[PATCH v7 21/37] mtd: rawnand: tegra: Add runtime PM support

[Dmitry Osipenko <digetx@xxxxxxxxx>]

The NAND on Tegra belongs to the core power domain and we're going to
enable GENPD support for the core domain. Now NAND must be resumed using
runtime PM API in order to initialize the NAND power state. Add runtime PM
support to the NAND driver.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
 drivers/mtd/nand/raw/tegra_nand.c | 44 ++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/raw/tegra_nand.c b/drivers/mtd/nand/raw/tegra_nand.c
index fbf67722a049..044c7143af7a 100644
--- a/drivers/mtd/nand/raw/tegra_nand.c
+++ b/drivers/mtd/nand/raw/tegra_nand.c
@@ -17,6 +17,7 @@
 #include <linux/mtd/rawnand.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 
 #define COMMAND					0x00
@@ -1152,6 +1153,7 @@ static int tegra_nand_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	ctrl->dev = &pdev->dev;
+	platform_set_drvdata(pdev, ctrl);
 	nand_controller_init(&ctrl->controller);
 	ctrl->controller.ops = &tegra_nand_controller_ops;
 
@@ -1168,14 +1170,15 @@ static int tegra_nand_probe(struct platform_device *pdev)
 	if (IS_ERR(ctrl->clk))
 		return PTR_ERR(ctrl->clk);
 
-	err = clk_prepare_enable(ctrl->clk);
+	pm_runtime_enable(ctrl->dev);
+	err = pm_runtime_resume_and_get(ctrl->dev);
 	if (err)
-		return err;
+		goto err_disable_pm;
 
 	err = reset_control_reset(rst);
 	if (err) {
 		dev_err(ctrl->dev, "Failed to reset HW: %d\n", err);
-		goto err_disable_clk;
+		goto err_put_pm;
 	}
 
 	writel_relaxed(HWSTATUS_CMD_DEFAULT, ctrl->regs + HWSTATUS_CMD);
@@ -1190,21 +1193,21 @@ static int tegra_nand_probe(struct platform_device *pdev)
 			       dev_name(&pdev->dev), ctrl);
 	if (err) {
 		dev_err(ctrl->dev, "Failed to get IRQ: %d\n", err);
-		goto err_disable_clk;
+		goto err_put_pm;
 	}
 
 	writel_relaxed(DMA_MST_CTRL_IS_DONE, ctrl->regs + DMA_MST_CTRL);
 
 	err = tegra_nand_chips_init(ctrl->dev, ctrl);
 	if (err)
-		goto err_disable_clk;
-
-	platform_set_drvdata(pdev, ctrl);
+		goto err_put_pm;
 
 	return 0;
 
-err_disable_clk:
-	clk_disable_unprepare(ctrl->clk);
+err_put_pm:
+	pm_runtime_put(ctrl->dev);
+err_disable_pm:
+	pm_runtime_disable(ctrl->dev);
 	return err;
 }
 
@@ -1221,11 +1224,33 @@ static int tegra_nand_remove(struct platform_device *pdev)
 
 	nand_cleanup(chip);
 
+	pm_runtime_put(ctrl->dev);
+	pm_runtime_disable(ctrl->dev);
+
+	return 0;
+}
+
+static int __maybe_unused tegra_nand_runtime_resume(struct device *dev)
+{
+	struct tegra_nand_controller *ctrl = dev_get_drvdata(dev);
+
+	return clk_prepare_enable(ctrl->clk);
+}
+
+static int __maybe_unused tegra_nand_runtime_suspend(struct device *dev)
+{
+	struct tegra_nand_controller *ctrl = dev_get_drvdata(dev);
+
 	clk_disable_unprepare(ctrl->clk);
 
 	return 0;
 }
 
+static const struct dev_pm_ops tegra_nand_pm = {
+	SET_RUNTIME_PM_OPS(tegra_nand_runtime_suspend, tegra_nand_runtime_resume,
+			   NULL)
+};
+
 static const struct of_device_id tegra_nand_of_match[] = {
 	{ .compatible = "nvidia,tegra20-nand" },
 	{ /* sentinel */ }
@@ -1236,6 +1261,7 @@ static struct platform_driver tegra_nand_driver = {
 	.driver = {
 		.name = "tegra-nand",
 		.of_match_table = tegra_nand_of_match,
+		.pm = &tegra_nand_pm,
 	},
 	.probe = tegra_nand_probe,
 	.remove = tegra_nand_remove,
-- 
2.30.2