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@xxxxxxx> > --- > 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; > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html