From 817ba283acf2d7b5aa073b96fd989f336fcff72a Mon Sep 17 00:00:00 2001
From: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>
Date: Fri, 23 Oct 2015 05:50:33 +0200
Subject: merge more stuff from 3.2.72

---
 drivers/amba/bus.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 64 insertions(+), 4 deletions(-)

(limited to 'drivers/amba/bus.c')

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index d74926e..bd230e8 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -365,6 +365,40 @@ static int amba_pm_restore_noirq(struct device *dev)
 
 #endif /* !CONFIG_HIBERNATE_CALLBACKS */
 
+#ifdef CONFIG_PM_RUNTIME
+/*
+ * Hooks to provide runtime PM of the pclk (bus clock).  It is safe to
+ * enable/disable the bus clock at runtime PM suspend/resume as this
+ * does not result in loss of context.  However, disabling vcore power
+ * would do, so we leave that to the driver.
+ */
+static int amba_pm_runtime_suspend(struct device *dev)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	int ret = pm_generic_runtime_suspend(dev);
+
+	if (ret == 0 && dev->driver)
+		clk_disable(pcdev->pclk);
+
+	return ret;
+}
+
+static int amba_pm_runtime_resume(struct device *dev)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	int ret;
+
+	if (dev->driver) {
+		ret = clk_enable(pcdev->pclk);
+		/* Failure is probably fatal to the system, but... */
+		if (ret)
+			return ret;
+	}
+
+	return pm_generic_runtime_resume(dev);
+}
+#endif
+
 #ifdef CONFIG_PM
 
 static const struct dev_pm_ops amba_pm = {
@@ -383,8 +417,8 @@ static const struct dev_pm_ops amba_pm = {
 	.poweroff_noirq	= amba_pm_poweroff_noirq,
 	.restore_noirq	= amba_pm_restore_noirq,
 	SET_RUNTIME_PM_OPS(
-		pm_generic_runtime_suspend,
-		pm_generic_runtime_resume,
+		amba_pm_runtime_suspend,
+		amba_pm_runtime_resume,
 		pm_generic_runtime_idle
 	)
 };
@@ -426,9 +460,17 @@ static int amba_get_enable_pclk(struct amba_device *pcdev)
 	if (IS_ERR(pclk))
 		return PTR_ERR(pclk);
 
+	ret = clk_prepare(pclk);
+	if (ret) {
+		clk_put(pclk);
+		return ret;
+	}
+
 	ret = clk_enable(pclk);
-	if (ret)
+	if (ret) {
+		clk_unprepare(pclk);
 		clk_put(pclk);
+	}
 
 	return ret;
 }
@@ -438,6 +480,7 @@ static void amba_put_disable_pclk(struct amba_device *pcdev)
 	struct clk *pclk = pcdev->pclk;
 
 	clk_disable(pclk);
+	clk_unprepare(pclk);
 	clk_put(pclk);
 }
 
@@ -494,10 +537,18 @@ static int amba_probe(struct device *dev)
 		if (ret)
 			break;
 
+		pm_runtime_get_noresume(dev);
+		pm_runtime_set_active(dev);
+		pm_runtime_enable(dev);
+
 		ret = pcdrv->probe(pcdev, id);
 		if (ret == 0)
 			break;
 
+		pm_runtime_disable(dev);
+		pm_runtime_set_suspended(dev);
+		pm_runtime_put_noidle(dev);
+
 		amba_put_disable_pclk(pcdev);
 		amba_put_disable_vcore(pcdev);
 	} while (0);
@@ -509,7 +560,16 @@ static int amba_remove(struct device *dev)
 {
 	struct amba_device *pcdev = to_amba_device(dev);
 	struct amba_driver *drv = to_amba_driver(dev->driver);
-	int ret = drv->remove(pcdev);
+	int ret;
+
+	pm_runtime_get_sync(dev);
+	ret = drv->remove(pcdev);
+	pm_runtime_put_noidle(dev);
+
+	/* Undo the runtime PM settings in amba_probe() */
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
 
 	amba_put_disable_pclk(pcdev);
 	amba_put_disable_vcore(pcdev);
-- 
cgit v1.1