[PATCH v1 0/2] Add _TZD method for ACPI thermal

[PATCH v1 0/2] Add _TZD method for ACPI thermal

[Huisong Li]

This series is mainly used to support _TZD method for ACPI thermal so as
to directly know the devices associated with the thermal zone.
And fix a little issue for acpi_power_meter by the way.

Huisong Li (2):
  ACPI: thermal: Support for linking devices associated with the thermal
    zone
  hwmon: (acpi_power_meter) Fix fail to load module on platform without
    _PMD method

 drivers/acpi/thermal.c           | 114 ++++++++++++++++++++++++++++++-
 drivers/hwmon/acpi_power_meter.c |   3 +-
 2 files changed, 115 insertions(+), 2 deletions(-)

-- 
2.22.0

[PATCH v1 1/2] ACPI: thermal: Support for linking devices associated with the thermal zone

[Huisong Li]

As ACPI spec said, '_TZD' evaluates to a package of device names.
Each name corresponds to a device in the ACPI namespace that is
associated with the thermal zone. The temperature reported by the
thermal zone is roughly correspondent to that of each of the devices.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
---
 drivers/acpi/thermal.c | 114 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 113 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 78db38c7076e..398195a5d42f 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -119,6 +119,9 @@ struct acpi_thermal {
 	struct work_struct thermal_check_work;
 	struct mutex thermal_check_lock;
 	refcount_t thermal_check_count;
+	int num_domain_devices;
+	struct acpi_device **domain_devices;
+	struct kobject *holders_dir;
 };
 
 /* --------------------------------------------------------------------------
@@ -589,6 +592,103 @@ static const struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 	.critical = acpi_thermal_zone_device_critical,
 };
 
+static void acpi_thermal_remove_domain_devices(struct acpi_thermal *tz)
+{
+	int i;
+
+	if (!tz->num_domain_devices)
+		return;
+
+	for (i = 0; i < tz->num_domain_devices; i++) {
+		struct acpi_device *obj = tz->domain_devices[i];
+
+		if (!obj)
+			continue;
+
+		sysfs_remove_link(tz->holders_dir,
+				  kobject_name(&obj->dev.kobj));
+		acpi_dev_put(obj);
+	}
+
+	kfree(tz->domain_devices);
+	kobject_put(tz->holders_dir);
+	tz->num_domain_devices = 0;
+}
+
+static int acpi_thermal_read_domain_devices(struct acpi_thermal *tz)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *pss;
+	acpi_status status;
+	int ret = 0;
+	int i;
+
+	status = acpi_evaluate_object(tz->device->handle, "_TZD", NULL,
+				      &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_evaluation_failure_warn(tz->device->handle, "_TZD",
+					     status);
+		return -ENODEV;
+	}
+
+	pss = buffer.pointer;
+	if (!pss ||
+	    pss->type != ACPI_TYPE_PACKAGE) {
+		dev_err(&tz->device->dev, "Thermal zone invalid _TZD data\n");
+		ret = -EFAULT;
+		goto end;
+	}
+
+	if (!pss->package.count)
+		goto end;
+
+	tz->domain_devices = kcalloc(pss->package.count,
+				     sizeof(struct acpi_device *), GFP_KERNEL);
+	if (!tz->domain_devices) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	tz->holders_dir = kobject_create_and_add("measures",
+						 &tz->device->dev.kobj);
+	if (!tz->holders_dir) {
+		ret = -ENOMEM;
+		goto exit_free;
+	}
+
+	tz->num_domain_devices = pss->package.count;
+	for (i = 0; i < pss->package.count; i++) {
+		struct acpi_device *obj;
+		union acpi_object *element = &pss->package.elements[i];
+
+		/* Refuse non-references */
+		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
+			continue;
+
+		/* Create a symlink to domain objects */
+		obj = acpi_get_acpi_dev(element->reference.handle);
+		tz->domain_devices[i] = obj;
+		if (!obj)
+			continue;
+
+		ret = sysfs_create_link(tz->holders_dir, &obj->dev.kobj,
+					kobject_name(&obj->dev.kobj));
+		if (ret) {
+			acpi_dev_put(obj);
+			tz->domain_devices[i] = NULL;
+		}
+	}
+
+	ret = 0;
+	goto end;
+
+exit_free:
+	kfree(tz->domain_devices);
+end:
+	kfree(buffer.pointer);
+	return ret;
+}
+
 static int acpi_thermal_zone_sysfs_add(struct acpi_thermal *tz)
 {
 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
@@ -602,8 +702,19 @@ static int acpi_thermal_zone_sysfs_add(struct acpi_thermal *tz)
 	ret = sysfs_create_link(&tzdev->kobj,
 				   &tz->device->dev.kobj, "device");
 	if (ret)
-		sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
+		goto remove_thermal_zone;
 
