Re: [PATCH v3 2/2] media: vimc: Add a control to display info on test image

[Dafna Hirschfeld <dafna.hirschfeld@collabora.com>]

Hi, thanks for the patch

On 18.06.20 21:05, Kaaira Gupta wrote:
> Add a control in VIMC to display information such as the correct oder of
> colors for a given test pattern, brightness, hue, saturation, contrast
> and, width and height at sensor over test image; and display that
> information.
> 
> Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in>
> ---
>   drivers/media/test-drivers/vimc/Kconfig       |  2 +
>   drivers/media/test-drivers/vimc/vimc-common.h |  1 +
>   drivers/media/test-drivers/vimc/vimc-sensor.c | 47 ++++++++++++++++++-
>   3 files changed, 49 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/test-drivers/vimc/Kconfig b/drivers/media/test-drivers/vimc/Kconfig
> index 4068a67585f9..da4b2ad6e40c 100644
> --- a/drivers/media/test-drivers/vimc/Kconfig
> +++ b/drivers/media/test-drivers/vimc/Kconfig
> @@ -2,6 +2,8 @@
>   config VIDEO_VIMC
>   	tristate "Virtual Media Controller Driver (VIMC)"
>   	depends on VIDEO_DEV && VIDEO_V4L2
> +	select FONT_SUPPORT
> +	select FONT_8x16
>   	select MEDIA_CONTROLLER
>   	select VIDEO_V4L2_SUBDEV_API
>   	select VIDEOBUF2_VMALLOC
> diff --git a/drivers/media/test-drivers/vimc/vimc-common.h b/drivers/media/test-drivers/vimc/vimc-common.h
> index ae163dec2459..afda52253402 100644
> --- a/drivers/media/test-drivers/vimc/vimc-common.h
> +++ b/drivers/media/test-drivers/vimc/vimc-common.h
> @@ -20,6 +20,7 @@
>   #define VIMC_CID_VIMC_CLASS		(0x00f00000 | 1)
>   #define VIMC_CID_TEST_PATTERN		(VIMC_CID_VIMC_BASE + 0)
>   #define VIMC_CID_MEAN_WIN_SIZE		(VIMC_CID_VIMC_BASE + 1)
> +#define VIMC_CID_SHOW_INFO		(VIMC_CID_VIMC_BASE + 2)
>   
>   #define VIMC_FRAME_MAX_WIDTH 4096
>   #define VIMC_FRAME_MAX_HEIGHT 2160
> diff --git a/drivers/media/test-drivers/vimc/vimc-sensor.c b/drivers/media/test-drivers/vimc/vimc-sensor.c
> index a2f09ac9a360..f5352b115aac 100644
> --- a/drivers/media/test-drivers/vimc/vimc-sensor.c
> +++ b/drivers/media/test-drivers/vimc/vimc-sensor.c
> @@ -5,6 +5,7 @@
>    * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
>    */
>   
> +#include <linux/font.h>
>   #include <linux/v4l2-mediabus.h>
>   #include <linux/vmalloc.h>
>   #include <media/v4l2-ctrls.h>
> @@ -19,6 +20,7 @@ struct vimc_sen_device {
>   	struct v4l2_subdev sd;
>   	struct tpg_data tpg;
>   	u8 *frame;
> +	bool show_info;

I see that vivid saves the 'v4l2_ctrl*' of the controls,
maybe you should also do that instead of saving a boolean,

>   	/* The active format */
>   	struct v4l2_mbus_framefmt mbus_format;
>   	struct v4l2_ctrl_handler hdl;
> @@ -185,10 +187,29 @@ static const struct v4l2_subdev_pad_ops vimc_sen_pad_ops = {
>   static void *vimc_sen_process_frame(struct vimc_ent_device *ved,
>   				    const void *sink_frame)
>   {
> +	u8 *basep[TPG_MAX_PLANES][2];
> +	char *order;
> +	char str[100];
> +	int line = 1;

Those vars declarations can be inside the 'if (vsen->show_info)'

