* [PATCH v3 1/1] media: i2c: imx219: add 1% tolerance on clock frequency
@ 2020-12-22 9:32 michael.srba
2021-02-02 22:55 ` Sakari Ailus
0 siblings, 1 reply; 2+ messages in thread
From: michael.srba @ 2020-12-22 9:32 UTC (permalink / raw)
To: Dave Stevenson, Mauro Carvalho Chehab; +Cc: linux-media, Michael Srba
From: Michael Srba <Michael.Srba@seznam.cz>
This patch adds 1% tolerance on input clock frequency, similar to other
camera sensor drivers.
Signed-off-by: Michael Srba <Michael.Srba@seznam.cz>
---
changes since v1: default to exactly 24MHz when `clock-frequency` is not
present
changes since v2: remove the ability to set the clock to a specific
frequency, since assigned-clocks + assigned-clock-rates can be used 1:1
for the same purpose
---
drivers/media/i2c/imx219.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
index f64c0ef7a897..fd2157eadac4 100644
--- a/drivers/media/i2c/imx219.c
+++ b/drivers/media/i2c/imx219.c
@@ -1443,8 +1443,9 @@ static int imx219_probe(struct i2c_client *client)
return PTR_ERR(imx219->xclk);
}
+ /* this driver currently expects 24MHz; allow 1% tolerance */
imx219->xclk_freq = clk_get_rate(imx219->xclk);
- if (imx219->xclk_freq != IMX219_XCLK_FREQ) {
+ if (imx219->xclk_freq < 23760000 || imx219->xclk_freq > 24240000) {
dev_err(dev, "xclk frequency not supported: %d Hz\n",
imx219->xclk_freq);
return -EINVAL;
--
2.29.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v3 1/1] media: i2c: imx219: add 1% tolerance on clock frequency
2020-12-22 9:32 [PATCH v3 1/1] media: i2c: imx219: add 1% tolerance on clock frequency michael.srba
@ 2021-02-02 22:55 ` Sakari Ailus
0 siblings, 0 replies; 2+ messages in thread
From: Sakari Ailus @ 2021-02-02 22:55 UTC (permalink / raw)
To: michael.srba
Cc: Dave Stevenson, Mauro Carvalho Chehab, linux-media, Laurent Pinchart
Hi Michael,
On Tue, Dec 22, 2020 at 10:32:31AM +0100, michael.srba@seznam.cz wrote:
> From: Michael Srba <Michael.Srba@seznam.cz>
>
> This patch adds 1% tolerance on input clock frequency, similar to other
> camera sensor drivers.
>
> Signed-off-by: Michael Srba <Michael.Srba@seznam.cz>
>
> ---
>
> changes since v1: default to exactly 24MHz when `clock-frequency` is not
> present
> changes since v2: remove the ability to set the clock to a specific
> frequency, since assigned-clocks + assigned-clock-rates can be used 1:1
> for the same purpose
>
> ---
> drivers/media/i2c/imx219.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> index f64c0ef7a897..fd2157eadac4 100644
> --- a/drivers/media/i2c/imx219.c
> +++ b/drivers/media/i2c/imx219.c
> @@ -1443,8 +1443,9 @@ static int imx219_probe(struct i2c_client *client)
> return PTR_ERR(imx219->xclk);
> }
>
> + /* this driver currently expects 24MHz; allow 1% tolerance */
> imx219->xclk_freq = clk_get_rate(imx219->xclk);
> - if (imx219->xclk_freq != IMX219_XCLK_FREQ) {
> + if (imx219->xclk_freq < 23760000 || imx219->xclk_freq > 24240000) {
Where do you need this? Do you have a system where you get a frequency
that's a bit off?
I don't think this is the right way to fix this but on the other hand for
register list based drivers there hardly is one.
> dev_err(dev, "xclk frequency not supported: %d Hz\n",
> imx219->xclk_freq);
> return -EINVAL;
--
Regards,
Sakari Ailus
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2020-12-22 9:32 [PATCH v3 1/1] media: i2c: imx219: add 1% tolerance on clock frequency michael.srba
2021-02-02 22:55 ` Sakari Ailus
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