# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1362425245 0
# Node ID a11494bd42ccad4c669f237a80c86a9f8113f91d
# Parent  26c62ea1aef90455d8da5375dcae620290f4bf76
Introduced a generic descriptor retrieval function, using it in device
initialisation and to get the available languages.
Made the display of language codes a separate function.

diff -r 26c62ea1aef9 -r a11494bd42cc test.c
--- a/test.c	Fri Mar 01 23:38:54 2013 +0000
+++ b/test.c	Mon Mar 04 19:27:25 2013 +0000
@@ -586,6 +586,43 @@
     setup[7] = length >> 8;
 }
 
+uint8_t usb_descriptor_size(uint8_t type)
+{
+    switch (type)
+    {
+        case USB_DT_DEVICE: return USB_DT_DEVICE_SIZE;
+        case USB_DT_CONFIG: return USB_DT_CONFIG_SIZE;
+        case USB_DT_STRING: return sizeof(struct usb_string_descriptor);
+        case USB_DT_INTERFACE: return USB_DT_INTERFACE_SIZE;
+        case USB_DT_ENDPOINT: return USB_DT_ENDPOINT_SIZE;
+        default: return 0;
+    }
+}
+
+uint8_t *max_get_descriptor(max_device *device, uint8_t type, uint8_t value, uint8_t index)
+{
+    static uint8_t data[64];
+    uint8_t len = 64, setup[8];
+
+    printf("Sending descriptor request to address %d, endpoint 0...\n", device->address);
+
+    max_write(MAX_REG_PERADDR, device->address);
+
+    setup_packet(setup, USB_ENDPOINT_IN, USB_REQ_GET_DESCRIPTOR, usb_descriptor_type(type) | value, index, 64);
+    max_control(setup);
+    if (!max_control_input(data, &len, device))
+    {
+        printf("Failed.\n");
+        return NULL;
+    }
+    max_control_status(true);
+
+    if (len >= usb_descriptor_size(type))
+        return data;
+    else
+        return NULL;
+}
+
 /**
  * Perform initialisation on a device, obtaining the device details and storing
  * this information in the device structure, returning true if successful and
@@ -593,23 +630,19 @@
  */
 bool max_init_device(max_device *device)
 {
-    uint8_t data[64], len = 64, setup[8];
+    struct usb_device_descriptor *desc;
 
     printf("Sending control request to address 0, endpoint 0...\n");
 
-    max_write(MAX_REG_PERADDR, 0);
+    device->address = 0;
 
     /* Send a "get descriptor" request for the device descriptor. */
 
-    setup_packet(setup, USB_ENDPOINT_IN, USB_REQ_GET_DESCRIPTOR, usb_descriptor_type(USB_DT_DEVICE), 0, USB_DT_DEVICE_SIZE);
-    max_control(setup);
-    if (!max_control_input(data, &len, device))
-        return false;
-    max_control_status(true);
+    desc = (struct usb_device_descriptor *) max_get_descriptor(device, USB_DT_DEVICE, 0, 0);
 
-    if (len >= sizeof(struct usb_device_descriptor))
+    if (desc != NULL)
     {
-        memcpy(&device->desc, data, sizeof(struct usb_device_descriptor));
+        memcpy(&device->desc, desc, sizeof(struct usb_device_descriptor));
         device->desc.bcdUSB = le16toh(device->desc.bcdUSB);
         device->desc.idVendor = le16toh(device->desc.idVendor);
         device->desc.idProduct = le16toh(device->desc.idProduct);
@@ -657,37 +690,20 @@
     max_control_status(false);
 }
 
-
-void max_get_descriptor(max_device *device)
+void usb_show_languages(uint8_t *data)
 {
-    uint8_t data[64], len = 64, setup[8];
-    struct usb_string_descriptor *desc;
+    struct usb_string_descriptor *desc = (struct usb_string_descriptor *) data;
     uint16_t *lang;
 
-    printf("Sending descriptor request to address %d, endpoint 0...\n", device->address);
-
-    max_write(MAX_REG_PERADDR, device->address);
-
-    setup_packet(setup, USB_ENDPOINT_IN, USB_REQ_GET_DESCRIPTOR, usb_descriptor_type(USB_DT_STRING), 0, 64);
-    max_control(setup);
-    if (!max_control_input(data, &len, device))
-    {
-        printf("Failed.\n");
+    if (data == NULL)
         return;
-    }
-    max_control_status(true);
 
-    if (len >= sizeof(struct usb_string_descriptor))
-    {
-        desc = (struct usb_string_descriptor *) data;
+    printf("bLength: %d\n", desc->bLength);
+    printf("bDescriptorType: %d\n", desc->bDescriptorType);
 
-        printf("bLength: %d\n", desc->bLength);
-        printf("bDescriptorType: %d\n", desc->bDescriptorType);
-
-        for (lang = desc->wData; lang < (uint16_t *) (data + desc->bLength); lang++)
-        {
-            printf("wLangId: %04x\n", le16toh(*lang));
-        }
+    for (lang = desc->wData; lang < (uint16_t *) (data + desc->bLength); lang++)
+    {
+        printf("wLangId: %04x\n", le16toh(*lang));
     }
 }
 
@@ -866,7 +882,7 @@
                 max_write(MAX_REG_MODE, max_read(MAX_REG_MODE, NULL) & ~MAX_MODE_SOFKAENAB);
                 max_set_address(&device);
                 devstate = MAX_DEVSTATE_READY;
-                max_get_descriptor(&device);
+                usb_show_languages(max_get_descriptor(&device, USB_DT_STRING, 0, 0));
                 printf("READY\n");
             }