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Commit 59fd9372 authored by Andrew Lunn's avatar Andrew Lunn Committed by Yaniv Gardi
Browse files

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.

Change-Id: Ib1f2147abc25abec05a23a3976609f487a1ed162
Signed-off-by: default avatarAndrew Lunn <andrew@lunn.ch>
Tested-by: default avatarGregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
Git-commit: 04c2facad8fee66c981a51852806d8923336f362
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: default avatarYaniv Gardi <ygardi@codeaurora.org>
parent e4f666bb

Documentation/phy.txt

+6 −0
Original line number Diff line number Diff line
@@ -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

drivers/phy/phy-core.c

+16 −1
Original line number Diff line number Diff line
@@ -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");

}