Subject: [PATCH 5/6] mtd: rawnand: gpmi: refine the runtime pm ops

From: Han Xu <[email-masked]>
Date: Wed, 15 Jan 2020 05:44:02 +0800

several changes for runtime code in gpmi-nand driver

- Always invoke runtime get/put in same function to balance the usage
counter.

- leverage the runtime pm for system pm, move acquire dma to runtime pm
to acquire dma only when needed.

- add pm_runtime_dont_use_autosuspend in err path. If driver failed to
probe before runtime pm timeout, such as NAND not mounted in socket,
runtime suspend won't be called without the change.

Signed-off-by: Han Xu <[email-masked]>
---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 56 +++++++++++-----------
 1 file changed, 29 insertions(+), 27 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index fcc7325f2a10..73644c96fa9b 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -183,7 +183,6 @@ 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);
@@ -556,7 +555,6 @@ 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);
@@ -1213,10 +1211,6 @@ static int acquire_resources(struct gpmi_nand_data *this)
 	if (ret)
 		goto exit_regs;
 
-	ret = acquire_dma_channels(this);
-	if (ret)
-		goto exit_regs;
-
 	ret = gpmi_get_clks(this);
 	if (ret)
 		goto exit_clock;
@@ -2656,15 +2650,9 @@ static int gpmi_nand_probe(struct platform_device *pdev)
 	if (ret)
 		goto exit_acquire_resources;
 
-	ret = __gpmi_enable_clk(this, true);
-	if (ret)
-		goto exit_nfc_init;
-
+	pm_runtime_enable(&pdev->dev);
 	pm_runtime_set_autosuspend_delay(&pdev->dev, 500);
 	pm_runtime_use_autosuspend(&pdev->dev);
-	pm_runtime_set_active(&pdev->dev);
-	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(&pdev->dev);
 
 	ret = gpmi_init(this);
 	if (ret)
@@ -2674,15 +2662,12 @@ static int gpmi_nand_probe(struct platform_device *pdev)
 	if (ret)
 		goto exit_nfc_init;
 
-	pm_runtime_mark_last_busy(&pdev->dev);
-	pm_runtime_put_autosuspend(&pdev->dev);
-
 	dev_info(this->dev, "driver registered.\n");
 
 	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:
@@ -2694,7 +2679,6 @@ 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);
@@ -2706,10 +2690,11 @@ 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;
+	ret = pm_runtime_force_suspend(dev);
+
+	return ret;
 }
 
 static int gpmi_pm_resume(struct device *dev)
@@ -2717,9 +2702,11 @@ 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;
+	}
 
 	/* re-init the GPMI registers */
 	ret = gpmi_init(this);
@@ -2743,18 +2730,33 @@ static int gpmi_pm_resume(struct device *dev)
 }
 #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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