1 /*
2 * 1-wire busmaster driver for DS1WM and ASICs with embedded DS1WMs
3 * such as HP iPAQs (including h5xxx, h2200, and devices with ASIC3
4 * like hx4700).
5 *
6 * Copyright (c) 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
7 * Copyright (c) 2004-2007, Matt Reimer <mreimer@vpop.net>
8 *
9 * Use consistent with the GNU GPL is permitted,
10 * provided that this copyright notice is
11 * preserved in its entirety in all copies and derived works.
12 */
13
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/pm.h>
18 #include <linux/platform_device.h>
19 #include <linux/err.h>
20 #include <linux/delay.h>
21 #include <linux/mfd/core.h>
22 #include <linux/mfd/ds1wm.h>
23 #include <linux/slab.h>
24
25 #include <asm/io.h>
26
27 #include "../w1.h"
28 #include "../w1_int.h"
29
30
31 #define DS1WM_CMD 0x00 /* R/W 4 bits command */
32 #define DS1WM_DATA 0x01 /* R/W 8 bits, transmit/receive buffer */
33 #define DS1WM_INT 0x02 /* R/W interrupt status */
34 #define DS1WM_INT_EN 0x03 /* R/W interrupt enable */
35 #define DS1WM_CLKDIV 0x04 /* R/W 5 bits of divisor and pre-scale */
36 #define DS1WM_CNTRL 0x05 /* R/W master control register (not used yet) */
37
38 #define DS1WM_CMD_1W_RESET (1 << 0) /* force reset on 1-wire bus */
39 #define DS1WM_CMD_SRA (1 << 1) /* enable Search ROM accelerator mode */
40 #define DS1WM_CMD_DQ_OUTPUT (1 << 2) /* write only - forces bus low */
41 #define DS1WM_CMD_DQ_INPUT (1 << 3) /* read only - reflects state of bus */
42 #define DS1WM_CMD_RST (1 << 5) /* software reset */
43 #define DS1WM_CMD_OD (1 << 7) /* overdrive */
44
45 #define DS1WM_INT_PD (1 << 0) /* presence detect */
46 #define DS1WM_INT_PDR (1 << 1) /* presence detect result */
47 #define DS1WM_INT_TBE (1 << 2) /* tx buffer empty */
48 #define DS1WM_INT_TSRE (1 << 3) /* tx shift register empty */
49 #define DS1WM_INT_RBF (1 << 4) /* rx buffer full */
50 #define DS1WM_INT_RSRF (1 << 5) /* rx shift register full */
51
52 #define DS1WM_INTEN_EPD (1 << 0) /* enable presence detect int */
53 #define DS1WM_INTEN_IAS (1 << 1) /* INTR active state */
54 #define DS1WM_INTEN_ETBE (1 << 2) /* enable tx buffer empty int */
55 #define DS1WM_INTEN_ETMT (1 << 3) /* enable tx shift register empty int */
56 #define DS1WM_INTEN_ERBF (1 << 4) /* enable rx buffer full int */
57 #define DS1WM_INTEN_ERSRF (1 << 5) /* enable rx shift register full int */
58 #define DS1WM_INTEN_DQO (1 << 6) /* enable direct bus driving ops */
59
60 #define DS1WM_INTEN_NOT_IAS (~DS1WM_INTEN_IAS) /* all but INTR active state */
61
62 #define DS1WM_TIMEOUT (HZ * 5)
63
64 static struct {
65 unsigned long freq;
66 unsigned long divisor;
67 } freq[] = {
68 { 1000000, 0x80 },
69 { 2000000, 0x84 },
70 { 3000000, 0x81 },
71 { 4000000, 0x88 },
72 { 5000000, 0x82 },
73 { 6000000, 0x85 },
74 { 7000000, 0x83 },
75 { 8000000, 0x8c },
76 { 10000000, 0x86 },
77 { 12000000, 0x89 },
78 { 14000000, 0x87 },
79 { 16000000, 0x90 },
80 { 20000000, 0x8a },
81 { 24000000, 0x8d },
82 { 28000000, 0x8b },
83 { 32000000, 0x94 },
