From eef375960210fdc1ec2786bddc91ff100444ffb8 Mon Sep 17 00:00:00 2001

From: Stefan Binding <sbinding@opensource.cirrus.com>

Date: Thu, 30 Jun 2022 01:23:27 +0100

Subject: [PATCH] ALSA: hda: cs35l41: Support reading subsystem id from ACPI

Git-commit: eef375960210fdc1ec2786bddc91ff100444ffb8

Patch-mainline: v6.0-rc1

References: bsc#1203699

On some laptop models, the ACPI contains the unique

Subsystem ID, and this value should be preferred

over the value from the HDA driver.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>

Signed-off-by: Vitaly Rodionov <vitalyr@opensource.cirrus.com>

Link: https://lore.kernel.org/r/20220630002335.366545-7-vitalyr@opensource.cirrus.com

Signed-off-by: Takashi Iwai <tiwai@suse.de>

---

 sound/pci/hda/cs35l41_hda.c | 36 ++++++++++++++++++++++++++++++++++++

 1 file changed, 36 insertions(+)

diff --git a/sound/pci/hda/cs35l41_hda.c b/sound/pci/hda/cs35l41_hda.c

index 25cb76437ba5..effb3ce95c00 100644

--- a/sound/pci/hda/cs35l41_hda.c

+++ b/sound/pci/hda/cs35l41_hda.c

@@ -544,6 +544,36 @@ static int cs35l41_hda_apply_properties(struct cs35l41_hda *cs35l41)

 	return cs35l41_hda_channel_map(cs35l41->dev, 0, NULL, 1, &hw_cfg->spk_pos);

 }

+static int cs35l41_get_acpi_sub_string(struct device *dev, struct acpi_device *adev,

+				       const char **subsysid)

+{

+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

+	union acpi_object *obj;

+	acpi_status status;

+	int ret = 0;

+

+	status = acpi_evaluate_object(adev->handle, "_SUB", NULL, &buffer);

+	if (ACPI_SUCCESS(status)) {

+		obj = buffer.pointer;

+		if (obj->type == ACPI_TYPE_STRING) {

+			*subsysid = devm_kstrdup(dev, obj->string.pointer, GFP_KERNEL);

+			if (*subsysid == NULL) {

+				dev_err(dev, "Cannot allocate Subsystem ID");

+				ret = -ENOMEM;

+			}

+		} else {

+			dev_warn(dev, "Warning ACPI _SUB did not return a string\n");

+			ret = -ENODEV;

+		}

+		acpi_os_free(buffer.pointer);

+	} else {

+		dev_dbg(dev, "Warning ACPI _SUB failed: %#x\n", status);

+		ret = -ENODEV;

+	}

+

+	return ret;

+}

+

 static int cs35l41_hda_read_acpi(struct cs35l41_hda *cs35l41, const char *hid, int id)

 {

 	struct cs35l41_hw_cfg *hw_cfg = &cs35l41->hw_cfg;

@@ -563,6 +593,12 @@ static int cs35l41_hda_read_acpi(struct cs35l41_hda *cs35l41, const char *hid, i

 	physdev = get_device(acpi_get_first_physical_node(adev));

 	acpi_dev_put(adev);

+	ret = cs35l41_get_acpi_sub_string(cs35l41->dev, adev, &cs35l41->acpi_subsystem_id);

+	if (ret)

+		dev_info(cs35l41->dev, "No Subsystem ID found in ACPI: %d", ret);

+	else

+		dev_dbg(cs35l41->dev, "Subsystem ID %s found", cs35l41->acpi_subsystem_id);

+

 	property = "cirrus,dev-index";

 	ret = device_property_count_u32(physdev, property);

 	if (ret <= 0)

-- 

2.35.3