V4L/DVB (12239): em28xx: fix webcam scaling

While trying to fix an mt9v001 webcam, I noticed that HSCALE/VSCALE do
work with em28xx + webcam. The issue is that the scaling setup depends
on the number of visible rows/cols of the input image.

With mt9v011 (Silvercrest), the resolution is 640x480. So, the scaling
is different from a normal TV image (720x480 on NTSC). This were causing
a wrong scaling and a previous patch disabled scaling.

As each sensor have their different resolution setting, the xres/yres
should be adjusted accordingly with the input sensor.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

4 files changed, 18 insertions, 24 deletions

diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index 1318766b35bb..d4a7e6075cc9 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -58,8 +58,6 @@ static unsigned int card[]     = {[0 ... (EM28XX_MAXBOARDS - 1)] = UNSET };
 module_param_array(card,  int, NULL, 0444);
 MODULE_PARM_DESC(card,     "card type");
 
-#define MT9V011_VERSION                 0x8243
-
 /* Bitmask marking allocated devices from 0 to EM28XX_MAXBOARDS */
 static unsigned long em28xx_devused;
 
@@ -1730,10 +1728,12 @@ static int em28xx_hint_sensor(struct em28xx *dev)
         version = be16_to_cpu(version_be);
 
         switch (version) {
-        case MT9V011_VERSION:
+        case 0x8243:            /* mt9v011 640x480 1.3 Mpix sensor */
                 dev->model = EM2820_BOARD_SILVERCREST_WEBCAM;
                 sensor_name = "mt9v011";
                 dev->em28xx_sensor = EM28XX_MT9V011;
+                dev->sensor_xres = 640;
+                dev->sensor_yres = 480;
                 break;
         default:
                 printk("Unknown Micron Sensor 0x%04x\n", be16_to_cpu(version));
diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index 8649bdb7eb91..c7fcce713945 100644
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -707,10 +707,7 @@ static int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v)
         u8 mode;
         /* the em2800 scaler only supports scaling down to 50% */
 
-        if (dev->board.is_webcam) {
-                /* FIXME: Don't use the scaler yet */
-                mode = 0;
-        } else if (dev->board.is_em2800) {
+        if (dev->board.is_em2800) {
                 mode = (v ? 0x20 : 0x00) | (h ? 0x10 : 0x00);
         } else {
                 u8 buf[2];
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index 89ab2e3b9a2c..ff37b4c15f44 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -657,8 +657,8 @@ static void get_scale(struct em28xx *dev,
                         unsigned int width, unsigned int height,
                         unsigned int *hscale, unsigned int *vscale)
 {
-        unsigned int          maxw   = norm_maxw(dev);
-        unsigned int          maxh   = norm_maxh(dev);
+        unsigned int          maxw = norm_maxw(dev);
+        unsigned int          maxh = norm_maxh(dev);
 
         *hscale = (((unsigned long)maxw) << 12) / width - 4096L;
         if (*hscale >= 0x4000)
@@ -726,11 +726,7 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
                 return -EINVAL;
         }
 
-        if (dev->board.is_webcam) {
-                /* FIXME: This is the only supported fmt */
-                width  = 640;
-                height = 480;
-        } else if (dev->board.is_em2800) {
+        if (dev->board.is_em2800) {
                 /* the em2800 can only scale down to 50% */
                 height = height > (3 * maxh / 4) ? maxh : maxh / 2;
                 width = width > (3 * maxw / 4) ? maxw : maxw / 2;
@@ -767,12 +763,6 @@ static int em28xx_set_video_format(struct em28xx *dev, unsigned int fourcc,
 {
         struct em28xx_fmt     *fmt;
 
-        /* FIXME: This is the only supported fmt */
-        if (dev->board.is_webcam) {
-                width  = 640;
-                height = 480;
-        }
-
         fmt = format_by_fourcc(fourcc);
         if (!fmt)
                 return -EINVAL;
diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 655dd78cc07b..71444ddbe40c 100644
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -479,6 +479,7 @@ struct em28xx {
         struct em28xx_board board;
 
         enum em28xx_sensor em28xx_sensor;
+        int sensor_xres, sensor_yres;
 
         unsigned int stream_on:1;       /* Locks streams */
         unsigned int has_audio_class:1;
@@ -760,17 +761,23 @@ static inline int em28xx_gamma_set(struct em28xx *dev, s32 val)
 /*FIXME: maxw should be dependent of alt mode */
 static inline unsigned int norm_maxw(struct em28xx *dev)
 {
+        if (dev->board.is_webcam)
+                return dev->sensor_xres;
+
         if (dev->board.max_range_640_480)
                 return 640;
-        else
-                return 720;
+
+        return 720;
 }
 
 static inline unsigned int norm_maxh(struct em28xx *dev)
 {
+        if (dev->board.is_webcam)
+                return dev->sensor_yres;
+
         if (dev->board.max_range_640_480)
                 return 480;
-        else
-                return (dev->norm & V4L2_STD_625_50) ? 576 : 480;
+
+        return (dev->norm & V4L2_STD_625_50) ? 576 : 480;
 }
 #endif