4 files changed, 256 insertions, 0 deletions
diff --git a/sound/soc/sdca/Kconfig b/sound/soc/sdca/Kconfig
new file mode 100644
index 000000000000..07f6822fa614
--- /dev/null
+++ b/sound/soc/sdca/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config SND_SOC_SDCA
+	tristate "ASoC SDCA library"
+	depends on ACPI
+	help
+	  This option enables support for the MIPI SoundWire Device
+	  Class for Audio (SDCA).
+
+config SND_SOC_SDCA_OPTIONAL
+	def_tristate SND_SOC_SDCA || !SND_SOC_SDCA
diff --git a/sound/soc/sdca/Makefile b/sound/soc/sdca/Makefile
new file mode 100644
index 000000000000..c296bd5a0a7c
--- /dev/null
+++ b/sound/soc/sdca/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+snd-soc-sdca-objs	:= sdca_functions.o sdca_device.o
+
+obj-$(CONFIG_SND_SOC_SDCA)	+= snd-soc-sdca.o
diff --git a/sound/soc/sdca/sdca_device.c b/sound/soc/sdca/sdca_device.c
new file mode 100644
index 000000000000..c44dc21cb634
--- /dev/null
+++ b/sound/soc/sdca/sdca_device.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2024 Intel Corporation
+
+/*
+ * The MIPI SDCA specification is available for public downloads at
+ * https://www.mipi.org/mipi-sdca-v1-0-download
+ */
+
+#include <linux/acpi.h>
+#include <linux/soundwire/sdw.h>
+#include <sound/sdca.h>
+#include <sound/sdca_function.h>
+
+void sdca_lookup_interface_revision(struct sdw_slave *slave)
+{
+	struct fwnode_handle *fwnode = slave->dev.fwnode;
+
+	/*
+	 * if this property is not present, then the sdca_interface_revision will
+	 * remain zero, which will be considered as 'not defined' or 'invalid'.
+	 */
+	fwnode_property_read_u32(fwnode, "mipi-sdw-sdca-interface-revision",
+				 &slave->sdca_data.interface_revision);
+}
+EXPORT_SYMBOL_NS(sdca_lookup_interface_revision, SND_SOC_SDCA);
+
+static bool sdca_device_quirk_rt712_vb(struct sdw_slave *slave)
+{
+	struct sdw_slave_id *id = &slave->id;
+	int i;
+
+	/*
+	 * The RT712_VA relies on the v06r04 draft, and the
+	 * RT712_VB on a more recent v08r01 draft.
+	 */
+	if (slave->sdca_data.interface_revision < 0x0801)
+		return false;
+
+	if (id->mfg_id != 0x025d)
+		return false;
+
+	if (id->part_id != 0x712 &&
+	    id->part_id != 0x713 &&
+	    id->part_id != 0x716 &&
+	    id->part_id != 0x717)
+		return false;
+
+	for (i = 0; i < slave->sdca_data.num_functions; i++) {
+		if (slave->sdca_data.sdca_func[i].type ==
+		    SDCA_FUNCTION_TYPE_SMART_MIC)
+			return true;
+	}
+
+	return false;
+}
+
+bool sdca_device_quirk_match(struct sdw_slave *slave, enum sdca_quirk quirk)
+{
+	switch (quirk) {
+	case SDCA_QUIRKS_RT712_VB:
+		return sdca_device_quirk_rt712_vb(slave);
+	default:
+		break;
+	}
+	return false;
+}
+EXPORT_SYMBOL_NS(sdca_device_quirk_match, SND_SOC_SDCA);
diff --git a/sound/soc/sdca/sdca_functions.c b/sound/soc/sdca/sdca_functions.c
new file mode 100644
index 000000000000..a6ad57430dd4
--- /dev/null
+++ b/sound/soc/sdca/sdca_functions.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+// Copyright(c) 2024 Intel Corporation
+
+/*
+ * The MIPI SDCA specification is available for public downloads at
+ * https://www.mipi.org/mipi-sdca-v1-0-download
+ */
+
+#include <linux/acpi.h>
+#include <linux/soundwire/sdw.h>
+#include <sound/sdca.h>
+#include <sound/sdca_function.h>
+
+static int patch_sdca_function_type(struct device *dev,
+				    u32 interface_revision,
+				    u32 *function_type,
+				    const char **function_name)
+{
+	unsigned long function_type_patch = 0;
+
+	/*
+	 * Unfortunately early SDCA specifications used different indices for Functions,
+	 * for backwards compatibility we have to reorder the values found
+	 */
+	if (interface_revision >= 0x0801)
+		goto skip_early_draft_order;
+
+	switch (*function_type) {
+	case 1:
+		function_type_patch = SDCA_FUNCTION_TYPE_SMART_AMP;
+		break;
+	case 2:
+		function_type_patch = SDCA_FUNCTION_TYPE_SMART_MIC;
+		break;
+	case 3:
+		function_type_patch = SDCA_FUNCTION_TYPE_SPEAKER_MIC;
+		break;
+	case 4:
+		function_type_patch = SDCA_FUNCTION_TYPE_UAJ;
