media: mt9p031: Read back the real clock rate

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>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
index 6eb88ef..9dea7c8 100644 (file)
--- a/drivers/media/i2c/mt9p031.c
+++ b/drivers/media/i2c/mt9p031.c
@@ -229,6 +229,7 @@ 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);
@@ -239,13 +240,15 @@ 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);
@@ -254,7 +257,7 @@ 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;