[PATCH v3 1/6] media: mt9p031: Read back the real clock rate

Stefan Riedmueller
2021-07-02T09:59:36Z

From: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>

The real and requested clock can differ and because it is used to
calculate PLL values, the real clock rate should be read.

Signed-off-by: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
drivers/media/i2c/mt9p031.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
index 77567341ec98..3eaaa8d44523 100644
--- a/drivers/media/i2c/mt9p031.c
+++ b/drivers/media/i2c/mt9p031.c
@@ -255,6 +255,7 @@ static int mt9p031_clk_setup(struct mt9p031 *mt9p031)

struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
struct mt9p031_platform_data *pdata = mt9p031->pdata;
+ unsigned long ext_freq;
int ret;

mt9p031->clk = devm_clk_get(&client->dev, NULL);
@@ -265,13 +266,15 @@ static int mt9p031_clk_setup(struct mt9p031 *mt9p031)
if (ret < 0)
return ret;

+ ext_freq = clk_get_rate(mt9p031->clk);
+
/* If the external clock frequency is out of bounds for the PLL use the
* pixel clock divider only and disable the PLL.
*/
- if (pdata->ext_freq > limits.ext_clock_max) {
+ if (ext_freq > limits.ext_clock_max) {
unsigned int div;

- div = DIV_ROUND_UP(pdata->ext_freq, pdata->target_freq);
+ div = DIV_ROUND_UP(ext_freq, pdata->target_freq);
div = roundup_pow_of_two(div) / 2;

mt9p031->clk_div = min_t(unsigned int, div, 64);
@@ -280,7 +283,7 @@ static int mt9p031_clk_setup(struct mt9p031 *mt9p031)
return 0;
}

- mt9p031->pll.ext_clock = pdata->ext_freq;
+ mt9p031->pll.ext_clock = ext_freq;
mt9p031->pll.pix_clock = pdata->target_freq;
mt9p031->use_pll = true;

--
2.25.1