+		break;
+	case 5:
+		function_type_patch = SDCA_FUNCTION_TYPE_RJ;
+		break;
+	case 6:
+		function_type_patch = SDCA_FUNCTION_TYPE_HID;
+		break;
+	default:
+		dev_warn(dev, "%s: SDCA version %#x unsupported function type %d, skipped\n",
+			 __func__, interface_revision, *function_type);
+		return -EINVAL;
+	}
+
+skip_early_draft_order:
+	if (function_type_patch)
+		*function_type = function_type_patch;
+
+	/* now double-check the values */
+	switch (*function_type) {
+	case SDCA_FUNCTION_TYPE_SMART_AMP:
+		*function_name = SDCA_FUNCTION_TYPE_SMART_AMP_NAME;
+		break;
+	case SDCA_FUNCTION_TYPE_SMART_MIC:
+		*function_name = SDCA_FUNCTION_TYPE_SMART_MIC_NAME;
+		break;
+	case SDCA_FUNCTION_TYPE_UAJ:
+		*function_name = SDCA_FUNCTION_TYPE_UAJ_NAME;
+		break;
+	case SDCA_FUNCTION_TYPE_HID:
+		*function_name = SDCA_FUNCTION_TYPE_HID_NAME;
+		break;
+	case SDCA_FUNCTION_TYPE_SIMPLE_AMP:
+	case SDCA_FUNCTION_TYPE_SIMPLE_MIC:
+	case SDCA_FUNCTION_TYPE_SPEAKER_MIC:
+	case SDCA_FUNCTION_TYPE_RJ:
+	case SDCA_FUNCTION_TYPE_IMP_DEF:
+		dev_warn(dev, "%s: found unsupported SDCA function type %d, skipped\n",
+			 __func__, *function_type);
+		return -EINVAL;
+	default:
+		dev_err(dev, "%s: found invalid SDCA function type %d, skipped\n",
+			__func__, *function_type);
+		return -EINVAL;
+	}
+
+	dev_info(dev, "%s: found SDCA function %s (type %d)\n",
+		 __func__, *function_name, *function_type);
+
+	return 0;
+}
+
+static int find_sdca_function(struct acpi_device *adev, void *data)
+{
+	struct fwnode_handle *function_node = acpi_fwnode_handle(adev);
+	struct sdca_device_data *sdca_data = data;
+	struct device *dev = &adev->dev;
+	struct fwnode_handle *control5; /* used to identify function type */
+	const char *function_name;
+	u32 function_type;
+	int func_index;
+	u64 addr;
+	int ret;
+
+	if (sdca_data->num_functions >= SDCA_MAX_FUNCTION_COUNT) {
+		dev_err(dev, "%s: maximum number of functions exceeded\n", __func__);
+		return -EINVAL;
+	}
+
+	/*
+	 * The number of functions cannot exceed 8, we could use
+	 * acpi_get_local_address() but the value is stored as u64 so
+	 * we might as well avoid casts and intermediate levels
+	 */
+	ret = acpi_get_local_u64_address(adev->handle, &addr);
+	if (ret < 0)
+		return ret;
+
+	if (!addr) {
+		dev_err(dev, "%s: no addr\n", __func__);
+		return -ENODEV;
+	}
+
+	/*
+	 * Extracting the topology type for an SDCA function is a
+	 * convoluted process.
+	 * The Function type is only visible as a result of a read
+	 * from a control. In theory this would mean reading from the hardware,
+	 * but the SDCA/DisCo specs defined the notion of "DC value" - a constant
+	 * represented with a DSD subproperty.
+	 * Drivers have to query the properties for the control
+	 * SDCA_CONTROL_ENTITY_0_FUNCTION_TOPOLOGY (0x05)
+	 */
+	control5 = fwnode_get_named_child_node(function_node,
+					       "mipi-sdca-control-0x5-subproperties");
+	if (!control5)
+		return -ENODEV;
+
+	ret = fwnode_property_read_u32(control5, "mipi-sdca-control-dc-value",
+				       &function_type);
+
+	fwnode_handle_put(control5);
+
+	if (ret < 0) {
+		dev_err(dev, "%s: the function type can only be determined from ACPI information\n",
+			__func__);
+		return ret;
+	}
+
+	ret = patch_sdca_function_type(dev, sdca_data->interface_revision,
+				       &function_type, &function_name);
+	if (ret < 0)
+		return ret;
+
+	/* store results */
+	func_index = sdca_data->num_functions;
+	sdca_data->sdca_func[func_index].adr = addr;
+	sdca_data->sdca_func[func_index].type = function_type;
+	sdca_data->sdca_func[func_index].name = function_name;
+	sdca_data->num_functions++;
+
+	return 0;
+}
+
+void sdca_lookup_functions(struct sdw_slave *slave)
+{
+	struct device *dev = &slave->dev;
+	struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
+
+	acpi_dev_for_each_child(adev, find_sdca_function, &slave->sdca_data);
+}
+EXPORT_SYMBOL_NS(sdca_lookup_functions, SND_SOC_SDCA);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("SDCA library");