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Message-ID: <b162ab02-550c-4b35-878c-e7f4163b676d@gpxsee.org>
Date: Thu, 30 May 2024 16:45:39 +0200
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Subject: Re: [PATCH v5 2/4] media: mgb4: Add support for V4L2_CAP_TIMEPERFRAME
To: Hans Verkuil <hverkuil@xs4all.nl>,
 Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
 =?UTF-8?Q?Martin_T=C5=AFma?= <martin.tuma@digiteqautomotive.com>
References: <20240426141619.8866-1-tumic@gpxsee.org>
 <20240426141619.8866-3-tumic@gpxsee.org>
 <93c26479-9cb4-45c2-9408-91412d1eaadd@xs4all.nl>
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From: =?UTF-8?Q?Martin_T=C5=AFma?= <tumic@gpxsee.org>
In-Reply-To: <93c26479-9cb4-45c2-9408-91412d1eaadd@xs4all.nl>
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Hi Hans,

On 30. 05. 24 2:12 odp., Hans Verkuil wrote:
> Hi Martin,
> 
> On 26/04/2024 16:16, tumic@gpxsee.org wrote:
>> From: Martin Tůma <martin.tuma@digiteqautomotive.com>
>>
>> Recent mgb4 firmwares have support for setting a variable framerate independent
>> of the signal framerate. Add/fix (the mgb4 driver already did promote
>> V4L2_CAP_TIMEPERFRAME, but it didn't work) support for V4L2_CAP_TIMEPERFRAME to
>> the driver to enable this feature.
>>
>> Additionally add support for the DV timings API (VIDIOC_G_DV_TIMINGS,
>> VIDIOC_ENUM_DV_TIMINGS, ...) for the outputs that was missing. The timings info
>> is required/used for implementing the V4L2_CAP_TIMEPERFRAME functionality.
>>
>> Signed-off-by: Martin Tůma <martin.tuma@digiteqautomotive.com>
>> ---
>>   drivers/media/pci/mgb4/mgb4_core.c      |   2 +-
>>   drivers/media/pci/mgb4/mgb4_core.h      |   2 +
>>   drivers/media/pci/mgb4/mgb4_io.h        |  24 ++-
>>   drivers/media/pci/mgb4/mgb4_sysfs_out.c |   4 +-
>>   drivers/media/pci/mgb4/mgb4_vin.c       |  86 ++++++++---
>>   drivers/media/pci/mgb4/mgb4_vin.h       |   3 +-
>>   drivers/media/pci/mgb4/mgb4_vout.c      | 190 +++++++++++++++++++++++-
>>   drivers/media/pci/mgb4/mgb4_vout.h      |   3 +-
>>   8 files changed, 278 insertions(+), 36 deletions(-)
>>
>> diff --git a/drivers/media/pci/mgb4/mgb4_core.c b/drivers/media/pci/mgb4/mgb4_core.c
>> index 9bcf10a77fd3..e028d5ce789b 100644
>> --- a/drivers/media/pci/mgb4/mgb4_core.c
>> +++ b/drivers/media/pci/mgb4/mgb4_core.c
>> @@ -302,7 +302,7 @@ static int init_i2c(struct mgb4_dev *mgbdev)
>>   	/* create dummy clock required by the xiic-i2c adapter */
>>   	snprintf(clk_name, sizeof(clk_name), "xiic-i2c.%d", id);
>>   	mgbdev->i2c_clk = clk_hw_register_fixed_rate(NULL, clk_name, NULL,
>> -						     0, 125000000);
>> +						     0, MGB4_HW_FREQ);
>>   	if (IS_ERR(mgbdev->i2c_clk)) {
>>   		dev_err(dev, "failed to register I2C clock\n");
>>   		return PTR_ERR(mgbdev->i2c_clk);
>> diff --git a/drivers/media/pci/mgb4/mgb4_core.h b/drivers/media/pci/mgb4/mgb4_core.h
>> index 2a946e46aec1..b52cd67270b5 100644
>> --- a/drivers/media/pci/mgb4/mgb4_core.h
>> +++ b/drivers/media/pci/mgb4/mgb4_core.h
>> @@ -13,6 +13,8 @@
>>   #include <linux/dmaengine.h>
>>   #include "mgb4_regs.h"
>>   
>> +#define MGB4_HW_FREQ 125000000
>> +
>>   #define MGB4_VIN_DEVICES  2
