[PATCH 1/6] mtd: nand: gpmi: add gpmi dsm supend/resume support

From: Han Xu
Date: Tue Jul 28 2015 - 13:57:51 EST


From: Huang Shijie <b32955@xxxxxxxxxxxxx>

i.MX6SX supports deep sleep mode(DSM) that may turn off GPMI/BCH power
during suspend, add gpmi nand suspend/resume function to release DMA
channel in suspend function and re-init GPMI/BCH controller during
resume function.

Although it is not necessary to restore GPMI/BCH registers value for
i.MX6QDL, the code doesn't distinguish different platforms to keep the
code simple.

Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx>
Signed-off-by: Han Xu <han.xu@xxxxxxxxxxxxx>
---
drivers/mtd/nand/gpmi-nand/gpmi-nand.c | 45 +++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
index 1b8f350..dfd0ba1 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
@@ -1,7 +1,7 @@
/*
* Freescale GPMI NAND Flash Driver
*
- * Copyright (C) 2010-2011 Freescale Semiconductor, Inc.
+ * Copyright (C) 2010-2015 Freescale Semiconductor, Inc.
* Copyright (C) 2008 Embedded Alley Solutions, Inc.
*
* This program is free software; you can redistribute it and/or modify
@@ -2036,9 +2036,52 @@ static int gpmi_nand_remove(struct platform_device *pdev)
return 0;
}

+static int gpmi_pm_suspend(struct device *dev)
+{
+ struct gpmi_nand_data *this = dev_get_drvdata(dev);
+
+ release_dma_channels(this);
+ return 0;
+}
+
+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)
+ return ret;
+
+ /* re-init the GPMI registers */
+ this->flags &= ~GPMI_TIMING_INIT_OK;
+ ret = gpmi_init(this);
+ if (ret) {
+ dev_err(this->dev, "Error setting GPMI : %d\n", ret);
+ return ret;
+ }
+
+ /* re-init the BCH registers */
+ ret = bch_set_geometry(this);
+ if (ret) {
+ dev_err(this->dev, "Error setting BCH : %d\n", ret);
+ return ret;
+ }
+
+ /* re-init others */
+ gpmi_extra_init(this);
+
+ return 0;
+}
+
+static const struct dev_pm_ops gpmi_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(gpmi_pm_suspend, gpmi_pm_resume)
+};
+
static struct platform_driver gpmi_nand_driver = {
.driver = {
.name = "gpmi-nand",
+ .pm = &gpmi_pm_ops,
.of_match_table = gpmi_nand_id_table,
},
.probe = gpmi_nand_probe,
--
1.9.1

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