[media] stk-webcam: Add an upside down dmi table, and add the Asus G1 to it

The stk-webcam module is inserted upside-down in some webcams, so we
need to de hflip and vflip by default on some models.
Note that this patch inverts the value of the controls as reported by
the control API in this case so that for the user they still make sense
(iow not doing any flipping from the ctrl API pov results in an upright
image).

Reported-by: Jose Gómez <adler@dreamcoder.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/stkwebcam/stk-webcam.c

@@ -28,6 +28,7 @@
 #include <linux/errno.h>
 #include <linux/slab.h>
 
+#include <linux/dmi.h>
 #include <linux/usb.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
@@ -38,12 +39,12 @@
 #include "stk-webcam.h"
 
 
-static bool hflip;
-module_param(hflip, bool, 0444);
+static int hflip = -1;
+module_param(hflip, int, 0444);
 MODULE_PARM_DESC(hflip, "Horizontal image flip (mirror). Defaults to 0");
 
-static bool vflip;
-module_param(vflip, bool, 0444);
+static int vflip = -1;
+module_param(vflip, int, 0444);
 MODULE_PARM_DESC(vflip, "Vertical image flip. Defaults to 0");
 
 static int debug;
@@ -62,6 +63,19 @@ static struct usb_device_id stkwebcam_table[] = {
 };
 MODULE_DEVICE_TABLE(usb, stkwebcam_table);
 
+/* The stk webcam laptop module is mounted upside down in some laptops :( */
+static const struct dmi_system_id stk_upside_down_dmi_table[] = {
+	{
+		.ident = "ASUS G1",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "G1")
+		}
+	},
+	{}
+};
+
+
 /*
  * Basic stuff
  */
@@ -817,10 +831,16 @@ static int stk_vidioc_g_ctrl(struct file *filp,
 		c->value = dev->vsettings.brightness;
 		break;
 	case V4L2_CID_HFLIP:
-		c->value = dev->vsettings.hflip;
+		if (dmi_check_system(stk_upside_down_dmi_table))
+			c->value = !dev->vsettings.hflip;
+		else
+			c->value = dev->vsettings.hflip;
 		break;
 	case V4L2_CID_VFLIP:
-		c->value = dev->vsettings.vflip;
+		if (dmi_check_system(stk_upside_down_dmi_table))
+			c->value = !dev->vsettings.vflip;
+		else
+			c->value = dev->vsettings.vflip;
 		break;
 	default:
 		return -EINVAL;
@@ -837,10 +857,16 @@ static int stk_vidioc_s_ctrl(struct file *filp,
 		dev->vsettings.brightness = c->value;
 		return stk_sensor_set_brightness(dev, c->value >> 8);
 	case V4L2_CID_HFLIP:
-		dev->vsettings.hflip = c->value;
+		if (dmi_check_system(stk_upside_down_dmi_table))
+			dev->vsettings.hflip = !c->value;
+		else
+			dev->vsettings.hflip = c->value;
 		return 0;
 	case V4L2_CID_VFLIP:
-		dev->vsettings.vflip = c->value;
+		if (dmi_check_system(stk_upside_down_dmi_table))
+			dev->vsettings.vflip = !c->value;
+		else
+			dev->vsettings.vflip = c->value;
 		return 0;
 	default:
 		return -EINVAL;
@@ -1276,8 +1302,18 @@ static int stk_camera_probe(struct usb_interface *interface,
 	dev->interface = interface;
 	usb_get_intf(interface);
 
-	dev->vsettings.vflip = vflip;
-	dev->vsettings.hflip = hflip;
+	if (hflip != -1)
+		dev->vsettings.hflip = hflip;
+	else if (dmi_check_system(stk_upside_down_dmi_table))
+		dev->vsettings.hflip = 1;
+	else
+		dev->vsettings.hflip = 0;
+	if (vflip != -1)
+		dev->vsettings.vflip = vflip;
+	else if (dmi_check_system(stk_upside_down_dmi_table))
+		dev->vsettings.vflip = 1;
+	else
+		dev->vsettings.vflip = 0;
 	dev->n_sbufs = 0;
 	set_present(dev);