spi/pl022: add IDLE state pin management

This commit allow to put pins in IDLE state in
runtime_suspend and in SLEEP state in suspend, corresponding
to defined semantics in <linux/pinctrl/pinctrl-state.h>.

To do this, just add a boolean parameter runtime
to pl022_resume_resources/pl022_suspend_resources which
indicates if it's called from PM_RUNTIME callbacks or not.

Signed-off-by: Patrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/spi/spi-pl022.c

@@ -371,6 +371,7 @@ struct pl022 {
 	/* Two optional pin states - default & sleep */
 	struct pinctrl			*pinctrl;
 	struct pinctrl_state		*pins_default;
+	struct pinctrl_state		*pins_idle;
 	struct pinctrl_state		*pins_sleep;
 	struct spi_master		*master;
 	struct pl022_ssp_controller	*master_info;
@@ -2116,6 +2117,11 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id)
 	} else
 		dev_err(dev, "could not get default pinstate\n");
 
+	pl022->pins_idle = pinctrl_lookup_state(pl022->pinctrl,
+					      PINCTRL_STATE_IDLE);
+	if (IS_ERR(pl022->pins_idle))
+		dev_dbg(dev, "could not get idle pinstate\n");
+
 	pl022->pins_sleep = pinctrl_lookup_state(pl022->pinctrl,
 					       PINCTRL_STATE_SLEEP);
 	if (IS_ERR(pl022->pins_sleep))
@@ -2305,35 +2311,47 @@ pl022_remove(struct amba_device *adev)
  * the runtime counterparts to handle external resources like
  * clocks, pins and regulators when going to sleep.
  */
-static void pl022_suspend_resources(struct pl022 *pl022)
+static void pl022_suspend_resources(struct pl022 *pl022, bool runtime)
 {
 	int ret;
+	struct pinctrl_state *pins_state;
 
 	clk_disable(pl022->clk);
 
+	pins_state = runtime ? pl022->pins_idle : pl022->pins_sleep;
 	/* Optionally let pins go into sleep states */
-	if (!IS_ERR(pl022->pins_sleep)) {
-		ret = pinctrl_select_state(pl022->pinctrl,
-					   pl022->pins_sleep);
+	if (!IS_ERR(pins_state)) {
+		ret = pinctrl_select_state(pl022->pinctrl, pins_state);
 		if (ret)
-			dev_err(&pl022->adev->dev,
-				"could not set pins to sleep state\n");
+			dev_err(&pl022->adev->dev, "could not set %s pins\n",
+				runtime ? "idle" : "sleep");
 	}
 }
 
-static void pl022_resume_resources(struct pl022 *pl022)
+static void pl022_resume_resources(struct pl022 *pl022, bool runtime)
 {
 	int ret;
 
 	/* Optionaly enable pins to be muxed in and configured */
+	/* First go to the default state */
 	if (!IS_ERR(pl022->pins_default)) {
-		ret = pinctrl_select_state(pl022->pinctrl,
-					   pl022->pins_default);
+		ret = pinctrl_select_state(pl022->pinctrl, pl022->pins_default);
 		if (ret)
 			dev_err(&pl022->adev->dev,
 				"could not set default pins\n");
 	}
 
+	if (!runtime) {
+		/* Then let's idle the pins until the next transfer happens */
+		if (!IS_ERR(pl022->pins_idle)) {
+			ret = pinctrl_select_state(pl022->pinctrl,
+					pl022->pins_idle);
+		if (ret)
+			dev_err(&pl022->adev->dev,
+				"could not set idle pins\n");
+		}
+	}
+
 	clk_enable(pl022->clk);
 }
 #endif
@@ -2351,7 +2369,7 @@ static int pl022_suspend(struct device *dev)
 	}
 
 	pm_runtime_get_sync(dev);
-	pl022_suspend_resources(pl022);
+	pl022_suspend_resources(pl022, false);
 
 	dev_dbg(dev, "suspended\n");
 	return 0;
@@ -2362,7 +2380,7 @@ static int pl022_resume(struct device *dev)
 	struct pl022 *pl022 = dev_get_drvdata(dev);
 	int ret;
 
-	pl022_resume_resources(pl022);
+	pl022_resume_resources(pl022, false);
 	pm_runtime_put(dev);
 
 	/* Start the queue running */
@@ -2381,15 +2399,15 @@ static int pl022_runtime_suspend(struct device *dev)
 {
 	struct pl022 *pl022 = dev_get_drvdata(dev);
 
-	pl022_suspend_resources(pl022);
+	pl022_suspend_resources(pl022, true);
 	return 0;
 }
 
 static int pl022_runtime_resume(struct device *dev)
 {
 	struct pl022 *pl022 = dev_get_drvdata(dev);
 
-	pl022_resume_resources(pl022);
+	pl022_resume_resources(pl022, true);
 	return 0;
 }
 #endif