From 48bb7315f8205272c69fa49c732adb20b2f08614 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 27 Apr 2012 13:00:57 -0300 Subject: [PATCH] [media] gspca_pac7302: Document some more registers Note like all info on the pac73xx chips, this info was found by trial and error, so it is not necessarily 100% correct. Signed-off-by: Hans de Goede Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/gspca/pac7302.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/media/video/gspca/pac7302.c b/drivers/media/video/gspca/pac7302.c index 1e88d3a574d9..a2a42f61d3c0 100644 --- a/drivers/media/video/gspca/pac7302.c +++ b/drivers/media/video/gspca/pac7302.c @@ -30,6 +30,14 @@ * * Address Description * 0x78 Global control, bit 6 controls the LED (inverted) + * 0x80 Compression balance, 2 interesting settings: + * 0x0f Default + * 0x50 Values >= this switch the camera to a lower compression, + * using the same table for both luminance and chrominance. + * This gives a sharper picture. Only usable when running + * at < 15 fps! Note currently the driver does not use this + * as the quality gain is small and the generated JPG-s are + * only understood by v4l-utils >= 0.8.9 * * Register page 3: * @@ -43,8 +51,14 @@ * 1 -> ~30 fps, 2 -> ~20 fps * 0x0e Exposure bits 0-7, 0-448, 0 = use full frame time * 0x0f Exposure bit 8, 0-448, 448 = no exposure at all - * 0x10 Master gain 0-31 + * 0x10 Gain 0-31 + * 0x12 Another gain 0-31, unlike 0x10 this one seems to start with an + * amplification value of 1 rather then 0 at its lowest setting * 0x21 Bitfield: 0-1 unused, 2-3 vflip/hflip, 4-5 unknown, 6-7 unused + * 0x80 Another framerate control, best left at 1, moving it from 1 to + * 2 causes the framerate to become 3/4th of what it was, and + * also seems to cause pixel averaging, resulting in an effective + * resolution of 320x240 and thus a much blockier image * * The registers are accessed in the following functions: * -- 2.30.2