4 files changed, 207 insertions, 6 deletions

diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 25194eeec1..d1b40c6140 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -17,4 +17,5 @@ endif
 
 ifdef CONFIG_SCSI
 obj-$(CONFIG_SANDBOX) += sandbox_scsi.o
+obj-$(CONFIG_SANDBOX) += scsi_emul.o
 endif
diff --git a/drivers/scsi/sandbox_scsi.c b/drivers/scsi/sandbox_scsi.c
index 39b969a4b2..a7ac33cb1c 100644
--- a/drivers/scsi/sandbox_scsi.c
+++ b/drivers/scsi/sandbox_scsi.c
@@ -7,19 +7,145 @@
  * that CONFIG_SCSI can be enabled for sandbox.
  */
 
+#define LOG_CATEGORY UCLASS_SCSI
+
 #include <common.h>
+#include <dm.h>
+#include <os.h>
+#include <malloc.h>
 #include <scsi.h>
+#include <scsi_emul.h>
+
+enum {
+	SANDBOX_SCSI_BLOCK_LEN		= 512,
+	SANDBOX_SCSI_BUF_SIZE		= 512,
+};
+
+/**
+ * struct sandbox_scsi_priv
+ *
+ * @eminfo: emulator state
+ * @pathanme: Path to the backing file, e.g. 'scsi.img'
+ * @fd: File descriptor of backing file
+ */
+struct sandbox_scsi_priv {
+	struct scsi_emul_info eminfo;
+	const char *pathname;
+	int fd;
+};
 
-int scsi_bus_reset(struct udevice *dev)
+static int sandbox_scsi_exec(struct udevice *dev, struct scsi_cmd *req)
 {
+	struct sandbox_scsi_priv *priv = dev_get_priv(dev);
+	struct scsi_emul_info *info = &priv->eminfo;
+	int ret;
+
+	if (req->lun || req->target)
+		return -EIO;
+	ret = sb_scsi_emul_command(info, req, req->cmdlen);
+	if (ret < 0) {
+		log_debug("SCSI command 0x%02x ret errno %d\n", req->cmd[0],
+			  ret);
+		return ret;
+	} else if (ret == SCSI_EMUL_DO_READ && priv->fd != -1) {
+		long bytes_read;
+
+		log_debug("read %x %x\n", info->seek_block, info->read_len);
+		os_lseek(priv->fd, info->seek_block * info->block_size,
+			 OS_SEEK_SET);
+		bytes_read = os_read(priv->fd, req->pdata, info->buff_used);
+		if (bytes_read < 0)
+			return bytes_read;
+		if (bytes_read != info->buff_used)
+			return -EIO;
+	} else if (!ret) {
+		req->pdata = info->buff;
+		info->phase = SCSIPH_STATUS;
+		log_debug("sending buf\n");
+	} else {
+		log_debug("error\n");
+		return -EIO;
+	}
+
 	return 0;
 }
 
-void scsi_init(void)
+static int sandbox_scsi_bus_reset(struct udevice *dev)
 {
+	/* Not implemented */
+
+	return 0;
 }
 
-int scsi_exec(struct udevice *dev, struct scsi_cmd *pccb)
+static int sandbox_scsi_of_to_plat(struct udevice *dev)
 {
+	struct sandbox_scsi_priv *priv = dev_get_priv(dev);
+
+	priv->pathname = dev_read_string(dev, "sandbox,filepath");
+
 	return 0;
 }
+
+static int sandbox_scsi_probe(struct udevice *dev)
+{
+	struct scsi_plat *scsi_plat = dev_get_uclass_plat(dev);
+	struct sandbox_scsi_priv *priv = dev_get_priv(dev);
+	struct scsi_emul_info *info = &priv->eminfo;
+	int ret;
+
+	scsi_plat->max_id = 2;
+	scsi_plat->max_lun = 3;
+	scsi_plat->max_bytes_per_req = 1 << 20;
+
+	info->vendor = "SANDBOX";
+	info->product = "FAKE DISK";
+	info->buff = malloc(SANDBOX_SCSI_BUF_SIZE);
+	if (!info->buff)
+		return log_ret(-ENOMEM);
+	info->block_size = SANDBOX_SCSI_BLOCK_LEN;
+
+	if (priv->pathname) {
+		priv->fd = os_open(priv->pathname, OS_O_RDONLY);
+		if (priv->fd != -1) {
+			ret = os_get_filesize(priv->pathname, &info->file_size);
+			if (ret)
+				return log_msg_ret("sz", ret);
+		}
+	} else {
+		priv->fd = -1;
+	}
+	log_debug("filename: %s, fd %d\n", priv->pathname, priv->fd);
+
+	return 0;
+}
+
+static int sandbox_scsi_remove(struct udevice *dev)
+{
+	struct sandbox_scsi_priv *priv = dev_get_priv(dev);
+	struct scsi_emul_info *info = &priv->eminfo;
+
+	free(info->buff);
+
+	return 0;
+}
+
+struct scsi_ops sandbox_scsi_ops = {
+	.exec		= sandbox_scsi_exec,
+	.bus_reset	= sandbox_scsi_bus_reset,
+};
+
+static const struct udevice_id sanbox_scsi_ids[] = {
+	{ .compatible = "sandbox,scsi" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_scsi) = {
+	.name		= "sandbox_scsi",
+	.id		= UCLASS_SCSI,
+	.ops		= &sandbox_scsi_ops,
+	.of_match	= sanbox_scsi_ids,
+	.of_to_plat	= sandbox_scsi_of_to_plat,
+	.probe		= sandbox_scsi_probe,
+	.remove		= sandbox_scsi_remove,
+	.priv_auto	= sizeof(struct sandbox_scsi_priv),
+};
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 99be5aef87..3e769b0843 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -456,7 +456,7 @@ static void scsi_init_dev_desc(struct blk_desc *dev_desc, int devnum)
 {
 	dev_desc->lba = 0;
 	dev_desc->blksz = 0;
-	dev_desc->if_type = UCLASS_SCSI;
+	dev_desc->uclass_id = UCLASS_SCSI;
 	dev_desc->devnum = devnum;
 	dev_desc->part_type = PART_TYPE_UNKNOWN;
 
