/drivers/base/power/clock_ops.c
https://bitbucket.org/ndreys/linux-sunxi · C · 431 lines · 255 code · 71 blank · 105 comment · 49 complexity · 0689e5094c78b913bf0041f34a291297 MD5 · raw file
- /*
- * 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; *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;
- 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_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);
- }