xref: /openbmc/qemu/include/hw/register.h (revision db1015e92e04835c9eb50c29625fe566d1202dbd)
1 /*
2  * Register Definition API
3  *
4  * Copyright (c) 2016 Xilinx Inc.
5  * Copyright (c) 2013 Peter Crosthwaite <peter.crosthwaite@xilinx.com>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2.  See
8  * the COPYING file in the top-level directory.
9  */
10 
11 #ifndef REGISTER_H
12 #define REGISTER_H
13 
14 #include "hw/qdev-core.h"
15 #include "exec/memory.h"
16 #include "hw/registerfields.h"
17 #include "qom/object.h"
18 
19 typedef struct RegisterInfo RegisterInfo;
20 typedef struct RegisterAccessInfo RegisterAccessInfo;
21 typedef struct RegisterInfoArray RegisterInfoArray;
22 
23 /**
24  * Access description for a register that is part of guest accessible device
25  * state.
26  *
27  * @name: String name of the register
28  * @ro: whether or not the bit is read-only
29  * @w1c: bits with the common write 1 to clear semantic.
30  * @reset: reset value.
31  * @cor: Bits that are clear on read
32  * @rsvd: Bits that are reserved and should not be changed
33  *
34  * @pre_write: Pre write callback. Passed the value that's to be written,
35  * immediately before the actual write. The returned value is what is written,
36  * giving the handler a chance to modify the written value.
37  * @post_write: Post write callback. Passed the written value. Most write side
38  * effects should be implemented here. This is called during device reset.
39  *
40  * @post_read: Post read callback. Passes the value that is about to be returned
41  * for a read. The return value from this function is what is ultimately read,
42  * allowing this function to modify the value before return to the client.
43  */
44 
45 struct RegisterAccessInfo {
46     const char *name;
47     uint64_t ro;
48     uint64_t w1c;
49     uint64_t reset;
50     uint64_t cor;
51     uint64_t rsvd;
52     uint64_t unimp;
53 
54     uint64_t (*pre_write)(RegisterInfo *reg, uint64_t val);
55     void (*post_write)(RegisterInfo *reg, uint64_t val);
56 
57     uint64_t (*post_read)(RegisterInfo *reg, uint64_t val);
58 
59     hwaddr addr;
60 };
61 
62 /**
63  * A register that is part of guest accessible state
64  * @data: pointer to the register data. Will be cast
65  * to the relevant uint type depending on data_size.
66  * @data_size: Size of the register in bytes. Must be
67  * 1, 2, 4 or 8
68  *
69  * @access: Access description of this register
70  *
71  * @debug: Whether or not verbose debug is enabled
72  * @prefix: String prefix for log and debug messages
73  *
74  * @opaque: Opaque data for the register
75  */
76 
77 struct RegisterInfo {
78     /* <private> */
79     DeviceState parent_obj;
80 
81     /* <public> */
82     void *data;
83     int data_size;
84 
85     const RegisterAccessInfo *access;
86 
87     void *opaque;
88 };
89 
90 #define TYPE_REGISTER "qemu,register"
91 #define REGISTER(obj) OBJECT_CHECK(RegisterInfo, (obj), TYPE_REGISTER)
92 
93 /**
94  * This structure is used to group all of the individual registers which are
95  * modeled using the RegisterInfo structure.
96  *
97  * @r is an array containing of all the relevant RegisterInfo structures.
98  *
99  * @num_elements is the number of elements in the array r
100  *
101  * @mem: optional Memory region for the register
102  */
103 
104 struct RegisterInfoArray {
105     MemoryRegion mem;
106 
107     int num_elements;
108     RegisterInfo **r;
109 
110     bool debug;
111     const char *prefix;
112 };
113 
114 /**
115  * write a value to a register, subject to its restrictions
116  * @reg: register to write to
117  * @val: value to write
118  * @we: write enable mask
119  * @prefix: The device prefix that should be printed before the register name
120  * @debug: Should the write operation debug information be printed?
121  */
122 
123 void register_write(RegisterInfo *reg, uint64_t val, uint64_t we,
124                     const char *prefix, bool debug);
125 
126 /**
127  * read a value from a register, subject to its restrictions
128  * @reg: register to read from
129  * @re: read enable mask
130  * @prefix: The device prefix that should be printed before the register name
131  * @debug: Should the read operation debug information be printed?
132  * returns: value read
133  */
134 
135 uint64_t register_read(RegisterInfo *reg, uint64_t re, const char* prefix,
136                        bool debug);
137 
138 /**
139  * Resets a register. This will also call the post_write hook if it exists.
140  * @reg: The register to reset.
141  */
142 
143 void register_reset(RegisterInfo *reg);
144 
145 /**
146  * Initialize a register.
147  * @reg: Register to initialize
148  */
149 
150 void register_init(RegisterInfo *reg);
151 
152 /**
153  * Memory API MMIO write handler that will write to a Register API register.
154  * @opaque: RegisterInfo to write to
155  * @addr: Address to write
156  * @value: Value to write
157  * @size: Number of bytes to write
158  */
159 
160 void register_write_memory(void *opaque, hwaddr addr, uint64_t value,
161                            unsigned size);
162 
163 /**
164  * Memory API MMIO read handler that will read from a Register API register.
165  * @opaque: RegisterInfo to read from
166  * @addr: Address to read
167  * @size: Number of bytes to read
168  * returns: Value read from register
169  */
170 
171 uint64_t register_read_memory(void *opaque, hwaddr addr, unsigned size);
172 
173 /**
174  * Init a block of registers into a container MemoryRegion. A
175  * number of constant register definitions are parsed to create a corresponding
176  * array of RegisterInfo's.
177  *
178  * @owner: device owning the registers
179  * @rae: Register definitions to init
180  * @num: number of registers to init (length of @rae)
181  * @ri: Register array to init, must already be allocated
182  * @data: Array to use for register data, must already be allocated
183  * @ops: Memory region ops to access registers.
184  * @debug enabled: turn on/off verbose debug information
185  * @memory_size: Size of the memory region
186  * returns: A structure containing all of the registers and an initialized
187  *          memory region (r_array->mem) the caller should add to a container.
188  */
189 
190 RegisterInfoArray *register_init_block8(DeviceState *owner,
191                                         const RegisterAccessInfo *rae,
192                                         int num, RegisterInfo *ri,
193                                         uint8_t *data,
194                                         const MemoryRegionOps *ops,
195                                         bool debug_enabled,
196                                         uint64_t memory_size);
197 
198 RegisterInfoArray *register_init_block32(DeviceState *owner,
199                                          const RegisterAccessInfo *rae,
200                                          int num, RegisterInfo *ri,
201                                          uint32_t *data,
202                                          const MemoryRegionOps *ops,
203                                          bool debug_enabled,
204                                          uint64_t memory_size);
205 
206 /**
207  * This function should be called to cleanup the registers that were initialized
208  * when calling register_init_block32(). This function should only be called
209  * from the device's instance_finalize function.
210  *
211  * Any memory operations that the device performed that require cleanup (such
212  * as creating subregions) need to be called before calling this function.
213  *
214  * @r_array: A structure containing all of the registers, as returned by
215  *           register_init_block32()
216  */
217 
218 void register_finalize_block(RegisterInfoArray *r_array);
219 
220 #endif
221