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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
9ef4546c LJ |
2 | /* |
3 | * STi Mailbox | |
4 | * | |
5 | * Copyright (C) 2015 ST Microelectronics | |
6 | * | |
7 | * Author: Lee Jones <lee.jones@linaro.org> for ST Microelectronics | |
8 | * | |
9 | * Based on the original driver written by; | |
10 | * Alexandre Torgue, Olivier Lebreton and Loic Pallardy | |
9ef4546c LJ |
11 | */ |
12 | ||
13 | #include <linux/err.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/io.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/mailbox_controller.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/of.h> | |
9ef4546c | 20 | #include <linux/platform_device.h> |
5cb5d0c9 | 21 | #include <linux/property.h> |
9ef4546c LJ |
22 | #include <linux/slab.h> |
23 | ||
24 | #include "mailbox.h" | |
25 | ||
26 | #define STI_MBOX_INST_MAX 4 /* RAM saving: Max supported instances */ | |
27 | #define STI_MBOX_CHAN_MAX 20 /* RAM saving: Max supported channels */ | |
28 | ||
29 | #define STI_IRQ_VAL_OFFSET 0x04 /* Read interrupt status */ | |
30 | #define STI_IRQ_SET_OFFSET 0x24 /* Generate a Tx channel interrupt */ | |
31 | #define STI_IRQ_CLR_OFFSET 0x44 /* Clear pending Rx interrupts */ | |
32 | #define STI_ENA_VAL_OFFSET 0x64 /* Read enable status */ | |
33 | #define STI_ENA_SET_OFFSET 0x84 /* Enable a channel */ | |
34 | #define STI_ENA_CLR_OFFSET 0xa4 /* Disable a channel */ | |
35 | ||
36 | #define MBOX_BASE(mdev, inst) ((mdev)->base + ((inst) * 4)) | |
37 | ||
38 | /** | |
23e6a7ca | 39 | * struct sti_mbox_device - STi Mailbox device data |
9ef4546c LJ |
40 | * |
41 | * @dev: Device to which it is attached | |
42 | * @mbox: Representation of a communication channel controller | |
43 | * @base: Base address of the register mapping region | |
44 | * @name: Name of the mailbox | |
45 | * @enabled: Local copy of enabled channels | |
46 | * @lock: Mutex protecting enabled status | |
23e6a7ca RD |
47 | * |
48 | * An IP Mailbox is currently composed of 4 instances | |
49 | * Each instance is currently composed of 32 channels | |
50 | * This means that we have 128 channels per Mailbox | |
51 | * A channel an be used for TX or RX | |
9ef4546c LJ |
52 | */ |
53 | struct sti_mbox_device { | |
54 | struct device *dev; | |
55 | struct mbox_controller *mbox; | |
56 | void __iomem *base; | |
57 | const char *name; | |
58 | u32 enabled[STI_MBOX_INST_MAX]; | |
59 | spinlock_t lock; | |
60 | }; | |
61 | ||
62 | /** | |
23e6a7ca | 63 | * struct sti_mbox_pdata - STi Mailbox platform specific configuration |
9ef4546c LJ |
64 | * |
65 | * @num_inst: Maximum number of instances in one HW Mailbox | |
66 | * @num_chan: Maximum number of channel per instance | |
67 | */ | |
68 | struct sti_mbox_pdata { | |
69 | unsigned int num_inst; | |
70 | unsigned int num_chan; | |
71 | }; | |
72 | ||
73 | /** | |
23e6a7ca | 74 | * struct sti_channel - STi Mailbox allocated channel information |
9ef4546c LJ |
75 | * |
76 | * @mdev: Pointer to parent Mailbox device | |
77 | * @instance: Instance number channel resides in | |
78 | * @channel: Channel number pertaining to this container | |
79 | */ | |
80 | struct sti_channel { | |
81 | struct sti_mbox_device *mdev; | |
82 | unsigned int instance; | |
83 | unsigned int channel; | |
84 | }; | |
85 | ||
86 | static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan) | |
87 | { | |
88 | struct sti_channel *chan_info = chan->con_priv; | |
89 | struct sti_mbox_device *mdev = chan_info->mdev; | |
