On 2014年12月20日 04:13, 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 <[email protected]>
---
drivers/acpi/scan.c | 63 +++++++++++++++++++++++++++++++++++++++++
include/acpi/acnames.h | 1 +
include/linux/acpi.h | 12 +++++++-
include/linux/device.h | 1 +
include/linux/mod_devicetable.h | 6 ++++
5 files changed, 82 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index d670158..6bf6f90 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -864,6 +864,69 @@ int acpi_match_device_ids(struct acpi_device *device,
}
EXPORT_SYMBOL(acpi_match_device_ids);
+/**
+ * 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 0 on success or error code on failure.
+ */
+int acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+ const struct device *dev)
+{
+ int ret = -EINVAL;
+ 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);
+
+ if (!handle || !adev || !adev->status.present || !dev_cls)
+ return ret;
+
+ status = acpi_evaluate_object(handle, METHOD_NAME__CLS, NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return ret;
+
+ /**
+ * 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");
+ 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"));
+ 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 = 0;
+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 5a92d49..d377623 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -428,10 +428,14 @@ extern int acpi_nvs_for_each_region(int (*func)(__u64,
__u64, void *),
const struct acpi_device_id *acpi_match_device(const struct acpi_device_id
*ids,
const struct device *dev);
+int acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+ const struct device *dev);
+
static inline bool acpi_driver_match_device(struct device *dev,
const struct device_driver *drv)
{
- return !!acpi_match_device(drv->acpi_match_table, dev);
+ return (!!acpi_match_device(drv->acpi_match_table, dev) ||
+ !acpi_match_device_cls(drv->acpi_cls, dev));
}
int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
@@ -511,6 +515,12 @@ static inline const struct acpi_device_id
*acpi_match_device(
return NULL;
}
+static inline int acpi_match_device_cls(const struct acpi_device_cls *dev_cls,
+ const struct device *dev)
+{
+ return -EINVAL;
+}
+
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 ce1f2160..a469adc 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_cls;
How about const struct acpi_device_cls *acpi_match_cls; ?
Other than that,
Reviewed-by: Hanjun Guo <[email protected]>
Thanks
Hanjun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
