[PATCH v4 3/8] i2c: core: Add a format macro for I2C device names

[Daniel Scally]

Some places in the kernel allow users to map resources to a device
using device name (for example, in the struct gpiod_lookup_table).
Currently this involves waiting for the I2C client to have been registered
so we can use dev_name(&client->dev). We want to add a function to allow
users to refer to an I2C device by name before it has been instantiated,
so create a macro for the format that's accessible outside the I2C layer
and use it in i2c_dev_set_name().

Acked-by: Wolfram Sang <wsa at kernel.org>
Suggested-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Sakari Ailus <sakari.ailus at linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Signed-off-by: Daniel Scally <djrscally at gmail.com>
---
Changes since v3:
	- None

 drivers/i2c/i2c-core-base.c | 4 ++--
 include/linux/i2c.h         | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 5a97e4a02fa2..2ca50a6f5514 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -852,12 +852,12 @@ static void i2c_dev_set_name(struct i2c_adapter *adap,
 	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 
 	if (info && info->dev_name) {
-		dev_set_name(&client->dev, "i2c-%s", info->dev_name);
+		dev_set_name(&client->dev, I2C_DEV_NAME_FORMAT, info->dev_name);
 		return;
 	}
 
 	if (adev) {
-		dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
+		dev_set_name(&client->dev, I2C_DEV_NAME_FORMAT, acpi_dev_name(adev));
 		return;
 	}
 
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e8f2ac8c9c3d..d9f433617a8d 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -39,6 +39,9 @@ enum i2c_slave_event;
 typedef int (*i2c_slave_cb_t)(struct i2c_client *client,
 			      enum i2c_slave_event event, u8 *val);
 
+/* I2C Device Name Format - to maintain consistency outside the i2c layer */
+#define I2C_DEV_NAME_FORMAT		"i2c-%s"
+
 /* I2C Frequency Modes */
 #define I2C_MAX_STANDARD_MODE_FREQ	100000
 #define I2C_MAX_FAST_MODE_FREQ		400000
-- 
2.25.1