Hello!
On 12/08/2017 12:53 PM, Geert Uytterhoeven wrote:
On 12/04/2017 03:35 PM, Geert Uytterhoeven wrote:
From: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
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 -- it made use of the reset GPIO for its own purposes...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
[geert: Propagate actual errors from fwnode_get_named_gpiod()]
[geert: Avoid destroying initial setup]
[geert: Consolidate GPIO descriptor acquiring code]
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
[...]
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 2df7b62c1a36811e..8f8b7747c54bc478 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
[...]
@@ -48,9 +49,26 @@
int mdiobus_register_device(struct mdio_device *mdiodev)
{
+ struct gpio_desc *gpiod = NULL;
+
if (mdiodev->bus->mdio_map[mdiodev->addr])
return -EBUSY;
+ /* Deassert the optional reset signal */
Umm, but why deassert it here for such a short time?
That's a consequence of moving it from drivers/of/of_mdio.c to here.
Well, you shouldn't do code moves without some thinking. ;-)
Not that it was deasserted that much longer in drivers/of/of_mdio.c, though...
There it had a reason, here I'm not seeing one. Perhaps using GPIOD_ASIS
(or GPIOD_OUT_HIGH) instead of GPIOD_OUT_LOW and dropping
mdio_device_reset(mdiodev, 1) afterwards would make more sense here?
Gr{oetje,eeting}s,
Geert
MBR, Sergei
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