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 2505117e88e8bad0f1ce98a49498731634ceaf88..8f3659b65f5313303140c7f56100ea4c8cb30b1a 100644 (file)
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -311,11 +311,7 @@ struct fsg_common {
        /* 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 @@ static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
        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 @@ static ssize_t fsg_lun_opts_nofua_store(struct config_item *item,
 
 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 b6a9918eaefb9306258e2476d351bc95190c0177..d3902313b8ac44dd2a53ba16b346b0d585c3f2e1 100644 (file)
--- a/drivers/usb/gadget/function/f_mass_storage.h
+++ b/drivers/usb/gadget/function/f_mass_storage.h
@@ -100,6 +100,7 @@ struct fsg_lun_config {
        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 990df221c6299a2cd9d2ecb9aab54fda5447560e..8fbf6861690d2f6ae20d33d7499003ad887ae835 100644 (file)
--- a/drivers/usb/gadget/function/storage_common.c
+++ b/drivers/usb/gadget/function/storage_common.c
@@ -369,6 +369,12 @@ ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf)
 }
 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 @@ ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf,
 }
 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 c3544e61da6690f2b377e0a8e2cc8e7f835389ea..e69848994cb46488d1685efbf7565504c5c6947d 100644 (file)
--- a/drivers/usb/gadget/function/storage_common.h
+++ b/drivers/usb/gadget/function/storage_common.h
@@ -88,6 +88,12 @@ do {                                                                 \
 #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 fsg_lun {
        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_ro(struct fsg_lun *curlun, char *buf);
 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 @@ ssize_t fsg_store_cdrom(struct fsg_lun *curlun, struct rw_semaphore *filesem,
                        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 */