spi: add power control when set_cs

As to set_cs takes effect immediately, power spi
is needed when setup spi.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Luhua Xu <luhua.xu@mediatek.com>
Link: https://lore.kernel.org/r/1572426234-30019-1-git-send-email-luhua.xu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -3261,7 +3261,20 @@ int spi_setup(struct spi_device *spi)
 	if (spi->controller->setup)
 		status = spi->controller->setup(spi);
 
-	spi_set_cs(spi, false);
+	if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
+		status = pm_runtime_get_sync(spi->controller->dev.parent);
+		if (status < 0) {
+			pm_runtime_put_noidle(spi->controller->dev.parent);
+			dev_err(&spi->controller->dev, "Failed to power device: %d\n",
+				status);
+			return status;
+		}
+		spi_set_cs(spi, false);
+		pm_runtime_mark_last_busy(spi->controller->dev.parent);
+		pm_runtime_put_autosuspend(spi->controller->dev.parent);
+	} else {
+		spi_set_cs(spi, false);
+	}
 
 	if (spi->rt && !spi->controller->rt) {
 		spi->controller->rt = true;