usb_hid.set_interface_name: use port_malloc to allocate memory for interface name

Author: MariuszCwikla

shared-bindings/usb_hid/__init__.c

@@ -156,12 +156,10 @@ STATIC mp_obj_t usb_hid_get_boot_device(void) {
 MP_DEFINE_CONST_FUN_OBJ_0(usb_hid_get_boot_device_obj, usb_hid_get_boot_device);
 
 
-//| def set_interface_name(
-//|     interface_name: str
-//| ) -> None:
+//| def set_interface_name(interface_name: str) -> None:
 //|     """Override HID interface name in the USB Interface Descriptor.
 //|
-//|     `interface_name` must be an ASCII string (or buffer) of at most 126.
+//|     ``interface_name`` must be an ASCII string (or buffer) of at most 126.
 //|
 //|     This method must be called in boot.py to have any effect.
 //|
@@ -179,8 +177,12 @@ STATIC mp_obj_t usb_hid_set_interface_name(size_t n_args, const mp_obj_t *pos_ar
     mp_buffer_info_t interface_name;
     mp_get_buffer_raise(args[0].u_obj, &interface_name, MP_BUFFER_READ);
     mp_arg_validate_length_range(interface_name.len, 1, 126, MP_QSTR_interface_name);
-    memcpy(usb_hid_interface_name_obj.interface_name, interface_name.buf, interface_name.len);
-    usb_hid_interface_name_obj.interface_name[interface_name.len] = 0;
+
+    if (custom_usb_hid_interface_name == NULL) {
+        custom_usb_hid_interface_name = port_malloc(sizeof(char) * 128, false);
+    }
+    memcpy(custom_usb_hid_interface_name, interface_name.buf, interface_name.len);
+    custom_usb_hid_interface_name[interface_name.len] = 0;
 
     return mp_const_none;
 }

shared-module/usb_hid/Device.c

@@ -164,9 +164,7 @@ const usb_hid_device_obj_t usb_hid_device_consumer_control_obj = {
     .out_report_lengths = { 0, },
 };
 
-usb_hid_interface_name_t usb_hid_interface_name_obj = {
-    .interface_name = USB_INTERFACE_NAME " HID",
-};
+char *custom_usb_hid_interface_name;
 
 STATIC size_t get_report_id_idx(usb_hid_device_obj_t *self, size_t report_id) {
     for (size_t i = 0; i < self->num_report_ids; i++) {

shared-module/usb_hid/Device.h

@@ -54,10 +54,6 @@ extern const usb_hid_device_obj_t usb_hid_device_consumer_control_obj;
 
 void usb_hid_device_create_report_buffers(usb_hid_device_obj_t *self);
 
-typedef struct {
-    char interface_name[128];
-} usb_hid_interface_name_t;
-
-extern usb_hid_interface_name_t usb_hid_interface_name_obj;
+extern char *custom_usb_hid_interface_name;
 
 #endif /* SHARED_MODULE_USB_HID_DEVICE_H */

shared-module/usb_hid/__init__.c

@@ -165,6 +165,8 @@ size_t usb_hid_descriptor_length(void) {
 
 // This is the interface descriptor, not the report descriptor.
 size_t usb_hid_add_descriptor(uint8_t *descriptor_buf, descriptor_counts_t *descriptor_counts, uint8_t *current_interface_string, uint16_t report_descriptor_length, uint8_t boot_device) {
+    const char *usb_hid_interface_name;
+
     memcpy(descriptor_buf, usb_hid_descriptor_template, sizeof(usb_hid_descriptor_template));
 
     descriptor_buf[HID_DESCRIPTOR_INTERFACE_INDEX] = descriptor_counts->current_interface;
@@ -175,7 +177,12 @@ size_t usb_hid_add_descriptor(uint8_t *descriptor_buf, descriptor_counts_t *desc
         descriptor_buf[HID_DESCRIPTOR_INTERFACE_PROTOCOL_INDEX] = boot_device; // 1: keyboard, 2: mouse
     }
 
-    usb_add_interface_string(*current_interface_string, usb_hid_interface_name_obj.interface_name);
+    if (custom_usb_hid_interface_name == NULL) {
+        usb_hid_interface_name = USB_INTERFACE_NAME " HID";
+    } else {
+        usb_hid_interface_name = custom_usb_hid_interface_name;
+    }
+    usb_add_interface_string(*current_interface_string, usb_hid_interface_name);
     descriptor_buf[HID_DESCRIPTOR_INTERFACE_STRING_INDEX] = *current_interface_string;
     (*current_interface_string)++;