blob: 7f283e14eecfc7340b6e1210607985e15daa98b4 (
plain) (
blame)
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
|
#include <xc.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <usb.h>
#include <usb_device.h>
#include <usb_device_cdc.h>
#include "usb.h"
/***** Constants *****/
// Line coding
// See struct USB_CDC_LINE_CODING
enum {
DATA_RATE = 9600, // bps
CHAR_FORMAT = NUM_STOP_BITS_1,
PARITY_TYPE = PARITY_NONE,
DATA_BITS = 8,
};
/***** Types *****/
// A state is a function that executes the state's action and returns the next state.
typedef struct State {
struct State* (*next)(void);
} State;
/***** Function Declarations *****/
// States
static State *idleState(void);
static State *echoState(void);
static State *writeEepromState(void);
static State *readEepromState(void);
/***** Global Variables *****/
static uint8_t readBuf[CDC_DATA_OUT_EP_SIZE];
static uint8_t writeBuf[CDC_DATA_IN_EP_SIZE];
static uint8_t readLen = 0u;
/***** Function Definitions *****/
void
usbTask(void) {
static State state = {idleState};
USBDeviceTasks();
if (USBGetDeviceState() < CONFIGURED_STATE) {
return;
}
if (USBIsDeviceSuspended()) {
return;
}
if (USBUSARTIsTxTrfReady()) {
// Execute action and transition to next state
state = *state.next();
}
CDCTxService();
}
// Read (the start of) a command from USB.
// Leaves <args> at the beginning of the read buffer.
static State *
idleState(void) {
static State state;
uint8_t opcode;
state.next = idleState;
readLen = getsUSBUSART(readBuf, sizeof(readBuf));
if (readLen >= 2u) { // <opcode> <space> ...
opcode = readBuf[0u];
// skip <opcode> <space>
memmove(readBuf, readBuf+2u, readLen-2u);
readLen -= 2u;
switch (opcode) {
case 'e': state.next = echoState; break;
case 'w': state.next = writeEepromState; break;
case 'r': state.next = readEepromState; break;
default: break; // invalid command
}
}
return &state;
}
// Handle "e" echo command.
static State *
echoState(void) {
static State state;
uint8_t i;
state.next = echoState;
if (readLen == 0u) {
readLen = getsUSBUSART(readBuf, sizeof(readBuf));
}
for (i = 0u; i < readLen; i++) {
writeBuf[i] = readBuf[i];
if (readBuf[i] == '\n') {
// End of command
state.next = idleState;
i++;
break;
}
}
if (readLen > 0u) {
putUSBUSART(writeBuf, i);
}
readLen = 0u;
return &state;
}
// Handle "w" write eeprom command.
static State *
writeEepromState(void) {
static State state;
// TODO
state.next = idleState;
return &state;
}
// Handle "r" read eeprom command.
static State *
readEepromState(void) {
static State state;
// TODO
state.next = idleState;
return &state;
}
static void
configure(void) {
line_coding.dwDTERate = DATA_RATE;
line_coding.bCharFormat = CHAR_FORMAT;
line_coding.bParityType = PARITY_TYPE;
line_coding.bDataBits = DATA_BITS;
}
bool
USER_USB_CALLBACK_EVENT_HANDLER(USB_EVENT event, void *pdata, uint16_t size) {
switch ((int)event) {
case EVENT_TRANSFER:
break;
case EVENT_SOF:
break;
case EVENT_SUSPEND:
break;
case EVENT_RESUME:
break;
case EVENT_CONFIGURED:
CDCInitEP();
configure();
break;
case EVENT_SET_DESCRIPTOR:
break;
case EVENT_EP0_REQUEST:
USBCheckCDCRequest();
break;
case EVENT_BUS_ERROR:
break;
case EVENT_TRANSFER_TERMINATED:
break;
default:
break;
}
return true;
}
|