1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 // Copyright(c) 2015-17 Intel Corporation.
3
4 #include <linux/acpi.h>
5 #include <linux/mod_devicetable.h>
6 #include <linux/pm_runtime.h>
7 #include <linux/soundwire/sdw_registers.h>
8 #include <linux/soundwire/sdw.h>
9 #include "bus.h"
10
11 /**
12 * sdw_add_bus_master() - add a bus Master instance
13 * @bus: bus instance
14 *
15 * Initializes the bus instance, read properties and create child
16 * devices.
17 */
sdw_add_bus_master(struct sdw_bus * bus)18 int sdw_add_bus_master(struct sdw_bus *bus)
19 {
20 struct sdw_master_prop *prop = NULL;
21 int ret;
22
23 if (!bus->dev) {
24 pr_err("SoundWire bus has no device\n");
25 return -ENODEV;
26 }
27
28 if (!bus->ops) {
29 dev_err(bus->dev, "SoundWire Bus ops are not set\n");
30 return -EINVAL;
31 }
32
33 mutex_init(&bus->msg_lock);
34 mutex_init(&bus->bus_lock);
35 INIT_LIST_HEAD(&bus->slaves);
36 INIT_LIST_HEAD(&bus->m_rt_list);
37
38 /*
39 * Initialize multi_link flag
40 * TODO: populate this flag by reading property from FW node
41 */
42 bus->multi_link = false;
43 if (bus->ops->read_prop) {
44 ret = bus->ops->read_prop(bus);
45 if (ret < 0) {
46 dev_err(bus->dev,
47 "Bus read properties failed:%d\n", ret);
48 return ret;
49 }
50 }
51
52 sdw_bus_debugfs_init(bus);
53
54 /*
55 * Device numbers in SoundWire are 0 through 15. Enumeration device
56 * number (0), Broadcast device number (15), Group numbers (12 and
57 * 13) and Master device number (14) are not used for assignment so
58 * mask these and other higher bits.
59 */
60
61 /* Set higher order bits */
62 *bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
63
64 /* Set enumuration device number and broadcast device number */
65 set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
66 set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
67
68 /* Set group device numbers and master device number */
69 set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
70 set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
71 set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
72
73 /*
74 * SDW is an enumerable bus, but devices can be powered off. So,
75 * they won't be able to report as present.
76 *
77 * Create Slave devices based on Slaves described in
78 * the respective firmware (ACPI/DT)
79 */
80 if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
81 ret = sdw_acpi_find_slaves(bus);
82 else if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node)
83 ret = sdw_of_find_slaves(bus);
84 else
85 ret = -ENOTSUPP; /* No ACPI/DT so error out */
86
87 if (ret) {
88 dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
89 return ret;
90 }
91
92 /*
93 * Initialize clock values based on Master properties. The max
94 * frequency is read from max_clk_freq property. Current assumption
95 * is that the bus will start at highest clock frequency when
96 * powered on.
97 *
98 * Default active bank will be 0 as out of reset the Slaves have
99 * to start with bank 0 (Table 40 of Spec)
100 */
101 prop = &bus->prop;
102 bus->params.max_dr_freq = prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR;
103 bus->params.curr_dr_freq = bus->params.max_dr_freq;
104 bus->params.curr_bank = SDW_BANK0;
105 bus->params.next_bank = SDW_BANK1;
106
107 return 0;
108 }
109 EXPORT_SYMBOL(sdw_add_bus_master);
110
sdw_delete_slave(struct device * dev,void * data)111 static int sdw_delete_slave(struct device *dev, void *data)
112 {
113 struct sdw_slave *slave = dev_to_sdw_dev(dev);
114 struct sdw_bus *bus = slave->bus;
115
116 sdw_slave_debugfs_exit(slave);
117
118 mutex_lock(&bus->bus_lock);
119
120 if (slave->dev_num) /* clear dev_num if assigned */
121 clear_bit(slave->dev_num, bus->assigned);
122
123 list_del_init(&slave->node);
124 mutex_unlock(&bus->bus_lock);
125
126 device_unregister(dev);
127 return 0;
128 }
129
130 /**
131 * sdw_delete_bus_master() - delete the bus master instance
132 * @bus: bus to be deleted
133 *
134 * Remove the instance, delete the child devices.
135 */
sdw_delete_bus_master(struct sdw_bus * bus)136 void sdw_delete_bus_master(struct sdw_bus *bus)
137 {
138 device_for_each_child(bus->dev, NULL, sdw_delete_slave);
139
140 sdw_bus_debugfs_exit(bus);
141 }
142 EXPORT_SYMBOL(sdw_delete_bus_master);
143
144 /*
145 * SDW IO Calls
146 */
147
find_response_code(enum sdw_command_response resp)148 static inline int find_response_code(enum sdw_command_response resp)
149 {
150 switch (resp) {
151 case SDW_CMD_OK:
152 return 0;
153
154 case SDW_CMD_IGNORED:
155 return -ENODATA;
156
157 case SDW_CMD_TIMEOUT:
158 return -ETIMEDOUT;
159
160 default:
161 return -EIO;
162 }
163 }
164
do_transfer(struct sdw_bus * bus,struct sdw_msg * msg)165 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
166 {
167 int retry = bus->prop.err_threshold;
168 enum sdw_command_response resp;
169 int ret = 0, i;
170
171 for (i = 0; i <= retry; i++) {
172 resp = bus->ops->xfer_msg(bus, msg);
173 ret = find_response_code(resp);
174
175 /* if cmd is ok or ignored return */
176 if (ret == 0 || ret == -ENODATA)
177 return ret;
178 }
179
180 return ret;
181 }
182
do_transfer_defer(struct sdw_bus * bus,struct sdw_msg * msg,struct sdw_defer * defer)183 static inline int do_transfer_defer(struct sdw_bus *bus,
184 struct sdw_msg *msg,
185 struct sdw_defer *defer)
186 {
187 int retry = bus->prop.err_threshold;
188 enum sdw_command_response resp;
189 int ret = 0, i;
190
191 defer->msg = msg;
192 defer->length = msg->len;
193 init_completion(&defer->complete);
194
195 for (i = 0; i <= retry; i++) {
196 resp = bus->ops->xfer_msg_defer(bus, msg, defer);
197 ret = find_response_code(resp);
198 /* if cmd is ok or ignored return */
199 if (ret == 0 || ret == -ENODATA)
200 return ret;
201 }
202
203 return ret;
204 }
205
sdw_reset_page(struct sdw_bus * bus,u16 dev_num)206 static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num)
207 {
208 int retry = bus->prop.err_threshold;
209 enum sdw_command_response resp;
210 int ret = 0, i;
211
212 for (i = 0; i <= retry; i++) {
213 resp = bus->ops->reset_page_addr(bus, dev_num);
214 ret = find_response_code(resp);
215 /* if cmd is ok or ignored return */
216 if (ret == 0 || ret == -ENODATA)
217 return ret;
218 }
219
220 return ret;
221 }
222
223 /**
224 * sdw_transfer() - Synchronous transfer message to a SDW Slave device
225 * @bus: SDW bus
226 * @msg: SDW message to be xfered
227 */
sdw_transfer(struct sdw_bus * bus,struct sdw_msg * msg)228 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
229 {
230 int ret;
231
232 mutex_lock(&bus->msg_lock);
233
234 ret = do_transfer(bus, msg);
235 if (ret != 0 && ret != -ENODATA)
236 dev_err(bus->dev, "trf on Slave %d failed:%d\n",
237 msg->dev_num, ret);
238
239 if (msg->page)
240 sdw_reset_page(bus, msg->dev_num);
241
242 mutex_unlock(&bus->msg_lock);
243
244 return ret;
245 }
246
247 /**
248 * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
249 * @bus: SDW bus
250 * @msg: SDW message to be xfered
251 * @defer: Defer block for signal completion
252 *
253 * Caller needs to hold the msg_lock lock while calling this
254 */
sdw_transfer_defer(struct sdw_bus * bus,struct sdw_msg * msg,struct sdw_defer * defer)255 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
256 struct sdw_defer *defer)
257 {
258 int ret;
259
260 if (!bus->ops->xfer_msg_defer)
261 return -ENOTSUPP;
262
263 ret = do_transfer_defer(bus, msg, defer);
264 if (ret != 0 && ret != -ENODATA)
265 dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n",
266 msg->dev_num, ret);
267
268 if (msg->page)
269 sdw_reset_page(bus, msg->dev_num);
270
271 return ret;
272 }
273
sdw_fill_msg(struct sdw_msg * msg,struct sdw_slave * slave,u32 addr,size_t count,u16 dev_num,u8 flags,u8 * buf)274 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
275 u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf)
276 {
277 memset(msg, 0, sizeof(*msg));
278 msg->addr = addr; /* addr is 16 bit and truncated here */
279 msg->len = count;
280 msg->dev_num = dev_num;
281 msg->flags = flags;
282 msg->buf = buf;
283
284 if (addr < SDW_REG_NO_PAGE) { /* no paging area */
285 return 0;
286 } else if (addr >= SDW_REG_MAX) { /* illegal addr */
287 pr_err("SDW: Invalid address %x passed\n", addr);
288 return -EINVAL;
289 }
290
291 if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */
292 if (slave && !slave->prop.paging_support)
293 return 0;
294 /* no need for else as that will fall-through to paging */
295 }
296
297 /* paging mandatory */
298 if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) {
299 pr_err("SDW: Invalid device for paging :%d\n", dev_num);
300 return -EINVAL;
301 }
302
303 if (!slave) {
304 pr_err("SDW: No slave for paging addr\n");
305 return -EINVAL;
306 } else if (!slave->prop.paging_support) {
307 dev_err(&slave->dev,
308 "address %x needs paging but no support\n", addr);
309 return -EINVAL;
310 }
311
312 msg->addr_page1 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE1_MASK));
313 msg->addr_page2 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE2_MASK));
314 msg->addr |= BIT(15);
315 msg->page = true;
316
317 return 0;
318 }
319
320 /**
321 * sdw_nread() - Read "n" contiguous SDW Slave registers
322 * @slave: SDW Slave
323 * @addr: Register address
324 * @count: length
325 * @val: Buffer for values to be read
326 */
sdw_nread(struct sdw_slave * slave,u32 addr,size_t count,u8 * val)327 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
328 {
329 struct sdw_msg msg;
330 int ret;
331
332 ret = sdw_fill_msg(&msg, slave, addr, count,
333 slave->dev_num, SDW_MSG_FLAG_READ, val);
334 if (ret < 0)
335 return ret;
336
337 ret = pm_runtime_get_sync(slave->bus->dev);
338 if (ret < 0)
339 return ret;
340
341 ret = sdw_transfer(slave->bus, &msg);
342 pm_runtime_put(slave->bus->dev);
343
344 return ret;
345 }
346 EXPORT_SYMBOL(sdw_nread);
347
348 /**
349 * sdw_nwrite() - Write "n" contiguous SDW Slave registers
350 * @slave: SDW Slave
351 * @addr: Register address
352 * @count: length
353 * @val: Buffer for values to be read
354 */
sdw_nwrite(struct sdw_slave * slave,u32 addr,size_t count,u8 * val)355 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
356 {
357 struct sdw_msg msg;
358 int ret;
359
360 ret = sdw_fill_msg(&msg, slave, addr, count,
361 slave->dev_num, SDW_MSG_FLAG_WRITE, val);
362 if (ret < 0)
363 return ret;
364
365 ret = pm_runtime_get_sync(slave->bus->dev);
366 if (ret < 0)
367 return ret;
368
369 ret = sdw_transfer(slave->bus, &msg);
370 pm_runtime_put(slave->bus->dev);
371
372 return ret;
373 }
374 EXPORT_SYMBOL(sdw_nwrite);
375
376 /**
377 * sdw_read() - Read a SDW Slave register
378 * @slave: SDW Slave
379 * @addr: Register address
380 */
sdw_read(struct sdw_slave * slave,u32 addr)381 int sdw_read(struct sdw_slave *slave, u32 addr)
382 {
383 u8 buf;
384 int ret;
385
386 ret = sdw_nread(slave, addr, 1, &buf);
387 if (ret < 0)
388 return ret;
389 else
390 return buf;
391 }
392 EXPORT_SYMBOL(sdw_read);
393
394 /**
395 * sdw_write() - Write a SDW Slave register
396 * @slave: SDW Slave
397 * @addr: Register address
398 * @value: Register value
399 */
sdw_write(struct sdw_slave * slave,u32 addr,u8 value)400 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)
401 {
402 return sdw_nwrite(slave, addr, 1, &value);
403 }
404 EXPORT_SYMBOL(sdw_write);
405
406 /*
407 * SDW alert handling
408 */
409
410 /* called with bus_lock held */
sdw_get_slave(struct sdw_bus * bus,int i)411 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
412 {
413 struct sdw_slave *slave = NULL;
414
415 list_for_each_entry(slave, &bus->slaves, node) {
416 if (slave->dev_num == i)
417 return slave;
418 }
419
420 return NULL;
421 }
422
sdw_compare_devid(struct sdw_slave * slave,struct sdw_slave_id id)423 static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
424 {
425 if (slave->id.unique_id != id.unique_id ||
426 slave->id.mfg_id != id.mfg_id ||
427 slave->id.part_id != id.part_id ||
428 slave->id.class_id != id.class_id)
429 return -ENODEV;
430
431 return 0;
432 }
433
434 /* called with bus_lock held */
sdw_get_device_num(struct sdw_slave * slave)435 static int sdw_get_device_num(struct sdw_slave *slave)
436 {
437 int bit;
438
439 bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
440 if (bit == SDW_MAX_DEVICES) {
441 bit = -ENODEV;
442 goto err;
443 }
444
445 /*
446 * Do not update dev_num in Slave data structure here,
447 * Update once program dev_num is successful
448 */
449 set_bit(bit, slave->bus->assigned);
450
451 err:
452 return bit;
453 }
454
sdw_assign_device_num(struct sdw_slave * slave)455 static int sdw_assign_device_num(struct sdw_slave *slave)
456 {
457 int ret, dev_num;
458
459 /* check first if device number is assigned, if so reuse that */
460 if (!slave->dev_num) {
461 mutex_lock(&slave->bus->bus_lock);
462 dev_num = sdw_get_device_num(slave);
463 mutex_unlock(&slave->bus->bus_lock);
464 if (dev_num < 0) {
465 dev_err(slave->bus->dev, "Get dev_num failed: %d\n",
466 dev_num);
467 return dev_num;
468 }
469 } else {
470 dev_info(slave->bus->dev,
471 "Slave already registered dev_num:%d\n",
472 slave->dev_num);
473
474 /* Clear the slave->dev_num to transfer message on device 0 */
475 dev_num = slave->dev_num;
476 slave->dev_num = 0;
477 }
478
479 ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num);
480 if (ret < 0) {
481 dev_err(&slave->dev, "Program device_num %d failed: %d\n",
482 dev_num, ret);
483 return ret;
484 }
485
486 /* After xfer of msg, restore dev_num */
487 slave->dev_num = dev_num;
488
489 return 0;
490 }
491
sdw_extract_slave_id(struct sdw_bus * bus,u64 addr,struct sdw_slave_id * id)492 void sdw_extract_slave_id(struct sdw_bus *bus,
493 u64 addr, struct sdw_slave_id *id)
494 {
495 dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
496
497 /*
498 * Spec definition
499 * Register Bit Contents
500 * DevId_0 [7:4] 47:44 sdw_version
501 * DevId_0 [3:0] 43:40 unique_id
502 * DevId_1 39:32 mfg_id [15:8]
503 * DevId_2 31:24 mfg_id [7:0]
504 * DevId_3 23:16 part_id [15:8]
505 * DevId_4 15:08 part_id [7:0]
506 * DevId_5 07:00 class_id
507 */
508 id->sdw_version = (addr >> 44) & GENMASK(3, 0);
509 id->unique_id = (addr >> 40) & GENMASK(3, 0);
510 id->mfg_id = (addr >> 24) & GENMASK(15, 0);
511 id->part_id = (addr >> 8) & GENMASK(15, 0);
512 id->class_id = addr & GENMASK(7, 0);
513
514 dev_dbg(bus->dev,
515 "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x\n",
516 id->class_id, id->part_id, id->mfg_id,
517 id->unique_id, id->sdw_version);
518 }
519
sdw_program_device_num(struct sdw_bus * bus)520 static int sdw_program_device_num(struct sdw_bus *bus)
521 {
522 u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
523 struct sdw_slave *slave, *_s;
524 struct sdw_slave_id id;
525 struct sdw_msg msg;
526 bool found = false;
527 int count = 0, ret;
528 u64 addr;
529
530 /* No Slave, so use raw xfer api */
531 ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
532 SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
533 if (ret < 0)
534 return ret;
535
536 do {
537 ret = sdw_transfer(bus, &msg);
538 if (ret == -ENODATA) { /* end of device id reads */
539 dev_dbg(bus->dev, "No more devices to enumerate\n");
540 ret = 0;
541 break;
542 }
543 if (ret < 0) {
544 dev_err(bus->dev, "DEVID read fail:%d\n", ret);
545 break;
546 }
547
548 /*
549 * Construct the addr and extract. Cast the higher shift
550 * bits to avoid truncation due to size limit.
551 */
552 addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
553 ((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
554 ((u64)buf[0] << 40);
555
556 sdw_extract_slave_id(bus, addr, &id);
557
558 /* Now compare with entries */
559 list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
560 if (sdw_compare_devid(slave, id) == 0) {
561 found = true;
562
563 /*
564 * Assign a new dev_num to this Slave and
565 * not mark it present. It will be marked
566 * present after it reports ATTACHED on new
567 * dev_num
568 */
569 ret = sdw_assign_device_num(slave);
570 if (ret) {
571 dev_err(slave->bus->dev,
572 "Assign dev_num failed:%d\n",
573 ret);
574 return ret;
575 }
576
577 break;
578 }
579 }
580
581 if (!found) {
582 /* TODO: Park this device in Group 13 */
583 dev_err(bus->dev, "Slave Entry not found\n");
584 }
585
586 count++;
587
588 /*
589 * Check till error out or retry (count) exhausts.
590 * Device can drop off and rejoin during enumeration
591 * so count till twice the bound.
592 */
593
594 } while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
595
596 return ret;
597 }
598
sdw_modify_slave_status(struct sdw_slave * slave,enum sdw_slave_status status)599 static void sdw_modify_slave_status(struct sdw_slave *slave,
600 enum sdw_slave_status status)
601 {
602 mutex_lock(&slave->bus->bus_lock);
603 slave->status = status;
604 mutex_unlock(&slave->bus->bus_lock);
605 }
606
sdw_configure_dpn_intr(struct sdw_slave * slave,int port,bool enable,int mask)607 int sdw_configure_dpn_intr(struct sdw_slave *slave,
608 int port, bool enable, int mask)
609 {
610 u32 addr;
611 int ret;
612 u8 val = 0;
613
614 addr = SDW_DPN_INTMASK(port);
615
616 /* Set/Clear port ready interrupt mask */
617 if (enable) {
618 val |= mask;
619 val |= SDW_DPN_INT_PORT_READY;
620 } else {
621 val &= ~(mask);
622 val &= ~SDW_DPN_INT_PORT_READY;
623 }
624
625 ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
626 if (ret < 0)
627 dev_err(slave->bus->dev,
628 "SDW_DPN_INTMASK write failed:%d\n", val);
629
630 return ret;
631 }
632
sdw_initialize_slave(struct sdw_slave * slave)633 static int sdw_initialize_slave(struct sdw_slave *slave)
634 {
635 struct sdw_slave_prop *prop = &slave->prop;
636 int ret;
637 u8 val;
638
639 /*
640 * Set bus clash, parity and SCP implementation
641 * defined interrupt mask
642 * TODO: Read implementation defined interrupt mask
643 * from Slave property
644 */
645 val = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH |
646 SDW_SCP_INT1_PARITY;
647
648 /* Enable SCP interrupts */
649 ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val);
650 if (ret < 0) {
651 dev_err(slave->bus->dev,
652 "SDW_SCP_INTMASK1 write failed:%d\n", ret);
653 return ret;
654 }
655
656 /* No need to continue if DP0 is not present */
657 if (!slave->prop.dp0_prop)
658 return 0;
659
660 /* Enable DP0 interrupts */
661 val = prop->dp0_prop->imp_def_interrupts;
662 val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
663
664 ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
665 if (ret < 0) {
666 dev_err(slave->bus->dev,
667 "SDW_DP0_INTMASK read failed:%d\n", ret);
668 return val;
669 }
670
671 return 0;
672 }
673
sdw_handle_dp0_interrupt(struct sdw_slave * slave,u8 * slave_status)674 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
675 {
676 u8 clear = 0, impl_int_mask;
677 int status, status2, ret, count = 0;
678
679 status = sdw_read(slave, SDW_DP0_INT);
680 if (status < 0) {
681 dev_err(slave->bus->dev,
682 "SDW_DP0_INT read failed:%d\n", status);
683 return status;
684 }
685
686 do {
687 if (status & SDW_DP0_INT_TEST_FAIL) {
688 dev_err(&slave->dev, "Test fail for port 0\n");
689 clear |= SDW_DP0_INT_TEST_FAIL;
690 }
691
692 /*
693 * Assumption: PORT_READY interrupt will be received only for
694 * ports implementing Channel Prepare state machine (CP_SM)
695 */
696
697 if (status & SDW_DP0_INT_PORT_READY) {
698 complete(&slave->port_ready[0]);
699 clear |= SDW_DP0_INT_PORT_READY;
700 }
701
702 if (status & SDW_DP0_INT_BRA_FAILURE) {
703 dev_err(&slave->dev, "BRA failed\n");
704 clear |= SDW_DP0_INT_BRA_FAILURE;
705 }
706
707 impl_int_mask = SDW_DP0_INT_IMPDEF1 |
708 SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
709
710 if (status & impl_int_mask) {
711 clear |= impl_int_mask;
712 *slave_status = clear;
713 }
714
715 /* clear the interrupt */
716 ret = sdw_write(slave, SDW_DP0_INT, clear);
717 if (ret < 0) {
718 dev_err(slave->bus->dev,
719 "SDW_DP0_INT write failed:%d\n", ret);
720 return ret;
721 }
722
723 /* Read DP0 interrupt again */
724 status2 = sdw_read(slave, SDW_DP0_INT);
725 if (status2 < 0) {
726 dev_err(slave->bus->dev,
727 "SDW_DP0_INT read failed:%d\n", status2);
728 return status2;
729 }
730 status &= status2;
731
732 count++;
733
734 /* we can get alerts while processing so keep retrying */
735 } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
736
737 if (count == SDW_READ_INTR_CLEAR_RETRY)
738 dev_warn(slave->bus->dev, "Reached MAX_RETRY on DP0 read\n");
739
740 return ret;
741 }
742
sdw_handle_port_interrupt(struct sdw_slave * slave,int port,u8 * slave_status)743 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
744 int port, u8 *slave_status)
745 {
746 u8 clear = 0, impl_int_mask;
747 int status, status2, ret, count = 0;
748 u32 addr;
749
750 if (port == 0)
751 return sdw_handle_dp0_interrupt(slave, slave_status);
752
753 addr = SDW_DPN_INT(port);
754 status = sdw_read(slave, addr);
755 if (status < 0) {
756 dev_err(slave->bus->dev,
757 "SDW_DPN_INT read failed:%d\n", status);
758
759 return status;
760 }
761
762 do {
763 if (status & SDW_DPN_INT_TEST_FAIL) {
764 dev_err(&slave->dev, "Test fail for port:%d\n", port);
765 clear |= SDW_DPN_INT_TEST_FAIL;
766 }
767
768 /*
769 * Assumption: PORT_READY interrupt will be received only
770 * for ports implementing CP_SM.
771 */
772 if (status & SDW_DPN_INT_PORT_READY) {
773 complete(&slave->port_ready[port]);
774 clear |= SDW_DPN_INT_PORT_READY;
775 }
776
777 impl_int_mask = SDW_DPN_INT_IMPDEF1 |
778 SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
779
780 if (status & impl_int_mask) {
781 clear |= impl_int_mask;
782 *slave_status = clear;
783 }
784
785 /* clear the interrupt */
786 ret = sdw_write(slave, addr, clear);
787 if (ret < 0) {
788 dev_err(slave->bus->dev,
789 "SDW_DPN_INT write failed:%d\n", ret);
790 return ret;
791 }
792
793 /* Read DPN interrupt again */
794 status2 = sdw_read(slave, addr);
795 if (status2 < 0) {
796 dev_err(slave->bus->dev,
797 "SDW_DPN_INT read failed:%d\n", status2);
798 return status2;
799 }
800 status &= status2;
801
802 count++;
803
804 /* we can get alerts while processing so keep retrying */
805 } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
806
807 if (count == SDW_READ_INTR_CLEAR_RETRY)
808 dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read");
809
810 return ret;
811 }
812
sdw_handle_slave_alerts(struct sdw_slave * slave)813 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
814 {
815 struct sdw_slave_intr_status slave_intr;
816 u8 clear = 0, bit, port_status[15] = {0};
817 int port_num, stat, ret, count = 0;
818 unsigned long port;
819 bool slave_notify = false;
820 u8 buf, buf2[2], _buf, _buf2[2];
821
822 sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
823
824 /* Read Instat 1, Instat 2 and Instat 3 registers */
825 ret = sdw_read(slave, SDW_SCP_INT1);
826 if (ret < 0) {
827 dev_err(slave->bus->dev,
828 "SDW_SCP_INT1 read failed:%d\n", ret);
829 return ret;
830 }
831 buf = ret;
832
833 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
834 if (ret < 0) {
835 dev_err(slave->bus->dev,
836 "SDW_SCP_INT2/3 read failed:%d\n", ret);
837 return ret;
838 }
839
840 do {
841 /*
842 * Check parity, bus clash and Slave (impl defined)
843 * interrupt
844 */
845 if (buf & SDW_SCP_INT1_PARITY) {
846 dev_err(&slave->dev, "Parity error detected\n");
847 clear |= SDW_SCP_INT1_PARITY;
848 }
849
850 if (buf & SDW_SCP_INT1_BUS_CLASH) {
851 dev_err(&slave->dev, "Bus clash error detected\n");
852 clear |= SDW_SCP_INT1_BUS_CLASH;
853 }
854
855 /*
856 * When bus clash or parity errors are detected, such errors
857 * are unlikely to be recoverable errors.
858 * TODO: In such scenario, reset bus. Make this configurable
859 * via sysfs property with bus reset being the default.
860 */
861
862 if (buf & SDW_SCP_INT1_IMPL_DEF) {
863 dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
864 clear |= SDW_SCP_INT1_IMPL_DEF;
865 slave_notify = true;
866 }
867
868 /* Check port 0 - 3 interrupts */
869 port = buf & SDW_SCP_INT1_PORT0_3;
870
871 /* To get port number corresponding to bits, shift it */
872 port = port >> SDW_REG_SHIFT(SDW_SCP_INT1_PORT0_3);
873 for_each_set_bit(bit, &port, 8) {
874 sdw_handle_port_interrupt(slave, bit,
875 &port_status[bit]);
876 }
877
878 /* Check if cascade 2 interrupt is present */
879 if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
880 port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
881 for_each_set_bit(bit, &port, 8) {
882 /* scp2 ports start from 4 */
883 port_num = bit + 3;
884 sdw_handle_port_interrupt(slave,
885 port_num,
886 &port_status[port_num]);
887 }
888 }
889
890 /* now check last cascade */
891 if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
892 port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
893 for_each_set_bit(bit, &port, 8) {
894 /* scp3 ports start from 11 */
895 port_num = bit + 10;
896 sdw_handle_port_interrupt(slave,
897 port_num,
898 &port_status[port_num]);
899 }
900 }
901
902 /* Update the Slave driver */
903 if (slave_notify && slave->ops &&
904 slave->ops->interrupt_callback) {
905 slave_intr.control_port = clear;
906 memcpy(slave_intr.port, &port_status,
907 sizeof(slave_intr.port));
908
909 slave->ops->interrupt_callback(slave, &slave_intr);
910 }
911
912 /* Ack interrupt */
913 ret = sdw_write(slave, SDW_SCP_INT1, clear);
914 if (ret < 0) {
915 dev_err(slave->bus->dev,
916 "SDW_SCP_INT1 write failed:%d\n", ret);
917 return ret;
918 }
919
920 /*
921 * Read status again to ensure no new interrupts arrived
922 * while servicing interrupts.
923 */
924 ret = sdw_read(slave, SDW_SCP_INT1);
925 if (ret < 0) {
926 dev_err(slave->bus->dev,
927 "SDW_SCP_INT1 read failed:%d\n", ret);
928 return ret;
929 }
930 _buf = ret;
931
932 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
933 if (ret < 0) {
934 dev_err(slave->bus->dev,
935 "SDW_SCP_INT2/3 read failed:%d\n", ret);
936 return ret;
937 }
938
939 /* Make sure no interrupts are pending */
940 buf &= _buf;
941 buf2[0] &= _buf2[0];
942 buf2[1] &= _buf2[1];
943 stat = buf || buf2[0] || buf2[1];
944
945 /*
946 * Exit loop if Slave is continuously in ALERT state even
947 * after servicing the interrupt multiple times.
948 */
949 count++;
950
951 /* we can get alerts while processing so keep retrying */
952 } while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
953
954 if (count == SDW_READ_INTR_CLEAR_RETRY)
955 dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read\n");
956
957 return ret;
958 }
959
sdw_update_slave_status(struct sdw_slave * slave,enum sdw_slave_status status)960 static int sdw_update_slave_status(struct sdw_slave *slave,
961 enum sdw_slave_status status)
962 {
963 if (slave->ops && slave->ops->update_status)
964 return slave->ops->update_status(slave, status);
965
966 return 0;
967 }
968
969 /**
970 * sdw_handle_slave_status() - Handle Slave status
971 * @bus: SDW bus instance
972 * @status: Status for all Slave(s)
973 */
sdw_handle_slave_status(struct sdw_bus * bus,enum sdw_slave_status status[])974 int sdw_handle_slave_status(struct sdw_bus *bus,
975 enum sdw_slave_status status[])
976 {
977 enum sdw_slave_status prev_status;
978 struct sdw_slave *slave;
979 int i, ret = 0;
980
981 if (status[0] == SDW_SLAVE_ATTACHED) {
982 dev_dbg(bus->dev, "Slave attached, programming device number\n");
983 ret = sdw_program_device_num(bus);
984 if (ret)
985 dev_err(bus->dev, "Slave attach failed: %d\n", ret);
986 /*
987 * programming a device number will have side effects,
988 * so we deal with other devices at a later time
989 */
990 return ret;
991 }
992
993 /* Continue to check other slave statuses */
994 for (i = 1; i <= SDW_MAX_DEVICES; i++) {
995 mutex_lock(&bus->bus_lock);
996 if (test_bit(i, bus->assigned) == false) {
997 mutex_unlock(&bus->bus_lock);
998 continue;
999 }
1000 mutex_unlock(&bus->bus_lock);
1001
1002 slave = sdw_get_slave(bus, i);
1003 if (!slave)
1004 continue;
1005
1006 switch (status[i]) {
1007 case SDW_SLAVE_UNATTACHED:
1008 if (slave->status == SDW_SLAVE_UNATTACHED)
1009 break;
1010
1011 sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1012 break;
1013
1014 case SDW_SLAVE_ALERT:
1015 ret = sdw_handle_slave_alerts(slave);
1016 if (ret)
1017 dev_err(bus->dev,
1018 "Slave %d alert handling failed: %d\n",
1019 i, ret);
1020 break;
1021
1022 case SDW_SLAVE_ATTACHED:
1023 if (slave->status == SDW_SLAVE_ATTACHED)
1024 break;
1025
1026 prev_status = slave->status;
1027 sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1028
1029 if (prev_status == SDW_SLAVE_ALERT)
1030 break;
1031
1032 ret = sdw_initialize_slave(slave);
1033 if (ret)
1034 dev_err(bus->dev,
1035 "Slave %d initialization failed: %d\n",
1036 i, ret);
1037
1038 break;
1039
1040 default:
1041 dev_err(bus->dev, "Invalid slave %d status:%d\n",
1042 i, status[i]);
1043 break;
1044 }
1045
1046 ret = sdw_update_slave_status(slave, status[i]);
1047 if (ret)
1048 dev_err(slave->bus->dev,
1049 "Update Slave status failed:%d\n", ret);
1050 }
1051
1052 return ret;
1053 }
1054 EXPORT_SYMBOL(sdw_handle_slave_status);
1055