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Diffstat (limited to 'firmware/drivers/synaptics-mep.c')
-rw-r--r-- | firmware/drivers/synaptics-mep.c | 482 |
1 files changed, 482 insertions, 0 deletions
diff --git a/firmware/drivers/synaptics-mep.c b/firmware/drivers/synaptics-mep.c new file mode 100644 index 0000000000..44b186034f --- /dev/null +++ b/firmware/drivers/synaptics-mep.c | |||
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1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2008 by Mark Arigo | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | |||
22 | #include <stdlib.h> | ||
23 | #include "config.h" | ||
24 | #include "cpu.h" | ||
25 | #include "system.h" | ||
26 | #include "kernel.h" | ||
27 | #include "system.h" | ||
28 | |||
29 | #define LOGF_ENABLE | ||
30 | #include "logf.h" | ||
31 | |||
32 | /* Driver for the Synaptics Touchpad based on the "Synaptics Modular Embedded | ||
33 | Protocol: 3-Wire Interface Specification" documentation */ | ||
34 | |||
35 | #define ACK (GPIOD_INPUT_VAL & 0x1) | ||
36 | #define ACK_HI GPIOD_OUTPUT_VAL |= 0x1 | ||
37 | #define ACK_LO GPIOD_OUTPUT_VAL &= ~0x1 | ||
38 | |||
39 | #define CLK ((GPIOD_INPUT_VAL & 0x2) >> 1) | ||
40 | #define CLK_HI GPIOD_OUTPUT_VAL |= 0x2 | ||
41 | #define CLK_LO GPIOD_OUTPUT_VAL &= ~0x2 | ||
42 | |||
43 | #define DATA ((GPIOD_INPUT_VAL & 0x4) >> 2) | ||
44 | #define DATA_HI GPIOD_OUTPUT_EN |= 0x4; GPIOD_OUTPUT_VAL |= 0x4 | ||
45 | #define DATA_LO GPIOD_OUTPUT_EN |= 0x4; GPIOD_OUTPUT_VAL &= ~0x4 | ||
46 | #define DATA_CL GPIOD_OUTPUT_EN &= ~0x4 | ||
47 | |||
48 | #define LO 0 | ||
49 | #define HI 1 | ||
50 | |||
51 | #define READ_RETRY 8 | ||
52 | #define READ_ERROR -1 | ||
53 | |||
54 | #define MEP_HELLO_HEADER 0x19 | ||
55 | #define MEP_HELLO_ID 0x1 | ||
56 | |||
57 | #define MEP_READ 0x1 | ||
58 | #define MEP_WRITE 0x3 | ||
59 | |||
60 | static int syn_wait_clk_change(unsigned int val) | ||
61 | { | ||
62 | int i; | ||
63 | |||
64 | for (i = 0; i < 10000; i++) | ||
65 | { | ||
66 | if (CLK == val) | ||
67 | return 1; | ||
68 | } | ||
69 | |||
70 | return 0; | ||
71 | } | ||
72 | |||
73 | static inline int syn_get_data(void) | ||
74 | { | ||
75 | DATA_CL; | ||
76 | return DATA; | ||
77 | } | ||
78 | |||
79 | static void syn_wait_guest_flush(void) | ||
80 | { | ||
81 | /* Flush receiving (flushee) state: | ||
82 | handshake until DATA goes high during P3 stage */ | ||
83 | if (CLK == LO) | ||
84 | { | ||
85 | ACK_HI; /* P1 -> P2 */ | ||
86 | syn_wait_clk_change(HI); /* P2 -> P3 */ | ||
87 | } | ||
88 | |||
89 | while (syn_get_data() == LO) | ||
90 | { | ||
91 | ACK_HI; /* P3 -> P0 */ | ||
92 | syn_wait_clk_change(LO); /* P0 -> P1 */ | ||
93 | ACK_LO; /* P1 -> P2 */ | ||
94 | syn_wait_clk_change(HI); /* P2 -> P3 */ | ||
95 | } | ||
96 | |||
97 | /* Continue handshaking until back to P0 */ | ||
98 | ACK_HI; /* P3 -> P0 */ | ||
99 | } | ||
100 | |||
101 | static void syn_flush(void) | ||
102 | { | ||
103 | int i; | ||
104 | |||
105 | logf("syn_flush..."); | ||
106 | |||
107 | /* Flusher holds DATA low for at least 36 handshake cycles */ | ||
108 | DATA_LO; | ||
109 | |||
110 | for (i = 0; i < 36; i++) | ||
111 | { | ||
112 | syn_wait_clk_change(LO); /* P0 -> P1 */ | ||
113 | ACK_LO; /* P1 -> P2 */ | ||
114 | syn_wait_clk_change(HI); /* P2 -> P3 */ | ||
115 | ACK_HI; /* P3 -> P0 */ | ||
116 | } | ||
117 | |||
118 | /* Raise DATA in P1 stage */ | ||
119 | syn_wait_clk_change(LO); /* P0 -> P1 */ | ||
120 | DATA_HI; | ||
121 | |||
122 | /* After a flush, the flushing device enters a flush-receiving (flushee) | ||
123 | state */ | ||
124 | syn_wait_guest_flush(); | ||
125 | } | ||
126 | |||
127 | static int syn_send_data(int *data, int len) | ||
128 | { | ||
129 | int i, bit; | ||
130 | int parity = 0; | ||
131 | |||
132 | logf("syn_send_data..."); | ||
133 | |||
134 | /* 1. Lower DATA line to issue a request-to-send to guest */ | ||
135 | DATA_LO; | ||
136 | |||
137 | /* 2. Wait for guest to lower CLK */ | ||
138 | syn_wait_clk_change(LO); | ||
139 | |||
140 | /* 3. Lower ACK (with DATA still low) */ | ||
141 | ACK_LO; | ||
142 | |||
143 | /* 4. Wait for guest to raise CLK */ | ||
144 | syn_wait_clk_change(HI); | ||
145 | |||
146 | /* 5. Send data */ | ||
147 | for (i = 0; i < len; i++) | ||
148 | { | ||
149 | logf(" sending byte: %d", data[i]); | ||
150 | |||
151 | bit = 0; | ||
152 | while (bit < 8) | ||
153 | { | ||
154 | /* 5a. Drive data low if bit is 0, or high if bit is 1 */ | ||
155 | if (data[i] & (1 << bit)) | ||
156 | { | ||
157 | DATA_HI; | ||
158 | parity++; | ||
159 | } | ||
160 | else | ||
161 | { | ||
162 | DATA_LO; | ||
163 | } | ||
164 | bit++; | ||
165 | |||
166 | /* 5b. Invert ACK to indicate that the data bit is ready */ | ||
167 | ACK_HI; | ||
168 | |||
169 | /* 5c. Wait for guest to invert CLK */ | ||
170 | syn_wait_clk_change(LO); | ||
171 | |||
172 | /* Repeat for next bit */ | ||
173 | if (data[i] & (1 << bit)) | ||
174 | { | ||
175 | DATA_HI; | ||
176 | parity++; | ||
177 | } | ||
178 | else | ||
179 | { | ||
180 | DATA_LO; | ||
181 | } | ||
182 | bit++; | ||
183 | |||
184 | ACK_LO; | ||
185 | |||
186 | syn_wait_clk_change(HI); | ||
187 | } | ||
188 | } | ||
189 | |||
190 | /* 7. Transmission termination sequence: */ | ||
191 | /* 7a. Host may put parity bit on DATA. Hosts that do not generate | ||
192 | parity should set DATA high. Parity is 1 if there's an odd | ||
193 | number of '1' bits, or 0 if there's an even number of '1' bits. */ | ||
194 | parity = parity % 2; | ||
195 | if (parity) | ||
196 | { | ||
197 | DATA_HI; | ||
198 | } | ||
199 | else | ||
200 | { | ||
201 | DATA_LO; | ||
202 | } | ||
203 | logf(" send parity = %d", parity); | ||
204 | |||
205 | /* 7b. Raise ACK to indicate that the optional parity bit is ready */ | ||
206 | ACK_HI; | ||
207 | |||
208 | /* 7c. Guest lowers CLK */ | ||
209 | syn_wait_clk_change(LO); | ||
210 | |||
211 | /* 7d. Pull DATA high (if parity bit was 0) */ | ||
212 | DATA_HI; | ||
213 | |||
214 | /* 7e. Lower ACK to indicate that the stop bit is ready */ | ||
215 | ACK_LO; | ||
216 | |||
217 | /* 7f. Guest raises CLK */ | ||
218 | syn_wait_clk_change(HI); | ||
219 | |||
220 | /* 7g. If DATA is low, guest is flushing this transfer. Host should | ||
221 | enter the flushee state. */ | ||
222 | if (syn_get_data() == LO) | ||
223 | { | ||
224 | logf(" module flushing"); | ||
225 | |||
226 | syn_wait_guest_flush(); | ||
227 | return -1; | ||
228 | } | ||
229 | |||
230 | /* 7h. Host raises ACK and the link enters the idle state */ | ||
231 | ACK_HI; | ||
232 | |||
233 | return len; | ||
234 | } | ||
235 | |||
236 | static int syn_read_data(int *data, int data_len) | ||
237 | { | ||
238 | int i, len, bit, parity, tmp; | ||
239 | int *data_ptr; | ||
240 | |||
241 | logf("syn_read_data..."); | ||
242 | |||
243 | /* 1. Guest drives CLK low */ | ||
244 | if (CLK != LO) | ||
245 | return 0; | ||
246 | |||
247 | /* 1a. If the host is willing to receive a packet it lowers ACK */ | ||
248 | ACK_LO; | ||
249 | |||
250 | /* 2. Guest may issue a request-to-send by lowering DATA. If the | ||
251 | guest decides not to transmit a packet, it may abort the | ||
252 | transmission by not lowering DATA. */ | ||
253 | |||
254 | /* 3. The guest raises CLK */ | ||
255 | syn_wait_clk_change(HI); | ||
256 | |||
257 | /* 4. If the guest is still driving DATA low, the transfer is commited | ||
258 | to occur. Otherwise, the transfer is aborted. In either case, | ||
259 | the host raises ACK. */ | ||
260 | if (syn_get_data() == HI) | ||
261 | { | ||
262 | logf(" read abort"); | ||
263 | |||
264 | ACK_HI; | ||
265 | return READ_ERROR; | ||
266 | } | ||
267 | else | ||
268 | { | ||
269 | ACK_HI; | ||
270 | } | ||
271 | |||
272 | /* 5. Read the incoming data packet */ | ||
273 | i = 0; | ||
274 | len = 0; | ||
275 | parity = 0; | ||
276 | while (i <= len) | ||
277 | { | ||
278 | bit = 0; | ||
279 | |||
280 | if (i < data_len) | ||
281 | data_ptr = &data[i]; | ||
282 | else | ||
283 | data_ptr = &tmp; | ||
284 | |||
285 | *data_ptr = 0; | ||
286 | while (bit < 8) | ||
287 | { | ||
288 | /* 5b. Guset inverts CLK to indicate that data is ready */ | ||
289 | syn_wait_clk_change(LO); | ||
290 | |||
291 | /* 5d. Read the data bit from DATA */ | ||
292 | if (syn_get_data() == HI) | ||
293 | { | ||
294 | *data_ptr |= (1 << bit); | ||
295 | parity++; | ||
296 | } | ||
297 | bit++; | ||
298 | |||
299 | /* 5e. Invert ACK to indicate that data has been read */ | ||
300 | ACK_LO; | ||
301 | |||
302 | /* Repeat for next bit */ | ||
303 | syn_wait_clk_change(HI); | ||
304 | |||
305 | if (syn_get_data() == HI) | ||
306 | { | ||
307 | *data_ptr |= (1 << bit); | ||
308 | parity++; | ||
309 | } | ||
310 | bit++; | ||
311 | |||
312 | ACK_HI; | ||
313 | } | ||
314 | |||
315 | /* First byte is the packet header */ | ||
316 | if (i == 0) | ||
317 | { | ||
318 | /* Format control (bit 3) should be 1 */ | ||
319 | if (*data_ptr & 0x8) | ||
320 | { | ||
321 | /* Packet length is bits 0:2 */ | ||
322 | len = *data_ptr & 0x7; | ||
323 | logf(" packet length = %d", len); | ||
324 | } | ||
325 | else | ||
326 | { | ||
327 | logf(" invalid format ctrl bit"); | ||
328 | return READ_ERROR; | ||
329 | } | ||
330 | } | ||
331 | |||
332 | i++; | ||
333 | } | ||
334 | |||
335 | /* 7. Transmission termination cycle */ | ||
336 | /* 7a. The guest generates a parity bit on DATA */ | ||
337 | /* 7b. The host waits for guest to lower CLK */ | ||
338 | syn_wait_clk_change(LO); | ||
339 | |||
340 | /* 7c. The host verifies the parity bit is correct */ | ||
341 | parity = parity % 2; | ||
342 | logf(" parity check: %d / %d", syn_get_data(), parity); | ||
343 | |||
344 | /* TODO: parity error handling */ | ||
345 | |||
346 | /* 7d. The host lowers ACK */ | ||
347 | ACK_LO; | ||
348 | |||
349 | /* 7e. The host waits for the guest to raise CLK indicating | ||
350 | that the stop bit is ready */ | ||
351 | syn_wait_clk_change(HI); | ||
352 | |||
353 | /* 7f. The host reads DATA and verifies that it is 1 */ | ||
