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. Also, certain classes of devices 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.
To support loadable module, current design uses _HID or _CID to match device's modalias. With the new way of matching with _CLS this would requires modification to the current ACPI modalias key to include _CLS. This patch appends PCI-defined class-code to the existing ACPI modalias as following.
acpi:<HID>:<CID1>:<CID2>:..:<CIDn>:<bbsspp>: E.g: # cat /sys/devices/platform/AMDI0600:00/modalias acpi:AMDI0600:010601:
where bb is th base-class code, ss is te sub-class code, and pp is the programming interface code
Since there would not be _HID/_CID in the ACPI matching table of the driver, this patch adds a field to acpi_device_id to specify the matching _CLS.
static const struct acpi_device_id ahci_acpi_match[] = { { ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) }, {}, };
In this case, the corresponded entry in modules.alias file would be:
alias acpi*:010601:* ahci_platform
Acked-by: Mika Westerberg mika.westerberg@linux.intel.com Reviewed-by: Hanjun Guo hanjun.guo@linaro.org Signed-off-by: Suravee Suthikulpanit Suravee.Suthikulpanit@amd.com --- drivers/acpi/scan.c | 36 ++++++++++++++++++++++++++++++++---- include/acpi/acnames.h | 1 + include/acpi/actypes.h | 4 +++- include/linux/acpi.h | 14 ++++++++++++++ include/linux/mod_devicetable.h | 2 ++ scripts/mod/devicetable-offsets.c | 2 ++ scripts/mod/file2alias.c | 32 ++++++++++++++++++++++++++++++-- 7 files changed, 84 insertions(+), 7 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index c03cadb..d8551cd 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -900,6 +900,29 @@ static void acpi_device_remove_files(struct acpi_device *dev) ACPI Bus operations -------------------------------------------------------------------------- */
+static bool __acpi_match_device_cls(const struct acpi_device_id *id, + struct acpi_hardware_id *hwid) +{ + int i, msk, byte_shift; + char buf[3]; + + if (!id->cls) + return false; + + /* Apply class-code bitmask, before checking each class-code byte */ + for (i = 1; i <= 3; i++) { + byte_shift = 8 * (3 - i); + msk = (id->cls_msk >> byte_shift) & 0xFF; + if (!msk) + continue; + + sprintf(buf, "%02x", (id->cls >> byte_shift) & msk); + if (strncmp(buf, &hwid->id[(i - 1) * 2], 2)) + return false; + } + return true; +} + static const struct acpi_device_id *__acpi_match_device( struct acpi_device *device, const struct acpi_device_id *ids) { @@ -913,11 +936,14 @@ static const struct acpi_device_id *__acpi_match_device( if (!device->status.present) return NULL;
- for (id = ids; id->id[0]; id++) - list_for_each_entry(hwid, &device->pnp.ids, list) - if (!strcmp((char *) id->id, hwid->id)) + for (id = ids; id->id[0] || id->cls; id++) { + list_for_each_entry(hwid, &device->pnp.ids, list) { + if (id->id[0] && !strcmp((char *) id->id, hwid->id)) return id; - + else if (__acpi_match_device_cls(id, hwid)) + return id; + } + } return NULL; }
@@ -2032,6 +2058,8 @@ static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp, if (info->valid & ACPI_VALID_UID) pnp->unique_id = kstrdup(info->unique_id.string, GFP_KERNEL); + if (info->valid & ACPI_VALID_CLS) + acpi_add_id(pnp, info->cls.string);
kfree(info);
diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h index 273de70..b52c0dc 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/acpi/actypes.h b/include/acpi/actypes.h index b034f10..ab3dac8 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -1148,7 +1148,7 @@ struct acpi_device_info { u32 name; /* ACPI object Name */ acpi_object_type type; /* ACPI object Type */ u8 param_count; /* If a method, required parameter count */ - u8 valid; /* Indicates which optional fields are valid */ + u16 valid; /* Indicates which optional fields are valid */ u8 flags; /* Miscellaneous info */ u8 highest_dstates[4]; /* _sx_d values: 0xFF indicates not valid */ u8 lowest_dstates[5]; /* _sx_w values: 0xFF indicates not valid */ @@ -1157,6 +1157,7 @@ struct acpi_device_info { struct acpi_pnp_device_id hardware_id; /* _HID value */ struct acpi_pnp_device_id unique_id; /* _UID value */ struct acpi_pnp_device_id subsystem_id; /* _SUB value */ + struct acpi_pnp_device_id cls; /* _CLS value */ struct acpi_pnp_device_id_list compatible_id_list; /* _CID list <must be last> */ };
