[PATCH v2] mfd: do not assign already already assigned compatible of_nodes

From: Valentin Longchamp
Date: Tue Oct 25 2016 - 04:11:35 EST


If 2 similar cells have the same of_compatible (2 instances of the same
functionality), they both are assigned the first found of_node with this
compatible. In the below example, the pdev of both cells get the child@0
of_node.

parent@0 { /* MFD devices with 2 cells
reg = <0>;
child@0 {
reg = <0>;
compatible = "child-driver";
};
child@1 {
reg = <1>;
compatible = "child-driver";
};
};

To avoid this, the found of_nodes are checked to see if they are already
assigned in the children of the parent dev and are only assigned if
still "available" (not assigned to a child).

This allows the 2nd cell's pdev to get the child@1 of_node.

Signed-off-by: Valentin Longchamp <valentin.longchamp@xxxxxxxxxxx>
---
drivers/mfd/mfd-core.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index 3ac486a..a684ce5 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -137,6 +137,19 @@ static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
}
#endif

+static inline int mfd_check_node_callback(struct device *dev, void *data)
+{
+ struct device_node *np = data;
+
+ return dev->of_node == np;
+}
+
+static inline int mfd_is_node_allocated_to_dev(struct device *dev,
+ struct device_node *node)
+{
+ return device_for_each_child(dev, node, mfd_check_node_callback);
+}
+
static int mfd_add_device(struct device *parent, int id,
const struct mfd_cell *cell, atomic_t *usage_count,
struct resource *mem_base,
@@ -178,8 +191,10 @@ 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)) {
- pdev->dev.of_node = np;
- break;
+ if (!mfd_is_node_allocated_to_dev(parent, np)) {
+ pdev->dev.of_node = np;
+ break;
+ }
}
}
}
--
1.8.3.1