bootstd: mmc: Add a bootdev driver
Add a bootdev driver for MMC. It mostly just calls the bootdev helper
function.
Add a function to obtain the block device for an MMC controller.
Fix up the comment for mmc_get_blk_desc() while we are here.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mmc/mmc_bootdev.c b/drivers/mmc/mmc_bootdev.c
new file mode 100644
index 0000000..b4f41fb
--- /dev/null
+++ b/drivers/mmc/mmc_bootdev.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Bootdevice for MMC
+ *
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <bootdev.h>
+#include <dm.h>
+#include <mmc.h>
+
+static int mmc_get_bootflow(struct udevice *dev, struct bootflow_iter *iter,
+ struct bootflow *bflow)
+{
+ struct udevice *mmc_dev = dev_get_parent(dev);
+ struct udevice *blk;
+ int ret;
+
+ ret = mmc_get_blk(mmc_dev, &blk);
+ /*
+ * If there is no media, indicate that no more partitions should be
+ * checked
+ */
+ if (ret == -EOPNOTSUPP)
+ ret = -ESHUTDOWN;
+ if (ret)
+ return log_msg_ret("blk", ret);
+ assert(blk);
+ ret = bootdev_find_in_blk(dev, blk, iter, bflow);
+ if (ret)
+ return log_msg_ret("find", ret);
+
+ return 0;
+}
+
+static int mmc_bootdev_bind(struct udevice *dev)
+{
+ struct bootdev_uc_plat *ucp = dev_get_uclass_plat(dev);
+
+ ucp->prio = BOOTDEVP_0_INTERNAL_FAST;
+
+ return 0;
+}
+
+struct bootdev_ops mmc_bootdev_ops = {
+ .get_bootflow = mmc_get_bootflow,
+};
+
+static const struct udevice_id mmc_bootdev_ids[] = {
+ { .compatible = "u-boot,bootdev-mmc" },
+ { }
+};
+
+U_BOOT_DRIVER(mmc_bootdev) = {
+ .name = "mmc_bootdev",
+ .id = UCLASS_BOOTDEV,
+ .ops = &mmc_bootdev_ops,
+ .bind = mmc_bootdev_bind,
+ .of_match = mmc_bootdev_ids,
+};