From 26095a01d359827eeccec5459c28ddd976183179 Mon Sep 17 00:00:00 2001 From: "Suthikulpanit, Suravee" Date: Tue, 7 Jul 2015 01:55:20 +0200 Subject: ACPI / scan: Add support for ACPI _CLS device matching 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::::..::: 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 Reviewed-by: Hanjun Guo Signed-off-by: Suravee Suthikulpanit Signed-off-by: Rafael J. Wysocki --- scripts/mod/devicetable-offsets.c | 2 ++ scripts/mod/file2alias.c | 32 ++++++++++++++++++++++++++++++-- 2 files changed, 32 insertions(+), 2 deletions(-) (limited to 'scripts') diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c index eff7de1fc82e..e70fcd12eeeb 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 84c86f3cd6cd..5f2088209132 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -523,12 +523,40 @@ 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); -- cgit v1.2.3