[PATCH v6 4/7] mfd: nct6694: Rename driver to nct6694-usb and update Kconfig

[a0282524688@gmail.com]

From: Ming Yu <a0282524688@gmail.com>

Rename nct6694.c to nct6694-usb.c to accurately reflect that it
implements the USB transport backend.

Additionally, introduce a new MFD_NCT6694_USB Kconfig option and convert
the existing MFD_NCT6694 into a hidden core symbol. The core symbol is
now automatically selected by the transport drivers.

This Kconfig and naming restructure aligns with standard MFD transport
abstraction practices, paving the way for future interfaces (e.g., HIF)
to be seamlessly integrated.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
Changes in v6:

Changes in v5:
- Split from the monolithic v4 patch to follow the single logical change
  principle.

 MAINTAINERS                              |  2 +-
 drivers/mfd/Kconfig                      | 31 ++++++++++++++++--------
 drivers/mfd/Makefile                     |  2 +-
 drivers/mfd/{nct6694.c => nct6694-usb.c} |  0
 4 files changed, 23 insertions(+), 12 deletions(-)
 rename drivers/mfd/{nct6694.c => nct6694-usb.c} (100%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 15011f5752a9..3f483c2d783d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19318,7 +19318,7 @@ S:	Supported
 F:	drivers/gpio/gpio-nct6694.c
 F:	drivers/hwmon/nct6694-hwmon.c
 F:	drivers/i2c/busses/i2c-nct6694.c
-F:	drivers/mfd/nct6694.c
+F:	drivers/mfd/nct6694-usb.c
 F:	drivers/net/can/usb/nct6694_canfd.c
 F:	drivers/rtc/rtc-nct6694.c
 F:	drivers/watchdog/nct6694_wdt.c
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 763ce6a34782..5506a0adf3ec 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1164,19 +1164,30 @@ config MFD_MENF21BMC
 	  will be called menf21bmc.
 
 config MFD_NCT6694
-	tristate "Nuvoton NCT6694 support"
+	tristate
 	select MFD_CORE
+	help
+	  Core MFD support for the Nuvoton NCT6694 peripheral expander.
+	  This provides the common APIs and shared structures used by all
+	  interfaces (USB, HIF) to access the NCT6694 hardware features
+	  such as GPIO, I2C, CAN-FD, Watchdog, ADC, PWM, and RTC.
+
+	  It is selected automatically by the transport interface drivers.
+
+config MFD_NCT6694_USB
+	tristate "Nuvoton NCT6694 USB interface support"
+	select MFD_NCT6694
 	depends on USB
 	help
-	  This enables support for the Nuvoton USB device NCT6694, which shares
-	  peripherals.
-	  The Nuvoton NCT6694 is a peripheral expander with 16 GPIO chips,
-	  6 I2C controllers, 2 CANfd controllers, 2 Watchdog timers, ADC,
-	  PWM, and RTC.
-	  This driver provides core APIs to access the NCT6694 hardware
-	  monitoring and control features.
-	  Additional drivers must be enabled to utilize the specific
-	  functionalities of the device.
+	  This enables support for the Nuvoton NCT6694 peripheral expander
+	  connected via the USB interface.
+
+	  The transport driver uses USB bulk and interrupt transfers to
+	  communicate with the NCT6694 firmware. Enable this option if you
+	  are using the NCT6694 via a USB connection.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called nct6694-usb.
 
 config MFD_OCELOT
 	tristate "Microsemi Ocelot External Control Support"
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index dd4bb7e77c33..48caac64f3d8 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -124,7 +124,7 @@ obj-$(CONFIG_MFD_MC13XXX_I2C)	+= mc13xxx-i2c.o
 
 obj-$(CONFIG_MFD_PF1550)	+= pf1550.o
 
-obj-$(CONFIG_MFD_NCT6694)	+= nct6694.o
+obj-$(CONFIG_MFD_NCT6694_USB)	+= nct6694-usb.o
 
 obj-$(CONFIG_MFD_CORE)		+= mfd-core.o
 
diff --git a/drivers/mfd/nct6694.c b/drivers/mfd/nct6694-usb.c
similarity index 100%
rename from drivers/mfd/nct6694.c
rename to drivers/mfd/nct6694-usb.c
-- 
2.34.1