xref: /openbmc/qemu/include/hw/register.h (revision fe7f9b8e)
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 
18 typedef struct RegisterInfo RegisterInfo;
19 typedef struct RegisterAccessInfo RegisterAccessInfo;
20 typedef struct RegisterInfoArray RegisterInfoArray;
21 
22 /**
23  * Access description for a register that is part of guest accessible device
24  * state.
25  *
26  * @name: String name of the register
27  * @ro: whether or not the bit is read-only
28  * @w1c: bits with the common write 1 to clear semantic.
29  * @reset: reset value.
30  * @cor: Bits that are clear on read
31  * @rsvd: Bits that are reserved and should not be changed
32  *
33  * @pre_write: Pre write callback. Passed the value that's to be written,
34  * immediately before the actual write. The returned value is what is written,
35  * giving the handler a chance to modify the written value.
36  * @post_write: Post write callback. Passed the written value. Most write side
37  * effects should be implemented here. This is called during device reset.
38  *
39  * @post_read: Post read callback. Passes the value that is about to be returned
40  * for a read. The return value from this function is what is ultimately read,
41  * allowing this function to modify the value before return to the client.
42  */
43 
44 struct RegisterAccessInfo {
45     const char *name;
46     uint64_t ro;
47     uint64_t w1c;
48     uint64_t reset;
49     uint64_t cor;
50     uint64_t rsvd;
51     uint64_t unimp;
52 
53     uint64_t (*pre_write)(RegisterInfo *reg, uint64_t val);
54     void (*post_write)(RegisterInfo *reg, uint64_t val);
55 
56     uint64_t (*post_read)(RegisterInfo *reg, uint64_t val);
57 
58     hwaddr addr;
59 };
60 
61 /**
62  * A register that is part of guest accessible state
63  * @data: pointer to the register data. Will be cast
64  * to the relevant uint type depending on data_size.
65  * @data_size: Size of the register in bytes. Must be
66  * 1, 2, 4 or 8
67  *
68  * @access: Access description of this register
69  *
70  * @debug: Whether or not verbose debug is enabled
71  * @prefix: String prefix for log and debug messages
72  *
73  * @opaque: Opaque data for the register
74  */
75 
76 struct RegisterInfo {
77     /* <private> */
78     DeviceState parent_obj;
79 
80     /* <public> */
81     void *data;
82     int data_size;
83 
84     const RegisterAccessInfo *access;
85 
86     void *opaque;
87 };
88 
89 #define TYPE_REGISTER "qemu,register"
90 #define REGISTER(obj) OBJECT_CHECK(RegisterInfo, (obj), TYPE_REGISTER)
91 
92 /**
93  * This structure is used to group all of the individual registers which are
94  * modeled using the RegisterInfo structure.
95  *
96  * @r is an array containing of all the relevant RegisterInfo structures.
97  *
98  * @num_elements is the number of elements in the array r
99  *
100  * @mem: optional Memory region for the register
101  */
102 
103 struct RegisterInfoArray {
104     MemoryRegion mem;
105 
106     int num_elements;
107     RegisterInfo **r;
108 
109     bool debug;
110     const char *prefix;
111 };
112 
113 /**
114  * write a value to a register, subject to its restrictions
115  * @reg: register to write to
116  * @val: value to write
117  * @we: write enable mask
118  * @prefix: The device prefix that should be printed before the register name
119  * @debug: Should the write operation debug information be printed?
120  */
121 
122 void register_write(RegisterInfo *reg, uint64_t val, uint64_t we,
123                     const char *prefix, bool debug);
124 
125 /**
126  * read a value from a register, subject to its restrictions
127  * @reg: register to read from
128  * @re: read enable mask
129  * @prefix: The device prefix that should be printed before the register name
130  * @debug: Should the read operation debug information be printed?
131  * returns: value read
132  */
133 
134 uint64_t register_read(RegisterInfo *reg, uint64_t re, const char* prefix,
135                        bool debug);
136 
137 /**
138  * Resets a register. This will also call the post_write hook if it exists.
139  * @reg: The register to reset.
140  */
141 
142 void register_reset(RegisterInfo *reg);
143 
144 /**
145  * Initialize a register.
146  * @reg: Register to initialize
147  */
148 
149 void register_init(RegisterInfo *reg);
150 
151 /**
152  * Memory API MMIO write handler that will write to a Register API register.
153  * @opaque: RegisterInfo to write to
154  * @addr: Address to write
155  * @value: Value to write
156  * @size: Number of bytes to write
157  */
158 
159 void register_write_memory(void *opaque, hwaddr addr, uint64_t value,
160                            unsigned size);
161 
162 /**
163  * Memory API MMIO read handler that will read from a Register API register.
164  * @opaque: RegisterInfo to read from
165  * @addr: Address to read
166  * @size: Number of bytes to read
167  * returns: Value read from register
168  */
169 
170 uint64_t register_read_memory(void *opaque, hwaddr addr, unsigned size);
171 
172 /**
173  * Init a block of registers into a container MemoryRegion. A
174  * number of constant register definitions are parsed to create a corresponding
175  * array of RegisterInfo's.
176  *
177  * @owner: device owning the registers
178  * @rae: Register definitions to init
179  * @num: number of registers to init (length of @rae)
180  * @ri: Register array to init, must already be allocated
181  * @data: Array to use for register data, must already be allocated
182  * @ops: Memory region ops to access registers.
183  * @debug enabled: turn on/off verbose debug information
184  * returns: A structure containing all of the registers and an initialized
185  *          memory region (r_array->mem) the caller should add to a container.
186  */
187 
188 RegisterInfoArray *register_init_block32(DeviceState *owner,
189                                          const RegisterAccessInfo *rae,
190                                          int num, RegisterInfo *ri,
191                                          uint32_t *data,
192                                          const MemoryRegionOps *ops,
193                                          bool debug_enabled,
194                                          uint64_t memory_size);
195 
196 /**
197  * This function should be called to cleanup the registers that were initialized
198  * when calling register_init_block32(). This function should only be called
199  * from the device's instance_finalize function.
200  *
201  * Any memory operations that the device performed that require cleanup (such
202  * as creating subregions) need to be called before calling this function.
203  *
204  * @r_array: A structure containing all of the registers, as returned by
205  *           register_init_block32()
206  */
207 
208 void register_finalize_block(RegisterInfoArray *r_array);
209 
210 #endif
211