linux-kernel - Re: [PATCH] clk: imx: gate2: Fix the is

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Message-ID: <20201028082412.GU26805@pengutronix.de>
Date:   Wed, 28 Oct 2020 09:24:12 +0100
From:   Sascha Hauer <s.hauer@...gutronix.de>
To:     Abel Vesa <abel.vesa@....com>
Cc:     Mike Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, Rob Herring <robh@...nel.org>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <kernel@...gutronix.de>,
        Fabio Estevam <fabio.estevam@....com>,
        Anson Huang <anson.huang@....com>,
        Jacky Bai <ping.bai@....com>, Peng Fan <peng.fan@....com>,
        Dong Aisheng <aisheng.dong@....com>, linux-clk@...r.kernel.org,
        NXP Linux Team <linux-imx@....com>,
        linux-arm-kernel@...ts.infradead.org,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] clk: imx: gate2: Fix the is_enabled op

Hi Abel,

On Mon, Oct 26, 2020 at 08:50:48PM +0200, Abel Vesa wrote:
> The clock is considered to be enabled only if the controlling bits
> match the cgr_val mask. Also make sure the is_enabled returns the
> correct vaule by locking the access to the register.
> 
> Signed-off-by: Abel Vesa <abel.vesa@....com>
> Fixes: 1e54afe9fcfe ("clk: imx: gate2: Allow single bit gating clock")
> ---
>  drivers/clk/imx/clk-gate2.c | 60 ++++++++++++++++++++-------------------------
>  drivers/clk/imx/clk.h       |  8 ++----
>  2 files changed, 29 insertions(+), 39 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-gate2.c b/drivers/clk/imx/clk-gate2.c
> index 7eed708..f320bd2b 100644
> --- a/drivers/clk/imx/clk-gate2.c
> +++ b/drivers/clk/imx/clk-gate2.c
> @@ -37,10 +37,22 @@ struct clk_gate2 {
>  
>  #define to_clk_gate2(_hw) container_of(_hw, struct clk_gate2, hw)
>  
> +static void clk_gate2_do_shared_clks(struct clk_hw *hw, bool enable)
> +{
> +	struct clk_gate2 *gate = to_clk_gate2(hw);
> +	u32 reg;
> +
> +	reg = readl(gate->reg);
> +	if (enable)
> +		reg |= gate->cgr_val << gate->bit_idx;
> +	else
> +		reg &= ~(gate->cgr_val << gate->bit_idx);

Shouldn't this be:

	reg &= ~(3 << gate->bit_idx);
	if (enable)
		reg |= gate->cgr_val << gate->bit_idx;

At least that's how it was without this patch and that's how it makes
sense to me with cgr_val != 3.

Sascha


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