84 { 40000000, 0x8e },
85 { 48000000, 0x91 },
86 { 56000000, 0x8f },
87 { 64000000, 0x98 },
88 { 80000000, 0x92 },
89 { 96000000, 0x95 },
90 { 112000000, 0x93 },
91 { 128000000, 0x9c },
92 /* you can continue this table, consult the OPERATION - CLOCK DIVISOR
93 section of the ds1wm spec sheet. */
94 };
95
96 struct ds1wm_data {
97 void __iomem *map;
98 int bus_shift; /* # of shifts to calc register offsets */
99 struct platform_device *pdev;
100 const struct mfd_cell *cell;
101 int irq;
102 int slave_present;
103 void *reset_complete;
104 void *read_complete;
105 void *write_complete;
106 int read_error;
107 /* last byte received */
108 u8 read_byte;
109 /* byte to write that makes all intr disabled, */
110 /* considering active_state (IAS) (optimization) */
111 u8 int_en_reg_none;
112 unsigned int reset_recover_delay; /* see ds1wm.h */
113 };
114
ds1wm_write_register(struct ds1wm_data * ds1wm_data,u32 reg,u8 val)115 static inline void ds1wm_write_register(struct ds1wm_data *ds1wm_data, u32 reg,
116 u8 val)
117 {
118 __raw_writeb(val, ds1wm_data->map + (reg << ds1wm_data->bus_shift));
119 }
120
ds1wm_read_register(struct ds1wm_data * ds1wm_data,u32 reg)121 static inline u8 ds1wm_read_register(struct ds1wm_data *ds1wm_data, u32 reg)
122 {
123 return __raw_readb(ds1wm_data->map + (reg << ds1wm_data->bus_shift));
124 }
125
126
ds1wm_isr(int isr,void * data)127 static irqreturn_t ds1wm_isr(int isr, void *data)
128 {
129 struct ds1wm_data *ds1wm_data = data;
130 u8 intr;
131 u8 inten = ds1wm_read_register(ds1wm_data, DS1WM_INT_EN);
132 /* if no bits are set in int enable register (except the IAS)
133 than go no further, reading the regs below has side effects */
134 if (!(inten & DS1WM_INTEN_NOT_IAS))
135 return IRQ_NONE;
136
137 ds1wm_write_register(ds1wm_data,
138 DS1WM_INT_EN, ds1wm_data->int_en_reg_none);
139
140 /* this read action clears the INTR and certain flags in ds1wm */
141 intr = ds1wm_read_register(ds1wm_data, DS1WM_INT);
142
143 ds1wm_data->slave_present = (intr & DS1WM_INT_PDR) ? 0 : 1;
144
145 if ((intr & DS1WM_INT_TSRE) && ds1wm_data->write_complete) {
146 inten &= ~DS1WM_INTEN_ETMT;
147 complete(ds1wm_data->write_complete);
148 }
149 if (intr & DS1WM_INT_RBF) {
150 /* this read clears the RBF flag */
151 ds1wm_data->read_byte = ds1wm_read_register(ds1wm_data,
152 DS1WM_DATA);
153 inten &= ~DS1WM_INTEN_ERBF;
154 if (ds1wm_data->read_complete)
155 complete(ds1wm_data->read_complete);
156 }
157 if ((intr & DS1WM_INT_PD) && ds1wm_data->reset_complete) {
158 inten &= ~DS1WM_INTEN_EPD;
159 complete(ds1wm_data->reset_complete);
160 }
161
162 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, inten);
163 return IRQ_HANDLED;
164 }
165
ds1wm_reset(struct ds1wm_data * ds1wm_data)166 static int ds1wm_reset(struct ds1wm_data *ds1wm_data)
167 {
168 unsigned long timeleft;
169 DECLARE_COMPLETION_ONSTACK(reset_done);
170
171 ds1wm_data->reset_complete = &reset_done;
172
173 /* enable Presence detect only */
174 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, DS1WM_INTEN_EPD |
175 ds1wm_data->int_en_reg_none);
176
177 ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_1W_RESET);
178
179 timeleft = wait_for_completion_timeout(&reset_done, DS1WM_TIMEOUT);
180 ds1wm_data->reset_complete = NULL;
181 if (!timeleft) {
182 dev_err(&ds1wm_data->pdev->dev, "reset failed, timed out\n");
183 return 1;
184 }
185
186 if (!ds1wm_data->slave_present) {
187 dev_dbg(&ds1wm_data->pdev->dev, "reset: no devices found\n");
188 return 1;
189 }
190
191 if (ds1wm_data->reset_recover_delay)
192 msleep(ds1wm_data->reset_recover_delay);
193
194 return 0;
195 }
196
ds1wm_write(struct ds1wm_data * ds1wm_data,u8 data)197 static int ds1wm_write(struct ds1wm_data *ds1wm_data, u8 data)
198 {
199 unsigned long timeleft;
200 DECLARE_COMPLETION_ONSTACK(write_done);
201 ds1wm_data->write_complete = &write_done;
202
203 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN,
204 ds1wm_data->int_en_reg_none | DS1WM_INTEN_ETMT);
205
206 ds1wm_write_register(ds1wm_data, DS1WM_DATA, data);
207
208 timeleft = wait_for_completion_timeout(&write_done, DS1WM_TIMEOUT);
209
210 ds1wm_data->write_complete = NULL;
211 if (!timeleft) {
212 dev_err(&ds1wm_data->pdev->dev, "write failed, timed out\n");
213 return -ETIMEDOUT;
214 }
215
216 return 0;
217 }
218
ds1wm_read(struct ds1wm_data * ds1wm_data,unsigned char write_data)219 static u8 ds1wm_read(struct ds1wm_data *ds1wm_data, unsigned char write_data)
220 {
221 unsigned long timeleft;
222 u8 intEnable = DS1WM_INTEN_ERBF | ds1wm_data->int_en_reg_none;
223 DECLARE_COMPLETION_ONSTACK(read_done);
224
225 ds1wm_read_register(ds1wm_data, DS1WM_DATA);
226
227 ds1wm_data->read_complete = &read_done;
228 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, intEnable);
229
230 ds1wm_write_register(ds1wm_data, DS1WM_DATA, write_data);
231 timeleft = wait_for_completion_timeout(&read_done, DS1WM_TIMEOUT);
232
233 ds1wm_data->read_complete = NULL;
234 if (!timeleft) {
235 dev_err(&ds1wm_data->pdev->dev, "read failed, timed out\n");
236 ds1wm_data->read_error = -ETIMEDOUT;
237 return 0xFF;
238 }
239 ds1wm_data->read_error = 0;
240 return ds1wm_data->read_byte;
241 }
242
ds1wm_find_divisor(int gclk)243 static int ds1wm_find_divisor(int gclk)
244 {
245 int i;
246
247 for (i = ARRAY_SIZE(freq)-1; i >= 0; --i)
248 if (gclk >= freq[i].freq)
249 return freq[i].divisor;
250
251 return 0;
252 }
253
ds1wm_up(struct ds1wm_data * ds1wm_data)254 static void ds1wm_up(struct ds1wm_data *ds1wm_data)
255 {
256 int divisor;
257 struct ds1wm_driver_data *plat = ds1wm_data->pdev->dev.platform_data;
258
259 if (ds1wm_data->cell->enable)
260 ds1wm_data->cell->enable(ds1wm_data->pdev);
261
262 divisor = ds1wm_find_divisor(plat->clock_rate);
263 dev_dbg(&ds1wm_data->pdev->dev,
264 "found divisor 0x%x for clock %d\n", divisor, plat->clock_rate);
265 if (divisor == 0) {
266 dev_err(&ds1wm_data->pdev->dev,
267 "no suitable divisor for %dHz clock\n",
268 plat->clock_rate);
269 return;
270 }