>>   #define MGB4_VOUT_DEVICES 2
>>   
>> diff --git a/drivers/media/pci/mgb4/mgb4_io.h b/drivers/media/pci/mgb4/mgb4_io.h
>> index 204613a6685c..dd8696d7df31 100644
>> --- a/drivers/media/pci/mgb4/mgb4_io.h
>> +++ b/drivers/media/pci/mgb4/mgb4_io.h
>> @@ -7,11 +7,9 @@
>>   #ifndef __MGB4_IO_H__
>>   #define __MGB4_IO_H__
>>   
>> +#include <linux/math64.h>
>>   #include <media/v4l2-dev.h>
>> -
>> -#define MGB4_DEFAULT_WIDTH     1280
>> -#define MGB4_DEFAULT_HEIGHT    640
>> -#define MGB4_DEFAULT_PERIOD    (125000000 / 60)
>> +#include "mgb4_core.h"
>>   
>>   /* Register access error indication */
>>   #define MGB4_ERR_NO_REG        0xFFFFFFFE
>> @@ -20,6 +18,9 @@
>>   #define MGB4_ERR_QUEUE_EMPTY   0xFFFFFFFC
>>   #define MGB4_ERR_QUEUE_FULL    0xFFFFFFFB
>>   
>> +#define MGB4_PERIOD(numerator, denominator) \
>> +	((u32)div_u64((MGB4_HW_FREQ * (u64)(numerator)), (denominator)))
>> +
>>   struct mgb4_frame_buffer {
>>   	struct vb2_v4l2_buffer vb;
>>   	struct list_head list;
>> @@ -30,11 +31,24 @@ static inline struct mgb4_frame_buffer *to_frame_buffer(struct vb2_v4l2_buffer *
>>   	return container_of(vbuf, struct mgb4_frame_buffer, vb);
>>   }
>>   
>> -static inline bool has_yuv(struct mgb4_regs *video)
>> +static inline bool has_yuv_and_timeperframe(struct mgb4_regs *video)
>>   {
>>   	u32 status = mgb4_read_reg(video, 0xD0);
>>   
>>   	return (status & (1U << 8));
>>   }
>>   
>> +#define has_yuv(video) has_yuv_and_timeperframe(video)
>> +#define has_timeperframe(video) has_yuv_and_timeperframe(video)
>> +
>> +static inline u32 pixel_size(struct v4l2_dv_timings *timings)
>> +{
>> +	struct v4l2_bt_timings *bt = &timings->bt;
>> +
>> +	u32 height = bt->height + bt->vfrontporch + bt->vsync + bt->vbackporch;
>> +	u32 width = bt->width + bt->hfrontporch + bt->hsync + bt->hbackporch;
>> +
>> +	return width * height;
>> +}
>> +
>>   #endif
>> diff --git a/drivers/media/pci/mgb4/mgb4_sysfs_out.c b/drivers/media/pci/mgb4/mgb4_sysfs_out.c
>> index 9f6e81c57726..f67ff2a48329 100644
>> --- a/drivers/media/pci/mgb4/mgb4_sysfs_out.c
>> +++ b/drivers/media/pci/mgb4/mgb4_sysfs_out.c
>> @@ -231,7 +231,7 @@ static ssize_t frame_rate_show(struct device *dev,
>>   	u32 period = mgb4_read_reg(&voutdev->mgbdev->video,
>>   				   voutdev->config->regs.frame_period);
>>   
>> -	return sprintf(buf, "%u\n", 125000000 / period);
>> +	return sprintf(buf, "%u\n", MGB4_HW_FREQ / period);
>>   }
>>   
>>   /*
>> @@ -252,7 +252,7 @@ static ssize_t frame_rate_store(struct device *dev,
>>   		return ret;
>>   
>>   	mgb4_write_reg(&voutdev->mgbdev->video,
>> -		       voutdev->config->regs.frame_period, 125000000 / val);
>> +		       voutdev->config->regs.frame_period, MGB4_HW_FREQ / val);
>>   
>>   	return count;
>>   }
>> diff --git a/drivers/media/pci/mgb4/mgb4_vin.c b/drivers/media/pci/mgb4/mgb4_vin.c
>> index 7fb14e867e8d..422e77fec1c1 100644
>> --- a/drivers/media/pci/mgb4/mgb4_vin.c
>> +++ b/drivers/media/pci/mgb4/mgb4_vin.c
>> @@ -34,8 +34,8 @@ ATTRIBUTE_GROUPS(mgb4_fpdl3_in);
>>   ATTRIBUTE_GROUPS(mgb4_gmsl_in);
>>   
>>   static const struct mgb4_vin_config vin_cfg[] = {
>> -	{0, 0, 0, 6, {0x10, 0x00, 0x04, 0x08, 0x1C, 0x14, 0x18, 0x20, 0x24, 0x28}},
