1 files changed, 81 insertions, 23 deletions

diff --git a/drivers/i2c/busses/i2c-img-scb.c b/drivers/i2c/busses/i2c-img-scb.c
index eb1d91b986fd..f038858b6c54 100644
--- a/drivers/i2c/busses/i2c-img-scb.c
+++ b/drivers/i2c/busses/i2c-img-scb.c
@@ -82,6 +82,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/timer.h>
 
@@ -280,6 +281,8 @@
 #define ISR_COMPLETE(err)	(ISR_COMPLETE_M | (ISR_STATUS_M & (err)))
 #define ISR_FATAL(err)		(ISR_COMPLETE(err) | ISR_FATAL_M)
 
+#define IMG_I2C_PM_TIMEOUT	1000 /* ms */
+
 enum img_i2c_mode {
 	MODE_INACTIVE,
 	MODE_RAW,
@@ -408,6 +411,9 @@ struct img_i2c {
 	unsigned int raw_timeout;
 };
 
+static int img_i2c_runtime_suspend(struct device *dev);
+static int img_i2c_runtime_resume(struct device *dev);
+
 static void img_i2c_writel(struct img_i2c *i2c, u32 offset, u32 value)
 {
 	writel(value, i2c->base + offset);
@@ -826,9 +832,9 @@ next_atomic_cmd:
  * Timer function to check if something has gone wrong in automatic mode (so we
  * don't have to handle so many interrupts just to catch an exception).
  */
-static void img_i2c_check_timer(unsigned long arg)
+static void img_i2c_check_timer(struct timer_list *t)
 {
-	struct img_i2c *i2c = (struct img_i2c *)arg;
+	struct img_i2c *i2c = from_timer(i2c, t, check_timer);
 	unsigned long flags;
 	unsigned int line_status;
 
@@ -1054,8 +1060,8 @@ static int img_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			atomic = true;
 	}
 
-	ret = clk_prepare_enable(i2c->scb_clk);
-	if (ret)
+	ret = pm_runtime_get_sync(adap->dev.parent);
+	if (ret < 0)
 		return ret;
 
 	for (i = 0; i < num; i++) {
@@ -1131,7 +1137,8 @@ static int img_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			break;
 	}
 
-	clk_disable_unprepare(i2c->scb_clk);
+	pm_runtime_mark_last_busy(adap->dev.parent);
+	pm_runtime_put_autosuspend(adap->dev.parent);
 
 	return i2c->msg_status ? i2c->msg_status : num;
 }
@@ -1149,12 +1156,13 @@ static const struct i2c_algorithm img_i2c_algo = {
 static int img_i2c_init(struct img_i2c *i2c)
 {
 	unsigned int clk_khz, bitrate_khz, clk_period, tckh, tckl, tsdh;
-	unsigned int i, ret, data, prescale, inc, int_bitrate, filt;
+	unsigned int i, data, prescale, inc, int_bitrate, filt;
 	struct img_i2c_timings timing;
 	u32 rev;
+	int ret;
 
-	ret = clk_prepare_enable(i2c->scb_clk);
-	if (ret)
+	ret = pm_runtime_get_sync(i2c->adap.dev.parent);
+	if (ret < 0)
 		return ret;
 
 	rev = img_i2c_readl(i2c, SCB_CORE_REV_REG);
@@ -1163,7 +1171,8 @@ static int img_i2c_init(struct img_i2c *i2c)
 			 "Unknown hardware revision (%d.%d.%d.%d)\n",
 			 (rev >> 24) & 0xff, (rev >> 16) & 0xff,
 			 (rev >> 8) & 0xff, rev & 0xff);
-		clk_disable_unprepare(i2c->scb_clk);
+		pm_runtime_mark_last_busy(i2c->adap.dev.parent);
+		pm_runtime_put_autosuspend(i2c->adap.dev.parent);
 		return -EINVAL;
 	}
 
@@ -1314,7 +1323,8 @@ static int img_i2c_init(struct img_i2c *i2c)
 	/* Perform a synchronous sequence to reset the bus */
 	ret = img_i2c_reset_bus(i2c);
 
