From: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
[ Upstream commit 0445efacec75b85c2a3c176957ee050ba9be53f0 ]
The nvmem cell binding applies to all eeprom child nodes matching
"^.*@[0-9a-f]+$" without taking a compatible into account.
Linux drivers, like at24, are even more extensive and assume
_all_ at24 eeprom child nodes to be nvmem cells since e888d445ac33
("nvmem: resolve cells from DT at registration time").
Since df5f3b6f5357 ("dt-bindings: nvmem: stm32: new property for
data access"), the additionalProperties: True means it's Ok to have
other properties as long as they don't match "^.*@[0-9a-f]+$".
The barebox bootloader extends the MTD partitions binding to
EEPROM and can fix up following device tree node:
&eeprom {
partitions {
compatible = "fixed-partitions";
};
};
This is allowed binding-wise, but drivers using nvmem_register()
like at24 will fail to parse because the function expects all child
nodes to have a reg property present. This results in the whole
EEPROM driver probe failing despite the device tree being correct.
Fix this by skipping nodes lacking a reg property instead of
returning an error. This effectively makes the drivers adhere
to the binding because all nodes with a unit address must have
a reg property and vice versa.
Fixes: e888d445ac33 ("nvmem: resolve cells from DT at registration time").
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210129171430.11328-6-srinivas.kandagatla@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvmem/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 1a3460a8e73ab..9b6ab83956c3b 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -545,7 +545,9 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
for_each_child_of_node(parent, child) {
addr = of_get_property(child, "reg", &len);
- if (!addr || (len < 2 * sizeof(u32))) {
+ if (!addr)
+ continue;
+ if (len < 2 * sizeof(u32)) {
dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
return -EINVAL;
}
--
2.27.0