>   	struct vimc_sen_device *vsen = container_of(ved, struct vimc_sen_device,
>   						    ved);
> -
>   	tpg_fill_plane_buffer(&vsen->tpg, 0, 0, vsen->frame);
> +	if (vsen->show_info) {
> +		tpg_calc_text_basep(&vsen->tpg, basep, 0, vsen->frame);
> +		order = tpg_g_color_order(&vsen->tpg);
> +		tpg_gen_text(&vsen->tpg, basep, line++ * 16, 16, order);
> +		snprintf(str, sizeof(str), " brightness %3d, contrast %3d, saturation %3d, hue %d ",
> +			 vsen->tpg.brightness,
> +			 vsen->tpg.contrast,
> +			 vsen->tpg.saturation,
> +			 vsen->tpg.hue);
> +		tpg_gen_text(&vsen->tpg, basep, line++ * 16, 16, str);
> +
> +		snprintf(str, sizeof(str), " sensor size: %dx%d",
> +			 vsen->mbus_format.width, vsen->mbus_format.height);
> +		tpg_gen_text(&vsen->tpg, basep, line++ * 16, 16, str);
> +	}
> +
>   	return vsen->frame;
>   }
>   
> @@ -200,6 +221,14 @@ static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable)
>   	if (enable) {
>   		const struct vimc_pix_map *vpix;
>   		unsigned int frame_size;
> +		const struct font_desc *font = find_font("VGA8x16");
> +
> +		if (font == NULL) {
Using 'if (!font)' is the way to check null pointer, instead of compering to null. Running checkpatch.pl with '--strict'
will catch that.
> +			pr_err("vimc: could not find font\n");
'dev_err' should be used instead of 'pr_err'.

Also, maybe checking the font here is a bit late, since the user already
wants to stream and expect the info to be shown.
Maybe it is better to check the font on 'vimc_sen_s_ctrl'.

Thanks,
Dafna

> +			vsen->show_info = 0;
> +		} else {
> +			tpg_set_font(font->data);
> +		}
>   
>   		/* Calculate the frame size */
>   		vpix = vimc_pix_map_by_code(vsen->mbus_format.code);
> @@ -269,6 +298,9 @@ static int vimc_sen_s_ctrl(struct v4l2_ctrl *ctrl)
>   	case V4L2_CID_SATURATION:
>   		tpg_s_saturation(&vsen->tpg, ctrl->val);
>   		break;
> +	case VIMC_CID_SHOW_INFO:
> +		vsen->show_info = ctrl->val;
> +		break;
>   	default:
>   		return -EINVAL;
>   	}
> @@ -307,6 +339,17 @@ static const struct v4l2_ctrl_config vimc_sen_ctrl_test_pattern = {
>   	.qmenu = tpg_pattern_strings,
>   };
>   
> +static const struct v4l2_ctrl_config vimc_sen_ctrl_show_info = {
> +	.ops = &vimc_sen_ctrl_ops,
> +	.id = VIMC_CID_SHOW_INFO,
> +	.name = "Show Information",
> +	.type = V4L2_CTRL_TYPE_BOOLEAN,
> +	.min = 0,
> +	.max = 1,
> +	.step = 1,
> +	.def = 1,
> +};
> +
>   static struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
>   					    const char *vcfg_name)
>   {
> @@ -323,6 +366,7 @@ static struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
>   
>   	v4l2_ctrl_new_custom(&vsen->hdl, &vimc_sen_ctrl_class, NULL);
>   	v4l2_ctrl_new_custom(&vsen->hdl, &vimc_sen_ctrl_test_pattern, NULL);
> +	v4l2_ctrl_new_custom(&vsen->hdl, &vimc_sen_ctrl_show_info, NULL);
>   	v4l2_ctrl_new_std(&vsen->hdl, &vimc_sen_ctrl_ops,
>   			  V4L2_CID_VFLIP, 0, 1, 1, 0);
>   	v4l2_ctrl_new_std(&vsen->hdl, &vimc_sen_ctrl_ops,
> @@ -362,6 +406,7 @@ static struct vimc_ent_device *vimc_sen_add(struct vimc_device *vimc,
>   
>   	/* Initialize the frame format */
>   	vsen->mbus_format = fmt_default;
> +	vsen->show_info = vimc_sen_ctrl_show_info.def;
>   
>   	return &vsen->ved;
>   
>