From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Thu, 23 Oct 2025 06:55:59 +0000 (+0200)
Subject: mfd: da9063: Occupy second I2C address
X-Git-Tag: v6.19-rc1~142^2~33
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=18597dbccfa5a99ccb7278046234c0ae29ec7a19;p=thirdparty%2Fkernel%2Flinux.git

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 1ec9ab56442df..a803b7440f09b 100644
--- 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);
 }