The NPCX SMB modules provides full support for a two-wire SMBus/I2C
synchronous serial interface. Each SMBus/I2C interface is a two-wire
serial interface that is compatible with both Intel SMBus and Philips
I2C physical layer. There are 8 SMBus modules and 10 buses in NPCX7
series.
In NPCX7 series, the SMB5 and SMB6 modules contain a two-way switch to
support two separate SMBus/I2C buses (ports) with one SMB module
(controller) Please refer Section 4.7.2 in the datasheet. In order to
support it, this CL seperates the i2c driver into port and controller
drivers. The controller driver is in charge of i2c module operations
and internal state machine. The port driver is in charge of pin-mux
and connection between Zehpyr i2c api interface and controller driver.
All of modules have separate 32-byte transmit FIFO and 32-byte receive
FIFO buffers. These FIFO buffers reduce firmware overhead during long
SMBus transactions by allowing the Core to write or read more than one
data byte at a time to/from the SMB module.
The CL also includes:
— Add npcx i2c port/controller device tree declarations.
— Zephyr i2c api implementation.
— Add "i2c-0" aliases in npcx7m6fb.dts for i2c test suites.
Signed-off-by: Mulin Chao <MLChao@nuvoton.com>
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