1 files changed, 123 insertions, 65 deletions

diff --git a/drivers/net/ipa/ipa_clock.c b/drivers/net/ipa/ipa_clock.c
index 69ef6ea41e61..6df66c574d59 100644
--- a/drivers/net/ipa/ipa_clock.c
+++ b/drivers/net/ipa/ipa_clock.c
@@ -4,14 +4,16 @@
  * Copyright (C) 2018-2021 Linaro Ltd.
  */
 
-#include <linux/refcount.h>
-#include <linux/mutex.h>
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/interconnect.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/bitops.h>
 
 #include "ipa.h"
 #include "ipa_clock.h"
+#include "ipa_endpoint.h"
 #include "ipa_modem.h"
 #include "ipa_data.h"
 
@@ -43,17 +45,27 @@ struct ipa_interconnect {
 };
 
 /**
+ * enum ipa_power_flag - IPA power flags
+ * @IPA_POWER_FLAG_RESUMED:	Whether resume from suspend has been signaled
+ * @IPA_POWER_FLAG_COUNT:	Number of defined power flags
+ */
+enum ipa_power_flag {
+	IPA_POWER_FLAG_RESUMED,
+	IPA_POWER_FLAG_COUNT,		/* Last; not a 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[]
  * @interconnect:	Interconnect array
  */
 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;
 	struct ipa_interconnect *interconnect;
 };
@@ -144,8 +156,12 @@ static int ipa_interconnect_enable(struct ipa *ipa)
 		ret = icc_set_bw(interconnect->path,
 				 interconnect->average_bandwidth,
 				 interconnect->peak_bandwidth);
-		if (ret)
+		if (ret) {
+			dev_err(&ipa->pdev->dev,
+				"error %d enabling %s interconnect\n",
+				ret, icc_get_name(interconnect->path));
 			goto out_unwind;
+		}
 		interconnect++;
 	}
 
@@ -159,10 +175,11 @@ out_unwind:
 }
 
 /* To disable an interconnect, we just its bandwidth to 0 */
-static void ipa_interconnect_disable(struct ipa *ipa)
+static int ipa_interconnect_disable(struct ipa *ipa)
 {
 	struct ipa_interconnect *interconnect;
 	struct ipa_clock *clock = ipa->clock;
+	struct device *dev = &ipa->pdev->dev;
 	int result = 0;
 	u32 count;
 	int ret;
@@ -172,13 +189,16 @@ static void ipa_interconnect_disable(struct ipa *ipa)
 	while (count--) {
 		interconnect--;
 		ret = icc_set_bw(interconnect->path, 0, 0);
-		if (ret && !result)
-			result = ret;
+		if (ret) {
+			dev_err(dev, "error %d disabling %s interconnect\n",
+				ret, icc_get_name(interconnect->path));
+			/* Try to disable all; record only the first error */
+			if (!result)
+				result = ret;
+		}
 	}
 
-	if (result)
-		dev_err(&ipa->pdev->dev,
-			"error %d disabling IPA interconnects\n", ret);
+	return result;
 }
 
 /* Turn on IPA clocks, including interconnects */
@@ -191,78 +211,74 @@ static int ipa_clock_enable(struct ipa *ipa)
 		return ret;
 
 	ret = clk_prepare_enable(ipa->clock->core);
-	if (ret)
-		ipa_interconnect_disable(ipa);
+	if (ret) {
+		dev_err(&ipa->pdev->dev, "error %d enabling core clock\n", ret);
+		(void)ipa_interconnect_disable(ipa);
+	}
 
 	return ret;
 }
 
 /* Inverse of ipa_clock_enable() */
-static void ipa_clock_disable(struct ipa *ipa)
+static int ipa_clock_disable(struct ipa *ipa)
 {
 	clk_disable_unprepare(ipa->clock->core);
-	ipa_interconnect_disable(ipa);
-}
 
-/* 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);
+	return ipa_interconnect_disable(ipa);
 }
 
-/* Get an IPA clock reference.  If the reference count is non-zero, it is
- * incremented and return is immediate.  Otherwise it is checked again
- * under protection of the mutex, and if appropriate the IPA clock
- * is enabled.
- *
- * Incrementing the reference count is intentionally deferred until
- * after the clock is running and endpoints are resumed.
- */
-void ipa_clock_get(struct ipa *ipa)
+static int ipa_runtime_suspend(struct device *dev)
 {
-	struct ipa_clock *clock = ipa->clock;
-	int ret;
+	struct ipa *ipa = dev_get_drvdata(dev);
 
-	/* If the clock is running, just bump the reference count */
-	if (ipa_clock_get_additional(ipa))
-		return;
+	/* Endpoints aren't usable until setup is complete */
+	if (ipa->setup_complete) {
+		__clear_bit(IPA_POWER_FLAG_RESUMED, ipa->clock->flags);
+		ipa_endpoint_suspend(ipa);
+		gsi_suspend(&ipa->gsi);
+	}
 
