ARM: OMAP2+: add missing lateinit hook for calling pm late init
[linux-2.6/btrfs-unstable.git] / drivers / w1 / masters / ds1wm.c
blob96cab6ac2b4e6fdda01cff9d5bdb7d185fb1f82f
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).
6 * Copyright (c) 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
7 * Copyright (c) 2004-2007, Matt Reimer <mreimer@vpop.net>
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.
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/pm.h>
19 #include <linux/platform_device.h>
20 #include <linux/err.h>
21 #include <linux/delay.h>
22 #include <linux/mfd/core.h>
23 #include <linux/mfd/ds1wm.h>
24 #include <linux/slab.h>
26 #include <asm/io.h>
28 #include "../w1.h"
29 #include "../w1_int.h"
32 #define DS1WM_CMD 0x00 /* R/W 4 bits command */
33 #define DS1WM_DATA 0x01 /* R/W 8 bits, transmit/receive buffer */
34 #define DS1WM_INT 0x02 /* R/W interrupt status */
35 #define DS1WM_INT_EN 0x03 /* R/W interrupt enable */
36 #define DS1WM_CLKDIV 0x04 /* R/W 5 bits of divisor and pre-scale */
37 #define DS1WM_CNTRL 0x05 /* R/W master control register (not used yet) */
39 #define DS1WM_CMD_1W_RESET (1 << 0) /* force reset on 1-wire bus */
40 #define DS1WM_CMD_SRA (1 << 1) /* enable Search ROM accelerator mode */
41 #define DS1WM_CMD_DQ_OUTPUT (1 << 2) /* write only - forces bus low */
42 #define DS1WM_CMD_DQ_INPUT (1 << 3) /* read only - reflects state of bus */
43 #define DS1WM_CMD_RST (1 << 5) /* software reset */
44 #define DS1WM_CMD_OD (1 << 7) /* overdrive */
46 #define DS1WM_INT_PD (1 << 0) /* presence detect */
47 #define DS1WM_INT_PDR (1 << 1) /* presence detect result */
48 #define DS1WM_INT_TBE (1 << 2) /* tx buffer empty */
49 #define DS1WM_INT_TSRE (1 << 3) /* tx shift register empty */
50 #define DS1WM_INT_RBF (1 << 4) /* rx buffer full */
51 #define DS1WM_INT_RSRF (1 << 5) /* rx shift register full */
53 #define DS1WM_INTEN_EPD (1 << 0) /* enable presence detect int */
54 #define DS1WM_INTEN_IAS (1 << 1) /* INTR active state */
55 #define DS1WM_INTEN_ETBE (1 << 2) /* enable tx buffer empty int */
56 #define DS1WM_INTEN_ETMT (1 << 3) /* enable tx shift register empty int */
57 #define DS1WM_INTEN_ERBF (1 << 4) /* enable rx buffer full int */
58 #define DS1WM_INTEN_ERSRF (1 << 5) /* enable rx shift register full int */
59 #define DS1WM_INTEN_DQO (1 << 6) /* enable direct bus driving ops */
61 #define DS1WM_INTEN_NOT_IAS (~DS1WM_INTEN_IAS) /* all but INTR active state */
63 #define DS1WM_TIMEOUT (HZ * 5)
65 static struct {
66 unsigned long freq;
67 unsigned long divisor;
68 } freq[] = {
69 { 1000000, 0x80 },
70 { 2000000, 0x84 },
71 { 3000000, 0x81 },
72 { 4000000, 0x88 },
73 { 5000000, 0x82 },
74 { 6000000, 0x85 },
75 { 7000000, 0x83 },
76 { 8000000, 0x8c },
77 { 10000000, 0x86 },
78 { 12000000, 0x89 },
79 { 14000000, 0x87 },
80 { 16000000, 0x90 },
81 { 20000000, 0x8a },
82 { 24000000, 0x8d },
83 { 28000000, 0x8b },
84 { 32000000, 0x94 },
85 { 40000000, 0x8e },
86 { 48000000, 0x91 },
87 { 56000000, 0x8f },
88 { 64000000, 0x98 },
89 { 80000000, 0x92 },
90 { 96000000, 0x95 },
91 { 112000000, 0x93 },
92 { 128000000, 0x9c },
93 /* you can continue this table, consult the OPERATION - CLOCK DIVISOR
94 section of the ds1wm spec sheet. */
97 struct ds1wm_data {
