Re: [PATCH 05/10] clk: amlogic: PLL l_detect signal supports active-high configuration

[Jerome Brunet <jbrunet@baylibre.com>]

On lun. 11 mai 2026 at 20:47, Jian Hu via B4 Relay <devnull+jian.hu.amlogic.com@kernel.org> wrote:

> From: Jian Hu <jian.hu@amlogic.com>
>
> l_detect controls the enable/disable of the PLL lock-detect module.
>
> For A9, the l_detect signal is active-high:
> 0 -> Disable lock-detect module;
> 1 -> Enable lock-detect module.
>
> Here, a flag CLK_MESON_PLL_L_DETECT_ACTIVE_HIGH is added to handle cases
> like A9, where the signal is active-high.
>
> Signed-off-by: Jian Hu <jian.hu@amlogic.com>
> ---
>  drivers/clk/meson/clk-pll.c | 9 +++++++--
>  drivers/clk/meson/clk-pll.h | 2 ++
>  2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
> index 1ea6579a760f..5a0bd75f85a9 100644
> --- a/drivers/clk/meson/clk-pll.c
> +++ b/drivers/clk/meson/clk-pll.c
> @@ -388,8 +388,13 @@ static int meson_clk_pll_enable(struct clk_hw *hw)
>  	}
>  
>  	if (MESON_PARM_APPLICABLE(&pll->l_detect)) {
> -		meson_parm_write(clk->map, &pll->l_detect, 1);
> -		meson_parm_write(clk->map, &pll->l_detect, 0);
> +		if (pll->flags & CLK_MESON_PLL_L_DETECT_ACTIVE_HIGH) {
> +			meson_parm_write(clk->map, &pll->l_detect, 0);
> +			meson_parm_write(clk->map, &pll->l_detect, 1);
> +		} else {
> +			meson_parm_write(clk->map, &pll->l_detect, 1);
> +			meson_parm_write(clk->map, &pll->l_detect, 0);
> +		}

I'm not a fan of this code duplication.
Use the introduced CLK_MESON_PLL_L_DETECT_ACTIVE_HIGH to compute the
first value, then flip the bit.

>  	}
>  
>  	if (meson_clk_pll_wait_lock(hw))
> diff --git a/drivers/clk/meson/clk-pll.h b/drivers/clk/meson/clk-pll.h
> index 949157fb7bf5..97b7c70376a3 100644
> --- a/drivers/clk/meson/clk-pll.h
> +++ b/drivers/clk/meson/clk-pll.h
> @@ -29,6 +29,8 @@ struct pll_mult_range {
>  
>  #define CLK_MESON_PLL_ROUND_CLOSEST	BIT(0)
>  #define CLK_MESON_PLL_NOINIT_ENABLED	BIT(1)
> +/* l_detect signal is active-high */
> +#define CLK_MESON_PLL_L_DETECT_ACTIVE_HIGH	BIT(2)
>  
>  struct meson_clk_pll_data {
>  	struct parm en;

-- 
Jerome