Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v2] media: vimc: Implement debayer control for mean window
 size
To:     Shuah Khan <skhan@linuxfoundation.org>,
        Arthur Moraes do Lago <arthurmoraeslago@gmail.com>,
        mchehab@kernel.org, helen.koike@collabora.com,
        andrealmeid@collabora.com, laispc19@gmail.com,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20190917225317.5872-1-arthurmoraeslago@gmail.com>
 <39078cb4-1ea5-e97e-0323-0318b42910c6@linuxfoundation.org>
From:   Hans Verkuil <hverkuil-cisco@xs4all.nl>
Message-ID: <e0035c20-ae4b-2f9e-e833-cd3dbe4eaf77@xs4all.nl>
Date:   Thu, 19 Sep 2019 10:20:39 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.6.1
MIME-Version: 1.0
In-Reply-To: <39078cb4-1ea5-e97e-0323-0318b42910c6@linuxfoundation.org>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 9/18/19 1:12 AM, Shuah Khan wrote:
> On 9/17/19 4:53 PM, Arthur Moraes do Lago wrote:
>> Add mean window size parameter for debayer filter as a control in
>> vimc-debayer.
>>
>> vimc-debayer was patched to allow changing mean windows parameter
>> of the filter without needing to reload the driver. The parameter
>> can now be set using a v4l2-ctl control(mean_window_size).
>>
>> Co-developed-by: Laís Pessine do Carmo <laispc19@gmail.com>
>> Signed-off-by: Laís Pessine do Carmo <laispc19@gmail.com>
>> Signed-off-by: Arthur Moraes do Lago <arthurmoraeslago@gmail.com>
>>
>> Small fixes to vimc debayer mean window size patch
>> ---
>> Changes in V2:
>>   - Updated documentation
>>   - Added v4l2_subev_core_ops to solve errors in v4l2-ctl compliance test
>>   - Changed control naming to follow English capitalization rules
>>   - Rebased to Shuah Khan's newest patch series 171283
>>      ("Collapse vimc single monolithic driver")
>>   - Change maximum value for mean window size
>>
>> We did run streaming tests, the value of 1 for mean window size has a
>> nice side effect of not applying any filter, so we can see the original
>> pattern. The value of 99 for mean window size worked, but was very slow.
>> We wanted to find a way to show that higher values for mean window size
>> yielded very similar results to just blurring the image, but we could
>> not find any way to show this, so we just made the maximum value 25,
>> which runs faster, but is still probably a little high.
>> ---
>>   Documentation/media/v4l-drivers/vimc.rst   | 10 +--
>>   drivers/media/platform/vimc/vimc-common.h  |  1 +
>>   drivers/media/platform/vimc/vimc-debayer.c | 89 +++++++++++++++++++---
>>   3 files changed, 79 insertions(+), 21 deletions(-)
>>
>> diff --git a/Documentation/media/v4l-drivers/vimc.rst b/Documentation/media/v4l-drivers/vimc.rst
>> index a582af0509ee..91c909904b87 100644
>> --- a/Documentation/media/v4l-drivers/vimc.rst
>> +++ b/Documentation/media/v4l-drivers/vimc.rst
>> @@ -80,9 +80,7 @@ vimc-capture:
>>           Module options
>>   ---------------
>>   -Vimc has a few module parameters to configure the driver.
>> -
>> -        param=value
>> +Vimc has a module parameters to configure the driver.
> 
> parameter
> 
>>     * ``sca_mult=<unsigned int>``
>>   @@ -91,12 +89,6 @@ Vimc has a few module parameters to configure the driver.
>>           original one. Currently, only supports scaling up (the default value
>>           is 3).
>>   -* ``deb_mean_win_size=<unsigned int>``
>> -
>> -        Window size to calculate the mean. Note: the window size needs to be an
>> -        odd number, as the main pixel stays in the center of the window,
>> -        otherwise the next odd number is considered (the default value is 3).
>> -
>>   Source code documentation
>>   -------------------------
>>   diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
>> index 236412ad7548..3a5102ddf794 100644
>> --- a/drivers/media/platform/vimc/vimc-common.h
>> +++ b/drivers/media/platform/vimc/vimc-common.h
