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- /*
- * 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/kernel.h>
- #include <linux/device.h>
- #include <linux/io.h>
- #include <linux/pm.h>
- #include <linux/pm_clock.h>
- #include <linux/clk.h>
- #include <linux/clkdev.h>
- #include <linux/slab.h>
- #include <linux/err.h>
- #include <linux/pm_runtime.h>
- #ifdef CONFIG_PM_CLK
- 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;
- };
- /**
- * pm_clk_enable - Enable a clock, reporting any errors
- * @dev: The device for the given clock
- * @ce: PM clock entry corresponding to the clock.
- */
- static inline void __pm_clk_enable(struct device *dev, struct pm_clock_entry *ce)
- {
- int ret;
- if (ce->status < PCE_STATUS_ERROR) {
- ret = clk_enable(ce->clk);
- if (!ret)
- ce->status = PCE_STATUS_ENABLED;
- else
- dev_err(dev, "%s: failed to enable clk %p, error %d\n",
- __func__, ce->clk, ret);
- }
- }
- /**
- * pm_clk_acquire - Acquire a device clock.
- * @dev: Device whose clock is to be acquired.
- * @ce: PM clock entry corresponding to the clock.
- */
- static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
- {
- if (!ce->clk)
- ce->clk = clk_get(dev, ce->con_id);
- if (IS_ERR(ce->clk)) {
- ce->status = PCE_STATUS_ERROR;
- } else {
- clk_prepare(ce->clk);
- ce->status = PCE_STATUS_ACQUIRED;
- dev_dbg(dev, "Clock %pC con_id %s managed by runtime PM.\n",
- ce->clk, ce->con_id);
- }
- }
- static int __pm_clk_add(struct device *dev, const char *con_id,
- struct clk *clk)
- {
- struct pm_subsys_data *psd = dev_to_psd(dev);
- struct pm_clock_entry *ce;
- if (!psd)
- return -EINVAL;
- ce = kzalloc(sizeof(*ce), GFP_KERNEL);
- if (!ce)
- 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;
- }
- } else {
- if (IS_ERR(clk)) {
- kfree(ce);
- return -ENOENT;
- }
- ce->clk = clk;
- }
- pm_clk_acquire(dev, ce);
- spin_lock_irq(&psd->lock);
- list_add_tail(&ce->node, &psd->clock_list);
- spin_unlock_irq(&psd->lock);
- return 0;
- }
- /**
- * pm_clk_add - Start using a device clock for power management.
- * @dev: Device whose clock is going to be used for power management.
- * @con_id: Connection ID of the clock.
- *
- * Add the clock represented by @con_id to the list of clocks used for
- * the power management of @dev.
- */
- int pm_clk_add(struct device *dev, const char *con_id)
- {
- return __pm_clk_add(dev, con_id, NULL);
- }
- /**
- * pm_clk_add_clk - Start using a device clock for power management.
- * @dev: Device whose clock is going to be used for power management.
- * @clk: Clock pointer
- *
- * Add the clock to the list of clocks used for the power management of @dev.
- * The power-management code will take control of the clock reference, so
- * callers should not call clk_put() on @clk after this function sucessfully
- * returned.
- */
- int pm_clk_add_clk(struct device *dev, struct clk *clk)
- {
- return __pm_clk_add(dev, NULL, clk);
- }
- /**
- * __pm_clk_remove - Destroy PM clock entry.
- * @ce: PM clock entry to destroy.
- */
- static void __pm_clk_remove(struct pm_clock_entry *ce)
- {
- if (!ce)
- return;
- if (ce->status < PCE_STATUS_ERROR) {
- if (ce->status == PCE_STATUS_ENABLED)
- clk_disable(ce->clk);
- if (ce->status >= PCE_STATUS_ACQUIRED) {
- clk_unprepare(ce->clk);
- clk_put(ce->clk);
- }
- }
- kfree(ce->con_id);
- kfree(ce);
- }
- /**
- * pm_clk_remove - Stop using a device clock for power management.
- * @dev: Device whose clock should not be used for 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 power management of @dev.
- */
- void pm_clk_remove(struct device *dev, const char *con_id)
- {
- struct pm_subsys_data *psd = dev_to_psd(dev);
- struct pm_clock_entry *ce;
- if (!psd)
- return;
- spin_lock_irq(&psd->lock);
- list_for_each_entry(ce, &psd->clock_list, node) {
- if (!con_id && !ce->con_id)
- goto remove;
- else if (!con_id || !ce->con_id)
- continue;
- else if (!strcmp(con_id, ce->con_id))
- goto remove;
- }
- spin_unlock_irq(&psd->lock);
- return;
- remove:
- list_del(&ce->node);
- spin_unlock_irq(&psd->lock);
- __pm_clk_remove(ce);
- }
- /**
- * pm_clk_init - Initialize a device's list of power management clocks.
- * @dev: Device to initialize the list of PM clocks for.
- *
- * Initialize the lock and clock_list members of the device's pm_subsys_data
- * object.
- */
- void pm_clk_init(struct device *dev)
- {
- struct pm_subsys_data *psd = dev_to_psd(dev);
- if (psd)
- INIT_LIST_HEAD(&psd->clock_list);
- }
- /**
- * pm_clk_create - Create and initialize a device's list of PM clocks.
- * @dev: Device to create and initialize the list of PM clocks for.
- *
- * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
- * members and make the @dev's power.subsys_data field point to it.
- */
- int pm_clk_create(struct device *dev)
- {
- return dev_pm_get_subsys_data(dev);
- }
- /**
- * pm_clk_destroy - Destroy a device's list of power management clocks.
- * @dev: Device to destroy the list of PM clocks for.
