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SubjectRe: [PATCH 1/2] ACPI / scan: Add support for ACPI _CLS device matching
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 <Suravee.Suthikulpanit@amd.com>
> ---
> 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 <hanjun.guo@linaro.org>

Thanks
Hanjun


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