>> -	{1, 1, 1, 7, {0x40, 0x30, 0x34, 0x38, 0x4C, 0x44, 0x48, 0x50, 0x54, 0x58}}
>> +	{0, 0, 0, 6, {0x10, 0x00, 0x04, 0x08, 0x1C, 0x14, 0x18, 0x20, 0x24, 0x28, 0xE8}},
>> +	{1, 1, 1, 7, {0x40, 0x30, 0x34, 0x38, 0x4C, 0x44, 0x48, 0x50, 0x54, 0x58, 0xEC}}
>>   };
>>   
>>   static const struct i2c_board_info fpdl3_deser_info[] = {
>> @@ -384,6 +384,7 @@ static int vidioc_enum_frameintervals(struct file *file, void *priv,
>>   {
>>   	struct mgb4_vin_dev *vindev = video_drvdata(file);
>>   	struct mgb4_regs *video = &vindev->mgbdev->video;
>> +	struct v4l2_dv_timings timings;
>>   
>>   	if (ival->index != 0)
>>   		return -EINVAL;
>> @@ -394,12 +395,15 @@ static int vidioc_enum_frameintervals(struct file *file, void *priv,
>>   	    ival->height != vindev->timings.bt.height)
>>   		return -EINVAL;
>>   
>> -	ival->type = V4L2_FRMIVAL_TYPE_CONTINUOUS;
>> -	ival->stepwise.min.denominator = 60;
>> -	ival->stepwise.min.numerator = 1;
>> -	ival->stepwise.max.denominator = 1;
>> -	ival->stepwise.max.numerator = 1;
>> -	ival->stepwise.step = ival->stepwise.max;
>> +	get_timings(vindev, &timings);
> 
> Hmm, if get_timings returns an error (no link or lock), then the
> code below will return garbage (timings is uninitialized).
> 
> Shouldn't this just use vindev->timings instead?
> 

You are right. Using vindev->timings here makes much more sense. It may 
not be the actual values "on the wire", but it is something the user set 
when there was a valid signal or the initial value (which is also not 
properly initialized, when there is no signal during open as you found 
out ;-), see below). I will fix it (in all the following cases as well).

>> +
>> +	ival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
>> +	ival->stepwise.max.denominator = MGB4_HW_FREQ;
>> +	ival->stepwise.max.numerator = 0xFFFFFFFF;
>> +	ival->stepwise.min.denominator = timings.bt.pixelclock;
>> +	ival->stepwise.min.numerator = pixel_size(&timings);
>> +	ival->stepwise.step.denominator = MGB4_HW_FREQ;
>> +	ival->stepwise.step.numerator = 1;
>>   
>>   	return 0;
>>   }
>> @@ -558,24 +562,60 @@ static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
>>   	return 0;
>>   }
>>   
>> -static int vidioc_parm(struct file *file, void *priv,
>> -		       struct v4l2_streamparm *parm)
>> +static int vidioc_g_parm(struct file *file, void *priv,
>> +			 struct v4l2_streamparm *parm)
>>   {
>>   	struct mgb4_vin_dev *vindev = video_drvdata(file);
>>   	struct mgb4_regs *video = &vindev->mgbdev->video;
>> -	const struct mgb4_vin_regs *regs = &vindev->config->regs;
>> -	struct v4l2_fract timeperframe = {
>> -		.numerator = mgb4_read_reg(video, regs->frame_period),
>> -		.denominator = 125000000,
>> -	};
>> +	struct v4l2_fract *tpf = &parm->parm.output.timeperframe;
>> +	struct v4l2_dv_timings timings;
>> +	u32 timer;
>>   
>>   	parm->parm.capture.readbuffers = 2;
>> -	parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>> -	parm->parm.capture.timeperframe = timeperframe;
>> +
>> +	if (has_timeperframe(video)) {
>> +		timer = mgb4_read_reg(video, vindev->config->regs.timer);
>> +		if (timer < 0xFFFF) {
>> +			get_timings(vindev, &timings);
> 
> Ditto.
