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1 0 : /*
2 : * Copyright (c) 2020 Nordic Semiconductor ASA
3 : * Copyright 2020 Google LLC
4 : *
5 : * SPDX-License-Identifier: Apache-2.0
6 : */
7 :
8 : #ifndef ZEPHYR_INCLUDE_DRIVERS_EMUL_H_
9 : #define ZEPHYR_INCLUDE_DRIVERS_EMUL_H_
10 :
11 : /**
12 : * @brief Emulators used to test drivers and higher-level code that uses them
13 : * @defgroup io_emulators Emulator interface
14 : * @ingroup testing
15 : * @{
16 : */
17 :
18 : #ifdef __cplusplus
19 : extern "C" {
20 : #endif /* __cplusplus */
21 :
22 : struct emul;
23 :
24 : /* #includes required after forward-declaration of struct emul later defined in this header. */
25 : #include <zephyr/device.h>
26 : #include <zephyr/devicetree.h>
27 : #include <zephyr/drivers/espi_emul.h>
28 : #include <zephyr/drivers/i2c_emul.h>
29 : #include <zephyr/drivers/spi_emul.h>
30 : #include <zephyr/drivers/mspi_emul.h>
31 : #include <zephyr/drivers/uart_emul.h>
32 : #include <zephyr/sys/iterable_sections.h>
33 :
34 : /**
35 : * The types of supported buses.
36 : */
37 0 : enum emul_bus_type {
38 : EMUL_BUS_TYPE_I2C,
39 : EMUL_BUS_TYPE_ESPI,
40 : EMUL_BUS_TYPE_SPI,
41 : EMUL_BUS_TYPE_MSPI,
42 : EMUL_BUS_TYPE_UART,
43 : EMUL_BUS_TYPE_NONE,
44 : };
45 :
46 : /**
47 : * Structure uniquely identifying a device to be emulated
48 : */
49 1 : struct emul_link_for_bus {
50 0 : const struct device *dev;
51 : };
52 :
53 : /** List of emulators attached to a bus */
54 1 : struct emul_list_for_bus {
55 : /** Identifiers for children of the node */
56 1 : const struct emul_link_for_bus *children;
57 : /** Number of children of the node */
58 1 : unsigned int num_children;
59 : };
60 :
61 : /**
62 : * Standard callback for emulator initialisation providing the initialiser
63 : * record and the device that calls the emulator functions.
64 : *
65 : * @param emul Emulator to init
66 : * @param parent Parent device that is using the emulator
67 : */
68 1 : typedef int (*emul_init_t)(const struct emul *emul, const struct device *parent);
69 :
70 : /**
71 : * Emulator API stub when an emulator is not actually placed on a bus.
72 : */
73 1 : struct no_bus_emul {
74 0 : void *api;
75 0 : uint16_t addr;
76 : };
77 :
78 : /** An emulator instance - represents the *target* emulated device/peripheral that is
79 : * interacted with through an emulated bus. Instances of emulated bus nodes (e.g. i2c_emul)
80 : * and emulators (i.e. struct emul) are exactly 1..1
81 : */
82 1 : struct emul {
83 : /** function used to initialise the emulator state */
84 1 : emul_init_t init;
85 : /** handle to the device for which this provides low-level emulation */
86 1 : const struct device *dev;
87 : /** Emulator-specific configuration data */
88 1 : const void *cfg;
89 : /** Emulator-specific data */
90 1 : void *data;
91 : /** The bus type that the emulator is attached to */
92 1 : enum emul_bus_type bus_type;
93 : /** Pointer to the emulated bus node */
94 1 : union bus {
95 0 : struct i2c_emul *i2c;
96 0 : struct espi_emul *espi;
97 0 : struct spi_emul *spi;
98 0 : struct mspi_emul *mspi;
99 0 : struct uart_emul *uart;
100 0 : struct no_bus_emul *none;
101 0 : } bus;
102 : /** Address of the API structure exposed by the emulator instance */
103 1 : const void *backend_api;
104 : };
105 :
106 : /**
107 : * @brief Use the devicetree node identifier as a unique name.
108 : *
109 : * @param node_id A devicetree node identifier
110 : */
111 1 : #define EMUL_DT_NAME_GET(node_id) _CONCAT(__emulreg_, node_id)
112 :
113 : /* Get a unique identifier based on the given _dev_node_id's reg property and
114 : * the bus its on. Intended for use in other internal macros when declaring {bus}_emul
115 : * structs in peripheral emulators.
116 : */
117 : #define Z_EMUL_REG_BUS_IDENTIFIER(_dev_node_id) _CONCAT(_CONCAT(__emulreg_, _dev_node_id), _bus)
118 :
119 : /* Conditionally places text based on what bus _dev_node_id is on. */
120 : #define Z_EMUL_BUS(_dev_node_id, _i2c, _espi, _spi, _mspi, _uart, _none) \
121 : COND_CODE_1(DT_ON_BUS(_dev_node_id, i2c), (_i2c), \
122 : (COND_CODE_1(DT_ON_BUS(_dev_node_id, espi), (_espi), \
123 : (COND_CODE_1(DT_ON_BUS(_dev_node_id, spi), (_spi), \
124 : (COND_CODE_1(DT_ON_BUS(_dev_node_id, mspi), (_mspi), \
125 : (COND_CODE_1(DT_ON_BUS(_dev_node_id, uart), (_uart), \
126 : (_none))))))))))
127 :
128 : /**
129 : * @brief Define a new emulator
130 : *
131 : * This adds a new struct emul to the linker list of emulations. This is
132 : * typically used in your emulator's DT_INST_FOREACH_STATUS_OKAY() clause.