98 void __iomem *map;
99 int bus_shift; /* # of shifts to calc register offsets */
100 struct platform_device *pdev;
101 const struct mfd_cell *cell;
102 int irq;
103 int slave_present;
104 void *reset_complete;
105 void *read_complete;
106 void *write_complete;
107 int read_error;
108 /* last byte received */
109 u8 read_byte;
110 /* byte to write that makes all intr disabled, */
111 /* considering active_state (IAS) (optimization) */
112 u8 int_en_reg_none;
113 unsigned int reset_recover_delay; /* see ds1wm.h */
116 static inline void ds1wm_write_register(struct ds1wm_data *ds1wm_data, u32 reg,
117 u8 val)
119 __raw_writeb(val, ds1wm_data->map + (reg << ds1wm_data->bus_shift));
122 static inline u8 ds1wm_read_register(struct ds1wm_data *ds1wm_data, u32 reg)
124 return __raw_readb(ds1wm_data->map + (reg << ds1wm_data->bus_shift));
128 static irqreturn_t ds1wm_isr(int isr, void *data)
130 struct ds1wm_data *ds1wm_data = data;
131 u8 intr;
132 u8 inten = ds1wm_read_register(ds1wm_data, DS1WM_INT_EN);
133 /* if no bits are set in int enable register (except the IAS)
134 than go no further, reading the regs below has side effects */
135 if (!(inten & DS1WM_INTEN_NOT_IAS))
136 return IRQ_NONE;
138 ds1wm_write_register(ds1wm_data,
139 DS1WM_INT_EN, ds1wm_data->int_en_reg_none);
141 /* this read action clears the INTR and certain flags in ds1wm */
142 intr = ds1wm_read_register(ds1wm_data, DS1WM_INT);
144 ds1wm_data->slave_present = (intr & DS1WM_INT_PDR) ? 0 : 1;
146 if ((intr & DS1WM_INT_TSRE) && ds1wm_data->write_complete) {
147 inten &= ~DS1WM_INTEN_ETMT;
148 complete(ds1wm_data->write_complete);
150 if (intr & DS1WM_INT_RBF) {
151 /* this read clears the RBF flag */
152 ds1wm_data->read_byte = ds1wm_read_register(ds1wm_data,
153 DS1WM_DATA);
154 inten &= ~DS1WM_INTEN_ERBF;
155 if (ds1wm_data->read_complete)
156 complete(ds1wm_data->read_complete);
158 if ((intr & DS1WM_INT_PD) && ds1wm_data->reset_complete) {
159 inten &= ~DS1WM_INTEN_EPD;
160 complete(ds1wm_data->reset_complete);
163 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, inten);
164 return IRQ_HANDLED;
167 static int ds1wm_reset(struct ds1wm_data *ds1wm_data)
169 unsigned long timeleft;
170 DECLARE_COMPLETION_ONSTACK(reset_done);
172 ds1wm_data->reset_complete = &reset_done;
174 /* enable Presence detect only */
175 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, DS1WM_INTEN_EPD |
176 ds1wm_data->int_en_reg_none);
178 ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_1W_RESET);
180 timeleft = wait_for_completion_timeout(&reset_done, DS1WM_TIMEOUT);
181 ds1wm_data->reset_complete = NULL;
182 if (!timeleft) {
183 dev_err(&ds1wm_data->pdev->dev, "reset failed, timed out\n");
184 return 1;
187 if (!ds1wm_data->slave_present) {
188 dev_dbg(&ds1wm_data->pdev->dev, "reset: no devices found\n");
189 return 1;
192 if (ds1wm_data->reset_recover_delay)
193 msleep(ds1wm_data->reset_recover_delay);
195 return 0;
198 static int ds1wm_write(struct ds1wm_data *ds1wm_data, u8 data)
200 unsigned long timeleft;
201 DECLARE_COMPLETION_ONSTACK(write_done);
202 ds1wm_data->write_complete = &write_done;
204 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN,
205 ds1wm_data->int_en_reg_none | DS1WM_INTEN_ETMT);
207 ds1wm_write_register(ds1wm_data, DS1WM_DATA, data);
209 timeleft = wait_for_completion_timeout(&write_done, DS1WM_TIMEOUT);
211 ds1wm_data->write_complete = NULL;
212 if (!timeleft) {
213 dev_err(&ds1wm_data->pdev->dev, "write failed, timed out\n");
214 return -ETIMEDOUT;
217 return 0;
220 static u8 ds1wm_read(struct ds1wm_data *ds1wm_data, unsigned char write_data)
222 unsigned long timeleft;
223 u8 intEnable = DS1WM_INTEN_ERBF | ds1wm_data->int_en_reg_none;
224 DECLARE_COMPLETION_ONSTACK(read_done);
226 ds1wm_read_register(ds1wm_data, DS1WM_DATA);
228 ds1wm_data->read_complete = &read_done;
229 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, intEnable);
231 ds1wm_write_register(ds1wm_data, DS1WM_DATA, write_data);
232 timeleft = wait_for_completion_timeout(&read_done, DS1WM_TIMEOUT);
234 ds1wm_data->read_complete = NULL;
235 if (!timeleft) {
236 dev_err(&ds1wm_data->pdev->dev, "read failed, timed out\n");
237 ds1wm_data->read_error = -ETIMEDOUT;
238 return 0xFF;
240 ds1wm_data->read_error = 0;
241 return ds1wm_data->read_byte;
244 static int ds1wm_find_divisor(int gclk)
246 int i;
248 for (i = ARRAY_SIZE(freq)-1; i >= 0; --i)
249 if (gclk >= freq[i].freq)
250 return freq[i].divisor;
252 return 0;
255 static void ds1wm_up(struct ds1wm_data *ds1wm_data)
257 int divisor;
258 struct ds1wm_driver_data *plat = ds1wm_data->pdev->dev.platform_data;
260 if (ds1wm_data->cell->enable)
261 ds1wm_data->cell->enable(ds1wm_data->pdev);
263 divisor = ds1wm_find_divisor(plat->clock_rate);
264 dev_dbg(&ds1wm_data->pdev->dev,
265 "found divisor 0x%x for clock %d\n", divisor, plat->clock_rate);
266 if (divisor == 0) {
267 dev_err(&ds1wm_data->pdev->dev,
268 "no suitable divisor for %dHz clock\n",
269 plat->clock_rate);
270 return;
272 ds1wm_write_register(ds1wm_data, DS1WM_CLKDIV, divisor);
274 /* Let the w1 clock stabilize. */
275 msleep(1);
277 ds1wm_reset(ds1wm_data);
280 static void ds1wm_down(struct ds1wm_data *ds1wm_data)
282 ds1wm_reset(ds1wm_data);
284 /* Disable interrupts. */
285 ds1wm_write_register(ds1wm_data, DS1WM_INT_EN,
286 ds1wm_data->int_en_reg_none);
288 if (ds1wm_data->cell->disable)
289 ds1wm_data->cell->disable(ds1wm_data->pdev);
292 /* --------------------------------------------------------------------- */
293 /* w1 methods */
295 static u8 ds1wm_read_byte(void *data)
297 struct ds1wm_data *ds1wm_data = data;
299 return ds1wm_read(ds1wm_data, 0xff);
302 static void ds1wm_write_byte(void *data, u8 byte)
304 struct ds1wm_data *ds1wm_data = data;
306 ds1wm_write(ds1wm_data, byte);
309 static u8 ds1wm_reset_bus(void *data)
311 struct ds1wm_data *ds1wm_data = data;
313 ds1wm_reset(ds1wm_data);
315 return 0;
318 static void ds1wm_search(void *data, struct w1_master *master_dev,
319 u8 search_type, w1_slave_found_callback slave_found)
321 struct ds1wm_data *ds1wm_data = data;
322 int i;
323 int ms_discrep_bit = -1;
324 u64 r = 0; /* holds the progress of the search */
325 u64 r_prime, d;
326 unsigned slaves_found = 0;
327 unsigned int pass = 0;
329 dev_dbg(&ds1wm_data->pdev->dev, "search begin\n");
330 while (true) {
331 ++pass;
332 if (pass > 100) {
333 dev_dbg(&ds1wm_data->pdev->dev,
334 "too many attempts (100), search aborted\n");
335 return;
338 mutex_lock(&master_dev->bus_mutex);
339 if (ds1wm_reset(ds1wm_data)) {
340 mutex_unlock(&master_dev->bus_mutex);
341 dev_dbg(&ds1wm_data->pdev->dev,
342 "pass: %d reset error (or no slaves)\n", pass);
343 break;
346 dev_dbg(&ds1wm_data->pdev->dev,
347 "pass: %d r : %0#18llx writing SEARCH_ROM\n", pass, r);
348 ds1wm_write(ds1wm_data, search_type);
349 dev_dbg(&ds1wm_data->pdev->dev,
350 "pass: %d entering ASM\n", pass);
351 ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_SRA);
352 dev_dbg(&ds1wm_data->pdev->dev,
353 "pass: %d beginning nibble loop\n", pass);
355 r_prime = 0;
356 d = 0;
357 /* we work one nibble at a time */
358 /* each nibble is interleaved to form a byte */
359 for (i = 0; i < 16; i++) {
361 unsigned char resp, _r, _r_prime, _d;
363 _r = (r >> (4*i)) & 0xf;
364 _r = ((_r & 0x1) << 1) |
365 ((_r & 0x2) << 2) |
366 ((_r & 0x4) << 3) |
367 ((_r & 0x8) << 4);
369 /* writes _r, then reads back: */
370 resp = ds1wm_read(ds1wm_data, _r);
372 if (ds1wm_data->read_error) {
373 dev_err(&ds1wm_data->pdev->dev,
374 "pass: %d nibble: %d read error\n", pass, i);
375 break;
378 _r_prime = ((resp & 0x02) >> 1) |
379 ((resp & 0x08) >> 2) |
380 ((resp & 0x20) >> 3) |
381 ((resp & 0x80) >> 4);
383 _d = ((resp & 0x01) >> 0) |
384 ((resp & 0x04) >> 1) |
385 ((resp & 0x10) >> 2) |
386 ((resp & 0x40) >> 3);
388 r_prime |= (unsigned long long) _r_prime << (i * 4);
389 d |= (unsigned long long) _d << (i * 4);
392 if (ds1wm_data->read_error) {
393 mutex_unlock(&master_dev->bus_mutex);
394 dev_err(&ds1wm_data->pdev->dev,
395 "pass: %d read error, retrying\n", pass);
396 break;
398 dev_dbg(&ds1wm_data->pdev->dev,
399 "pass: %d r\': %0#18llx d:%0#18llx\n",
400 pass, r_prime, d);
401 dev_dbg(&ds1wm_data->pdev->dev,
402 "pass: %d nibble loop complete, exiting ASM\n", pass);
403 ds1wm_write_register(ds1wm_data, DS1WM_CMD, ~DS1WM_CMD_SRA);
404 dev_dbg(&ds1wm_data->pdev->dev,
405 "pass: %d resetting bus\n", pass);
406 ds1wm_reset(ds1wm_data);
407 mutex_unlock(&master_dev->bus_mutex);
408 if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) {
409 dev_err(&ds1wm_data->pdev->dev,
410 "pass: %d bus error, retrying\n", pass);
411 continue; /* start over */
415 dev_dbg(&ds1wm_data->pdev->dev,
416 "pass: %d found %0#18llx\n", pass, r_prime);
417 slave_found(master_dev, r_prime);
418 ++slaves_found;
419 dev_dbg(&ds1wm_data->pdev->dev,
420 "pass: %d complete, preparing next pass\n", pass);
422 /* any discrepency found which we already choose the
423 '1' branch is now is now irrelevant we reveal the
424 next branch with this: */
425 d &= ~r;
426 /* find last bit set, i.e. the most signif. bit set */
427 ms_discrep_bit = fls64(d) - 1;
428 dev_dbg(&ds1wm_data->pdev->dev,
429 "pass: %d new d:%0#18llx MS discrep bit:%d\n",
430 pass, d, ms_discrep_bit);
432 /* prev_ms_discrep_bit = ms_discrep_bit;
433 prepare for next ROM search: */
434 if (ms_discrep_bit == -1)
435 break;
437 r = (r & ~(~0ull << (ms_discrep_bit))) | 1 << ms_discrep_bit;
438 } /* end while true */
439 dev_dbg(&ds1wm_data->pdev->dev,
440 "pass: %d total: %d search done ms d bit pos: %d\n", pass,
441 slaves_found, ms_discrep_bit);
444 /* --------------------------------------------------------------------- */
446 static struct w1_bus_master ds1wm_master = {
