +++ b/drivers/iio/accel/st_accel_core.c
> @@ -1069,26 +1069,25 @@ static const struct iio_trigger_ops st_accel_trigger_ops = {
> #define ST_ACCEL_TRIGGER_OPS NULL
> #endif
>
> -#ifdef CONFIG_ACPI
> static const struct iio_mount_matrix *
> -get_mount_matrix(const struct iio_dev *indio_dev,
> - const struct iio_chan_spec *chan)
> +st_accel_get_mount_matrix(const struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan)
> {
> struct st_sensor_data *adata = iio_priv(indio_dev);
>
> return adata->mount_matrix;
> }
>
> -static const struct iio_chan_spec_ext_info mount_matrix_ext_info[] = {
> - IIO_MOUNT_MATRIX(IIO_SHARED_BY_ALL, get_mount_matrix),
> +static const struct iio_chan_spec_ext_info st_accel_mount_matrix_ext_info[] = {
> + IIO_MOUNT_MATRIX(IIO_SHARED_BY_ALL, st_accel_get_mount_matrix),
> { },
> };
>
> +#ifdef CONFIG_ACPI
> /* Read ST-specific _ONT orientation data from ACPI and generate an
> * appropriate mount matrix.
> */
> -static int apply_acpi_orientation(struct iio_dev *indio_dev,
> - struct iio_chan_spec *channels)
> +static int apply_acpi_orientation(struct iio_dev *indio_dev)
> {
> struct st_sensor_data *adata = iio_priv(indio_dev);
> struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
> @@ -1207,22 +1206,20 @@ static int apply_acpi_orientation(struct iio_dev *indio_dev,
> }
> }
>
> - /* Expose the mount matrix via ext_info */
> - for (i = 0; i < indio_dev->num_channels; i++)
> - channels[i].ext_info = mount_matrix_ext_info;
> -
> ret = 0;
> dev_info(&indio_dev->dev, "computed mount matrix from ACPI\n");
>
> out:
> kfree(buffer.pointer);
> + dev_warn(&indio_dev->dev,
> + "failed to apply ACPI orientation data: %d\n", ret);
> +
> return ret;
> }
> #else /* !CONFIG_ACPI */
> -static int apply_acpi_orientation(struct iio_dev *indio_dev,
> - struct iio_chan_spec *channels)
> +static int apply_acpi_orientation(struct iio_dev *indio_dev)
> {
> - return 0;
> + return -EINVAL;
> }
> #endif
>
> @@ -1251,6 +1248,7 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
> struct iio_chan_spec *channels;
> size_t channels_size;
> int err;
> + int i;
>
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->info = &accel_info;
> @@ -1275,9 +1273,28 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
> goto st_accel_power_off;
> }
>
> - if (apply_acpi_orientation(indio_dev, channels))
> - dev_warn(&indio_dev->dev,
> - "failed to apply ACPI orientation data: %d\n", err);
> + /* First try ACPI orientation then try the generic function */
> + err = apply_acpi_orientation(indio_dev);
> + if (err) {
> + adata->mount_matrix = devm_kmalloc(&indio_dev->dev,
> + sizeof(*adata->mount_matrix),
> + GFP_KERNEL);
> + if (!adata->mount_matrix) {
> + err = -ENOMEM;
> + goto st_accel_power_off;
> + }
> +
> + err = iio_read_mount_matrix(adata->dev, "mount-matrix",
> + adata->mount_matrix);
> + if (err)
> + goto st_accel_power_off;
> + }
> + /*
> + * We have at least an identity matrix, so expose the mount
> + * matrix via ext_info
> + */
> + for (i = 0; i < indio_dev->num_channels; i++)
> + channels[i].ext_info = st_accel_mount_matrix_ext_info;
>
> indio_dev->channels = channels;
> adata->current_fullscale = &adata->sensor_settings->fs.fs_avl[0];
> --
> 2.31.1
>
--
With Best Regards,
Andy Shevchenko