> 
>> +			tpf->numerator = pixel_size(&timings);
>> +			tpf->denominator = timings.bt.pixelclock;
>> +		} else {
>> +			tpf->numerator = timer;
>> +			tpf->denominator = MGB4_HW_FREQ;
>> +		}
>> +
>> +		parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
>> +	}
>>   
>>   	return 0;
>>   }
>>   
>> +static int vidioc_s_parm(struct file *file, void *priv,
>> +			 struct v4l2_streamparm *parm)
>> +{
>> +	struct mgb4_vin_dev *vindev = video_drvdata(file);
>> +	struct mgb4_regs *video = &vindev->mgbdev->video;
>> +	struct v4l2_fract *tpf = &parm->parm.output.timeperframe;
>> +	struct v4l2_dv_timings timings;
>> +	u32 period, timer;
>> +
>> +	if (has_timeperframe(video)) {
>> +		timer = tpf->denominator ?
>> +			MGB4_PERIOD(tpf->numerator, tpf->denominator) : 0;
>> +		if (timer) {
>> +			get_timings(vindev, &timings);
> 
> Ditto.
> 
>> +			period = MGB4_PERIOD(pixel_size(&timings),
>> +					     timings.bt.pixelclock);
>> +			if (timer < period)
>> +				timer = 0;
>> +		}
>> +
>> +		mgb4_write_reg(video, vindev->config->regs.timer, timer);
>> +	}
>> +
>> +	return vidioc_g_parm(file, priv, parm);
>> +}
> 
> I noticed that fh_open also calls get_timings without checking the error
> code. It is OK that fh_open calls it (on first open), but if it returns an
> error, then vindev->timings must be set to some timings (for example:
> V4L2_DV_BT_CEA_1920X1080P60).
> 
> Without that, VIDIOC_G_DV_TIMINGS can return invalid timings. It must
> return something valid, even if it doesn't match what is seen on the actual
> video link.
> 

Ok. I will fix the initialization and set it to something valid when 
there is no signal at the moment of open/initialization.

>> +
>>   static int vidioc_s_dv_timings(struct file *file, void *fh,
>>   			       struct v4l2_dv_timings *timings)
>>   {
>> @@ -659,8 +699,8 @@ static const struct v4l2_ioctl_ops video_ioctl_ops = {
>>   	.vidioc_expbuf = vb2_ioctl_expbuf,
>>   	.vidioc_streamon = vb2_ioctl_streamon,
>>   	.vidioc_streamoff = vb2_ioctl_streamoff,
>> -	.vidioc_g_parm = vidioc_parm,
>> -	.vidioc_s_parm = vidioc_parm,
>> +	.vidioc_g_parm = vidioc_g_parm,
>> +	.vidioc_s_parm = vidioc_s_parm,
>>   	.vidioc_dv_timings_cap = vidioc_dv_timings_cap,
>>   	.vidioc_enum_dv_timings = vidioc_enum_dv_timings,
>>   	.vidioc_g_dv_timings = vidioc_g_dv_timings,
>> @@ -843,10 +883,16 @@ static void debugfs_init(struct mgb4_vin_dev *vindev)
>>   	vindev->regs[7].offset = vindev->config->regs.signal2;
>>   	vindev->regs[8].name = "PADDING_PIXELS";
>>   	vindev->regs[8].offset = vindev->config->regs.padding;
>> +	if (has_timeperframe(video)) {
>> +		vindev->regs[9].name = "TIMER";
>> +		vindev->regs[9].offset = vindev->config->regs.timer;
>> +		vindev->regset.nregs = 10;
>> +	} else {
>> +		vindev->regset.nregs = 9;
>> +	}
>>   
>>   	vindev->regset.base = video->membase;
>>   	vindev->regset.regs = vindev->regs;
>> -	vindev->regset.nregs = ARRAY_SIZE(vindev->regs);
>>   
>>   	debugfs_create_regset32("registers", 0444, vindev->debugfs,
>>   				&vindev->regset);
>> diff --git a/drivers/media/pci/mgb4/mgb4_vin.h b/drivers/media/pci/mgb4/mgb4_vin.h
