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