iio: accel: st_sensors: Support generic mounting matrix

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.

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Cc: Daniel Drake <drake@endlessm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210518230722.522446-2-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
index dc32ebe..9abcebf 100644 (file)
--- a/drivers/iio/accel/st_accel_core.c
+++ b/drivers/iio/accel/st_accel_core.c
@@ -41,51 +41,74 @@
 #define ST_ACCEL_FS_AVL_200G                   200
 #define ST_ACCEL_FS_AVL_400G                   400
 
+static const struct iio_mount_matrix *
+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 st_accel_mount_matrix_ext_info[] = {
+       IIO_MOUNT_MATRIX(IIO_SHARED_BY_ALL, st_accel_get_mount_matrix),
+       { }
+};
+
 static const struct iio_chan_spec st_accel_8bit_channels[] = {
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_X, 1, IIO_MOD_X, 's', IIO_LE, 8, 8,
-                       ST_ACCEL_DEFAULT_OUT_X_L_ADDR+1),
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+                       ST_ACCEL_DEFAULT_OUT_X_L_ADDR+1,
+                       st_accel_mount_matrix_ext_info),
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_Y, 1, IIO_MOD_Y, 's', IIO_LE, 8, 8,
-                       ST_ACCEL_DEFAULT_OUT_Y_L_ADDR+1),
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+                       ST_ACCEL_DEFAULT_OUT_Y_L_ADDR+1,
+                       st_accel_mount_matrix_ext_info),
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_Z, 1, IIO_MOD_Z, 's', IIO_LE, 8, 8,
-                       ST_ACCEL_DEFAULT_OUT_Z_L_ADDR+1),
+                       ST_ACCEL_DEFAULT_OUT_Z_L_ADDR+1,
+                       st_accel_mount_matrix_ext_info),
        IIO_CHAN_SOFT_TIMESTAMP(3)
 };
 
 static const struct iio_chan_spec st_accel_12bit_channels[] = {
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_X, 1, IIO_MOD_X, 's', IIO_LE, 12, 16,
-                       ST_ACCEL_DEFAULT_OUT_X_L_ADDR),
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+                       ST_ACCEL_DEFAULT_OUT_X_L_ADDR,
+                       st_accel_mount_matrix_ext_info),
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_Y, 1, IIO_MOD_Y, 's', IIO_LE, 12, 16,
-                       ST_ACCEL_DEFAULT_OUT_Y_L_ADDR),
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+                       ST_ACCEL_DEFAULT_OUT_Y_L_ADDR,
+                       st_accel_mount_matrix_ext_info),
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_Z, 1, IIO_MOD_Z, 's', IIO_LE, 12, 16,
-                       ST_ACCEL_DEFAULT_OUT_Z_L_ADDR),
+                       ST_ACCEL_DEFAULT_OUT_Z_L_ADDR,
+                       st_accel_mount_matrix_ext_info),
        IIO_CHAN_SOFT_TIMESTAMP(3)
 };
 
 static const struct iio_chan_spec st_accel_16bit_channels[] = {
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_X, 1, IIO_MOD_X, 's', IIO_LE, 16, 16,
-                       ST_ACCEL_DEFAULT_OUT_X_L_ADDR),
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+                       ST_ACCEL_DEFAULT_OUT_X_L_ADDR,
+                       st_accel_mount_matrix_ext_info),
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_Y, 1, IIO_MOD_Y, 's', IIO_LE, 16, 16,
-                       ST_ACCEL_DEFAULT_OUT_Y_L_ADDR),
-       ST_SENSORS_LSM_CHANNELS(IIO_ACCEL,
+                       ST_ACCEL_DEFAULT_OUT_Y_L_ADDR,
+                       st_accel_mount_matrix_ext_info),
+       ST_SENSORS_LSM_CHANNELS_EXT(IIO_ACCEL,
                        BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
                        ST_SENSORS_SCAN_Z, 1, IIO_MOD_Z, 's', IIO_LE, 16, 16,
-                       ST_ACCEL_DEFAULT_OUT_Z_L_ADDR),
+                       ST_ACCEL_DEFAULT_OUT_Z_L_ADDR,
+                       st_accel_mount_matrix_ext_info),
        IIO_CHAN_SOFT_TIMESTAMP(3)
 };
 
@@ -1162,25 +1185,10 @@ static const struct iio_trigger_ops st_accel_trigger_ops = {
 #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)
-{
-       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),
-       { },
-};
-
 /* 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};
@@ -1269,14 +1277,6 @@ static int apply_acpi_orientation(struct iio_dev *indio_dev,
        }
 
        /* Convert our integer matrix to a string-based iio_mount_matrix */
-       adata->mount_matrix = devm_kmalloc(&indio_dev->dev,
-                                          sizeof(*adata->mount_matrix),
-                                          GFP_KERNEL);
-       if (!adata->mount_matrix) {
-               ret = -ENOMEM;
-               goto out;
-       }
-
        for (i = 0; i < 3; i++) {
                for (j = 0; j < 3; j++) {
                        int matrix_val = final_ont[i][j];
@@ -1295,26 +1295,25 @@ static int apply_acpi_orientation(struct iio_dev *indio_dev,
                        default:
                                goto out;
                        }
-                       adata->mount_matrix->rotation[i * 3 + j] = str_value;
+                       adata->mount_matrix.rotation[i * 3 + j] = str_value;
                }
        }
 
-       /* 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);
+       if (ret)
+               dev_dbg(&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
 
@@ -1361,9 +1360,16 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
        if (!channels)
                return -ENOMEM;
 
-       if (apply_acpi_orientation(indio_dev, channels))
-               dev_warn(&indio_dev->dev,
-                        "failed to apply ACPI orientation data: %d\n", err);
+       /*
+        * First try specific ACPI methods to retrieve orientation then try the
+        * generic function.
+        */
+       err = apply_acpi_orientation(indio_dev);
+       if (err) {
+               err = iio_read_mount_matrix(adata->dev, &adata->mount_matrix);
+               if (err)
+                       return err;
+       }
 
        indio_dev->channels = channels;
        adata->current_fullscale = &adata->sensor_settings->fs.fs_avl[0];

diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h
index 8e0d76b..8bdbaf3 100644 (file)
--- a/include/linux/iio/common/st_sensors.h
+++ b/include/linux/iio/common/st_sensors.h
@@ -13,6 +13,7 @@
 #include <linux/i2c.h>
 #include <linux/spi/spi.h>
 #include <linux/irqreturn.h>
+#include <linux/iio/iio.h>
 #include <linux/iio/trigger.h>
 #include <linux/bitops.h>
 #include <linux/regulator/consumer.h>
@@ -221,6 +222,7 @@ struct st_sensor_settings {
  * struct st_sensor_data - ST sensor device status
  * @dev: Pointer to instance of struct device (I2C or SPI).
  * @trig: The trigger in use by the core driver.
+ * @mount_matrix: The mounting matrix of the sensor.
  * @sensor_settings: Pointer to the specific sensor settings in use.
  * @current_fullscale: Maximum range of measure by the sensor.
  * @vdd: Pointer to sensor's Vdd power supply
@@ -240,7 +242,7 @@ struct st_sensor_settings {
 struct st_sensor_data {
        struct device *dev;
        struct iio_trigger *trig;
-       struct iio_mount_matrix *mount_matrix;
+       struct iio_mount_matrix mount_matrix;
        struct st_sensor_settings *sensor_settings;
        struct st_sensor_fullscale_avl *current_fullscale;
        struct regulator *vdd;