ASoC: SDCA: Add parsing for Control range structures

DisCo/SDCA contains small buffers of data that hold ranges of valid
values for the various SDCA Controls. Add support for parsing these
from ACPI.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Link: https://patch.msgid.link/20250205113801.3699902-7-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/include/sound/sdca_function.h b/include/sound/sdca_function.h
index 64043090fe76e24bdb47d80a0b47d3eaae75a629..769ae68410647830e82854de55cd205a129e4a9c 100644 (file)
--- a/include/sound/sdca_function.h
+++ b/include/sound/sdca_function.h
@@ -612,6 +612,18 @@ enum sdca_access_layer {
        SDCA_ACCESS_LAYER_EXTENSION                     = 1 << 5,
 };
 
+/**
+ * struct sdca_control_range - SDCA Control range table
+ * @cols: Number of columns in the range table.
+ * @rows: Number of rows in the range table.
+ * @data: Array of values contained in the range table.
+ */
+struct sdca_control_range {
+       unsigned int cols;
+       unsigned int rows;
+       u32 *data;
+};
+
 /**
  * struct sdca_control - information for one SDCA Control
  * @label: Name for the Control, from SDCA Specification v1.0, section 7.1.7.
@@ -622,6 +634,7 @@ enum sdca_access_layer {
  * Control.
  * @cn_list: A bitmask showing the valid Control Numbers within this Control,
  * Control Numbers typically represent channels.
+ * @range: Buffer describing valid range of values for the Control.
  * @mode: Access mode of the Control.
  * @layers: Bitmask of access layers of the Control.
  * @deferrable: Indicates if the access to the Control can be deferred.
@@ -637,6 +650,7 @@ struct sdca_control {
        int interrupt_position;
        u64 cn_list;
 
+       struct sdca_control_range range;
        enum sdca_access_mode mode;
        u8 layers;
 

diff --git a/sound/soc/sdca/sdca_functions.c b/sound/soc/sdca/sdca_functions.c
index e495ccc5b4b6fe2bfa519971bc25438004090df9..d65b413f6d2f46e5d8e5fcbc0309ea3991b8f457 100644 (file)
--- a/sound/soc/sdca/sdca_functions.c
+++ b/sound/soc/sdca/sdca_functions.c
@@ -603,6 +603,44 @@ static unsigned int find_sdca_control_bits(const struct sdca_entity *entity,
        }
 }
 
+static int find_sdca_control_range(struct device *dev,
+                                  struct fwnode_handle *control_node,
+                                  struct sdca_control_range *range)
+{
+       u8 *range_list;
+       int num_range;
+       u16 *limits;
+       int i;
+
+       num_range = fwnode_property_count_u8(control_node, "mipi-sdca-control-range");
+       if (!num_range || num_range == -EINVAL)
+               return 0;
+       else if (num_range < 0)
+               return num_range;
+
+       range_list = devm_kcalloc(dev, num_range, sizeof(*range_list), GFP_KERNEL);
+       if (!range_list)
+               return -ENOMEM;
+
+       fwnode_property_read_u8_array(control_node, "mipi-sdca-control-range",
+                                     range_list, num_range);
+
+       limits = (u16 *)range_list;
+
+       range->cols = le16_to_cpu(limits[0]);
+       range->rows = le16_to_cpu(limits[1]);
+       range->data = (u32 *)&limits[2];
+
+       num_range = (num_range - (2 * sizeof(*limits))) / sizeof(*range->data);
+       if (num_range != range->cols * range->rows)
+               return -EINVAL;
+
+       for (i = 0; i < num_range; i++)
+               range->data[i] = le32_to_cpu(range->data[i]);
+
+       return 0;
+}
+
 /*
  * TODO: Add support for -cn- properties, allowing different channels to have
  * different defaults etc.
@@ -678,6 +716,13 @@ static int find_sdca_entity_control(struct device *dev, struct sdca_entity *enti
                break;
        }
 
+       ret = find_sdca_control_range(dev, control_node, &control->range);
+       if (ret) {
+               dev_err(dev, "%s: control %#x: range missing: %d\n",
+                       entity->label, control->sel, ret);
+               return ret;
+       }
+
        ret = fwnode_property_read_u64(control_node, "mipi-sdca-control-cn-list",
                                       &control->cn_list);
        if (ret == -EINVAL) {