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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
31#define STI_MBOX_CHAN_MAX 20
32
33#define STI_IRQ_VAL_OFFSET 0x04
34#define STI_IRQ_SET_OFFSET 0x24
35#define STI_IRQ_CLR_OFFSET 0x44
36#define STI_ENA_VAL_OFFSET 0x64
37#define STI_ENA_SET_OFFSET 0x84
38#define STI_ENA_CLR_OFFSET 0xa4
39
40#define MBOX_BASE(mdev, inst) ((mdev)->base + ((inst) * 4))
41
42
43
44
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56
57struct 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
67
68
69
70
71
72struct sti_mbox_pdata {
73 unsigned int num_inst;
74 unsigned int num_chan;
75};
76
77
78
79
80
81
82
83
84struct sti_channel {
85 struct sti_mbox_device *mdev;
86 unsigned int instance;
87 unsigned int channel;
88};
89
90static 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
100static inline
101struct 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
123static 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
138static 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
153static 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
164static 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
176 return NULL;
177
178
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
195static 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++) {
203keep_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
217static 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
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
255static 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
278static 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
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
296static 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
304static 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
320 sti_mbox_disable_channel(chan);
321 sti_mbox_clear_irq(chan);
322 chan->con_priv = NULL;
323}
324
325static 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
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
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
359
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
387static const struct mbox_chan_ops sti_mbox_ops = {
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
394static const struct sti_mbox_pdata mbox_stih407_pdata = {
395 .num_inst = 4,
396 .num_chan = 32,
397};
398
399static const struct of_device_id sti_mailbox_match[] = {
400 {
401 .compatible = "st,stih407-mailbox",
402 .data = (void *)&mbox_stih407_pdata
403 },
404 { }
405};
406MODULE_DEVICE_TABLE(of, sti_mailbox_match);
407
408static int sti_mbox_probe(struct platform_device *pdev)
409{
410 const struct of_device_id *match;
411 struct mbox_controller *mbox;
412 struct sti_mbox_device *mdev;
413 struct device_node *np = pdev->dev.of_node;
414 struct mbox_chan *chans;
415 struct resource *res;
416 int irq;
417 int ret;
418
419 match = of_match_device(sti_mailbox_match, &pdev->dev);
420 if (!match) {
421 dev_err(&pdev->dev, "No configuration found\n");
422 return -ENODEV;
423 }
424 pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data;
425
426 mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
427 if (!mdev)
428 return -ENOMEM;
429
430 platform_set_drvdata(pdev, mdev);
431
432 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
433 mdev->base = devm_ioremap_resource(&pdev->dev, res);
434 if (IS_ERR(mdev->base))
435 return PTR_ERR(mdev->base);
436
437 ret = of_property_read_string(np, "mbox-name", &mdev->name);
438 if (ret)
439 mdev->name = np->full_name;
440
441 mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
442 if (!mbox)
443 return -ENOMEM;
444
445 chans = devm_kcalloc(&pdev->dev,
446 STI_MBOX_CHAN_MAX, sizeof(*chans), GFP_KERNEL);
447 if (!chans)
448 return -ENOMEM;
449
450 mdev->dev = &pdev->dev;
451 mdev->mbox = mbox;
452
453 spin_lock_init(&mdev->lock);
454
455
456 mbox->txdone_irq = false;
457 mbox->txdone_poll = true;
458 mbox->txpoll_period = 100;
459 mbox->ops = &sti_mbox_ops;
460 mbox->dev = mdev->dev;
461 mbox->of_xlate = sti_mbox_xlate;
462 mbox->chans = chans;
463 mbox->num_chans = STI_MBOX_CHAN_MAX;
464
465 ret = devm_mbox_controller_register(&pdev->dev, mbox);
466 if (ret)
467 return ret;
468
469
470 irq = platform_get_irq(pdev, 0);
471 if (irq < 0) {
472 dev_info(&pdev->dev,
473 "%s: Registered Tx only Mailbox\n", mdev->name);
474 return 0;
475 }
476
477 ret = devm_request_threaded_irq(&pdev->dev, irq,
478 sti_mbox_irq_handler,
479 sti_mbox_thread_handler,
480 IRQF_ONESHOT, mdev->name, mdev);
481 if (ret) {
482 dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq);
483 return -EINVAL;
484 }
485
486 dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name);
487
488 return 0;
489}
490
491static struct platform_driver sti_mbox_driver = {
492 .probe = sti_mbox_probe,
493 .driver = {
494 .name = "sti-mailbox",
495 .of_match_table = sti_mailbox_match,
496 },
497};
498module_platform_driver(sti_mbox_driver);
499
500MODULE_LICENSE("GPL");
501MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller");
502MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
503MODULE_ALIAS("platform:mailbox-sti");
504
