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9ef4546c LJ |
1 | /* |
2 | * STi Mailbox | |
3 | * | |
4 | * Copyright (C) 2015 ST Microelectronics | |
5 | * | |
6 | * Author: Lee Jones <lee.jones@linaro.org> for ST Microelectronics | |
7 | * | |
8 | * Based on the original driver written by; | |
9 | * Alexandre Torgue, Olivier Lebreton and Loic Pallardy | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License as published by | |
13 | * the Free Software Foundation; either version 2 of the License, or | |
14 | * (at your option) any later version. | |
15 | */ | |
16 | ||
17 | #include <linux/err.h> | |
18 | #include <linux/interrupt.h> | |
19 | #include <linux/io.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/mailbox_controller.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/of.h> | |
24 | #include <linux/of_device.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/slab.h> | |
27 | ||
28 | #include "mailbox.h" | |
29 | ||
30 | #define STI_MBOX_INST_MAX 4 /* RAM saving: Max supported instances */ | |
31 | #define STI_MBOX_CHAN_MAX 20 /* RAM saving: Max supported channels */ | |
32 | ||
33 | #define STI_IRQ_VAL_OFFSET 0x04 /* Read interrupt status */ | |
34 | #define STI_IRQ_SET_OFFSET 0x24 /* Generate a Tx channel interrupt */ | |
35 | #define STI_IRQ_CLR_OFFSET 0x44 /* Clear pending Rx interrupts */ | |
36 | #define STI_ENA_VAL_OFFSET 0x64 /* Read enable status */ | |
37 | #define STI_ENA_SET_OFFSET 0x84 /* Enable a channel */ | |
38 | #define STI_ENA_CLR_OFFSET 0xa4 /* Disable a channel */ | |
39 | ||
40 | #define MBOX_BASE(mdev, inst) ((mdev)->base + ((inst) * 4)) | |
41 | ||
42 | /** | |
43 | * STi Mailbox device data | |
44 | * | |
45 | * An IP Mailbox is currently composed of 4 instances | |
46 | * Each instance is currently composed of 32 channels | |
47 | * This means that we have 128 channels per Mailbox | |
48 | * A channel an be used for TX or RX | |
49 | * | |
50 | * @dev: Device to which it is attached | |
51 | * @mbox: Representation of a communication channel controller | |
52 | * @base: Base address of the register mapping region | |
53 | * @name: Name of the mailbox | |
54 | * @enabled: Local copy of enabled channels | |
55 | * @lock: Mutex protecting enabled status | |
56 | */ | |
57 | struct sti_mbox_device { | |
58 | struct device *dev; | |
59 | struct mbox_controller *mbox; | |
60 | void __iomem *base; | |
61 | const char *name; | |
62 | u32 enabled[STI_MBOX_INST_MAX]; | |
63 | spinlock_t lock; | |
64 | }; | |
65 | ||
66 | /** | |
6c03663f | 67 | * STi Mailbox platform specific configuration |
9ef4546c LJ |
68 | * |
69 | * @num_inst: Maximum number of instances in one HW Mailbox | |
70 | * @num_chan: Maximum number of channel per instance | |
71 | */ | |
72 | struct sti_mbox_pdata { | |
73 | unsigned int num_inst; | |
74 | unsigned int num_chan; | |
75 | }; | |
76 | ||
77 | /** | |
78 | * STi Mailbox allocated channel information | |
79 | * | |
80 | * @mdev: Pointer to parent Mailbox device | |
81 | * @instance: Instance number channel resides in | |
82 | * @channel: Channel number pertaining to this container | |
83 | */ | |
84 | struct sti_channel { | |
85 | struct sti_mbox_device *mdev; | |
86 | unsigned int instance; | |
87 | unsigned int channel; | |
88 | }; | |
89 | ||
90 | static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan) | |
91 | { | |
92 | struct sti_channel *chan_info = chan->con_priv; | |
93 | struct sti_mbox_device *mdev = chan_info->mdev; | |
94 | unsigned int instance = chan_info->instance; | |
