[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 <corbet@lwn.net> Signed-off-by: Javier Martin <javier.martin@vista-silicon.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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@ -230,6 +230,7 @@ struct ov7670_info {
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int clock_speed; /* External clock speed (MHz) */
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u8 clkrc; /* Clock divider value */
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bool use_smbus; /* Use smbus I/O instead of I2C */
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bool pll_bypass;
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const struct ov7670_devtype *devtype; /* Device specifics */
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};
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@ -755,7 +756,12 @@ static void ov7675_get_framerate(struct v4l2_subdev *sd,
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{
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struct ov7670_info *info = to_state(sd);
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u32 clkrc = info->clkrc;
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u32 pll_factor = PLL_FACTOR;
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int pll_factor;
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if (info->pll_bypass)
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pll_factor = 1;
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else
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pll_factor = PLL_FACTOR;
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clkrc++;
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if (info->fmt->mbus_code == V4L2_MBUS_FMT_SBGGR8_1X8)
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@ -771,7 +777,7 @@ static int ov7675_set_framerate(struct v4l2_subdev *sd,
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{
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struct ov7670_info *info = to_state(sd);
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u32 clkrc;
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u32 pll_factor = PLL_FACTOR;
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int pll_factor;
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int ret;
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/*
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@ -781,6 +787,16 @@ static int ov7675_set_framerate(struct v4l2_subdev *sd,
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* pixclk = clock_speed / (clkrc + 1) * PLLfactor
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*
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*/
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if (info->pll_bypass) {
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pll_factor = 1;
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ret = ov7670_write(sd, REG_DBLV, DBLV_BYPASS);
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} else {
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pll_factor = PLL_FACTOR;
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ret = ov7670_write(sd, REG_DBLV, DBLV_X4);
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}
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if (ret < 0)
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return ret;
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if (tpf->numerator == 0 || tpf->denominator == 0) {
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clkrc = 0;
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} else {
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@ -808,6 +824,7 @@ static int ov7675_set_framerate(struct v4l2_subdev *sd,
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ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
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if (ret < 0)
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return ret;
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return ov7670_write(sd, REG_DBLV, DBLV_X4);
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}
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@ -1688,6 +1705,13 @@ static int ov7670_probe(struct i2c_client *client,
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if (config->clock_speed)
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info->clock_speed = config->clock_speed;
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/*
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* It should be allowed for ov7670 too when it is migrated to
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* the new frame rate formula.
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*/
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if (config->pll_bypass && id->driver_data != MODEL_OV7670)
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info->pll_bypass = true;
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}
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/* Make sure it's an ov7670 */
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@ -15,6 +15,7 @@ struct ov7670_config {
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int min_height; /* Filter out smaller sizes */
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int clock_speed; /* External clock speed (MHz) */
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bool use_smbus; /* Use smbus I/O instead of I2C */
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bool pll_bypass; /* Choose whether to bypass the PLL */
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};
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#endif
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