[PATCH v1 2/2] mtd: mtk-nor: add suspend/resume support

From: Guochun Mao
Date: Thu Sep 21 2017 - 08:45:27 EST


Abstract functions of clock setting, to avoid duplicated code,
these functions been used in new feature.
Implement suspend/resume functions.

Signed-off-by: Guochun Mao <guochun.mao@xxxxxxxxxxxx>
---
drivers/mtd/spi-nor/mtk-quadspi.c | 70 ++++++++++++++++++++++++++++++-------
1 file changed, 58 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/spi-nor/mtk-quadspi.c b/drivers/mtd/spi-nor/mtk-quadspi.c
index c258c7a..abe455c 100644
--- a/drivers/mtd/spi-nor/mtk-quadspi.c
+++ b/drivers/mtd/spi-nor/mtk-quadspi.c
@@ -404,6 +404,29 @@ static int mt8173_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
return ret;
}

+static void mt8173_nor_disable_clk(struct mt8173_nor *mt8173_nor)
+{
+ clk_disable_unprepare(mt8173_nor->spi_clk);
+ clk_disable_unprepare(mt8173_nor->nor_clk);
+}
+
+static int mt8173_nor_enable_clk(struct mt8173_nor *mt8173_nor)
+{
+ int ret;
+
+ ret = clk_prepare_enable(mt8173_nor->spi_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(mt8173_nor->nor_clk);
+ if (ret) {
+ clk_disable_unprepare(mt8173_nor->spi_clk);
+ return ret;
+ }
+
+ return 0;
+}
+
static int mtk_nor_init(struct mt8173_nor *mt8173_nor,
struct device_node *flash_node)
{
@@ -468,15 +491,11 @@ static int mtk_nor_drv_probe(struct platform_device *pdev)
return PTR_ERR(mt8173_nor->nor_clk);

mt8173_nor->dev = &pdev->dev;
- ret = clk_prepare_enable(mt8173_nor->spi_clk);
+
+ ret = mt8173_nor_enable_clk(mt8173_nor);
if (ret)
return ret;

- ret = clk_prepare_enable(mt8173_nor->nor_clk);
- if (ret) {
- clk_disable_unprepare(mt8173_nor->spi_clk);
- return ret;
- }
/* only support one attached flash */
flash_np = of_get_next_available_child(pdev->dev.of_node, NULL);
if (!flash_np) {
@@ -487,10 +506,9 @@ static int mtk_nor_drv_probe(struct platform_device *pdev)
ret = mtk_nor_init(mt8173_nor, flash_np);

nor_free:
- if (ret) {
- clk_disable_unprepare(mt8173_nor->spi_clk);
- clk_disable_unprepare(mt8173_nor->nor_clk);
- }
+ if (ret)
+ mt8173_nor_disable_clk(mt8173_nor);
+
return ret;
}

@@ -498,11 +516,38 @@ static int mtk_nor_drv_remove(struct platform_device *pdev)
{
struct mt8173_nor *mt8173_nor = platform_get_drvdata(pdev);

- clk_disable_unprepare(mt8173_nor->spi_clk);
- clk_disable_unprepare(mt8173_nor->nor_clk);
+ mt8173_nor_disable_clk(mt8173_nor);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_nor_suspend(struct device *dev)
+{
+ struct mt8173_nor *mt8173_nor = dev_get_drvdata(dev);
+
+ mt8173_nor_disable_clk(mt8173_nor);
+
return 0;
}

+static int mtk_nor_resume(struct device *dev)
+{
+ struct mt8173_nor *mt8173_nor = dev_get_drvdata(dev);
+
+ return mt8173_nor_enable_clk(mt8173_nor);
+}
+
+static const struct dev_pm_ops mtk_nor_dev_pm_ops = {
+ .suspend = mtk_nor_suspend,
+ .resume = mtk_nor_resume,
+};
+
+#define MTK_NOR_DEV_PM_OPS (&mtk_nor_dev_pm_ops)
+#else
+#define MTK_NOR_DEV_PM_OPS NULL
+#endif
+
static const struct of_device_id mtk_nor_of_ids[] = {
{ .compatible = "mediatek,mt8173-nor"},
{ /* sentinel */ }
@@ -514,6 +559,7 @@ static int mtk_nor_drv_remove(struct platform_device *pdev)
.remove = mtk_nor_drv_remove,
.driver = {
.name = "mtk-nor",
+ .pm = MTK_NOR_DEV_PM_OPS,
.of_match_table = mtk_nor_of_ids,
},
};
--
1.7.9.5