ums: support multiple LUNs at once

Extend the ums command to accept a list of block devices. Each of these
will be exported as a separate LUN. An example use-case would be:

ums 0 mmc 0,0.1,0.2

... which would export LUNs for eMMC 0's user data, boot0, and boot1 HW
partitions. This is useful since it allows the host access to everything
on the eMMC without having to somehow stop the ums command from executing
and restart it with different parameters.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

2 files changed, 16 insertions, 13 deletions

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index ec1f23a..1ecb92a 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -444,8 +444,9 @@ static void set_bulk_out_req_length(struct fsg_common *common,
 
 /*-------------------------------------------------------------------------*/
 
-struct ums *ums;
-struct fsg_common *the_fsg_common;
+static struct ums *ums;
+static int ums_count;
+static struct fsg_common *the_fsg_common;
 
 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 {
@@ -772,7 +773,7 @@ static int do_read(struct fsg_common *common)
 		}
 
 		/* Perform the read */
-		rc = ums->read_sector(ums,
+		rc = ums[common->lun].read_sector(&ums[common->lun],
 				      file_offset / SECTOR_SIZE,
 				      amount / SECTOR_SIZE,
 				      (char __user *)bh->buf);
@@ -946,7 +947,7 @@ static int do_write(struct fsg_common *common)
 			amount = bh->outreq->actual;
 
 			/* Perform the write */
-			rc = ums->write_sector(ums,
+			rc = ums[common->lun].write_sector(&ums[common->lun],
 					       file_offset / SECTOR_SIZE,
 					       amount / SECTOR_SIZE,
 					       (char __user *)bh->buf);
@@ -1062,7 +1063,7 @@ static int do_verify(struct fsg_common *common)
 		}
 
 		/* Perform the read */
-		rc = ums->read_sector(ums,
+		rc = ums[common->lun].read_sector(&ums[common->lun],
 				      file_offset / SECTOR_SIZE,
 				      amount / SECTOR_SIZE,
 				      (char __user *)bh->buf);
@@ -1117,7 +1118,7 @@ static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
 	buf[4] = 31;		/* Additional length */
 				/* No special options */
 	sprintf((char *) (buf + 8), "%-8s%-16s%04x", (char*) vendor_id ,
-			ums->name, (u16) 0xffff);
+			ums[common->lun].name, (u16) 0xffff);
 
 	return 36;
 }
@@ -2456,7 +2457,7 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 	int nluns, i, rc;
 
 	/* Find out how many LUNs there should be */
-	nluns = 1;
+	nluns = ums_count;
 	if (nluns < 1 || nluns > FSG_MAX_LUNS) {
 		printf("invalid number of LUNs: %u\n", nluns);
 		return ERR_PTR(-EINVAL);
@@ -2501,7 +2502,7 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 	for (i = 0; i < nluns; i++) {
 		common->luns[i].removable = 1;
 
-		rc = fsg_lun_open(&common->luns[i], "");
+		rc = fsg_lun_open(&common->luns[i], ums[i].num_sectors, "");
 		if (rc)
 			goto error_luns;
 	}
@@ -2775,9 +2776,10 @@ int fsg_add(struct usb_configuration *c)
 	return fsg_bind_config(c->cdev, c, fsg_common);
 }
 
-int fsg_init(struct ums *ums_dev)
+int fsg_init(struct ums *ums_devs, int count)
 {
-	ums = ums_dev;
+	ums = ums_devs;
+	ums_count = count;
 
 	return 0;
 }
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index b55e40b..b6df130 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -564,7 +564,8 @@ static struct usb_gadget_strings	fsg_stringtab = {
  * the caller must own fsg->filesem for writing.
  */
 
-static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
+static int fsg_lun_open(struct fsg_lun *curlun, unsigned int num_sectors,
+			const char *filename)
 {
 	int				ro;
 
@@ -572,8 +573,8 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 	ro = curlun->initially_ro;
 
 	curlun->ro = ro;
-	curlun->file_length = ums->num_sectors << 9;
-	curlun->num_sectors = ums->num_sectors;
+	curlun->file_length = num_sectors << 9;
+	curlun->num_sectors = num_sectors;
 	debug("open backing file: %s\n", filename);
 
 	return 0;