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From:   Arthur Moraes do Lago <arthurmoraeslago@gmail.com>
To:     helen.koike@collabora.com, mchehab@kernel.org,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        lkcamp@lists.libreplanetbr.org
Subject: [PATCH] media: vimc: Implement debayer control for mean window size
Date:   Sun,  1 Sep 2019 16:40:31 -0300
Message-Id: <20190901194032.16207-1-arthurmoraeslago@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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>

---
This patch was made on top of Shuah Khan's patch (162623).
Thanks.
---
 drivers/media/platform/vimc/vimc-common.h  |  1 +
 drivers/media/platform/vimc/vimc-debayer.c | 81 ++++++++++++++++++----
 2 files changed, 70 insertions(+), 12 deletions(-)

diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
index 5b2282de395c..547ff04a415e 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 6cee911bf149..aa3edeed96bc 100644
--- a/drivers/media/platform/vimc/vimc-debayer.c
+++ b/drivers/media/platform/vimc/vimc-debayer.c
@@ -11,17 +11,11 @@
 #include <linux/platform_device.h>
 #include <linux/vmalloc.h>
 #include <linux/v4l2-mediabus.h>
+#include <media/v4l2-ctrls.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");
-
 #define IS_SINK(pad) (!pad)
 #define IS_SRC(pad)  (pad)
 
@@ -49,6 +43,8 @@ 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 = {
@@ -387,7 +383,7 @@ 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 */
 
@@ -477,6 +473,33 @@ 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 =
@@ -502,6 +525,24 @@ void vimc_deb_rm(struct vimc_device *vimc, struct vimc_ent_config *vcfg)
 	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",
+	.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",
+	.type = V4L2_CTRL_TYPE_INTEGER,
+	.min = 1,
+	.max = 99,
+	.step = 2,
+	.def = 3,
+};
+
 int vimc_deb_add(struct vimc_device *vimc, struct vimc_ent_config *vcfg)
 {
 	struct v4l2_device *v4l2_dev = &vimc->v4l2_dev;
@@ -513,6 +554,16 @@ int vimc_deb_add(struct vimc_device *vimc, struct vimc_ent_config *vcfg)
 	if (!vdeb)
 		return -ENOMEM;
 
+	/* 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,
@@ -520,13 +571,12 @@ int vimc_deb_add(struct vimc_device *vimc, struct vimc_ent_config *vcfg)
 				   (const unsigned long[2]) {MEDIA_PAD_FL_SINK,
 				   MEDIA_PAD_FL_SOURCE},
 				   &vimc_deb_int_ops, &vimc_deb_ops);
-	if (ret) {
-		kfree(vdeb);
-		return ret;
-	}
+	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;
@@ -541,4 +591,11 @@ int vimc_deb_add(struct vimc_device *vimc, struct vimc_ent_config *vcfg)
 
 	vcfg->ved = &vdeb->ved;
 	return 0;
+
+err_free_hdl:
+	v4l2_ctrl_handler_free(&vdeb->hdl);
+err_free_vdeb:
+	kfree(vdeb);
+
+	return ret;
 }
-- 
2.23.0