Subject: Re: [PATCH v2 1/2] clk: st: clkgen-fsyn: search reg within node or
 parent
To:     Alain Volmat <avolmat@me.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Rob Herring <robh+dt@kernel.org>
CC:     Lee Jones <lee.jones@linaro.org>, <linux-clk@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>
References: <20211218211157.188214-1-avolmat@me.com>
 <20211218211157.188214-2-avolmat@me.com>
From:   Patrice CHOTARD <patrice.chotard@foss.st.com>
Message-ID: <b7b31539-3752-a566-75b9-e94659d21c31@foss.st.com>
Date:   Mon, 20 Dec 2021 09:42:15 +0100
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Hi Alain

On 12/18/21 10:11 PM, Alain Volmat wrote:
> In order to avoid having duplicated addresses within the DT,
> only have one unit-address per clockgen and each driver within
> the clockgen should look at the parent node (overall clockgen)
> to figure out the reg property.  Such behavior is already in
> place in other STi platform clock drivers such as clk-flexgen
> and clkgen-pll.  Keep backward compatibility by first looking
> at reg within the node before looking into the parent node.
> 
> Signed-off-by: Alain Volmat <avolmat@me.com>
> ---
> v2: add pr_err message when failing to get reg information
> 
>  drivers/clk/st/clkgen-fsyn.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/st/clkgen-fsyn.c b/drivers/clk/st/clkgen-fsyn.c
> index 164285d6be97..582a22c04919 100644
> --- a/drivers/clk/st/clkgen-fsyn.c
> +++ b/drivers/clk/st/clkgen-fsyn.c
> @@ -988,9 +988,18 @@ static void __init st_of_quadfs_setup(struct device_node *np,
>  	void __iomem *reg;
>  	spinlock_t *lock;
>  
> +	/*
> +	 * First check for reg property within the node to keep backward
> +	 * compatibility, then if reg doesn't exist look at the parent node
> +	 */
>  	reg = of_iomap(np, 0);
> -	if (!reg)
> -		return;
> +	if (!reg) {
> +		reg = of_iomap(of_get_parent(np), 0);
> +		if (!reg) {
> +			pr_err("%s: Failed to get base address\n", __func__);
> +			return;
> +		}
> +	}
>  
>  	clk_parent_name = of_clk_get_parent_name(np, 0);
>  	if (!clk_parent_name)
> 
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

THanks
Patrice