From d8d201552f518370d0a64cb758684f667fdd2012 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Sun, 20 Dec 2009 11:39:47 -0300 Subject: [PATCH] V4L/DVB: ov7670: Avoid reading clkrc Reading the clkrc register creates flaky behavior in some situations, and we can easily track its state separately. Signed-off-by: Jonathan Corbet Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/ov7670.c | 45 +++++++++++++++--------------------- 1 file changed, 18 insertions(+), 27 deletions(-) diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c index b44762adb1e9..b2e6f8e730a3 100644 --- a/drivers/media/video/ov7670.c +++ b/drivers/media/video/ov7670.c @@ -198,6 +198,7 @@ struct ov7670_info { struct ov7670_format_struct *fmt; /* Current format */ unsigned char sat; /* Saturation value */ int hue; /* Hue value */ + u8 clkrc; /* Clock divider value */ }; static inline struct ov7670_info *to_state(struct v4l2_subdev *sd) @@ -744,21 +745,11 @@ static int ov7670_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *fmt) struct ov7670_format_struct *ovfmt; struct ov7670_win_size *wsize; struct ov7670_info *info = to_state(sd); - unsigned char com7, clkrc = 0; + unsigned char com7; ret = ov7670_try_fmt_internal(sd, 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(sd, 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 @@ -779,8 +770,14 @@ static int ov7670_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *fmt) ret = ov7670_write_array(sd, wsize->regs); info->fmt = ovfmt; + /* + * If we're running RGB565, we must rewrite clkrc after setting + * the other parameters or the image looks poor. If we're *not* + * doing RGB565, we must not rewrite clkrc or the image looks + * *really* poor. + */ if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565 && ret == 0) - ret = ov7670_write(sd, REG_CLKRC, clkrc); + ret = ov7670_write(sd, REG_CLKRC, info->clkrc); return ret; } @@ -791,20 +788,17 @@ static int ov7670_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *fmt) static int ov7670_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms) { struct v4l2_captureparm *cp = &parms->parm.capture; - unsigned char clkrc; - int ret; + struct ov7670_info *info = to_state(sd); if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE) return -EINVAL; - ret = ov7670_read(sd, REG_CLKRC, &clkrc); - if (ret < 0) - return ret; + memset(cp, 0, sizeof(struct v4l2_captureparm)); cp->capability = V4L2_CAP_TIMEPERFRAME; cp->timeperframe.numerator = 1; cp->timeperframe.denominator = OV7670_FRAME_RATE; - if ((clkrc & CLK_EXT) == 0 && (clkrc & CLK_SCALE) > 1) - cp->timeperframe.denominator /= (clkrc & CLK_SCALE); + if ((info->clkrc & CLK_EXT) == 0 && (info->clkrc & CLK_SCALE) > 1) + cp->timeperframe.denominator /= (info->clkrc & CLK_SCALE); return 0; } @@ -812,6 +806,7 @@ static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms) { struct v4l2_captureparm *cp = &parms->parm.capture; struct v4l2_fract *tpf = &cp->timeperframe; + struct ov7670_info *info = to_state(sd); unsigned char clkrc; int ret, div; @@ -819,12 +814,7 @@ static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms) return -EINVAL; if (cp->extendedmode != 0) return -EINVAL; - /* - * CLKRC has a reserved bit, so let's preserve it. - */ - ret = ov7670_read(sd, REG_CLKRC, &clkrc); - if (ret < 0) - return ret; + if (tpf->numerator == 0 || tpf->denominator == 0) div = 1; /* Reset to full rate */ else @@ -833,10 +823,10 @@ static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms) div = 1; else if (div > CLK_SCALE) div = CLK_SCALE; - clkrc = (clkrc & 0x80) | div; + info->clkrc = (info->clkrc & 0x80) | div; tpf->numerator = 1; tpf->denominator = OV7670_FRAME_RATE/div; - return ov7670_write(sd, REG_CLKRC, clkrc); + return ov7670_write(sd, REG_CLKRC, info->clkrc); } @@ -1268,6 +1258,7 @@ static int ov7670_probe(struct i2c_client *client, info->fmt = &ov7670_formats[0]; info->sat = 128; /* Review this */ + info->clkrc = 1; /* 30fps */ return 0; } -- 2.34.1