soc/amd/common/block/lpc: Add custom SPI DMA boot device
This is a copy of mmap_boot.c and mem_rdev_ro_ops. I split it up so it
was easier to review.
The next patches will add support for the SPI DMA controller. This will
provide a minor speed up vs using mmap reads. It will also provide the
facilities to perform asynchronous SPI loading.
BUG=b:179699789
TEST=Boot guybrush to OS
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: Id26e2a69601d0f31e256d0010008904a447c8e21
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55854
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/soc/amd/common/block/lpc/spi_dma.c b/src/soc/amd/common/block/lpc/spi_dma.c
new file mode 100644
index 0000000..470bfb1
--- /dev/null
+++ b/src/soc/amd/common/block/lpc/spi_dma.c
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <boot_device.h>
+#include <commonlib/helpers.h>
+#include <commonlib/region.h>
+#include <spi_flash.h>
+#include <string.h>
+#include <types.h>
+
+/* The ROM is memory mapped just below 4GiB. Form a pointer for the base. */
+#define rom_base ((void *)(uintptr_t)(0x100000000ULL - CONFIG_ROM_SIZE))
+
+static void *spi_dma_mmap(const struct region_device *rd, size_t offset, size_t size __unused)
+{
+ const struct mem_region_device *mdev;
+
+ mdev = container_of(rd, __typeof__(*mdev), rdev);
+
+ return &mdev->base[offset];
+}
+
+static int spi_dma_munmap(const struct region_device *rd __unused, void *mapping __unused)
+{
+ return 0;
+}
+
+static ssize_t spi_dma_readat_mmap(const struct region_device *rd, void *b, size_t offset,
+ size_t size)
+{
+ const struct mem_region_device *mdev;
+
+ mdev = container_of(rd, __typeof__(*mdev), rdev);
+
+ memcpy(b, &mdev->base[offset], size);
+
+ return size;
+}
+
+const struct region_device_ops spi_dma_rdev_ro_ops = {
+ .mmap = spi_dma_mmap,
+ .munmap = spi_dma_munmap,
+ .readat = spi_dma_readat_mmap,
+};
+
+static const struct mem_region_device boot_dev = {
+ .base = rom_base,
+ .rdev = REGION_DEV_INIT(&spi_dma_rdev_ro_ops, 0, CONFIG_ROM_SIZE),
+};
+
+const struct region_device *boot_device_ro(void)
+{
+ return &boot_dev.rdev;
+}
+
+uint32_t spi_flash_get_mmap_windows(struct flash_mmap_window *table)
+{
+ table->flash_base = 0;
+ table->host_base = (uint32_t)(uintptr_t)rom_base;
+ table->size = CONFIG_ROM_SIZE;
+
+ return 1;
+}