* [PATCH v2 1/2] ASoC: dt-bindings: cirrus,cs35l41: Document the cirrus,subsystem-id property
2025-09-12 15:47 [PATCH v2 0/2] Support reading Subsystem ID from Device Tree Stefan Binding
@ 2025-09-12 15:47 ` Stefan Binding
2025-09-13 13:48 ` Krzysztof Kozlowski
2025-09-12 15:47 ` [PATCH v2 2/2] ASoC: cs35l41: Fallback to reading Subsystem ID property if not ACPI Stefan Binding
1 sibling, 1 reply; 4+ messages in thread
From: Stefan Binding @ 2025-09-12 15:47 UTC (permalink / raw)
To: Mark Brown, Rob Herring, Krzysztof Kozlowski, Conor Dooley
Cc: linux-sound, devicetree, linux-kernel, patches, Stefan Binding
Add new property: cirrus,subsystem-id
This new property is used to uniquely identify the system if device
tree is used, to allow the driver to select the correct firmware and
tuning for the system.
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
---
Documentation/devicetree/bindings/sound/cirrus,cs35l41.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/cirrus,cs35l41.yaml b/Documentation/devicetree/bindings/sound/cirrus,cs35l41.yaml
index 14dea1feefc5..e6cf2ebcd777 100644
--- a/Documentation/devicetree/bindings/sound/cirrus,cs35l41.yaml
+++ b/Documentation/devicetree/bindings/sound/cirrus,cs35l41.yaml
@@ -151,6 +151,12 @@ properties:
minimum: 0
maximum: 5
+ cirrus,subsystem-id:
+ $ref: /schemas/types.yaml#/definitions/string
+ description:
+ Subsystem ID. If this property is present, it sets the system name,
+ used to identify the firmware and tuning to load.
+
required:
- compatible
- reg
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2 2/2] ASoC: cs35l41: Fallback to reading Subsystem ID property if not ACPI
2025-09-12 15:47 [PATCH v2 0/2] Support reading Subsystem ID from Device Tree Stefan Binding
2025-09-12 15:47 ` [PATCH v2 1/2] ASoC: dt-bindings: cirrus,cs35l41: Document the cirrus,subsystem-id property Stefan Binding
@ 2025-09-12 15:47 ` Stefan Binding
1 sibling, 0 replies; 4+ messages in thread
From: Stefan Binding @ 2025-09-12 15:47 UTC (permalink / raw)
To: Mark Brown, Rob Herring, Krzysztof Kozlowski, Conor Dooley
Cc: linux-sound, devicetree, linux-kernel, patches, Stefan Binding
If ACPI is not used, then there is currently no way of reading a
Subsystem ID property used for a system name to uniquely identify
the system in order to load the correct firmware and tuning.
Add a new property which can be read from device tree to be able to set
the system name.
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
---
sound/soc/codecs/cs35l41.c | 77 ++++++++++++++++++++++----------------
1 file changed, 44 insertions(+), 33 deletions(-)
diff --git a/sound/soc/codecs/cs35l41.c b/sound/soc/codecs/cs35l41.c
index 224d65987a8d..d7e3d89de652 100644
--- a/sound/soc/codecs/cs35l41.c
+++ b/sound/soc/codecs/cs35l41.c
@@ -7,6 +7,7 @@
// Author: David Rhodes <david.rhodes@cirrus.com>
#include <linux/acpi.h>
+#include <acpi/acpi_bus.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -1147,45 +1148,55 @@ static int cs35l41_dsp_init(struct cs35l41_private *cs35l41)
return ret;
}
-#ifdef CONFIG_ACPI
-static int cs35l41_acpi_get_name(struct cs35l41_private *cs35l41)
+static int cs35l41_get_system_name(struct cs35l41_private *cs35l41)
{
struct acpi_device *adev = ACPI_COMPANION(cs35l41->dev);
- acpi_handle handle = acpi_device_handle(adev);
- const char *hid;
- const char *sub;
-
- /* If there is no acpi_device, there is no ACPI for this system, return 0 */
- if (!adev)
- return 0;
+ const char *sub = NULL;
+ const char *tmp;
+ int ret = 0;
- sub = acpi_get_subsystem_id(handle);
- if (IS_ERR(sub)) {
- /* If no _SUB, fallback to _HID, otherwise fail */
- if (PTR_ERR(sub) == -ENODATA) {
- hid = acpi_device_hid(adev);
- /* If dummy hid, return 0 and fallback to legacy firmware path */
- if (!strcmp(hid, "device"))
- return 0;
- sub = kstrdup(hid, GFP_KERNEL);
- if (!sub)
- sub = ERR_PTR(-ENOMEM);
-
- } else
- return PTR_ERR(sub);
+ /* If there is no acpi_device, there is no ACPI for this system, skip checking ACPI */
+ if (adev) {
+ acpi_handle handle = acpi_device_handle(adev);
+
+ sub = acpi_get_subsystem_id(handle);
+ ret = PTR_ERR(sub);
+ if (ret) {
+ sub = NULL;
+ /* If no _SUB, fallback to _HID, otherwise fail */
+ if (ret == -ENODATA) {
+ tmp = acpi_device_hid(adev);
+ /* If dummy hid, return 0 and fallback to legacy firmware path */
+ if (!strcmp(tmp, "device")) {
+ ret = 0;
+ goto err;
+ }
+ sub = kstrdup(tmp, GFP_KERNEL);
+ if (!sub) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ }
+ }
+ } else {
+ if (!device_property_read_string(cs35l41->dev, "cirrus,subsystem-id", &tmp)) {
+ sub = kstrdup(tmp, GFP_KERNEL);
+ if (!sub) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ }
}
- cs35l41->dsp.system_name = sub;
- dev_dbg(cs35l41->dev, "Subsystem ID: %s\n", cs35l41->dsp.system_name);
+err:
+ if (sub) {
+ cs35l41->dsp.system_name = sub;
+ dev_info(cs35l41->dev, "Subsystem ID: %s\n", cs35l41->dsp.system_name);
+ } else
+ dev_warn(cs35l41->dev, "Subsystem ID not found\n");
- return 0;
-}
-#else
-static int cs35l41_acpi_get_name(struct cs35l41_private *cs35l41)
-{
- return 0;
+ return ret;
}
-#endif /* CONFIG_ACPI */
int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *hw_cfg)
{
@@ -1317,7 +1328,7 @@ int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *
goto err;
}
- ret = cs35l41_acpi_get_name(cs35l41);
+ ret = cs35l41_get_system_name(cs35l41);
if (ret < 0)
goto err;
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread