[PATCH] mtd: rawnand: gpmi: fix the suspend/resume issue

[Han Xu <han.xu@xxxxxxx>]

fix several issues when system suspend/resume,

- leverage the runtime pm for system suspend/resume
- enable the clock before register access
- re-apply timing settings
- set the proper pinctrl state

Signed-off-by: Han Xu <han.xu@xxxxxxx>
---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 59 ++++++++++++++++------
 1 file changed, 44 insertions(+), 15 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index 334fe3130285..37437d47ab9a 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -15,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/dma/mxs-dma.h>
 #include "gpmi-nand.h"
 #include "gpmi-regs.h"
@@ -146,7 +147,11 @@ static int __gpmi_enable_clk(struct gpmi_nand_data *this, bool v)
 static int gpmi_init(struct gpmi_nand_data *this)
 {
 	struct resources *r = &this->resources;
-	int ret;
+	int ret = 0;
+
+	ret = pm_runtime_get_sync(this->dev);
+	if (ret < 0)
+		return ret;
 
 	ret = gpmi_reset_block(r->gpmi_regs, false);
 	if (ret)
@@ -179,8 +184,10 @@ static int gpmi_init(struct gpmi_nand_data *this)
 	 */
 	writel(BM_GPMI_CTRL1_DECOUPLE_CS, r->gpmi_regs + HW_GPMI_CTRL1_SET);
 
-	return 0;
 err_out:
+	pm_runtime_mark_last_busy(this->dev);
+	pm_runtime_put_autosuspend(this->dev);
+
 	return ret;
 }
 
@@ -528,7 +535,7 @@ static int common_nfc_set_geometry(struct gpmi_nand_data *this)
 static int bch_set_geometry(struct gpmi_nand_data *this)
 {
 	struct resources *r = &this->resources;
-	int ret;
+	int ret = 0;
 
 	ret = common_nfc_set_geometry(this);
 	if (ret)
@@ -550,7 +557,6 @@ static int bch_set_geometry(struct gpmi_nand_data *this)
 	/* Set *all* chip selects to use layout 0. */
 	writel(0, r->bch_regs + HW_BCH_LAYOUTSELECT);
 
-	ret = 0;
 err_out:
 	pm_runtime_mark_last_busy(this->dev);
 	pm_runtime_put_autosuspend(this->dev);
@@ -2676,7 +2682,7 @@ static int gpmi_nand_probe(struct platform_device *pdev)
 	return 0;
 
 exit_nfc_init:
-	pm_runtime_put(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	release_resources(this);
 exit_acquire_resources:
@@ -2688,7 +2694,6 @@ static int gpmi_nand_remove(struct platform_device *pdev)
 {
 	struct gpmi_nand_data *this = platform_get_drvdata(pdev);
 
-	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
 	nand_release(&this->nand);
@@ -2700,10 +2705,12 @@ static int gpmi_nand_remove(struct platform_device *pdev)
 #ifdef CONFIG_PM_SLEEP
 static int gpmi_pm_suspend(struct device *dev)
 {
-	struct gpmi_nand_data *this = dev_get_drvdata(dev);
+	int ret;
 
-	release_dma_channels(this);
-	return 0;
+	pinctrl_pm_select_sleep_state(dev);
+	ret = pm_runtime_force_suspend(dev);
+
+	return ret;
 }
 
 static int gpmi_pm_resume(struct device *dev)
@@ -2711,9 +2718,13 @@ static int gpmi_pm_resume(struct device *dev)
 	struct gpmi_nand_data *this = dev_get_drvdata(dev);
 	int ret;
 
-	ret = acquire_dma_channels(this);
-	if (ret < 0)
+	ret = pm_runtime_force_resume(dev);
+	if (ret) {
+		dev_err(this->dev, "Error in resume %d\n", ret);
 		return ret;
+	}
+
+	pinctrl_pm_select_default_state(dev);
 
 	/* re-init the GPMI registers */
 	ret = gpmi_init(this);
@@ -2729,22 +2740,40 @@ static int gpmi_pm_resume(struct device *dev)
 		return ret;
 	}
 
+	/* re-apply the timing setting */
+	this->hw.must_apply_timings = true;
+
 	return 0;
 }
 #endif /* CONFIG_PM_SLEEP */
 
-static int __maybe_unused gpmi_runtime_suspend(struct device *dev)
+#define gpmi_enable_clk(x)	__gpmi_enable_clk(x, true)
+#define gpmi_disable_clk(x)	__gpmi_enable_clk(x, false)
+
+static int gpmi_runtime_suspend(struct device *dev)
 {
 	struct gpmi_nand_data *this = dev_get_drvdata(dev);
 
-	return __gpmi_enable_clk(this, false);
+	gpmi_disable_clk(this);
+	release_dma_channels(this);
+
+	return 0;
 }
 
-static int __maybe_unused gpmi_runtime_resume(struct device *dev)
+static int gpmi_runtime_resume(struct device *dev)
 {
 	struct gpmi_nand_data *this = dev_get_drvdata(dev);
+	int ret;
 
-	return __gpmi_enable_clk(this, true);
+	ret = gpmi_enable_clk(this);
+	if (ret)
+		return ret;
+
+	ret = acquire_dma_channels(this);
+	if (ret < 0)
+		return ret;
+
+	return 0;
 }
 
 static const struct dev_pm_ops gpmi_pm_ops = {
-- 
2.17.1


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