[PATCH 1/1] spi: mediatek: add power control when set_cs

[Luhua Xu <luhua.xu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>]

From: "luhua.xu" <luhua.xu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

Use runtime PM to power spi when set_cs
As set_cs may be called from interrupt context,
set runtime PM IRQ safe for spi.

Signed-off-by: luhua.xu <luhua.xu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 drivers/spi/spi-mt65xx.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 6888a4d..039b67d 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -262,8 +262,16 @@ static int mtk_spi_prepare_message(struct spi_master *master,
 static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
 {
 	u32 reg_val;
+	int ret;
 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
 
+	ret = pm_runtime_get_sync(spi->master->dev.parent);
+	if (ret < 0) {
+		pm_runtime_put_noidle(spi->master->dev.parent);
+		dev_err(&spi->dev, "failed to power device(%d)\n", ret);
+		return;
+	}
+
 	reg_val = readl(mdata->base + SPI_CMD_REG);
 	if (!enable) {
 		reg_val |= SPI_CMD_PAUSE_EN;
@@ -274,6 +282,9 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
 		mdata->state = MTK_SPI_IDLE;
 		mtk_spi_reset(mdata);
 	}
+
+	pm_runtime_mark_last_busy(spi->master->dev.parent);
+	pm_runtime_put_autosuspend(spi->master->dev.parent);
 }
 
 static void mtk_spi_prepare_transfer(struct spi_master *master,
@@ -749,6 +760,7 @@ static int mtk_spi_probe(struct platform_device *pdev)
 	clk_disable_unprepare(mdata->spi_clk);
 
 	pm_runtime_enable(&pdev->dev);
+	pm_runtime_irq_safe(&pdev->dev);
 
 	ret = devm_spi_register_master(&pdev->dev, master);
 	if (ret) {
-- 
2.6.4