USB: ati_remote2: Add channel support

Add logical channel support for ATI Remote Wonder II

The ATI Remote Wonder II can be configured with one of 16 unique logical
channels. Allowing up to 16 remotes to be used independently within
range of each other. This change adds functionality to configure the
receiver and filter the input data to respond or exclude remotes
configured with different logical channels.

Signed-off-by: Peter Stokes <[e-mail]>
Acked-by: Ville Syrjala <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/input/ati_remote2.c

···
  * ati_remote2 - ATI/Philips USB RF remote driver
  *
  * Copyright (C) 2005 Ville Syrjala <[e-mail]>
+ * Copyright (C) 2007 Peter Stokes <[e-mail]>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2
···
 #include <linux/usb/input.h>
 
 #define DRIVER_DESC    "ATI/Philips USB RF remote driver"
-#define DRIVER_VERSION "0.1"
+#define DRIVER_VERSION "0.2"
 
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_VERSION(DRIVER_VERSION);
 MODULE_AUTHOR("Ville Syrjala <[e-mail]>");
 MODULE_LICENSE("GPL");
+
+/*
+ * ATI Remote Wonder II Channel Configuration
+ *
+ * The remote control can by assigned one of sixteen "channels" in order to facilitate
+ * the use of multiple remote controls within range of each other.
+ * A remote's "channel" may be altered by pressing and holding the "PC" button for
+ * approximately 3 seconds, after which the button will slowly flash the count of the
+ * currently configured "channel", using the numeric keypad enter a number between 1 and
+ * 16 and then the "PC" button again, the button will slowly flash the count of the
+ * newly configured "channel".
+ */
+
+static unsigned int channel_mask = 0xFFFF;
+module_param(channel_mask, uint, 0644);
+MODULE_PARM_DESC(channel_mask, "Bitmask of channels to accept <15:Channel16>...<1:Channel2><0:Channel1>");
 
 static unsigned int mode_mask = 0x1F;
 module_param(mode_mask, uint, 0644);
···
 {
 	struct input_dev *idev = ar2->idev;
 	u8 *data = ar2->buf[0];
+	int channel, mode;
 
-	if (data[0] > 4) {
+	channel = data[0] >> 4;
+
+	if (!((1 << channel) & channel_mask))
+		return;
+
+	mode = data[0] & 0x0F;
+
+	if (mode > 4) {
 		dev_err(&ar2->intf[0]->dev,
 			"Unknown mode byte (%02x %02x %02x %02x)\n",
 			data[3], data[2], data[1], data[0]);
 		return;
 	}
 
-	if (!((1 << data[0]) & mode_mask))
+	if (!((1 << mode) & mode_mask))
 		return;
 
 	input_event(idev, EV_REL, REL_X, (s8) data[1]);
···
 {
 	struct input_dev *idev = ar2->idev;
 	u8 *data = ar2->buf[1];
-	int hw_code, index;
+	int channel, mode, hw_code, index;
 
-	if (data[0] > 4) {
+	channel = data[0] >> 4;
+
+	if (!((1 << channel) & channel_mask))
+		return;
+
+	mode = data[0] & 0x0F;
+
+	if (mode > 4) {
 		dev_err(&ar2->intf[1]->dev,
 			"Unknown mode byte (%02x %02x %02x %02x)\n",
 			data[3], data[2], data[1], data[0]);
···
 		 * events for the mouse pad so we filter out any subsequent
 		 * events from the same mode key.
 		 */
-		if (ar2->mode == data[0])
+		if (ar2->mode == mode)
 			return;
 
 		if (data[1] == 0)
-			ar2->mode = data[0];
+			ar2->mode = mode;
 
-		hw_code |= data[0] << 8;
+		hw_code |= mode << 8;
 	}
 
-	if (!((1 << data[0]) & mode_mask))
+	if (!((1 << mode) & mode_mask))
 		return;
 
 	index = ati_remote2_lookup(hw_code);
···
 	}
 }
 
+static int ati_remote2_setup(struct ati_remote2 *ar2)
+{
+	int r, i, channel;
+
+	/*
+	 * Configure receiver to only accept input from remote "channel"
+	 *  channel == 0  -> Accept input from any remote channel
+	 *  channel == 1  -> Only accept input from remote channel 1
+	 *  channel == 2  -> Only accept input from remote channel 2
+	 *  ...
+	 *  channel == 16 -> Only accept input from remote channel 16
+	 */
+
+	channel = 0;
+	for (i = 0; i < 16; i++) {
+		if ((1 << i) & channel_mask) {
+			if (!(~(1 << i) & 0xFFFF & channel_mask))
+				channel = i + 1;
+			break;
+		}
+	}
+
+	r = usb_control_msg(ar2->udev, usb_sndctrlpipe(ar2->udev, 0),
+			    0x20,
+			    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+			    channel, 0x0, NULL, 0, USB_CTRL_SET_TIMEOUT);
+	if (r) {
+		dev_err(&ar2->udev->dev, "%s - failed to set channel due to error: %d\n",
+			__FUNCTION__, r);
+		return r;
+	}
+
+	return 0;
+}
+
 static int ati_remote2_probe(struct usb_interface *interface, const struct usb_device_id *id)
 {
 	struct usb_device *udev = interface_to_usbdev(interface);
···
 	ar2->ep[1] = &alt->endpoint[0].desc;
 
 	r = ati_remote2_urb_init(ar2);
+	if (r)
+		goto fail2;
+
+	r = ati_remote2_setup(ar2);
 	if (r)
 		goto fail2;