i2c: spacemit: add support for SpacemiT K1 SoC

This patch introduces basic I2C support for the SpacemiT K1 SoC,
utilizing interrupts for transfers.

The driver has been tested using i2c-tools on a Bananapi-F3 board,
and basic I2C read/write operations have been confirmed to work.

Signed-off-by: Troy Mitchell <troymitchell988@gmail.com>
Reviewed-by: Alex Elder <elder@riscstar.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250319-k1-i2c-master-v8-2-013e2df2b78d@gmail.com

Author: TroyMitchell911

drivers/i2c/busses/Kconfig

@@ -783,6 +783,23 @@ config I2C_JZ4780
 
 	 If you don't know what to do here, say N.
 
+config I2C_K1
+	tristate "SpacemiT K1 I2C adapter"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	depends on OF
+	help
+	  This option enables support for the I2C interface on the SpacemiT K1
+	  platform.
+
+	  If you enable this configuration, the kernel will include support for
+	  the I2C adapter specific to the SpacemiT K1 platform. This driver can
+	  be used to manage I2C bus transactions, which are necessary for
+	  interfacing with I2C peripherals such as sensors, EEPROMs, and other
+	  devices.
+
+	  This driver can also be built as a module.  If so, the
+	  module will be called `i2c-k1`.
+
 config I2C_KEBA
 	tristate "KEBA I2C controller support"
 	depends on HAS_IOMEM

drivers/i2c/busses/Makefile

@@ -74,6 +74,7 @@ obj-$(CONFIG_I2C_IMX)		+= i2c-imx.o
 obj-$(CONFIG_I2C_IMX_LPI2C)	+= i2c-imx-lpi2c.o
 obj-$(CONFIG_I2C_IOP3XX)	+= i2c-iop3xx.o
 obj-$(CONFIG_I2C_JZ4780)	+= i2c-jz4780.o
+obj-$(CONFIG_I2C_K1)		+= i2c-k1.o
 obj-$(CONFIG_I2C_KEBA)		+= i2c-keba.o
 obj-$(CONFIG_I2C_KEMPLD)	+= i2c-kempld.o
 obj-$(CONFIG_I2C_LPC2K)		+= i2c-lpc2k.o