diff options
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/power/Makefile | 1 | ||||
| -rw-r--r-- | drivers/base/power/clock_ops.c | 430 |
2 files changed, 431 insertions, 0 deletions
diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile index 118c1b92a51..06a7073f902 100644 --- a/drivers/base/power/Makefile +++ b/drivers/base/power/Makefile @@ -3,6 +3,7 @@ obj-$(CONFIG_PM_SLEEP) += main.o wakeup.o obj-$(CONFIG_PM_RUNTIME) += runtime.o obj-$(CONFIG_PM_TRACE_RTC) += trace.o obj-$(CONFIG_PM_OPP) += opp.o +obj-$(CONFIG_HAVE_CLK) += clock_ops.o ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG ccflags-$(CONFIG_PM_VERBOSE) += -DDEBUG diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c new file mode 100644 index 00000000000..d74abf33439 --- /dev/null +++ b/drivers/base/power/clock_ops.c @@ -0,0 +1,430 @@ +/* + * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks + * + * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. + * + * This file is released under the GPLv2. + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/pm.h> +#include <linux/pm_runtime.h> +#include <linux/clk.h> +#include <linux/slab.h> +#include <linux/err.h> + +#ifdef CONFIG_PM_RUNTIME + +struct pm_runtime_clk_data { + struct list_head clock_list; + struct mutex lock; +}; + +enum pce_status { + PCE_STATUS_NONE = 0, + PCE_STATUS_ACQUIRED, + PCE_STATUS_ENABLED, + PCE_STATUS_ERROR, +}; + +struct pm_clock_entry { + struct list_head node; + char *con_id; + struct clk *clk; + enum pce_status status; +}; + +static struct pm_runtime_clk_data *__to_prd(struct device *dev) +{ + return dev ? dev->power.subsys_data : NULL; +} + +/** + * pm_runtime_clk_add - Start using a device clock for runtime PM. + * @dev: Device whose clock is going to be used for runtime PM. + * @con_id: Connection ID of the clock. + * + * Add the clock represented by @con_id to the list of clocks used for + * the runtime PM of @dev. + */ +int pm_runtime_clk_add(struct device *dev, const char *con_id) +{ + struct pm_runtime_clk_data *prd = __to_prd(dev); + struct pm_clock_entry *ce; + + if (!prd) + return -EINVAL; + + ce = kzalloc(sizeof(*ce), GFP_KERNEL); + if (!ce) { + dev_err(dev, "Not enough memory for clock entry.\n"); + return -ENOMEM; + } + + if (con_id) { + ce->con_id = kstrdup(con_id, GFP_KERNEL); + if (!ce->con_id) { + dev_err(dev, + "Not enough memory for clock connection ID.\n"); + kfree(ce); + return -ENOMEM; + } + } + + mutex_lock(&prd->lock); + list_add_tail(&ce->node, &prd->clock_list); + mutex_unlock(&prd->lock); + return 0; +} + +/** + * __pm_runtime_clk_remove - Destroy runtime PM clock entry. + * @ce: Runtime PM clock entry to destroy. + * + * This routine must be called under the mutex protecting the runtime PM list + * of clocks corresponding the the @ce's device. + */ +static void __pm_runtime_clk_remove(struct pm_clock_entry *ce) +{ + if (!ce) + return; + + list_del(&ce->node); + + if (ce->status < PCE_STATUS_ERROR) { + if (ce->status == PCE_STATUS_ENABLED) + clk_disable(ce->clk); + + if (ce->status >= PCE_STATUS_ACQUIRED) + clk_put(ce->clk); + } + + if (ce->con_id) + kfree(ce->con_id); + + kfree(ce); +} + +/** + * pm_runtime_clk_remove - Stop using a device clock for runtime PM. + * @dev: Device whose clock should not be used for runtime PM any more. + * @con_id: Connection ID of the clock. + * + * Remove the clock represented by @con_id from the list of clocks used for + * the runtime PM of @dev. + */ +void pm_runtime_clk_remove(struct device *dev, const char *con_id) +{ + struct pm_runtime_clk_data *prd = __to_prd(dev); + struct pm_clock_entry *ce; + + if (!prd) + return; + + mutex_lock(&prd->lock); + + list_for_each_entry(ce, &prd->clock_list, node) { + if (!con_id && !ce->con_id) { + __pm_runtime_clk_remove(ce); + break; + } else if (!con_id || !ce->con_id) { + continue; + } else if (!strcmp(con_id, ce->con_id)) { + __pm_runtime_clk_remove(ce); + break; + } + } + + mutex_unlock(&prd->lock); +} + +/** + * pm_runtime_clk_init - Initialize a device's list of runtime PM clocks. + * @dev: Device to initialize the list of runtime PM clocks for. + * + * Allocate a struct pm_runtime_clk_data object, initialize its lock member and + * make the @dev's power.subsys_data field point to it. + */ +int pm_runtime_clk_init(struct device *dev) +{ + struct pm_runtime_clk_data *prd; + + prd = kzalloc(sizeof(*prd), GFP_KERNEL); + if (!prd) { + dev_err(dev, "Not enough memory fo runtime PM data.\n"); + return -ENOMEM; + } + + INIT_LIST_HEAD(&prd->clock_list); + mutex_init(&prd->lock); + dev->power.subsys_data = prd; + return 0; +} + +/** + * pm_runtime_clk_destroy - Destroy a device's list of runtime PM clocks. + * @dev: Device to destroy the list of runtime PM clocks for. + * + * Clear the @dev's power.subsys_data field, remove the list of clock entries + * from the struct pm_runtime_clk_data object pointed to by it before and free + * that object. + */ +void pm_runtime_clk_destroy(struct device *dev) +{ + struct pm_runtime_clk_data *prd = __to_prd(dev); + struct pm_clock_entry *ce, *c; + + if (!prd) + return; + + dev->power.subsys_data = NULL; + + mutex_lock(&prd->lock); + + list_for_each_entry_safe_reverse(ce, c, &prd->clock_list, node) + __pm_runtime_clk_remove(ce); + + mutex_unlock(&prd->lock); + + kfree(prd); +} + +/** + * pm_runtime_clk_acquire - Acquire a device clock. + * @dev: Device whose clock is to be acquired. + * @con_id: Connection ID of the clock. + */ +static void pm_runtime_clk_acquire(struct device *dev, + struct pm_clock_entry *ce) +{ + ce->clk = clk_get(dev, ce->con_id); + if (IS_ERR(ce->clk)) { + ce->status = PCE_STATUS_ERROR; + } else { + ce->status = PCE_STATUS_ACQUIRED; + dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id); + } +} + +/** + * pm_runtime_clk_suspend - Disable clocks in a device's runtime PM clock list. + * @dev: Device to disable the clocks for. + */ +int pm_runtime_clk_suspend(struct device *dev) +{ + struct pm_runtime_clk_data *prd = __to_prd(dev); + struct pm_clock_entry *ce; + + dev_dbg(dev, "%s()\n", __func__); + + if (!prd) + return 0; + + mutex_lock(&prd->lock); + + list_for_each_entry_reverse(ce, &prd->clock_list, node) { + if (ce->status == PCE_STATUS_NONE) + pm_runtime_clk_acquire(dev, ce); + + if (ce->status < PCE_STATUS_ERROR) { + clk_disable(ce->clk); + ce->status = PCE_STATUS_ACQUIRED; + } + } + + mutex_unlock(&prd->lock); + + return 0; +} + +/** + * pm_runtime_clk_resume - Enable clocks in a device's runtime PM clock list. + * @dev: Device to enable the clocks for. + */ +int pm_runtime_clk_resume(struct device *dev) +{ + struct pm_runtime_clk_data *prd = __to_prd(dev); + struct pm_clock_entry *ce; + + dev_dbg(dev, "%s()\n", __func__); + + if (!prd) + return 0; + + mutex_lock(&prd->lock); + + list_for_each_entry(ce, &prd->clock_list, node) { + if (ce->status == PCE_STATUS_NONE) + pm_runtime_clk_acquire(dev, ce); + + if (ce->status < PCE_STATUS_ERROR) { + clk_enable(ce->clk); + ce->status = PCE_STATUS_ENABLED; + } + } + + mutex_unlock(&prd->lock); + + return 0; +} + +/** + * pm_runtime_clk_notify - Notify routine for device addition and removal. + * @nb: Notifier block object this function is a member of. + * @action: Operation being carried out by the caller. + * @data: Device the routine is being run for. + * + * For this function to work, @nb must be a member of an object of type + * struct pm_clk_notifier_block containing all of the requisite data. + * Specifically, the pwr_domain member of that object is copied to the device's + * pwr_domain field and its con_ids member is used to populate the device's