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| author | Andrew Lunn <andrew@lunn.ch> | 2014-02-04 18:33:11 +0100 |
|---|---|---|
| committer | Jason Cooper <jason@lakedaemon.net> | 2014-02-05 06:27:54 +0100 |
| commit | 04c2facad8fee66c981a51852806d8923336f362 (patch) | |
| tree | 89bda05db2d208a151ed216bc4099d3371c7e6a2 | |
| parent | Linus 3.14-rc1 (diff) | |
| download | linux-04c2facad8fee66c981a51852806d8923336f362.tar.xz linux-04c2facad8fee66c981a51852806d8923336f362.zip | |
drivers: phy: Make NULL a valid phy reference
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: Andrew Lunn <andrew@lunn.ch>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
| -rw-r--r-- | Documentation/phy.txt | 6 | ||||
| -rw-r--r-- | drivers/phy/phy-core.c | 17 |
2 files changed, 22 insertions, 1 deletions
diff --git a/Documentation/phy.txt b/Documentation/phy.txt index 0103e4b15b0e..2e24b993e95f 100644 --- a/Documentation/phy.txt +++ b/Documentation/phy.txt @@ -84,6 +84,12 @@ 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. +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 When the controller no longer needs the PHY, it has to release the reference diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c index 645c867c1257..a9cdeee20d91 100644 --- a/drivers/phy/phy-core.c +++ b/drivers/phy/phy-core.c @@ -162,6 +162,9 @@ int phy_init(struct phy *phy) { int ret; + if (!phy) + return 0; + ret = phy_pm_runtime_get_sync(phy); if (ret < 0 && ret != -ENOTSUPP) return ret; @@ -187,6 +190,9 @@ int phy_exit(struct phy *phy) { int ret; + if (!phy) + return 0; + ret = phy_pm_runtime_get_sync(phy); if (ret < 0 && ret != -ENOTSUPP) return ret; @@ -212,6 +218,9 @@ int phy_power_on(struct phy *phy) { int ret; + if (!phy) + return 0; + ret = phy_pm_runtime_get_sync(phy); if (ret < 0 && ret != -ENOTSUPP) return ret; @@ -240,6 +249,9 @@ int phy_power_off(struct phy *phy) { int ret; + if (!phy) + return 0; + mutex_lock(&phy->mutex); if (phy->power_count == 1 && phy->ops->power_off) { ret = phy->ops->power_off(phy); @@ -308,7 +320,7 @@ err0: */ void phy_put(struct phy *phy) { - if (IS_ERR(phy)) + if (!phy || IS_ERR(phy)) return; module_put(phy->ops->owner); @@ -328,6 +340,9 @@ void devm_phy_put(struct device *dev, struct phy *phy) { int r; + if (!phy) + return; + r = devres_destroy(dev, devm_phy_release, devm_phy_match, phy); dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n"); } |