>> @@ -19,6 +19,7 @@
>>   #define VIMC_CID_VIMC_BASE        (0x00f00000 | 0xf000)
>>   #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_FRAME_MAX_WIDTH 4096
>>   #define VIMC_FRAME_MAX_HEIGHT 2160
>> diff --git a/drivers/media/platform/vimc/vimc-debayer.c b/drivers/media/platform/vimc/vimc-debayer.c
>> index 37f3767db469..76df2ac110c0 100644
>> --- a/drivers/media/platform/vimc/vimc-debayer.c
>> +++ b/drivers/media/platform/vimc/vimc-debayer.c
>> @@ -11,17 +11,12 @@
>>   #include <linux/platform_device.h>
>>   #include <linux/vmalloc.h>
>>   #include <linux/v4l2-mediabus.h>
>> +#include <media/v4l2-ctrls.h>
>> +#include <media/v4l2-event.h>
>>   #include <media/v4l2-subdev.h>
>>     #include "vimc-common.h"
>>   -static unsigned int deb_mean_win_size = 3;
>> -module_param(deb_mean_win_size, uint, 0000);
>> -MODULE_PARM_DESC(deb_mean_win_size, " the window size to calculate the mean.\n"
>> -    "NOTE: the window size needs to be an odd number, as the main pixel "
>> -    "stays in the center of the window, otherwise the next odd number "
>> -    "is considered");
>> -
>>   enum vimc_deb_rgb_colors {
>>       VIMC_DEB_RED = 0,
>>       VIMC_DEB_GREEN = 1,
>> @@ -46,6 +41,8 @@ struct vimc_deb_device {
>>       u8 *src_frame;
>>       const struct vimc_deb_pix_map *sink_pix_map;
>>       unsigned int sink_bpp;
>> +    unsigned int mean_win_size;
>> +    struct v4l2_ctrl_handler hdl;
>>   };
>>     static const struct v4l2_mbus_framefmt sink_fmt_default = {
>> @@ -346,11 +343,18 @@ static int vimc_deb_s_stream(struct v4l2_subdev *sd, int enable)
>>       return 0;
>>   }
>>   +static const struct v4l2_subdev_core_ops vimc_deb_core_ops = {
>> +    .log_status = v4l2_ctrl_subdev_log_status,
>> +    .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
>> +    .unsubscribe_event = v4l2_event_subdev_unsubscribe,
>> +};
>> +
>>   static const struct v4l2_subdev_video_ops vimc_deb_video_ops = {
>>       .s_stream = vimc_deb_s_stream,
>>   };
>>     static const struct v4l2_subdev_ops vimc_deb_ops = {
>> +    .core = &vimc_deb_core_ops,
>>       .pad = &vimc_deb_pad_ops,
>>       .video = &vimc_deb_video_ops,
>>   };
>> @@ -384,7 +388,7 @@ static void vimc_deb_calc_rgb_sink(struct vimc_deb_device *vdeb,
>>        * the top left corner of the mean window (considering the current
>>        * pixel as the center)
>>        */
>> -    seek = deb_mean_win_size / 2;
>> +    seek = vdeb->mean_win_size / 2;
>>         /* Sum the values of the colors in the mean window */
>>   @@ -474,6 +478,33 @@ static void *vimc_deb_process_frame(struct vimc_ent_device *ved,
>>     }
>>   +static inline void vimc_deb_s_mean_win_size(struct vimc_deb_device *vdeb,
>> +                        unsigned int mean_win_size)
>> +{
>> +    if (vdeb->mean_win_size == mean_win_size)
>> +        return;
>> +    vdeb->mean_win_size = mean_win_size;
>> +}
>> +
>> +static int vimc_deb_s_ctrl(struct v4l2_ctrl *ctrl)
>> +{
>> +    struct vimc_deb_device *vdeb =
>> +        container_of(ctrl->handler, struct vimc_deb_device, hdl);
>> +
>> +    switch (ctrl->id) {
>> +    case VIMC_CID_MEAN_WIN_SIZE:
>> +        vimc_deb_s_mean_win_size(vdeb, ctrl->val);
>> +        break;
>> +    default:
>> +        return -EINVAL;
>> +    }
>> +    return 0;
>> +}
>> +
>> +static const struct v4l2_ctrl_ops vimc_deb_ctrl_ops = {
>> +    .s_ctrl = vimc_deb_s_ctrl,
>> +};
>> +
>>   static void vimc_deb_release(struct v4l2_subdev *sd)
>>   {
>>       struct vimc_deb_device *vdeb =
>> @@ -495,6 +526,24 @@ void vimc_deb_rm(struct vimc_device *vimc, struct vimc_ent_device *ved)
>>       vimc_ent_sd_unregister(ved, &vdeb->sd);
>>   }
>>   +static const struct v4l2_ctrl_config vimc_deb_ctrl_class = {
>> +    .flags = V4L2_CTRL_FLAG_READ_ONLY | V4L2_CTRL_FLAG_WRITE_ONLY,
>> +    .id = VIMC_CID_VIMC_CLASS,
>> +    .name = "VIMC Controls",
> 
> Make this VIMC Debayer Controls?