447 .read_byte = ds1wm_read_byte,
448 .write_byte = ds1wm_write_byte,
449 .reset_bus = ds1wm_reset_bus,
450 .search = ds1wm_search,
453 static int ds1wm_probe(struct platform_device *pdev)
455 struct ds1wm_data *ds1wm_data;
456 struct ds1wm_driver_data *plat;
457 struct resource *res;
458 int ret;
460 if (!pdev)
461 return -ENODEV;
463 ds1wm_data = devm_kzalloc(&pdev->dev, sizeof(*ds1wm_data), GFP_KERNEL);
464 if (!ds1wm_data)
465 return -ENOMEM;
467 platform_set_drvdata(pdev, ds1wm_data);
469 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
470 if (!res)
471 return -ENXIO;
472 ds1wm_data->map = devm_ioremap(&pdev->dev, res->start,
473 resource_size(res));
474 if (!ds1wm_data->map)
475 return -ENOMEM;
477 /* calculate bus shift from mem resource */
478 ds1wm_data->bus_shift = resource_size(res) >> 3;
480 ds1wm_data->pdev = pdev;
481 ds1wm_data->cell = mfd_get_cell(pdev);
482 if (!ds1wm_data->cell)
483 return -ENODEV;
484 plat = pdev->dev.platform_data;
485 if (!plat)
486 return -ENODEV;
488 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
489 if (!res)
490 return -ENXIO;
491 ds1wm_data->irq = res->start;
492 ds1wm_data->int_en_reg_none = (plat->active_high ? DS1WM_INTEN_IAS : 0);
493 ds1wm_data->reset_recover_delay = plat->reset_recover_delay;
495 if (res->flags & IORESOURCE_IRQ_HIGHEDGE)
496 irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_RISING);
497 if (res->flags & IORESOURCE_IRQ_LOWEDGE)
498 irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_FALLING);
500 ret = devm_request_irq(&pdev->dev, ds1wm_data->irq, ds1wm_isr,
501 IRQF_DISABLED | IRQF_SHARED, "ds1wm", ds1wm_data);
502 if (ret)
503 return ret;
505 ds1wm_up(ds1wm_data);
507 ds1wm_master.data = (void *)ds1wm_data;
509 ret = w1_add_master_device(&ds1wm_master);
510 if (ret)
511 goto err;
513 return 0;
515 err:
516 ds1wm_down(ds1wm_data);
518 return ret;
521 #ifdef CONFIG_PM
522 static int ds1wm_suspend(struct platform_device *pdev, pm_message_t state)
524 struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
526 ds1wm_down(ds1wm_data);
528 return 0;
531 static int ds1wm_resume(struct platform_device *pdev)
533 struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
535 ds1wm_up(ds1wm_data);
537 return 0;
539 #else
540 #define ds1wm_suspend NULL
541 #define ds1wm_resume NULL
542 #endif
544 static int ds1wm_remove(struct platform_device *pdev)
546 struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
548 w1_remove_master_device(&ds1wm_master);
549 ds1wm_down(ds1wm_data);
551 return 0;
554 static struct platform_driver ds1wm_driver = {
555 .driver = {
556 .name = "ds1wm",
558 .probe = ds1wm_probe,
559 .remove = ds1wm_remove,
560 .suspend = ds1wm_suspend,
561 .resume = ds1wm_resume
564 static int __init ds1wm_init(void)
566 printk("DS1WM w1 busmaster driver - (c) 2004 Szabolcs Gyurko\n");
567 return platform_driver_register(&ds1wm_driver);
570 static void __exit ds1wm_exit(void)
572 platform_driver_unregister(&ds1wm_driver);
575 module_init(ds1wm_init);
576 module_exit(ds1wm_exit);
578 MODULE_LICENSE("GPL");
579 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
580 "Matt Reimer <mreimer@vpop.net>,"
581 "Jean-Francois Dagenais <dagenaisj@sonatest.com>");
582 MODULE_DESCRIPTION("DS1WM w1 busmaster driver");