Re: [PATCH v4 5/8] reset: starfive: Introduce active_low

From: Conor Dooley <conor@kernel.org>
To: Changhuang Liang <changhuang.liang@starfivetech.com>
Cc: Michael Turquette <mturquette@baylibre.com>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Stephen Boyd <sboyd@kernel.org>,
	Brian Masney <bmasney@redhat.com>, Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Emil Renner Berthing <kernel@esmil.dk>,
	Chen Wang <unicorn_wang@outlook.com>,
	Inochi Amaoto <inochiama@gmail.com>,
	Alexey Charkov <alchark@gmail.com>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Keguang Zhang <keguang.zhang@gmail.com>,
	linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, linux-riscv@lists.infradead.org
Subject: Re: [PATCH v4 5/8] reset: starfive: Introduce active_low
Date: Mon, 10 Aug 2026 17:22:03 +0100	[thread overview]
Message-ID: <20260810-overhead-seventy-cdab37ccb66d@spud> (raw)
In-Reply-To: <20260809015054.210577-6-changhuang.liang@starfivetech.com>

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On Sat, Aug 08, 2026 at 06:50:51PM -0700, Changhuang Liang wrote:
> The JHB100 SoC supports inverted operations for reset
> assertion/deassertion, introducing an active_low field to distinguish
> between different operation logics.
> 
> Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>

Can you please get Hal to review this and the other reset patch?

Thanks,
Conor.

> ---
>  drivers/reset/starfive/reset-starfive-common.c | 6 +++++-
>  drivers/reset/starfive/reset-starfive-common.h | 6 ++++++
>  2 files changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/reset/starfive/reset-starfive-common.c b/drivers/reset/starfive/reset-starfive-common.c
> index 86dbb33bb216..7723520637ca 100644
> --- a/drivers/reset/starfive/reset-starfive-common.c
> +++ b/drivers/reset/starfive/reset-starfive-common.c
> @@ -52,12 +52,16 @@ static int starfive_reset_update(struct reset_controller_dev *rcdev,
>  				 unsigned long id, bool assert)
>  {
>  	struct starfive_reset *data = starfive_reset_from(rcdev);
> +	bool active_low = data->info && data->info->active_low;
>  	unsigned long offset, flags;
>  	void __iomem *reg_assert;
>  	void __iomem *reg_status;
>  	u32 mask, done, value;
>  	int ret;
>  
> +	if (active_low)
> +		assert = !assert;
> +
>  	if (data->info && data->info->discontiguous) {
>  		id = starfive_reset_id_to_hw_id(data->info->map, data->info->nr_resets, id);
>  		if (id == STARFIVE_RESET_ID_INVALID)
> @@ -70,7 +74,7 @@ static int starfive_reset_update(struct reset_controller_dev *rcdev,
>  	reg_status = data->status + offset * sizeof(u32);
>  	done = data->asserted ? data->asserted[offset] & mask : 0;
>  
> -	if (!assert)
> +	if (active_low == assert)
>  		done ^= mask;
>  
>  	spin_lock_irqsave(&data->lock, flags);
> diff --git a/drivers/reset/starfive/reset-starfive-common.h b/drivers/reset/starfive/reset-starfive-common.h
> index 0d4e634de58e..c7f80e744700 100644
> --- a/drivers/reset/starfive/reset-starfive-common.h
> +++ b/drivers/reset/starfive/reset-starfive-common.h
> @@ -15,6 +15,12 @@ struct starfive_reset_info {
>  	unsigned int nr_resets;
>  	unsigned int assert_offset;
>  	unsigned int status_offset;
> +
> +	/* If active_low is false, setting the bit to 1 asserts
> +	 * the signal while clearing it to 0 deasserts it, and vice
> +	 * versa.
> +	 */
> +	bool active_low;
>  	bool discontiguous;
>  	const struct starfive_reset_map *map;
>  };
> -- 
> 2.25.1
> 

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