ASoC: SDCA: Force some SDCA Controls to be volatile

Whilst SDCA does specify an Access Mode for each Control, there is not a
1-to-1 mapping between that and ASoC's internal representation. Some
registers require being treated as volatile from the hosts perspective
even in their Access Mode is Read-Write. Add an explicit list of SDCA
controls that should be forced volatile.

Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Link: https://patch.msgid.link/20251020155512.353774-10-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 60 insertions, 8 deletions

diff --git a/include/sound/sdca_function.h b/include/sound/sdca_function.h
index 51e12fcfc53c..ab9af84082c9 100644
--- a/include/sound/sdca_function.h
+++ b/include/sound/sdca_function.h
@@ -771,6 +771,7 @@ struct sdca_control {
 	u8 layers;
 
 	bool deferrable;
+	bool is_volatile;
 	bool has_default;
 	bool has_fixed;
 };
diff --git a/sound/soc/sdca/sdca_functions.c b/sound/soc/sdca/sdca_functions.c
index 2d5d20e23e3c..3e1df30f5d60 100644
--- a/sound/soc/sdca/sdca_functions.c
+++ b/sound/soc/sdca/sdca_functions.c
@@ -779,6 +779,62 @@ find_sdca_control_datatype(const struct sdca_entity *entity,
 	}
 }
 
+static bool find_sdca_control_volatile(const struct sdca_entity *entity,
+				       const struct sdca_control *control)
+{
+	switch (control->mode) {
+	case SDCA_ACCESS_MODE_DC:
+		return false;
+	case SDCA_ACCESS_MODE_RO:
+	case SDCA_ACCESS_MODE_RW1S:
+	case SDCA_ACCESS_MODE_RW1C:
+		return true;
+	default:
+		break;
+	}
+
+	switch (SDCA_CTL_TYPE(entity->type, control->sel)) {
+	case SDCA_CTL_TYPE_S(XU, FDL_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(XU, FDL_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(XU, FDL_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(XU, FDL_STATUS):
+	case SDCA_CTL_TYPE_S(XU, FDL_HOST_REQUEST):
+	case SDCA_CTL_TYPE_S(SPE, AUTHTX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(SPE, AUTHTX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(SPE, AUTHTX_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(SPE, AUTHRX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(SPE, AUTHRX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(SPE, AUTHRX_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(MFPU, AE_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(MFPU, AE_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(MFPU, AE_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(SMPU, HIST_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(SMPU, HIST_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(SMPU, HIST_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(SMPU, DTODTX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(SMPU, DTODTX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(SMPU, DTODTX_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(SMPU, DTODRX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(SMPU, DTODRX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(SMPU, DTODRX_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(SAPU, DTODTX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(SAPU, DTODTX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(SAPU, DTODTX_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(SAPU, DTODRX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(SAPU, DTODRX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(SAPU, DTODRX_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(HIDE, HIDTX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(HIDE, HIDTX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(HIDE, HIDTX_MESSAGELENGTH):
+	case SDCA_CTL_TYPE_S(HIDE, HIDRX_CURRENTOWNER):
+	case SDCA_CTL_TYPE_S(HIDE, HIDRX_MESSAGEOFFSET):
+	case SDCA_CTL_TYPE_S(HIDE, HIDRX_MESSAGELENGTH):
+		return true;
+	default:
+		return false;
+	}
+}
+
 static int find_sdca_control_range(struct device *dev,
 				   struct fwnode_handle *control_node,
 				   struct sdca_control_range *range)
@@ -930,6 +986,8 @@ static int find_sdca_entity_control(struct device *dev, struct sdca_entity *enti
 		break;
 	}
 
+	control->is_volatile = find_sdca_control_volatile(entity, control);
+
 	ret = find_sdca_control_range(dev, control_node, &control->range);
 	if (ret) {
 		dev_err(dev, "%s: control %#x: range missing: %d\n",
diff --git a/sound/soc/sdca/sdca_regmap.c b/sound/soc/sdca/sdca_regmap.c
index 72f893e00ff5..8fa138fca00f 100644
--- a/sound/soc/sdca/sdca_regmap.c
+++ b/sound/soc/sdca/sdca_regmap.c
@@ -147,14 +147,7 @@ bool sdca_regmap_volatile(struct sdca_function_data *function, unsigned int reg)
 	if (!control)
 		return false;
 
-	switch (control->mode) {
-	case SDCA_ACCESS_MODE_RO:
-	case SDCA_ACCESS_MODE_RW1S:
-	case SDCA_ACCESS_MODE_RW1C:
-		return true;
-	default:
-		return false;
-	}
+	return control->is_volatile;
 }
 EXPORT_SYMBOL_NS(sdca_regmap_volatile, "SND_SOC_SDCA");