[U-Boot] [PATCH v1 2/6] syscon: dm: Add a new method to get a regmap from DTS

[Jean-Jacques Hiblot]

syscon_regmap_lookup_by_phandle() can be used to the regmap of a syscon
device from a reference in the DTS. It operates similarly to the linux
version of the namesake function.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
---

 drivers/core/syscon-uclass.c | 23 +++++++++++++++++++++++
 include/syscon.h             | 13 +++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/core/syscon-uclass.c b/drivers/core/syscon-uclass.c
index a69937e..0c76bfc 100644
--- a/drivers/core/syscon-uclass.c
+++ b/drivers/core/syscon-uclass.c
@@ -45,6 +45,29 @@ static int syscon_pre_probe(struct udevice *dev)
 #endif
 }
 
+struct regmap *syscon_regmap_lookup_by_phandle(struct udevice *dev,
+					       const char *name)
+{
+	struct udevice *syscon;
+	struct regmap *r;
+	int err;
+
+	err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
+					   name, &syscon);
+	if (err) {
+		printf("unable to find syscon device\n");
+		return ERR_PTR(err);
+	}
+
+	r = syscon_get_regmap(syscon);
+	if (!r) {
+		printf("unable to find regmap\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	return r;
+}
+
 int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp)
 {
 	struct udevice *dev;
diff --git a/include/syscon.h b/include/syscon.h
index 5d52b1c..23d257a 100644
--- a/include/syscon.h
+++ b/include/syscon.h
@@ -74,6 +74,19 @@ int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp);
 struct regmap *syscon_get_regmap_by_driver_data(ulong driver_data);
 
 /**
+ * syscon_regmap_lookup_by_phandle() - Look up a controller by a phandle
+ *
+ * This operates by looking up the given name in the device (device
+ * tree property) of the device using the system controller.
+ *
+ * @dev:	Device using the system controller
+ * @name:	Name of property referring to the system controller
+ * @return	A pointer to the regmap if found, ERR_PTR(-ve) on error
+ */
+struct regmap *syscon_regmap_lookup_by_phandle(struct udevice *dev,
+					       const char *name);
+
+/**
  * syscon_get_first_range() - get the first memory range from a syscon regmap
  *
  * @driver_data:	Driver data value to look up
-- 
1.9.1