Actually, no. This control class is similar to the "Vivid Controls" in the vivid
driver: it collects all VIMC specific controls. It's only Debayer for now, but others
will be added here as well.

> 
>> +    .type = V4L2_CTRL_TYPE_CTRL_CLASS,
>> +};
>> +
>> +static const struct v4l2_ctrl_config vimc_deb_ctrl_mean_win_size = {
>> +    .ops = &vimc_deb_ctrl_ops,
>> +    .id = VIMC_CID_MEAN_WIN_SIZE,
>> +    .name = "Mean Window Size",

But it would be useful to change this to:

"Debayer Mean Window Size"

Regards,

	Hans

>> +    .type = V4L2_CTRL_TYPE_INTEGER,
>> +    .min = 1,
>> +    .max = 25,
>> +    .step = 2,
>> +    .def = 3,
>> +};
>> +
>>   struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
>>                        const char *vcfg_name)
>>   {
>> @@ -507,6 +556,16 @@ struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
>>       if (!vdeb)
>>           return NULL;
>>   +    /* Create controls: */
>> +    v4l2_ctrl_handler_init(&vdeb->hdl, 2);
>> +    v4l2_ctrl_new_custom(&vdeb->hdl, &vimc_deb_ctrl_class, NULL);
>> +    v4l2_ctrl_new_custom(&vdeb->hdl, &vimc_deb_ctrl_mean_win_size, NULL);
>> +    vdeb->sd.ctrl_handler = &vdeb->hdl;
>> +    if (vdeb->hdl.error) {
>> +        ret = vdeb->hdl.error;
>> +        goto err_free_vdeb;
>> +    }
>> +
>>       /* Initialize ved and sd */
>>       ret = vimc_ent_sd_register(&vdeb->ved, &vdeb->sd, v4l2_dev,
>>                      vcfg_name,
>> @@ -514,13 +573,12 @@ struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
>>                      (const unsigned long[2]) {MEDIA_PAD_FL_SINK,
>>                      MEDIA_PAD_FL_SOURCE},
>>                      &vimc_deb_int_ops, &vimc_deb_ops);
>> -    if (ret) {
>> -        kfree(vdeb);
>> -        return NULL;
>> -    }
>> +    if (ret)
>> +        goto err_free_hdl;
>>         vdeb->ved.process_frame = vimc_deb_process_frame;
>>       vdeb->dev = &vimc->pdev.dev;
>> +    vdeb->mean_win_size = vimc_deb_ctrl_mean_win_size.def;
>>         /* Initialize the frame format */
>>       vdeb->sink_fmt = sink_fmt_default;
>> @@ -534,4 +592,11 @@ struct vimc_ent_device *vimc_deb_add(struct vimc_device *vimc,
>>       vdeb->set_rgb_src = vimc_deb_set_rgb_mbus_fmt_rgb888_1x24;
>>         return &vdeb->ved;
>> +
>> +err_free_hdl:
>> +    v4l2_ctrl_handler_free(&vdeb->hdl);
> 
> Free the handle from vimc_deb_release()
> 
>> +err_free_vdeb:
>> +    kfree(vdeb);
>> +
>> +    return NULL;
>>   }
>>
> 
> thanks,
> -- Shuah