90 | unsigned int instance = chan_info->instance; | |
91 | unsigned int channel = chan_info->channel; | |
92 | ||
93 | return mdev->enabled[instance] & BIT(channel); | |
94 | } | |
95 | ||
96 | static inline | |
97 | struct mbox_chan *sti_mbox_to_channel(struct mbox_controller *mbox, | |
98 | unsigned int instance, | |
99 | unsigned int channel) | |
100 | { | |
101 | struct sti_channel *chan_info; | |
102 | int i; | |
103 | ||
104 | for (i = 0; i < mbox->num_chans; i++) { | |
105 | chan_info = mbox->chans[i].con_priv; | |
106 | if (chan_info && | |
107 | chan_info->instance == instance && | |
108 | chan_info->channel == channel) | |
109 | return &mbox->chans[i]; | |
110 | } | |
111 | ||
112 | dev_err(mbox->dev, | |
113 | "Channel not registered: instance: %d channel: %d\n", | |
114 | instance, channel); | |
115 | ||
116 | return NULL; | |
117 | } | |
118 | ||
119 | static void sti_mbox_enable_channel(struct mbox_chan *chan) | |
120 | { | |
121 | struct sti_channel *chan_info = chan->con_priv; | |
122 | struct sti_mbox_device *mdev = chan_info->mdev; | |
123 | unsigned int instance = chan_info->instance; | |
124 | unsigned int channel = chan_info->channel; | |
125 | unsigned long flags; | |
126 | void __iomem *base = MBOX_BASE(mdev, instance); | |
127 | ||
128 | spin_lock_irqsave(&mdev->lock, flags); | |
129 | mdev->enabled[instance] |= BIT(channel); | |
130 | writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET); | |
131 | spin_unlock_irqrestore(&mdev->lock, flags); | |
132 | } | |
133 | ||
134 | static void sti_mbox_disable_channel(struct mbox_chan *chan) | |
135 | { | |
136 | struct sti_channel *chan_info = chan->con_priv; | |
137 | struct sti_mbox_device *mdev = chan_info->mdev; | |
138 | unsigned int instance = chan_info->instance; | |
139 | unsigned int channel = chan_info->channel; | |
140 | unsigned long flags; | |
141 | void __iomem *base = MBOX_BASE(mdev, instance); | |
142 | ||
143 | spin_lock_irqsave(&mdev->lock, flags); | |
144 | mdev->enabled[instance] &= ~BIT(channel); | |
145 | writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET); | |
146 | spin_unlock_irqrestore(&mdev->lock, flags); | |
147 | } | |
148 | ||
149 | static void sti_mbox_clear_irq(struct mbox_chan *chan) | |
150 | { | |
151 | struct sti_channel *chan_info = chan->con_priv; | |
152 | struct sti_mbox_device *mdev = chan_info->mdev; | |
153 | unsigned int instance = chan_info->instance; | |
154 | unsigned int channel = chan_info->channel; | |
155 | void __iomem *base = MBOX_BASE(mdev, instance); | |
156 | ||
157 | writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET); | |
158 | } | |
159 | ||
160 | static struct mbox_chan *sti_mbox_irq_to_channel(struct sti_mbox_device *mdev, | |
161 | unsigned int instance) | |
162 | { | |
163 | struct mbox_controller *mbox = mdev->mbox; | |
164 | struct mbox_chan *chan = NULL; | |
165 | unsigned int channel; | |
166 | unsigned long bits; | |
167 | void __iomem *base = MBOX_BASE(mdev, instance); | |
168 | ||
169 | bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET); | |
170 | if (!bits) | |
171 | /* No IRQs fired in specified instance */ | |
172 | return NULL; | |
173 | ||
174 | /* An IRQ has fired, find the associated channel */ | |
175 | for (channel = 0; bits; channel++) { | |
176 | if (!test_and_clear_bit(channel, &bits)) | |
177 | continue; | |
178 | ||
179 | chan = sti_mbox_to_channel(mbox, instance, channel); | |
180 | if (chan) { | |
181 | dev_dbg(mbox->dev, | |
182 | "IRQ fired on instance: %d channel: %d\n", | |
183 | instance, channel); | |
184 | break; | |
185 | } | |
186 | } | |
187 | ||
188 | return chan; | |
189 | } | |
190 | ||
191 | static irqreturn_t sti_mbox_thread_handler(int irq, void *data) | |
192 | { | |
193 | struct sti_mbox_device *mdev = data; | |
194 | struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); | |
195 | struct mbox_chan *chan; | |
196 | unsigned int instance; | |
197 | ||
198 | for (instance = 0; instance < pdata->num_inst; instance++) { | |
199 | keep_looking: | |
200 | chan = sti_mbox_irq_to_channel(mdev, instance); | |
201 | if (!chan) | |
202 | continue; | |
203 | ||
204 | mbox_chan_received_data(chan, NULL); | |
205 | sti_mbox_clear_irq(chan); | |
206 | sti_mbox_enable_channel(chan); | |
207 | goto keep_looking; | |
208 | } | |
209 | ||
210 | return IRQ_HANDLED; | |
211 | } | |
212 | ||
213 | static irqreturn_t sti_mbox_irq_handler(int irq, void *data) | |
214 | { | |
215 | struct sti_mbox_device *mdev = data; | |
216 | struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); | |
217 | struct sti_channel *chan_info; | |
218 | struct mbox_chan *chan; | |
219 | unsigned int instance; | |
220 | int ret = IRQ_NONE; | |
221 | ||
222 | for (instance = 0; instance < pdata->num_inst; instance++) { | |
223 | chan = sti_mbox_irq_to_channel(mdev, instance); | |
224 | if (!chan) | |
225 | continue; | |
226 | chan_info = chan->con_priv; | |
227 | ||
228 | if (!sti_mbox_channel_is_enabled(chan)) { | |
229 | dev_warn(mdev->dev, | |
230 | "Unexpected IRQ: %s\n" | |
231 | " instance: %d: channel: %d [enabled: %x]\n", | |
232 | mdev->name, chan_info->instance, | |
233 | chan_info->channel, mdev->enabled[instance]); | |
234 | ||
235 | /* Only handle IRQ if no other valid IRQs were found */ | |
236 | if (ret == IRQ_NONE) | |
237 | ret = IRQ_HANDLED; | |
238 | continue; | |
239 | } | |
240 | ||
241 | sti_mbox_disable_channel(chan); | |
242 | ret = IRQ_WAKE_THREAD; | |
243 | } | |
244 | ||
245 | if (ret == IRQ_NONE) | |
246 | dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n"); | |
247 | ||
248 | return ret; | |
249 | } | |
250 | ||
251 | static bool sti_mbox_tx_is_ready(struct mbox_chan *chan) | |
252 | { | |
253 | struct sti_channel *chan_info = chan->con_priv; | |
254 | struct sti_mbox_device *mdev = chan_info->mdev; | |
255 | unsigned int instance = chan_info->instance; | |
256 | unsigned int channel = chan_info->channel; | |
257 | void __iomem *base = MBOX_BASE(mdev, instance); | |
258 | ||
259 | if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) { | |
260 | dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n", | |
261 | mdev->name, instance, channel); | |
262 | return false; | |
263 | } | |
264 | ||
265 | if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) { | |
266 | dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n", | |
267 | mdev->name, instance, channel); | |
268 | return false; | |
269 | } | |
270 | ||
271 | return true; | |
272 | } | |
273 | ||
274 | static int sti_mbox_send_data(struct mbox_chan *chan, void *data) | |
275 | { | |
276 | struct sti_channel *chan_info = chan->con_priv; | |
277 | struct sti_mbox_device *mdev = chan_info->mdev; | |
278 | unsigned int instance = chan_info->instance; | |
279 | unsigned int channel = chan_info->channel; | |
280 | void __iomem *base = MBOX_BASE(mdev, instance); | |
281 | ||
282 | /* Send event to co-processor */ | |
283 | writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET); | |
284 | ||
285 | dev_dbg(mdev->dev, | |
