linux-kernel - Re: [PATCH v2 5/5] clk: amlogic: Change the active level of l

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1j4irgzss4.fsf@starbuckisacylon.baylibre.com>
Date: Thu, 30 Oct 2025 09:40:43 +0100
From: Jerome Brunet <jbrunet@...libre.com>
To: Chuan Liu via B4 Relay <devnull+chuan.liu.amlogic.com@...nel.org>
Cc: Neil Armstrong <neil.armstrong@...aro.org>,  Michael Turquette
 <mturquette@...libre.com>,  Stephen Boyd <sboyd@...nel.org>,  Kevin Hilman
 <khilman@...libre.com>,  Martin Blumenstingl
 <martin.blumenstingl@...glemail.com>,  chuan.liu@...ogic.com,
  linux-amlogic@...ts.infradead.org,  linux-clk@...r.kernel.org,
  linux-arm-kernel@...ts.infradead.org,  linux-kernel@...r.kernel.org,
  da@...re.computer
Subject: Re: [PATCH v2 5/5] clk: amlogic: Change the active level of l_detect

On Thu 30 Oct 2025 at 13:24, Chuan Liu via B4 Relay <devnull+chuan.liu.amlogic.com@...nel.org> wrote:

> From: Chuan Liu <chuan.liu@...ogic.com>
>
> l_detect controls the enable/disable of the PLL lock-detect module.
>
> The enable signal is normally active-high. This design ensures that
> the module remains disabled during the power-on process, preventing
> power fluctuations from affecting its operating state.
>
> For A1, the l_detect signal is active-low:
> 0 -> Enable lock-detect module;
> 1 -> Disable lock-detect module.
>
> Here, a flag CLK_MESON_PLL_L_DETECT_N is added to handle cases like
> A1, where the signal is active-low.

Given that A1 is the only ship supporting l_detect, this change is not
necessary.

Not now at least.

>
> Signed-off-by: Chuan Liu <chuan.liu@...ogic.com>
> ---
>  drivers/clk/meson/a1-pll.c  |  1 +
>  drivers/clk/meson/clk-pll.c | 16 ++++++++++++----
>  drivers/clk/meson/clk-pll.h |  2 ++
>  3 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/clk/meson/a1-pll.c b/drivers/clk/meson/a1-pll.c
> index 1f82e9c7c14e..bfe559c71402 100644
> --- a/drivers/clk/meson/a1-pll.c
> +++ b/drivers/clk/meson/a1-pll.c
> @@ -137,6 +137,7 @@ static struct clk_regmap a1_hifi_pll = {
>  		.range = &a1_hifi_pll_range,
>  		.init_regs = a1_hifi_pll_init_regs,
>  		.init_count = ARRAY_SIZE(a1_hifi_pll_init_regs),
> +		.flags = CLK_MESON_PLL_L_DETECT_N
>  	},
>  	.hw.init = &(struct clk_init_data){
>  		.name = "hifi_pll",
> diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
> index c6eebde1f516..d729e933aa1c 100644
> --- a/drivers/clk/meson/clk-pll.c
> +++ b/drivers/clk/meson/clk-pll.c
> @@ -384,8 +384,12 @@ static int meson_clk_pll_enable(struct clk_hw *hw)
>  		meson_parm_write(clk->map, &pll->rst, 1);
>  
>  	/* Disable the PLL lock-detect module */
> -	if (MESON_PARM_APPLICABLE(&pll->l_detect))
> -		meson_parm_write(clk->map, &pll->l_detect, 1);
> +	if (MESON_PARM_APPLICABLE(&pll->l_detect)) {
> +		if (pll->flags & CLK_MESON_PLL_L_DETECT_N)
> +			meson_parm_write(clk->map, &pll->l_detect, 1);
> +		else
> +			meson_parm_write(clk->map, &pll->l_detect, 0);
> +	}
>  
>  	/* Enable the pll */
>  	meson_parm_write(clk->map, &pll->en, 1);
> @@ -413,8 +417,12 @@ static int meson_clk_pll_enable(struct clk_hw *hw)
>  	udelay(20);
>  
>  	/* Enable the lock-detect module */
> -	if (MESON_PARM_APPLICABLE(&pll->l_detect))
> -		meson_parm_write(clk->map, &pll->l_detect, 0);
> +	if (MESON_PARM_APPLICABLE(&pll->l_detect)) {
> +		if (pll->flags & CLK_MESON_PLL_L_DETECT_N)
> +			meson_parm_write(clk->map, &pll->l_detect, 0);
> +		else
> +			meson_parm_write(clk->map, &pll->l_detect, 1);
> +	}
>  
>  	if (meson_clk_pll_wait_lock(hw)) {
>  		/* disable PLL when PLL lock failed. */
> diff --git a/drivers/clk/meson/clk-pll.h b/drivers/clk/meson/clk-pll.h
> index 949157fb7bf5..83295a24721f 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-low */
> +#define CLK_MESON_PLL_L_DETECT_N	BIT(2)
>  
>  struct meson_clk_pll_data {
>  	struct parm en;

-- 
Jerome