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1 | /* |
2 | * Copyright (c) 2015, Sony Mobile Communications AB. | |
3 | * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 and | |
7 | * only version 2 as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/interrupt.h> | |
16 | #include <linux/list.h> | |
17 | #include <linux/io.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/irq.h> | |
20 | #include <linux/irqdomain.h> | |
21 | #include <linux/mfd/syscon.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/regmap.h> | |
25 | #include <linux/soc/qcom/smem.h> | |
26 | #include <linux/soc/qcom/smem_state.h> | |
27 | #include <linux/spinlock.h> | |
28 | ||
29 | /* | |
30 | * The Shared Memory Point to Point (SMP2P) protocol facilitates communication | |
31 | * of a single 32-bit value between two processors. Each value has a single | |
32 | * writer (the local side) and a single reader (the remote side). Values are | |
33 | * uniquely identified in the system by the directed edge (local processor ID | |
34 | * to remote processor ID) and a string identifier. | |
35 | * | |
36 | * Each processor is responsible for creating the outgoing SMEM items and each | |
37 | * item is writable by the local processor and readable by the remote | |
38 | * processor. By using two separate SMEM items that are single-reader and | |
39 | * single-writer, SMP2P does not require any remote locking mechanisms. | |
40 | * | |
41 | * The driver uses the Linux GPIO and interrupt framework to expose a virtual | |
42 | * GPIO for each outbound entry and a virtual interrupt controller for each | |
43 | * inbound entry. | |
44 | */ | |
45 | ||
46 | #define SMP2P_MAX_ENTRY 16 | |
47 | #define SMP2P_MAX_ENTRY_NAME 16 | |
48 | ||
49 | #define SMP2P_FEATURE_SSR_ACK 0x1 | |
50 | ||
51 | #define SMP2P_MAGIC 0x504d5324 | |
52 | ||
53 | /** | |
54 | * struct smp2p_smem_item - in memory communication structure | |
55 | * @magic: magic number | |
56 | * @version: version - must be 1 | |
57 | * @features: features flag - currently unused | |
58 | * @local_pid: processor id of sending end | |
59 | * @remote_pid: processor id of receiving end | |
60 | * @total_entries: number of entries - always SMP2P_MAX_ENTRY | |
61 | * @valid_entries: number of allocated entries | |
62 | * @flags: | |
63 | * @entries: individual communication entries | |
64 | * @name: name of the entry | |
65 | * @value: content of the entry | |
66 | */ | |
67 | struct smp2p_smem_item { | |
68 | u32 magic; | |
69 | u8 version; | |
70 | unsigned features:24; | |
71 | u16 local_pid; | |
72 | u16 remote_pid; | |
73 | u16 total_entries; | |
74 | u16 valid_entries; | |
75 | u32 flags; | |
76 | ||
77 | struct { | |
78 | u8 name[SMP2P_MAX_ENTRY_NAME]; | |
79 | u32 value; | |
80 | } entries[SMP2P_MAX_ENTRY]; | |
81 | } __packed; | |
82 | ||
83 | /** | |
84 | * struct smp2p_entry - driver context matching one entry | |
85 | * @node: list entry to keep track of allocated entries | |
86 | * @smp2p: reference to the device driver context | |
87 | * @name: name of the entry, to match against smp2p_smem_item | |
88 | * @value: pointer to smp2p_smem_item entry value | |
89 | * @last_value: last handled value | |
90 | * @domain: irq_domain for inbound entries | |
91 | * @irq_enabled:bitmap to track enabled irq bits | |
92 | * @irq_rising: bitmap to mark irq bits for rising detection | |
93 | * @irq_falling:bitmap to mark irq bits for falling detection | |
94 | * @state: smem state handle | |
95 | * @lock: spinlock to protect read-modify-write of the value | |
96 | */ | |
97 | struct smp2p_entry { | |
98 | struct list_head node; | |
99 | struct qcom_smp2p *smp2p; | |
100 | ||
101 | const char *name; | |
102 | u32 *value; | |
103 | u32 last_value; | |
104 | ||
105 | struct irq_domain *domain; | |
106 | DECLARE_BITMAP(irq_enabled, 32); | |
107 | DECLARE_BITMAP(irq_rising, 32); | |
108 | DECLARE_BITMAP(irq_falling, 32); | |
109 | ||
110 | struct qcom_smem_state *state; | |
111 | ||
112 | spinlock_t lock; | |
113 | }; | |
114 | ||
115 | #define SMP2P_INBOUND 0 | |
116 | #define SMP2P_OUTBOUND 1 | |
117 | ||
118 | /** | |
119 | * struct qcom_smp2p - device driver context | |
120 | * @dev: device driver handle | |
121 | * @in: pointer to the inbound smem item | |
122 | * @smem_items: ids of the two smem items | |
123 | * @valid_entries: already scanned inbound entries | |
124 | * @local_pid: processor id of the inbound edge | |
125 | * @remote_pid: processor id of the outbound edge | |
126 | * @ipc_regmap: regmap for the outbound ipc | |
127 | * @ipc_offset: offset within the regmap | |
128 | * @ipc_bit: bit in regmap@offset to kick to signal remote processor | |
129 | * @inbound: list of inbound entries | |
130 | * @outbound: list of outbound entries | |
131 | */ | |
132 | struct qcom_smp2p { | |
133 | struct device *dev; | |
134 | ||
135 | struct smp2p_smem_item *in; | |
136 | struct smp2p_smem_item *out; | |
137 | ||
138 | unsigned smem_items[SMP2P_OUTBOUND + 1]; | |
139 | ||
140 | unsigned valid_entries; | |
141 | ||
142 | unsigned local_pid; | |
143 | unsigned remote_pid; | |
144 | ||
145 | struct regmap *ipc_regmap; | |
146 | int ipc_offset; | |
147 | int ipc_bit; | |
148 | ||
149 | struct list_head inbound; | |
150 | struct list_head outbound; | |
151 | }; | |
152 | ||
153 | static void qcom_smp2p_kick(struct qcom_smp2p *smp2p) | |
154 | { | |
155 | /* Make sure any updated data is written before the kick */ | |
156 | wmb(); | |
157 | regmap_write(smp2p->ipc_regmap, smp2p->ipc_offset, BIT(smp2p->ipc_bit)); | |
158 | } | |
159 | ||
160 | /** | |
161 | * qcom_smp2p_intr() - interrupt handler for incoming notifications | |
162 | * @irq: unused | |
163 | * @data: smp2p driver context | |
164 | * | |
165 | * Handle notifications from the remote side to handle newly allocated entries | |
166 | * or any changes to the state bits of existing entries. | |
167 | */ | |
168 | static irqreturn_t qcom_smp2p_intr(int irq, void *data) | |
169 | { | |
170 | struct smp2p_smem_item *in; | |
171 | struct smp2p_entry *entry; | |
172 | struct qcom_smp2p *smp2p = data; | |
173 | unsigned smem_id = smp2p->smem_items[SMP2P_INBOUND]; | |
174 | unsigned pid = smp2p->remote_pid; | |
175 | size_t size; | |
176 | int irq_pin; | |
177 | u32 status; | |
178 | char buf[SMP2P_MAX_ENTRY_NAME]; | |
179 | u32 val; | |
180 | int i; | |