286 | "Sent via Mailbox %s: instance: %d channel: %d\n", | |
287 | mdev->name, instance, channel); | |
288 | ||
289 | return 0; | |
290 | } | |
291 | ||
292 | static int sti_mbox_startup_chan(struct mbox_chan *chan) | |
293 | { | |
294 | sti_mbox_clear_irq(chan); | |
295 | sti_mbox_enable_channel(chan); | |
296 | ||
297 | return 0; | |
298 | } | |
299 | ||
300 | static void sti_mbox_shutdown_chan(struct mbox_chan *chan) | |
301 | { | |
302 | struct sti_channel *chan_info = chan->con_priv; | |
303 | struct mbox_controller *mbox = chan_info->mdev->mbox; | |
304 | int i; | |
305 | ||
306 | for (i = 0; i < mbox->num_chans; i++) | |
307 | if (chan == &mbox->chans[i]) | |
308 | break; | |
309 | ||
310 | if (mbox->num_chans == i) { | |
311 | dev_warn(mbox->dev, "Request to free non-existent channel\n"); | |
312 | return; | |
313 | } | |
314 | ||
315 | /* Reset channel */ | |
316 | sti_mbox_disable_channel(chan); | |
317 | sti_mbox_clear_irq(chan); | |
318 | chan->con_priv = NULL; | |
319 | } | |
320 | ||
321 | static struct mbox_chan *sti_mbox_xlate(struct mbox_controller *mbox, | |
322 | const struct of_phandle_args *spec) | |
323 | { | |
324 | struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev); | |
325 | struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); | |
326 | struct sti_channel *chan_info; | |
327 | struct mbox_chan *chan = NULL; | |
328 | unsigned int instance = spec->args[0]; | |
329 | unsigned int channel = spec->args[1]; | |
330 | int i; | |
331 | ||
332 | /* Bounds checking */ | |
333 | if (instance >= pdata->num_inst || channel >= pdata->num_chan) { | |
334 | dev_err(mbox->dev, | |
335 | "Invalid channel requested instance: %d channel: %d\n", | |
336 | instance, channel); | |
337 | return ERR_PTR(-EINVAL); | |
338 | } | |
339 | ||
340 | for (i = 0; i < mbox->num_chans; i++) { | |
341 | chan_info = mbox->chans[i].con_priv; | |
342 | ||
343 | /* Is requested channel free? */ | |
344 | if (chan_info && | |
345 | mbox->dev == chan_info->mdev->dev && | |
346 | instance == chan_info->instance && | |
347 | channel == chan_info->channel) { | |
348 | ||
349 | dev_err(mbox->dev, "Channel in use\n"); | |
350 | return ERR_PTR(-EBUSY); | |
351 | } | |
352 | ||
353 | /* | |
354 | * Find the first free slot, then continue checking | |
355 | * to see if requested channel is in use | |
356 | */ | |
357 | if (!chan && !chan_info) | |
358 | chan = &mbox->chans[i]; | |
359 | } | |
360 | ||
361 | if (!chan) { | |
362 | dev_err(mbox->dev, "No free channels left\n"); | |
363 | return ERR_PTR(-EBUSY); | |
364 | } | |
365 | ||
366 | chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL); | |
367 | if (!chan_info) | |
368 | return ERR_PTR(-ENOMEM); | |
369 | ||
370 | chan_info->mdev = mdev; | |
371 | chan_info->instance = instance; | |
372 | chan_info->channel = channel; | |
373 | ||
374 | chan->con_priv = chan_info; | |
375 | ||
376 | dev_info(mbox->dev, | |
377 | "Mbox: %s: Created channel: instance: %d channel: %d\n", | |
378 | mdev->name, instance, channel); | |
379 | ||
380 | return chan; | |
381 | } | |
382 | ||
bfbcfa77 | 383 | static const struct mbox_chan_ops sti_mbox_ops = { |
9ef4546c LJ |
384 | .startup = sti_mbox_startup_chan, |
385 | .shutdown = sti_mbox_shutdown_chan, | |
386 | .send_data = sti_mbox_send_data, | |
387 | .last_tx_done = sti_mbox_tx_is_ready, | |
388 | }; | |
389 | ||
390 | static const struct sti_mbox_pdata mbox_stih407_pdata = { | |
391 | .num_inst = 4, | |
392 | .num_chan = 32, | |
393 | }; | |
394 | ||
395 | static const struct of_device_id sti_mailbox_match[] = { | |