@@ -706,8 +706,8 @@ U_BOOT_DRIVER(scsi_blk) = {
 };
 #else
 U_BOOT_LEGACY_BLK(scsi) = {
-	.if_typename	= "scsi",
-	.if_type	= UCLASS_SCSI,
+	.uclass_idname	= "scsi",
+	.uclass_id	= UCLASS_SCSI,
 	.max_devs	= SCSI_MAX_DEVICE,
 	.desc		= scsi_dev_desc,
 };
diff --git a/drivers/scsi/scsi_emul.c b/drivers/scsi/scsi_emul.c
new file mode 100644
index 0000000000..5ba364bdac
--- /dev/null
+++ b/drivers/scsi/scsi_emul.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Emulation of enough SCSI commands to find and read from a unit
+ *
+ * Copyright 2022 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * implementation of SCSI functions required so that CONFIG_SCSI can be enabled
+ * for sandbox.
+ */
+
+#define LOG_CATEGORY UCLASS_SCSI
+
+#include <common.h>
+#include <dm.h>
+#include <log.h>
+#include <scsi.h>
+#include <scsi_emul.h>
+
+int sb_scsi_emul_command(struct scsi_emul_info *info,
+			 const struct scsi_cmd *req, int len)
+{
+	int ret = 0;
+
+	info->buff_used = 0;
+	log_debug("emul %x\n", *req->cmd);
+	switch (*req->cmd) {
+	case SCSI_INQUIRY: {
+		struct scsi_inquiry_resp *resp = (void *)info->buff;
+
+		info->alloc_len = req->cmd[4];
+		memset(resp, '\0', sizeof(*resp));
+		resp->data_format = 1;
+		resp->additional_len = 0x1f;
+		strncpy(resp->vendor, info->vendor, sizeof(resp->vendor));
+		strncpy(resp->product, info->product, sizeof(resp->product));
+		strncpy(resp->revision, "1.0", sizeof(resp->revision));
+		info->buff_used = sizeof(*resp);
+		break;
+	}
+	case SCSI_TST_U_RDY:
+		break;
+	case SCSI_RD_CAPAC: {
+		struct scsi_read_capacity_resp *resp = (void *)info->buff;
+		uint blocks;
+
+		if (info->file_size)
+			blocks = info->file_size / info->block_size - 1;
+		else
+			blocks = 0;
+		resp->last_block_addr = cpu_to_be32(blocks);
+		resp->block_len = cpu_to_be32(info->block_size);
+		info->buff_used = sizeof(*resp);
+		break;
+	}
+	case SCSI_READ10: {
+		const struct scsi_read10_req *read_req = (void *)req;
+
+		info->seek_block = be32_to_cpu(read_req->lba);
+		info->read_len = be16_to_cpu(read_req->xfer_len);
+		info->buff_used = info->read_len * info->block_size;
+		ret = SCSI_EMUL_DO_READ;
+		break;
+	}
+	default:
+		debug("Command not supported: %x\n", req->cmd[0]);
+		ret = -EPROTONOSUPPORT;
+	}
+	if (ret >= 0)
+		info->phase = info->transfer_len ? SCSIPH_DATA : SCSIPH_STATUS;
+	log_debug("   - done %x: ret=%d\n", *req->cmd, ret);
+
+	return ret;
+}