-	clk_disable_unprepare(i2c->scb_clk);
+	pm_runtime_mark_last_busy(i2c->adap.dev.parent);
+	pm_runtime_put_autosuspend(i2c->adap.dev.parent);
 
 	return ret;
 }
@@ -1362,8 +1372,7 @@ static int img_i2c_probe(struct platform_device *pdev)
 	}
 
 	/* Set up the exception check timer */
-	setup_timer(&i2c->check_timer, img_i2c_check_timer,
-		    (unsigned long)i2c);
+	timer_setup(&i2c->check_timer, img_i2c_check_timer, 0);
 
 	i2c->bitrate = timings[0].max_bitrate;
 	if (!of_property_read_u32(node, "clock-frequency", &val))
@@ -1384,22 +1393,30 @@ static int img_i2c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, i2c);
 
-	ret = clk_prepare_enable(i2c->sys_clk);
-	if (ret)
-		return ret;
+	pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = img_i2c_runtime_resume(&pdev->dev);
+		if (ret)
+			return ret;
+	}
 
 	ret = img_i2c_init(i2c);
 	if (ret)
-		goto disable_clk;
+		goto rpm_disable;
 
 	ret = i2c_add_numbered_adapter(&i2c->adap);
 	if (ret < 0)
-		goto disable_clk;
+		goto rpm_disable;
 
 	return 0;
 
-disable_clk:
-	clk_disable_unprepare(i2c->sys_clk);
+rpm_disable:
+	if (!pm_runtime_enabled(&pdev->dev))
+		img_i2c_runtime_suspend(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	return ret;
 }
 
@@ -1408,19 +1425,55 @@ static int img_i2c_remove(struct platform_device *dev)
 	struct img_i2c *i2c = platform_get_drvdata(dev);
 
 	i2c_del_adapter(&i2c->adap);
+	pm_runtime_disable(&dev->dev);
+	if (!pm_runtime_status_suspended(&dev->dev))
+		img_i2c_runtime_suspend(&dev->dev);
+
+	return 0;
+}
+
+static int img_i2c_runtime_suspend(struct device *dev)
+{
+	struct img_i2c *i2c = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(i2c->scb_clk);
 	clk_disable_unprepare(i2c->sys_clk);
 
 	return 0;
 }
 
+static int img_i2c_runtime_resume(struct device *dev)
+{
+	struct img_i2c *i2c = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(i2c->sys_clk);
+	if (ret) {
+		dev_err(dev, "Unable to enable sys clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(i2c->scb_clk);
+	if (ret) {
+		dev_err(dev, "Unable to enable scb clock\n");
+		clk_disable_unprepare(i2c->sys_clk);
+		return ret;
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int img_i2c_suspend(struct device *dev)
 {
 	struct img_i2c *i2c = dev_get_drvdata(dev);
+	int ret;
 
-	img_i2c_switch_mode(i2c, MODE_SUSPEND);
+	ret = pm_runtime_force_suspend(dev);
+	if (ret)
+		return ret;
 
-	clk_disable_unprepare(i2c->sys_clk);
+	img_i2c_switch_mode(i2c, MODE_SUSPEND);
 
 	return 0;
 }
@@ -1430,7 +1483,7 @@ static int img_i2c_resume(struct device *dev)
 	struct img_i2c *i2c = dev_get_drvdata(dev);
 	int ret;
 
-	ret = clk_prepare_enable(i2c->sys_clk);
+	ret = pm_runtime_force_resume(dev);
 	if (ret)
 		return ret;
 
@@ -1440,7 +1493,12 @@ static int img_i2c_resume(struct device *dev)
 }
 #endif /* CONFIG_PM_SLEEP */
 
-static SIMPLE_DEV_PM_OPS(img_i2c_pm, img_i2c_suspend, img_i2c_resume);
+static const struct dev_pm_ops img_i2c_pm = {
+	SET_RUNTIME_PM_OPS(img_i2c_runtime_suspend,
+			   img_i2c_runtime_resume,
+			   NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(img_i2c_suspend, img_i2c_resume)
+};
 
 static const struct of_device_id img_scb_i2c_match[] = {
 	{ .compatible = "img,scb-i2c" },