1 /*
2 * This driver creates fake I2C buses which can contain emulated devices,
3 * implemented by a separate emulation driver. The API between this driver and
4 * its emulators is defined by struct i2c_emul_driver_api.
5 *
6 * Copyright 2020 Google LLC
7 * Copyright (c) 2020 Nordic Semiconductor ASA
8 *
9 * SPDX-License-Identifier: Apache-2.0
10 */
11
12 #define DT_DRV_COMPAT zephyr_i2c_emul_controller
13
14 #define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
15 #include <zephyr/logging/log.h>
16 LOG_MODULE_REGISTER(i2c_emul_ctlr);
17
18 #include <zephyr/device.h>
19 #include <zephyr/drivers/emul.h>
20 #include <zephyr/drivers/i2c.h>
21 #include <zephyr/drivers/i2c_emul.h>
22
23 #include "i2c-priv.h"
24
25 /** Working data for the device */
26 struct i2c_emul_data {
27 /* List of struct i2c_emul associated with the device */
28 sys_slist_t emuls;
29 /* I2C host configuration */
30 uint32_t config;
31 uint32_t bitrate;
32 };
33
34 /**
35 * Find an emulator by its I2C address
36 *
37 * @param dev I2C emulation controller device
38 * @param addr I2C address of that device
39 * @return emulator ro use
40 * @return NULL if not found
41 */
i2c_emul_find(const struct device * dev,int addr)42 static struct i2c_emul *i2c_emul_find(const struct device *dev, int addr)
43 {
44 struct i2c_emul_data *data = dev->data;
45 sys_snode_t *node;
46
47 SYS_SLIST_FOR_EACH_NODE(&data->emuls, node) {
48 struct i2c_emul *emul = NULL;
49
50 emul = CONTAINER_OF(node, struct i2c_emul, node);
51 if (emul->addr == addr) {
52 return emul;
53 }
54 }
55
56 return NULL;
57 }
58
i2c_emul_configure(const struct device * dev,uint32_t dev_config)59 static int i2c_emul_configure(const struct device *dev, uint32_t dev_config)
60 {
61 struct i2c_emul_data *data = dev->data;
62
63 data->config = dev_config;
64
65 return 0;
66 }
67
i2c_emul_get_config(const struct device * dev,uint32_t * dev_config)68 static int i2c_emul_get_config(const struct device *dev, uint32_t *dev_config)
69 {
70 struct i2c_emul_data *data = dev->data;
71
72 *dev_config = data->config;
73
74 return 0;
75 }
76
i2c_emul_transfer(const struct device * dev,struct i2c_msg * msgs,uint8_t num_msgs,uint16_t addr)77 static int i2c_emul_transfer(const struct device *dev, struct i2c_msg *msgs, uint8_t num_msgs,
78 uint16_t addr)
79 {
80 struct i2c_emul *emul;
81 const struct i2c_emul_api *api;
82 int ret;
83
84 emul = i2c_emul_find(dev, addr);
85 if (!emul) {
86 return -EIO;
87 }
88
89 api = emul->api;
90 __ASSERT_NO_MSG(emul->api);
91 __ASSERT_NO_MSG(emul->api->transfer);
92
93 ret = api->transfer(emul->target, msgs, num_msgs, addr);
94 if (ret) {
95 return ret;
96 }
97
98 return 0;
99 }
100
101 /**
102 * Set up a new emulator and add it to the list
103 *
104 * @param dev I2C emulation controller device
105 */
i2c_emul_init(const struct device * dev)106 static int i2c_emul_init(const struct device *dev)
107 {
108 struct i2c_emul_data *data = dev->data;
109 int rc;
110
111 sys_slist_init(&data->emuls);
112
113 rc = emul_init_for_bus(dev);
114
115 /* Set config to an uninitialized state */
116 data->config = (I2C_MODE_CONTROLLER | i2c_map_dt_bitrate(data->bitrate));
117
118 return rc;
119 }
120
i2c_emul_register(const struct device * dev,struct i2c_emul * emul)121 int i2c_emul_register(const struct device *dev, struct i2c_emul *emul)
122 {
123 struct i2c_emul_data *data = dev->data;
124 const char *name = emul->target->dev->name;
125
126 sys_slist_append(&data->emuls, &emul->node);
127
128 LOG_INF("Register emulator '%s' at I2C addr %02x\n", name, emul->addr);
129
130 return 0;
131 }
132
133 /* Device instantiation */
134
135 static struct i2c_driver_api i2c_emul_api = {
136 .configure = i2c_emul_configure,
137 .get_config = i2c_emul_get_config,
138 .transfer = i2c_emul_transfer,
139 };
140
141 #define EMUL_LINK_AND_COMMA(node_id) \
142 { \
143 .dev = DEVICE_DT_GET(node_id), \
144 },
145
146 #define I2C_EMUL_INIT(n) \
147 static const struct emul_link_for_bus emuls_##n[] = { \
148 DT_FOREACH_CHILD_STATUS_OKAY(DT_DRV_INST(n), EMUL_LINK_AND_COMMA)}; \
149 static struct emul_list_for_bus i2c_emul_cfg_##n = { \
150 .children = emuls_##n, \
151 .num_children = ARRAY_SIZE(emuls_##n), \
152 }; \
153 static struct i2c_emul_data i2c_emul_data_##n = { \
154 .bitrate = DT_INST_PROP(n, clock_frequency), \
155 }; \
156 I2C_DEVICE_DT_INST_DEFINE(n, i2c_emul_init, NULL, &i2c_emul_data_##n, &i2c_emul_cfg_##n, \
157 POST_KERNEL, CONFIG_I2C_INIT_PRIORITY, &i2c_emul_api);
158
159 DT_INST_FOREACH_STATUS_OKAY(I2C_EMUL_INIT)
160
