Fix the S-Video capture on August VGB100

Commit Message

Fabio Luongo Sept. 27, 2024, 1:38 p.m. UTC

There are three separate issues preventing color capture with S-Video
on August VGB100 with the cx231xx driver (same vid/pid as OTG102):

1. `cx231xx_set_decoder_video_input` is called with a u32 passed
   as its third argument, yet this functions expects a u8 instead.
   Some information about the configuration of the video mux is lost
   in the conversion, so that ch2 and ch3 do not get set by
   `cx231xx_afe_set_input_mux` (expecting a u32 but being passed a u8).

2. The input pin for the chroma signal is not correctly specified
   in cx231xx-cards.c, which can be verified by looking at the inf file
   coming with the VGB100 and OTG102' drivers for Windows.
   The mistake in the cx231xx driver likely stems from a wrong comment
   in the same file, suggesting VIN1_2 for chroma,
   while VIN3_2 is actually used.

3. Even after fixing the two issues above, the captured stream remains
   essentially B&W (although acquiring some pale green shades, suggesting
   we're moving in the right direction).
   After tests with somewhat random changes, it was found that removing
   `CX25840_SVIDEO_ON` from the vmux configuration in cx231xx-cards.c
   results in a captured stream with the expected colors.

Signed-off-by: Fabio Luongo <[e-mail]>
---
 drivers/media/usb/cx231xx/cx231xx-avcore.c | 2 +-
 drivers/media/usb/cx231xx/cx231xx-cards.c  | 3 +--
 drivers/media/usb/cx231xx/cx231xx.h        | 2 +-
 3 files changed, 3 insertions(+), 4 deletions(-)

Patch

diff --git a/drivers/media/usb/cx231xx/cx231xx-avcore.c b/drivers/media/usb/cx231xx/cx231xx-avcore.c
index 3d3c881c8e58..9025693bc295 100644
--- a/drivers/media/usb/cx231xx/cx231xx-avcore.c
+++ b/drivers/media/usb/cx231xx/cx231xx-avcore.c
@@ -623,7 +623,7 @@  int cx231xx_set_video_input_mux(struct cx231xx *dev, u8 input)
 }
 
 int cx231xx_set_decoder_video_input(struct cx231xx *dev,
-				u8 pin_type, u8 input)
+				u8 pin_type, u32 input)
 {
 	int status = 0;
 	u32 value = 0;
diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
index 92efe6c1f47b..f68a6ab9d5aa 100644
--- a/drivers/media/usb/cx231xx/cx231xx-cards.c
+++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
@@ -679,8 +679,7 @@  struct cx231xx_board cx231xx_boards[] = {
 			}, {
 				.type = CX231XX_VMUX_SVIDEO,
 				.vmux = CX231XX_VIN_1_1 |
-					(CX231XX_VIN_1_2 << 8) |
-					CX25840_SVIDEO_ON,
+					(CX231XX_VIN_3_2 << 8),
 				.amux = CX231XX_AMUX_LINE_IN,
 				.gpio = NULL,
 			}
diff --git a/drivers/media/usb/cx231xx/cx231xx.h b/drivers/media/usb/cx231xx/cx231xx.h
index 74339a6a2f71..228ecea4cfe4 100644
--- a/drivers/media/usb/cx231xx/cx231xx.h
+++ b/drivers/media/usb/cx231xx/cx231xx.h
@@ -916,7 +916,7 @@  int cx231xx_enable_i2c_port_3(struct cx231xx *dev, bool is_port_3);
 /* video audio decoder related functions */
 void video_mux(struct cx231xx *dev, int index);
 int cx231xx_set_video_input_mux(struct cx231xx *dev, u8 input);
-int cx231xx_set_decoder_video_input(struct cx231xx *dev, u8 pin_type, u8 input);
+int cx231xx_set_decoder_video_input(struct cx231xx *dev, u8 pin_type, u32 input);
 int cx231xx_do_mode_ctrl_overrides(struct cx231xx *dev);
 int cx231xx_set_audio_input(struct cx231xx *dev, u8 input);