zephyr/drivers/i2c/i2c_emul.c

166 lines
3.6 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 <logging/log.h>
LOG_MODULE_REGISTER(i2c_emul_ctlr);
#include <device.h>
#include <drivers/emul.h>
#include <drivers/i2c.h>
#include <drivers/i2c_emul.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;
};
/**
* 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;
if (data->config == -1) {
return -EIO;
}
*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);
ret = api->transfer(emul, msgs, num_msgs, addr);
if (ret) {
return ret;
}
return 0;
}
/**
* 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;
const struct emul_list_for_bus *list = dev->config;
int rc;
sys_slist_init(&data->emuls);
rc = emul_init_for_bus_from_list(dev, list);
/* Set config to an uninitialized state */
data->config = -1;
return rc;
}
int i2c_emul_register(const struct device *dev, const char *name,
struct i2c_emul *emul)
{
struct i2c_emul_data *data = dev->data;
sys_slist_append(&data->emuls, &emul->node);
LOG_INF("Register emulator '%s' at I2C addr %02x\n", name, emul->addr);
return 0;
}
/* Device instantiation */
static 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) { \
.label = DT_LABEL(node_id), \
},
#define I2C_EMUL_INIT(n) \
static const struct emul_link_for_bus emuls_##n[] = { \
DT_FOREACH_CHILD(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; \
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)