Re: [PATCH v3 3/7] rng: stm32: Implement configurable RNG clock error detection

[Patrice CHOTARD <patrice.chotard@foss.st.com>]

On 9/19/23 17:27, 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@foss.st.com>
> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
> ---
> Changes in V2:
> 	- Added Patrick's tag
> 
>  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");
> +
>  	return 0;
>  }
>  
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

Thanks
Patrice