271 ds1wm_write_register(ds1wm_data, DS1WM_CLKDIV, divisor);
272
273 /* Let the w1 clock stabilize. */
274 msleep(1);
275
276 ds1wm_reset(ds1wm_data);
277 }
278
ds1wm_down(struct ds1wm_data * ds1wm_data)279 static void ds1wm_down(struct ds1wm_data *ds1wm_data)
280 {
281 ds1wm_reset(ds1wm_data);
282
283 /* Disable interrupts. */
284 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN,
285 ds1wm_data->int_en_reg_none);
286
287 if (ds1wm_data->cell->disable)
288 ds1wm_data->cell->disable(ds1wm_data->pdev);
289 }
290
291 /* --------------------------------------------------------------------- */
292 /* w1 methods */
293
ds1wm_read_byte(void * data)294 static u8 ds1wm_read_byte(void *data)
295 {
296 struct ds1wm_data *ds1wm_data = data;
297
298 return ds1wm_read(ds1wm_data, 0xff);
299 }
300
ds1wm_write_byte(void * data,u8 byte)301 static void ds1wm_write_byte(void *data, u8 byte)
302 {
303 struct ds1wm_data *ds1wm_data = data;
304
305 ds1wm_write(ds1wm_data, byte);
306 }
307
ds1wm_reset_bus(void * data)308 static u8 ds1wm_reset_bus(void *data)
309 {
310 struct ds1wm_data *ds1wm_data = data;
311
312 ds1wm_reset(ds1wm_data);
313
314 return 0;
315 }
316
ds1wm_search(void * data,struct w1_master * master_dev,u8 search_type,w1_slave_found_callback slave_found)317 static void ds1wm_search(void *data, struct w1_master *master_dev,
318 u8 search_type, w1_slave_found_callback slave_found)
319 {
320 struct ds1wm_data *ds1wm_data = data;
321 int i;
322 int ms_discrep_bit = -1;
323 u64 r = 0; /* holds the progress of the search */
324 u64 r_prime, d;
325 unsigned slaves_found = 0;
326 unsigned int pass = 0;
327
328 dev_dbg(&ds1wm_data->pdev->dev, "search begin\n");
329 while (true) {
330 ++pass;
331 if (pass > 100) {
332 dev_dbg(&ds1wm_data->pdev->dev,
333 "too many attempts (100), search aborted\n");
334 return;
335 }
336
337 if (ds1wm_reset(ds1wm_data)) {
338 dev_dbg(&ds1wm_data->pdev->dev,
339 "pass: %d reset error (or no slaves)\n", pass);
340 break;
341 }
342
343 dev_dbg(&ds1wm_data->pdev->dev,
344 "pass: %d r : %0#18llx writing SEARCH_ROM\n", pass, r);
345 ds1wm_write(ds1wm_data, search_type);
346 dev_dbg(&ds1wm_data->pdev->dev,
347 "pass: %d entering ASM\n", pass);
348 ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_SRA);
349 dev_dbg(&ds1wm_data->pdev->dev,
350 "pass: %d begining nibble loop\n", pass);
351
352 r_prime = 0;
353 d = 0;
354 /* we work one nibble at a time */
355 /* each nibble is interleaved to form a byte */
356 for (i = 0; i < 16; i++) {
357
358 unsigned char resp, _r, _r_prime, _d;
359
360 _r = (r >> (4*i)) & 0xf;
361 _r = ((_r & 0x1) << 1) |
362 ((_r & 0x2) << 2) |
363 ((_r & 0x4) << 3) |
364 ((_r & 0x8) << 4);
365
366 /* writes _r, then reads back: */
367 resp = ds1wm_read(ds1wm_data, _r);
368
369 if (ds1wm_data->read_error) {
370 dev_err(&ds1wm_data->pdev->dev,
371 "pass: %d nibble: %d read error\n", pass, i);
372 break;
373 }
374
375 _r_prime = ((resp & 0x02) >> 1) |
376 ((resp & 0x08) >> 2) |
377 ((resp & 0x20) >> 3) |
378 ((resp & 0x80) >> 4);
379
380 _d = ((resp & 0x01) >> 0) |
381 ((resp & 0x04) >> 1) |
382 ((resp & 0x10) >> 2) |
383 ((resp & 0x40) >> 3);
384
385 r_prime |= (unsigned long long) _r_prime << (i * 4);
386 d |= (unsigned long long) _d << (i * 4);
387
388 }
389 if (ds1wm_data->read_error) {
390 dev_err(&ds1wm_data->pdev->dev,
391 "pass: %d read error, retrying\n", pass);
392 break;
393 }
394 dev_dbg(&ds1wm_data->pdev->dev,
395 "pass: %d r\': %0#18llx d:%0#18llx\n",
396 pass, r_prime, d);
397 dev_dbg(&ds1wm_data->pdev->dev,
398 "pass: %d nibble loop complete, exiting ASM\n", pass);
399 ds1wm_write_register(ds1wm_data, DS1WM_CMD, ~DS1WM_CMD_SRA);
400 dev_dbg(&ds1wm_data->pdev->dev,
401 "pass: %d resetting bus\n", pass);
402 ds1wm_reset(ds1wm_data);
403 if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) {
404 dev_err(&ds1wm_data->pdev->dev,
405 "pass: %d bus error, retrying\n", pass);
406 continue; /* start over */
407 }
408
409
410 dev_dbg(&ds1wm_data->pdev->dev,
411 "pass: %d found %0#18llx\n", pass, r_prime);
412 slave_found(master_dev, r_prime);
413 ++slaves_found;
414 dev_dbg(&ds1wm_data->pdev->dev,
415 "pass: %d complete, preparing next pass\n", pass);
416
417 /* any discrepency found which we already choose the
418 '1' branch is now is now irrelevant we reveal the
419 next branch with this: */
420 d &= ~r;
421 /* find last bit set, i.e. the most signif. bit set */
422 ms_discrep_bit = fls64(d) - 1;
423 dev_dbg(&ds1wm_data->pdev->dev,
424 "pass: %d new d:%0#18llx MS discrep bit:%d\n",
425 pass, d, ms_discrep_bit);
426
427 /* prev_ms_discrep_bit = ms_discrep_bit;
428 prepare for next ROM search: */
429 if (ms_discrep_bit == -1)
430 break;
431
432 r = (r & ~(~0ull << (ms_discrep_bit))) | 1 << ms_discrep_bit;
433 } /* end while true */
434 dev_dbg(&ds1wm_data->pdev->dev,
435 "pass: %d total: %d search done ms d bit pos: %d\n", pass,
436 slaves_found, ms_discrep_bit);
437 }
438
439 /* --------------------------------------------------------------------- */
440
441 static struct w1_bus_master ds1wm_master = {
442 .read_byte = ds1wm_read_byte,
443 .write_byte = ds1wm_write_byte,
444 .reset_bus = ds1wm_reset_bus,
445 .search = ds1wm_search,
446 };
447
ds1wm_probe(struct platform_device * pdev)448 static int ds1wm_probe(struct platform_device *pdev)
449 {
450 struct ds1wm_data *ds1wm_data;
451 struct ds1wm_driver_data *plat;
452 struct resource *res;
453 int ret;
454
455 if (!pdev)
456 return -ENODEV;
457
458 ds1wm_data = kzalloc(sizeof(*ds1wm_data), GFP_KERNEL);
459 if (!ds1wm_data)
460 return -ENOMEM;
461
462 platform_set_drvdata(pdev, ds1wm_data);
463
464 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
465 if (!res) {
466 ret = -ENXIO;
467 goto err0;
468 }
469 ds1wm_data->map = ioremap(res->start, resource_size(res));
470 if (!ds1wm_data->map) {
471 ret = -ENOMEM;
472 goto err0;
473 }
474
475 /* calculate bus shift from mem resource */
476 ds1wm_data->bus_shift = resource_size(res) >> 3;
477
478 ds1wm_data->pdev = pdev;
479 ds1wm_data->cell = mfd_get_cell(pdev);
