kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

drivers: phy: Make NULL a valid phy reference

Browse source 
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>
This commit is contained in:
Andrew Lunn 2014-02-04 18:33:11 +01:00 committed by Jason Cooper
parent 38dbfb59d1
commit 04c2facad8
2 changed files with 22 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
Documentation/phy.txt
View file

@ -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

17
drivers/phy/phy-core.c
View file

@ -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");
}