Re: [PATCH] clocksource: rtl-otto: Change driver to use __raw reads and writes

[Rustam Adilov]

On 2026-05-11 13:15, Rustam Adilov wrote:
> As it stands, the driver uses ioread32 and iowrite32 for register
> access and it works fine. However this stops working when the
> SWAP_IO_SPACE config is enabled as this drivers expects ioread32 and
> iowrite32 to be in native endian (that is big endian for currently
> supported SoCs). RTL9607C is a big endian MIPS SoC that has identical
> timer as the already supported chips but needs to have SWAP_IO_SPACE
> to have a functioning little endian USB host.
> 
> Fix this by replacing all instances of ioread32 and iowrite32 with
> __raw_readl and __raw_writel variants. Since they essentially do
> the same register access, this shouldn't affect anything on other
> machines.
> 
> Signed-off-by: Rustam Adilov <adilov@xxxxxxxxxxx>
> ---
>  drivers/clocksource/timer-rtl-otto.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/clocksource/timer-rtl-otto.c b/drivers/clocksource/timer-rtl-otto.c
> index 6113d2fdd4de..bcb449ef0481 100644
> --- a/drivers/clocksource/timer-rtl-otto.c
> +++ b/drivers/clocksource/timer-rtl-otto.c
> @@ -56,37 +56,37 @@ struct rttm_cs {
>  /* Simple internal register functions */
>  static inline unsigned int rttm_get_counter(void __iomem *base)
>  {
> -	return ioread32(base + RTTM_CNT);
> +	return __raw_readl(base + RTTM_CNT);
>  }
>  
>  static inline void rttm_set_period(void __iomem *base, unsigned int period)
>  {
> -	iowrite32(period, base + RTTM_DATA);
> +	__raw_writel(period, base + RTTM_DATA);
>  }
>  
>  static inline void rttm_disable_timer(void __iomem *base)
>  {
> -	iowrite32(0, base + RTTM_CTRL);
> +	__raw_writel(0, base + RTTM_CTRL);
>  }
>  
>  static inline void rttm_enable_timer(void __iomem *base, u32 mode, u32 divisor)
>  {
> -	iowrite32(RTTM_CTRL_ENABLE | mode | divisor, base + RTTM_CTRL);
> +	__raw_writel(RTTM_CTRL_ENABLE | mode | divisor, base + RTTM_CTRL);
>  }
>  
>  static inline void rttm_ack_irq(void __iomem *base)
>  {
> -	iowrite32(ioread32(base + RTTM_INT) | RTTM_INT_PENDING, base + RTTM_INT);
> +	__raw_writel(__raw_readl(base + RTTM_INT) | RTTM_INT_PENDING, base + RTTM_INT);
>  }
>  
>  static inline void rttm_enable_irq(void __iomem *base)
>  {
> -	iowrite32(RTTM_INT_ENABLE, base + RTTM_INT);
> +	__raw_writel(RTTM_INT_ENABLE, base + RTTM_INT);
>  }
>  
>  static inline void rttm_disable_irq(void __iomem *base)
>  {
> -	iowrite32(0, base + RTTM_INT);
> +	__raw_writel(0, base + RTTM_INT);
>  }
>  
>  /* Aggregated control functions for kernel clock framework */

It appears the get_maintainer.pl script didn't catch the Chris Packham, presumably
because i didn't touch the device bindings file. Added them to CC for review.