From: Jonathan Corbet Date: Tue, 22 May 2007 03:39:00 +0000 (-0300) Subject: V4L/DVB (5691): Ov7670: reset clkrc in rgb565 mode X-Git-Tag: firefly_0821_release~28969^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=edd75ede2d40eadb98e07d87e88fa970f86ffe9e;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Mauro Carvalho Chehab --- 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 @@ -720,11 +720,21 @@ 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 @@ -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: