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93ac315e MPM |
1 | /* $Id: main.c,v 1.5 2010/06/09 23:13:28 simimeie Exp $ |
2 | * USB interface for ds1820 | |
3 | * This is the main file that glues it all together. | |
4 | * (C) Michael "Fox" Meier 2009 | |
5 | */ | |
6 | ||
7 | #include <avr/io.h> | |
8 | #include <avr/interrupt.h> | |
9 | #include <avr/wdt.h> | |
10 | #include <avr/power.h> | |
11 | #include <avr/sleep.h> | |
12 | #include <util/delay.h> | |
13 | #include "usbdrv/usbdrv.h" | |
14 | #include "ds1820.h" | |
15 | #include "time.h" | |
16 | ||
17 | uint8_t doprobescan = 1; | |
18 | uint8_t curprobe; | |
19 | uint8_t usbreadpos; | |
20 | uint32_t readpendingts; | |
21 | uint8_t readpending; | |
22 | ||
23 | /* This is needed to recover from a watchdog reset, as the watchdog | |
24 | * stays active after the reset. Without this we'll just do an | |
25 | * endless reset loop */ | |
26 | void get_mcusr(void) __attribute__((naked)) __attribute__((section(".init3"))); | |
27 | void get_mcusr(void) { | |
28 | MCUSR = 0; | |
29 | wdt_disable(); | |
30 | } | |
31 | ||
32 | /* This function is called when the driver receives a SETUP transaction from | |
33 | * the host which is not answered by the driver itself (in practice: class and | |
34 | * vendor requests). All control transfers start with a SETUP transaction where | |
35 | * the host communicates the parameters of the following (optional) data | |
36 | * transfer. The SETUP data is available in the 'data' parameter which can | |
37 | * (and should) be casted to 'usbRequest_t *' for a more user-friendly access | |
38 | * to parameters. [...] | |
39 | * in short: Set usbMsgPtr to your answer, and return number of bytes. | |
40 | * return USB_NO_MSG to supply the long answer packets with the usbFunctionRead. */ | |
41 | usbMsgLen_t usbFunctionSetup(uchar data[8]) | |
42 | { | |
43 | usbRequest_t *rq = (void *)data; | |
44 | static uchar replyBuf[8]; | |
45 | ||
46 | if (rq->bRequest == 0){ /* ECHO */ | |
47 | usbMsgPtr = replyBuf; | |
48 | replyBuf[0] = rq->wValue.bytes[0]; | |
49 | replyBuf[1] = rq->wValue.bytes[1]; | |
50 | return 2; | |
51 | } | |
52 | if (rq->bRequest == 1) { /* GET_STATUS_SHORT */ | |
53 | uint32_t curtime = gettime(); | |
54 | usbMsgPtr = replyBuf; | |
55 | replyBuf[0] = 0; /* Version high */ | |
56 | replyBuf[1] = 1; /* Version low */ | |
57 | replyBuf[2] = ((uint8_t *)&curtime)[0]; /* Time */ | |
58 | replyBuf[3] = ((uint8_t *)&curtime)[1]; | |
59 | replyBuf[4] = ((uint8_t *)&curtime)[2]; | |
60 | replyBuf[5] = ((uint8_t *)&curtime)[3]; | |
61 | replyBuf[6] = DS1820_MAXPROBES; /* max. number of probes */ | |
62 | replyBuf[7] = 0; /* UNUSED */ | |
63 | return 8; | |
64 | } | |
65 | if (rq->bRequest == 2) { /* RESCAN_BUS */ | |
66 | usbMsgPtr = replyBuf; | |
67 | if (doprobescan) { | |
68 | replyBuf[0] = 42; /* Scan already scheduled / in progress */ | |
69 | } else { | |
70 | replyBuf[0] = 23; /* OK, scan scheduled */ | |
71 | doprobescan = 1; | |
72 | } | |
73 | return 1; | |
74 | } | |
75 | if (rq->bRequest == 3) { /* GET_STATUS_LONG */ | |
76 | /* the answer to this query will list all probes on the bus | |
77 | * and thus can be very lengthy. We will handle that with usbFunctionRead */ | |
78 | usbreadpos = 0; | |
79 | return USB_NO_MSG; | |
80 | } | |
81 | if (rq->bRequest == 4) { /* RESET_HARD */ | |
82 | /* Reset, both the probe bus and ourselves. We reset ourselves through | |
83 | * the watchdog timer and just pull the 1wire bus low. */ | |
84 | ds1820killbus(); | |
85 | wdt_reset(); /* Make sure we get the full 2 seconds */ | |
86 | for (;;) { } | |
87 | } | |
88 | /* Unknown request. Ignore. */ | |
89 | return 0; | |
90 | } | |
91 | ||
92 | /* This function is called by the driver to ask the application for a control | |
93 | * transfer's payload data (control-in). It is called in chunks of up to 8 | |
94 | * bytes each. You should copy the data to the location given by 'data' and | |
95 | * return the actual number of bytes copied. If you return less than requested, | |
96 | * the control-in transfer is terminated. If you return 0xff, the driver aborts | |
97 | * the transfer with a STALL token. */ | |
98 | uchar usbFunctionRead(uchar *data, uchar len) { | |
99 | uint8_t i; | |
100 | for (i = 0; i < len; i++) { | |
101 | uint8_t j = usbreadpos + i; | |
102 | uint8_t probenum = j / 16; | |
103 | uint8_t probeoff = j % 16; | |
104 | if (probenum >= DS1820_MAXPROBES) { | |
105 | return (i - usbreadpos); /* the end - no more data */ | |