181 | ||
182 | in = smp2p->in; | |
183 | ||
184 | /* Acquire smem item, if not already found */ | |
185 | if (!in) { | |
186 | in = qcom_smem_get(pid, smem_id, &size); | |
187 | if (IS_ERR(in)) { | |
188 | dev_err(smp2p->dev, | |
189 | "Unable to acquire remote smp2p item\n"); | |
190 | return IRQ_HANDLED; | |
191 | } | |
192 | ||
193 | smp2p->in = in; | |
194 | } | |
195 | ||
196 | /* Match newly created entries */ | |
197 | for (i = smp2p->valid_entries; i < in->valid_entries; i++) { | |
198 | list_for_each_entry(entry, &smp2p->inbound, node) { | |
e7306dd7 | 199 | memcpy(buf, in->entries[i].name, sizeof(buf)); |
50e99641 BA |
200 | if (!strcmp(buf, entry->name)) { |
201 | entry->value = &in->entries[i].value; | |
202 | break; | |
203 | } | |
204 | } | |
205 | } | |
206 | smp2p->valid_entries = i; | |
207 | ||
208 | /* Fire interrupts based on any value changes */ | |
209 | list_for_each_entry(entry, &smp2p->inbound, node) { | |
210 | /* Ignore entries not yet allocated by the remote side */ | |
211 | if (!entry->value) | |
212 | continue; | |
213 | ||
214 | val = readl(entry->value); | |
215 | ||
216 | status = val ^ entry->last_value; | |
217 | entry->last_value = val; | |
218 | ||
219 | /* No changes of this entry? */ | |
220 | if (!status) | |
221 | continue; | |
222 | ||
223 | for_each_set_bit(i, entry->irq_enabled, 32) { | |
224 | if (!(status & BIT(i))) | |
225 | continue; | |
226 | ||
227 | if ((val & BIT(i) && test_bit(i, entry->irq_rising)) || | |
228 | (!(val & BIT(i)) && test_bit(i, entry->irq_falling))) { | |
229 | irq_pin = irq_find_mapping(entry->domain, i); | |
230 | handle_nested_irq(irq_pin); | |
231 | } | |
232 | } | |
233 | } | |
234 | ||
235 | return IRQ_HANDLED; | |
236 | } | |
237 | ||
238 | static void smp2p_mask_irq(struct irq_data *irqd) | |
239 | { | |
240 | struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd); | |
241 | irq_hw_number_t irq = irqd_to_hwirq(irqd); | |
242 | ||
243 | clear_bit(irq, entry->irq_enabled); | |
244 | } | |
245 | ||
246 | static void smp2p_unmask_irq(struct irq_data *irqd) | |
247 | { | |
248 | struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd); | |
249 | irq_hw_number_t irq = irqd_to_hwirq(irqd); | |
250 | ||
251 | set_bit(irq, entry->irq_enabled); | |
252 | } | |
253 | ||
254 | static int smp2p_set_irq_type(struct irq_data *irqd, unsigned int type) | |
255 | { | |
256 | struct smp2p_entry *entry = irq_data_get_irq_chip_data(irqd); | |
257 | irq_hw_number_t irq = irqd_to_hwirq(irqd); | |
258 | ||
259 | if (!(type & IRQ_TYPE_EDGE_BOTH)) | |
260 | return -EINVAL; | |
261 | ||
262 | if (type & IRQ_TYPE_EDGE_RISING) | |
263 | set_bit(irq, entry->irq_rising); | |
264 | else | |
265 | clear_bit(irq, entry->irq_rising); | |
266 | ||
267 | if (type & IRQ_TYPE_EDGE_FALLING) | |
268 | set_bit(irq, entry->irq_falling); | |
269 | else | |
270 | clear_bit(irq, entry->irq_falling); | |
271 | ||
272 | return 0; | |
273 | } | |
274 | ||
275 | static struct irq_chip smp2p_irq_chip = { | |
276 | .name = "smp2p", | |
277 | .irq_mask = smp2p_mask_irq, | |
278 | .irq_unmask = smp2p_unmask_irq, | |
279 | .irq_set_type = smp2p_set_irq_type, | |
280 | }; | |
281 | ||
