[RFC PATCH] vimc: Add colors' order over test image

[Kaaira Gupta <kgupta@es.iitr.ac.in>]

Currently there is no method to know if the test image generated by vimc
is correct (except for comparing it with a known 'correct' image). Add
text over the test image, representing the correct order of colors.

I have sent it as an RFC because we can add the text as an optional
control, and maybe we can print some other useful information as well
(like vivid does).

Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in>
---
 drivers/media/test-drivers/vimc/Kconfig       | 2 ++
 drivers/media/test-drivers/vimc/vimc-core.c   | 9 +++++++++
 drivers/media/test-drivers/vimc/vimc-sensor.c | 8 ++++++++
 3 files changed, 19 insertions(+)

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-core.c b/drivers/media/test-drivers/vimc/vimc-core.c
index 11210aaa2551..8142bfbcbd49 100644
--- a/drivers/media/test-drivers/vimc/vimc-core.c
+++ b/drivers/media/test-drivers/vimc/vimc-core.c
@@ -5,10 +5,12 @@
  * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
  */
 
+#include <linux/font.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <media/media-device.h>
+#include <media/tpg/v4l2-tpg.h>
 #include <media/v4l2-device.h>
 
 #include "vimc-common.h"
@@ -265,7 +267,14 @@ static int vimc_probe(struct platform_device *pdev)
 {
 	struct vimc_device *vimc;
 	int ret;
+	const struct font_desc *font = find_font("VGA8x16");
 
+	if (font == NULL) {
+		pr_err("vimc: could not find font\n");
+		return -ENODEV;
+	}
+
+	tpg_set_font(font->data);
 	dev_dbg(&pdev->dev, "probe");
 
 	vimc = kzalloc(sizeof(*vimc), GFP_KERNEL);
diff --git a/drivers/media/test-drivers/vimc/vimc-sensor.c b/drivers/media/test-drivers/vimc/vimc-sensor.c
index a2f09ac9a360..4b13955c502a 100644
--- a/drivers/media/test-drivers/vimc/vimc-sensor.c
+++ b/drivers/media/test-drivers/vimc/vimc-sensor.c
@@ -185,10 +185,18 @@ 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 str[100];
 	struct vimc_sen_device *vsen = container_of(ved, struct vimc_sen_device,
 						    ved);
 
+	tpg_calc_text_basep(&vsen->tpg, basep, 0, vsen->frame);
 	tpg_fill_plane_buffer(&vsen->tpg, 0, 0, vsen->frame);
+
+	snprintf(str, sizeof(str),
+		 "Order: white, yellow, cyan, green, magenta, red, blue, black");
+	tpg_gen_text(&vsen->tpg, basep, 1, 1, str);
+
 	return vsen->frame;
 }
 
-- 
2.17.1