xref: /optee_os/core/include/kernel/dt_driver.h (revision 9e3c57c88b0cdd41de57107725621c8c0857a838)
1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*
3  * Copyright (c) 2021, Linaro Limited
4  * Copyright (c) 2021, Bootlin
5  * Copyright (c) 2021, STMicroelectronics
6  */
7 
8 #ifndef __DT_DRIVER_H
9 #define __DT_DRIVER_H
10 
11 #include <kernel/dt.h>
12 #include <stdint.h>
13 #include <sys/queue.h>
14 #include <tee_api_types.h>
15 
16 /*
17  * Type indentifiers for registered device drivers consumer can query
18  *
19  * DT_DRIVER_NOTYPE Generic type for when no generic FDT parsing is supported
20  * DT_DRIVER_UART   UART driver currently designed for console means
21  * DT_DRIVER_CLK    Clock controller using generic clock DT bindings
22  * DT_DRIVER_RSTCTRL Reset controller using generic reset DT bindings
23  * DT_DRIVER_I2C    I2C bus controlle using generic I2C bus DT bindings
24  */
25 enum dt_driver_type {
26 	DT_DRIVER_NOTYPE,
27 	DT_DRIVER_UART,
28 	DT_DRIVER_CLK,
29 	DT_DRIVER_RSTCTRL,
30 	DT_DRIVER_I2C,
31 };
32 
33 /*
34  * dt_driver_probe_func - Callback probe function for a driver.
35  *
36  * @fdt: FDT base address
37  * @nodeoffset: Offset of the node in the FDT
38  * @compat_data: Data registered for the compatible that probed the device
39  *
40  * Return TEE_SUCCESS on successful probe,
41  *	TEE_ERROR_DEFER_DRIVER_INIT if probe must be deferred
42  *	TEE_ERROR_ITEM_NOT_FOUND when no driver matched node's compatible string
43  *	Any other TEE_ERROR_* compliant code.
44  */
45 typedef TEE_Result (*dt_driver_probe_func)(const void *fdt, int nodeoffset,
46 					   const void *compat_data);
47 
48 /*
49  * Driver instance registered to be probed on compatible node found in the DT.
50  *
51  * @name: Driver name
52  * @type: Drive type
53  * @match_table: Compatible matching identifiers, null terminated
54  * @driver: Driver private reference or NULL
55  * @probe: Probe callback (see dt_driver_probe_func) or NULL
56  */
57 struct dt_driver {
58 	const char *name;
59 	enum dt_driver_type type;
60 	const struct dt_device_match *match_table; /* null-terminated */
61 	const void *driver;
62 	TEE_Result (*probe)(const void *fdt, int node, const void *compat_data);
63 };
64 
65 #define DEFINE_DT_DRIVER(name) \
66 		SCATTERED_ARRAY_DEFINE_PG_ITEM(dt_drivers, struct dt_driver)
67 
68 #define for_each_dt_driver(drv) \
69 	for (drv = SCATTERED_ARRAY_BEGIN(dt_drivers, struct dt_driver); \
70 	     drv < SCATTERED_ARRAY_END(dt_drivers, struct dt_driver); \
71 	     drv++)
72 
73 /* Opaque reference to DT driver device provider instance */
74 struct dt_driver_provider;
75 
76 /**
77  * struct dt_driver_phandle_args - Devicetree phandle arguments
78  * @fdt: Device-tree to work on
79  * @phandle_node: Node pointed by the specifier phandle
80  * @args_count: Count of cells for the device
81  * @args: Device consumer specifiers
82  */
83 struct dt_driver_phandle_args {
84 	const void *fdt;
85 	int phandle_node;
86 	int args_count;
87 	uint32_t args[];
88 };
89 
90 /*
91  * get_of_device_func - Callback function for returning a driver private
92  *	instance based on a FDT phandle with possible arguments and the
93  *	registered dt_driver private data reference.
94  *
95  * @parg: phandle argument(s) referencing the device in the FDT.
96  * @data: driver private data registered in struct dt_driver.
97  * @res: Output result code of the operation:
98  *	TEE_SUCCESS in case of success
99  *	TEE_ERROR_DEFER_DRIVER_INIT if device driver is not yet initialized
100  *	Any TEE_Result compliant code in case of error.
101  *
102  * Return a device opaque reference, e.g. a struct clk pointer for a clock
103  * driver, or NULL if not found in which case @res provides the error code.
104  */
105 typedef void *(*get_of_device_func)(struct dt_driver_phandle_args *parg,
106 				    void *data, TEE_Result *res);
107 
108 /**
109  * dt_driver_register_provider - Register a driver provider
110  *
111  * @fdt: Device tree to work on
112  * @nodeoffset: Node offset in the FDT
113  * @get_of_device: Function to match the devicetree with a device instance
114  * @data: Data which will be passed to the @get_of_device callback
115  * @type: Driver type
116  *
117  * @get_of_device returns a void *. Driver provider is expected to
118  * include a shim helper to cast to device reference into provider driver
119  * target structure reference (e.g (struct clk *) for clock devices).