282 | static int smp2p_irq_map(struct irq_domain *d, | |
283 | unsigned int irq, | |
284 | irq_hw_number_t hw) | |
285 | { | |
286 | struct smp2p_entry *entry = d->host_data; | |
287 | ||
288 | irq_set_chip_and_handler(irq, &smp2p_irq_chip, handle_level_irq); | |
289 | irq_set_chip_data(irq, entry); | |
290 | irq_set_nested_thread(irq, 1); | |
291 | irq_set_noprobe(irq); | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | static const struct irq_domain_ops smp2p_irq_ops = { | |
297 | .map = smp2p_irq_map, | |
298 | .xlate = irq_domain_xlate_twocell, | |
299 | }; | |
300 | ||
301 | static int qcom_smp2p_inbound_entry(struct qcom_smp2p *smp2p, | |
302 | struct smp2p_entry *entry, | |
303 | struct device_node *node) | |
304 | { | |
305 | entry->domain = irq_domain_add_linear(node, 32, &smp2p_irq_ops, entry); | |
306 | if (!entry->domain) { | |
307 | dev_err(smp2p->dev, "failed to add irq_domain\n"); | |
308 | return -ENOMEM; | |
309 | } | |
310 | ||
311 | return 0; | |
312 | } | |
313 | ||
314 | static int smp2p_update_bits(void *data, u32 mask, u32 value) | |
315 | { | |
316 | struct smp2p_entry *entry = data; | |
317 | u32 orig; | |
318 | u32 val; | |
319 | ||
320 | spin_lock(&entry->lock); | |
321 | val = orig = readl(entry->value); | |
322 | val &= ~mask; | |
323 | val |= value; | |
324 | writel(val, entry->value); | |
325 | spin_unlock(&entry->lock); | |
326 | ||
327 | if (val != orig) | |
328 | qcom_smp2p_kick(entry->smp2p); | |
329 | ||
330 | return 0; | |
331 | } | |
332 | ||
333 | static const struct qcom_smem_state_ops smp2p_state_ops = { | |
334 | .update_bits = smp2p_update_bits, | |
335 | }; | |
336 | ||
337 | static int qcom_smp2p_outbound_entry(struct qcom_smp2p *smp2p, | |
338 | struct smp2p_entry *entry, | |
339 | struct device_node *node) | |
340 | { | |
341 | struct smp2p_smem_item *out = smp2p->out; | |
342 | char buf[SMP2P_MAX_ENTRY_NAME] = {}; | |
343 | ||
344 | /* Allocate an entry from the smem item */ | |
345 | strlcpy(buf, entry->name, SMP2P_MAX_ENTRY_NAME); | |
e7306dd7 | 346 | memcpy(out->entries[out->valid_entries].name, buf, SMP2P_MAX_ENTRY_NAME); |
50e99641 BA |
347 | |
348 | /* Make the logical entry reference the physical value */ | |
349 | entry->value = &out->entries[out->valid_entries].value; | |
350 | ||
63af8e44 BA |
351 | out->valid_entries++; |
352 | ||
50e99641 BA |
353 | entry->state = qcom_smem_state_register(node, &smp2p_state_ops, entry); |
354 | if (IS_ERR(entry->state)) { | |
355 | dev_err(smp2p->dev, "failed to register qcom_smem_state\n"); | |
356 | return PTR_ERR(entry->state); | |
357 | } | |
358 | ||
359 | return 0; | |
360 | } | |
361 | ||
362 | static int qcom_smp2p_alloc_outbound_item(struct qcom_smp2p *smp2p) | |
363 | { | |
364 | struct smp2p_smem_item *out; | |
365 | unsigned smem_id = smp2p->smem_items[SMP2P_OUTBOUND]; | |
366 | unsigned pid = smp2p->remote_pid; | |
367 | int ret; | |
368 | ||
369 | ret = qcom_smem_alloc(pid, smem_id, sizeof(*out)); | |
370 | if (ret < 0 && ret != -EEXIST) { | |
371 | if (ret != -EPROBE_DEFER) | |
372 | dev_err(smp2p->dev, | |
373 | "unable to allocate local smp2p item\n"); | |
374 | return ret; | |
375 | } | |
376 | ||
