Re: [PATCH RFT 1/2] phylib: add device reset GPIO support

[Sergei Shtylyov]

On 04/11/2016 10:25 PM, Rob Herring wrote:

> > The PHY  devices sometimes do have their reset signal (maybe even power
> > supply?) tied to some GPIO and sometimes it also does happen that a boot
> > loader does not leave it deasserted. So far this issue has been attacked
> > from (as I believe) a wrong angle: by teaching the MAC driver to manipulate
> > the GPIO in question;  that solution, when  applied to the device trees,
> > led to adding the PHY reset GPIO properties to the MAC device node, with
> > one exception: Cadence MACB driver which could handle the "reset-gpios"
> > prop  in a PHY device  subnode.  I believe that the correct approach is to
> > teach the 'phylib' to get the MDIO device reset GPIO from the device tree
> > node corresponding to this device -- which this patch is doing...
> >
> > Note that I had to modify the  AT803x PHY driver as it would stop working
> > otherwise as it made use of the reset GPIO for its own purposes...
>
> Lots of double spaces in here. Please fix.

   Oh, it's you again! :-D

> > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
> >
> > ---
> >   Documentation/devicetree/bindings/net/phy.txt |    2 +
> >   drivers/net/phy/at803x.c                      |   19 ++------------
> >   drivers/net/phy/mdio_bus.c                    |    4 +++
> >   drivers/net/phy/mdio_device.c                 |   27 +++++++++++++++++++--
> >   drivers/net/phy/phy_device.c                  |   33 ++++++++++++++++++++++++--
> >   drivers/of/of_mdio.c                          |   16 ++++++++++++
> >   include/linux/mdio.h                          |    3 ++
> >   include/linux/phy.h                           |    5 +++
> >   8 files changed, 89 insertions(+), 20 deletions(-)
>
> [...]
>
> > Index: net-next/drivers/of/of_mdio.c
> > ===================================================================
> > --- net-next.orig/drivers/of/of_mdio.c
> > +++ net-next/drivers/of/of_mdio.c
> > @@ -44,6 +44,7 @@ static int of_get_phy_id(struct device_n
> >   static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *child,
> >   				   u32 addr)
> >   {
> > +	struct gpio_desc *gpiod;
> >   	struct phy_device *phy;
> >   	bool is_c45;
> >   	int rc;
> > @@ -52,10 +53,17 @@ static int of_mdiobus_register_phy(struc
> >   	is_c45 = of_device_is_compatible(child,
> >   					 "ethernet-phy-ieee802.3-c45");
> >
> > +	gpiod = fwnode_get_named_gpiod(&child->fwnode, "reset-gpios");
>
> Calling fwnode_* functions in a DT specific file/function? That doesn't
> make sense.

   Really?! 8-)
   Where is a DT-only analog I wonder...

MBR, Sergei