list + * of runtime PM clocks, depending on @action. + * + * If the device's pwr_domain field is already populated with a value different + * from the one stored in the struct pm_clk_notifier_block object, the function + * does nothing. + */ +static int pm_runtime_clk_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct pm_clk_notifier_block *clknb; + struct device *dev = data; + char *con_id; + int error; + + dev_dbg(dev, "%s() %ld\n", __func__, action); + + clknb = container_of(nb, struct pm_clk_notifier_block, nb); + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + if (dev->pwr_domain) + break; + + error = pm_runtime_clk_init(dev); + if (error) + break; + + dev->pwr_domain = clknb->pwr_domain; + if (clknb->con_ids[0]) { + for (con_id = clknb->con_ids[0]; *con_id; con_id++) + pm_runtime_clk_add(dev, con_id); + } else { + pm_runtime_clk_add(dev, NULL); + } + + break; + case BUS_NOTIFY_DEL_DEVICE: + if (dev->pwr_domain != clknb->pwr_domain) + break; + + dev->pwr_domain = NULL; + pm_runtime_clk_destroy(dev); + break; + } + + return 0; +} + +#else /* !CONFIG_PM_RUNTIME */ + +/** + * enable_clock - Enable a device clock. + * @dev: Device whose clock is to be enabled. + * @con_id: Connection ID of the clock. + */ +static void enable_clock(struct device *dev, const char *con_id) +{ + struct clk *clk; + + clk = clk_get(dev, con_id); + if (!IS_ERR(clk)) { + clk_enable(clk); + clk_put(clk); + dev_info(dev, "Runtime PM disabled, clock forced on.\n"); + } +} + +/** + * disable_clock - Disable a device clock. + * @dev: Device whose clock is to be disabled. + * @con_id: Connection ID of the clock. + */ +static void disable_clock(struct device *dev, const char *con_id) +{ + struct clk *clk; + + clk = clk_get(dev, con_id); + if (!IS_ERR(clk)) { + clk_disable(clk); + clk_put(clk); + dev_info(dev, "Runtime PM disabled, clock forced off.\n"); + } +} + +/** + * pm_runtime_clk_notify - Notify routine for device addition and removal. + * @nb: Notifier block object this function is a member of. + * @action: Operation being carried out by the caller. + * @data: Device the routine is being run for. + * + * For this function to work, @nb must be a member of an object of type + * struct pm_clk_notifier_block containing all of the requisite data. + * Specifically, the con_ids member of that object is used to enable or disable + * the device's clocks, depending on @action. + */ +static int pm_runtime_clk_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct pm_clk_notifier_block *clknb; + struct device *dev = data; + + dev_dbg(dev, "%s() %ld\n", __func__, action); + + clknb = container_of(nb, struct pm_clk_notifier_block, nb); + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + if (clknb->con_ids[0]) { + for (con_id = clknb->con_ids[0]; *con_id; con_id++) + enable_clock(dev, con_id); + } else { + enable_clock(dev, NULL); + } + break; + case BUS_NOTIFY_DEL_DEVICE: + if (clknb->con_ids[0]) { + for (con_id = clknb->con_ids[0]; *con_id; con_id++) + disable_clock(dev, con_id); + } else { + disable_clock(dev, NULL); + } + break; + } + + return 0; +} + +#endif /* !CONFIG_PM_RUNTIME */ + +/** + * pm_runtime_clk_add_notifier - Add bus type notifier for runtime PM clocks. + * @bus: Bus type to add the notifier to. + * @clknb: Notifier to be added to the given bus type. + * + * The nb member of @clknb is not expected to be initialized and its + * notifier_call member will be replaced with pm_runtime_clk_notify(). However, + * the remaining members of @clknb should be populated prior to calling this + * routine. + */ +void pm_runtime_clk_add_notifier(struct bus_type *bus, + struct pm_clk_notifier_block *clknb) +{ + if (!bus || !clknb) + return; + + clknb->nb.notifier_call = pm_runtime_clk_notify; + bus_register_notifier(bus, &clknb->nb); +} |