[PATCH 3/7] rng: stm32: Implement configurable RNG clock error detection

[Patrick DELAUNAY]

Hi,

On 9/8/23 21:07, Heinrich Schuchardt wrote:
> On 9/7/23 18:21, Gatien Chevallier wrote:
>> RNG clock error detection is now enabled if the "clock-error-detect"
>> property is set in the device tree.
>>
>> Signed-off-by: Gatien Chevallier <gatien.chevallier at foss.st.com>
>> ---
>>   drivers/rng/stm32_rng.c | 22 +++++++++++++++++-----
>>   1 file changed, 17 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/rng/stm32_rng.c b/drivers/rng/stm32_rng.c
>> index 89da78c6c8..ada5d92214 100644
>> --- a/drivers/rng/stm32_rng.c
>> +++ b/drivers/rng/stm32_rng.c
>> @@ -40,6 +40,7 @@ struct stm32_rng_plat {
>>       struct clk clk;
>>       struct reset_ctl rst;
>>       const struct stm32_rng_data *data;
>> +    bool ced;
>>   };
>>
>>   static int stm32_rng_read(struct udevice *dev, void *data, size_t len)
>> @@ -97,25 +98,34 @@ static int stm32_rng_init(struct stm32_rng_plat 
>> *pdata)
>>
>>       cr = readl(pdata->base + RNG_CR);
>>
>> -    /* Disable CED */
>> -    cr |= RNG_CR_CED;
>>       if (pdata->data->has_cond_reset) {
>>           cr |= RNG_CR_CONDRST;
>> +        if (pdata->ced)
>> +            cr &= ~RNG_CR_CED;
>> +        else
>> +            cr |= RNG_CR_CED;
>>           writel(cr, pdata->base + RNG_CR);
>>           cr &= ~RNG_CR_CONDRST;
>> +        cr |= RNG_CR_RNGEN;
>>           writel(cr, pdata->base + RNG_CR);
>>           err = readl_poll_timeout(pdata->base + RNG_CR, cr,
>>                        (!(cr & RNG_CR_CONDRST)), 10000);
>>           if (err)
>>               return err;
>> +    } else {
>> +        if (pdata->ced)
>> +            cr &= ~RNG_CR_CED;
>> +        else
>> +            cr |= RNG_CR_CED;
>> +
>> +        cr |= RNG_CR_RNGEN;
>> +
>> +        writel(cr, pdata->base + RNG_CR);
>>       }
>>
>>       /* clear error indicators */
>>       writel(0, pdata->base + RNG_SR);
>>
>> -    cr |= RNG_CR_RNGEN;
>> -    writel(cr, pdata->base + RNG_CR);
>> -
>>       err = readl_poll_timeout(pdata->base + RNG_SR, sr,
>>                    sr & RNG_SR_DRDY, 10000);
>>       return err;
>> @@ -165,6 +175,8 @@ static int stm32_rng_of_to_plat(struct udevice *dev)
>>       if (err)
>>           return err;
>>
>> +    pdata->ced = dev_read_bool(dev, "clock-error-detect");
>
> The kernel describes this property in
> Documentation/devicetree/bindings/rng/st,stm32-rng.yaml
>
> Which patch is adding it to the U-Boot device-trees?
> I can't find it in this patch series.


For STM32 platform we rely on the bindin files of kernel to avoid to 
duplicate the binding after yaml migration

and we add the U-Boot specificity only when it is needed (for clock and ram)


See Documentation: 
https://u-boot.readthedocs.io/en/stable/board/st/st-dt.html

doc/board/st/st-dt.rst

* rng
     - rng/st,stm32-rng.yaml


So for me no need of binding patch in U-Boot since [1] as this property 
is already supported by kernel binding.

[1] 551a959a8c11 ("doc: stm32mp1: add page for device tree bindings")

http://patchwork.ozlabs.org/project/uboot/patch/20210802180823.1.I3aa79d907e5213c8692d2d428f5a1fbccdce555b@changeid/


Patrick


>
> It would have been helpful to send a cover-letter with the patch series
> to get an overview of the changed files in the patch set.
>
> Best regards
>
> Heinrich
>
>> +
>>       return 0;
>>   }
>>
>