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2 Commits (8d65b08debc7e62b2c6032d7fe7389d895b92cbc)

Author SHA1 Message Date
Florian Fainelli 4c5e7a2c05 dt-bindings: mdio: Clarify binding document
The described GPIO reset property is applicable to *all* child PHYs. If
we have one reset line per PHY present on the MDIO bus, these
automatically become properties of the child PHY nodes.

Finally, indicate how the RESET pulse width must be defined, which is
the maximum value of all individual PHYs RESET pulse widths determined
by reading their datasheets.

Fixes: 69226896ad ("mdio_bus: Issue GPIO RESET to PHYs.")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-26 14:45:34 -04:00
Roger Quadros 69226896ad mdio_bus: Issue GPIO RESET to PHYs.
Some boards [1] leave the PHYs at an invalid state
during system power-up or reset thus causing unreliability
issues with the PHY which manifests as PHY not being detected
or link not functional. To fix this, these PHYs need to be RESET
via a GPIO connected to the PHY's RESET pin.

Some boards have a single GPIO controlling the PHY RESET pin of all
PHYs on the bus whereas some others have separate GPIOs controlling
individual PHY RESETs.

In both cases, the RESET de-assertion cannot be done in the PHY driver
as the PHY will not probe till its reset is de-asserted.
So do the RESET de-assertion in the MDIO bus driver.

[1] - am572x-idk, am571x-idk, a437x-idk

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24 12:40:24 -04:00