>> index 0249b400ad4d..9693bd0ce180 100644
>> --- a/drivers/media/pci/mgb4/mgb4_vin.h
>> +++ b/drivers/media/pci/mgb4/mgb4_vin.h
>> @@ -25,6 +25,7 @@ struct mgb4_vin_regs {
>>   	u32 signal;
>>   	u32 signal2;
>>   	u32 padding;
>> +	u32 timer;
>>   };
>>   
>>   struct mgb4_vin_config {
>> @@ -59,7 +60,7 @@ struct mgb4_vin_dev {
>>   #ifdef CONFIG_DEBUG_FS
>>   	struct dentry *debugfs;
>>   	struct debugfs_regset32 regset;
>> -	struct debugfs_reg32 regs[9];
>> +	struct debugfs_reg32 regs[sizeof(struct mgb4_vin_regs) / 4];
>>   #endif
>>   };
>>   
>> diff --git a/drivers/media/pci/mgb4/mgb4_vout.c b/drivers/media/pci/mgb4/mgb4_vout.c
>> index 2ee9606d9072..d98b6e87d71f 100644
>> --- a/drivers/media/pci/mgb4/mgb4_vout.c
>> +++ b/drivers/media/pci/mgb4/mgb4_vout.c
>> @@ -16,6 +16,7 @@
>>   #include <media/v4l2-ioctl.h>
>>   #include <media/videobuf2-v4l2.h>
>>   #include <media/videobuf2-dma-sg.h>
>> +#include <media/v4l2-dv-timings.h>
>>   #include "mgb4_core.h"
>>   #include "mgb4_dma.h"
>>   #include "mgb4_sysfs.h"
>> @@ -23,12 +24,16 @@
>>   #include "mgb4_cmt.h"
>>   #include "mgb4_vout.h"
>>   
>> +#define DEFAULT_WIDTH     1280
>> +#define DEFAULT_HEIGHT    640
>> +#define DEFAULT_PERIOD    (MGB4_HW_FREQ / 60)
>> +
>>   ATTRIBUTE_GROUPS(mgb4_fpdl3_out);
>>   ATTRIBUTE_GROUPS(mgb4_gmsl_out);
>>   
>>   static const struct mgb4_vout_config vout_cfg[] = {
>> -	{0, 0, 8, {0x78, 0x60, 0x64, 0x68, 0x74, 0x6C, 0x70, 0x7c}},
>> -	{1, 1, 9, {0x98, 0x80, 0x84, 0x88, 0x94, 0x8c, 0x90, 0x9c}}
>> +	{0, 0, 8, {0x78, 0x60, 0x64, 0x68, 0x74, 0x6C, 0x70, 0x7C, 0xE0}},
>> +	{1, 1, 9, {0x98, 0x80, 0x84, 0x88, 0x94, 0x8C, 0x90, 0x9C, 0xE4}}
>>   };
>>   
>>   static const struct i2c_board_info fpdl3_ser_info[] = {
>> @@ -40,6 +45,49 @@ static const struct mgb4_i2c_kv fpdl3_i2c[] = {
>>   	{0x05, 0xFF, 0x04}, {0x06, 0xFF, 0x01}, {0xC2, 0xFF, 0x80}
>>   };
>>   
>> +static const struct v4l2_dv_timings_cap video_timings_cap = {
>> +	.type = V4L2_DV_BT_656_1120,
>> +	.bt = {
>> +		.min_width = 320,
>> +		.max_width = 4096,
>> +		.min_height = 240,
>> +		.max_height = 2160,
>> +		.min_pixelclock = 1843200, /* 320 x 240 x 24Hz */
>> +		.max_pixelclock = 530841600, /* 4096 x 2160 x 60Hz */
>> +		.standards = V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_DMT |
>> +			V4L2_DV_BT_STD_CVT | V4L2_DV_BT_STD_GTF,
>> +		.capabilities = V4L2_DV_BT_CAP_PROGRESSIVE |
>> +			V4L2_DV_BT_CAP_CUSTOM,
>> +	},
>> +};
>> +
>> +static void get_timings(struct mgb4_vout_dev *voutdev,
>> +			struct v4l2_dv_timings *timings)
>> +{
>> +	struct mgb4_regs *video = &voutdev->mgbdev->video;
>> +	const struct mgb4_vout_regs *regs = &voutdev->config->regs;
>> +
>> +	u32 hsync = mgb4_read_reg(video, regs->hsync);
>> +	u32 vsync = mgb4_read_reg(video, regs->vsync);
>> +	u32 resolution = mgb4_read_reg(video, regs->resolution);
>> +
>> +	memset(timings, 0, sizeof(*timings));
>> +	timings->type = V4L2_DV_BT_656_1120;
>> +	timings->bt.width = resolution >> 16;
>> +	timings->bt.height = resolution & 0xFFFF;
>> +	if (hsync & (1U << 31))
>> +		timings->bt.polarities |= V4L2_DV_HSYNC_POS_POL;
>> +	if (vsync & (1U << 31))
