Check that the PLL1 output frequency does not exceed the maximum allowed 1GHz
frequency.
Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
---
drivers/media/i2c/ov5640.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index e098435..1f2e72d 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -770,7 +770,7 @@ static int ov5640_mod_reg(struct ov5640_dev *sensor, u16 reg,
* always set to either 1 or 2 in the vendor kernels.
*/
#define OV5640_SYSDIV_MIN 1
-#define OV5640_SYSDIV_MAX 2
+#define OV5640_SYSDIV_MAX 16
/*
* This is supposed to be ranging from 1 to 16, but the value is always
@@ -806,15 +806,20 @@ static int ov5640_mod_reg(struct ov5640_dev *sensor, u16 reg,
* This is supposed to be ranging from 1 to 8, but the value is always
* set to 1 in the vendor kernels.
*/
-#define OV5640_PCLK_ROOT_DIV 1
+#define OV5640_PCLK_ROOT_DIV 1
+#define OV5640_PLL_SYS_ROOT_DIVIDER_BYPASS 0x00
static unsigned long ov5640_compute_sys_clk(struct ov5640_dev *sensor,
u8 pll_prediv, u8 pll_mult,
u8 sysdiv)
{
- unsigned long rate = clk_get_rate(sensor->xclk);
+ unsigned long sysclk = sensor->xclk_freq / pll_prediv * pll_mult;
- return rate / pll_prediv * pll_mult / sysdiv;
+ /* PLL1 output cannot exceed 1GHz. */
+ if (sysclk / 1000000 > 1000)
+ return 0;
+
+ return sysclk / sysdiv;
}
static unsigned long ov5640_calc_sys_clk(struct ov5640_dev *sensor,
@@ -844,6 +849,16 @@ static unsigned long ov5640_calc_sys_clk(struct ov5640_dev *sensor,
_rate = ov5640_compute_sys_clk(sensor,
OV5640_PLL_PREDIV,
_pll_mult, _sysdiv);
+
+ /*
+ * We have reached the maximum allowed PLL1 output,
+ * increase sysdiv.
+ */
+ if (rate == 0) {
+ _pll_mult = OV5640_PLL_MULT_MAX + 1;
+ continue;
+ }
+
if (abs(rate - _rate) < abs(rate - best)) {
best = _rate;
best_sysdiv = _sysdiv;
--
2.7.4
