[PATCH v5 0/2] Read _SUB from ACPI to be able to identify firmware
CS35L41 has a DSP which is able to run firmware, as well as a tuning file. Different systems may want to use different firmwares and tuning files, and some firmwares/tunings may not be compatible with other systems. To allow a system to select the correct fimware/tuning, we can read an _SUB from the ACPI. This _SUB can then be used to uniquely identify the system in the firmware/tuning file name.
Add a helper function which reads the _SUB, so this can be used by other parts in the future. Add support inside the CS35L41 ASoC driver to read this _SUB, and save it appropriately.
Changes since v4: - Rename function
Changes since v3: - Fix 32 bit format string warning
Changes since v2: - Fix error in function prototype
Changes since v1: - Add length validation for SSID String - Rename API - Allocate memory inside API - Use ACPI_HANDLE macro instead of ACPI_COMPANION - Improve error handling
Stefan Binding (2): ACPI: utils: Add api to read _SUB from ACPI ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware
drivers/acpi/utils.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 6 ++++++ sound/soc/codecs/cs35l41.c | 24 ++++++++++++++++++++++++ 3 files changed, 68 insertions(+)
Add a wrapper function to read the _SUB string from ACPI.
Signed-off-by: Stefan Binding sbinding@opensource.cirrus.com --- drivers/acpi/utils.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 6 ++++++ 2 files changed, 44 insertions(+)
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c index 3a9773a09e19..394954f4b6ef 100644 --- a/drivers/acpi/utils.c +++ b/drivers/acpi/utils.c @@ -291,6 +291,44 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr) } EXPORT_SYMBOL(acpi_get_local_address);
+#define ACPI_MAX_SUB_BUF_SIZE 9 + +const char *acpi_get_subsystem_id(acpi_handle handle) +{ + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *obj; + acpi_status status; + const char *sub; + + status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer); + if (ACPI_FAILURE(status)) { + acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status); + return ERR_PTR(-ENODATA); + } + + obj = buffer.pointer; + if (obj->type == ACPI_TYPE_STRING) { + if (strlen(obj->string.pointer) < ACPI_MAX_SUB_BUF_SIZE && + strlen(obj->string.pointer) > 0) { + sub = kstrdup(obj->string.pointer, GFP_KERNEL); + if (!sub) + sub = ERR_PTR(-ENOMEM); + } else { + acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", + strlen(obj->string.pointer)); + sub = ERR_PTR(-EINVAL); + } + } else { + acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n"); + sub = ERR_PTR(-EINVAL); + } + + acpi_os_free(buffer.pointer); + + return sub; +} +EXPORT_SYMBOL_GPL(acpi_get_subsystem_id); + acpi_status acpi_evaluate_reference(acpi_handle handle, acpi_string pathname, diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 7b96a8bff6d2..7651198ad6f5 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -762,6 +762,7 @@ static inline u64 acpi_arch_get_root_pointer(void) #endif
int acpi_get_local_address(acpi_handle handle, u32 *addr); +const char *acpi_get_subsystem_id(acpi_handle handle);
#else /* !CONFIG_ACPI */
@@ -1023,6 +1024,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr) return -ENODEV; }
+static inline const char *acpi_get_subsystem_id(acpi_handle handle) +{ + return ERR_PTR(-ENODEV); +} + static inline int acpi_register_wakeup_handler(int wake_irq, bool (*wakeup)(void *context), void *context) {
On Thu, Jun 30, 2022 at 5:01 PM Stefan Binding sbinding@opensource.cirrus.com wrote:
Add a wrapper function to read the _SUB string from ACPI.
Signed-off-by: Stefan Binding sbinding@opensource.cirrus.com
drivers/acpi/utils.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 6 ++++++ 2 files changed, 44 insertions(+)
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c index 3a9773a09e19..394954f4b6ef 100644 --- a/drivers/acpi/utils.c +++ b/drivers/acpi/utils.c @@ -291,6 +291,44 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr) } EXPORT_SYMBOL(acpi_get_local_address);
+#define ACPI_MAX_SUB_BUF_SIZE 9
+const char *acpi_get_subsystem_id(acpi_handle handle) +{
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };union acpi_object *obj;acpi_status status;const char *sub;status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);if (ACPI_FAILURE(status)) {acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);return ERR_PTR(-ENODATA);}obj = buffer.pointer;if (obj->type == ACPI_TYPE_STRING) {if (strlen(obj->string.pointer) < ACPI_MAX_SUB_BUF_SIZE &&strlen(obj->string.pointer) > 0) {sub = kstrdup(obj->string.pointer, GFP_KERNEL);if (!sub)sub = ERR_PTR(-ENOMEM);
The error codes below are somewhat questionable.
