linux-kernel - Re: [PATCH 04/11] net: phylink: switch to using fwnode_gpiod_get

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Message-ID: <20190911101016.GW13294@shell.armlinux.org.uk>
Date:   Wed, 11 Sep 2019 11:10:16 +0100
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
        Andrew Lunn <andrew@...n.ch>,
        "David S. Miller" <davem@...emloft.net>,
        Florian Fainelli <f.fainelli@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>, netdev@...r.kernel.org
Subject: Re: [PATCH 04/11] net: phylink: switch to using
 fwnode_gpiod_get_index()

On Wed, Sep 11, 2019 at 02:55:11AM -0700, Dmitry Torokhov wrote:
> On Wed, Sep 11, 2019 at 10:49:29AM +0100, Russell King - ARM Linux admin wrote:
> > On Wed, Sep 11, 2019 at 12:46:19PM +0300, Andy Shevchenko wrote:
> > > On Wed, Sep 11, 2019 at 10:39:14AM +0100, Russell King - ARM Linux admin wrote:
> > > > On Wed, Sep 11, 2019 at 12:25:14PM +0300, Andy Shevchenko wrote:
> > > > > On Wed, Sep 11, 2019 at 12:52:08AM -0700, Dmitry Torokhov wrote:
> > > > > > Instead of fwnode_get_named_gpiod() that I plan to hide away, let's use
> > > > > > the new fwnode_gpiod_get_index() that mimics gpiod_get_index(), bit
> > > > > > works with arbitrary firmware node.
> > e > > 
> > > > > I'm wondering if it's possible to step forward and replace
> > > > > fwnode_get_gpiod_index by gpiod_get() / gpiod_get_index() here and
> > > > > in other cases in this series.
> > > > 
> > > > No, those require a struct device, but we have none.  There are network
> > > > drivers where there is a struct device for the network complex, but only
> > > > DT nodes for the individual network interfaces.  So no, gpiod_* really
> > > > doesn't work.
> > > 
> > > In the following patch the node is derived from struct device. So, I believe
> > > some cases can be handled differently.
> > 
> > phylink is not passed a struct device - it has no knowledge what the
> > parent device is.
> > 
> > In any case, I do not have "the following patch".
> 
> Andy is talking about this one:
> 
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index ce940871331e..9ca51d678123 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -46,8 +46,8 @@ static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
> 
>         /* Deassert the optional reset signal */
>         if (mdiodev->dev.of_node)
> -               gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
> -                                              "reset-gpios", 0,
>                                                GPIOD_OUT_LOW,
> +               gpiod = fwnode_gpiod_get_index(&mdiodev->dev.of_node->fwnode,
> +                                              "reset", 0, GPIOD_OUT_LOW,
>                                                "PHY reset");
> Here if we do not care about "PHY reset" label, we could use
> gpiod_get(&mdiodev->dev, "reset", GPIOD_OUT_LOW).

Here, you have a struct device, so yes, it's possible.

Referring back to my comment, notice that I said we have none for the
phylink case, so it's not possible there.

I'm not sure why Andy replied the way he did, unless he mis-read my
comment.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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