zephyr/drivers/i2c/i2c_emul.c

162 lines
4.5 KiB
C

/*
* This driver creates fake I2C buses which can contain emulated devices,
* implemented by a separate emulation driver. The API between this driver and
* its emulators is defined by struct i2c_emul_driver_api.
*
* Copyright 2020 Google LLC
* Copyright (c) 2020 Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT zephyr_i2c_emul_controller
#define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(i2c_emul_ctlr);
#include <zephyr/device.h>
#include <zephyr/drivers/emul.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/i2c_emul.h>
#include "i2c-priv.h"
/** Working data for the device */
struct i2c_emul_data {
/* List of struct i2c_emul associated with the device */
sys_slist_t emuls;
/* I2C host configuration */
uint32_t config;
uint32_t bitrate;
};
/**
* Find an emulator by its I2C address
*
* @param dev I2C emulation controller device
* @param addr I2C address of that device
* @return emulator ro use
* @return NULL if not found
*/
static struct i2c_emul *i2c_emul_find(const struct device *dev, int addr)
{
struct i2c_emul_data *data = dev->data;
sys_snode_t *node;
SYS_SLIST_FOR_EACH_NODE(&data->emuls, node) {
struct i2c_emul *emul = NULL;
emul = CONTAINER_OF(node, struct i2c_emul, node);
if (emul->addr == addr) {
return emul;
}
}
return NULL;
}
static int i2c_emul_configure(const struct device *dev, uint32_t dev_config)
{
struct i2c_emul_data *data = dev->data;
data->config = dev_config;
return 0;
}
static int i2c_emul_get_config(const struct device *dev, uint32_t *dev_config)
{
struct i2c_emul_data *data = dev->data;
*dev_config = data->config;
return 0;
}
static int i2c_emul_transfer(const struct device *dev, struct i2c_msg *msgs, uint8_t num_msgs,
uint16_t addr)
{
struct i2c_emul *emul;
const struct i2c_emul_api *api;
int ret;
emul = i2c_emul_find(dev, addr);
if (!emul) {
return -EIO;
}
api = emul->api;
__ASSERT_NO_MSG(emul->api);
__ASSERT_NO_MSG(emul->api->transfer);
if (emul->mock_api != NULL && emul->mock_api->transfer != NULL) {
ret = emul->mock_api->transfer(emul->target, msgs, num_msgs, addr);
if (ret != -ENOSYS) {
return ret;
}
}
return api->transfer(emul->target, msgs, num_msgs, addr);
}
/**
* Set up a new emulator and add it to the list
*
* @param dev I2C emulation controller device
*/
static int i2c_emul_init(const struct device *dev)
{
struct i2c_emul_data *data = dev->data;
int rc;
sys_slist_init(&data->emuls);
rc = emul_init_for_bus(dev);
/* Set config to an uninitialized state */
data->config = (I2C_MODE_CONTROLLER | i2c_map_dt_bitrate(data->bitrate));
return rc;
}
int i2c_emul_register(const struct device *dev, struct i2c_emul *emul)
{
struct i2c_emul_data *data = dev->data;
const char *name = emul->target->dev->name;
sys_slist_append(&data->emuls, &emul->node);
LOG_INF("Register emulator '%s' at I2C addr %02x", name, emul->addr);
return 0;
}
/* Device instantiation */
static const struct i2c_driver_api i2c_emul_api = {
.configure = i2c_emul_configure,
.get_config = i2c_emul_get_config,
.transfer = i2c_emul_transfer,
};
#define EMUL_LINK_AND_COMMA(node_id) \
{ \
.dev = DEVICE_DT_GET(node_id), \
},
#define I2C_EMUL_INIT(n) \
static const struct emul_link_for_bus emuls_##n[] = { \
DT_FOREACH_CHILD_STATUS_OKAY(DT_DRV_INST(n), EMUL_LINK_AND_COMMA)}; \
static struct emul_list_for_bus i2c_emul_cfg_##n = { \
.children = emuls_##n, \
.num_children = ARRAY_SIZE(emuls_##n), \
}; \
static struct i2c_emul_data i2c_emul_data_##n = { \
.bitrate = DT_INST_PROP(n, clock_frequency), \
}; \
I2C_DEVICE_DT_INST_DEFINE(n, i2c_emul_init, NULL, &i2c_emul_data_##n, &i2c_emul_cfg_##n, \
POST_KERNEL, CONFIG_I2C_INIT_PRIORITY, &i2c_emul_api);
DT_INST_FOREACH_STATUS_OKAY(I2C_EMUL_INIT)