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 <hkallweit1@gmail.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-s3c64xx.c

@@ -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);
@@ -1162,6 +1165,12 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
 		goto err2;
 	}
 
+	pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
 	/* Setup Deufult Mode */
 	s3c64xx_spi_hwinit(sdd, sdd->port_id);
 
@@ -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",
@@ -1195,12 +1201,16 @@ 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:
+err3:
+	pm_runtime_put_noidle(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
-err3:
+
 	clk_disable_unprepare(sdd->src_clk);
 err2:
 	clk_disable_unprepare(sdd->clk);