USB: Add functionality to poll the USB keyboard via control EP

This allows the keyboard to avoid requests via Interrupt Endpoint altogether and
run all requests via Control Endpoint. This uses the Get_Report request.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Remy Bohmer <linux@bohmer.net>

Rebased on current code.

Signed-off-by: Remy Bohmer <linux@bohmer.net>

common/usb_kbd.c

@@ -98,6 +98,26 @@ static unsigned char usb_kbd_numkey_shifted[] = {
 	'|', '~', ':', '"', '~', '<', '>', '?'
 };
 
+static int usb_kbd_irq_worker(struct usb_device *dev);
+
+/******************************************************************
+ * Interrupt polling
+ ******************************************************************/
+static inline void usb_kbd_poll_for_event(struct usb_device *dev)
+{
+#if	defined(CONFIG_SYS_USB_EVENT_POLL)
+	usb_event_poll();
+	usb_kbd_irq_worker(dev);
+#elif	defined(CONFIG_SYS_USB_EVENT_POLL_VIA_CONTROL_EP)
+	struct usb_interface *iface;
+	iface = &dev->config.if_desc[0];
+	usb_get_report(dev, iface->desc.bInterfaceNumber,
+			1, 1, new, sizeof(new));
+	if (memcmp(old, new, sizeof(new)))
+		usb_kbd_irq_worker(dev);
+#endif
+}
+
 /******************************************************************
  * Queue handling
  ******************************************************************/
@@ -121,9 +141,14 @@ static void usb_kbd_put_queue(char data)
 /* test if a character is in the queue */
 static int usb_kbd_testc(void)
 {
-#ifdef CONFIG_SYS_USB_EVENT_POLL
-	usb_event_poll();
-#endif
+	struct stdio_dev *dev;
+	struct usb_device *usb_kbd_dev;
+
+	dev = stdio_get_by_name("usbkbd");
+	usb_kbd_dev = (struct usb_device *)dev->priv;
+
+	usb_kbd_poll_for_event(usb_kbd_dev);
+
 	if (usb_in_pointer == usb_out_pointer)
 		return 0; /* no data */
 	else
@@ -133,11 +158,16 @@ static int usb_kbd_testc(void)
 static int usb_kbd_getc(void)
 {
 	char c;
-	while (usb_in_pointer == usb_out_pointer) {
-#ifdef CONFIG_SYS_USB_EVENT_POLL
-		usb_event_poll();
-#endif
-	}
+
+	struct stdio_dev *dev;
+	struct usb_device *usb_kbd_dev;
+
+	dev = stdio_get_by_name("usbkbd");
+	usb_kbd_dev = (struct usb_device *)dev->priv;
+
+	while (usb_in_pointer == usb_out_pointer)
+		usb_kbd_poll_for_event(usb_kbd_dev);
+
 	if ((usb_out_pointer+1) == USB_KBD_BUFFER_LEN)
 		usb_out_pointer = 0;
 	else
@@ -323,15 +353,10 @@ static int usb_kbd_translate(unsigned char scancode, unsigned char modifier,
 }
 
 /* Interrupt service routine */
-static int usb_kbd_irq(struct usb_device *dev)
+static int usb_kbd_irq_worker(struct usb_device *dev)
 {
 	int i, res;
 
-	if ((dev->irq_status != 0) || (dev->irq_act_len != 8)) {
-		USB_KBD_PRINTF("usb_keyboard Error %lX, len %d\n",
-				dev->irq_status, dev->irq_act_len);
-		return 1;
-	}
 	res = 0;
 
 	switch (new[0]) {
@@ -362,6 +387,17 @@ static int usb_kbd_irq(struct usb_device *dev)
 	return 1; /* install IRQ Handler again */
 }
 
+static int usb_kbd_irq(struct usb_device *dev)
+{
+	if ((dev->irq_status != 0) || (dev->irq_act_len != 8)) {
+		USB_KBD_PRINTF("usb_keyboard Error %lX, len %d\n",
+				dev->irq_status, dev->irq_act_len);
+		return 1;
+	}
+
+	return usb_kbd_irq_worker(dev);
+}
+
 /* probes the USB device dev for keyboard type */
 static int usb_kbd_probe(struct usb_device *dev, unsigned int ifnum)
 {