usb: gadget: Add per-lun inquiry string
Introduce an attribute "inquiry_string" to the lun.
In some environments, e. g. BIOS boot menus, the inquiry string
is the only information about devices presented to the user. The
default string depends on the "cdrom" bit of the first lun as
well as the kernel version and allows no further customization.
So without access to the client it is not obvious which gadget is
active at a given point and what any of the available luns might
contain.
If "inquiry_string" is ignored or set to the empty string, the
old behavior is preserved.
Signed-off-by: Philipp Gesang <philipp.gesang@intra2net.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index 2505117..8f3659b 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -311,11 +311,7 @@
/* Gadget's private data. */
void *private_data;
- /*
- * Vendor (8 chars), product (16 chars), release (4
- * hexadecimal digits) and NUL byte
- */
- char inquiry_string[8 + 16 + 4 + 1];
+ char inquiry_string[INQUIRY_STRING_LEN];
struct kref ref;
};
@@ -1107,7 +1103,12 @@
buf[5] = 0; /* No special options */
buf[6] = 0;
buf[7] = 0;
- memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
+ if (curlun->inquiry_string[0])
+ memcpy(buf + 8, curlun->inquiry_string,
+ sizeof(curlun->inquiry_string));
+ else
+ memcpy(buf + 8, common->inquiry_string,
+ sizeof(common->inquiry_string));
return 36;
}
@@ -3209,12 +3210,27 @@
CONFIGFS_ATTR(fsg_lun_opts_, nofua);
+static ssize_t fsg_lun_opts_inquiry_string_show(struct config_item *item,
+ char *page)
+{
+ return fsg_show_inquiry_string(to_fsg_lun_opts(item)->lun, page);
+}
+
+static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ return fsg_store_inquiry_string(to_fsg_lun_opts(item)->lun, page, len);
+}
+
+CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string);
+
static struct configfs_attribute *fsg_lun_attrs[] = {
&fsg_lun_opts_attr_file,
&fsg_lun_opts_attr_ro,
&fsg_lun_opts_attr_removable,
&fsg_lun_opts_attr_cdrom,
&fsg_lun_opts_attr_nofua,
+ &fsg_lun_opts_attr_inquiry_string,
NULL,
};
diff --git a/drivers/usb/gadget/function/f_mass_storage.h b/drivers/usb/gadget/function/f_mass_storage.h
index b6a9918..d390231 100644
--- a/drivers/usb/gadget/function/f_mass_storage.h
+++ b/drivers/usb/gadget/function/f_mass_storage.h
@@ -100,6 +100,7 @@
char removable;
char cdrom;
char nofua;
+ char inquiry_string[INQUIRY_STRING_LEN];
};
struct fsg_config {
diff --git a/drivers/usb/gadget/function/storage_common.c b/drivers/usb/gadget/function/storage_common.c
index 990df22..8fbf686 100644
--- a/drivers/usb/gadget/function/storage_common.c
+++ b/drivers/usb/gadget/function/storage_common.c
@@ -369,6 +369,12 @@
}
EXPORT_SYMBOL_GPL(fsg_show_removable);
+ssize_t fsg_show_inquiry_string(struct fsg_lun *curlun, char *buf)
+{
+ return sprintf(buf, "%s\n", curlun->inquiry_string);
+}
+EXPORT_SYMBOL_GPL(fsg_show_inquiry_string);
+
/*
* The caller must hold fsg->filesem for reading when calling this function.
*/
@@ -499,4 +505,22 @@
}
EXPORT_SYMBOL_GPL(fsg_store_removable);
+ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf,
+ size_t count)
+{
+ const size_t len = min(count, sizeof(curlun->inquiry_string));
+
+ if (len == 0 || buf[0] == '\n') {
+ curlun->inquiry_string[0] = 0;
+ } else {
+ snprintf(curlun->inquiry_string,
+ sizeof(curlun->inquiry_string), "%-28s", buf);
+ if (curlun->inquiry_string[len-1] == '\n')
+ curlun->inquiry_string[len-1] = ' ';
+ }
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(fsg_store_inquiry_string);
+
MODULE_LICENSE("GPL");
diff --git a/drivers/usb/gadget/function/storage_common.h b/drivers/usb/gadget/function/storage_common.h
index c3544e6..e698489 100644
--- a/drivers/usb/gadget/function/storage_common.h
+++ b/drivers/usb/gadget/function/storage_common.h
@@ -88,6 +88,12 @@
#define ASC(x) ((u8) ((x) >> 8))
#define ASCQ(x) ((u8) (x))
+/*
+ * Vendor (8 chars), product (16 chars), release (4 hexadecimal digits) and NUL
+ * byte
+ */
+#define INQUIRY_STRING_LEN ((size_t) (8 + 16 + 4 + 1))
+
struct fsg_lun {
struct file *filp;
loff_t file_length;
@@ -112,6 +118,7 @@
struct device dev;
const char *name; /* "lun.name" */
const char **name_pfx; /* "function.name" */
+ char inquiry_string[INQUIRY_STRING_LEN];
};
static inline bool fsg_lun_is_open(struct fsg_lun *curlun)
@@ -210,6 +217,7 @@
ssize_t fsg_show_nofua(struct fsg_lun *curlun, char *buf);
ssize_t fsg_show_file(struct fsg_lun *curlun, struct rw_semaphore *filesem,
char *buf);
+ssize_t fsg_show_inquiry_string(struct fsg_lun *curlun, char *buf);
ssize_t fsg_show_cdrom(struct fsg_lun *curlun, char *buf);
ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf);
ssize_t fsg_store_ro(struct fsg_lun *curlun, struct rw_semaphore *filesem,
@@ -221,5 +229,7 @@
const char *buf, size_t count);
ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
size_t count);
+ssize_t fsg_store_inquiry_string(struct fsg_lun *curlun, const char *buf,
+ size_t count);
#endif /* USB_STORAGE_COMMON_H */