95 | unsigned int channel = chan_info->channel; | |
96 | ||
97 | return mdev->enabled[instance] & BIT(channel); | |
98 | } | |
99 | ||
100 | static inline | |
101 | struct mbox_chan *sti_mbox_to_channel(struct mbox_controller *mbox, | |
102 | unsigned int instance, | |
103 | unsigned int channel) | |
104 | { | |
105 | struct sti_channel *chan_info; | |
106 | int i; | |
107 | ||
108 | for (i = 0; i < mbox->num_chans; i++) { | |
109 | chan_info = mbox->chans[i].con_priv; | |
110 | if (chan_info && | |
111 | chan_info->instance == instance && | |
112 | chan_info->channel == channel) | |
113 | return &mbox->chans[i]; | |
114 | } | |
115 | ||
116 | dev_err(mbox->dev, | |
117 | "Channel not registered: instance: %d channel: %d\n", | |
118 | instance, channel); | |
119 | ||
120 | return NULL; | |
121 | } | |
122 | ||
123 | static void sti_mbox_enable_channel(struct mbox_chan *chan) | |
124 | { | |
125 | struct sti_channel *chan_info = chan->con_priv; | |
126 | struct sti_mbox_device *mdev = chan_info->mdev; | |
127 | unsigned int instance = chan_info->instance; | |
128 | unsigned int channel = chan_info->channel; | |
129 | unsigned long flags; | |
130 | void __iomem *base = MBOX_BASE(mdev, instance); | |
131 | ||
132 | spin_lock_irqsave(&mdev->lock, flags); | |
133 | mdev->enabled[instance] |= BIT(channel); | |
134 | writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET); | |
135 | spin_unlock_irqrestore(&mdev->lock, flags); | |
136 | } | |
137 | ||
138 | static void sti_mbox_disable_channel(struct mbox_chan *chan) | |
139 | { | |
140 | struct sti_channel *chan_info = chan->con_priv; | |
141 | struct sti_mbox_device *mdev = chan_info->mdev; | |
142 | unsigned int instance = chan_info->instance; | |
143 | unsigned int channel = chan_info->channel; | |
144 | unsigned long flags; | |
145 | void __iomem *base = MBOX_BASE(mdev, instance); | |
146 | ||
147 | spin_lock_irqsave(&mdev->lock, flags); | |
148 | mdev->enabled[instance] &= ~BIT(channel); | |
149 | writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET); | |
150 | spin_unlock_irqrestore(&mdev->lock, flags); | |
151 | } | |
152 | ||
153 | static void sti_mbox_clear_irq(struct mbox_chan *chan) | |
154 | { | |
155 | struct sti_channel *chan_info = chan->con_priv; | |
156 | struct sti_mbox_device *mdev = chan_info->mdev; | |
157 | unsigned int instance = chan_info->instance; | |
158 | unsigned int channel = chan_info->channel; | |
159 | void __iomem *base = MBOX_BASE(mdev, instance); | |
160 | ||
161 | writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET); | |
162 | } | |
163 | ||
164 | static struct mbox_chan *sti_mbox_irq_to_channel(struct sti_mbox_device *mdev, | |
165 | unsigned int instance) | |
166 | { | |
167 | struct mbox_controller *mbox = mdev->mbox; | |
168 | struct mbox_chan *chan = NULL; | |
169 | unsigned int channel; | |
170 | unsigned long bits; | |
171 | void __iomem *base = MBOX_BASE(mdev, instance); | |
172 | ||
173 | bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET); | |
174 | if (!bits) | |
175 | /* No IRQs fired in specified instance */ | |
176 | return NULL; | |
177 | ||
178 | /* An IRQ has fired, find the associated channel */ | |
179 | for (channel = 0; bits; channel++) { | |
180 | if (!test_and_clear_bit(channel, &bits)) | |
181 | continue; | |
182 | ||
183 | chan = sti_mbox_to_channel(mbox, instance, channel); | |
184 | if (chan) { | |
185 | dev_dbg(mbox->dev, | |
186 | "IRQ fired on instance: %d channel: %d\n", | |
187 | instance, channel); | |
188 | break; | |
189 | } | |
190 | } | |
191 | ||