>> +		timings->bt.polarities |= V4L2_DV_VSYNC_POS_POL;
>> +	timings->bt.pixelclock = voutdev->freq * 1000;
>> +	timings->bt.hsync = (hsync & 0x00FF0000) >> 16;
>> +	timings->bt.vsync = (vsync & 0x00FF0000) >> 16;
>> +	timings->bt.hbackporch = (hsync & 0x0000FF00) >> 8;
>> +	timings->bt.hfrontporch = hsync & 0x000000FF;
>> +	timings->bt.vbackporch = (vsync & 0x0000FF00) >> 8;
>> +	timings->bt.vfrontporch = vsync & 0x000000FF;
>> +}
>> +
>>   static void return_all_buffers(struct mgb4_vout_dev *voutdev,
>>   			       enum vb2_buffer_state state)
>>   {
>> @@ -336,11 +384,128 @@ static int vidioc_enum_output(struct file *file, void *priv,
>>   		return -EINVAL;
>>   
>>   	out->type = V4L2_OUTPUT_TYPE_ANALOG;
>> +	out->capabilities = V4L2_OUT_CAP_DV_TIMINGS;
>>   	strscpy(out->name, "MGB4", sizeof(out->name));
>>   
>>   	return 0;
>>   }
>>   
>> +static int vidioc_enum_frameintervals(struct file *file, void *priv,
>> +				      struct v4l2_frmivalenum *ival)
>> +{
>> +	struct mgb4_vout_dev *voutdev = video_drvdata(file);
>> +	struct mgb4_regs *video = &voutdev->mgbdev->video;
>> +	struct v4l2_dv_timings timings;
>> +
>> +	if (ival->index != 0)
>> +		return -EINVAL;
>> +	if (!(ival->pixel_format == V4L2_PIX_FMT_ABGR32 ||
>> +	      ((has_yuv(video) && ival->pixel_format == V4L2_PIX_FMT_YUYV))))
>> +		return -EINVAL;
>> +	if (ival->width != voutdev->width || ival->height != voutdev->height)
>> +		return -EINVAL;
>> +
>> +	get_timings(voutdev, &timings);
>> +
>> +	ival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
>> +	ival->stepwise.max.denominator = MGB4_HW_FREQ;
>> +	ival->stepwise.max.numerator = 0xFFFFFFFF;
>> +	ival->stepwise.min.denominator = timings.bt.pixelclock;
>> +	ival->stepwise.min.numerator = pixel_size(&timings);
>> +	ival->stepwise.step.denominator = MGB4_HW_FREQ;
>> +	ival->stepwise.step.numerator = 1;
>> +
>> +	return 0;
>> +}
>> +
>> +static int vidioc_g_parm(struct file *file, void *priv,
>> +			 struct v4l2_streamparm *parm)
>> +{
>> +	struct mgb4_vout_dev *voutdev = video_drvdata(file);
>> +	struct mgb4_regs *video = &voutdev->mgbdev->video;
>> +	struct v4l2_fract *tpf = &parm->parm.output.timeperframe;
>> +	struct v4l2_dv_timings timings;
>> +	u32 timer;
>> +
>> +	parm->parm.output.writebuffers = 2;
>> +
>> +	if (has_timeperframe(video)) {
>> +		timer = mgb4_read_reg(video, voutdev->config->regs.timer);
>> +		if (timer < 0xFFFF) {
>> +			get_timings(voutdev, &timings);
>> +			tpf->numerator = pixel_size(&timings);
>> +			tpf->denominator = timings.bt.pixelclock;
>> +		} else {
>> +			tpf->numerator = timer;
>> +			tpf->denominator = MGB4_HW_FREQ;
>> +		}
>> +
>> +		parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int vidioc_s_parm(struct file *file, void *priv,
>> +			 struct v4l2_streamparm *parm)
>> +{
>> +	struct mgb4_vout_dev *voutdev = video_drvdata(file);
>> +	struct mgb4_regs *video = &voutdev->mgbdev->video;
>> +	struct v4l2_fract *tpf = &parm->parm.output.timeperframe;
>> +	struct v4l2_dv_timings timings;
>> +	u32 timer, period;
>> +
>> +	if (has_timeperframe(video)) {
>> +		timer = tpf->denominator ?
