[media] gspca-pac207: Add a led_invert module parameter

Some cams have their led connected in such a way that on = off and visa versa
unfortunately we cannot tell this from the driver in any way, so add a module
parameter for this.
Reported-by: Yuri Glushkov <yglushkov@yahoo.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/gspca/pac207.c

@@ -55,6 +55,11 @@ MODULE_LICENSE("GPL");
 
 #define PAC207_AUTOGAIN_DEADZONE	30
 
+/* global parameters */
+static int led_invert;
+module_param(led_invert, int, 0644);
+MODULE_PARM_DESC(led_invert, "Invert led");
+
 /* specific webcam descriptor */
 struct sd {
 	struct gspca_dev gspca_dev;		/* !! must be the first item */
@@ -187,10 +192,14 @@ static int sd_config(struct gspca_dev *gspca_dev,
 /* this function is called at probe and resume time */
 static int sd_init(struct gspca_dev *gspca_dev)
 {
-	pac207_write_reg(gspca_dev, 0x41, 0x00);
-				/* Bit_0=Image Format,
-				 * Bit_1=LED,
-				 * Bit_2=Compression test mode enable */
+	u8 mode;
+
+	/* mode: Image Format (Bit 0), LED (1), Compr. test mode (2) */
+	if (led_invert)
+		mode = 0x02;
+	else
+		mode = 0x00;
+	pac207_write_reg(gspca_dev, 0x41, mode);
 	pac207_write_reg(gspca_dev, 0x0f, 0x00); /* Power Control */
 
 	return gspca_dev->usb_err;
@@ -303,7 +312,11 @@ static int sd_start(struct gspca_dev *gspca_dev)
 	pac207_write_reg(gspca_dev, 0x02,
 		v4l2_ctrl_g_ctrl(gspca_dev->exposure)); /* PXCK = 12MHz /n */
 
-	mode = 0x02; /* Image Format (Bit 0), LED (1), Compr. test mode (2) */
+	/* mode: Image Format (Bit 0), LED (1), Compr. test mode (2) */
+	if (led_invert)
+		mode = 0x00;
+	else
+		mode = 0x02;
 	if (gspca_dev->width == 176) {	/* 176x144 */
 		mode |= 0x01;
 		PDEBUG(D_STREAM, "pac207_start mode 176x144");
@@ -325,8 +338,15 @@ static int sd_start(struct gspca_dev *gspca_dev)
 
 static void sd_stopN(struct gspca_dev *gspca_dev)
 {
+	u8 mode;
+
+	/* mode: Image Format (Bit 0), LED (1), Compr. test mode (2) */
+	if (led_invert)
+		mode = 0x02;
+	else
+		mode = 0x00;
 	pac207_write_reg(gspca_dev, 0x40, 0x00); /* Stop ISO pipe */
-	pac207_write_reg(gspca_dev, 0x41, 0x00); /* Turn of LED */
+	pac207_write_reg(gspca_dev, 0x41, mode); /* Turn off LED */
 	pac207_write_reg(gspca_dev, 0x0f, 0x00); /* Power Control */
 }