Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752573AbaLSO5C (ORCPT ); Fri, 19 Dec 2014 09:57:02 -0500 Received: from mail-pa0-f48.google.com ([209.85.220.48]:47970 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165AbaLSO5A (ORCPT ); Fri, 19 Dec 2014 09:57:00 -0500 Message-ID: <54943CB5.2030206@linaro.org> Date: Fri, 19 Dec 2014 22:56:53 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Suravee Suthikulpanit , rjw@rjwysocki.net, lenb@kernel.org, hdegoede@redhat.com, tj@kernel.org, arnd@arndb.de, mjg59@srcf.ucam.org CC: leo.duran@amd.com, graeme.gregory@linaro.org, linux-ide@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-acpi@lists.linaro.org Subject: Re: [RFC PATCH 1/2] ACPI / scan: Add support for ACPI _CLS device matching References: <1418858195-22857-1-git-send-email-suravee.suthikulpanit@amd.com> <1418858195-22857-2-git-send-email-suravee.suthikulpanit@amd.com> In-Reply-To: <1418858195-22857-2-git-send-email-suravee.suthikulpanit@amd.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Suravee, On 2014年12月18日 07:16, Suravee Suthikulpanit wrote: > From: Suravee Suthikulpanit > > 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 > --- > drivers/acpi/scan.c | 73 +++++++++++++++++++++++++++++++++++++++++ > include/acpi/acnames.h | 1 + > include/linux/acpi.h | 12 ++++++- > include/linux/device.h | 1 + > include/linux/mod_devicetable.h | 6 ++++ > 5 files changed, 92 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index d670158..6406648 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -864,6 +864,79 @@ 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; > + struct acpi_device *adev; > + 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 }; > + acpi_handle handle = ACPI_HANDLE(dev); ... > + acpi_handle cls_handle; > + > + if (!handle || acpi_bus_get_device(handle, &adev)) if handle is not NULL, adev will not NULL too :) because you get the handle from adev, ACPI_HANDLE() is defined as: acpi_device_handle(ACPI_COMPANION(dev)), and adev = ACPI_COMPANION(dev); you may use adev = ACPI_COMPANION(dev) to simplify the code. > + return ret; > + > + if (!adev->status.present || !dev_cls) > + return ret; > + > + status = acpi_get_handle(adev->handle, METHOD_NAME__CLS, &cls_handle); do we need this function called here? _CLS is the method under ACPI device object in DSDT/SSDT, and you will get adev->handle == cls_handle if I'm not wrong :) > + if (ACPI_FAILURE(status)) > + return ret; > + > + status = acpi_evaluate_object(cls_handle, "_CLS", NULL, &buffer); > + if (ACPI_FAILURE(status)) { > + ACPI_EXCEPTION((AE_INFO, status, "Failed to Evaluat _CLS")); > + return ret; > + } I think you can evaluate _CLS directly with handle here. Thanks Hanjun > + > + /** > + * 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..8680afa 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 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; > > 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 44eeef0..f2ef3c6 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; > +}; > + > struct acpi_device_id { > __u8 id[ACPI_ID_LEN]; > kernel_ulong_t driver_data; > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/