net: ipa: use runtime PM core

Use the runtime power management core to cause hardware suspend and
resume to occur.  Enable it in ipa_clock_init() (without autosuspend),
and disable it in ipa_clock_exit().

Use ipa_runtime_suspend() as the ->runtime_suspend power operation,
and arrange for it to be called by having ipa_clock_get() call
pm_runtime_get_sync() when the first clock reference is taken.
Similarly, use ipa_runtime_resume() as the ->runtime_resume power
operation, and pm_runtime_put() when the last IPA clock reference
is dropped.

Introduce ipa_runtime_idle() as the ->runtime_idle power operation,
and have it return a non-zero value; this way suspend will never
occur except when forced.

Use pm_runtime_force_suspend() and pm_runtime_force_resume() as the
system suspend and resume callbacks, and remove ipa_suspend() and
ipa_resume().

Store a pointer to the device structure passed to ipa_clock_init(),
so it can be used by ipa_clock_exit() to disable runtime power
management.

For now we preserve IPA clock reference counting.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ipa/ipa_clock.c b/drivers/net/ipa/ipa_clock.c
index c0a8fdf..f1ee0b4 100644 (file)
--- a/drivers/net/ipa/ipa_clock.c
+++ b/drivers/net/ipa/ipa_clock.c
@@ -60,6 +60,7 @@ enum ipa_power_flag {
  * struct ipa_clock - IPA clocking information
  * @count:             Clocking reference count
  * @mutex:             Protects clock enable/disable
+ * @dev:               IPA device pointer
  * @core:              IPA core clock
  * @flags:             Boolean state flags
  * @interconnect_count:        Number of elements in interconnect[]
@@ -68,6 +69,7 @@ enum ipa_power_flag {
 struct ipa_clock {
        refcount_t count;
        struct mutex mutex; /* protects clock enable/disable */
+       struct device *dev;
        struct clk *core;
        DECLARE_BITMAP(flags, IPA_POWER_FLAG_COUNT);
        u32 interconnect_count;
@@ -263,13 +265,29 @@ static int ipa_runtime_resume(struct device *dev)
        return 0;
 }
 
+static int ipa_runtime_idle(struct device *dev)
+{
+       return -EAGAIN;
+}
+
 /* Get an IPA clock reference, but only if the reference count is
  * already non-zero.  Returns true if the additional reference was
  * added successfully, or false otherwise.
  */
 bool ipa_clock_get_additional(struct ipa *ipa)
 {
-       return refcount_inc_not_zero(&ipa->clock->count);
+       struct device *dev;
+       int ret;
+
+       if (!refcount_inc_not_zero(&ipa->clock->count))
+               return false;
+
+       dev = &ipa->pdev->dev;
+       ret = pm_runtime_get_sync(dev);
+       if (ret < 0)
+               dev_err(dev, "error %d enabling power\n", ret);
+
+       return true;
 }
 
 /* Get an IPA clock reference.  If the reference count is non-zero, it is
@@ -283,6 +301,7 @@ bool ipa_clock_get_additional(struct ipa *ipa)
 int ipa_clock_get(struct ipa *ipa)
 {
        struct ipa_clock *clock = ipa->clock;
+       struct device *dev;
        int ret;
 
        /* If the clock is running, just bump the reference count */
@@ -298,7 +317,8 @@ int ipa_clock_get(struct ipa *ipa)
                goto out_mutex_unlock;
        }
 
-       ret = ipa_runtime_resume(&ipa->pdev->dev);
+       dev = &ipa->pdev->dev;
+       ret = pm_runtime_get_sync(dev);
 
        refcount_set(&clock->count, 1);
 
@@ -313,14 +333,17 @@ out_mutex_unlock:
  */
 int ipa_clock_put(struct ipa *ipa)
 {
+       struct device *dev = &ipa->pdev->dev;
        struct ipa_clock *clock = ipa->clock;
+       int last;
        int ret;
 
        /* If this is not the last reference there's nothing more to do */
-       if (!refcount_dec_and_mutex_lock(&clock->count, &clock->mutex))
-               return 0;
+       last = refcount_dec_and_mutex_lock(&clock->count, &clock->mutex);
 
-       ret = ipa_runtime_suspend(&ipa->pdev->dev);
+       ret = pm_runtime_put(dev);
+       if (!last)
+               return ret;
 
        mutex_unlock(&clock->mutex);
 
@@ -394,6 +417,7 @@ ipa_clock_init(struct device *dev, const struct ipa_clock_data *data)
                ret = -ENOMEM;
                goto err_clk_put;
        }
+       clock->dev = dev;
        clock->core = clk;
        clock->interconnect_count = data->interconnect_count;
 
@@ -404,6 +428,9 @@ ipa_clock_init(struct device *dev, const struct ipa_clock_data *data)
        mutex_init(&clock->mutex);
        refcount_set(&clock->count, 0);
 
+       pm_runtime_dont_use_autosuspend(dev);
+       pm_runtime_enable(dev);
+
        return clock;
 
 err_kfree:
@@ -420,43 +447,17 @@ void ipa_clock_exit(struct ipa_clock *clock)
        struct clk *clk = clock->core;
 
        WARN_ON(refcount_read(&clock->count) != 0);
+       pm_runtime_disable(clock->dev);
        mutex_destroy(&clock->mutex);
        ipa_interconnect_exit(clock);
        kfree(clock);
        clk_put(clk);
 }
 
-/**
- * ipa_suspend() - Power management system suspend callback
- * @dev:       IPA device structure
- *
- * Return:     0 on success, or a negative error code
- *
- * Called by the PM framework when a system suspend operation is invoked.
- * Suspends endpoints and releases the clock reference held to keep
- * the IPA clock running until this point.
- */
-static int ipa_suspend(struct device *dev)
-{
-       return ipa_runtime_suspend(dev);
-}
-
-/**
- * ipa_resume() - Power management system resume callback
- * @dev:       IPA device structure
- *
- * Return:     0 on success, or a negative error code
- *
- * Called by the PM framework when a system resume operation is invoked.
- * Takes an IPA clock reference to keep the clock running until suspend,
- * and resumes endpoints.
- */
-static int ipa_resume(struct device *dev)
-{
-       return ipa_runtime_resume(dev);
-}
-
 const struct dev_pm_ops ipa_pm_ops = {
-       .suspend        = ipa_suspend,
-       .resume         = ipa_resume,
+       .suspend                = pm_runtime_force_suspend,
+       .resume                 = pm_runtime_force_resume,
+       .runtime_suspend        = ipa_runtime_suspend,
+       .runtime_resume         = ipa_runtime_resume,
+       .runtime_idle           = ipa_runtime_idle,
 };