[PATCH v3 03/16] mfd: mfd-core: match device tree node against reg property

[Michael Walle <michael@walle.cc>]

There might be multiple children with the device tree compatible, for
example if a MFD has multiple instances of the same function. In this
case only the first is matched and the other children get a wrong
of_node reference.
Add a new option to match also against the unit address of the child
node. Additonally, a new helper OF_MFD_CELL_REG is added.

Signed-off-by: Michael Walle <michael@walle.cc>
---
 drivers/mfd/mfd-core.c   | 29 ++++++++++++++++++++---------
 include/linux/mfd/core.h | 26 ++++++++++++++++++++------
 2 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index e735565969b3..4ecb376338f7 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -117,6 +117,7 @@ static int mfd_add_device(struct device *parent, int id,
 	struct device_node *np = NULL;
 	int ret = -ENOMEM;
 	int platform_id;
+	u32 of_reg;
 	int r;
 
 	if (id == PLATFORM_DEVID_AUTO)
@@ -151,16 +152,26 @@ static int mfd_add_device(struct device *parent, int id,
 
 	if (parent->of_node && cell->of_compatible) {
 		for_each_child_of_node(parent->of_node, np) {
-			if (of_device_is_compatible(np, cell->of_compatible)) {
-				if (!of_device_is_available(np)) {
-					/* Ignore disabled devices error free */
-					ret = 0;
-					goto fail_alias;
-				}
-				pdev->dev.of_node = np;
-				pdev->dev.fwnode = &np->fwnode;
-				break;
+			if (!of_device_is_compatible(np, cell->of_compatible))
+				continue;
+
+			/* also match the unit address if set */
+			if (cell->of_reg & MFD_OF_REG_VALID) {
+				if (of_property_read_u32(np, "reg", &of_reg))
+					continue;
+				if ((cell->of_reg & MFD_OF_REG_MASK) != of_reg)
+					continue;
 			}
+
+			if (!of_device_is_available(np)) {
+				/* Ignore disabled devices error free */
+				ret = 0;
+				goto fail_alias;
+			}
+
+			pdev->dev.of_node = np;
+			pdev->dev.fwnode = &np->fwnode;
+			break;
 		}
 	}
 
diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
index d01d1299e49d..c2c0ad6b14f3 100644
--- a/include/linux/mfd/core.h
+++ b/include/linux/mfd/core.h
@@ -13,8 +13,11 @@
 #include <linux/platform_device.h>
 
 #define MFD_RES_SIZE(arr) (sizeof(arr) / sizeof(struct resource))
+#define MFD_OF_REG_VALID	BIT(31)
+#define MFD_OF_REG_MASK		GENMASK(30, 0)
 
-#define MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, _match)\
+#define MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat,	\
+		     _of_reg, _match)					\
 	{								\
 		.name = (_name),					\
 		.resources = (_res),					\
@@ -22,24 +25,32 @@
 		.platform_data = (_pdata),				\
 		.pdata_size = (_pdsize),				\
 		.of_compatible = (_compat),				\
+		.of_reg = (_of_reg),					\
 		.acpi_match = (_match),					\
 		.id = (_id),						\
 	}
 
+#define OF_MFD_CELL_REG(_name, _res, _pdata, _pdsize, _id, _compat,	\
+			_of_reg)					\
+	MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat,	\
+		     ((_of_reg) | MFD_OF_REG_VALID), NULL)		\
+
 #define OF_MFD_CELL(_name, _res, _pdata, _pdsize,_id, _compat)		\
-	MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, NULL)	\
+	MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat,	\
+		     0, NULL)						\
 
 #define ACPI_MFD_CELL(_name, _res, _pdata, _pdsize, _id, _match)	\
-	MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, _match)	\
+	MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, 0,	\
+		     _match)						\
 
 #define MFD_CELL_BASIC(_name, _res, _pdata, _pdsize, _id)		\
-	MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, NULL)	\
+	MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, 0, NULL) \
 
 #define MFD_CELL_RES(_name, _res)					\
-	MFD_CELL_ALL(_name, _res, NULL, 0, 0, NULL, NULL)		\
+	MFD_CELL_ALL(_name, _res, NULL, 0, 0, NULL, 0, NULL)		\
 
 #define MFD_CELL_NAME(_name)						\
-	MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, NULL)		\
+	MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, 0, NULL)		\
 
 struct irq_domain;
 struct property_entry;
@@ -78,6 +89,9 @@ struct mfd_cell {
 	 */
 	const char		*of_compatible;
 
+	/* matching the reg property if set */
+	unsigned int		of_reg;
+
 	/* Matches ACPI */
 	const struct mfd_cell_acpi_match	*acpi_match;
 
-- 
2.20.1