Commit 02113ba9 authored by Jon Hunter's avatar Jon Hunter Committed by Rafael J. Wysocki
Browse files

PM / clk: Add support for obtaining clocks from device-tree



The PM clocks framework requires clients to pass either a con-id or a
valid clk pointer in order to add a clock to a device. Add a new
function of_pm_clk_add_clks() to allows device clocks to be retrieved
from device-tree and populated for a given device. Note that it is
not necessary to make the compilation of this new function dependent
upon CONFIG_OF because there are stubs functions for the device-tree
APIs used.

In order to handle errors encountered when adding clocks from
device-tree, add a function pm_clk_remove_clk() to remove any clocks
(using a pointer to the clk structure) that have been added
successfully before the error occurred.
Signed-off-by: default avatarJon Hunter <jonathanh@nvidia.com>
Acked-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b562e44f
......@@ -137,6 +137,62 @@ int pm_clk_add_clk(struct device *dev, struct clk *clk)
return __pm_clk_add(dev, NULL, clk);
}
/**
* of_pm_clk_add_clks - Start using device clock(s) for power management.
* @dev: Device whose clock(s) is going to be used for power management.
*
* Add a series of clocks described in the 'clocks' device-tree node for
* a device to the list of clocks used for the power management of @dev.
* On success, returns the number of clocks added. Returns a negative
* error code if there are no clocks in the device node for the device
* or if adding a clock fails.
*/
int of_pm_clk_add_clks(struct device *dev)
{
struct clk **clks;
unsigned int i, count;
int ret;
if (!dev || !dev->of_node)
return -EINVAL;
count = of_count_phandle_with_args(dev->of_node, "clocks",
"#clock-cells");
if (count == 0)
return -ENODEV;
clks = kcalloc(count, sizeof(*clks), GFP_KERNEL);
if (!clks)
return -ENOMEM;
for (i = 0; i < count; i++) {
clks[i] = of_clk_get(dev->of_node, i);
if (IS_ERR(clks[i])) {
ret = PTR_ERR(clks[i]);
goto error;
}
ret = pm_clk_add_clk(dev, clks[i]);
if (ret) {
clk_put(clks[i]);
goto error;
}
}
kfree(clks);
return i;
error:
while (i--)
pm_clk_remove_clk(dev, clks[i]);
kfree(clks);
return ret;
}
/**
* __pm_clk_remove - Destroy PM clock entry.
* @ce: PM clock entry to destroy.
......@@ -197,6 +253,39 @@ void pm_clk_remove(struct device *dev, const char *con_id)
__pm_clk_remove(ce);
}
/**
* pm_clk_remove_clk - Stop using a device clock for power management.
* @dev: Device whose clock should not be used for PM any more.
* @clk: Clock pointer
*
* Remove the clock pointed to by @clk from the list of clocks used for
* the power management of @dev.
*/
void pm_clk_remove_clk(struct device *dev, struct clk *clk)
{
struct pm_subsys_data *psd = dev_to_psd(dev);
struct pm_clock_entry *ce;
if (!psd || !clk)
return;
spin_lock_irq(&psd->lock);
list_for_each_entry(ce, &psd->clock_list, node) {
if (clk == ce->clk)
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.
......
......@@ -42,7 +42,9 @@ extern int pm_clk_create(struct device *dev);
extern void pm_clk_destroy(struct device *dev);
extern int pm_clk_add(struct device *dev, const char *con_id);
extern int pm_clk_add_clk(struct device *dev, struct clk *clk);
extern int of_pm_clk_add_clks(struct device *dev);
extern void pm_clk_remove(struct device *dev, const char *con_id);
extern void pm_clk_remove_clk(struct device *dev, struct clk *clk);
extern int pm_clk_suspend(struct device *dev);
extern int pm_clk_resume(struct device *dev);
#else
......@@ -69,11 +71,18 @@ static inline int pm_clk_add_clk(struct device *dev, struct clk *clk)
{
return -EINVAL;
}
static inline int of_pm_clk_add_clks(struct device *dev)
{
return -EINVAL;
}
static inline void pm_clk_remove(struct device *dev, const char *con_id)
{
}
#define pm_clk_suspend NULL
#define pm_clk_resume NULL
static inline void pm_clk_remove_clk(struct device *dev, struct clk *clk)
{
}
#endif
#ifdef CONFIG_HAVE_CLK
......
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