377 | out = qcom_smem_get(pid, smem_id, NULL); | |
378 | if (IS_ERR(out)) { | |
379 | dev_err(smp2p->dev, "Unable to acquire local smp2p item\n"); | |
380 | return PTR_ERR(out); | |
381 | } | |
382 | ||
383 | memset(out, 0, sizeof(*out)); | |
384 | out->magic = SMP2P_MAGIC; | |
385 | out->local_pid = smp2p->local_pid; | |
386 | out->remote_pid = smp2p->remote_pid; | |
387 | out->total_entries = SMP2P_MAX_ENTRY; | |
388 | out->valid_entries = 0; | |
389 | ||
390 | /* | |
391 | * Make sure the rest of the header is written before we validate the | |
392 | * item by writing a valid version number. | |
393 | */ | |
394 | wmb(); | |
395 | out->version = 1; | |
396 | ||
397 | qcom_smp2p_kick(smp2p); | |
398 | ||
399 | smp2p->out = out; | |
400 | ||
401 | return 0; | |
402 | } | |
403 | ||
404 | static int smp2p_parse_ipc(struct qcom_smp2p *smp2p) | |
405 | { | |
406 | struct device_node *syscon; | |
407 | struct device *dev = smp2p->dev; | |
408 | const char *key; | |
409 | int ret; | |
410 | ||
411 | syscon = of_parse_phandle(dev->of_node, "qcom,ipc", 0); | |
412 | if (!syscon) { | |
413 | dev_err(dev, "no qcom,ipc node\n"); | |
414 | return -ENODEV; | |
415 | } | |
416 | ||
417 | smp2p->ipc_regmap = syscon_node_to_regmap(syscon); | |
418 | if (IS_ERR(smp2p->ipc_regmap)) | |
419 | return PTR_ERR(smp2p->ipc_regmap); | |
420 | ||
421 | key = "qcom,ipc"; | |
422 | ret = of_property_read_u32_index(dev->of_node, key, 1, &smp2p->ipc_offset); | |
423 | if (ret < 0) { | |
424 | dev_err(dev, "no offset in %s\n", key); | |
425 | return -EINVAL; | |
426 | } | |
427 | ||
428 | ret = of_property_read_u32_index(dev->of_node, key, 2, &smp2p->ipc_bit); | |
429 | if (ret < 0) { | |
430 | dev_err(dev, "no bit in %s\n", key); | |
431 | return -EINVAL; | |
432 | } | |
433 | ||
434 | return 0; | |
435 | } | |
436 | ||
437 | static int qcom_smp2p_probe(struct platform_device *pdev) | |
438 | { | |
439 | struct smp2p_entry *entry; | |
440 | struct device_node *node; | |
441 | struct qcom_smp2p *smp2p; | |
442 | const char *key; | |
443 | int irq; | |
444 | int ret; | |
445 | ||
446 | smp2p = devm_kzalloc(&pdev->dev, sizeof(*smp2p), GFP_KERNEL); | |
447 | if (!smp2p) | |
448 | return -ENOMEM; | |
449 | ||
450 | smp2p->dev = &pdev->dev; | |
451 | INIT_LIST_HEAD(&smp2p->inbound); | |
452 | INIT_LIST_HEAD(&smp2p->outbound); | |
453 | ||
454 | platform_set_drvdata(pdev, smp2p); | |
455 | ||
456 | ret = smp2p_parse_ipc(smp2p); | |
457 | if (ret) | |
458 | return ret; | |
459 | ||
460 | key = "qcom,smem"; | |
461 | ret = of_property_read_u32_array(pdev->dev.of_node, key, | |
462 | smp2p->smem_items, 2); | |
463 | if (ret) | |
464 | return ret; | |
465 | ||
466 | key = "qcom,local-pid"; | |
467 | ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->local_pid); | |
468 | if (ret < 0) { | |
469 | dev_err(&pdev->dev, "failed to read %s\n", key); | |
470 | return -EINVAL; | |
471 | } | |
472 | ||
473 | key = "qcom,remote-pid"; | |
474 | ret = of_property_read_u32(pdev->dev.of_node, key, &smp2p->remote_pid); | |
475 | if (ret < 0) { | |
476 | dev_err(&pdev->dev, "failed to read %s\n", key); | |
477 | return -EINVAL; | |
478 | } | |
479 | ||
480 | irq = platform_get_irq(pdev, 0); | |
