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@xxxxxxxxxxxxxxx> Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> --- drivers/acpi/scan.c | 32 ++++++++++++++++++++++++++++++-- include/linux/acpi.h | 14 ++++++++++++++ include/linux/mod_devicetable.h | 2 ++ scripts/mod/devicetable-offsets.c | 2 ++ scripts/mod/file2alias.c | 32 ++++++++++++++++++++++++++++++-- 5 files changed, 78 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 79a48bb..f0662aa 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1017,6 +1017,29 @@ static bool acpi_of_match_device(struct acpi_device *adev, return false; } +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, @@ -1034,9 +1057,12 @@ static const struct acpi_device_id *__acpi_match_device( list_for_each_entry(hwid, &device->pnp.ids, list) { /* First, check the ACPI/PNP IDs provided by the caller. */ - for (id = ids; id->id[0]; id++) - if (!strcmp((char *) id->id, hwid->id)) + for (id = ids; id->id[0] || id->cls; id++) { + if (id->id[0] && !strcmp((char *) id->id, hwid->id)) return id; + else if (id->cls && __acpi_match_device_cls(id, hwid)) + return id; + } /* * Next, check the special "PRP0001" ID and try to match the @@ -2057,6 +2083,8 @@ 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/linux/acpi.h b/include/linux/acpi.h index e4da5e3..b10c4a6 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -58,6 +58,19 @@ static inline acpi_handle acpi_device_handle(struct acpi_device *adev) acpi_fwnode_handle(adev) : NULL) #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 bool has_acpi_companion(struct device *dev) { return is_acpi_node(dev->fwnode); @@ -465,6 +478,7 @@ 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 3bfd567..242037b 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 fce36d0..0ced0ca 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 78691d5..ea238e2f 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); -- 2.1.0 -- 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