/
read_in_memory.c
284 lines (216 loc) · 5.94 KB
/
read_in_memory.c
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
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
/*
minimal_gpio.c
2015-02-10
Public Domain
*/
/*
gcc -o minimal_gpio minimal_gpio.c
sudo ./minimal_gpio
*/
#include <stdio.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <math.h>
static volatile uint32_t piModel = 1;
static volatile uint32_t piPeriphBase = 0x20000000;
static volatile uint32_t piBusAddr = 0x40000000;
#define SYST_BASE (piPeriphBase + 0x003000)
#define DMA_BASE (piPeriphBase + 0x007000)
#define CLK_BASE (piPeriphBase + 0x101000)
#define GPIO_BASE (piPeriphBase + 0x200000)
#define UART0_BASE (piPeriphBase + 0x201000)
#define PCM_BASE (piPeriphBase + 0x203000)
#define SPI0_BASE (piPeriphBase + 0x204000)
#define I2C0_BASE (piPeriphBase + 0x205000)
#define PWM_BASE (piPeriphBase + 0x20C000)
#define UART1_BASE (piPeriphBase + 0x215000)
#define I2C1_BASE (piPeriphBase + 0x804000)
#define I2C2_BASE (piPeriphBase + 0x805000)
#define DMA15_BASE (piPeriphBase + 0xE05000)
#define DMA_LEN 0x1000 /* allow access to all channels */
#define CLK_LEN 0xA8
#define GPIO_LEN 0xB4
#define SYST_LEN 0x1C
#define PCM_LEN 0x24
#define PWM_LEN 0x28
#define I2C_LEN 0x1C
#define GPSET0 7
#define GPSET1 8
#define GPCLR0 10
#define GPCLR1 11
#define GPLEV0 13
#define GPLEV1 14
#define GPPUD 37
#define GPPUDCLK0 38
#define GPPUDCLK1 39
#define SYST_CS 0
#define SYST_CLO 1
#define SYST_CHI 2
static volatile uint32_t *gpioReg = MAP_FAILED;
static volatile uint32_t *systReg = MAP_FAILED;
#define PI_BANK (gpio>>5)
#define PI_BIT (1<<(gpio&0x1F))
/* gpio modes. */
#define PI_INPUT 0
#define PI_OUTPUT 1
#define PI_ALT0 4
#define PI_ALT1 5
#define PI_ALT2 6
#define PI_ALT3 7
#define PI_ALT4 3
#define PI_ALT5 2
void gpioSetMode(unsigned gpio, unsigned mode)
{
int reg, shift;
reg = gpio/10;
shift = (gpio%10) * 3;
gpioReg[reg] = (gpioReg[reg] & ~(7<<shift)) | (mode<<shift);
}
int gpioGetMode(unsigned gpio)
{
int reg, shift;
reg = gpio/10;
shift = (gpio%10) * 3;
return (*(gpioReg + reg) >> shift) & 7;
}
/* Values for pull-ups/downs off, pull-down and pull-up. */
#define PI_PUD_OFF 0
#define PI_PUD_DOWN 1
#define PI_PUD_UP 2
void gpioSetPullUpDown(unsigned gpio, unsigned pud)
{
*(gpioReg + GPPUD) = pud;
usleep(20);
*(gpioReg + GPPUDCLK0 + PI_BANK) = PI_BIT;
usleep(20);
*(gpioReg + GPPUD) = 0;
*(gpioReg + GPPUDCLK0 + PI_BANK) = 0;
}
int gpioRead(unsigned gpio)
{
if ((*(gpioReg + GPLEV0 + PI_BANK) & PI_BIT) != 0) return 1;
else return 0;
}
void gpioWrite(unsigned gpio, unsigned level)
{
if (level == 0) *(gpioReg + GPCLR0 + PI_BANK) = PI_BIT;
else *(gpioReg + GPSET0 + PI_BANK) = PI_BIT;
}
void gpioTrigger(unsigned gpio, unsigned pulseLen, unsigned level)
{
if (level == 0) *(gpioReg + GPCLR0 + PI_BANK) = PI_BIT;
else *(gpioReg + GPSET0 + PI_BANK) = PI_BIT;
usleep(pulseLen);
if (level != 0) *(gpioReg + GPCLR0 + PI_BANK) = PI_BIT;
else *(gpioReg + GPSET0 + PI_BANK) = PI_BIT;
}
/* Bit (1<<x) will be set if gpio x is high. */
uint32_t gpioReadBank1(void) { return (*(gpioReg + GPLEV0)); }
uint32_t gpioReadBank2(void) { return (*(gpioReg + GPLEV1)); }
/* To clear gpio x bit or in (1<<x). */
void gpioClearBank1(uint32_t bits) { *(gpioReg + GPCLR0) = bits; }
void gpioClearBank2(uint32_t bits) { *(gpioReg + GPCLR1) = bits; }
/* To set gpio x bit or in (1<<x). */
void gpioSetBank1(uint32_t bits) { *(gpioReg + GPSET0) = bits; }
void gpioSetBank2(uint32_t bits) { *(gpioReg + GPSET1) = bits; }
unsigned gpioHardwareRevision(void)
{
static unsigned rev = 0;
FILE * filp;
char buf[512];
char term;
int chars=4; /* number of chars in revision string */
if (rev) return rev;
piModel = 0;
filp = fopen ("/proc/cpuinfo", "r");
if (filp != NULL)
{
while (fgets(buf, sizeof(buf), filp) != NULL)
{
if (piModel == 0)
{
if (!strncasecmp("model name", buf, 10))
{
if (strstr (buf, "ARMv6") != NULL)
{
piModel = 1;
chars = 4;
piPeriphBase = 0x20000000;
piBusAddr = 0x40000000;
}
else if (strstr (buf, "ARMv7") != NULL)
{
piModel = 2;
chars = 6;
piPeriphBase = 0x3F000000;
piBusAddr = 0xC0000000;
}
}
}
if (!strncasecmp("revision", buf, 8))
{
if (sscanf(buf+strlen(buf)-(chars+1),
"%x%c", &rev, &term) == 2)
{
if (term != '\n') rev = 0;
}
}
}
fclose(filp);
}
return rev;
}
/* Returns the number of microseconds after system boot. Wraps around
after 1 hour 11 minutes 35 seconds.
*/
uint32_t gpioTick(void) { return systReg[SYST_CLO]; }
/* Map in registers. */
static uint32_t * initMapMem(int fd, uint32_t addr, uint32_t len)
{
return (uint32_t *) mmap(0, len,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_SHARED|MAP_LOCKED,
fd, addr);
}
int gpioInitialise(void)
{
int fd;
gpioHardwareRevision(); /* sets piModel, needed for peripherals address */
fd = open("/dev/mem", O_RDWR | O_SYNC) ;
if (fd < 0)
{
fprintf(stderr,
"This program needs root privileges. Try using sudo\n");
return -1;
}
gpioReg = initMapMem(fd, GPIO_BASE, GPIO_LEN);
systReg = initMapMem(fd, SYST_BASE, SYST_LEN);
close(fd);
if ((gpioReg == MAP_FAILED) ||
(systReg == MAP_FAILED))
{
fprintf(stderr,
"Bad, mmap failed\n");
return -1;
}
return 0;
}
main()
{
int i;
int j;
if (gpioInitialise() < 0) return 1;
i=5; // which pin
FILE *f1 = fopen("client.data", "wb");
int total;
total = 0;
while (total<5000000) {
j=gpioRead(i);
total+=1;
}
}