>> +			MGB4_PERIOD(tpf->numerator, tpf->denominator) : 0;
>> +		if (timer) {
>> +			get_timings(voutdev, &timings);
>> +			period = MGB4_PERIOD(pixel_size(&timings),
>> +					     timings.bt.pixelclock);
>> +			if (timer < period)
>> +				timer = 0;
>> +		}
>> +
>> +		mgb4_write_reg(video, voutdev->config->regs.timer, timer);
>> +	}
>> +
>> +	return vidioc_g_parm(file, priv, parm);
>> +}
>> +
>> +static int vidioc_g_dv_timings(struct file *file, void *fh,
>> +			       struct v4l2_dv_timings *timings)
>> +{
>> +	struct mgb4_vout_dev *voutdev = video_drvdata(file);
>> +
>> +	get_timings(voutdev, timings);
>> +
>> +	return 0;
>> +}
>> +
>> +static int vidioc_s_dv_timings(struct file *file, void *fh,
>> +			       struct v4l2_dv_timings *timings)
>> +{
>> +	struct mgb4_vout_dev *voutdev = video_drvdata(file);
>> +
>> +	get_timings(voutdev, timings);
>> +
>> +	return 0;
>> +}
>> +
>> +static int vidioc_enum_dv_timings(struct file *file, void *fh,
>> +				  struct v4l2_enum_dv_timings *timings)
>> +{
>> +	return v4l2_enum_dv_timings_cap(timings, &video_timings_cap, NULL, NULL);
>> +}
>> +
>> +static int vidioc_dv_timings_cap(struct file *file, void *fh,
>> +				 struct v4l2_dv_timings_cap *cap)
>> +{
>> +	*cap = video_timings_cap;
>> +
>> +	return 0;
>> +}
>> +
>>   static const struct v4l2_ioctl_ops video_ioctl_ops = {
>>   	.vidioc_querycap = vidioc_querycap,
>>   	.vidioc_enum_fmt_vid_out = vidioc_enum_fmt,
>> @@ -348,8 +513,15 @@ static const struct v4l2_ioctl_ops video_ioctl_ops = {
>>   	.vidioc_s_fmt_vid_out = vidioc_s_fmt,
>>   	.vidioc_g_fmt_vid_out = vidioc_g_fmt,
>>   	.vidioc_enum_output = vidioc_enum_output,
>> +	.vidioc_enum_frameintervals = vidioc_enum_frameintervals,
>>   	.vidioc_g_output = vidioc_g_output,
>>   	.vidioc_s_output = vidioc_s_output,
>> +	.vidioc_g_parm = vidioc_g_parm,
>> +	.vidioc_s_parm = vidioc_s_parm,
>> +	.vidioc_dv_timings_cap = vidioc_dv_timings_cap,
>> +	.vidioc_enum_dv_timings = vidioc_enum_dv_timings,
>> +	.vidioc_g_dv_timings = vidioc_g_dv_timings,
>> +	.vidioc_s_dv_timings = vidioc_s_dv_timings,
>>   	.vidioc_reqbufs = vb2_ioctl_reqbufs,
>>   	.vidioc_create_bufs = vb2_ioctl_create_bufs,
>>   	.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
>> @@ -492,10 +664,10 @@ static void fpga_init(struct mgb4_vout_dev *voutdev)
>>   
>>   	mgb4_write_reg(video, regs->config, 0x00000011);
>>   	mgb4_write_reg(video, regs->resolution,
>> -		       (MGB4_DEFAULT_WIDTH << 16) | MGB4_DEFAULT_HEIGHT);
>> +		       (DEFAULT_WIDTH << 16) | DEFAULT_HEIGHT);
>>   	mgb4_write_reg(video, regs->hsync, 0x00102020);
>>   	mgb4_write_reg(video, regs->vsync, 0x40020202);
>> -	mgb4_write_reg(video, regs->frame_period, MGB4_DEFAULT_PERIOD);
