mfd: da9063: Occupy second I2C address

The second address can be used as a shortcut to access register pages
2+3. The driver does not use this feature yet. The second address should
still be marked as used, otherwise userspace could interfere with the
driver.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Link: https://patch.msgid.link/20251023065610.2855-2-wsa+renesas@sang-engineering.com
Signed-off-by: Lee Jones <lee@kernel.org>

diff --git a/drivers/mfd/da9063-i2c.c b/drivers/mfd/da9063-i2c.c
index 1ec9ab56442dfc0322fe0dc96a28f93660013362..a803b7440f09bc87ce46c51d9f780c1789597504 100644 (file)
--- a/drivers/mfd/da9063-i2c.c
+++ b/drivers/mfd/da9063-i2c.c
@@ -469,6 +469,9 @@ static int da9063_i2c_probe(struct i2c_client *i2c)
                }
        }
 
+       /* Reserve our unused second address so userspace won't interfere */
+       devm_i2c_new_dummy_device(&i2c->dev, i2c->adapter, i2c->addr + 1);
+
        return da9063_device_init(da9063, i2c->irq);
 }