1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
/*
* Remote Laboratory FPGA Server GPMC Interface (Beaglebone Black)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* (c) 2012-2019 Timothy Pearson
* Raptor Engineering
* http://www.raptorengineeringinc.com
*/
/** BEGIN: Low-Level I/O Implementation **/
// Beaglebone Black GPMC driver
#include <sys/time.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#define MEMORY_SPACE_ADDRESS_BITS 16
#define GPMC_BASE 0x50000000
#define GPMC_REGLEN 0x10000000
#define GPMC_CHIPSELECTCONFIGDISPLACEMENT (0x30 / 4)
#define GPMC_CONFIG (0x50 / 4)
#define GPMC_CONFIG1 (0x60 / 4)
#define GPMC_CONFIG2 (0x64 / 4)
#define GPMC_CONFIG3 (0x68 / 4)
#define GPMC_CONFIG4 (0x6c / 4)
#define GPMC_CONFIG5 (0x70 / 4)
#define GPMC_CONFIG6 (0x74 / 4)
#define GPMC_CONFIG7 (0x78 / 4)
#define MEMORY_SIZE (1 << MEMORY_SPACE_ADDRESS_BITS)
int mem_fd = 0;
int gpmc_mem_fd = 0;
char *gpio_mem, *gpio_map, *gpmc_map;
// I/O access
volatile unsigned int *gpio = NULL;
volatile unsigned char *gpio_char = NULL;
volatile unsigned int *gpmc = NULL;
void gpmc_mapregisters() {
/* open /dev/mem */
if ((gpmc_mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
printf("[FATAL] can't open /dev/mem\n");
return;
}
/* mmap GPMC */
gpmc_map = (char *)mmap(
0,
GPMC_REGLEN,
PROT_READ|PROT_WRITE,
MAP_SHARED,
gpmc_mem_fd,
GPMC_BASE
);
if (gpmc_map == MAP_FAILED) {
printf("[FATAL] mmap error %p\n", gpmc_map);
return;
}
// Always use volatile pointer!
gpmc = (volatile unsigned *)gpmc_map;
}
void gpmc_unmapregisters() {
munmap((void*) gpmc, GPMC_REGLEN);
if (gpmc_mem_fd != -1) {
close(gpmc_mem_fd);
}
}
void gpmc_setup(void) {
gpmc_mapregisters();
if (gpmc != NULL) {
int chipselect = 0;
int displacement = GPMC_CHIPSELECTCONFIGDISPLACEMENT * chipselect;
// disable before playing with the registers
*(gpmc + displacement + GPMC_CONFIG7) = 0x00000000;
// *(gpmc + displacement + GPMC_CONFIG) = 0x00000000; // Unlimited address space
// *(gpmc + displacement + GPMC_CONFIG1) = 0x00000000; // No burst, async, 8-bit, non multiplexed
// *(gpmc + displacement + GPMC_CONFIG2) = 0x00001000; // Assert CS on fclk0, deassert CS on fclk16
// *(gpmc + displacement + GPMC_CONFIG3) = 0x00000400; // Assert ADV on fclk 0, deassert ADV on fclk 4
// *(gpmc + displacement + GPMC_CONFIG4) = 0x0c041004; // Assert WE on fclk4, deassert WE on fclk12, assert OE on fclk4, deassert OE on fclk16
// *(gpmc + displacement + GPMC_CONFIG5) = 0x000c1010; // Data valid on fclk 12, cycle time 16 fclks
// *(gpmc + displacement + GPMC_CONFIG6) = 0x00000000; // No back to back cycle restrictions
// *(gpmc + displacement + GPMC_CONFIG7) = 0x00000e50; // CS0: Set base address 0x10000000, 32MB region, and enable CS
// Use slower clocking to reduce errors in wire nest prototype
*(gpmc + displacement + GPMC_CONFIG) = 0x00000000; // Unlimited address space
*(gpmc + displacement + GPMC_CONFIG1) = 0x00000000; // No burst, async, 8-bit, non multiplexed
*(gpmc + displacement + GPMC_CONFIG2) = 0x00001f00; // Assert CS on fclk0, deassert CS on fclk31
*(gpmc + displacement + GPMC_CONFIG3) = 0x00000400; // Assert ADV on fclk 0, deassert ADV on fclk 4
*(gpmc + displacement + GPMC_CONFIG4) = 0x1f041f04; // Assert WE on fclk4, deassert WE on fclk31, assert OE on fclk4, deassert OE on fclk31
*(gpmc + displacement + GPMC_CONFIG5) = 0x00101f1f; // Data valid on fclk 16, cycle time 31 fclks
*(gpmc + displacement + GPMC_CONFIG6) = 0x00000000; // No back to back cycle restrictions
*(gpmc + displacement + GPMC_CONFIG7) = 0x00000e50; // CS0: Set base address 0x10000000, 32MB region, and enable CS
gpmc_unmapregisters();
}
}
int setup_gpmc_bbb(void) {
/* open /dev/mem */
if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
printf("[FATAL] can't open /dev/mem\n");
return -1;
}
/* mmap GPIO */
gpio_map = (char *)mmap(
0,
MEMORY_SIZE,
PROT_READ|PROT_WRITE,
MAP_SHARED,
mem_fd,
0x10000000
);
if (gpio_map == MAP_FAILED) {
printf("[FATAL] mmap error %p\n", gpio_map);
return -1;
}
// Always use volatile pointers!
gpio = (volatile unsigned *)gpio_map;
gpio_char = (volatile unsigned char *)gpio_map;
return 0;
}
int shutdown_gpmc_bbb(void) {
return 0;
}
void write_gpmc(unsigned int register_offset, unsigned char data) {
*(gpio_char + register_offset) = data;
}
unsigned char read_gpmc(unsigned int register_offset) {
return *(gpio_char + register_offset);
}
void write_gpmc_uint16_t(unsigned int register_offset, uint16_t data) {
register_offset = register_offset * 2;
*(gpio_char + register_offset + 0) = ((data & 0xff00) >> 8);
*(gpio_char + register_offset + 1) = ((data & 0x00ff) >> 0);
}
uint16_t read_gpmc_uint16_t(unsigned int register_offset) {
uint16_t result = 0;
register_offset = register_offset * 2;
result = result | ((uint16_t)(*(gpio_char + register_offset + 0)) << 8);
result = result | ((uint16_t)(*(gpio_char + register_offset + 1)) << 0);
return result;
}
void write_gpmc_uint64_t(unsigned int register_offset, uint64_t data) {
register_offset = register_offset * 8;
*(gpio_char + register_offset + 0) = ((data & 0xff00000000000000) >> 56);
*(gpio_char + register_offset + 1) = ((data & 0x00ff000000000000) >> 48);
*(gpio_char + register_offset + 2) = ((data & 0x0000ff0000000000) >> 40);
*(gpio_char + register_offset + 3) = ((data & 0x000000ff00000000) >> 32);
*(gpio_char + register_offset + 4) = ((data & 0x00000000ff000000) >> 24);
*(gpio_char + register_offset + 5) = ((data & 0x0000000000ff0000) >> 16);
*(gpio_char + register_offset + 6) = ((data & 0x000000000000ff00) >> 8);
*(gpio_char + register_offset + 7) = ((data & 0x00000000000000ff) >> 0);
}
uint64_t read_gpmc_uint64_t(unsigned int register_offset) {
uint64_t result = 0;
register_offset = register_offset * 8;
result = result | ((uint64_t)(*(gpio_char + register_offset + 0)) << 56);
result = result | ((uint64_t)(*(gpio_char + register_offset + 1)) << 48);
result = result | ((uint64_t)(*(gpio_char + register_offset + 2)) << 40);
result = result | ((uint64_t)(*(gpio_char + register_offset + 3)) << 32);
result = result | ((uint64_t)(*(gpio_char + register_offset + 4)) << 24);
result = result | ((uint64_t)(*(gpio_char + register_offset + 5)) << 16);
result = result | ((uint64_t)(*(gpio_char + register_offset + 6)) << 8);
result = result | ((uint64_t)(*(gpio_char + register_offset + 7)) << 0);
return result;
}
void memcpy_from_gpmc(char* destination, unsigned int register_offset, unsigned int length) {
unsigned int i;
for (i=0; i<length; i++) {
*destination = *(gpio_char + register_offset);
destination++;
register_offset++;
}
}
void memcpy_to_gpmc(char* source, unsigned int register_offset, unsigned int length) {
unsigned int i;
for (i=0; i<length; i++) {
*(gpio_char + register_offset) = *source;
source++;
register_offset++;
}
}
/** END: Low-Level I/O Implementation **/
|
