mfd: core: Fix platform-device id generation

Make sure to always honour multi-function devices registered with
PLATFORM_DEVID_NONE (-1) or PLATFORM_DEVID_AUTO (-2) as id base. In this
case it does not make sense to append the cell id to the mfd-id base and
potentially change the requested behaviour.

Specifically this will allow multi-function devices to be registered
with PLATFORM_DEVID_AUTO while still having non-zero cell ids.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index f3338fe9d069..2a87f69be53d 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -125,9 +125,15 @@ static int mfd_add_device(struct device *parent, int id,
         struct platform_device *pdev;
         struct device_node *np = NULL;
         int ret = -ENOMEM;
+        int platform_id;
         int r;
 
-        pdev = platform_device_alloc(cell->name, id + cell->id);
+        if (id < 0)
+                platform_id = id;
+        else
+                platform_id = id + cell->id;
+
+        pdev = platform_device_alloc(cell->name, platform_id);
         if (!pdev)
                 goto fail_alloc;