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