mctp_i2c_gpio_controller.h File Reference

#include <stdint.h>
#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/sys/mpsc_lockfree.h>
#include <zephyr/rtio/rtio.h>
#include <zephyr/pmci/mctp/mctp_i2c_gpio_common.h>
#include <libmctp.h>
#include <stdatomic.h>

Go to the source code of this file.

Data Structures
struct	mctp_binding_i2c_gpio_controller
	INTERNAL_HIDDEN. More...

Macros
#define	MCTP_I2C_GPIO_CONTROLLER_DT_DEFINE(_name, _node_id)
	INTERNAL_HIDDEN.

Macro Definition Documentation

MCTP_I2C_GPIO_CONTROLLER_DT_DEFINE

#define MCTP_I2C_GPIO_CONTROLLER_DT_DEFINE	(		_name,
			_node_id )

Value:

        RTIO_DEFINE(_name##_rtio_tx, 5, 5);                                                        \
        RTIO_DEFINE(_name##_rtio_rx, 5, 5);                                                        \
        MCTP_I2C_GPIO_CONTROLLER_DEFINE_IODEVS(_node_id, _name);                                   \
        MCTP_I2C_GPIO_CONTROLLER_DEFINE_GPIOS(_node_id, _name);                                    \
        MCTP_I2C_GPIO_CONTROLLER_DEFINE_IDS(_node_id, _name);                                      \
        MCTP_I2C_GPIO_CONTROLLER_DEFINE_GPIO_CBS(_node_id, _name);                                 \
        K_SEM_DEFINE(_name##_tx_lock, 1, 1);                                                       \
        struct mctp_binding_i2c_gpio_controller _name = {                                          \
                .binding = {                                                                       \
                        .name = STRINGIFY(_name), .version = 1,                                    \
                        .start = mctp_i2c_gpio_controller_start,                                   \
                        .tx = mctp_i2c_gpio_controller_tx,                                         \
                        .pkt_size = MCTP_I2C_GPIO_MAX_PKT_SIZE,                                    \
                },                                                                                 \
                .i2c = DEVICE_DT_GET(DT_PHANDLE(_node_id, i2c)),                                   \
                .num_endpoints = DT_PROP_LEN(_node_id, endpoint_ids),                              \
                .endpoint_ids = _name##_endpoint_ids,                                              \
                .endpoint_gpios = _name##_endpoint_gpios,                                          \
                .endpoint_gpio_cbs = _name##_endpoint_gpio_cbs,                                    \
                .endpoint_iodevs = _name##_endpoint_iodevs,                                        \
                .r_tx = &_name##_rtio_tx,                                                          \
                .r_rx = &_name##_rtio_rx,                                                          \
                .tx_lock = &_name##_tx_lock,                                                       \
        };

INTERNAL_HIDDEN.

Define a MCTP bus binding for I2C controller with GPIO

Rather than mode switching as the MCTP standard wishes, this is a custom binding. On the controller side each neighbor has an associated i2c address and gpio it will listen for a trigger on. When triggered the controller will read the target device. The target device will be expected to have what amounts to two registers, one containing a message length and another containing a FIFO like register producing the message bytes.

Thus the sequence for a I2C target to send a message would be...

1. Setup a length and message value (pseudo registers).
2. Signal the controller with a GPIO level set
3. The controller then is expected to read the length (write of addr 0 + read 1 byte)
4. The controller then is expected to read the message (write of addr 1 + read N bytes)
5. The target clears the pin set
6. The controller reports a message receive to MCTP

Parameters

_name	Symbolic name of the bus binding variable
_node_id	DeviceTree Node containing the configuration of this MCTP binding