+	/* _TZD method is optional. */
+	ret = acpi_thermal_read_domain_devices(tz);
+	if (ret != -ENODEV)
+		goto remove_device;
+
+	return 0;
+
+remove_device:
+	sysfs_remove_link(&tz->device->dev.kobj, "device");
+remove_thermal_zone:
+	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 	return ret;
 }
 
@@ -611,6 +722,7 @@ static void acpi_thermal_zone_sysfs_remove(struct acpi_thermal *tz)
 {
 	struct device *tzdev = thermal_zone_device(tz->thermal_zone);
 
+	acpi_thermal_remove_domain_devices(tz);
 	sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 	sysfs_remove_link(&tzdev->kobj, "device");
 }
-- 
2.22.0

[PATCH v1 2/2] hwmon: (acpi_power_meter) Fix fail to load module on platform without _PMD method

[Huisong Li]

As ACPI spec said, _PMD method is optional. The acpi_power_meter
shouldn't fail to load when the platform hasn't _PMD method.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
---
 drivers/hwmon/acpi_power_meter.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
index 6c8a9c863528..2f1c9d97ad21 100644
--- a/drivers/hwmon/acpi_power_meter.c
+++ b/drivers/hwmon/acpi_power_meter.c
@@ -680,8 +680,9 @@ static int setup_attrs(struct acpi_power_meter_resource *resource)
 {
 	int res = 0;
 
+	/* _PMD method is optional. */
 	res = read_domain_devices(resource);
-	if (res)
+	if (res != -ENODEV)
 		return res;
 
 	if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
-- 
2.22.0

Re: [PATCH v1 2/2] hwmon: (acpi_power_meter) Fix fail to load module on platform without _PMD method

[Rafael J. Wysocki]

On Thu, Nov 7, 2024 at 4:37 AM Huisong Li <lihuisong@huawei.com> wrote:
>
> As ACPI spec said, _PMD method is optional. The acpi_power_meter
> shouldn't fail to load when the platform hasn't _PMD method.
>
> Signed-off-by: Huisong Li <lihuisong@huawei.com>

How exactly is this related to the first patch?

> ---
>  drivers/hwmon/acpi_power_meter.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
> index 6c8a9c863528..2f1c9d97ad21 100644
> --- a/drivers/hwmon/acpi_power_meter.c
> +++ b/drivers/hwmon/acpi_power_meter.c
> @@ -680,8 +680,9 @@ static int setup_attrs(struct acpi_power_meter_resource *resource)
>  {
>         int res = 0;
>
> +       /* _PMD method is optional. */
>         res = read_domain_devices(resource);
> -       if (res)
> +       if (res != -ENODEV)
>                 return res;
>
>         if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
> --
> 2.22.0
>
>

Re: [PATCH v1 2/2] hwmon: (acpi_power_meter) Fix fail to load module on platform without _PMD method

[lihuisong (C)]

在 2024/11/7 18:55, Rafael J. Wysocki 写道:
> On Thu, Nov 7, 2024 at 4:37 AM Huisong Li <lihuisong@huawei.com> wrote:
>> As ACPI spec said, _PMD method is optional. The acpi_power_meter
>> shouldn't fail to load when the platform hasn't _PMD method.
>>
>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
> How exactly is this related to the first patch?
They're not related, they're just similar.
Sorry, I should separate them😂
Should I resend them now?
>
>> ---
>>   drivers/hwmon/acpi_power_meter.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
>> index 6c8a9c863528..2f1c9d97ad21 100644
>> --- a/drivers/hwmon/acpi_power_meter.c
>> +++ b/drivers/hwmon/acpi_power_meter.c
>> @@ -680,8 +680,9 @@ static int setup_attrs(struct acpi_power_meter_resource *resource)
>>   {
>>          int res = 0;
>>
>> +       /* _PMD method is optional. */
>>          res = read_domain_devices(resource);
>> -       if (res)
>> +       if (res != -ENODEV)
>>                  return res;
>>
>>          if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
>> --
>> 2.22.0
>>
>>
> .