Read _SUB from ACPI to be able to identify firmware

PATCH Superseded Stefan Binding 3 participants 7 messages Jun 22, 2022 – Jun 23, 2022

Subsystems (4)

Sound ACPI ASoC Cirrus Logic audio codecs

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Stefan Binding

author

2022-06-22 13:08 UTC #0 lore raw

cover 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.

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       | 26 ++++++++++++++++++++++++++
 include/linux/acpi.h       |  8 ++++++++
 sound/soc/codecs/cs35l41.c | 27 +++++++++++++++++++++++++++
 3 files changed, 61 insertions(+)

Signature · 1 line

2.25.1

Stefan Binding

author

2022-06-22 13:08 UTC #1 lore raw

PATCH 1/2 ACPI: utils: Add api to read _SUB from ACPI

Add a wrapper function to read the _SUB string from ACPI.

Signed-off-by Stefan Binding <[email protected]>

---
 drivers/acpi/utils.c | 26 ++++++++++++++++++++++++++
 include/linux/acpi.h |  8 ++++++++
 2 files changed, 34 insertions(+)

drivers/acpi/utils.c +26 -0

index 3a9773a09e19..5d1bdb79e372 100644
@@ -291,6 +291,32 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr)
 }
 EXPORT_SYMBOL(acpi_get_local_address);
 
+int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	acpi_status status;
+	int ret;
+
+	status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
+	if (!ACPI_SUCCESS(status)) {
+		acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
+		return -ENOENT;
+	}
+
+	obj = buffer.pointer;
+	if (obj->type == ACPI_TYPE_STRING) {
+		ret = strscpy(sub, obj->string.pointer, size);
+	} else {
+		acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
+		ret = -EINVAL;
+	}
+	acpi_os_free(buffer.pointer);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_get_sub);
+
 acpi_status
 acpi_evaluate_reference(acpi_handle handle,
 			acpi_string pathname,

include/linux/acpi.h +8 -0

index 4f82a5bc6d98..9bf18adf5920 100644
@@ -21,6 +21,8 @@
 #endif
 #include <acpi/acpi.h>
 
+#define ACPI_MAX_SUB_BUF_SIZE	9
+
 #ifdef	CONFIG_ACPI
 
 #include <linux/list.h>

@@ -762,6 +764,7 @@ static inline u64 acpi_arch_get_root_pointer(void)
 #endif
 
 int acpi_get_local_address(acpi_handle handle, u32 *addr);
+int acpi_get_sub(acpi_handle handle, char *sub, size_t size);
 
 #else	/* !CONFIG_ACPI */

@@ -1023,6 +1026,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr)
 	return -ENODEV;
 }
 
+static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
+{
+	return -ENODEV;
+}
+
 static inline int acpi_register_wakeup_handler(int wake_irq,
 	bool (*wakeup)(void *context), void *context)
 {

Signature · 1 line

2.25.1

Rafael J. Wysocki

maintainer

2022-06-22 13:19 UTC #2 lore raw

Re: [PATCH v1 1/2] ACPI: utils: Add api to read _SUB from ACPI

Quoted 14 lines · Stefan Binding

Add a wrapper function to read the _SUB string from ACPI.
Signed-off-by Stefan Binding <[email protected]>
---
 drivers/acpi/utils.c | 26 ++++++++++++++++++++++++++
 include/linux/acpi.h |  8 ++++++++
 2 files changed, 34 insertions(+)
drivers/acpi/utils.c +0 -0
index 3a9773a09e19..5d1bdb79e372 100644

drivers/acpi/utils.c int acpi_get_local_address(acpi_handle handle, u32 *addr) · line 294

Quoted 4 lines

drivers/acpi/utils.c +1 -0

@@ -291,6 +291,32 @@ int acpi_get_local_address(acpi_handle handle, u32 *addr)
 }
 EXPORT_SYMBOL(acpi_get_local_address);
 
+int acpi_get_sub(acpi_handle handle, char *sub, size_t size)

I'd call it acpi_get_subsystem_id().

drivers/acpi/utils.c int acpi_get_local_address(acpi_handle handle, u32 *addr) · line 302

Quoted 8 lines

drivers/acpi/utils.c +8 -0

+{
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+       union acpi_object *obj;
+       acpi_status status;
+       int ret;
+
+       status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
+       if (!ACPI_SUCCESS(status)) {

Typically, ACPI_FAILURE() is used in checks like this.

drivers/acpi/utils.c int acpi_get_local_address(acpi_handle handle, u32 *addr) · line 303

Quoted 1 line

drivers/acpi/utils.c +1 -0

+               acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);

It would be enough to say "_SUB evaluation failed".

drivers/acpi/utils.c int acpi_get_local_address(acpi_handle handle, u32 *addr) · line 304

Quoted 1 line

drivers/acpi/utils.c +1 -0

+               return -ENOENT;

Why not use -ENODATA here?

drivers/acpi/utils.c int acpi_get_local_address(acpi_handle handle, u32 *addr) · line 309

Quoted 5 lines

drivers/acpi/utils.c +5 -0

+       }
+
+       obj = buffer.pointer;
+       if (obj->type == ACPI_TYPE_STRING) {
+               ret = strscpy(sub, obj->string.pointer, size);

It may be simpler to allocate the memory here so that callers don't have to worry about it.