192 | return chan; | |
193 | } | |
194 | ||
195 | static irqreturn_t sti_mbox_thread_handler(int irq, void *data) | |
196 | { | |
197 | struct sti_mbox_device *mdev = data; | |
198 | struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); | |
199 | struct mbox_chan *chan; | |
200 | unsigned int instance; | |
201 | ||
202 | for (instance = 0; instance < pdata->num_inst; instance++) { | |
203 | keep_looking: | |
204 | chan = sti_mbox_irq_to_channel(mdev, instance); | |
205 | if (!chan) | |
206 | continue; | |
207 | ||
208 | mbox_chan_received_data(chan, NULL); | |
209 | sti_mbox_clear_irq(chan); | |
210 | sti_mbox_enable_channel(chan); | |
211 | goto keep_looking; | |
212 | } | |
213 | ||
214 | return IRQ_HANDLED; | |
215 | } | |
216 | ||
217 | static irqreturn_t sti_mbox_irq_handler(int irq, void *data) | |
218 | { | |
219 | struct sti_mbox_device *mdev = data; | |
220 | struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); | |
221 | struct sti_channel *chan_info; | |
222 | struct mbox_chan *chan; | |
223 | unsigned int instance; | |
224 | int ret = IRQ_NONE; | |
225 | ||
226 | for (instance = 0; instance < pdata->num_inst; instance++) { | |
227 | chan = sti_mbox_irq_to_channel(mdev, instance); | |
228 | if (!chan) | |
229 | continue; | |
230 | chan_info = chan->con_priv; | |
231 | ||
232 | if (!sti_mbox_channel_is_enabled(chan)) { | |
233 | dev_warn(mdev->dev, | |
234 | "Unexpected IRQ: %s\n" | |
235 | " instance: %d: channel: %d [enabled: %x]\n", | |
236 | mdev->name, chan_info->instance, | |
237 | chan_info->channel, mdev->enabled[instance]); | |
238 | ||
239 | /* Only handle IRQ if no other valid IRQs were found */ | |
240 | if (ret == IRQ_NONE) | |
241 | ret = IRQ_HANDLED; | |
242 | continue; | |
243 | } | |
244 | ||
245 | sti_mbox_disable_channel(chan); | |
246 | ret = IRQ_WAKE_THREAD; | |
247 | } | |
248 | ||
249 | if (ret == IRQ_NONE) | |
250 | dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n"); | |
251 | ||
252 | return ret; | |
253 | } | |
254 | ||
255 | static bool sti_mbox_tx_is_ready(struct mbox_chan *chan) | |
256 | { | |
257 | struct sti_channel *chan_info = chan->con_priv; | |
258 | struct sti_mbox_device *mdev = chan_info->mdev; | |
259 | unsigned int instance = chan_info->instance; | |
260 | unsigned int channel = chan_info->channel; | |
261 | void __iomem *base = MBOX_BASE(mdev, instance); | |
262 | ||
263 | if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) { | |
264 | dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n", | |
265 | mdev->name, instance, channel); | |
266 | return false; | |
267 | } | |
268 | ||
269 | if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) { | |
270 | dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n", | |
271 | mdev->name, instance, channel); | |
272 | return false; | |
273 | } | |
274 | ||
275 | return true; | |
276 | } | |
277 | ||
278 | static int sti_mbox_send_data(struct mbox_chan *chan, void *data) | |
279 | { | |
280 | struct sti_channel *chan_info = chan->con_priv; | |
281 | struct sti_mbox_device *mdev = chan_info->mdev; | |
282 | unsigned int instance = chan_info->instance; | |
283 | unsigned int channel = chan_info->channel; | |
284 | void __iomem *base = MBOX_BASE(mdev, instance); | |
285 | ||
286 | /* Send event to co-processor */ | |
287 | writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET); | |
288 | ||
289 | dev_dbg(mdev->dev, | |
290 | "Sent via Mailbox %s: instance: %d channel: %d\n", | |
291 | mdev->name, instance, channel); | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | static int sti_mbox_startup_chan(struct mbox_chan *chan) | |
