Revert "dm: sandbox: Drop the pre-DM host implementation"

Bring this support back so that sandbox can be compiled with CONFIG_BLK. This
allows sandbox to have greater build coverage during the block-device
transition. This can be removed again later.

This reverts commit 33cf727b16.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/block/sandbox.c

@@ -17,6 +17,19 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#ifndef CONFIG_BLK
+static struct host_block_dev host_devices[CONFIG_HOST_MAX_DEVICES];
+
+static struct host_block_dev *find_host_device(int dev)
+{
+	if (dev >= 0 && dev < CONFIG_HOST_MAX_DEVICES)
+		return &host_devices[dev];
+
+	return NULL;
+}
+#endif
+
+#ifdef CONFIG_BLK
 static unsigned long host_block_read(struct udevice *dev,
 				     unsigned long start, lbaint_t blkcnt,
 				     void *buffer)
@@ -24,6 +37,18 @@ static unsigned long host_block_read(struct udevice *dev,
 	struct host_block_dev *host_dev = dev_get_priv(dev);
 	struct blk_desc *block_dev = dev_get_uclass_platdata(dev);
 
+#else
+static unsigned long host_block_read(struct blk_desc *block_dev,
+				     unsigned long start, lbaint_t blkcnt,
+				     void *buffer)
+{
+	int dev = block_dev->devnum;
+	struct host_block_dev *host_dev = find_host_device(dev);
+
+	if (!host_dev)
+		return -1;
+#endif
+
 	if (os_lseek(host_dev->fd, start * block_dev->blksz, OS_SEEK_SET) ==
 			-1) {
 		printf("ERROR: Invalid block %lx\n", start);
@@ -35,12 +60,21 @@ static unsigned long host_block_read(struct udevice *dev,
 	return -1;
 }
 
+#ifdef CONFIG_BLK
 static unsigned long host_block_write(struct udevice *dev,
 				      unsigned long start, lbaint_t blkcnt,
 				      const void *buffer)
 {
 	struct host_block_dev *host_dev = dev_get_priv(dev);
 	struct blk_desc *block_dev = dev_get_uclass_platdata(dev);
+#else
+static unsigned long host_block_write(struct blk_desc *block_dev,
+				      unsigned long start, lbaint_t blkcnt,
+				      const void *buffer)
+{
+	int dev = block_dev->devnum;
+	struct host_block_dev *host_dev = find_host_device(dev);
+#endif
 
 	if (os_lseek(host_dev->fd, start * block_dev->blksz, OS_SEEK_SET) ==
 			-1) {
@@ -53,6 +87,7 @@ static unsigned long host_block_write(struct udevice *dev,
 	return -1;
 }
 
+#ifdef CONFIG_BLK
 int host_dev_bind(int devnum, char *filename)
 {
 	struct host_block_dev *host_dev;
@@ -115,9 +150,51 @@ err:
 	free(str);
 	return ret;
 }
+#else
+int host_dev_bind(int dev, char *filename)
+{
+	struct host_block_dev *host_dev = find_host_device(dev);
+
+	if (!host_dev)
+		return -1;
+	if (host_dev->blk_dev.priv) {
+		os_close(host_dev->fd);
+		host_dev->blk_dev.priv = NULL;
+	}
+	if (host_dev->filename)
+		free(host_dev->filename);
+	if (filename && *filename) {
+		host_dev->filename = strdup(filename);
+	} else {
+		host_dev->filename = NULL;
+		return 0;
+	}
+
+	host_dev->fd = os_open(host_dev->filename, OS_O_RDWR);
+	if (host_dev->fd == -1) {
+		printf("Failed to access host backing file '%s'\n",
+		       host_dev->filename);
+		return 1;
+	}
+
+	struct blk_desc *blk_dev = &host_dev->blk_dev;
+	blk_dev->if_type = IF_TYPE_HOST;
+	blk_dev->priv = host_dev;
+	blk_dev->blksz = 512;
+	blk_dev->lba = os_lseek(host_dev->fd, 0, OS_SEEK_END) / blk_dev->blksz;
+	blk_dev->block_read = host_block_read;
+	blk_dev->block_write = host_block_write;
+	blk_dev->devnum = dev;
+	blk_dev->part_type = PART_TYPE_UNKNOWN;
+	part_init(blk_dev);
+
+	return 0;
+}
+#endif
 
 int host_get_dev_err(int devnum, struct blk_desc **blk_devp)
 {
+#ifdef CONFIG_BLK
 	struct udevice *dev;
 	int ret;
 
@@ -125,6 +202,17 @@ int host_get_dev_err(int devnum, struct blk_desc **blk_devp)
 	if (ret)
 		return ret;
 	*blk_devp = dev_get_uclass_platdata(dev);
+#else
+	struct host_block_dev *host_dev = find_host_device(devnum);
+
+	if (!host_dev)
+		return -ENODEV;
+
+	if (!host_dev->blk_dev.priv)
+		return -ENOENT;
+
+	*blk_devp = &host_dev->blk_dev;
+#endif
 
 	return 0;
 }
@@ -139,6 +227,7 @@ struct blk_desc *host_get_dev(int dev)
 	return blk_dev;
 }
 
+#ifdef CONFIG_BLK
 static const struct blk_ops sandbox_host_blk_ops = {
 	.read	= host_block_read,
 	.write	= host_block_write,
@@ -150,3 +239,4 @@ U_BOOT_DRIVER(sandbox_host_blk) = {
 	.ops		= &sandbox_host_blk_ops,
 	.priv_auto_alloc_size	= sizeof(struct host_block_dev),
 };
+#endif