Also, this is expected to be a proper device ID, not just a string, so maybe some validation checks could be made here?

Quoted 47 lines

drivers/acpi/utils.c +10 -0

+       } else {
+               acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
+               ret = -EINVAL;
+       }
+       acpi_os_free(buffer.pointer);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_get_sub);
+
 acpi_status
 acpi_evaluate_reference(acpi_handle handle,
                        acpi_string pathname,

include/linux/acpi.h +8 -1

index 4f82a5bc6d98..9bf18adf5920 100644
@@ -21,6 +21,8 @@
 #endif
 #include <acpi/acpi.h>
 
+#define ACPI_MAX_SUB_BUF_SIZE  9
+
 #ifdef CONFIG_ACPI
 
 #include <linux/list.h>

@@ -762,6 +764,7 @@ static inline u64 acpi_arch_get_root_pointer(void)
 #endif
 
 int acpi_get_local_address(acpi_handle handle, u32 *addr);
+int acpi_get_sub(acpi_handle handle, char *sub, size_t size);
 
 #else  /* !CONFIG_ACPI */

@@ -1023,6 +1026,11 @@ static inline int acpi_get_local_address(acpi_handle handle, u32 *addr)
        return -ENODEV;
 }
 
+static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
+{
+       return -ENODEV;
+}
+
 static inline int acpi_register_wakeup_handler(int wake_irq,
        bool (*wakeup)(void *context), void *context)
 {
--

kernel test robot

build bot

2022-06-22 21:01 UTC #3 lore raw

Re: [PATCH v1 1/2] ACPI: utils: Add api to read _SUB from ACPI

In reply to Stefan Binding

Thank you for the patch! Yet something to improve:

Hi Stefan,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on broonie-sound/for-next linus/master v5.19-rc3 next-20220622] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: powerpc-buildonly-randconfig-r002-20220622 (https://download.01.org/0day-ci/archive/20220623/[email protected]/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 8b8d126598ce7bd5243da7f94f69fa1104288bee)

reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross
# install powerpc cross compiling tool for clang build
# apt-get install binutils-powerpc-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/97b928a895ce3105296f0036393bb9ee04f11ae4
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004 git checkout 97b928a895ce3105296f0036393bb9ee04f11ae4
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/

If you fix the issue, kindly add following tag where applicable

Reported-by kernel test robot <[email protected]>

All errors (new ones prefixed by >>):

In file included from arch/powerpc/kernel/traps.c:32:
In file included from include/linux/backlight.h:13:
In file included from include/linux/fb.h:7:
In file included from include/uapi/linux/fb.h:6:
In file included from include/linux/i2c.h:13:

>> include/linux/acpi.h:1029:12: error: unused function 'acpi_get_sub' [-Werror,-Wunused-function]
   static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
              ^

1 error generated.

vim +/acpi_get_sub +1029 include/linux/acpi.h

1028

> 1029	static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)

1030 {
1031 return -ENODEV;
1032 }
1033

Signature · 2 lines

0-DAY CI Kernel Test Service
https://01.org/lkp

kernel test robot

build bot

2022-06-22 21:11 UTC #4 lore raw

Re: [PATCH v1 1/2] ACPI: utils: Add api to read _SUB from ACPI

In reply to Stefan Binding

Thank you for the patch! Yet something to improve:

Hi Stefan,

Thank you for the patch! Yet something to improve:

url:    https://github.com/intel-lab-lkp/linux/commits/Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: powerpc-pasemi_defconfig (https://download.01.org/0day-ci/archive/20220623/[email protected]/config)
compiler: powerpc-linux-gcc (GCC) 11.3.0

reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/97b928a895ce3105296f0036393bb9ee04f11ae4
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004 git checkout 97b928a895ce3105296f0036393bb9ee04f11ae4
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable

Reported-by kernel test robot <[email protected]>

All errors (new ones prefixed by >>):

In file included from include/linux/i2c.h:13,
from include/uapi/linux/fb.h:6, from include/linux/fb.h:7, from include/linux/backlight.h:13, from arch/powerpc/kernel/traps.c:32:

>> include/linux/acpi.h:1029:12: error: 'acpi_get_sub' defined but not used [-Werror=unused-function]

1029 | static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)
| ^~~~~~~~~~~~
cc1: all warnings being treated as errors

vim +/acpi_get_sub +1029 include/linux/acpi.h

1028

> 1029	static int acpi_get_sub(acpi_handle handle, char *sub, size_t size)

1030 {
1031 return -ENODEV;
1032 }
1033

Signature · 2 lines

0-DAY CI Kernel Test Service
https://01.org/lkp

Stefan Binding

author

2022-06-22 13:08 UTC #5 lore raw

PATCH 2/2 ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware

In reply to Stefan Binding

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 <[email protected]>

---
 sound/soc/codecs/cs35l41.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

sound/soc/codecs/cs35l41.c +27 -0

index 8766e19d85f1..5df04a2ab5a3 100644
@@ -6,6 +6,7 @@
 //
 // Author: David Rhodes <[email protected]>
 
+#include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/init.h>

@@ -1142,6 +1143,28 @@ static int cs35l41_dsp_init(struct cs35l41_private *cs35l41)
 	return ret;
 }
 
+static int cs35l41_probe_acpi(struct cs35l41_private *cs35l41)
+{
+	struct acpi_device *adev;
+	int ret;
+	char sub[ACPI_MAX_SUB_BUF_SIZE];
+
+	adev = ACPI_COMPANION(cs35l41->dev);
+	/* If there is no ACPI_COMPANION, there is no ACPI for this system, return 0 */
+	if (!adev)
+		return 0;
+
+	ret = acpi_get_sub(adev->handle, sub, sizeof(sub));
+	if (ret < 0)
+		return ret;
+
+	cs35l41->dsp.system_name = devm_kstrdup(cs35l41->dev, sub, GFP_KERNEL);
+	if (!cs35l41->dsp.system_name)
+		return -ENOMEM;
+
+	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 +1293,10 @@ int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *
 		goto err;
 	}
 
+	ret = cs35l41_probe_acpi(cs35l41);
+	if (ret < 0)
+		goto err;
+
 	ret = cs35l41_dsp_init(cs35l41);
 	if (ret < 0)
 		goto err;

Signature · 1 line

2.25.1

kernel test robot

build bot

2022-06-23 04:03 UTC #6 lore raw

Re: [PATCH v1 2/2] ASoC: cs35l41: Read System Name from ACPI _SUB to identify firmware

Thank you for the patch! Yet something to improve:

Hi Stefan,

Thank you for the patch! Yet something to improve:

url:    https://github.com/intel-lab-lkp/linux/commits/Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: sparc64-randconfig-r002-20220622 (https://download.01.org/0day-ci/archive/20220623/[email protected]/config)
compiler: sparc64-linux-gcc (GCC) 11.3.0

reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/338eadc59e88d60759ea445011a6537222b233e3
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Stefan-Binding/Read-_SUB-from-ACPI-to-be-able-to-identify-firmware/20220622-211004 git checkout 338eadc59e88d60759ea445011a6537222b233e3
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=sparc64 SHELL=/bin/bash sound/soc/codecs/

If you fix the issue, kindly add following tag where applicable

Reported-by kernel test robot <[email protected]>

All errors (new ones prefixed by >>):

sound/soc/codecs/cs35l41.c: In function 'cs35l41_probe_acpi':

>> sound/soc/codecs/cs35l41.c:1157:32: error: invalid use of undefined type 'struct acpi_device'
    1157 |         ret = acpi_get_sub(adev->handle, sub, sizeof(sub));
         |                                ^~

vim +1157 sound/soc/codecs/cs35l41.c

1145
1146 static int cs35l41_probe_acpi(struct cs35l41_private *cs35l41)
1147 {
1148 struct acpi_device *adev;
1149 int ret;
1150 char sub[ACPI_MAX_SUB_BUF_SIZE];
1151
1152 adev = ACPI_COMPANION(cs35l41->dev);
1153 /* If there is no ACPI_COMPANION, there is no ACPI for this system, return 0 */
1154 if (!adev)
1155 return 0;
1156

> 1157		ret = acpi_get_sub(adev->handle, sub, sizeof(sub));

1158 if (ret < 0)
1159 return ret;
1160
1161 cs35l41->dsp.system_name = devm_kstrdup(cs35l41->dev, sub, GFP_KERNEL);
1162 if (!cs35l41->dsp.system_name)
1163 return -ENOMEM;
1164
1165 return 0;
1166 }
1167

Signature · 2 lines

0-DAY CI Kernel Test Service
https://01.org/lkp