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>

During 4.14 rebase added pm_runtime_get_sync/pm_runtime_put around
the reading of LPI2C_PARAM.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
(Vipul: Fixed merge conflicts)
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>

drivers/i2c/busses/i2c-imx-lpi2c.c

@@ -584,7 +584,8 @@ 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);
@@ -594,35 +595,26 @@ 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_enable(lpi2c_imx->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "clk enable failed %d\n", ret);
-		return ret;
-	}
-
 	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
 	pm_runtime_use_autosuspend(&pdev->dev);
-	pm_runtime_get_noresume(&pdev->dev);
-	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
+	pm_runtime_get_sync(&pdev->dev);
 	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
 	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
 	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
 
+	pm_runtime_put(&pdev->dev);
+
 	ret = i2c_add_adapter(&lpi2c_imx->adapter);
 	if (ret)
 		goto rpm_disable;
 
-	pm_runtime_mark_last_busy(&pdev->dev);
-	pm_runtime_put_autosuspend(&pdev->dev);
-
 	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
 
 	return 0;
 
 rpm_disable:
-	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 
@@ -646,8 +638,9 @@ static int lpi2c_runtime_suspend(struct device *dev)
 {
 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
 
-	clk_disable_unprepare(lpi2c_imx->clk);
-	pinctrl_pm_select_sleep_state(dev);
+	clk_disable_unprepare(lpi2c_imx->clk_ipg);
+	clk_disable_unprepare(lpi2c_imx->clk_per);
+	pinctrl_pm_select_idle_state(dev);
 
 	return 0;
 }
@@ -658,18 +651,42 @@ static int lpi2c_runtime_resume(struct device *dev)
 	int ret;
 
 	pinctrl_pm_select_default_state(dev);
-	ret = clk_prepare_enable(lpi2c_imx->clk);
+	ret = clk_prepare_enable(lpi2c_imx->clk_per);
 	if (ret) {
-		dev_err(dev, "failed to enable I2C clock, ret=%d\n", 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 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(pm_runtime_force_suspend,
-				      pm_runtime_force_resume)
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(lpi2c_suspend_noirq,
+				     lpi2c_resume_noirq)
 	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
 			   lpi2c_runtime_resume, NULL)
 };