refactor(core/usbd_core): process string internal, you can use like \"cherryusb\" now

4 files changed, 48 insertions, 75 deletions

diff --git a/cherryusb_config_template.h b/cherryusb_config_template.h
index 2128480f..5e5a5829 100644
--- a/cherryusb_config_template.h
+++ b/cherryusb_config_template.h
@@ -33,6 +33,10 @@
 
 /* ================= USB Device Stack Configuration ================ */
 
+#ifndef CONFIG_USBDEV_STRING_LANGID
+#define CONFIG_USBDEV_STRING_LANGID 0x0409
+#endif
+
 /* Ep0 in and out transfer buffer */
 #ifndef CONFIG_USBDEV_REQUEST_BUFFER_LEN
 #define CONFIG_USBDEV_REQUEST_BUFFER_LEN 512
diff --git a/core/usbd_core.c b/core/usbd_core.c
index 2a8903c5..042b72e0 100644
--- a/core/usbd_core.c
+++ b/core/usbd_core.c
@@ -18,6 +18,10 @@
 #define INTF_DESC_bInterfaceNumber  2 /** Interface number offset */
 #define INTF_DESC_bAlternateSetting 3 /** Alternate setting offset */
 
+#ifndef CONFIG_USBDEV_STRING_LANGID
+#define CONFIG_USBDEV_STRING_LANGID 0x0409
+#endif
+
 struct usbd_tx_rx_msg {
     uint8_t ep;
     uint8_t ep_mult;
@@ -151,6 +155,7 @@ static bool usbd_get_descriptor(uint8_t busid, uint16_t type_index, uint8_t **da
     uint8_t index = 0U;
     bool found = true;
     uint32_t desc_len = 0;
+    const char *string = NULL;
     const uint8_t *desc = NULL;
 
     type = HI_BYTE(type_index);
@@ -186,12 +191,40 @@ static bool usbd_get_descriptor(uint8_t busid, uint16_t type_index, uint8_t **da
                 desc = (uint8_t *)g_usbd_core[busid].descriptors->msosv1_descriptor->string;
                 desc_len = g_usbd_core[busid].descriptors->msosv1_descriptor->string[0];
             } else {
-                desc = g_usbd_core[busid].descriptors->string_descriptor_callback(g_usbd_core[busid].speed, index);
-                if (desc == NULL) {
+                if (index == USB_STRING_LANGID_INDEX) {
+                    uint16_t STRING_LANGID = CONFIG_USBDEV_STRING_LANGID;
+
+                    (*data)[0] = 0x04;
+                    (*data)[1] = USB_DESCRIPTOR_TYPE_STRING;
+                    (*data)[2] = (uint8_t)(STRING_LANGID & 0xff);
+                    (*data)[3] = (uint8_t)((STRING_LANGID & 0xff00) >> 8);
+
+                    *len = 4;
+                    return true;
+                }
+                string = g_usbd_core[busid].descriptors->string_descriptor_callback(g_usbd_core[busid].speed, index);
+                if (string == NULL) {
                     found = false;
                     break;
                 }
-                desc_len = desc[0];
+
+                uint16_t str_size = strlen(string);
+                uint16_t total_size = 2 * str_size + 2;
+                if (total_size > CONFIG_USBDEV_REQUEST_BUFFER_LEN) {
+                    USB_LOG_ERR("string size overflow\r\n");
+                    return false;
+                }
+
+                (*data)[0] = total_size;
+                (*data)[1] = USB_DESCRIPTOR_TYPE_STRING;
+
+                for (uint16_t i = 0; i < str_size; i++) {
+                    (*data)[2 * i + 2] = string[i];
+                    (*data)[2 * i + 3] = 0x00;
+                }
+
+                *len = total_size;
+                return true;
             }
             break;
         case USB_DESCRIPTOR_TYPE_DEVICE_QUALIFIER:
@@ -236,7 +269,7 @@ static bool usbd_get_descriptor(uint8_t busid, uint16_t type_index, uint8_t **da
         /* nothing found */
         USB_LOG_ERR("descriptor <type:%x,index:%x> not found!\r\n", type, index);
     } else {
-        *data = desc;
+        *data = (uint8_t *)desc;
         //memcpy(*data, desc, desc_len);
         *len = desc_len;
     }
diff --git a/core/usbd_core.h b/core/usbd_core.h
index f825b41b..a1a943ec 100644
--- a/core/usbd_core.h
+++ b/core/usbd_core.h
@@ -67,7 +67,7 @@ struct usb_descriptor {
     const uint8_t *(*config_descriptor_callback)(uint8_t speed);
     const uint8_t *(*device_quality_descriptor_callback)(uint8_t speed);
     const uint8_t *(*other_speed_descriptor_callback)(uint8_t speed);
-    const uint8_t *(*string_descriptor_callback)(uint8_t speed, uint8_t index);
+    const char *(*string_descriptor_callback)(uint8_t speed, uint8_t index);
     const struct usb_msosv1_descriptor *msosv1_descriptor;
     const struct usb_msosv2_descriptor *msosv2_descriptor;
     const struct usb_webusb_url_ex_descriptor *webusb_url_descriptor;
diff --git a/demo/cdc_acm_msc_template.c b/demo/cdc_acm_msc_template.c
index 3d78e4cc..a617ed30 100644
--- a/demo/cdc_acm_msc_template.c
+++ b/demo/cdc_acm_msc_template.c
@@ -62,76 +62,12 @@ static const uint8_t device_quality_descriptor[] = {
     0x00,
 };
 