481 | if (irq < 0) { | |
482 | dev_err(&pdev->dev, "unable to acquire smp2p interrupt\n"); | |
483 | return irq; | |
484 | } | |
485 | ||
486 | ret = qcom_smp2p_alloc_outbound_item(smp2p); | |
487 | if (ret < 0) | |
488 | return ret; | |
489 | ||
490 | for_each_available_child_of_node(pdev->dev.of_node, node) { | |
491 | entry = devm_kzalloc(&pdev->dev, sizeof(*entry), GFP_KERNEL); | |
492 | if (!entry) { | |
493 | ret = -ENOMEM; | |
494 | goto unwind_interfaces; | |
495 | } | |
496 | ||
497 | entry->smp2p = smp2p; | |
498 | spin_lock_init(&entry->lock); | |
499 | ||
500 | ret = of_property_read_string(node, "qcom,entry-name", &entry->name); | |
501 | if (ret < 0) | |
502 | goto unwind_interfaces; | |
503 | ||
504 | if (of_property_read_bool(node, "interrupt-controller")) { | |
505 | ret = qcom_smp2p_inbound_entry(smp2p, entry, node); | |
506 | if (ret < 0) | |
507 | goto unwind_interfaces; | |
508 | ||
509 | list_add(&entry->node, &smp2p->inbound); | |
510 | } else { | |
511 | ret = qcom_smp2p_outbound_entry(smp2p, entry, node); | |
512 | if (ret < 0) | |
513 | goto unwind_interfaces; | |
514 | ||
515 | list_add(&entry->node, &smp2p->outbound); | |
516 | } | |
517 | } | |
518 | ||
519 | /* Kick the outgoing edge after allocating entries */ | |
520 | qcom_smp2p_kick(smp2p); | |
521 | ||
522 | ret = devm_request_threaded_irq(&pdev->dev, irq, | |
523 | NULL, qcom_smp2p_intr, | |
524 | IRQF_ONESHOT, | |
525 | "smp2p", (void *)smp2p); | |
526 | if (ret) { | |
527 | dev_err(&pdev->dev, "failed to request interrupt\n"); | |
528 | goto unwind_interfaces; | |
529 | } | |
530 | ||
531 | ||
532 | return 0; | |
533 | ||
534 | unwind_interfaces: | |
535 | list_for_each_entry(entry, &smp2p->inbound, node) | |
536 | irq_domain_remove(entry->domain); | |
537 | ||
538 | list_for_each_entry(entry, &smp2p->outbound, node) | |
539 | qcom_smem_state_unregister(entry->state); | |
540 | ||
541 | smp2p->out->valid_entries = 0; | |
542 | ||
543 | return ret; | |
544 | } | |
545 | ||
546 | static int qcom_smp2p_remove(struct platform_device *pdev) | |
547 | { | |
548 | struct qcom_smp2p *smp2p = platform_get_drvdata(pdev); | |
549 | struct smp2p_entry *entry; | |
550 | ||
551 | list_for_each_entry(entry, &smp2p->inbound, node) | |
552 | irq_domain_remove(entry->domain); | |
553 | ||
554 | list_for_each_entry(entry, &smp2p->outbound, node) | |
555 | qcom_smem_state_unregister(entry->state); | |
556 | ||
557 | smp2p->out->valid_entries = 0; | |
558 | ||
559 | return 0; | |
560 | } | |
561 | ||
562 | static const struct of_device_id qcom_smp2p_of_match[] = { | |
563 | { .compatible = "qcom,smp2p" }, | |
564 | {} | |
565 | }; | |
566 | MODULE_DEVICE_TABLE(of, qcom_smp2p_of_match); | |
567 | ||
568 | static struct platform_driver qcom_smp2p_driver = { | |
569 | .probe = qcom_smp2p_probe, | |
570 | .remove = qcom_smp2p_remove, | |
571 | .driver = { | |
572 | .name = "qcom_smp2p", | |
573 | .of_match_table = qcom_smp2p_of_match, | |
574 | }, | |
575 | }; | |
576 | module_platform_driver(qcom_smp2p_driver); | |
577 | ||
578 | MODULE_DESCRIPTION("Qualcomm Shared Memory Point to Point driver"); | |
579 | MODULE_LICENSE("GPL v2"); |