@@ -1174,6 +1175,7 @@ struct acpi_device_info { #define ACPI_VALID_CID 0x20 #define ACPI_VALID_SXDS 0x40 #define ACPI_VALID_SXWS 0x80 +#define ACPI_VALID_CLS 0x100
/* Flags for _STA return value (current_status above) */
diff --git a/include/linux/acpi.h b/include/linux/acpi.h index de4e86f..3d1e5dd 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -57,6 +57,19 @@ static inline acpi_handle acpi_device_handle(struct acpi_device *adev) #define ACPI_COMPANION_SET(dev, adev) ACPI_COMPANION(dev) = (adev) #define ACPI_HANDLE(dev) acpi_device_handle(ACPI_COMPANION(dev))
+/** + * ACPI_DEVICE_CLASS - macro used to describe an ACPI device with + * the PCI-defined class-code information + * + * @_cls : the class, subclass, prog-if triple for this device + * @_msk : the class mask for this device + * + * This macro is used to create a struct acpi_device_id that matches a + * specific PCI class. The .id and .driver_data fields will be left + * initialized with the default value. + */ +#define ACPI_DEVICE_CLASS(_cls, _msk) .cls = (_cls), .cls_msk = (_msk), + static inline void acpi_preset_companion(struct device *dev, struct acpi_device *parent, u64 addr) { @@ -459,6 +472,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *); #define ACPI_COMPANION(dev) (NULL) #define ACPI_COMPANION_SET(dev, adev) do { } while (0) #define ACPI_HANDLE(dev) (NULL) +#define ACPI_DEVICE_CLASS(_cls, _msk) .cls = (0), .cls_msk = (0),
struct fwnode_handle;
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index e530533..2ed31b8 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -189,6 +189,8 @@ struct css_device_id { struct acpi_device_id { __u8 id[ACPI_ID_LEN]; kernel_ulong_t driver_data; + __u32 cls; + __u32 cls_msk; };
#define PNP_ID_LEN 8 diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c index f282516..8987160 100644 --- a/scripts/mod/devicetable-offsets.c +++ b/scripts/mod/devicetable-offsets.c @@ -63,6 +63,8 @@ int main(void)
DEVID(acpi_device_id); DEVID_FIELD(acpi_device_id, id); + DEVID_FIELD(acpi_device_id, cls); + DEVID_FIELD(acpi_device_id, cls_msk);
DEVID(pnp_device_id); DEVID_FIELD(pnp_device_id, id); diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index e614ef6..704d597 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -511,12 +511,40 @@ static int do_serio_entry(const char *filename, } ADD_TO_DEVTABLE("serio", serio_device_id, do_serio_entry);
-/* looks like: "acpi:ACPI0003 or acpi:PNP0C0B" or "acpi:LNXVIDEO" */ +/* looks like: "acpi:ACPI0003" or "acpi:PNP0C0B" or "acpi:LNXVIDEO" or + * "acpi:bbsspp" (bb=base-class, ss=sub-class, pp=prog-if) + * + * NOTE: Each driver should use one of the following : _HID, _CIDs + * or _CLS. Also, bb, ss, and pp can be substituted with ?? + * as don't care byte. + */ static int do_acpi_entry(const char *filename, void *symval, char *alias) { DEF_FIELD_ADDR(symval, acpi_device_id, id); - sprintf(alias, "acpi*:%s:*", *id); + DEF_FIELD_ADDR(symval, acpi_device_id, cls); + DEF_FIELD_ADDR(symval, acpi_device_id, cls_msk); + + if (id && strlen((const char *)*id)) + sprintf(alias, "acpi*:%s:*", *id); + else if (cls) { + int i, byte_shift, cnt = 0; + unsigned int msk; + + sprintf(&alias[cnt], "acpi*:"); + cnt = 6; + for (i = 1; i <= 3; i++) { + byte_shift = 8 * (3-i); + msk = (*cls_msk >> byte_shift) & 0xFF; + if (msk) + sprintf(&alias[cnt], "%02x", + (*cls >> byte_shift) & 0xFF); + else + sprintf(&alias[cnt], "??"); + cnt += 2; + } + sprintf(&alias[cnt], ":*"); + } return 1; } ADD_TO_DEVTABLE("acpi", acpi_device_id, do_acpi_entry);