firmware: dmi: Add access to the SKU ID string

This is used in some systems from user space for determining the identity
of the device.

Expose this as a file so that that user-space tools don't need to read
from /sys/firmware/dmi/tables/DMI
Signed-off-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

drivers/firmware/dmi-id.c

@@ -47,6 +47,7 @@ DEFINE_DMI_ATTR_WITH_SHOW(product_name,		0444, DMI_PRODUCT_NAME);
 DEFINE_DMI_ATTR_WITH_SHOW(product_version,	0444, DMI_PRODUCT_VERSION);
 DEFINE_DMI_ATTR_WITH_SHOW(product_serial,	0400, DMI_PRODUCT_SERIAL);
 DEFINE_DMI_ATTR_WITH_SHOW(product_uuid,		0400, DMI_PRODUCT_UUID);
+DEFINE_DMI_ATTR_WITH_SHOW(product_sku,		0444, DMI_PRODUCT_SKU);
 DEFINE_DMI_ATTR_WITH_SHOW(product_family,	0444, DMI_PRODUCT_FAMILY);
 DEFINE_DMI_ATTR_WITH_SHOW(board_vendor,		0444, DMI_BOARD_VENDOR);
 DEFINE_DMI_ATTR_WITH_SHOW(board_name,		0444, DMI_BOARD_NAME);
@@ -193,6 +194,7 @@ static void __init dmi_id_init_attr_table(void)
 	ADD_DMI_ATTR(product_serial,    DMI_PRODUCT_SERIAL);
 	ADD_DMI_ATTR(product_uuid,      DMI_PRODUCT_UUID);
 	ADD_DMI_ATTR(product_family,    DMI_PRODUCT_FAMILY);
+	ADD_DMI_ATTR(product_sku,       DMI_PRODUCT_SKU);
 	ADD_DMI_ATTR(board_vendor,      DMI_BOARD_VENDOR);
 	ADD_DMI_ATTR(board_name,        DMI_BOARD_NAME);
 	ADD_DMI_ATTR(board_version,     DMI_BOARD_VERSION);

drivers/firmware/dmi_scan.c

@@ -447,6 +447,7 @@ static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
 		dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
+		dmi_save_ident(dm, DMI_PRODUCT_SKU, 25);
 		dmi_save_ident(dm, DMI_PRODUCT_FAMILY, 26);
 		break;
 	case 2:		/* Base Board Information */

include/linux/mod_devicetable.h

@@ -490,6 +490,7 @@ enum dmi_field {
 	DMI_PRODUCT_VERSION,
 	DMI_PRODUCT_SERIAL,
 	DMI_PRODUCT_UUID,
+	DMI_PRODUCT_SKU,
 	DMI_PRODUCT_FAMILY,
 	DMI_BOARD_VENDOR,
 	DMI_BOARD_NAME,