- *
- * Clear the @dev's power.subsys_data field, remove the list of clock entries
- * from the struct pm_subsys_data object pointed to by it before and free
- * that object.
- */
- void pm_clk_destroy(struct device *dev)
- {
- struct pm_subsys_data *psd = dev_to_psd(dev);
- struct pm_clock_entry *ce, *c;
- struct list_head list;
- if (!psd)
- return;
- INIT_LIST_HEAD(&list);
- spin_lock_irq(&psd->lock);
- list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
- list_move(&ce->node, &list);
- spin_unlock_irq(&psd->lock);
- dev_pm_put_subsys_data(dev);
- list_for_each_entry_safe_reverse(ce, c, &list, node) {
- list_del(&ce->node);
- __pm_clk_remove(ce);
- }
- }
- /**
- * pm_clk_suspend - Disable clocks in a device's PM clock list.
- * @dev: Device to disable the clocks for.
- */
- int pm_clk_suspend(struct device *dev)
- {
- struct pm_subsys_data *psd = dev_to_psd(dev);
- struct pm_clock_entry *ce;
- unsigned long flags;
- dev_dbg(dev, "%s()\n", __func__);
- if (!psd)
- return 0;
- spin_lock_irqsave(&psd->lock, flags);
- list_for_each_entry_reverse(ce, &psd->clock_list, node) {
- if (ce->status < PCE_STATUS_ERROR) {
- if (ce->status == PCE_STATUS_ENABLED)
- clk_disable(ce->clk);
- ce->status = PCE_STATUS_ACQUIRED;
- }
- }
- spin_unlock_irqrestore(&psd->lock, flags);
- return 0;
- }
- /**
- * pm_clk_resume - Enable clocks in a device's PM clock list.
- * @dev: Device to enable the clocks for.
- */
- int pm_clk_resume(struct device *dev)
- {
- struct pm_subsys_data *psd = dev_to_psd(dev);
- struct pm_clock_entry *ce;
- unsigned long flags;
- dev_dbg(dev, "%s()\n", __func__);
- if (!psd)
- return 0;
- spin_lock_irqsave(&psd->lock, flags);
- list_for_each_entry(ce, &psd->clock_list, node)
- __pm_clk_enable(dev, ce);
- spin_unlock_irqrestore(&psd->lock, flags);
- return 0;
- }
- /**
- * pm_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 pm_domain member of that object is copied to the device's
- * pm_domain field and its con_ids member is used to populate the device's list
- * of PM clocks, depending on @action.
- *
- * If the device's pm_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_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->pm_domain)
- break;
- error = pm_clk_create(dev);
- if (error)
- break;
- dev->pm_domain = clknb->pm_domain;
- if (clknb->con_ids[0]) {
- for (con_id = clknb->con_ids; *con_id; con_id++)
- pm_clk_add(dev, *con_id);
- } else {
- pm_clk_add(dev, NULL);
- }
- break;
- case BUS_NOTIFY_DEL_DEVICE:
- if (dev->pm_domain != clknb->pm_domain)
- break;
- dev->pm_domain = NULL;
- pm_clk_destroy(dev);
- break;
- }
- return 0;
- }
- int pm_clk_runtime_suspend(struct device *dev)
- {
- int ret;
- dev_dbg(dev, "%s\n", __func__);
- ret = pm_generic_runtime_suspend(dev);
- if (ret) {
- dev_err(dev, "failed to suspend device\n");
- return ret;
- }
- ret = pm_clk_suspend(dev);
- if (ret) {
- dev_err(dev, "failed to suspend clock\n");
- pm_generic_runtime_resume(dev);
- return ret;
- }
- return 0;
- }
- int pm_clk_runtime_resume(struct device *dev)
- {
- int ret;
- dev_dbg(dev, "%s\n", __func__);
- ret = pm_clk_resume(dev);
- if (ret) {
- dev_err(dev, "failed to resume clock\n");
- return ret;
- }
- return pm_generic_runtime_resume(dev);
- }
- #else /* !CONFIG_PM_CLK */
- /**
- * 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_prepare_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_unprepare(clk);
- clk_put(clk);
- dev_info(dev, "Runtime PM disabled, clock forced off.\n");
- }
- }
- /**
- * pm_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_clk_notify(struct notifier_block *nb,
- unsigned long action, void *data)
- {
- struct pm_clk_notifier_block *clknb;
- struct device *dev = data;
- char **con_id;
- dev_dbg(dev, "%s() %ld\n", __func__, action);
- clknb = container_of(nb, struct pm_clk_notifier_block, nb);
- switch (action) {
- case BUS_NOTIFY_BIND_DRIVER:
- if (clknb->con_ids[0]) {
- for (con_id = clknb->con_ids; *con_id; con_id++)
- enable_clock(dev, *con_id);
- } else {
- enable_clock(dev, NULL);
- }
- break;
- case BUS_NOTIFY_UNBOUND_DRIVER:
- if (clknb->con_ids[0]) {
- for (con_id = clknb->con_ids; *con_id; con_id++)
- disable_clock(dev, *con_id);
- } else {
- disable_clock(dev, NULL);
- }
- break;
- }
- return 0;
- }
- #endif /* !CONFIG_PM_CLK */
- /**
- * pm_clk_add_notifier - Add bus type notifier for power management 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_clk_notify(). However,
- * the remaining members of @clknb should be populated prior to calling this
- * routine.
- */
- void pm_clk_add_notifier(struct bus_type *bus,
- struct pm_clk_notifier_block *clknb)
- {
- if (!bus || !clknb)
- return;
- clknb->nb.notifier_call = pm_clk_notify;
- bus_register_notifier(bus, &clknb->nb);
- }
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