diff mbox series

[4/4] media: ov5640: reduce rate according to maximum pixel clock frequency

Message ID 1538059567-8381-5-git-send-email-hugues.fruchet@st.com (mailing list archive)
State New, archived
Headers show
Series OV5640: reduce rate according to maximum pixel clock | expand

Commit Message

Hugues FRUCHET Sept. 27, 2018, 2:46 p.m. UTC 
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@st.com>
---
 drivers/media/i2c/ov5640.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

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);