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;

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;

This patch adds ACPI supports for AHCI platform driver, which uses _CLS method to match the device.

The following is an example of ASL structure in DSDT for a SATA controller, which contains _CLS package to be matched by the ahci_platform driver:

Device (AHC0) // AHCI Controller { Name(_HID, "AMDI0600") Name (_CCA, 1) Name (_CLS, Package (3) { 0x01, // Base Class: Mass Storage 0x06, // Sub-Class: serial ATA 0x01, // Interface: AHCI }) Name (_CRS, ResourceTemplate () { Memory32Fixed (ReadWrite, 0xE0300000, 0x00010000) Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive,,,) { 387 } }) }

Also, since ATA driver should not require PCI support for ATA_ACPI, this patch removes dependency in the driver/ata/Kconfig.

Signed-off-by: Suravee Suthikulpanit Suravee.Suthikulpanit@amd.com --- drivers/ata/Kconfig | 2 +- drivers/ata/ahci_platform.c | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig index cd4cccb..edb00c6 100644 --- a/drivers/ata/Kconfig +++ b/drivers/ata/Kconfig @@ -48,7 +48,7 @@ config ATA_VERBOSE_ERROR

config ATA_ACPI bool "ATA ACPI Support" - depends on ACPI && PCI + depends on ACPI default y help This option adds support for ATA-related ACPI objects. diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c index 06f1d59..4879f9b 100644 --- a/drivers/ata/ahci_platform.c +++ b/drivers/ata/ahci_platform.c @@ -71,6 +71,8 @@ static const struct of_device_id ahci_of_match[] = { }; MODULE_DEVICE_TABLE(of, ahci_of_match);

+static const struct acpi_device_cls ahci_cls = {0x01, 0x06, 0x01}; + static struct platform_driver ahci_driver = { .probe = ahci_probe, .remove = ata_platform_remove_one, @@ -78,6 +80,7 @@ static struct platform_driver ahci_driver = { .name = "ahci", .owner = THIS_MODULE, .of_match_table = ahci_of_match, + .acpi_cls = &ahci_cls, .pm = &ahci_pm_ops, }, };