From 04ee6d92047e1ac68d4eb615119343f4f0fc57db Mon Sep 17 00:00:00 2001 From: Javier Martin Date: Tue, 29 Jan 2013 07:23:42 -0300 Subject: [PATCH] [media] media: ov7670: add possibility to bypass pll for ov7675 For a frame rate of 30 fps a pixclk of 24MHz is needed. For those cases where the ov7670 has a clean 24MHz input (xvclk) the PLL can be bypassed. This will result in a value of clkrc of 1, which means that in practice pixclk = xvclk (input clock) Acked-by: Jonathan Corbet Signed-off-by: Javier Martin Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/ov7670.c | 28 ++++++++++++++++++++++++++-- include/media/ov7670.h | 1 + 2 files changed, 27 insertions(+), 2 deletions(-) diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c index dea2917a2b12..3e503396aaa4 100644 --- a/drivers/media/i2c/ov7670.c +++ b/drivers/media/i2c/ov7670.c @@ -230,6 +230,7 @@ struct ov7670_info { int clock_speed; /* External clock speed (MHz) */ u8 clkrc; /* Clock divider value */ bool use_smbus; /* Use smbus I/O instead of I2C */ + bool pll_bypass; const struct ov7670_devtype *devtype; /* Device specifics */ }; @@ -755,7 +756,12 @@ static void ov7675_get_framerate(struct v4l2_subdev *sd, { struct ov7670_info *info = to_state(sd); u32 clkrc = info->clkrc; - u32 pll_factor = PLL_FACTOR; + int pll_factor; + + if (info->pll_bypass) + pll_factor = 1; + else + pll_factor = PLL_FACTOR; clkrc++; if (info->fmt->mbus_code == V4L2_MBUS_FMT_SBGGR8_1X8) @@ -771,7 +777,7 @@ static int ov7675_set_framerate(struct v4l2_subdev *sd, { struct ov7670_info *info = to_state(sd); u32 clkrc; - u32 pll_factor = PLL_FACTOR; + int pll_factor; int ret; /* @@ -781,6 +787,16 @@ static int ov7675_set_framerate(struct v4l2_subdev *sd, * pixclk = clock_speed / (clkrc + 1) * PLLfactor * */ + if (info->pll_bypass) { + pll_factor = 1; + ret = ov7670_write(sd, REG_DBLV, DBLV_BYPASS); + } else { + pll_factor = PLL_FACTOR; + ret = ov7670_write(sd, REG_DBLV, DBLV_X4); + } + if (ret < 0) + return ret; + if (tpf->numerator == 0 || tpf->denominator == 0) { clkrc = 0; } else { @@ -808,6 +824,7 @@ static int ov7675_set_framerate(struct v4l2_subdev *sd, ret = ov7670_write(sd, REG_CLKRC, info->clkrc); if (ret < 0) return ret; + return ov7670_write(sd, REG_DBLV, DBLV_X4); } @@ -1688,6 +1705,13 @@ static int ov7670_probe(struct i2c_client *client, if (config->clock_speed) info->clock_speed = config->clock_speed; + + /* + * It should be allowed for ov7670 too when it is migrated to + * the new frame rate formula. + */ + if (config->pll_bypass && id->driver_data != MODEL_OV7670) + info->pll_bypass = true; } /* Make sure it's an ov7670 */ diff --git a/include/media/ov7670.h b/include/media/ov7670.h index b133bc123031..a68c8bb3ceba 100644 --- a/include/media/ov7670.h +++ b/include/media/ov7670.h @@ -15,6 +15,7 @@ struct ov7670_config { int min_height; /* Filter out smaller sizes */ int clock_speed; /* External clock speed (MHz) */ bool use_smbus; /* Use smbus I/O instead of I2C */ + bool pll_bypass; /* Choose whether to bypass the PLL */ }; #endif -- 2.20.1