[PATCH v3 2/5] i2c: designware: Create shared header hosting driver name

[Florian Fainelli]

We have a number of drivers that reference the string "i2c_designware"
towards two goals:

- ensure their device gets bound to the i2c_designware platform_driver
- create a clock lookup reference that matches the i2c_designware
  instance number for the i2c-designware-platdrv.c driver to be able to
  lookup the input reference clock

Since this string is copied in a bunch of different places and since it
is possible to get this named wrong (see [1] and [2]) with unintended
consequences, create a header file that hosts that define for other
drivers to use and all agree on the correct name to use.

Link: https://lore.kernel.org/all/20240422084109.3201-1-duanqiangwen@xxxxxxxxxxxxx/ [1]
Link: https://lore.kernel.org/all/20240422084109.3201-2-duanqiangwen@xxxxxxxxxxxxx/ [2]
Signed-off-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
---
 MAINTAINERS                                  |  1 +
 drivers/i2c/busses/i2c-designware-platdrv.c  |  4 +++-
 include/linux/platform_data/i2c-designware.h | 12 ++++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/platform_data/i2c-designware.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 2d5acd6d98c4..da1b39df2b94 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21438,6 +21438,7 @@ R:	Jan Dabros <jsd@xxxxxxxxxxxx>
 L:	linux-i2c@xxxxxxxxxxxxxxx
 S:	Supported
 F:	drivers/i2c/busses/i2c-designware-*
+F:	include/linux/platform_data/i2c-designware.h
 
 SYNOPSYS DESIGNWARE MMC/SD/SDIO DRIVER
 M:	Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0be7b0dc849b..107945d0337e 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -33,6 +33,8 @@
 #include <linux/suspend.h>
 #include <linux/units.h>
 
+#include <linux/platform_data/i2c-designware.h>
+
 #include "i2c-designware-core.h"
 
 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
@@ -489,7 +491,7 @@ static struct platform_driver dw_i2c_driver = {
 	.probe = dw_i2c_plat_probe,
 	.remove_new = dw_i2c_plat_remove,
 	.driver		= {
-		.name	= "i2c_designware",
+		.name	= I2C_DESIGNWARE_NAME,
 		.of_match_table = of_match_ptr(dw_i2c_of_match),
 		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
 		.pm	= pm_ptr(&dw_i2c_dev_pm_ops),
diff --git a/include/linux/platform_data/i2c-designware.h b/include/linux/platform_data/i2c-designware.h
new file mode 100644
index 000000000000..1196103df4f5
--- /dev/null
+++ b/include/linux/platform_data/i2c-designware.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __I2C_DESIGNWARE_PDATA_H__
+#define __I2C_DESIGNWARE_PDATA_H__
+
+/*
+ * This is the i2c-designware-platdrv.c platform driver name. This name is used
+ * to bind the device to the driver as well as by the driver itself to request
+ * the input reference clock.
+ */
+#define I2C_DESIGNWARE_NAME	"i2c_designware"
+
+#endif /* __I2C_DESIGNWARE_PDATA_H__ */
-- 
2.34.1