pinctrl: implement devm_pinctrl_get()/put()

These functions allow the driver core to automatically clean up any
allocations made by drivers, thus leading to simplified drivers.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 59027ab8347..2eaa1876534 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -23,6 +23,7 @@
 #include <linux/sysfs.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/pinctrl/machine.h>
 #include "core.h"
@@ -801,6 +802,61 @@ int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state)
 }
 EXPORT_SYMBOL_GPL(pinctrl_select_state);
 
+static void devm_pinctrl_release(struct device *dev, void *res)
+{
+	pinctrl_put(*(struct pinctrl **)res);
+}
+
+/**
+ * struct devm_pinctrl_get() - Resource managed pinctrl_get()
+ * @dev: the device to obtain the handle for
+ *
+ * If there is a need to explicitly destroy the returned struct pinctrl,
+ * devm_pinctrl_put() should be used, rather than plain pinctrl_put().
+ */
+struct pinctrl *devm_pinctrl_get(struct device *dev)
+{
+	struct pinctrl **ptr, *p;
+
+	ptr = devres_alloc(devm_pinctrl_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	p = pinctrl_get(dev);
+	if (!IS_ERR(p)) {
+		*ptr = p;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(devm_pinctrl_get);
+
+static int devm_pinctrl_match(struct device *dev, void *res, void *data)
+{
+	struct pinctrl **p = res;
+
+	return *p == data;
+}
+
+/**
+ * devm_pinctrl_put() - Resource managed pinctrl_put()
+ * @p: the pinctrl handle to release
+ *
+ * Deallocate a struct pinctrl obtained via devm_pinctrl_get(). Normally
+ * this function will not need to be called and the resource management
+ * code will ensure that the resource is freed.
+ */
+void devm_pinctrl_put(struct pinctrl *p)
+{
+	WARN_ON(devres_destroy(p->dev, devm_pinctrl_release,
+			       devm_pinctrl_match, p));
+	pinctrl_put(p);
+}
+EXPORT_SYMBOL_GPL(devm_pinctrl_put);
+
 int pinctrl_register_map(struct pinctrl_map const *maps, unsigned num_maps,
 			 bool dup, bool locked)
 {