Introduce Built-In CDROM (BICR) support.
This feature depends on USB_CONFIGFS_MASS_STORAGE option.
1. Some settings and new function is introduced for BICR.
2. Some work around for adapting Android settings is introduced as well.
Signed-off-by: Justin Hsieh <justinhsieh@xxxxxxxxxx>
Signed-off-by: Hakieyin Hsieh <hakieyin@xxxxxxxxx>
Signed-off-by: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx>
---
Changes for v2:
- Thanks for Peter's review.
- Fix typo in commit message.
- use variable common->bicr instead of IS_ENABLED().
- Fix #ifdef CONFIG_USB_CONFIGFS_BICR.
drivers/usb/gadget/Kconfig | 16 +++++++
drivers/usb/gadget/function/f_mass_storage.c | 49 +++++++++++++++++++-
drivers/usb/gadget/function/f_mass_storage.h | 5 +-
drivers/usb/gadget/function/storage_common.c | 23 +++++++++
4 files changed, 90 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 4dc4d48fe6a6..686ba01bedb5 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -188,6 +188,9 @@ config USB_F_RNDIS
config USB_F_MASS_STORAGE
tristate
+config USB_F_BICR
+ tristate
+
config USB_F_FS
tristate
@@ -357,6 +360,19 @@ config USB_CONFIGFS_MASS_STORAGE
device (in much the same way as the "loop" device driver),
specified as a module parameter or sysfs option.
+config USB_CONFIGFS_BICR
+ bool "Built-In CDROM emulation"
+ depends on USB_CONFIGFS
+ depends on BLOCK
+ depends on USB_CONFIGFS_MASS_STORAGE
+ select USB_F_BICR
+ help
+ The Build-In CDROM Gadget acts as a CDROM emulation disk drive.
+ It is based on kernel option "USB_CONFIGFS_MASS_STORAGE".
+ As its storage repository it can use a regular file or a block
+ device (in much the same way as the "loop" device driver),
+ specified as a module parameter or sysfs option.
+
config USB_CONFIGFS_F_LB_SS
bool "Loopback and sourcesink function (for testing)"
depends on USB_CONFIGFS
diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index 33c2264a0e35..9de1cd465635 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -315,6 +315,9 @@ struct fsg_common {
void *private_data;
char inquiry_string[INQUIRY_STRING_LEN];
+
+ /* For build-in CDROM */
+ u8 bicr;
};
struct fsg_dev {
@@ -369,6 +372,10 @@ static void set_bulk_out_req_length(struct fsg_common *common,
if (rem > 0)
length += common->bulk_out_maxpacket - rem;
bh->outreq->length = length;
+
+ /* some USB 2.0 hardware requires this setting */
+ if (common->bicr)
+ bh->outreq->short_not_ok = 1;
}
@@ -527,7 +534,16 @@ static int fsg_setup(struct usb_function *f,
w_length != 1)
return -EDOM;
VDBG(fsg, "get max LUN\n");
- *(u8 *)req->buf = _fsg_common_get_max_lun(fsg->common);
+ if (IS_ENABLED(USB_CONFIGFS_BICR) && fsg->common->bicr) {
+ /*
+ * When Built-In CDROM is enabled,
+ * we share only one LUN.