133 : *
134 : * @param node_id Node ID of the driver to emulate (e.g. DT_DRV_INST(n)); the node_id *MUST* have a
135 : * corresponding DEVICE_DT_DEFINE().
136 : * @param init_fn function to call to initialise the emulator (see emul_init typedef)
137 : * @param data_ptr emulator-specific data
138 : * @param cfg_ptr emulator-specific configuration data
139 : * @param bus_api emulator-specific bus api
140 : * @param _backend_api emulator-specific backend api
141 : */
142 1 : #define EMUL_DT_DEFINE(node_id, init_fn, data_ptr, cfg_ptr, bus_api, _backend_api) \
143 : static struct Z_EMUL_BUS(node_id, i2c_emul, espi_emul, spi_emul, mspi_emul, uart_emul, \
144 : no_bus_emul) Z_EMUL_REG_BUS_IDENTIFIER(node_id) = { \
145 : .api = bus_api, \
146 : IF_ENABLED(DT_NODE_HAS_PROP(node_id, reg), \
147 : (.Z_EMUL_BUS(node_id, addr, chipsel, chipsel, dev_idx, dummy, addr) = \
148 : DT_REG_ADDR(node_id),))}; \
149 : const STRUCT_SECTION_ITERABLE(emul, EMUL_DT_NAME_GET(node_id)) __used = { \
150 : .init = (init_fn), \
151 : .dev = DEVICE_DT_GET(node_id), \
152 : .cfg = (cfg_ptr), \
153 : .data = (data_ptr), \
154 : .bus_type = Z_EMUL_BUS(node_id, EMUL_BUS_TYPE_I2C, EMUL_BUS_TYPE_ESPI, \
155 : EMUL_BUS_TYPE_SPI, EMUL_BUS_TYPE_MSPI, EMUL_BUS_TYPE_UART, \
156 : EMUL_BUS_TYPE_NONE), \
157 : .bus = {.Z_EMUL_BUS(node_id, i2c, espi, spi, mspi, uart, none) = \
158 : &(Z_EMUL_REG_BUS_IDENTIFIER(node_id))}, \
159 : .backend_api = (_backend_api), \
160 : };
161 :
162 : /**
163 : * @brief Like EMUL_DT_DEFINE(), but uses an instance of a DT_DRV_COMPAT compatible instead of a
164 : * node identifier.
165 : *
166 : * @param inst instance number. The @p node_id argument to EMUL_DT_DEFINE is set to
167 : * <tt>DT_DRV_INST(inst)</tt>.
168 : * @param ... other parameters as expected by EMUL_DT_DEFINE.
169 : */
170 1 : #define EMUL_DT_INST_DEFINE(inst, ...) EMUL_DT_DEFINE(DT_DRV_INST(inst), __VA_ARGS__)
171 :
172 : /**
173 : * @brief Get a <tt>const struct emul*</tt> from a devicetree node identifier
174 : *
175 : * @details Returns a pointer to an emulator object created from a devicetree
176 : * node, if any device was allocated by an emulator implementation.
177 : *
178 : * If no such device was allocated, this will fail at linker time. If you get an
179 : * error that looks like <tt>undefined reference to __device_dts_ord_<N></tt>,
180 : * that is what happened. Check to make sure your emulator implementation is
181 : * being compiled, usually by enabling the Kconfig options it requires.
182 : *
183 : * @param node_id A devicetree node identifier
184 : * @return A pointer to the emul object created for that node
185 : */
186 1 : #define EMUL_DT_GET(node_id) (&EMUL_DT_NAME_GET(node_id))
187 :
188 : /**
189 : * @brief Utility macro to obtain an optional reference to an emulator
190 : *
191 : * If the node identifier refers to a node with status `okay`, this returns `EMUL_DT_GET(node_id)`.
192 : * Otherwise, it returns `NULL`.
193 : *
194 : * @param node_id A devicetree node identifier
195 : * @return a @ref emul reference for the node identifier, which may be `NULL`.
196 : */
197 1 : #define EMUL_DT_GET_OR_NULL(node_id) \
198 : COND_CODE_1(DT_NODE_HAS_STATUS_OKAY(node_id), (EMUL_DT_GET(node_id)), (NULL))
199 :
200 : /**
201 : * @brief Set up a list of emulators
202 : *
203 : * @param dev Device the emulators are attached to (e.g. an I2C controller)
204 : * @return 0 if OK
205 : * @return negative value on error
206 : */
207 1 : int emul_init_for_bus(const struct device *dev);
208 :
209 : /**
210 : * @brief Retrieve the emul structure for an emulator by name
211 : *
212 : * @details Emulator objects are created via the EMUL_DT_DEFINE() macro and placed in memory by the
213 : * linker. If the emulator structure is needed for custom API calls, it can be retrieved by the name
214 : * that the emulator exposes to the system (this is the devicetree node's label by default).
215 : *
216 : * @param name Emulator name to search for. A null pointer, or a pointer to an
217 : * empty string, will cause NULL to be returned.
218 : *
219 : * @return pointer to emulator structure; NULL if not found or cannot be used.
220 : */
221 1 : const struct emul *emul_get_binding(const char *name);
222 :
223 : /**
224 : * @}
225 : */
226 :
227 : #define Z_MAYBE_EMUL_DECLARE_INTERNAL(node_id) extern const struct emul EMUL_DT_NAME_GET(node_id);
228 :
229 0 : DT_FOREACH_STATUS_OKAY_NODE(Z_MAYBE_EMUL_DECLARE_INTERNAL);
230 :
231 : #ifdef __cplusplus
232 : }
233 : #endif /* __cplusplus */
234 :
235 : #endif /* ZEPHYR_INCLUDE_DRIVERS_EMUL_H_ */
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