linux/drivers/base/power/clock_ops.c
Tomeu Vizoso 989561de9b PM / Domains: add setter for dev.pm_domain
Adds a function that sets the pointer to dev_pm_domain in struct device
and that warns if the device has already finished probing. The reason
why we want to enforce that is because in the general case that can
cause problems and also that we can simplify code quite a bit if we can
always assume that.

This patch also changes all current code that directly sets the
dev.pm_domain pointer.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-08 01:12:06 +01:00

512 lines
12 KiB
C

/*
* 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_domain.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_set(dev, 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_set(dev, 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_DRIVER_NOT_BOUND:
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);
}