[PATCH 1/1] video: avoid build failure on veyron board

[Kever Yang]

On 2023/8/4 08:35, Alvaro Fernando García wrote:
> 533ad9dc avoided an overflow but causes compilation
> failure on 32bit boards (eg. veyron speedy)
>
> this commit uses div_u64 which has a fallback codepath
> for 32bit platforms
>
> Signed-off-by: Alvaro Fernando García <alvarofernandogarcia at gmail.com>

Reviewed-by: Kever Yang <kever.yang at rock-chips.com>

Thanks,
- Kever
> ---
>
>   drivers/video/pwm_backlight.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/video/pwm_backlight.c b/drivers/video/pwm_backlight.c
> index 46c16a8f44..aa0e292866 100644
> --- a/drivers/video/pwm_backlight.c
> +++ b/drivers/video/pwm_backlight.c
> @@ -14,6 +14,7 @@
>   #include <pwm.h>
>   #include <asm/gpio.h>
>   #include <linux/delay.h>
> +#include <linux/math64.h>
>   #include <power/regulator.h>
>   
>   /**
> @@ -59,12 +60,14 @@ struct pwm_backlight_priv {
>   
>   static int set_pwm(struct pwm_backlight_priv *priv)
>   {
> +	u64 width;
>   	uint duty_cycle;
>   	int ret;
>   
>   	if (priv->period_ns) {
> -		duty_cycle = (u64)priv->period_ns * (priv->cur_level - priv->min_level) /
> -			(priv->max_level - priv->min_level);
> +		width = priv->period_ns * (priv->cur_level - priv->min_level);
> +		duty_cycle = div_u64(width,
> +				     (priv->max_level - priv->min_level));
>   		ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
>   				     duty_cycle);
>   	} else {