-	/* Otherwise get the mutex and check again */
-	mutex_lock(&clock->mutex);
+	return ipa_clock_disable(ipa);
+}
 
-	/* A reference might have been added before we got the mutex. */
-	if (ipa_clock_get_additional(ipa))
-		goto out_mutex_unlock;
+static int ipa_runtime_resume(struct device *dev)
+{
+	struct ipa *ipa = dev_get_drvdata(dev);
+	int ret;
 
 	ret = ipa_clock_enable(ipa);
-	if (ret) {
-		dev_err(&ipa->pdev->dev, "error %d enabling IPA clock\n", ret);
-		goto out_mutex_unlock;
+	if (WARN_ON(ret < 0))
+		return ret;
+
+	/* Endpoints aren't usable until setup is complete */
+	if (ipa->setup_complete) {
+		gsi_resume(&ipa->gsi);
+		ipa_endpoint_resume(ipa);
 	}
 
-	refcount_set(&clock->count, 1);
+	return 0;
+}
 
-out_mutex_unlock:
-	mutex_unlock(&clock->mutex);
+static int ipa_runtime_idle(struct device *dev)
+{
+	return -EAGAIN;
 }
 
-/* Attempt to remove an IPA clock reference.  If this represents the
- * last reference, disable the IPA clock under protection of the mutex.
+/* Get an IPA clock reference.  If the reference count is non-zero, it is
+ * incremented and return is immediate.  Otherwise the IPA clock is
+ * enabled.
  */
-void ipa_clock_put(struct ipa *ipa)
+int ipa_clock_get(struct ipa *ipa)
 {
-	struct ipa_clock *clock = ipa->clock;
-
-	/* If this is not the last reference there's nothing more to do */
-	if (!refcount_dec_and_mutex_lock(&clock->count, &clock->mutex))
-		return;
-
-	ipa_clock_disable(ipa);
+	return pm_runtime_get_sync(&ipa->pdev->dev);
+}
 
-	mutex_unlock(&clock->mutex);
+/* Attempt to remove an IPA clock reference.  If this represents the
+ * last reference, disable the IPA clock.
+ */
+int ipa_clock_put(struct ipa *ipa)
+{
+	return pm_runtime_put(&ipa->pdev->dev);
 }
 
 /* Return the current IPA core clock rate */
@@ -271,6 +287,40 @@ u32 ipa_clock_rate(struct ipa *ipa)
 	return ipa->clock ? (u32)clk_get_rate(ipa->clock->core) : 0;
 }
 
+/**
+ * ipa_suspend_handler() - Handle the suspend IPA interrupt
+ * @ipa:	IPA pointer
+ * @irq_id:	IPA interrupt type (unused)
+ *
+ * If an RX endpoint is suspended, and the IPA has a packet destined for
+ * that endpoint, the IPA generates a SUSPEND interrupt to inform the AP
+ * that it should resume the endpoint.  If we get one of these interrupts
+ * we just wake up the system.
+ */
+static void ipa_suspend_handler(struct ipa *ipa, enum ipa_irq_id irq_id)
+{
+	/* Just report the event, and let system resume handle the rest.
+	 * More than one endpoint could signal this; if so, ignore
+	 * all but the first.
+	 */
+	if (!test_and_set_bit(IPA_POWER_FLAG_RESUMED, ipa->clock->flags))
+		pm_wakeup_dev_event(&ipa->pdev->dev, 0, true);
+
+	/* Acknowledge/clear the suspend interrupt on all endpoints */
+	ipa_interrupt_suspend_clear_all(ipa->interrupt);
+}
+
+void ipa_power_setup(struct ipa *ipa)
+{
+	ipa_interrupt_add(ipa->interrupt, IPA_IRQ_TX_SUSPEND,
+			  ipa_suspend_handler);
+}
+
+void ipa_power_teardown(struct ipa *ipa)
+{
+	ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_TX_SUSPEND);
+}
+
 /* Initialize IPA clocking */
 struct ipa_clock *
 ipa_clock_init(struct device *dev, const struct ipa_clock_data *data)
@@ -298,6 +348,7 @@ 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;
 
@@ -305,8 +356,8 @@ ipa_clock_init(struct device *dev, const struct ipa_clock_data *data)
 	if (ret)
 		goto err_kfree;
 
-	mutex_init(&clock->mutex);
-	refcount_set(&clock->count, 0);
+	pm_runtime_dont_use_autosuspend(dev);
+	pm_runtime_enable(dev);
 
 	return clock;
 
@@ -323,9 +374,16 @@ void ipa_clock_exit(struct ipa_clock *clock)
 {
 	struct clk *clk = clock->core;
 
-	WARN_ON(refcount_read(&clock->count) != 0);
-	mutex_destroy(&clock->mutex);
+	pm_runtime_disable(clock->dev);
 	ipa_interconnect_exit(clock);
 	kfree(clock);
 	clk_put(clk);
 }
+
+const struct dev_pm_ops ipa_pm_ops = {
+	.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,
+};