+ */
+ *(u8 *)req->buf = 0;
+ } else {
+ *(u8 *)req->buf = _fsg_common_get_max_lun(fsg->common);
+ }
+ INFO(fsg, "get max LUN = %d\n", *(u8 *)req->buf);
/* Respond with data/status */
req->length = min((u16)1, w_length);
@@ -1329,7 +1345,7 @@ static int do_start_stop(struct fsg_common *common)
}
/* Are we allowed to unload the media? */
- if (curlun->prevent_medium_removal) {
+ if (!curlun->nofua && curlun->prevent_medium_removal) {
LDBG(curlun, "unload attempt prevented\n");
curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
return -EINVAL;
@@ -2692,6 +2708,7 @@ int fsg_common_set_cdev(struct fsg_common *common,
common->ep0 = cdev->gadget->ep0;
common->ep0req = cdev->req;
common->cdev = cdev;
+ common->bicr = 0;
us = usb_gstrings_attach(cdev, fsg_strings_array,
ARRAY_SIZE(fsg_strings));
@@ -2895,6 +2912,33 @@ static void fsg_common_release(struct fsg_common *common)
kfree(common);
}
+#ifdef CONFIG_USB_CONFIGFS_BICR
+ssize_t fsg_bicr_show(struct fsg_common *common, char *buf)
+{
+ return sprintf(buf, "%d\n", common->bicr);
+}
+
+ssize_t fsg_bicr_store(struct fsg_common *common, const char *buf, size_t size)
+{
+ int ret;
+
+ ret = kstrtou8(buf, 10, &common->bicr);
+ if (ret)
+ return -EINVAL;
+
+ /* Set Lun[0] is a CDROM when enable bicr.*/
+ if (!strcmp(buf, "1"))
+ common->luns[0]->cdrom = 1;
+ else {
+ common->luns[0]->cdrom = 0;
+ common->luns[0]->blkbits = 0;
+ common->luns[0]->blksize = 0;
+ common->luns[0]->num_sectors = 0;
+ }
+
+ return size;
+}
+#endif
/*-------------------------------------------------------------------------*/
@@ -3463,6 +3507,7 @@ void fsg_config_from_params(struct fsg_config *cfg,
lun->ro = !!params->ro[i];
lun->cdrom = !!params->cdrom[i];
lun->removable = !!params->removable[i];
+ lun->nofua = !!params->nofua[i];
lun->filename =
params->file_count > i && params->file[i][0]
? params->file[i]
diff --git a/drivers/usb/gadget/function/f_mass_storage.h b/drivers/usb/gadget/function/f_mass_storage.h
index 3b8c4ce2a40a..7097e2ea5cc9 100644
--- a/drivers/usb/gadget/function/f_mass_storage.h
+++ b/drivers/usb/gadget/function/f_mass_storage.h
@@ -140,5 +140,8 @@ void fsg_common_set_inquiry_string(struct fsg_common *common, const char *vn,
void fsg_config_from_params(struct fsg_config *cfg,
const struct fsg_module_parameters *params,
unsigned int fsg_num_buffers);
-
+#ifdef CONFIG_USB_CONFIGFS_BICR
+ssize_t fsg_bicr_show(struct fsg_common *common, char *buf);
+ssize_t fsg_bicr_store(struct fsg_common *common, const char *buf, size_t size);
+#endif
#endif /* USB_F_MASS_STORAGE_H */
diff --git a/drivers/usb/gadget/function/storage_common.c b/drivers/usb/gadget/function/storage_common.c
index f7e6c42558eb..8fe96eeddf35 100644
--- a/drivers/usb/gadget/function/storage_common.c
+++ b/drivers/usb/gadget/function/storage_common.c
@@ -441,6 +441,29 @@ ssize_t fsg_store_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
return -EBUSY; /* "Door is locked" */
}
+ pr_notice("%s file=%s, count=%d, curlun->cdrom=%d\n",
+ __func__, buf, (int)count, curlun->cdrom);
+
+ /*
+ * WORKAROUND for Android:
+ * VOLD would clean the file path after switching to bicr.
+ * So when the lun is being a CD-ROM a.k.a. BICR.
+ * Don't clean the file path to empty.
+ */
+ if (curlun->cdrom == 1 && count == 1)
+ return count;
+
+ /*
+ * WORKAROUND: Should be closed the fsg lun for virtual cd-rom,
+ * when switch to other usb functions.
+ * Use the special keyword "off", because the init can
+ * not parse the char '\n' in rc file and write into the sysfs.
+ */
+ if (count == 3 &&
+ buf[0] == 'o' && buf[1] == 'f' && buf[2] == 'f' &&
+ fsg_lun_is_open(curlun))
+ ((char *) buf)[0] = 0;
+
/* Remove a trailing newline */
if (count > 0 && buf[count-1] == '\n')
((char *) buf)[count-1] = 0; /* Ugh! */
--
2.18.0
