Add devm_phy_optional_get and phy_optional_get, which should be used
when the phy is optional. They does not return an error when the phy
does not exist, rather they returns NULL, which is considered as a valid
phy, but results in NOPs when used with the consumer API.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

The common clock framework considers NULL a valid clock
reference. This makes handling optional clocks simple, in that if the
optional clock is not available, a NULL reference can be used in the
place of a real clock, simplifying the clock consumer.

Extend this concept to the phy consumer API. A NULL can be passed to
the release calls, the phy_init() and phy_exit() calls, and
phy_power_on() and phy_power_off() and a NOP is performed.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

The PHY framework provides a set of APIs for the PHY drivers to
create/destroy a PHY and APIs for the PHY users to obtain a reference to the
PHY with or without using phandle. For dt-boot, the PHY drivers should
also register *PHY provider* with the framework.

PHY drivers should create the PHY by passing id and ops like init, exit,
power_on and power_off. This framework is also pm runtime enabled.

The documentation for the generic PHY framework is added in
Documentation/phy.txt and the documentation for dt binding can be found at
Documentation/devicetree/bindings/phy/phy-bindings.txt

Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Tested-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>