>> +	mgb4_write_reg(video, regs->frame_period, DEFAULT_PERIOD);
>>   	mgb4_write_reg(video, regs->padding, 0x00000000);
>>   
>>   	voutdev->freq = mgb4_cmt_set_vout_freq(voutdev, 70000 >> 1) << 1;
>> @@ -526,12 +698,18 @@ static void debugfs_init(struct mgb4_vout_dev *voutdev)
>>   	voutdev->regs[4].offset = voutdev->config->regs.vsync;
>>   	voutdev->regs[5].name = "FRAME_PERIOD";
>>   	voutdev->regs[5].offset = voutdev->config->regs.frame_period;
>> -	voutdev->regs[6].name = "PADDING";
>> +	voutdev->regs[6].name = "PADDING_PIXELS";
>>   	voutdev->regs[6].offset = voutdev->config->regs.padding;
>> +	if (has_timeperframe(video)) {
>> +		voutdev->regs[7].name = "TIMER";
>> +		voutdev->regs[7].offset = voutdev->config->regs.timer;
>> +		voutdev->regset.nregs = 8;
>> +	} else {
>> +		voutdev->regset.nregs = 7;
>> +	}
>>   
>>   	voutdev->regset.base = video->membase;
>>   	voutdev->regset.regs = voutdev->regs;
>> -	voutdev->regset.nregs = ARRAY_SIZE(voutdev->regs);
>>   
>>   	debugfs_create_regset32("registers", 0444, voutdev->debugfs,
>>   				&voutdev->regset);
>> diff --git a/drivers/media/pci/mgb4/mgb4_vout.h b/drivers/media/pci/mgb4/mgb4_vout.h
>> index b163dee711fd..ab9b58b1deb7 100644
>> --- a/drivers/media/pci/mgb4/mgb4_vout.h
>> +++ b/drivers/media/pci/mgb4/mgb4_vout.h
>> @@ -23,6 +23,7 @@ struct mgb4_vout_regs {
>>   	u32 hsync;
>>   	u32 vsync;
>>   	u32 padding;
>> +	u32 timer;
>>   };
>>   
>>   struct mgb4_vout_config {
>> @@ -55,7 +56,7 @@ struct mgb4_vout_dev {
>>   #ifdef CONFIG_DEBUG_FS
>>   	struct dentry *debugfs;
>>   	struct debugfs_regset32 regset;
>> -	struct debugfs_reg32 regs[7];
>> +	struct debugfs_reg32 regs[sizeof(struct mgb4_vout_regs) / 4];
>>   #endif
>>   };
>>   
> 
> Regards,
> 
> 	Hans
>

Finally, I would like to ask a question that I should probably know the 
answer to, but I don't. How shall I proceed when I want to send this 
series of patches again AND the patch you requested for the debugfs 
cleanup? If I send both separately based against the current 
master/media_stage master then you may have troubles merging them later. 
If I put it together, the series will become larger and will mix stuff 
that does not logically fit together.

In fact I have more such stupid questions ;-) - If I want to send the 
debugfs cleanup patch, shall I base it against the media_stage fixes 
branch (where the fix is at the moment only) or aginst the master 
branch. Or shall I wait until the fix is merged into the master branch 
and then send the patch?

Sorry for bothering you with such "newbie" questions, but I have not 
found relevant info how the workflow with the various branches and 
multiple patches is. Could you clarify it for me? Thanks

M.