linux-kernel - Re: [PATCH v6 03/10] clk: of-provider: look at parent if registered device has no provider info

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: <154395229720.88331.16585219136189943316@swboyd.mtv.corp.google.com>
Date:   Tue, 04 Dec 2018 11:38:17 -0800
From:   Stephen Boyd <sboyd@...nel.org>
To:     matti.vaittinen@...rohmeurope.com, mazziesaccount@...il.com
Cc:     mturquette@...libre.com, cw00.choi@...sung.com, krzk@...nel.org,
        b.zolnierkie@...sung.com, linux@...linux.org.uk,
        andy.gross@...aro.org, david.brown@...aro.org, pavel@....cz,
        andrew.smirnov@...il.com, pombredanne@...b.com,
        sjhuang@...vatar.ai, akshu.agrawal@....com, djkurtz@...omium.org,
        rafael.j.wysocki@...el.com, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v6 03/10] clk: of-provider: look at parent if registered device
 has no provider info

Quoting Matti Vaittinen (2018-12-04 03:34:53)
> It seems to be usual for MFD devices that the created 'clock sub-device'
> do not have own DT node. The clock provider information is usually in the
> main device node which is owned by the MFD device. Change the devm variant
> of clk of-provider registration to check the parent device node if given
> device has no own node or if the node does not contain the #clock-cells
> property. In such case use the parent node if it contains the #clock-cells.
> 
> Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
> ---
>  drivers/clk/clk.c | 27 +++++++++++++++++++++++----
>  1 file changed, 23 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 78c90913f987..66dc7c1483d7 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3893,6 +3893,11 @@ static void devm_of_clk_release_provider(struct device *dev, void *res)
>         of_clk_del_provider(*(struct device_node **)res);
>  }
>  
> +static int of_is_clk_provider(struct device_node *np)
> +{
> +       return !!of_find_property(np, "#clock-cells", NULL);
> +}
> +
>  /**
>   * devm_of_clk_add_hw_provider() - Managed clk provider node registration
>   * @dev: Device acting as the clock provider. Used for DT node and lifetime.
> @@ -3901,8 +3906,11 @@ static void devm_of_clk_release_provider(struct device *dev, void *res)
>   *
>   * Returns 0 on success or an errno on failure.
>   *
> - * Registers clock provider for given device's node. Provider is automatically
> - * released at device exit.
> + * Registers clock provider for given device's node. If the device has no DT
> + * node or if the device node lacks of clock provider information (#clock-cells)
> + * then the parent device's node is scanned for this information. If parent node
> + * has the #clock-cells then it is used in registration. Provider is
> + * automatically released at device exit.
>   */
>  int devm_of_clk_add_hw_provider(struct device *dev,
>                         struct clk_hw *(*get)(struct of_phandle_args *clkspec,
> @@ -3912,12 +3920,17 @@ int devm_of_clk_add_hw_provider(struct device *dev,
>         struct device_node **ptr, *np;
>         int ret;
>  
> +       np = dev->of_node;
> +
> +       if (!of_is_clk_provider(dev->of_node))
> +               if (of_is_clk_provider(dev->parent->of_node))
> +                       np = dev->parent->of_node;

As said on v5, let's just modify of_clk_add_provider() to do the parent
search.