-static const uint8_t string0_descriptor[] = {
-    ///////////////////////////////////////
-    /// string0 descriptor
-    ///////////////////////////////////////
-    USB_LANGID_INIT(USBD_LANGID_STRING),
-};
-
-static const uint8_t string1_descriptor[] = {
-    ///////////////////////////////////////
-    /// string1 descriptor
-    ///////////////////////////////////////
-    0x14,                       /* bLength */
-    USB_DESCRIPTOR_TYPE_STRING, /* bDescriptorType */
-    'C', 0x00,                  /* wcChar0 */
-    'h', 0x00,                  /* wcChar1 */
-    'e', 0x00,                  /* wcChar2 */
-    'r', 0x00,                  /* wcChar3 */
-    'r', 0x00,                  /* wcChar4 */
-    'y', 0x00,                  /* wcChar5 */
-    'U', 0x00,                  /* wcChar6 */
-    'S', 0x00,                  /* wcChar7 */
-    'B', 0x00,                  /* wcChar8 */
+static const char *string_descriptors[] = {
+    "CherryUSB",                  /* Manufacturer */
+    "CherryUSB CDC DEMO",         /* Product */
+    "2022123456",                 /* Serial Number */
 };
 
-static const uint8_t string2_descriptor[] = {
-    ///////////////////////////////////////
-    /// string2 descriptor
-    ///////////////////////////////////////
-    0x26,                       /* bLength */
-    USB_DESCRIPTOR_TYPE_STRING, /* bDescriptorType */
-    'C', 0x00,                  /* wcChar0 */
-    'h', 0x00,                  /* wcChar1 */
-    'e', 0x00,                  /* wcChar2 */
-    'r', 0x00,                  /* wcChar3 */
-    'r', 0x00,                  /* wcChar4 */
-    'y', 0x00,                  /* wcChar5 */
-    'U', 0x00,                  /* wcChar6 */
-    'S', 0x00,                  /* wcChar7 */
-    'B', 0x00,                  /* wcChar8 */
-    ' ', 0x00,                  /* wcChar9 */
-    'C', 0x00,                  /* wcChar10 */
-    '-', 0x00,                  /* wcChar11 */
-    'M', 0x00,                  /* wcChar12 */
-    ' ', 0x00,                  /* wcChar13 */
-    'D', 0x00,                  /* wcChar14 */
-    'E', 0x00,                  /* wcChar15 */
-    'M', 0x00,                  /* wcChar16 */
-    'O', 0x00,                  /* wcChar17 */
-};
-
-static const uint8_t string3_descriptor[] = {
-    ///////////////////////////////////////
-    /// string3 descriptor
-    ///////////////////////////////////////
-    0x16,                       /* bLength */
-    USB_DESCRIPTOR_TYPE_STRING, /* bDescriptorType */
-    '2', 0x00,                  /* wcChar0 */
-    '0', 0x00,                  /* wcChar1 */
-    '2', 0x00,                  /* wcChar2 */
-    '2', 0x00,                  /* wcChar3 */
-    '1', 0x00,                  /* wcChar4 */
-    '2', 0x00,                  /* wcChar5 */
-    '3', 0x00,                  /* wcChar6 */
-    '4', 0x00,                  /* wcChar7 */
-    '5', 0x00,                  /* wcChar8 */
-    '6', 0x00,                  /* wcChar9 */
-};
-
-static const uint8_t *string_descriptors[4] = { string0_descriptor, string1_descriptor, string2_descriptor, string3_descriptor };
-
 static const uint8_t *device_descriptor_callback(uint8_t speed)
 {
     return device_descriptor;
@@ -147,12 +83,12 @@ static const uint8_t *device_quality_descriptor_callback(uint8_t speed)
     return device_quality_descriptor;
 }
 
-static const uint8_t *string_descriptor_callback(uint8_t speed, uint8_t index)
+static const char *string_descriptor_callback(uint8_t speed, uint8_t index)
 {
     if (index > 3) {
         return NULL;
     }
-    return string_descriptors[index];
+    return string_descriptors[index - 1];
 }
 
 const struct usb_descriptor cdc_msc_descriptor = {