usb_gadget: Retrieve device serial number

Serial number is retrieved from
/sys/firmware/devicetree/base/serial-number file.

Change-Id: I3e8251bd1ce916b72d45102017b3533420ef9f54
Signed-off-by: Paweł Szewczyk <p.szewczyk@samsung.com>

diff --git a/hw/usb_gadget/usb_gadget.c b/hw/usb_gadget/usb_gadget.c
index ad4513d..d1e6704 100755 (executable)
--- a/hw/usb_gadget/usb_gadget.c
+++ b/hw/usb_gadget/usb_gadget.c
@@ -20,6 +20,7 @@
 
 #include <hw/usb_gadget.h>
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <string.h>
@@ -122,11 +123,36 @@ out:
        return -ENOMEM;
 }
 
+#define SERIAL_FILE_PATH "/sys/firmware/devicetree/base/serial-number"
+#define LINE_LEN 64
+
+static int get_device_serial(char **out)
+{
+       FILE *fp;
+       char *line, *p;
+
+       fp = fopen(SERIAL_FILE_PATH, "r");
+       if (!fp)
+               return -1;
+
+       line = malloc(LINE_LEN);
+       p = fgets(line, LINE_LEN, fp);
+       fclose(fp);
+       if (p == NULL) {
+               free(line);
+               return -1;
+       }
+
+       *out = p;
+       return 0;
+}
+
 static int alloc_default_gadget(struct usb_gadget **_gadget)
 {
        struct usb_gadget *gadget;
        struct usb_gadget_strings *strs;
        struct usb_configuration **configs;
+       int ret;
 
        gadget = zalloc(sizeof(*gadget));
        if (!gadget)
@@ -143,7 +169,9 @@ static int alloc_default_gadget(struct usb_gadget **_gadget)
        strs[0].lang_code = 0x409;
        strs[0].manufacturer = strdup(DEFAULT_MANUFACTURER);
        strs[0].product = strdup(DEFAULT_PRODUCT);
-       strs[0].serial = strdup(DEFAULT_SERIAL);
+       ret = get_device_serial(&strs[0].serial);
+       if (ret < 0)
+               strs[0].serial = strdup(DEFAULT_SERIAL);
 
        if (!strs[0].manufacturer || !strs[0].product || !strs[0].serial)
                goto free_strs;