i2c: tegra: use PM runtime framework

Convert tegra i2c driver to use PM runtime framework.

changes since last version:

fix hang when using resume_noirq

Change-Id: I1cce314ef4c06dbc7f1b3ddbdd1ad50255aa8b02
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Reviewed-on: http://git-master/r/71192
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Varun Wadekar <vwadekar@nvidia.com>

1 files changed, 47 insertions, 25 deletions

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 2cbee05c3897..2d058369a6fd 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -33,6 +33,7 @@
 #include <linux/i2c-tegra.h>
 #include <linux/of_i2c.h>
 #include <linux/spinlock.h>
+#include <linux/pm_runtime.h>
 
 #include <asm/unaligned.h>
 
@@ -112,8 +113,6 @@
 #define SL_ADDR1(addr) (addr & 0xff)
 #define SL_ADDR2(addr) ((addr >> 8) & 0xff)
 
-
-
 struct tegra_i2c_dev;
 
 struct tegra_i2c_bus {
@@ -396,8 +395,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 	u32 val;
 	int err = 0;
 
-	if (!i2c_dev->is_clkon_always)
-		clk_enable(i2c_dev->clk);
+	pm_runtime_get_sync(i2c_dev->dev);
 
 	/* Interrupt generated before sending stop signal so
 	* wait for some time so that stop signal can be send proerly */
@@ -435,8 +433,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 	if (tegra_i2c_flush_fifos(i2c_dev))
 		err = -ETIMEDOUT;
 
-	if (!i2c_dev->is_clkon_always)
-		clk_disable(i2c_dev->clk);
+	pm_runtime_put_sync(i2c_dev->dev);
 
 	if (i2c_dev->irq_disabled) {
 		i2c_dev->irq_disabled = 0;
@@ -693,8 +690,10 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
 	int ret = 0;
 	unsigned long flags;
 
-	if (i2c_dev->is_suspended)
-		return -EBUSY;
+	if (i2c_dev->is_suspended) {
+		tegra_i2c_init(i2c_dev);
+		i2c_dev->is_suspended = false;
+	}
 
 	rt_mutex_lock(&i2c_dev->dev_lock);
 
@@ -715,8 +714,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
 	i2c_dev->msgs = msgs;
 	i2c_dev->msgs_num = num;
 
-	if (!i2c_dev->is_clkon_always)
-		clk_enable(i2c_dev->clk);
+	pm_runtime_get_sync(i2c_dev->dev);
 
 	spin_lock_irqsave(&i2c_dev->clk_lock, flags);
 	i2c_dev->controller_enabled = true;
@@ -733,8 +731,7 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
 	i2c_dev->controller_enabled = false;
 	spin_unlock_irqrestore(&i2c_dev->clk_lock, flags);
 
-	if (!i2c_dev->is_clkon_always)
-		clk_disable(i2c_dev->clk);
+	pm_runtime_put_sync(i2c_dev->dev);
 
 	rt_mutex_unlock(&i2c_dev->dev_lock);
 
@@ -856,8 +853,8 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, i2c_dev);
 
-	if (i2c_dev->is_clkon_always)
-		clk_enable(i2c_dev->clk);
+	pm_runtime_enable(i2c_dev->dev);
+	pm_runtime_irq_safe(i2c_dev->dev);
 
 	ret = tegra_i2c_init(i2c_dev);
 	if (ret) {
@@ -865,6 +862,9 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 		goto err_free;
 	}
 
+	if (i2c_dev->is_clkon_always)
+		pm_runtime_forbid(i2c_dev->dev);
+
 	ret = request_irq(i2c_dev->irq, tegra_i2c_isr, 0, pdev->name, i2c_dev);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
@@ -935,7 +935,9 @@ static int tegra_i2c_remove(struct platform_device *pdev)
 		i2c_del_adapter(&i2c_dev->busses[i2c_dev->bus_count].adapter);
 
 	if (i2c_dev->is_clkon_always)
-		clk_disable(i2c_dev->clk);
+		pm_runtime_allow(i2c_dev->dev);
+
+	pm_runtime_disable(i2c_dev->dev);
 
 	free_irq(i2c_dev->irq, i2c_dev);
 	clk_put(i2c_dev->clk);
@@ -956,7 +958,7 @@ static int tegra_i2c_suspend_noirq(struct device *dev)
 
 	i2c_dev->is_suspended = true;
 	if (i2c_dev->is_clkon_always)
-		clk_disable(i2c_dev->clk);
+		pm_runtime_allow(i2c_dev->dev);
 
 	rt_mutex_unlock(&i2c_dev->dev_lock);
 
@@ -971,19 +973,36 @@ static int tegra_i2c_resume_noirq(struct device *dev)
 
 	rt_mutex_lock(&i2c_dev->dev_lock);
 
-	if (i2c_dev->is_clkon_always)
-		clk_enable(i2c_dev->clk);
+	if (i2c_dev->is_clkon_always) {
+		pm_runtime_forbid(i2c_dev->dev);
+		ret = tegra_i2c_init(i2c_dev);
+		if (ret) {
+			rt_mutex_unlock(&i2c_dev->dev_lock);
+			return ret;
+		}
+		i2c_dev->is_suspended = false;
+	}
+	rt_mutex_unlock(&i2c_dev->dev_lock);
 
-	ret = tegra_i2c_init(i2c_dev);
+	return 0;
+}
 
-	if (ret) {
-		rt_mutex_unlock(&i2c_dev->dev_lock);
-		return ret;
-	}
+static int tegra_i2c_runtime_idle(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
 
-	i2c_dev->is_suspended = false;
+	clk_disable(i2c_dev->clk);
 
-	rt_mutex_unlock(&i2c_dev->dev_lock);
+	return 0;
+}
+
+static int tegra_i2c_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+	clk_enable(i2c_dev->clk);
 
 	return 0;
 }
@@ -991,7 +1010,10 @@ static int tegra_i2c_resume_noirq(struct device *dev)
 static const struct dev_pm_ops tegra_i2c_dev_pm_ops = {
 	.suspend_noirq = tegra_i2c_suspend_noirq,
 	.resume_noirq = tegra_i2c_resume_noirq,
+	.runtime_idle = tegra_i2c_runtime_idle,
+	.runtime_resume = tegra_i2c_runtime_resume,
 };
+
 #define TEGRA_I2C_DEV_PM_OPS (&tegra_i2c_dev_pm_ops)
 #else
 #define TEGRA_I2C_DEV_PM_OPS NULL