354 | if (syn_get_data() == LO) | ||
355 | { | ||
356 | logf(" framing error"); | ||
357 | |||
358 | ACK_HI; | ||
359 | return READ_ERROR; | ||
360 | } | ||
361 | |||
362 | ACK_HI; | ||
363 | |||
364 | return len; | ||
365 | } | ||
366 | |||
367 | int syn_read_device(int *data, int len) | ||
368 | { | ||
369 | int i; | ||
370 | int ret = READ_ERROR; | ||
371 | |||
372 | for (i = 0; i < READ_RETRY; i++) | ||
373 | { | ||
374 | if (syn_wait_clk_change(LO)) | ||
375 | { | ||
376 | /* module is sending data */ | ||
377 | ret = syn_read_data(data, len); | ||
378 | if (ret != READ_ERROR) | ||
379 | return ret; | ||
380 | |||
381 | syn_flush(); | ||
382 | } | ||
383 | else | ||
384 | { | ||
385 | /* module is idle */ | ||
386 | return 0; | ||
387 | } | ||
388 | } | ||
389 | |||
390 | return ret; | ||
391 | } | ||
392 | |||
393 | static int syn_reset(void) | ||
394 | { | ||
395 | int val, id; | ||
396 | int data[2]; | ||
397 | |||
398 | logf("syn_reset..."); | ||
399 | |||
400 | /* reset module 0 */ | ||
401 | val = (0 << 4) | (1 << 3) | 0; | ||
402 | syn_send_data(&val, 1); | ||
403 | |||
404 | val = syn_read_device(data, 2); | ||
405 | if (val == 1) | ||
406 | { | ||
407 | val = data[0] & 0xff; /* packet header */ | ||
408 | id = (data[1] >> 4) & 0xf; /* packet id */ | ||
409 | if ((val == MEP_HELLO_HEADER) && (id == MEP_HELLO_ID)) | ||
410 | { | ||
411 | logf(" module 0 reset"); | ||
412 | return 1; | ||
413 | } | ||
414 | } | ||
415 | |||
416 | logf(" reset failed"); | ||
417 | return 0; | ||
418 | } | ||
419 | |||
420 | int syn_init(void) | ||
421 | { | ||
422 | syn_flush(); | ||
423 | return syn_reset(); | ||
424 | } | ||
425 | |||
426 | #ifdef ROCKBOX_HAS_LOGF | ||
427 | void syn_info(void) | ||
428 | { | ||
429 | int i, val; | ||
430 | int data[8]; | ||
431 | |||
432 | logf("syn_info..."); | ||
433 | |||
434 | /* module base info */ | ||
435 | logf("module base info:"); | ||
436 | data[0] = MEP_READ; | ||
437 | data[1] = 0x80; | ||
438 | syn_send_data(data, 2); | ||
439 | val = syn_read_device(data, 8); | ||
440 | if (val > 0) | ||
441 | { | ||
442 | for (i = 0; i < 8; i++) | ||
443 | logf(" data[%d] = 0x%02x", i, data[i]); | ||
444 | } | ||
445 | |||
446 | /* module product info */ | ||
447 | logf("module product info:"); | ||
448 | data[0] = MEP_READ; | ||
449 | data[1] = 0x81; | ||
450 | syn_send_data(data, 2); | ||
451 | val = syn_read_device(data, 8); | ||
452 | if (val > 0) | ||
453 | { | ||
454 | for (i = 0; i < 8; i++) | ||
455 | logf(" data[%d] = 0x%02x", i, data[i]); | ||
456 | } | ||
457 | |||
458 | /* module serialization */ | ||
459 | logf("module serialization:"); | ||
460 | data[0] = MEP_READ; | ||
461 | data[1] = 0x82; | ||
462 | syn_send_data(data, 2); | ||
463 | val = syn_read_device(data, 8); | ||
464 | if (val > 0) | ||
465 | { | ||
466 | for (i = 0; i < 8; i++) | ||
467 | logf(" data[%d] = 0x%02x", i, data[i]); | ||
468 | } | ||
469 | |||
470 | /* 1-D sensor info */ | ||
471 | logf("1-d sensor info:"); | ||
472 | data[0] = MEP_READ; | ||
473 | data[1] = 0x80 + 0x20; | ||
474 | syn_send_data(data, 2); | ||
475 | val = syn_read_device(data, 8); | ||
476 | if (val > 0) | ||
477 | { | ||
478 | for (i = 0; i < 8; i++) | ||
479 | logf(" data[%d] = 0x%02x", i, data[i]); | ||
480 | } | ||
481 | } | ||
482 | #endif | ||