Re: [PATCH] clocksource: sh_cmt: use CMTOUT_IE only when supported

["Niklas Söderlund" <niklas.soderlund@ragnatech.se>]

Hi Wolfram,

Thanks for your patch.

On 2021-03-05 14:28:59 +0100, Wolfram Sang wrote:
> CMTOUT_IE is only supported for older SoCs. Newer SoCs shall not set
> this bit. So, add a version check.
> 
> Reported-by: Phong Hoang <phong.hoang.wz@renesas.com>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> ---
> 
> Confirmed with datasheets and could successfully repeat Niklas' CMT
> tests on an R-Car M3N based Salvator-XS.
> 
>  drivers/clocksource/sh_cmt.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
> index c98f8851fd68..3b53c6cb1da9 100644
> --- a/drivers/clocksource/sh_cmt.c
> +++ b/drivers/clocksource/sh_cmt.c
> @@ -143,6 +143,7 @@ struct sh_cmt_device {
>  #define SH_CMT32_CMCSR_SSIE		(1 << 10)
>  #define SH_CMT32_CMCSR_CMS		(1 << 9)
>  #define SH_CMT32_CMCSR_CMM		(1 << 8)
> +/* CMTOUT_IE only for SH_CMT_32BIT and SH_CMT_48BIT */
>  #define SH_CMT32_CMCSR_CMTOUT_IE	(1 << 7)
>  #define SH_CMT32_CMCSR_CMR_NONE		(0 << 4)
>  #define SH_CMT32_CMCSR_CMR_DMA		(1 << 4)
> @@ -339,8 +340,9 @@ static int sh_cmt_enable(struct sh_cmt_channel *ch)
>  		sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE |
>  				   SH_CMT16_CMCSR_CKS512);
>  	} else {
> -		sh_cmt_write_cmcsr(ch, SH_CMT32_CMCSR_CMM |
> -				   SH_CMT32_CMCSR_CMTOUT_IE |
> +		u32 cmtout = ch->cmt->info->model <= SH_CMT_48BIT ?
> +			      SH_CMT32_CMCSR_CMTOUT_IE : 0;
> +		sh_cmt_write_cmcsr(ch, cmtout | SH_CMT32_CMCSR_CMM |
>  				   SH_CMT32_CMCSR_CMR_IRQ |
>  				   SH_CMT32_CMCSR_CKS_RCLK8);
>  	}
> -- 
> 2.29.2
> 

-- 
Regards,
Niklas Söderlund