Thank you for review comment. I am sending out V3 with your suggestions.

Suravee

On 01/22/2015 06:40 AM, Rafael J. Wysocki wrote:

On Monday, January 05, 2015 03:11:14 PM Suravee Suthikulpanit wrote:

...

Device drivers typically use ACPI _HIDs/_CIDs listed in struct device_driver acpi_match_table to match devices. However, for generic drivers, we do not want to list _HID for all supported devices, and some device classes do not have _CID (e.g. SATA, USB). Instead, we can leverage ACPI _CLS, which specifies PCI-defined class code (i.e. base-class, subclass and programming interface).

This patch adds support for matching ACPI devices using the _CLS method.

Signed-off-by: Suravee Suthikulpanit Suravee.Suthikulpanit@amd.com

drivers/acpi/scan.c | 79 +++++++++++++++++++++++++++++++++++++++-- include/acpi/acnames.h | 1 + include/linux/acpi.h | 10 ++++++ include/linux/device.h | 1 + include/linux/mod_devicetable.h | 6 ++++ 5 files changed, 94 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 16914cc..7b25221 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -987,13 +987,86 @@ static bool acpi_of_driver_match_device(struct device *dev, bool acpi_driver_match_device(struct device *dev, const struct device_driver *drv) {

• if (!drv->acpi_match_table)

• return acpi_of_driver_match_device(dev, drv);
  

• bool ret = false;

• return !!acpi_match_device(drv->acpi_match_table, dev);

• if (drv->acpi_match_table)

• ret = !!acpi_match_device(drv->acpi_match_table, dev);
  

• /* Next, try to match with special "PRP0001" _HID */
• if (!ret && drv->of_match_table)

• ret = acpi_of_driver_match_device(dev, drv);
  

• /* Next, try to match with PCI-defined class-code */
• if (!ret && drv->acpi_match_cls)

• ret = acpi_match_device_cls(drv->acpi_match_cls, dev);
  

• return ret; } EXPORT_SYMBOL_GPL(acpi_driver_match_device);

+/**

• • acpi_match_device_cls - Match a struct device against a ACPI _CLS method
• • @dev_cls: A pointer to struct acpi_device_cls object to match against.
• • @dev: The ACPI device structure to match.
• • Check if @dev has a valid ACPI and _CLS handle. If there is a
• • struct acpi_device_cls object for that handle, use that object to match
• • against the given struct acpi_device_cls object.
• • Return true on success or false on failure.
• */

+bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,

• 	  const struct device *dev)
  

+{

• bool ret = false;
• acpi_status status;
• union acpi_object *pkg;
• struct acpi_device_cls cls;
• struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
• struct acpi_buffer format = { sizeof("NNN"), "NNN" };
• struct acpi_buffer state = { 0, NULL };
• struct acpi_device *adev = ACPI_COMPANION(dev);
• acpi_handle handle = ACPI_HANDLE(dev);

That must be equal to adev->handle, so it is not necessary to use ACPI_HANDLE() here.

...

• if (!handle || !adev || !adev->status.present || !dev_cls)

• return ret;
  

return false;

and set 'ret' later. And if you check 'adev', you don't need to check 'handle'. And you can use adev->handle directly below, so the 'handle' variable is not necessary.

...

• status = acpi_evaluate_object(handle, METHOD_NAME__CLS, NULL, &buffer);
• if (ACPI_FAILURE(status))

• return ret;
  

return false;

...

• /**

• * Note:
  

• * ACPIv5.1 defines the package to contain 3 integers for
  

• * Base-Class code, Sub-Class code, and Programming Interface code.
  

• */
  

• pkg = buffer.pointer;
• if (!pkg ||

•    (pkg->type != ACPI_TYPE_PACKAGE) ||
  

•    (pkg->package.count != 3)) {
  

• dev_err(&adev->dev, "Invalid _CLS data\n");
  

dev_dbg() here, please.

...

• goto out;
  

• }
• state.length = sizeof(struct acpi_device_cls);
• state.pointer = &cls;
• status = acpi_extract_package(pkg, &format, &state);
• if (ACPI_FAILURE(status)) {

• ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
  

I'm not sure how useful that message is going to be to be honest.

...

• goto out;
  

• }
• if ((dev_cls->base_class == cls.base_class) &&

•    (dev_cls->sub_class == cls.sub_class) &&
  

•    (dev_cls->prog_interface == cls.prog_interface))
  

• ret = true;
  

ret = dev_cls->base_class == cls.base_class && dev_cls->sub_class == cls.sub_class && dev_cls->prog_interface == cls.prog_interface;

...

+out:

• kfree(buffer.pointer);
• return ret;

+} +EXPORT_SYMBOL_GPL(acpi_match_device_cls);

• static void acpi_free_power_resources_lists(struct acpi_device *device) { int i;

diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h index 7461327..22332a6 100644 --- a/include/acpi/acnames.h +++ b/include/acpi/acnames.h @@ -51,6 +51,7 @@ #define METHOD_NAME__BBN "_BBN" #define METHOD_NAME__CBA "_CBA" #define METHOD_NAME__CID "_CID" +#define METHOD_NAME__CLS "_CLS" #define METHOD_NAME__CRS "_CRS" #define METHOD_NAME__DDN "_DDN" #define METHOD_NAME__HID "_HID" diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 87f365e..2f2b8ce 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -432,6 +432,10 @@ const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,

extern bool acpi_driver_match_device(struct device *dev, const struct device_driver *drv);

+bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,

• 	   const struct device *dev);
  

• int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *); int acpi_device_modalias(struct device *, char *, int); void acpi_walk_dep_device_list(acpi_handle handle);

@@ -527,6 +531,12 @@ static inline const struct acpi_device_id *acpi_match_device( return NULL; }

+static inline bool acpi_match_device_cls(const struct acpi_device_cls *dev_cls,

• 			 const struct device *dev)
  

+{

• return false;

+}

• static inline bool acpi_driver_match_device(struct device *dev, const struct device_driver *drv) {

diff --git a/include/linux/device.h b/include/linux/device.h index fb50673..8e259c5c 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -237,6 +237,7 @@ struct device_driver {

const struct of_device_id *of_match_table; const struct acpi_device_id *acpi_match_table;

• const struct acpi_device_cls *acpi_match_cls;

  int (*probe) (struct device *dev); int (*remove) (struct device *dev);

diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index 745def8..00e94ec 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -186,6 +186,12 @@ struct css_device_id {

#define ACPI_ID_LEN 9

+struct acpi_device_cls {

• kernel_ulong_t base_class;
• kernel_ulong_t sub_class;
• kernel_ulong_t prog_interface;

+};

Move that below the struct acpi_device_id definition.

...

struct acpi_device_id { __u8 id[ACPI_ID_LEN]; kernel_ulong_t driver_data;