396 | { | |
397 | .compatible = "st,stih407-mailbox", | |
398 | .data = (void *)&mbox_stih407_pdata | |
399 | }, | |
400 | { } | |
401 | }; | |
2f50497d | 402 | MODULE_DEVICE_TABLE(of, sti_mailbox_match); |
9ef4546c LJ |
403 | |
404 | static int sti_mbox_probe(struct platform_device *pdev) | |
405 | { | |
9ef4546c LJ |
406 | struct mbox_controller *mbox; |
407 | struct sti_mbox_device *mdev; | |
408 | struct device_node *np = pdev->dev.of_node; | |
409 | struct mbox_chan *chans; | |
9ef4546c LJ |
410 | int irq; |
411 | int ret; | |
412 | ||
5cb5d0c9 RH |
413 | pdev->dev.platform_data = (struct sti_mbox_pdata *)device_get_match_data(&pdev->dev); |
414 | if (!pdev->dev.platform_data) { | |
9ef4546c LJ |
415 | dev_err(&pdev->dev, "No configuration found\n"); |
416 | return -ENODEV; | |
417 | } | |
9ef4546c LJ |
418 | |
419 | mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL); | |
420 | if (!mdev) | |
421 | return -ENOMEM; | |
422 | ||
423 | platform_set_drvdata(pdev, mdev); | |
424 | ||
240c7e39 | 425 | mdev->base = devm_platform_ioremap_resource(pdev, 0); |
c430cf37 AKC |
426 | if (IS_ERR(mdev->base)) |
427 | return PTR_ERR(mdev->base); | |
9ef4546c LJ |
428 | |
429 | ret = of_property_read_string(np, "mbox-name", &mdev->name); | |
430 | if (ret) | |
431 | mdev->name = np->full_name; | |
432 | ||
433 | mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL); | |
434 | if (!mbox) | |
435 | return -ENOMEM; | |
436 | ||
a86854d0 KC |
437 | chans = devm_kcalloc(&pdev->dev, |
438 | STI_MBOX_CHAN_MAX, sizeof(*chans), GFP_KERNEL); | |
9ef4546c LJ |
439 | if (!chans) |
440 | return -ENOMEM; | |
441 | ||
442 | mdev->dev = &pdev->dev; | |
443 | mdev->mbox = mbox; | |
444 | ||
445 | spin_lock_init(&mdev->lock); | |
446 | ||
447 | /* STi Mailbox does not have a Tx-Done or Tx-Ready IRQ */ | |
448 | mbox->txdone_irq = false; | |
449 | mbox->txdone_poll = true; | |
450 | mbox->txpoll_period = 100; | |
451 | mbox->ops = &sti_mbox_ops; | |
452 | mbox->dev = mdev->dev; | |
453 | mbox->of_xlate = sti_mbox_xlate; | |
454 | mbox->chans = chans; | |
455 | mbox->num_chans = STI_MBOX_CHAN_MAX; | |
456 | ||
d0c196db | 457 | ret = devm_mbox_controller_register(&pdev->dev, mbox); |
9ef4546c LJ |
458 | if (ret) |
459 | return ret; | |
460 | ||
461 | /* It's okay for Tx Mailboxes to not supply IRQs */ | |
462 | irq = platform_get_irq(pdev, 0); | |
463 | if (irq < 0) { | |
464 | dev_info(&pdev->dev, | |
465 | "%s: Registered Tx only Mailbox\n", mdev->name); | |
466 | return 0; | |
467 | } | |
468 | ||
469 | ret = devm_request_threaded_irq(&pdev->dev, irq, | |
470 | sti_mbox_irq_handler, | |
471 | sti_mbox_thread_handler, | |
472 | IRQF_ONESHOT, mdev->name, mdev); | |
473 | if (ret) { | |
474 | dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq); | |
9ef4546c LJ |
475 | return -EINVAL; |
476 | } | |
477 | ||
478 | dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name); | |
479 | ||
480 | return 0; | |
481 | } | |
482 | ||
9ef4546c LJ |
483 | static struct platform_driver sti_mbox_driver = { |
484 | .probe = sti_mbox_probe, | |
9ef4546c LJ |
485 | .driver = { |
486 | .name = "sti-mailbox", | |
487 | .of_match_table = sti_mailbox_match, | |
488 | }, | |
489 | }; | |
490 | module_platform_driver(sti_mbox_driver); | |
491 | ||
492 | MODULE_LICENSE("GPL"); | |
493 | MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller"); | |
494 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org"); | |
495 | MODULE_ALIAS("platform:mailbox-sti"); |