dwiic.c revision 1.11 1 /* $NetBSD: dwiic.c,v 1.11 2025/09/15 15:18:42 thorpej Exp $ */
2
3 /* $OpenBSD: dwiic.c,v 1.4 2018/05/23 22:08:00 kettenis Exp $ */
4
5 /*-
6 * Copyright (c) 2017 The NetBSD Foundation, Inc.
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Manuel Bouyer.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33 /*
34 * Synopsys DesignWare I2C controller
35 *
36 * Copyright (c) 2015, 2016 joshua stein <jcs (at) openbsd.org>
37 *
38 * Permission to use, copy, modify, and/or distribute this software for any
39 * purpose with or without fee is hereby granted, provided that the above
40 * copyright notice and this permission notice appear in all copies.
41 *
42 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
43 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
44 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
45 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
46 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
47 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
48 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
49 */
50
51 #include <sys/cdefs.h>
52 __KERNEL_RCSID(0, "$NetBSD: dwiic.c,v 1.11 2025/09/15 15:18:42 thorpej Exp $");
53
54 #include <sys/param.h>
55
56 #include <sys/atomic.h>
57 #include <sys/bus.h>
58 #include <sys/device.h>
59 #include <sys/kernel.h>
60 #include <sys/systm.h>
61
62 #include <dev/ic/dwiic_var.h>
63
64 //#define DWIIC_DEBUG
65
66 #ifdef DWIIC_DEBUG
67 #define DPRINTF(x) printf x
68 #else
69 #define DPRINTF(x)
70 #endif
71
72 /* register offsets */
73 #define DW_IC_CON 0x0
74 #define DW_IC_TAR 0x4
75 #define DW_IC_DATA_CMD 0x10
76 #define DW_IC_SS_SCL_HCNT 0x14
77 #define DW_IC_SS_SCL_LCNT 0x18
78 #define DW_IC_FS_SCL_HCNT 0x1c
79 #define DW_IC_FS_SCL_LCNT 0x20
80 #define DW_IC_INTR_STAT 0x2c
81 #define DW_IC_INTR_MASK 0x30
82 #define DW_IC_RAW_INTR_STAT 0x34
83 #define DW_IC_RX_TL 0x38
84 #define DW_IC_TX_TL 0x3c
85 #define DW_IC_CLR_INTR 0x40
86 #define DW_IC_CLR_RX_UNDER 0x44
87 #define DW_IC_CLR_RX_OVER 0x48
88 #define DW_IC_CLR_TX_OVER 0x4c
89 #define DW_IC_CLR_RD_REQ 0x50
90 #define DW_IC_CLR_TX_ABRT 0x54
91 #define DW_IC_CLR_RX_DONE 0x58
92 #define DW_IC_CLR_ACTIVITY 0x5c
93 #define DW_IC_CLR_STOP_DET 0x60
94 #define DW_IC_CLR_START_DET 0x64
95 #define DW_IC_CLR_GEN_CALL 0x68
96 #define DW_IC_ENABLE 0x6c
97 #define DW_IC_STATUS 0x70
98 #define DW_IC_TXFLR 0x74
99 #define DW_IC_RXFLR 0x78
100 #define DW_IC_SDA_HOLD 0x7c
101 #define DW_IC_TX_ABRT_SOURCE 0x80
102 #define DW_IC_ENABLE_STATUS 0x9c
103 #define DW_IC_COMP_PARAM_1 0xf4
104 #define DW_IC_COMP_VERSION 0xf8
105 #define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A
106 #define DW_IC_COMP_TYPE 0xfc
107 #define DW_IC_COMP_TYPE_VALUE 0x44570140
108
109 #define DW_IC_CON_MASTER 0x1
110 #define DW_IC_CON_SPEED_STD 0x2
111 #define DW_IC_CON_SPEED_FAST 0x4
112 #define DW_IC_CON_10BITADDR_MASTER 0x10
113 #define DW_IC_CON_RESTART_EN 0x20
114 #define DW_IC_CON_SLAVE_DISABLE 0x40
115
116 #define DW_IC_DATA_CMD_READ 0x100
117 #define DW_IC_DATA_CMD_STOP 0x200
118 #define DW_IC_DATA_CMD_RESTART 0x400
119
120 #define DW_IC_INTR_RX_UNDER 0x001
121 #define DW_IC_INTR_RX_OVER 0x002
122 #define DW_IC_INTR_RX_FULL 0x004
123 #define DW_IC_INTR_TX_OVER 0x008
124 #define DW_IC_INTR_TX_EMPTY 0x010
125 #define DW_IC_INTR_RD_REQ 0x020
126 #define DW_IC_INTR_TX_ABRT 0x040
127 #define DW_IC_INTR_RX_DONE 0x080
128 #define DW_IC_INTR_ACTIVITY 0x100
129 #define DW_IC_INTR_STOP_DET 0x200
130 #define DW_IC_INTR_START_DET 0x400
131 #define DW_IC_INTR_GEN_CALL 0x800
132
133 #define DW_IC_STATUS_ACTIVITY 0x1
134
135 /* hardware abort codes from the DW_IC_TX_ABRT_SOURCE register */
136 #define ABRT_7B_ADDR_NOACK 0
137 #define ABRT_10ADDR1_NOACK 1
138 #define ABRT_10ADDR2_NOACK 2
139 #define ABRT_TXDATA_NOACK 3
140 #define ABRT_GCALL_NOACK 4
141 #define ABRT_GCALL_READ 5
142 #define ABRT_SBYTE_ACKDET 7
143 #define ABRT_SBYTE_NORSTRT 9
144 #define ABRT_10B_RD_NORSTRT 10
145 #define ABRT_MASTER_DIS 11
146 #define ARB_LOST 12
147
148 static int dwiic_init(struct dwiic_softc *);
149 static void dwiic_enable(struct dwiic_softc *, bool);
150 static uint32_t dwiic_read(struct dwiic_softc *, int);
151 static void dwiic_write(struct dwiic_softc *, int, uint32_t);
152 static int dwiic_i2c_exec(void *, i2c_op_t, i2c_addr_t, const void *,
153 size_t, void *, size_t, int);
154
155 bool
156 dwiic_attach(struct dwiic_softc *sc)
157 {
158 if (sc->sc_power != NULL) {
159 if (!sc->sc_power(sc, 1)) {
160 aprint_error_dev(sc->sc_dev, "failed to power up\n");
161 return 0;
162 }
163 }
164
165 /* fetch timing parameters */
166 if (sc->ss_hcnt == 0)
167 sc->ss_hcnt = dwiic_read(sc, DW_IC_SS_SCL_HCNT);
168 if (sc->ss_lcnt == 0)
169 sc->ss_lcnt = dwiic_read(sc, DW_IC_SS_SCL_LCNT);
170 if (sc->fs_hcnt == 0)
171 sc->fs_hcnt = dwiic_read(sc, DW_IC_FS_SCL_HCNT);
172 if (sc->fs_lcnt == 0)
173 sc->fs_lcnt = dwiic_read(sc, DW_IC_FS_SCL_LCNT);
174 if (sc->sda_hold_time == 0)
175 sc->sda_hold_time = dwiic_read(sc, DW_IC_SDA_HOLD);
176
177 if (dwiic_init(sc)) {
178 aprint_error_dev(sc->sc_dev, "failed initializing\n");
179 return 0;
180 }
181
182 /* leave the controller disabled */
183 dwiic_write(sc, DW_IC_INTR_MASK, 0);
184 dwiic_enable(sc, 0);
185 dwiic_read(sc, DW_IC_CLR_INTR);
186
187 mutex_init(&sc->sc_int_lock, MUTEX_DEFAULT, IPL_VM);
188 cv_init(&sc->sc_int_readwait, "dwiicr");
189 cv_init(&sc->sc_int_writewait, "dwiicw");
190 cv_init(&sc->sc_int_stopwait, "dwiics");
191
192 /* setup and attach iic bus */
193 iic_tag_init(&sc->sc_i2c_tag);
194 sc->sc_i2c_tag.ic_cookie = sc;
195 sc->sc_i2c_tag.ic_exec = dwiic_i2c_exec;
196
197 /* config_found for "i2cbus" is done in the bus-attachment glue */
198
199 atomic_store_release(&sc->sc_attached, true);
200
201 return 1;
202 }
203
204 int
205 dwiic_detach(device_t self, int flags)
206 {
207 struct dwiic_softc *sc = device_private(self);
208
209 dwiic_enable(sc, 0);
210 if (sc->sc_ih != NULL) {
211 intr_disestablish(sc->sc_ih);
212 sc->sc_ih = NULL;
213 }
214
215 return 0;
216 }
217
218 bool
219 dwiic_suspend(device_t self, const pmf_qual_t *qual)
220 {
221 struct dwiic_softc *sc = device_private(self);
222
223 /* disable controller */
224 dwiic_enable(sc, 0);
225
226 /* disable interrupts */
227 dwiic_write(sc, DW_IC_INTR_MASK, 0);
228 dwiic_read(sc, DW_IC_CLR_INTR);
229 if (sc->sc_power != NULL) {
230 if (!sc->sc_power(sc, 0)) {
231 device_printf(sc->sc_dev, "failed to power off\n");
232 }
233 }
234 return true;
235 }
236
237 bool
238 dwiic_resume(device_t self, const pmf_qual_t *qual)
239 {
240 struct dwiic_softc *sc = device_private(self);
241 if (sc->sc_power != NULL) {
242 if (!sc->sc_power(sc, 1)) {
243 device_printf(sc->sc_dev, "failed to power up\n");
244 return false;
245 }
246 }
247 dwiic_init(sc);
248 return true;
249 }
250
251 static uint32_t
252 dwiic_read(struct dwiic_softc *sc, int offset)
253 {
254 u_int32_t b = bus_space_read_4(sc->sc_iot, sc->sc_ioh, offset);
255
256 DPRINTF(("%s: read at 0x%x = 0x%x\n", device_xname(sc->sc_dev), offset, b));
257
258 return b;
259 }
260
261 static void
262 dwiic_write(struct dwiic_softc *sc, int offset, uint32_t val)
263 {
264 bus_space_write_4(sc->sc_iot, sc->sc_ioh, offset, val);
265
266 DPRINTF(("%s: write at 0x%x: 0x%x\n", device_xname(sc->sc_dev), offset,
267 val));
268 }
269
270 static int
271 dwiic_init(struct dwiic_softc *sc)
272 {
273 uint32_t reg;
274
275 /* make sure we're talking to a device we know */
276 reg = dwiic_read(sc, DW_IC_COMP_TYPE);
277 if (reg != DW_IC_COMP_TYPE_VALUE) {
278 DPRINTF(("%s: invalid component type 0x%x\n",
279 device_xname(sc->sc_dev), reg));
280 return 1;
281 }
282
283 /* disable the adapter */
284 dwiic_enable(sc, 0);
285
286 /* write standard-mode SCL timing parameters */
287 dwiic_write(sc, DW_IC_SS_SCL_HCNT, sc->ss_hcnt);
288 dwiic_write(sc, DW_IC_SS_SCL_LCNT, sc->ss_lcnt);
289
290 /* and fast-mode SCL timing parameters */
291 dwiic_write(sc, DW_IC_FS_SCL_HCNT, sc->fs_hcnt);
292 dwiic_write(sc, DW_IC_FS_SCL_LCNT, sc->fs_lcnt);
293
294 /* SDA hold time */
295 reg = dwiic_read(sc, DW_IC_COMP_VERSION);
296 if (reg >= DW_IC_SDA_HOLD_MIN_VERS)
297 dwiic_write(sc, DW_IC_SDA_HOLD, sc->sda_hold_time);
298
299 /* FIFO threshold levels */
300 sc->tx_fifo_depth = 32;
301 sc->rx_fifo_depth = 32;
302 dwiic_write(sc, DW_IC_TX_TL, sc->tx_fifo_depth / 2);
303 dwiic_write(sc, DW_IC_RX_TL, 0);
304
305 /* configure as i2c master with fast speed */
306 sc->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
307 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
308 dwiic_write(sc, DW_IC_CON, sc->master_cfg);
309
310 return 0;
311 }
312
313 static void
314 dwiic_enable(struct dwiic_softc *sc, bool enable)
315 {
316 int retries;
317
318 for (retries = 100; retries > 0; retries--) {
319 dwiic_write(sc, DW_IC_ENABLE, enable);
320 if ((dwiic_read(sc, DW_IC_ENABLE_STATUS) & 1) == enable)
321 return;
322
323 DELAY(25);
324 }
325
326 device_printf(sc->sc_dev, "failed to %sable\n",
327 (enable ? "en" : "dis"));
328 }
329
330 static int
331 dwiic_i2c_exec(void *cookie, i2c_op_t op, i2c_addr_t addr, const void *cmdbuf,
332 size_t cmdlen, void *buf, size_t len, int flags)
333 {
334 struct dwiic_softc *sc = cookie;
335 u_int32_t ic_con, st, cmd, resp;
336 int retries, tx_limit, rx_avail, x, readpos;
337 const uint8_t *bcmd;
338 uint8_t *bdata;
339
340 if (sc->sc_poll)
341 flags |= I2C_F_POLL;
342
343 DPRINTF(("%s: %s: op %d, addr 0x%02x, cmdlen %zu, len %zu, "
344 "flags 0x%02x\n", device_xname(sc->sc_dev), __func__, op, addr, cmdlen,
345 len, flags));
346
347 /* setup transfer */
348 sc->sc_i2c_xfer.op = op;
349 sc->sc_i2c_xfer.buf = buf;
350 sc->sc_i2c_xfer.len = len;
351 sc->sc_i2c_xfer.flags = flags;
352 sc->sc_i2c_xfer.error = 0;
353
354 /* wait for bus to be idle */
355 for (retries = 100; retries > 0; retries--) {
356 st = dwiic_read(sc, DW_IC_STATUS);
357 if (!(st & DW_IC_STATUS_ACTIVITY))
358 break;
359 DELAY(1000);
360 }
361 DPRINTF(("%s: %s: status 0x%x\n", device_xname(sc->sc_dev), __func__, st));
362 if (st & DW_IC_STATUS_ACTIVITY) {
363 return (1);
364 }
365
366 /* disable controller */
367 dwiic_enable(sc, 0);
368
369 /* set slave address */
370 ic_con = dwiic_read(sc, DW_IC_CON);
371 ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
372 dwiic_write(sc, DW_IC_CON, ic_con);
373 dwiic_write(sc, DW_IC_TAR, addr);
374
375 /* disable interrupts */
376 dwiic_write(sc, DW_IC_INTR_MASK, 0);
377 dwiic_read(sc, DW_IC_CLR_INTR);
378
379 /* enable controller */
380 dwiic_enable(sc, 1);
381
382 /* wait until the controller is ready for commands */
383 if (flags & I2C_F_POLL)
384 DELAY(200);
385 else {
386 mutex_enter(&sc->sc_int_lock);
387 dwiic_read(sc, DW_IC_CLR_INTR);
388 dwiic_write(sc, DW_IC_INTR_MASK, DW_IC_INTR_TX_EMPTY);
389
390 if (cv_timedwait(&sc->sc_int_writewait,
391 &sc->sc_int_lock, hz / 2) != 0)
392 device_printf(sc->sc_dev,
393 "timed out waiting for tx_empty intr\n");
394 dwiic_write(sc, DW_IC_INTR_MASK, 0);
395 dwiic_read(sc, DW_IC_CLR_INTR);
396 mutex_exit(&sc->sc_int_lock);
397 }
398
399 /* send our command, one byte at a time */
400 if (cmdlen > 0) {
401 bcmd = (const void *)cmdbuf;
402
403 DPRINTF(("%s: %s: sending cmd (len %zu):", device_xname(sc->sc_dev),
404 __func__, cmdlen));
405 for (x = 0; x < cmdlen; x++)
406 DPRINTF((" %02x", bcmd[x]));
407 DPRINTF(("\n"));
408
409 tx_limit = sc->tx_fifo_depth - dwiic_read(sc, DW_IC_TXFLR);
410 if (cmdlen > tx_limit) {
411 /* TODO */
412 device_printf(sc->sc_dev, "can't write %zu (> %d)\n",
413 cmdlen, tx_limit);
414 sc->sc_i2c_xfer.error = 1;
415 return (1);
416 }
417
418 for (x = 0; x < cmdlen; x++) {
419 cmd = bcmd[x];
420 /*
421 * Generate STOP condition if this is the last
422 * byte of the transfer.
423 */
424 if (x == (cmdlen - 1) && len == 0 && I2C_OP_STOP_P(op))
425 cmd |= DW_IC_DATA_CMD_STOP;
426 dwiic_write(sc, DW_IC_DATA_CMD, cmd);
427 }
428 }
429
430 bdata = (void *)buf;
431 x = readpos = 0;
432 tx_limit = sc->tx_fifo_depth - dwiic_read(sc, DW_IC_TXFLR);
433
434 DPRINTF(("%s: %s: need to read %zu bytes, can send %d read reqs\n",
435 device_xname(sc->sc_dev), __func__, len, tx_limit));
436
437 while (x < len) {
438 if (I2C_OP_WRITE_P(op))
439 cmd = bdata[x];
440 else
441 cmd = DW_IC_DATA_CMD_READ;
442
443 /*
444 * Generate RESTART condition if we're reversing
445 * direction.
446 */
447 if (x == 0 && cmdlen > 0 && I2C_OP_READ_P(op))
448 cmd |= DW_IC_DATA_CMD_RESTART;
449 /*
450 * Generate STOP condition on the last byte of the
451 * transfer.
452 */
453 if (x == (len - 1) && I2C_OP_STOP_P(op))
454 cmd |= DW_IC_DATA_CMD_STOP;
455
456 dwiic_write(sc, DW_IC_DATA_CMD, cmd);
457
458 tx_limit--;
459 x++;
460
461 /*
462 * As TXFLR fills up, we need to clear it out by reading all
463 * available data.
464 */
465 while (I2C_OP_READ_P(op) && (tx_limit == 0 || x == len)) {
466 DPRINTF(("%s: %s: tx_limit %d, sent %d read reqs\n",
467 device_xname(sc->sc_dev), __func__, tx_limit, x));
468
469 if (flags & I2C_F_POLL) {
470 for (retries = 100; retries > 0; retries--) {
471 rx_avail = dwiic_read(sc, DW_IC_RXFLR);
472 if (rx_avail > 0)
473 break;
474 DELAY(50);
475 }
476 } else {
477 mutex_enter(&sc->sc_int_lock);
478 dwiic_read(sc, DW_IC_CLR_INTR);
479 dwiic_write(sc, DW_IC_INTR_MASK,
480 DW_IC_INTR_RX_FULL);
481
482 if (cv_timedwait(&sc->sc_int_readwait,
483 &sc->sc_int_lock, hz / 2) != 0)
484 device_printf(sc->sc_dev,
485 "timed out waiting for "
486 "rx_full intr\n");
487
488 dwiic_write(sc, DW_IC_INTR_MASK, 0);
489 dwiic_read(sc, DW_IC_CLR_INTR);
490 mutex_exit(&sc->sc_int_lock);
491 rx_avail = dwiic_read(sc, DW_IC_RXFLR);
492 }
493
494 if (rx_avail == 0) {
495 device_printf(sc->sc_dev,
496 "timed out reading remaining %d\n",
497 (int)(len - 1 - readpos));
498 sc->sc_i2c_xfer.error = 1;
499 return (1);
500 }
501
502 DPRINTF(("%s: %s: %d avail to read (%zu remaining)\n",
503 device_xname(sc->sc_dev), __func__, rx_avail,
504 len - readpos));
505
506 while (rx_avail > 0) {
507 resp = dwiic_read(sc, DW_IC_DATA_CMD);
508 if (readpos < len) {
509 bdata[readpos] = resp;
510 readpos++;
511 }
512 rx_avail--;
513 }
514
515 if (readpos >= len)
516 break;
517
518 DPRINTF(("%s: still need to read %d bytes\n",
519 device_xname(sc->sc_dev), (int)(len - readpos)));
520 tx_limit = sc->tx_fifo_depth -
521 dwiic_read(sc, DW_IC_TXFLR);
522 }
523 }
524
525 if (I2C_OP_STOP_P(op) && I2C_OP_WRITE_P(op)) {
526 if (flags & I2C_F_POLL) {
527 /* wait for bus to be idle */
528 for (retries = 100; retries > 0; retries--) {
529 st = dwiic_read(sc, DW_IC_STATUS);
530 if (!(st & DW_IC_STATUS_ACTIVITY))
531 break;
532 DELAY(1000);
533 }
534 if (st & DW_IC_STATUS_ACTIVITY)
535 device_printf(sc->sc_dev, "timed out waiting "
536 "for bus idle\n");
537 } else {
538 mutex_enter(&sc->sc_int_lock);
539 dwiic_read(sc, DW_IC_CLR_INTR);
540 dwiic_write(sc, DW_IC_INTR_MASK,
541 DW_IC_INTR_STOP_DET);
542 if (cv_timedwait(&sc->sc_int_stopwait,
543 &sc->sc_int_lock, hz / 2) != 0)
544 device_printf(sc->sc_dev, "timed out waiting "
545 "for stop intr\n");
546 dwiic_write(sc, DW_IC_INTR_MASK, 0);
547 dwiic_read(sc, DW_IC_CLR_INTR);
548 mutex_exit(&sc->sc_int_lock);
549 }
550 }
551
552 return 0;
553 }
554
555 static uint32_t
556 dwiic_read_clear_intrbits(struct dwiic_softc *sc)
557 {
558 uint32_t stat;
559
560 stat = dwiic_read(sc, DW_IC_INTR_STAT);
561
562 if (stat & DW_IC_INTR_RX_UNDER)
563 dwiic_read(sc, DW_IC_CLR_RX_UNDER);
564 if (stat & DW_IC_INTR_RX_OVER)
565 dwiic_read(sc, DW_IC_CLR_RX_OVER);
566 if (stat & DW_IC_INTR_TX_OVER)
567 dwiic_read(sc, DW_IC_CLR_TX_OVER);
568 if (stat & DW_IC_INTR_RD_REQ)
569 dwiic_read(sc, DW_IC_CLR_RD_REQ);
570 if (stat & DW_IC_INTR_TX_ABRT)
571 dwiic_read(sc, DW_IC_CLR_TX_ABRT);
572 if (stat & DW_IC_INTR_RX_DONE)
573 dwiic_read(sc, DW_IC_CLR_RX_DONE);
574 if (stat & DW_IC_INTR_ACTIVITY)
575 dwiic_read(sc, DW_IC_CLR_ACTIVITY);
576 if (stat & DW_IC_INTR_STOP_DET)
577 dwiic_read(sc, DW_IC_CLR_STOP_DET);
578 if (stat & DW_IC_INTR_START_DET)
579 dwiic_read(sc, DW_IC_CLR_START_DET);
580 if (stat & DW_IC_INTR_GEN_CALL)
581 dwiic_read(sc, DW_IC_CLR_GEN_CALL);
582
583 return stat;
584 }
585
586 int
587 dwiic_intr(void *arg)
588 {
589 struct dwiic_softc *sc = arg;
590 uint32_t en, stat;
591
592 /*
593 * Give up if attach hasn't succeeded. If it failed, nothing
594 * to do here. If it is still ongoing and simply hasn't yet
595 * succeeded, interrupts from the device are masked -- so this
596 * interrupt must be shared with another driver -- and any
597 * interrupts applicable to us will be delivered once
598 * interrupts from the device are unmasked in dwiic_i2c_exec.
599 */
600 if (!atomic_load_acquire(&sc->sc_attached))
601 return 0;
602
603 en = dwiic_read(sc, DW_IC_ENABLE);
604 /* probably for the other controller */
605 if (!en)
606 return 0;
607
608 stat = dwiic_read_clear_intrbits(sc);
609 DPRINTF(("%s: %s: enabled=0x%x stat=0x%x\n", device_xname(sc->sc_dev),
610 __func__, en, stat));
611 if (!(stat & ~DW_IC_INTR_ACTIVITY))
612 return 1;
613
614 if (stat & DW_IC_INTR_TX_ABRT)
615 sc->sc_i2c_xfer.error = 1;
616
617 if (sc->sc_i2c_xfer.flags & I2C_F_POLL)
618 DPRINTF(("%s: %s: intr in poll mode?\n", device_xname(sc->sc_dev),
619 __func__));
620 else {
621 mutex_enter(&sc->sc_int_lock);
622 if (stat & DW_IC_INTR_RX_FULL) {
623 dwiic_write(sc, DW_IC_INTR_MASK, 0);
624 DPRINTF(("%s: %s: waking up reader\n",
625 device_xname(sc->sc_dev), __func__));
626 cv_signal(&sc->sc_int_readwait);
627 }
628 if (stat & DW_IC_INTR_TX_EMPTY) {
629 dwiic_write(sc, DW_IC_INTR_MASK, 0);
630 DPRINTF(("%s: %s: waking up writer\n",
631 device_xname(sc->sc_dev), __func__));
632 cv_signal(&sc->sc_int_writewait);
633 }
634 if (stat & DW_IC_INTR_STOP_DET) {
635 dwiic_write(sc, DW_IC_INTR_MASK, 0);
636 DPRINTF(("%s: %s: waking up stopper\n",
637 device_xname(sc->sc_dev), __func__));
638 cv_signal(&sc->sc_int_stopwait);
639 }
640 mutex_exit(&sc->sc_int_lock);
641 }
642
643 return 1;
644 }
645