[media] gspca_cpia1: Add support for button

Not only the qx3 microscope has a button, but some cameras too. Tested
with the Trust sp@cecam 100 (and with a creative and ezcam without button).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/cpia1.c

@@ -28,6 +28,7 @@
 
 #define MODULE_NAME "cpia1"
 
+#include <linux/input.h>
 #include "gspca.h"
 
 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
@@ -653,10 +654,15 @@ static int do_command(struct gspca_dev *gspca_dev, u16 command,
 		break;
 
 	case CPIA_COMMAND_ReadMCPorts:
-		if (!sd->params.qx3.qx3_detected)
-			break;
 		/* test button press */
-		sd->params.qx3.button = ((gspca_dev->usb_buf[1] & 0x02) == 0);
+		a = ((gspca_dev->usb_buf[1] & 0x02) == 0);
+		if (a != sd->params.qx3.button) {
+#if defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+			input_report_key(gspca_dev->input_dev, KEY_CAMERA, a);
+			input_sync(gspca_dev->input_dev);
+#endif
+	        	sd->params.qx3.button = a;
+		}
 		if (sd->params.qx3.button) {
 			/* button pressed - unlock the latch */
 			do_command(gspca_dev, CPIA_COMMAND_WriteMCPort,
@@ -1738,6 +1744,8 @@ static int sd_start(struct gspca_dev *gspca_dev)
 
 static void sd_stopN(struct gspca_dev *gspca_dev)
 {
+	struct sd *sd = (struct sd *) gspca_dev;
+
 	command_pause(gspca_dev);
 
 	/* save camera state for later open (developers guide ch 3.5.3) */
@@ -1748,6 +1756,17 @@ static void sd_stopN(struct gspca_dev *gspca_dev)
 
 	/* Update the camera status */
 	do_command(gspca_dev, CPIA_COMMAND_GetCameraStatus, 0, 0, 0, 0);
+
+#if defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+	/* If the last button state is pressed, release it now! */
+	if (sd->params.qx3.button) {
+		/* The camera latch will hold the pressed state until we reset
+		   the latch, so we do not reset sd->params.qx3.button now, to
+		   avoid a false keypress being reported the next sd_start */
+		input_report_key(gspca_dev->input_dev, KEY_CAMERA, 0);
+		input_sync(gspca_dev->input_dev);
+	}
+#endif
 }
 
 /* this function is called at probe and resume time */
@@ -1852,8 +1871,7 @@ static void sd_dq_callback(struct gspca_dev *gspca_dev)
 
 	/* Update our knowledge of the camera state */
 	do_command(gspca_dev, CPIA_COMMAND_GetExposure, 0, 0, 0, 0);
-	if (sd->params.qx3.qx3_detected)
-		do_command(gspca_dev, CPIA_COMMAND_ReadMCPorts, 0, 0, 0, 0);
+	do_command(gspca_dev, CPIA_COMMAND_ReadMCPorts, 0, 0, 0, 0);
 }
 
 static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val)
@@ -2085,6 +2103,9 @@ static const struct sd_desc sd_desc = {
 	.dq_callback = sd_dq_callback,
 	.pkt_scan = sd_pkt_scan,
 	.querymenu = sd_querymenu,
+#if defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
+	.other_input = 1,
+#endif
 };
 
 /* -- module initialisation -- */