[PATCH 2/5] mfd: arizona: Fix and factor out read of device tree GPIOs

[Charles Keepax <ckeepax@opensource.wolfsonmicro.com>]

On non-DT systems with device tree built in the current device tree GPIO
reads will overwrite the pdata with zero when they fail. This patch
factors out the reading of GPIOs for the Arizona devices into a helper
function, and ensures that the pdata version will be preserved if the
device tree read fails.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 drivers/mfd/arizona-core.c       |   33 ++++++++++++++++++++++++---------
 include/linux/mfd/arizona/core.h |    3 +++
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
index a45aab9..333621e 100644
--- a/drivers/mfd/arizona-core.c
+++ b/drivers/mfd/arizona-core.c
@@ -512,19 +512,34 @@ int arizona_of_get_type(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(arizona_of_get_type);
 
+int arizona_of_get_named_gpio(struct arizona *arizona, const char *prop,
+			      bool mandatory, int *gpio)
+{
+	int ret;
+
+	ret = of_get_named_gpio(arizona->dev->of_node, prop, 0);
+	if (ret >= 0) {
+		*gpio = ret;
+		return ret;
+	}
+
+	/* Warn if GPIO is mandatory and not specified */
+	if (mandatory && *gpio <= 0)
+		dev_err(arizona->dev,
+				"Mandatory DT gpio %s missing/malformed: %d\n",
+				prop, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(arizona_of_get_named_gpio);
+
 static int arizona_of_get_core_pdata(struct arizona *arizona)
 {
+	struct arizona_pdata *pdata = &arizona->pdata;
 	int ret, i;
 
-	arizona->pdata.reset = of_get_named_gpio(arizona->dev->of_node,
-						 "wlf,reset", 0);
-	if (arizona->pdata.reset < 0)
-		arizona->pdata.reset = 0;
-
-	arizona->pdata.ldoena = of_get_named_gpio(arizona->dev->of_node,
-						  "wlf,ldoena", 0);
-	if (arizona->pdata.ldoena < 0)
-		arizona->pdata.ldoena = 0;
+	arizona_of_get_named_gpio(arizona, "wlf,reset", true, &pdata->reset);
+	arizona_of_get_named_gpio(arizona, "wlf,ldoena", true, &pdata->ldoena);
 
 	ret = of_property_read_u32_array(arizona->dev->of_node,
 					 "wlf,gpio-defaults",
diff --git a/include/linux/mfd/arizona/core.h b/include/linux/mfd/arizona/core.h
index 5cf8b91..16150cc 100644
--- a/include/linux/mfd/arizona/core.h
+++ b/include/linux/mfd/arizona/core.h
@@ -124,4 +124,7 @@ int wm5102_patch(struct arizona *arizona);
 int wm5110_patch(struct arizona *arizona);
 int wm8997_patch(struct arizona *arizona);
 
+extern int arizona_of_get_named_gpio(struct arizona *arizona, const char *prop,
+				     bool mandatory, int *gpio);
+
 #endif
-- 
1.7.2.5