spi: s3c64xx: extend driver to make full use of runtime PM autosuspend

Extend the driver to make full use of runtime PM autosuspend. Before only the SPI core was instructed to use autosuspend by setting master->auto_runtime_pm. Nevertheless due to the missing pm_runtime_use_autosuspend call autosuspend wasn't active.

Signed-off-by Heiner Kallweit <[email protected]>

---
Changed:
- Let driver autosuspend also after leaving s3c64xx_spi_setup
- Enable runtime PM earlier in s3c64xx_spi_probe and prevent suspending in the relevant part of probe

 drivers/spi/spi-s3c64xx.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

drivers/spi/spi-s3c64xx.c +5 -2

index 8a6ab88..edeac06 100644
@@ -32,6 +32,7 @@
 #define MAX_SPI_PORTS		6
 #define S3C64XX_SPI_QUIRK_POLL		(1 << 0)
 #define S3C64XX_SPI_QUIRK_CS_AUTO	(1 << 1)
+#define AUTOSUSPEND_TIMEOUT	2000
 
 /* Registers and bit-fields */
 

@@ -859,13 +860,15 @@ static int s3c64xx_spi_setup(struct spi_device *spi)
 		}
 	}
 
-	pm_runtime_put(&sdd->pdev->dev);
+	pm_runtime_mark_last_busy(&sdd->pdev->dev);
+	pm_runtime_put_autosuspend(&sdd->pdev->dev);
 	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
 	return 0;
 
 setup_exit:
-	pm_runtime_put(&sdd->pdev->dev);
+	pm_runtime_mark_last_busy(&sdd->pdev->dev);
+	pm_runtime_put_autosuspend(&sdd->pdev->dev);
 	/* setup() returns with device de-selected */
 	if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
 		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);

drivers/spi/spi-s3c64xx.c +8 -9

+	pm_runtime_get_noresume(&pdev->dev);
+
 	/* Setup clocks */
 	sdd->clk = devm_clk_get(&pdev->dev, "spi");
 	if (IS_ERR(sdd->clk)) {
 		dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
 		ret = PTR_ERR(sdd->clk);
-		goto err0;
+		goto err1;
 	}
 
 	if (clk_prepare_enable(sdd->clk)) {
 		dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
 		ret = -EBUSY;
-		goto err0;
+		goto err1;
 	}
 
 	sprintf(clk_name, "spi_busclk%d", sci->src_clk_nr);

@@ -1180,13 +1189,10 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
 	       sdd->regs + S3C64XX_SPI_INT_EN);
 
-	pm_runtime_set_active(&pdev->dev);
-	pm_runtime_enable(&pdev->dev);
-
 	ret = devm_spi_register_master(&pdev->dev, master);
 	if (ret != 0) {
 		dev_err(&pdev->dev, "cannot register SPI master: %d\n", ret);
-		goto err4;
+		goto err3;
 	}
 
 	dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Slaves attached\n",

@@ -1195,15 +1201,19 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 					mem_res, (FIFO_LVL_MASK(sdd) >> 1) + 1,
 					sdd->rx_dma.dmach, sdd->tx_dma.dmach);
 
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
 	return 0;
 
-err4:
-	pm_runtime_disable(&pdev->dev);
-	pm_runtime_set_suspended(&pdev->dev);
 err3: