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authorDavid S. Miller <davem@davemloft.net>2014-02-19 01:24:22 -0500
committerDavid S. Miller <davem@davemloft.net>2014-02-19 01:24:22 -0500
commit1e8d6421cff2c24fe0b345711e7a21af02e8bcf5 (patch)
tree773b30106efb9b48055bc93958e5a94ac53768ce /Documentation/phy.txt
parentf7b12606b5de323a2bb5ca1696558efde8f25441 (diff)
parent960dfc4eb23a28495276b02604d7458e0e1a1ed8 (diff)
downloadlinux-1e8d6421cff2c24fe0b345711e7a21af02e8bcf5.tar.bz2
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/bonding/bond_3ad.h drivers/net/bonding/bond_main.c Two minor conflicts in bonding, both of which were overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
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