120  */
121 TEE_Result dt_driver_register_provider(const void *fdt, int nodeoffset,
122 				       get_of_device_func get_of_device,
123 				       void *data, enum dt_driver_type type);
124 
125 /*
126  * dt_driver_device_from_node_idx_prop - Return a device instance based on a
127  *	property name and FDT information
128  *
129  * @prop_name: DT property name, e.g. "clocks" for clock resources
130  * @fdt: FDT base address
131  * @nodeoffset: node offset in the FDT
132  * @prop_idx: index of the phandle data in the property
133  * @type: Driver type
134  * @res: Output result code of the operation:
135  *	TEE_SUCCESS in case of success
136  *	TEE_ERROR_DEFER_DRIVER_INIT if device driver is not yet initialized
137  *	TEE_ERROR_ITEM_NOT_FOUND if prop_name does not match a property's name
138  *	Any TEE_Result compliant code in case of error.
139  *
140  * Return a device opaque reference, e.g. a struct clk pointer for a clock
141  * driver, or NULL if not found in which case @res provides the error code.
142  */
143 void *dt_driver_device_from_node_idx_prop(const char *prop_name,
144 					  const void *fdt, int nodeoffset,
145 					  unsigned int prop_idx,
146 					  enum dt_driver_type type,
147 					  TEE_Result *res);
148 
149 /*
150  * dt_driver_device_from_parent - Return a device instance based on the parent.
151  *	This is mainly used for the devices that are children of a controller
152  *	such as I2C, SPI and so on.
153  *
154  * @fdt: FDT base address
155  * @nodeoffset: node offset in the FDT
156  * @type: Driver type
157  * @res: Output result code of the operation:
158  *	TEE_SUCCESS in case of success
159  *	TEE_ERROR_DEFER_DRIVER_INIT if device driver is not yet initialized
160  *	Any TEE_Result compliant code in case of error.
161  *
162  * Return a device opaque reference, e.g. a struct i2c_dev pointer for a I2C bus
163  * driver, or NULL if not found in which case @res provides the error code.
164  */
165 void *dt_driver_device_from_parent(const void *fdt, int nodeoffset,
166 				   enum dt_driver_type type, TEE_Result *res);
167 
168 /*
169  * dt_driver_get_crypto() - Request crypto support for driver initialization
170  *
171  * Return TEE_SUCCESS if cryptography services are initialized, otherwise return
172  * TEE_ERROR_DEFER_DRIVER_INIT.
173  */
174 TEE_Result dt_driver_get_crypto(void);
175 
176 #ifdef CFG_DT
177 /* Inform DT driver probe sequence that core crypto support is initialized */
178 void dt_driver_crypt_init_complete(void);
179 #else
180 static inline void dt_driver_crypt_init_complete(void) {}
181 #endif
182 
183 /*
184  * Return driver provider reference from its node offset value in the FDT
185  */
186 struct dt_driver_provider *
187 dt_driver_get_provider_by_node(int nodeoffset, enum dt_driver_type type);
188 
189 /*
190  * Return driver provider reference from its phandle value in the FDT
191  */
192 struct dt_driver_provider *
193 dt_driver_get_provider_by_phandle(uint32_t phandle, enum dt_driver_type type);
194 
195 /*
196  * Return number cells used for phandle arguments by a driver provider
197  */
198 unsigned int dt_driver_provider_cells(struct dt_driver_provider *prv);
199 
200 /*
201  * dt_driver_probe_device_by_node - Probe matching driver to create a device
202  *	from a FDT node
203  *
204  * @fdt: FDT base address
205  * @nodeoffset: Node byte offset from FDT base
206  * @type: Target driver to match or DT_DRIVER_ANY
207  *
208  * Read the dt_driver database. Compatible list is looked up in the order
209  * of the FDT "compatible" property list. @type can be used to probe only
210  * specific drivers.
211  *
212  */
213 TEE_Result dt_driver_probe_device_by_node(const void *fdt, int nodeoffset,
214 					  enum dt_driver_type type);
215 
216 /*
217  * Get cells count of a device node given its dt_driver type
218  *
219  * @fdt: FDT base address
220  * @nodeoffset: Node offset on the FDT for the device
221  * @type: One of the supported DT_DRIVER_* value.
222  *
223  * Return a positive cell count value (>= 0) or a negative FDT_ error code
224  */
225 int fdt_get_dt_driver_cells(const void *fdt, int nodeoffset,
226 			    enum dt_driver_type type);
227 
228 /*
229  * Called by bus like nodes to propose a node for dt_driver probing
230  *
231  * @fdt: FDT base address
232  * @nodeoffset: Node offset on the FDT for the device
233  */
234 TEE_Result dt_driver_maybe_add_probe_node(const void *fdt, int nodeoffset);
235 
236 #ifdef CFG_DT_DRIVER_EMBEDDED_TEST
237 /*
238  * Return TEE_ERROR_NOT_IMPLEMENTED if test are not implemented
239  * otherwise return TEE_ERROR_GENERIC if some test has failed
240  * otherwise return TEE_SUCCESS (tests succeed or skipped)
241  */
242 TEE_Result dt_driver_test_status(void);
243 #else
244 static inline TEE_Result dt_driver_test_status(void)
245 {
246 	return TEE_ERROR_NOT_IMPLEMENTED;
247 }
248 #endif
249 
250 #endif /* __DT_DRIVER_H */
251