} else {acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n",strlen(obj->string.pointer));sub = ERR_PTR(-EINVAL);
This is as good as failure, so why not use -ENODATA here?
}} else {acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");sub = ERR_PTR(-EINVAL);
Likewise.
}acpi_os_free(buffer.pointer);return sub;+} +EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
acpi_status acpi_evaluate_reference(acpi_handle handle, acpi_string pathname, diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 7b96a8bff6d2..7651198ad6f5 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -762,6 +762,7 @@ static inline u64 acpi_arch_get_root_pointer(void) #endif
int acpi_get_local_address(acpi_handle handle, u32 *addr); +const char *acpi_get_subsystem_id(acpi_handle handle);
#else /* !CONFIG_ACPI */
@@ -1023,6 +1024,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr) return -ENODEV; }
+static inline const char *acpi_get_subsystem_id(acpi_handle handle) +{
return ERR_PTR(-ENODEV);+}
static inline int acpi_register_wakeup_handler(int wake_irq, bool (*wakeup)(void *context), void *context) { -- 2.25.1
On Thu, Jun 30, 2022 at 5:17 PM Stefan Binding sbinding@opensource.cirrus.com wrote:
Add a wrapper function to read the _SUB string from ACPI.
...
if (obj->type == ACPI_TYPE_STRING) {if (strlen(obj->string.pointer) < ACPI_MAX_SUB_BUF_SIZE &&strlen(obj->string.pointer) > 0) {sub = kstrdup(obj->string.pointer, GFP_KERNEL);if (!sub)sub = ERR_PTR(-ENOMEM);} else {acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n",strlen(obj->string.pointer));
Three times to evaluate strlen()... Can we do better, please?
sub = ERR_PTR(-EINVAL);}} else {acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");sub = ERR_PTR(-EINVAL);}
When loading firmware, wm_adsp uses a number of parameters to determine the path of the firmware and tuning files to load. One of these parameters is system_name. Add support in cs35l41 to read this system name from the ACPI _SUB ID in order to uniquely identify the firmware and tuning mapped to a particular system.
Signed-off-by: Stefan Binding sbinding@opensource.cirrus.com --- sound/soc/codecs/cs35l41.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/sound/soc/codecs/cs35l41.c b/sound/soc/codecs/cs35l41.c index 8766e19d85f1..d70469686699 100644 --- a/sound/soc/codecs/cs35l41.c +++ b/sound/soc/codecs/cs35l41.c @@ -6,6 +6,7 @@ // // Author: David Rhodes david.rhodes@cirrus.com
+#include <linux/acpi.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/init.h> @@ -1142,6 +1143,24 @@ static int cs35l41_dsp_init(struct cs35l41_private *cs35l41) return ret; }
+static int cs35l41_acpi_get_name(struct cs35l41_private *cs35l41) +{ + acpi_handle handle = ACPI_HANDLE(cs35l41->dev); + const char *sub; + + /* If there is no ACPI_HANDLE, there is no ACPI for this system, return 0 */ + if (!handle) + return 0; + + sub = acpi_get_subsystem_id(handle); + if (IS_ERR(sub)) + return PTR_ERR(sub); + + cs35l41->dsp.system_name = sub; + dev_dbg(cs35l41->dev, "Susystem ID: %s\n", cs35l41->dsp.system_name); + return 0; +} + int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *hw_cfg) { u32 regid, reg_revid, i, mtl_revid, int_status, chipid_match; @@ -1270,6 +1289,10 @@ int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg * goto err; }
+ ret = cs35l41_acpi_get_name(cs35l41); + if (ret < 0) + goto err; + ret = cs35l41_dsp_init(cs35l41); if (ret < 0) goto err; @@ -1316,6 +1339,7 @@ void cs35l41_remove(struct cs35l41_private *cs35l41) pm_runtime_disable(cs35l41->dev);
regmap_write(cs35l41->regmap, CS35L41_IRQ1_MASK1, 0xFFFFFFFF); + kfree(cs35l41->dsp.system_name); wm_adsp2_remove(&cs35l41->dsp); cs35l41_safe_reset(cs35l41->regmap, cs35l41->hw_cfg.bst_type);
On 6/30/22 10:01, Stefan Binding wrote:
When loading firmware, wm_adsp uses a number of parameters to determine the path of the firmware and tuning files to load. One of these parameters is system_name. Add support in cs35l41 to read this system name from the ACPI _SUB ID in order to uniquely identify the firmware and tuning mapped to a particular system.
