From 04c2facad8fee66c981a51852806d8923336f362 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Tue, 4 Feb 2014 18:33:11 +0100 Subject: [PATCH 1/3] 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 Tested-by: Gregory CLEMENT Acked-by: Kishon Vijay Abraham I Signed-off-by: Jason Cooper --- Documentation/phy.txt | 6 ++++++ drivers/phy/phy-core.c | 17 ++++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) 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"); } From 788a4d56ff378bff0b8e685d03a962b36903a149 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Tue, 4 Feb 2014 18:33:12 +0100 Subject: [PATCH 2/3] drivers: phy: Add support for optional phys Add devm_phy_optional_get and phy_optional_get, which should be used when the phy is optional. They does not return an error when the phy does not exist, rather they returns NULL, which is considered as a valid phy, but results in NOPs when used with the consumer API. Signed-off-by: Andrew Lunn Tested-by: Gregory CLEMENT Acked-by: Kishon Vijay Abraham I Signed-off-by: Jason Cooper --- Documentation/phy.txt | 18 +++++++++++------ drivers/phy/phy-core.c | 45 +++++++++++++++++++++++++++++++++++++++++ include/linux/phy/phy.h | 14 +++++++++++++ 3 files changed, 71 insertions(+), 6 deletions(-) diff --git a/Documentation/phy.txt b/Documentation/phy.txt index 2e24b993e95f..ebff6ee52441 100644 --- a/Documentation/phy.txt +++ b/Documentation/phy.txt @@ -75,14 +75,20 @@ 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); +struct phy *devm_phy_optional_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. +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, diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c index a9cdeee20d91..5f5b0f4be5be 100644 --- a/drivers/phy/phy-core.c +++ b/drivers/phy/phy-core.c @@ -425,6 +425,27 @@ struct phy *phy_get(struct device *dev, const char *string) } EXPORT_SYMBOL_GPL(phy_get); +/** + * phy_optional_get() - lookup and obtain a reference to an optional phy. + * @dev: device that requests this phy + * @string: the phy name as given in the dt data or the name of the controller + * port for non-dt case + * + * Returns the phy driver, after getting a refcount to it; or + * NULL if there is no such phy. The caller is responsible for + * calling phy_put() to release that count. + */ +struct phy *phy_optional_get(struct device *dev, const char *string) +{ + struct phy *phy = phy_get(dev, string); + + if (PTR_ERR(phy) == -ENODEV) + phy = NULL; + + return phy; +} +EXPORT_SYMBOL_GPL(phy_optional_get); + /** * devm_phy_get() - lookup and obtain a reference to a phy. * @dev: device that requests this phy @@ -455,6 +476,30 @@ struct phy *devm_phy_get(struct device *dev, const char *string) } EXPORT_SYMBOL_GPL(devm_phy_get); +/** + * devm_phy_optional_get() - lookup and obtain a reference to an optional phy. + * @dev: device that requests this phy + * @string: the phy name as given in the dt data or phy device name + * for non-dt case + * + * Gets the phy using phy_get(), and associates a device with it using + * devres. On driver detach, release function is invoked on the devres + * data, then, devres data is freed. This differs to devm_phy_get() in + * that if the phy does not exist, it is not considered an error and + * -ENODEV will not be returned. Instead the NULL phy is returned, + * which can be passed to all other phy consumer calls. + */ +struct phy *devm_phy_optional_get(struct device *dev, const char *string) +{ + struct phy *phy = devm_phy_get(dev, string); + + if (PTR_ERR(phy) == -ENODEV) + phy = NULL; + + return phy; +} +EXPORT_SYMBOL_GPL(devm_phy_optional_get); + /** * phy_create() - create a new phy * @dev: device that is creating the new phy diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h index e273e5ac19c9..3f83459dbb20 100644 --- a/include/linux/phy/phy.h +++ b/include/linux/phy/phy.h @@ -146,7 +146,9 @@ static inline void phy_set_bus_width(struct phy *phy, int bus_width) phy->attrs.bus_width = bus_width; } 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); +struct phy *devm_phy_optional_get(struct device *dev, const char *string); void phy_put(struct phy *phy); void devm_phy_put(struct device *dev, struct phy *phy); struct phy *of_phy_simple_xlate(struct device *dev, @@ -232,11 +234,23 @@ static inline struct phy *phy_get(struct device *dev, const char *string) return ERR_PTR(-ENOSYS); } +static inline struct phy *phy_optional_get(struct device *dev, + const char *string) +{ + return ERR_PTR(-ENOSYS); +} + static inline struct phy *devm_phy_get(struct device *dev, const char *string) { return ERR_PTR(-ENOSYS); } +static inline struct phy *devm_phy_optional_get(struct device *dev, + const char *string) +{ + return ERR_PTR(-ENOSYS); +} + static inline void phy_put(struct phy *phy) { } From 90aa2997029fa623fe9e3ec3a469a00a34130237 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Tue, 4 Feb 2014 18:33:13 +0100 Subject: [PATCH 3/3] ata: sata_mv: Fix probe failures with optional phys Make use of devm_phy_optional_get() in order to fix probe failures on Armada 370, XP and others, when there is no phy driver available. Signed-off-by: Andrew Lunn Tested-by: Gregory CLEMENT Acked-by: Tejun Heo Acked-by: Kishon Vijay Abraham I Signed-off-by: Jason Cooper --- drivers/ata/sata_mv.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c index 20a7517bd339..52b8181ddafd 100644 --- a/drivers/ata/sata_mv.c +++ b/drivers/ata/sata_mv.c @@ -4126,12 +4126,14 @@ static int mv_platform_probe(struct platform_device *pdev) clk_prepare_enable(hpriv->port_clks[port]); sprintf(port_number, "port%d", port); - hpriv->port_phys[port] = devm_phy_get(&pdev->dev, port_number); + hpriv->port_phys[port] = devm_phy_optional_get(&pdev->dev, + port_number); if (IS_ERR(hpriv->port_phys[port])) { rc = PTR_ERR(hpriv->port_phys[port]); hpriv->port_phys[port] = NULL; - if ((rc != -EPROBE_DEFER) && (rc != -ENODEV)) - dev_warn(&pdev->dev, "error getting phy"); + if (rc != -EPROBE_DEFER) + dev_warn(&pdev->dev, "error getting phy %d", + rc); goto err; } else phy_power_on(hpriv->port_phys[port]);