106 | } | |
107 | if (probeoff < 6) { | |
108 | data[i] = ds1820probes[probenum].serial[probeoff]; | |
109 | } else if (probeoff == 6) { | |
110 | data[i] = ds1820probes[probenum].family; | |
111 | } else if (probeoff == 7) { | |
112 | data[i] = ds1820probes[probenum].flags; | |
113 | } else if (probeoff == 8) { | |
114 | data[i] = ds1820probes[probenum].lasttemp[0]; | |
115 | } else if (probeoff == 9) { | |
116 | data[i] = ds1820probes[probenum].lasttemp[1]; | |
117 | } else if (probeoff < 14) { | |
118 | uint8_t * tp = (uint8_t *)&ds1820probes[probenum].lastts; | |
119 | data[i] = tp[probeoff - 10]; | |
120 | } else { | |
121 | data[i] = 0; /* Unused */ | |
122 | } | |
123 | } | |
124 | usbreadpos += len; | |
125 | return len; | |
126 | } | |
127 | ||
128 | int main(void) | |
129 | { | |
130 | /* Some powersaving: Disable unused stuff */ | |
131 | power_adc_disable(); | |
132 | power_usi_disable(); | |
133 | power_timer1_disable(); | |
134 | ||
135 | /* From the avr usb doku wiki: Call usbDeviceDisconnect(), wait several | |
136 | * 100 milliseconds and then call usbDeviceConnect(). This enforces | |
137 | * (re-)enumeration of the device. In theory, you don't need this, but | |
138 | * it prevents inconsistencies between host and device after hardware | |
139 | * or watchdog resets. */ | |
140 | usbDeviceDisconnect(); | |
141 | _delay_ms(500.0); | |
142 | usbDeviceConnect(); | |
143 | ||
144 | /* This function must be called before interrupts are enabled and the main | |
145 | * loop is entered. */ | |
146 | usbInit(); | |
147 | ||
148 | /* Reset if we don't return to the main loop within 2 seconds */ | |
149 | wdt_enable(WDTO_2S); | |
150 | ||
151 | /* Init the ds1820 code and bus */ | |
152 | ds1820init(); | |
153 | ||
154 | /* Init timer */ | |
155 | time_init(); | |
156 | ||
157 | /* Prepare sleep mode */ | |
158 | set_sleep_mode(SLEEP_MODE_IDLE); | |
159 | sleep_enable(); | |
160 | ||
161 | /* All set up, enable interrupts and go. */ | |
162 | sei(); | |
163 | ||
164 | while (1) { /* We should never exit, or should we? */ | |
165 | wdt_reset(); | |
166 | ||
167 | /* This function must be called at regular intervals from the main loop. | |
168 | * Maximum delay between calls is somewhat less than 50ms (USB timeout for | |
169 | * accepting a Setup message). Otherwise the device will not be recognized. | |
170 | * If other functions are called from the USB code, they will be called from | |
171 | * usbPoll(). */ | |
172 | usbPoll(); | |
173 | ||
174 | if ((readpending == 0) && (doprobescan)) { | |
175 | ds1820scan(); | |
176 | doprobescan = 0; | |
177 | curprobe = 0; | |
178 | } else { | |
179 | if (readpending == 0) { | |
180 | /* Select next probe to query */ | |
181 | if ((ds1820probes[curprobe].flags & DS1820FLAG_SLOTINUSE) == DS1820FLAG_SLOTINUSE) { | |
182 | ds1820queryprobe(curprobe); | |
183 | } | |
184 | readpending = 1; | |
185 | readpendingts = gettime(); | |
186 | } else { | |
187 | if ((gettime() - readpendingts) > 60) { /* >1 second passed, data should be ready */ | |
188 | if ((ds1820probes[curprobe].flags & DS1820FLAG_SLOTINUSE) == DS1820FLAG_SLOTINUSE) { /* Is that probe even there? */ | |
189 | if (ds1820updateprobe(curprobe)) { /* Successful, send updated data */ | |
190 | if (usbInterruptIsReady()) { /* Last message has been sent, so send new data */ | |
191 | uint8_t whattosend[8]; | |
192 | uint8_t i; | |
193 | for (i = 0; i < 6; i++) { | |
194 | whattosend[i] = ds1820probes[curprobe].serial[i]; | |
195 | } | |
196 | whattosend[6] = ds1820probes[curprobe].lasttemp[0]; | |
197 | whattosend[7] = ds1820probes[curprobe].lasttemp[1]; | |
198 | /* This function sets the message which will be sent during the next interrupt | |
199 | * IN transfer. The message is copied to an internal buffer and must not exceed | |
200 | * a length of 8 bytes. The message may be 0 bytes long just to indicate the | |
201 | * interrupt status to the host. | |
202 | * If you need to transfer more bytes, use a control read after the interrupt. */ | |
203 | /* void usbSetInterrupt(uchar *data, uchar len);*/ | |
204 | usbSetInterrupt(whattosend, 8); | |
205 | } | |
206 | } | |
207 | } | |
208 | curprobe++; | |
209 | if (curprobe >= DS1820_MAXPROBES) { curprobe = 0; } | |
210 | readpending = 0; | |
211 | } | |
212 | } | |
213 | } | |
214 | ||
215 | /* Go to sleep now */ | |
216 | sleep_cpu(); | |
217 | } | |
218 | ||
219 | /* Never reached */ | |
220 | return 0; | |
221 | } |