297 | { | |
298 | sti_mbox_clear_irq(chan); | |
299 | sti_mbox_enable_channel(chan); | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | static void sti_mbox_shutdown_chan(struct mbox_chan *chan) | |
305 | { | |
306 | struct sti_channel *chan_info = chan->con_priv; | |
307 | struct mbox_controller *mbox = chan_info->mdev->mbox; | |
308 | int i; | |
309 | ||
310 | for (i = 0; i < mbox->num_chans; i++) | |
311 | if (chan == &mbox->chans[i]) | |
312 | break; | |
313 | ||
314 | if (mbox->num_chans == i) { | |
315 | dev_warn(mbox->dev, "Request to free non-existent channel\n"); | |
316 | return; | |
317 | } | |
318 | ||
319 | /* Reset channel */ | |
320 | sti_mbox_disable_channel(chan); | |
321 | sti_mbox_clear_irq(chan); | |
322 | chan->con_priv = NULL; | |
323 | } | |
324 | ||
325 | static struct mbox_chan *sti_mbox_xlate(struct mbox_controller *mbox, | |
326 | const struct of_phandle_args *spec) | |
327 | { | |
328 | struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev); | |
329 | struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); | |
330 | struct sti_channel *chan_info; | |
331 | struct mbox_chan *chan = NULL; | |
332 | unsigned int instance = spec->args[0]; | |
333 | unsigned int channel = spec->args[1]; | |
334 | int i; | |
335 | ||
336 | /* Bounds checking */ | |
337 | if (instance >= pdata->num_inst || channel >= pdata->num_chan) { | |
338 | dev_err(mbox->dev, | |
339 | "Invalid channel requested instance: %d channel: %d\n", | |
340 | instance, channel); | |
341 | return ERR_PTR(-EINVAL); | |
342 | } | |
343 | ||
344 | for (i = 0; i < mbox->num_chans; i++) { | |
345 | chan_info = mbox->chans[i].con_priv; | |
346 | ||
347 | /* Is requested channel free? */ | |
348 | if (chan_info && | |
349 | mbox->dev == chan_info->mdev->dev && | |
350 | instance == chan_info->instance && | |
351 | channel == chan_info->channel) { | |
352 | ||
353 | dev_err(mbox->dev, "Channel in use\n"); | |
354 | return ERR_PTR(-EBUSY); | |
355 | } | |
356 | ||
357 | /* | |
358 | * Find the first free slot, then continue checking | |
359 | * to see if requested channel is in use | |
360 | */ | |
361 | if (!chan && !chan_info) | |
362 | chan = &mbox->chans[i]; | |
363 | } | |
364 | ||
365 | if (!chan) { | |
366 | dev_err(mbox->dev, "No free channels left\n"); | |
367 | return ERR_PTR(-EBUSY); | |
368 | } | |
369 | ||
370 | chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL); | |
371 | if (!chan_info) | |
372 | return ERR_PTR(-ENOMEM); | |
373 | ||
374 | chan_info->mdev = mdev; | |
375 | chan_info->instance = instance; | |
376 | chan_info->channel = channel; | |
377 | ||
378 | chan->con_priv = chan_info; | |
379 | ||
380 | dev_info(mbox->dev, | |
381 | "Mbox: %s: Created channel: instance: %d channel: %d\n", | |
382 | mdev->name, instance, channel); | |
383 | ||
384 | return chan; | |
385 | } | |
386 | ||
bfbcfa77 | 387 | static const struct mbox_chan_ops sti_mbox_ops = { |
9ef4546c LJ |
388 | .startup = sti_mbox_startup_chan, |
389 | .shutdown = sti_mbox_shutdown_chan, | |
390 | .send_data = sti_mbox_send_data, | |
391 | .last_tx_done = sti_mbox_tx_is_ready, | |
392 | }; | |
393 | ||
394 | static const struct sti_mbox_pdata mbox_stih407_pdata = { | |
395 | .num_inst = 4, | |
396 | .num_chan = 32, | |
397 | }; | |
398 | ||
399 | static const struct of_device_id sti_mailbox_match[] = { | |
400 | { | |
401 | .compatible = "st,stih407-mailbox", | |
402 | .data = (void *)&mbox_stih407_pdata | |
403 | }, | |
404 | { } | |
405 | }; | |
