From: Viresh Kumar viresh.kumar@linaro.org
This allows the OPP core to request/free the regulator resource, attached to a device OPP. The regulator device is fetched using the name provided by the driver, while calling: dev_pm_opp_set_regulator().
This will work for both OPP-v1 and v2 bindings.
This is a preliminary step for moving the OPP switching logic into the OPP core.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Reviewed-by: Stephen Boyd sboyd@codeaurora.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com (cherry picked from commit 9f8ea969d5cfdd4353d2adb004e8e2286b984369) Signed-off-by: Alex Shi alex.shi@linaro.org --- drivers/base/power/opp/core.c | 111 ++++++++++++++++++++++++++++++++++++++++++ drivers/base/power/opp/opp.h | 4 ++ include/linux/pm_opp.h | 9 ++++ 3 files changed, 124 insertions(+)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index cf351d3..1e22b71 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -19,6 +19,7 @@ #include <linux/device.h> #include <linux/of.h> #include <linux/export.h> +#include <linux/regulator/consumer.h>
#include "opp.h"
@@ -565,6 +566,9 @@ static void _remove_device_opp(struct device_opp *dev_opp) if (dev_opp->prop_name) return;
+ if (!IS_ERR_OR_NULL(dev_opp->regulator)) + return; + list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp, node);
@@ -1085,6 +1089,113 @@ unlock: } EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
+/** + * dev_pm_opp_set_regulator() - Set regulator name for the device + * @dev: Device for which regulator name is being set. + * @name: Name of the regulator. + * + * In order to support OPP switching, OPP layer needs to know the name of the + * device's regulator, as the core would be required to switch voltages as well. + * + * This must be called before any OPPs are initialized for the device. + * + * Locking: The internal device_opp and opp structures are RCU protected. + * Hence this function internally uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + */ +int dev_pm_opp_set_regulator(struct device *dev, const char *name) +{ + struct device_opp *dev_opp; + struct regulator *reg; + int ret; + + mutex_lock(&dev_opp_list_lock); + + dev_opp = _add_device_opp(dev); + if (!dev_opp) { + ret = -ENOMEM; + goto unlock; + } + + /* This should be called before OPPs are initialized */ + if (WARN_ON(!list_empty(&dev_opp->opp_list))) { + ret = -EBUSY; + goto err; + } + + /* Already have a regulator set */ + if (WARN_ON(!IS_ERR_OR_NULL(dev_opp->regulator))) { + ret = -EBUSY; + goto err; + } + /* Allocate the regulator */ + reg = regulator_get_optional(dev, name); + if (IS_ERR(reg)) { + ret = PTR_ERR(reg); + if (ret != -EPROBE_DEFER) + dev_err(dev, "%s: no regulator (%s) found: %d\n", + __func__, name, ret); + goto err; + } + + dev_opp->regulator = reg; + + mutex_unlock(&dev_opp_list_lock); + return 0; + +err: + _remove_device_opp(dev_opp); +unlock: + mutex_unlock(&dev_opp_list_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulator); + +/** + * dev_pm_opp_put_regulator() - Releases resources blocked for regulator + * @dev: Device for which regulator was set. + * + * Locking: The internal device_opp and opp structures are RCU protected. + * Hence this function internally uses RCU updater strategy with mutex locks + * to keep the integrity of the internal data structures. Callers should ensure + * that this function is *NOT* called under RCU protection or in contexts where + * mutex cannot be locked. + */ +void dev_pm_opp_put_regulator(struct device *dev) +{ + struct device_opp *dev_opp; + + mutex_lock(&dev_opp_list_lock); + + /* Check for existing list for 'dev' first */ + dev_opp = _find_device_opp(dev); + if (IS_ERR(dev_opp)) { + dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp)); + goto unlock; + } + + if (IS_ERR_OR_NULL(dev_opp->regulator)) { + dev_err(dev, "%s: Doesn't have regulator set\n", __func__); + goto unlock; + } + + /* Make sure there are no concurrent readers while updating dev_opp */ + WARN_ON(!list_empty(&dev_opp->opp_list)); + + regulator_put(dev_opp->regulator); + dev_opp->regulator = ERR_PTR(-EINVAL); + + /* Try freeing device_opp if this was the last blocking resource */ + _remove_device_opp(dev_opp); + +unlock: + mutex_unlock(&dev_opp_list_lock); +} +EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulator); + static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp, struct device_node *np) { diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h index 690638e..416293b 100644 --- a/drivers/base/power/opp/opp.h +++ b/drivers/base/power/opp/opp.h @@ -22,6 +22,8 @@ #include <linux/rculist.h> #include <linux/rcupdate.h>
+struct regulator; + /* Lock to allow exclusive modification to the device and opp lists */ extern struct mutex dev_opp_list_lock;
@@ -132,6 +134,7 @@ struct device_list_opp { * @supported_hw: Array of version number to support. * @supported_hw_count: Number of elements in supported_hw array. * @prop_name: A name to postfix to many DT properties, while parsing them. + * @regulator: Supply regulator * @dentry: debugfs dentry pointer of the real device directory (not links). * @dentry_name: Name of the real dentry. * @@ -159,6 +162,7 @@ struct device_opp { unsigned int *supported_hw; unsigned int supported_hw_count; const char *prop_name; + struct regulator *regulator;
#ifdef CONFIG_DEBUG_FS struct dentry *dentry; diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 95403d2..c70a18a 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -60,6 +60,8 @@ int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions, void dev_pm_opp_put_supported_hw(struct device *dev); int dev_pm_opp_set_prop_name(struct device *dev, const char *name); void dev_pm_opp_put_prop_name(struct device *dev); +int dev_pm_opp_set_regulator(struct device *dev, const char *name); +void dev_pm_opp_put_regulator(struct device *dev); #else static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp) { @@ -151,6 +153,13 @@ static inline int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
static inline void dev_pm_opp_put_prop_name(struct device *dev) {}
+static inline int dev_pm_opp_set_regulator(struct device *dev, const char *name) +{ + return -EINVAL; +} + +static inline void dev_pm_opp_put_regulator(struct device *dev) {} + #endif /* CONFIG_PM_OPP */
#if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)