MLK-16713 i2c: imx-lpi2c: add runtime pm support

- Add runtime pm support to dynamicly manage the ipg and per clocks.
- Put the suspend to suspend_noirq.
- Call .pm_runtime_force_suspend() to force runtime pm suspended
  in .suspend_noirq().

BuildInfo:
  - SCFW 88456c73, IMX-MKIMAGE 06bc2767, ATF a438801
  - U-Boot 2017.03-imx_v2017.03_4.9.51_imx8_beta1+g7953d47

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Reviewed-by: Anson Huang <Anson.Huang@nxp.com>

1 files changed, 69 insertions, 38 deletions

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index 1bf93d7dba19..f7491ea26cde 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -29,6 +29,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 
@@ -92,6 +93,8 @@
 #define FAST_PLUS_MAX_BITRATE	3400000
 #define HIGHSPEED_MAX_BITRATE	5000000
 
+#define I2C_PM_TIMEOUT		10 /* ms */
+
 enum lpi2c_imx_mode {
 	STANDARD,	/* 100+Kbps */
 	FAST,		/* 400+Kbps */
@@ -275,15 +278,9 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 	unsigned int temp;
 	int ret;
 
-	ret = clk_enable(lpi2c_imx->clk_ipg);
-	if (ret)
-		return ret;
-
-	ret = clk_enable(lpi2c_imx->clk_per);
-	if (ret) {
-		clk_disable(lpi2c_imx->clk_ipg);
+	ret = pm_runtime_get_sync(lpi2c_imx->adapter.dev.parent);
+	if (ret < 0)
 		return ret;
-	}
 
 	temp = MCR_RST;
 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
@@ -291,7 +288,7 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 
 	ret = lpi2c_imx_config(lpi2c_imx);
 	if (ret)
-		goto clk_disable;
+		goto rpm_put;
 
 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
 	temp |= MCR_MEN;
@@ -299,9 +296,9 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 
 	return 0;
 
-clk_disable:
-	clk_disable(lpi2c_imx->clk_per);
-	clk_disable(lpi2c_imx->clk_ipg);
+rpm_put:
+	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
+	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
 
 	return ret;
 }
@@ -314,8 +311,8 @@ static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
 	temp &= ~MCR_MEN;
 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
 
-	clk_disable(lpi2c_imx->clk_per);
-	clk_disable(lpi2c_imx->clk_ipg);
+	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
+	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
 
 	return 0;
 }
@@ -606,7 +603,8 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
 	if (ret)
 		lpi2c_imx->bitrate = LPI2C_DEFAULT_RATE;
 
-	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
+	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr,
+			       IRQF_NO_SUSPEND,
 			       pdev->name, lpi2c_imx);
 	if (ret) {
 		dev_err(&pdev->dev, "can't claim irq %d\n", irq);
@@ -616,30 +614,21 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
 	i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
 	platform_set_drvdata(pdev, lpi2c_imx);
 
-	ret = clk_prepare(lpi2c_imx->clk_per);
-	if (ret) {
-		dev_err(&pdev->dev, "clk prepare failed %d\n", ret);
-		return ret;
-	}
-
-	ret = clk_prepare(lpi2c_imx->clk_ipg);
-	if (ret) {
-		clk_unprepare(lpi2c_imx->clk_per);
-		dev_err(&pdev->dev, "clk prepare failed %d\n", ret);
-		return ret;
-	}
+	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
 
 	ret = i2c_add_adapter(&lpi2c_imx->adapter);
 	if (ret)
-		goto clk_unprepare;
+		goto rpm_disable;
 
 	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
 
 	return 0;
 
-clk_unprepare:
-	clk_unprepare(lpi2c_imx->clk_ipg);
-	clk_unprepare(lpi2c_imx->clk_per);
+rpm_disable:
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 
 	return ret;
 }
@@ -650,27 +639,69 @@ static int lpi2c_imx_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&lpi2c_imx->adapter);
 
-	clk_unprepare(lpi2c_imx->clk_ipg);
-	clk_unprepare(lpi2c_imx->clk_per);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 
 	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
-static int lpi2c_imx_suspend(struct device *dev)
+static int lpi2c_runtime_suspend(struct device *dev)
 {
-	pinctrl_pm_select_sleep_state(dev);
+	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(lpi2c_imx->clk_ipg);
+	clk_disable_unprepare(lpi2c_imx->clk_per);
+	pinctrl_pm_select_idle_state(dev);
+
 	return 0;
 }
 
-static int lpi2c_imx_resume(struct device *dev)
+static int lpi2c_runtime_resume(struct device *dev)
 {
+	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
+	int ret;
+
 	pinctrl_pm_select_default_state(dev);
+	ret = clk_prepare_enable(lpi2c_imx->clk_per);
+	if (ret) {
+		dev_err(dev, "can't enable I2C per clock, ret=%d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(lpi2c_imx->clk_ipg);
+	if (ret) {
+		clk_disable_unprepare(lpi2c_imx->clk_per);
+		dev_err(dev, "can't enable I2C ipg clock, ret=%d\n", ret);
+	}
+
+	return ret;
+}
+
+static int lpi2c_suspend_noirq(struct device *dev)
+{
+	int ret;
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret)
+		return ret;
+
+	pinctrl_pm_select_sleep_state(dev);
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(imx_lpi2c_pm, lpi2c_imx_suspend, lpi2c_imx_resume);
-#define IMX_LPI2C_PM      (&imx_lpi2c_pm)
+static int lpi2c_resume_noirq(struct device *dev)
+{
+	return pm_runtime_force_resume(dev);
+}
+
+static const struct dev_pm_ops lpi2c_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(lpi2c_suspend_noirq,
+				     lpi2c_resume_noirq)
+	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
+			   lpi2c_runtime_resume, NULL)
+};
+#define IMX_LPI2C_PM      (&lpi2c_pm_ops)
 #else
 #define IMX_LPI2C_PM      NULL
 #endif