Re: [PATCH v3 1/2] v4l2: Add the polarity flags for parallel camera bus FIELD signal
Hi Laurent, On 09/21/2011 01:12 AM, Laurent Pinchart wrote: Hi Sylwester, Thanks for the patch. On Monday 19 September 2011 19:07:55 Sylwester Nawrocki wrote: FIELD is an Even/Odd field selection signal, as specified in ITU-R BT.601 standard. Add corresponding flag for configuring the FIELD signal polarity. Also add a comment about usage of V4L2_MBUS_[HV]SYNC* flags for the hardware that uses [HV]REF signals. I like this approach better. ... +/* Field selection signal for interlaced scan mode */ +#define V4L2_MBUS_FIELD_ACTIVE_HIGH (1 10) +#define V4L2_MBUS_FIELD_ACTIVE_LOW (1 11) What does this mean ? The FIELD signal is used to select between odd and even fields. Does active high mean that the field is odd or even when the signal has a high level ? The comment should make it explicit, or we could even rename those two constants to FIELD_ODD_HIGH/FIELD_ODD_LOW (or FIELD_EVEN_HIGH/FIELD_EVEN_LOW). Yes, certainly I didn't think enough about this. I silently assumed that for V4L2_MBUS_FIELD_ACTIVE_HIGH FIELD = 0 selects Field1 (odd) and FIELD = 1 selects Field2 (even). I think it would be good to construct the macro so it is possibly self-explanatory, rather than requiring often to dig in the documentation. So I would go for V4L2_MBUS_FIELD_ODD_LOW/V4L2_MBUS_FIELD_ODD_HIGH. Unless someone proposes something different/better I'll send an amended version tomorrow. Thanks, -- Sylwester Nawrocki Samsung Poland RD Center -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v3 1/2] v4l2: Add the polarity flags for parallel camera bus FIELD signal
On 09/21/2011 03:24 PM, Sylwester Nawrocki wrote: Hi Laurent, On 09/21/2011 01:12 AM, Laurent Pinchart wrote: Hi Sylwester, Thanks for the patch. On Monday 19 September 2011 19:07:55 Sylwester Nawrocki wrote: FIELD is an Even/Odd field selection signal, as specified in ITU-R BT.601 standard. Add corresponding flag for configuring the FIELD signal polarity. Also add a comment about usage of V4L2_MBUS_[HV]SYNC* flags for the hardware that uses [HV]REF signals. I like this approach better. ... +/* Field selection signal for interlaced scan mode */ +#define V4L2_MBUS_FIELD_ACTIVE_HIGH(1 10) +#define V4L2_MBUS_FIELD_ACTIVE_LOW (1 11) What does this mean ? The FIELD signal is used to select between odd and even fields. Does active high mean that the field is odd or even when the signal has a high level ? The comment should make it explicit, or we could even rename those two constants to FIELD_ODD_HIGH/FIELD_ODD_LOW (or FIELD_EVEN_HIGH/FIELD_EVEN_LOW). Yes, certainly I didn't think enough about this. I silently assumed that for V4L2_MBUS_FIELD_ACTIVE_HIGH FIELD = 0 selects Field1 (odd) and FIELD = 1 selects Field2 (even). I think it would be good to construct the macro so it is possibly self-explanatory, rather than requiring often to dig in the documentation. So I would go for V4L2_MBUS_FIELD_ODD_LOW/V4L2_MBUS_FIELD_ODD_HIGH. Unless someone proposes something different/better I'll send an amended version tomorrow. Thinking some more of it, V4L2_MBUS_FIELD_EVEN_HIGH/V4L2_MBUS_FIELD_EVEN_LOW is perhaps more in line with other defines where *HIGH means standard, non-inverted case. So it seems better to me. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v3 1/2] v4l2: Add the polarity flags for parallel camera bus FIELD signal
Hi Sylwester, Thanks for the patch. On Monday 19 September 2011 19:07:55 Sylwester Nawrocki wrote: FIELD is an Even/Odd field selection signal, as specified in ITU-R BT.601 standard. Add corresponding flag for configuring the FIELD signal polarity. Also add a comment about usage of V4L2_MBUS_[HV]SYNC* flags for the hardware that uses [HV]REF signals. I like this approach better. Signed-off-by: Sylwester Nawrocki s.nawro...@samsung.com Signed-off-by: Kyungmin Park kyungmin.p...@samsung.com --- Resending with proper bit assignment. --- include/media/v4l2-mediabus.h | 11 +-- 1 files changed, 9 insertions(+), 2 deletions(-) diff --git a/include/media/v4l2-mediabus.h b/include/media/v4l2-mediabus.h index 6114007..f3a61ab 100644 --- a/include/media/v4l2-mediabus.h +++ b/include/media/v4l2-mediabus.h @@ -22,8 +22,12 @@ */ #define V4L2_MBUS_MASTER (1 0) #define V4L2_MBUS_SLAVE (1 1) -/* Which signal polarities it supports */ -/* Note: in BT.656 mode HSYNC and VSYNC are unused */ +/* + * Signal polarity flags + * Note: in BT.656 mode HSYNC, FIELD, and VSYNC are unused + * V4L2_MBUS_[HV]SYNC_* flags should be also used for specifying + * configuration of hardware that uses [HV]REF signals + */ #define V4L2_MBUS_HSYNC_ACTIVE_HIGH (1 2) #define V4L2_MBUS_HSYNC_ACTIVE_LOW (1 3) #define V4L2_MBUS_VSYNC_ACTIVE_HIGH (1 4) @@ -32,6 +36,9 @@ #define V4L2_MBUS_PCLK_SAMPLE_FALLING(1 7) #define V4L2_MBUS_DATA_ACTIVE_HIGH (1 8) #define V4L2_MBUS_DATA_ACTIVE_LOW(1 9) +/* Field selection signal for interlaced scan mode */ +#define V4L2_MBUS_FIELD_ACTIVE_HIGH (1 10) +#define V4L2_MBUS_FIELD_ACTIVE_LOW (1 11) What does this mean ? The FIELD signal is used to select between odd and even fields. Does active high mean that the field is odd or even when the signal has a high level ? The comment should make it explicit, or we could even rename those two constants to FIELD_ODD_HIGH/FIELD_ODD_LOW (or FIELD_EVEN_HIGH/FIELD_EVEN_LOW). /* Serial flags */ /* How many lanes the client can use */ -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