406 | ||
407 | static int sti_mbox_probe(struct platform_device *pdev) | |
408 | { | |
409 | const struct of_device_id *match; | |
410 | struct mbox_controller *mbox; | |
411 | struct sti_mbox_device *mdev; | |
412 | struct device_node *np = pdev->dev.of_node; | |
413 | struct mbox_chan *chans; | |
414 | struct resource *res; | |
415 | int irq; | |
416 | int ret; | |
417 | ||
418 | match = of_match_device(sti_mailbox_match, &pdev->dev); | |
419 | if (!match) { | |
420 | dev_err(&pdev->dev, "No configuration found\n"); | |
421 | return -ENODEV; | |
422 | } | |
423 | pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data; | |
424 | ||
425 | mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL); | |
426 | if (!mdev) | |
427 | return -ENOMEM; | |
428 | ||
429 | platform_set_drvdata(pdev, mdev); | |
430 | ||
431 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
432 | mdev->base = devm_ioremap_resource(&pdev->dev, res); | |
433 | if (!mdev->base) | |
434 | return -ENOMEM; | |
435 | ||
436 | ret = of_property_read_string(np, "mbox-name", &mdev->name); | |
437 | if (ret) | |
438 | mdev->name = np->full_name; | |
439 | ||
440 | mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL); | |
441 | if (!mbox) | |
442 | return -ENOMEM; | |
443 | ||
444 | chans = devm_kzalloc(&pdev->dev, | |
445 | sizeof(*chans) * STI_MBOX_CHAN_MAX, GFP_KERNEL); | |
446 | if (!chans) | |
447 | return -ENOMEM; | |
448 | ||
449 | mdev->dev = &pdev->dev; | |
450 | mdev->mbox = mbox; | |
451 | ||
452 | spin_lock_init(&mdev->lock); | |
453 | ||
454 | /* STi Mailbox does not have a Tx-Done or Tx-Ready IRQ */ | |
455 | mbox->txdone_irq = false; | |
456 | mbox->txdone_poll = true; | |
457 | mbox->txpoll_period = 100; | |
458 | mbox->ops = &sti_mbox_ops; | |
459 | mbox->dev = mdev->dev; | |
460 | mbox->of_xlate = sti_mbox_xlate; | |
461 | mbox->chans = chans; | |
462 | mbox->num_chans = STI_MBOX_CHAN_MAX; | |
463 | ||
464 | ret = mbox_controller_register(mbox); | |
465 | if (ret) | |
466 | return ret; | |
467 | ||
468 | /* It's okay for Tx Mailboxes to not supply IRQs */ | |
469 | irq = platform_get_irq(pdev, 0); | |
470 | if (irq < 0) { | |
471 | dev_info(&pdev->dev, | |
472 | "%s: Registered Tx only Mailbox\n", mdev->name); | |
473 | return 0; | |
474 | } | |
475 | ||
476 | ret = devm_request_threaded_irq(&pdev->dev, irq, | |
477 | sti_mbox_irq_handler, | |
478 | sti_mbox_thread_handler, | |
479 | IRQF_ONESHOT, mdev->name, mdev); | |
480 | if (ret) { | |
481 | dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq); | |
482 | mbox_controller_unregister(mbox); | |
483 | return -EINVAL; | |
484 | } | |
485 | ||
486 | dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name); | |
487 | ||
488 | return 0; | |
489 | } | |
490 | ||
491 | static int sti_mbox_remove(struct platform_device *pdev) | |
492 | { | |
493 | struct sti_mbox_device *mdev = platform_get_drvdata(pdev); | |
494 | ||
495 | mbox_controller_unregister(mdev->mbox); | |
496 | ||
497 | return 0; | |
498 | } | |
499 | ||
500 | static struct platform_driver sti_mbox_driver = { | |
501 | .probe = sti_mbox_probe, | |
502 | .remove = sti_mbox_remove, | |
503 | .driver = { | |
504 | .name = "sti-mailbox", | |
505 | .of_match_table = sti_mailbox_match, | |
506 | }, | |
507 | }; | |
508 | module_platform_driver(sti_mbox_driver); | |
509 | ||
510 | MODULE_LICENSE("GPL"); | |
511 | MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller"); | |
512 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org"); | |
513 | MODULE_ALIAS("platform:mailbox-sti"); |