Reduce parallel port rate according to maximum pixel clock frequency
admissible by camera interface.
This allows to support any resolutions/framerate requests by decreasing
the framerate according to maximum camera interface capabilities.
Signed-off-by: Hugues Fruchet <hugues.fruchet@xxxxxx>
---
drivers/media/i2c/ov5640.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index da4d754..9f3c32e 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -918,6 +918,8 @@ static int ov5640_set_dvp_pclk(struct ov5640_dev *sensor,
{
u8 prediv, mult, sysdiv, pll_rdiv, bit_div, pclk_div;
int ret;
+ struct i2c_client *client = sensor->i2c_client;
+ unsigned int pclk_freq, max_pclk_freq;
/*
* FIXME, value of PCLK divider deduced from
* mode registers hardcoded sequence and tests
@@ -941,6 +943,16 @@ static int ov5640_set_dvp_pclk(struct ov5640_dev *sensor,
if (ret)
return ret;
+ pclk_freq = rate / dvp_pclk_divider;
+ max_pclk_freq = sensor->ep.bus.parallel.pclk_max_frequency;
+
+ /* clip rate according to optional maximum pixel clock limit */
+ if (max_pclk_freq && pclk_freq > max_pclk_freq) {
+ rate = max_pclk_freq * dvp_pclk_divider;
+ dev_dbg(&client->dev, "DVP pixel clock too high (%d > %d Hz), reducing rate...\n",
+ pclk_freq, max_pclk_freq);
+ }
+
ov5640_calc_pclk(sensor, rate, &prediv, &mult, &sysdiv, &pll_rdiv,
&bit_div, &pclk_div);
--
2.7.4
