Re: [PATCH] reset: spacemit: Fix the RCPU2 PWM reset registers

[Yixun Lan <dlan@kernel.org>]

Hi Hung-Chun,

On 22:08 Sat 17 Oct     , Hung-Chun Tseng wrote:
> Every entry in k1_rcpu2_resets[] uses RCPU2_PWM9_CLK_RST, so asserting
> or deasserting the reset of any RCPU2 PWM from 0 to 8 acts on PWM9
> instead. Each PWM has its own register, RCPU2_PWMn_CLK_RST at offset
> 4 * n, as k1-syscon.h already defines.
> 
> On a Milk-V Jupiter running the vendor kernel, which uses RCPU2 PWM2
> for the fan, the RCPU2 registers read:
> 
>   0x00: 0x4  0x04: 0x4  0x08: 0x1  0x0c: 0x4  ...  0x24: 0x4
> 
> Only PWM2's register has its reset deasserted, which matches one
> register per PWM.
> 
Also match vendor's code, see
https://gitee.com/spacemit-buildroot/linux-6.6/blob/k1-bl-v2.2.y/drivers/reset/reset-spacemit-k1x.c#L317

> Use the matching register for each reset. No in-tree device tree uses
> the RCPU2 PWMs yet, so this has no effect on current boards, but it
> would break the first one that does.
> 
> Build-tested only (riscv defconfig, W=1); the fix could not be tested
> at runtime, as mainline has no RCPU2 PWM node to exercise it.
> 
> Fixes: c479d7cf06c3 ("reset: spacemit: add support for SpacemiT CCU resets")
> Assisted-by: claude-opus-5-5
> Signed-off-by: Hung-Chun Tseng <alan.tseng.cs@gmail.com>
> ---
>  drivers/reset/spacemit/reset-spacemit-k1.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
Reviewed-by: Yixun Lan <dlan@kernel.org>

> diff --git a/drivers/reset/spacemit/reset-spacemit-k1.c b/drivers/reset/spacemit/reset-spacemit-k1.c
> index 8f3b5329e..dbd783c13 100644
> --- a/drivers/reset/spacemit/reset-spacemit-k1.c
> +++ b/drivers/reset/spacemit/reset-spacemit-k1.c
> @@ -154,15 +154,15 @@ static const struct ccu_reset_controller_data k1_rcpu_reset_data = {
>  };
>  
>  static const struct ccu_reset_data k1_rcpu2_resets[] = {
> -	[RESET_RCPU2_PWM0]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM1]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM2]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM3]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM4]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM5]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM6]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM7]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> -	[RESET_RCPU2_PWM8]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM0]	= RESET_DATA(RCPU2_PWM0_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM1]	= RESET_DATA(RCPU2_PWM1_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM2]	= RESET_DATA(RCPU2_PWM2_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM3]	= RESET_DATA(RCPU2_PWM3_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM4]	= RESET_DATA(RCPU2_PWM4_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM5]	= RESET_DATA(RCPU2_PWM5_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM6]	= RESET_DATA(RCPU2_PWM6_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM7]	= RESET_DATA(RCPU2_PWM7_CLK_RST, BIT(2), BIT(0)),
> +	[RESET_RCPU2_PWM8]	= RESET_DATA(RCPU2_PWM8_CLK_RST, BIT(2), BIT(0)),
>  	[RESET_RCPU2_PWM9]	= RESET_DATA(RCPU2_PWM9_CLK_RST, BIT(2), BIT(0)),
>  };
>  
> -- 
> 2.43.0
> 

-- 
Yixun Lan (dlan)