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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-18 08:09:40 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-18 08:09:40 -0800
commitba4b60e85d6c5fc2242fd24e131a47fb922e5d89 (patch)
tree6be918ce3924d0677bc1029f7d1255fef48a8f85 /Documentation/phy.txt
parent5dba4c56dfa660a85dc8e897990948cdec3734bf (diff)
parent6d0abeca3242a88cab8232e4acd7e2bf088f3bc2 (diff)
downloadtalos-obmc-linux-ba4b60e85d6c5fc2242fd24e131a47fb922e5d89.tar.gz
talos-obmc-linux-ba4b60e85d6c5fc2242fd24e131a47fb922e5d89.zip
Merge 3.14-rc3 into char-misc-next
We need the fixes here for future mei and other patches. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/phy.txt')
-rw-r--r--Documentation/phy.txt26
1 files changed, 19 insertions, 7 deletions
diff --git a/Documentation/phy.txt b/Documentation/phy.txt
index 0103e4b15b0e..ebff6ee52441 100644
--- a/Documentation/phy.txt
+++ b/Documentation/phy.txt
@@ -75,14 +75,26 @@ Before the controller can make use of the PHY, it has to get a reference to
it. This framework provides the following APIs to get a reference to the PHY.
struct phy *phy_get(struct device *dev, const char *string);
+struct phy *phy_optional_get(struct device *dev, const char *string);
struct phy *devm_phy_get(struct device *dev, const char *string);
-
-phy_get and devm_phy_get can be used to get the PHY. In the case of dt boot,
-the string arguments should contain the phy name as given in the dt data and
-in the case of non-dt boot, it should contain the label of the PHY.
-The only difference between the two APIs is that devm_phy_get associates the
-device with the PHY using devres on successful PHY get. On driver detach,
-release function is invoked on the the devres data and devres data is freed.
+struct phy *devm_phy_optional_get(struct device *dev, const char *string);
+
+phy_get, phy_optional_get, devm_phy_get and devm_phy_optional_get can
+be used to get the PHY. In the case of dt boot, the string arguments
+should contain the phy name as given in the dt data and in the case of
+non-dt boot, it should contain the label of the PHY. The two
+devm_phy_get associates the device with the PHY using devres on
+successful PHY get. On driver detach, release function is invoked on
+the the devres data and devres data is freed. phy_optional_get and
+devm_phy_optional_get should be used when the phy is optional. These
+two functions will never return -ENODEV, but instead returns NULL when
+the phy cannot be found.
+
+It should be noted that NULL is a valid phy reference. All phy
+consumer calls on the NULL phy become NOPs. That is the release calls,
+the phy_init() and phy_exit() calls, and phy_power_on() and
+phy_power_off() calls are all NOP when applied to a NULL phy. The NULL
+phy is useful in devices for handling optional phy devices.
5. Releasing a reference to the PHY
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