480 if (!ds1wm_data->cell) {
481 ret = -ENODEV;
482 goto err1;
483 }
484 plat = pdev->dev.platform_data;
485 if (!plat) {
486 ret = -ENODEV;
487 goto err1;
488 }
489
490 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
491 if (!res) {
492 ret = -ENXIO;
493 goto err1;
494 }
495 ds1wm_data->irq = res->start;
496 ds1wm_data->int_en_reg_none = (plat->active_high ? DS1WM_INTEN_IAS : 0);
497 ds1wm_data->reset_recover_delay = plat->reset_recover_delay;
498
499 if (res->flags & IORESOURCE_IRQ_HIGHEDGE)
500 irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_RISING);
501 if (res->flags & IORESOURCE_IRQ_LOWEDGE)
502 irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_FALLING);
503
504 ret = request_irq(ds1wm_data->irq, ds1wm_isr,
505 IRQF_DISABLED | IRQF_SHARED, "ds1wm", ds1wm_data);
506 if (ret)
507 goto err1;
508
509 ds1wm_up(ds1wm_data);
510
511 ds1wm_master.data = (void *)ds1wm_data;
512
513 ret = w1_add_master_device(&ds1wm_master);
514 if (ret)
515 goto err2;
516
517 return 0;
518
519 err2:
520 ds1wm_down(ds1wm_data);
521 free_irq(ds1wm_data->irq, ds1wm_data);
522 err1:
523 iounmap(ds1wm_data->map);
524 err0:
525 kfree(ds1wm_data);
526
527 return ret;
528 }
529
530 #ifdef CONFIG_PM
ds1wm_suspend(struct platform_device * pdev,pm_message_t state)531 static int ds1wm_suspend(struct platform_device *pdev, pm_message_t state)
532 {
533 struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
534
535 ds1wm_down(ds1wm_data);
536
537 return 0;
538 }
539
ds1wm_resume(struct platform_device * pdev)540 static int ds1wm_resume(struct platform_device *pdev)
541 {
542 struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
543
544 ds1wm_up(ds1wm_data);
545
546 return 0;
547 }
548 #else
549 #define ds1wm_suspend NULL
550 #define ds1wm_resume NULL
551 #endif
552
ds1wm_remove(struct platform_device * pdev)553 static int ds1wm_remove(struct platform_device *pdev)
554 {
555 struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
556
557 w1_remove_master_device(&ds1wm_master);
558 ds1wm_down(ds1wm_data);
559 free_irq(ds1wm_data->irq, ds1wm_data);
560 iounmap(ds1wm_data->map);
561 kfree(ds1wm_data);
562
563 return 0;
564 }
565
566 static struct platform_driver ds1wm_driver = {
567 .driver = {
568 .name = "ds1wm",
569 },
570 .probe = ds1wm_probe,
571 .remove = ds1wm_remove,
572 .suspend = ds1wm_suspend,
573 .resume = ds1wm_resume
574 };
575
ds1wm_init(void)576 static int __init ds1wm_init(void)
577 {
578 printk("DS1WM w1 busmaster driver - (c) 2004 Szabolcs Gyurko\n");
579 return platform_driver_register(&ds1wm_driver);
580 }
581
ds1wm_exit(void)582 static void __exit ds1wm_exit(void)
583 {
584 platform_driver_unregister(&ds1wm_driver);
585 }
586
587 module_init(ds1wm_init);
588 module_exit(ds1wm_exit);
589
590 MODULE_LICENSE("GPL");
591 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
592 "Matt Reimer <mreimer@vpop.net>,"
593 "Jean-Francois Dagenais <dagenaisj@sonatest.com>");
594 MODULE_DESCRIPTION("DS1WM w1 busmaster driver");
595