It's my understanding that the _SUB method is optional, not required. It may be wise to plan for a fallback, e.g to use DMI quirks or other identifiers, no?
If it's used quite widely, then it may be a good thing to add to 'alsa-info'.
Signed-off-by: Stefan Binding sbinding@opensource.cirrus.com
sound/soc/codecs/cs35l41.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/sound/soc/codecs/cs35l41.c b/sound/soc/codecs/cs35l41.c index 8766e19d85f1..d70469686699 100644 --- a/sound/soc/codecs/cs35l41.c +++ b/sound/soc/codecs/cs35l41.c @@ -6,6 +6,7 @@ // // Author: David Rhodes david.rhodes@cirrus.com
+#include <linux/acpi.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/init.h> @@ -1142,6 +1143,24 @@ static int cs35l41_dsp_init(struct cs35l41_private *cs35l41) return ret; }
+static int cs35l41_acpi_get_name(struct cs35l41_private *cs35l41) +{
- acpi_handle handle = ACPI_HANDLE(cs35l41->dev);
- const char *sub;
- /* If there is no ACPI_HANDLE, there is no ACPI for this system, return 0 */
- if (!handle)
return 0;- sub = acpi_get_subsystem_id(handle);
- if (IS_ERR(sub))
return PTR_ERR(sub);- cs35l41->dsp.system_name = sub;
- dev_dbg(cs35l41->dev, "Susystem ID: %s\n", cs35l41->dsp.system_name);
Typo: Subsystem
- return 0;
+}
int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *hw_cfg) { u32 regid, reg_revid, i, mtl_revid, int_status, chipid_match; @@ -1270,6 +1289,10 @@ int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg * goto err; }
- ret = cs35l41_acpi_get_name(cs35l41);
- if (ret < 0)
goto err;- ret = cs35l41_dsp_init(cs35l41); if (ret < 0) goto err;
@@ -1316,6 +1339,7 @@ void cs35l41_remove(struct cs35l41_private *cs35l41) pm_runtime_disable(cs35l41->dev);
regmap_write(cs35l41->regmap, CS35L41_IRQ1_MASK1, 0xFFFFFFFF);
- kfree(cs35l41->dsp.system_name); wm_adsp2_remove(&cs35l41->dsp); cs35l41_safe_reset(cs35l41->regmap, cs35l41->hw_cfg.bst_type);
On Thu, Jun 30, 2022 at 01:35:05PM -0500, Pierre-Louis Bossart wrote:
It's my understanding that the _SUB method is optional, not required. It may be wise to plan for a fallback, e.g to use DMI quirks or other identifiers, no?
Presumably the fallback would go into cs35l41_acpi_get_name()?
On 6/30/22 14:34, Mark Brown wrote:
On Thu, Jun 30, 2022 at 01:35:05PM -0500, Pierre-Louis Bossart wrote:
It's my understanding that the _SUB method is optional, not required. It may be wise to plan for a fallback, e.g to use DMI quirks or other identifiers, no?
Presumably the fallback would go into cs35l41_acpi_get_name()?
That's what I had in mind, if this _SUB does not exist then you could use something else instead of returning -ENODATA;
+ sub = acpi_get_subsystem_id(handle); + if (IS_ERR(sub)) + return PTR_ERR(sub); + + cs35l41->dsp.system_name = sub;
participants (5)
-
Andy Shevchenko -
Mark Brown -
Pierre-Louis Bossart -
Rafael J. Wysocki -
Stefan Binding