Am 24.03.2013 12:44, schrieb Mauro Carvalho Chehab:
> Em Sat, 23 Mar 2013 18:27:12 +0100
> Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx> escreveu:
>
>> The Windows driver writes the output resolution to registers 0x34 (width / 16)
>> and 0x35 (height / 16) always.
>> We don't know yet what these registers are used for.
>>
>> Signed-off-by: Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx>
>> ---
>> drivers/media/usb/em28xx/em28xx-core.c | 7 +++++++
>> drivers/media/usb/em28xx/em28xx-reg.h | 6 ++++++
>> 2 Dateien geändert, 13 Zeilen hinzugefügt(+)
>>
>> diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c
>> index 7b9f76b..0ce6b0f 100644
>> --- a/drivers/media/usb/em28xx/em28xx-core.c
>> +++ b/drivers/media/usb/em28xx/em28xx-core.c
>> @@ -766,6 +766,13 @@ static void em28xx_capture_area_set(struct em28xx *dev, u8 hstart, u8 vstart,
>> em28xx_write_regs(dev, EM28XX_R1E_CWIDTH, &cwidth, 1);
>> em28xx_write_regs(dev, EM28XX_R1F_CHEIGHT, &cheight, 1);
>> em28xx_write_regs(dev, EM28XX_R1B_OFLOW, &overflow, 1);
>> +
>> + if (dev->is_em25xx) {
>> + em28xx_write_reg(dev, 0x34, width >> 4);
>> + em28xx_write_reg(dev, 0x35, height >> 4);
>> + }
>> + /* FIXME: function/meaning of these registers ? */
>> + /* FIXME: align width+height to multiples of 4 ?! */
> Please move those comments to be _before_ the code you're commenting.
>
> E. g. something like:
>
> if (dev->is_em25xx) {
> /*
> * FIXME:
> * - function/meaning of these registers are unknown;
> * - align width+height to multiples of 4 ?!
> */
> em28xx_write_reg(dev, 0x34, width >> 4);
> em28xx_write_reg(dev, 0x35, height >> 4);
> }
Ok, no problem.
Frank
>
>> }
>>
>> static int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v)
>> diff --git a/drivers/media/usb/em28xx/em28xx-reg.h b/drivers/media/usb/em28xx/em28xx-reg.h
>> index 1b0ecd6..e08982a 100644
>> --- a/drivers/media/usb/em28xx/em28xx-reg.h
>> +++ b/drivers/media/usb/em28xx/em28xx-reg.h
>> @@ -167,6 +167,12 @@
>>
>> #define EM28XX_R34_VBI_START_H 0x34
>> #define EM28XX_R35_VBI_START_V 0x35
>> +/* NOTE: the EM276x (and EM25xx, EM277x/8x ?) (camera bridges) use these
>> + * registers for a different unknown purpose.
>> + * => register 0x34 is set to capture width / 16
>> + * => register 0x35 is set to capture height / 16
>> + */
>> +
>> #define EM28XX_R36_VBI_WIDTH 0x36
>> #define EM28XX_R37_VBI_HEIGHT 0x37
>>
>
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