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authorJonathan Corbet <corbet@lwn.net>2007-05-22 00:39:00 -0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2007-05-22 16:16:29 -0300
commitedd75ede2d40eadb98e07d87e88fa970f86ffe9e (patch)
treeded1750d0bf6345d348573c8486e874b86dfd12e /drivers/media/video/ov7670.c
parent7acf90c70c6ee063f7465b2f10e2083bc49f355b (diff)
downloadlinux-edd75ede2d40eadb98e07d87e88fa970f86ffe9e.tar.gz
V4L/DVB (5691): Ov7670: reset clkrc in rgb565 mode
A bug in the ov7670 sensor causes it to introduce noise unless the CLKRC
register is rewritten *after* setting the image mode.  Naturally,
resetting CLKRC in this way will cause other modes to fail.  So
carefully poke the register only when indicated.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers/media/video/ov7670.c')
-rw-r--r--drivers/media/video/ov7670.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c
index 03bc369a9e49..3ceb8a6249dd 100644
--- a/drivers/media/video/ov7670.c
+++ b/drivers/media/video/ov7670.c
@@ -720,12 +720,22 @@ static int ov7670_s_fmt(struct i2c_client *c, struct v4l2_format *fmt)
 	struct ov7670_format_struct *ovfmt;
 	struct ov7670_win_size *wsize;
 	struct ov7670_info *info = i2c_get_clientdata(c);
-	unsigned char com7;
+	unsigned char com7, clkrc;
 
 	ret = ov7670_try_fmt(c, fmt, &ovfmt, &wsize);
 	if (ret)
 		return ret;
 	/*
+	 * HACK: if we're running rgb565 we need to grab then rewrite
+	 * CLKRC.  If we're *not*, however, then rewriting clkrc hoses
+	 * the colors.
+	 */
+	if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565) {
+		ret = ov7670_read(c, REG_CLKRC, &clkrc);
+		if (ret)
+			return ret;
+	}
+	/*
 	 * COM7 is a pain in the ass, it doesn't like to be read then
 	 * quickly written afterward.  But we have everything we need
 	 * to set it absolutely here, as long as the format-specific
@@ -744,7 +754,10 @@ static int ov7670_s_fmt(struct i2c_client *c, struct v4l2_format *fmt)
 	if (wsize->regs)
 		ret = ov7670_write_array(c, wsize->regs);
 	info->fmt = ovfmt;
-	return 0;
+
+	if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565 && ret == 0)
+		ret = ov7670_write(c, REG_CLKRC, clkrc);
+	return ret;
 }
 
 /*
@@ -1267,7 +1280,9 @@ static int ov7670_attach(struct i2c_adapter *adapter)
 	ret = ov7670_detect(client);
 	if (ret)
 		goto out_free_info;
-	i2c_attach_client(client);
+	ret = i2c_attach_client(client);
+	if (ret)
+		goto out_free_info;
 	return 0;
 
   out_free_info: