efi: Add uclass for devices provided by UEFI firmware

UCLASS_EFI_LOADER is used for devices created by applications and
drivers loaded by U-Boots UEFI implementation.

This patch provides a new uclass (UCLASS_EFI_MEDIA) to be used for devices
that provided by a UEFI firmware calling U-Boot as an EFI application.

If the two uclasses can be unified, is left to future redesign.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 56a4eec..755fdcc 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -61,6 +61,29 @@
 	help
 	  This option enables the disk-block cache in TPL
 
+config EFI_MEDIA
+	bool "Support EFI media drivers"
+	default y if EFI || SANDBOX
+	help
+	  Enable this to support media devices on top of UEFI. This enables
+	  just the uclass so you also need a specific driver to make this do
+	  anything.
+
+	  For sandbox there is a test driver.
+
+if EFI_MEDIA
+
+config EFI_MEDIA_SANDBOX
+	bool "Sandbox EFI media driver"
+	depends on SANDBOX
+	default y
+	help
+	  Enables a simple sandbox media driver, used for testing just the
+	  EFI_MEDIA uclass. It does not do anything useful, since sandbox does
+	  not actually support running on top of UEFI.
+
+endif  # EFI_MEDIA
+
 config IDE
 	bool "Support IDE controllers"
 	select HAVE_BLOCK_DEVICE
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 94ab5c6..3778633 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -14,3 +14,6 @@
 endif
 obj-$(CONFIG_SANDBOX) += sandbox.o
 obj-$(CONFIG_$(SPL_TPL_)BLOCK_CACHE) += blkcache.o
+
+obj-$(CONFIG_EFI_MEDIA) += efi-media-uclass.o
+obj-$(CONFIG_EFI_MEDIA_SANDBOX) += sb_efi_media.o
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index a7470ae..4ae8af6 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -28,6 +28,7 @@
 	[IF_TYPE_SATA]		= "sata",
 	[IF_TYPE_HOST]		= "host",
 	[IF_TYPE_NVME]		= "nvme",
+	[IF_TYPE_EFI_MEDIA]	= "efi",
 	[IF_TYPE_EFI_LOADER]	= "efiloader",
 	[IF_TYPE_VIRTIO]	= "virtio",
 	[IF_TYPE_PVBLOCK]	= "pvblock",
@@ -44,6 +45,7 @@
 	[IF_TYPE_SATA]		= UCLASS_AHCI,
 	[IF_TYPE_HOST]		= UCLASS_ROOT,
 	[IF_TYPE_NVME]		= UCLASS_NVME,
+	[IF_TYPE_EFI_MEDIA]	= UCLASS_EFI_MEDIA,
 	[IF_TYPE_EFI_LOADER]	= UCLASS_EFI_LOADER,
 	[IF_TYPE_VIRTIO]	= UCLASS_VIRTIO,
 	[IF_TYPE_PVBLOCK]	= UCLASS_PVBLOCK,
diff --git a/drivers/block/efi-media-uclass.c b/drivers/block/efi-media-uclass.c
new file mode 100644
index 0000000..e012f6f
--- /dev/null
+++ b/drivers/block/efi-media-uclass.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Uclass for EFI media devices
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+
+UCLASS_DRIVER(efi_media) = {
+	.id		= UCLASS_EFI_MEDIA,
+	.name		= "efi_media",
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+};
diff --git a/drivers/block/sb_efi_media.c b/drivers/block/sb_efi_media.c
new file mode 100644
index 0000000..52af155
--- /dev/null
+++ b/drivers/block/sb_efi_media.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * EFI_MEDIA driver for sandbox
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+
+static const struct udevice_id sandbox_efi_media_ids[] = {
+	{ .compatible = "sandbox,efi-media" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_efi_media) = {
+	.name		= "sandbox_efi_media",
+	.id		= UCLASS_EFI_MEDIA,
+	.of_match	= sandbox_efi_media_ids,
+};