aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mailbox/hi6220-mailbox.c
blob: 519376d3534cfa05d623819b4ceb3f5a398e0cf3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/*
 * Hisilicon's Hi6220 mailbox driver
 *
 * Copyright (c) 2015 Hisilicon Limited.
 * Copyright (c) 2015 Linaro Limited.
 *
 * Author: Leo Yan <leo.yan@linaro.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kfifo.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#define MBOX_CHAN_MAX			32

#define MBOX_TX				0x1

/* Mailbox message length: 8 words */
#define MBOX_MSG_LEN			8

/* Mailbox Registers */
#define MBOX_OFF(m)			(0x40 * (m))
#define MBOX_MODE_REG(m)		(MBOX_OFF(m) + 0x0)
#define MBOX_DATA_REG(m)		(MBOX_OFF(m) + 0x4)

#define MBOX_STATE_MASK			(0xF << 4)
#define MBOX_STATE_IDLE			(0x1 << 4)
#define MBOX_STATE_TX			(0x2 << 4)
#define MBOX_STATE_RX			(0x4 << 4)
#define MBOX_STATE_ACK			(0x8 << 4)
#define MBOX_ACK_CONFIG_MASK		(0x1 << 0)
#define MBOX_ACK_AUTOMATIC		(0x1 << 0)
#define MBOX_ACK_IRQ			(0x0 << 0)

/* IPC registers */
#define ACK_INT_RAW_REG(i)		((i) + 0x400)
#define ACK_INT_MSK_REG(i)		((i) + 0x404)
#define ACK_INT_STAT_REG(i)		((i) + 0x408)
#define ACK_INT_CLR_REG(i)		((i) + 0x40c)
#define ACK_INT_ENA_REG(i)		((i) + 0x500)
#define ACK_INT_DIS_REG(i)		((i) + 0x504)
#define DST_INT_RAW_REG(i)		((i) + 0x420)


struct hi6220_mbox_chan {

	/*
	 * Description for channel's hardware info:
	 *  - direction: tx or rx
	 *  - dst irq: peer core's irq number
	 *  - ack irq: local irq number
	 *  - slot number
	 */
	unsigned int dir, dst_irq, ack_irq;
	unsigned int slot;

	struct hi6220_mbox *parent;
};

struct hi6220_mbox {
	struct device *dev;

	int irq;

	/* flag of enabling tx's irq mode */
	bool tx_irq_mode;

	/* region for ipc event */
	void __iomem *ipc;

	/* region for mailbox */
	void __iomem *base;

	unsigned int chan_num;
	struct hi6220_mbox_chan *mchan;

	void *irq_map_chan[MBOX_CHAN_MAX];
	struct mbox_chan *chan;
	struct mbox_controller controller;
};

static void mbox_set_state(struct hi6220_mbox *mbox,
			   unsigned int slot, u32 val)
{
	u32 status;

	status = readl(mbox->base + MBOX_MODE_REG(slot));
	status = (status & ~MBOX_STATE_MASK) | val;
	writel(status, mbox->base + MBOX_MODE_REG(slot));
}

static void mbox_set_mode(struct hi6220_mbox *mbox,
			  unsigned int slot, u32 val)
{
	u32 mode;

	mode = readl(mbox->base + MBOX_MODE_REG(slot));
	mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
	writel(mode, mbox->base + MBOX_MODE_REG(slot));
}

static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
{
	struct hi6220_mbox_chan *mchan = chan->con_priv;
	struct hi6220_mbox *mbox = mchan->parent;
	u32 state;

	/* Only set idle state for polling mode */
	BUG_ON(mbox->tx_irq_mode);

	state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
	return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
}

static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
{
	struct hi6220_mbox_chan *mchan = chan->con_priv;
	struct hi6220_mbox *mbox = mchan->parent;
	unsigned int slot = mchan->slot;
	u32 *buf = msg;
	int i;

	/* indicate as a TX channel */
	mchan->dir = MBOX_TX;

	mbox_set_state(mbox, slot, MBOX_STATE_TX);

	if (mbox->tx_irq_mode)
		mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
	else
		mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);

	for (i = 0; i < MBOX_MSG_LEN; i++)
		writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);

	/* trigger remote request */
	writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
	return 0;
}

static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
{
	struct hi6220_mbox *mbox = p;
	struct hi6220_mbox_chan *mchan;
	struct mbox_chan *chan;
	unsigned int state, intr_bit, i;
	u32 msg[MBOX_MSG_LEN];

	state = readl(ACK_INT_STAT_REG(mbox->ipc));
	if (!state) {
		dev_warn(mbox->dev, "%s: spurious interrupt\n",
			 __func__);
		return IRQ_HANDLED;
	}

	while (state) {
		intr_bit = __ffs(state);
		state &= (state - 1);

		chan = mbox->irq_map_chan[intr_bit];
		if (!chan) {
			dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
				 __func__, intr_bit);
			continue;
		}

		mchan = chan->con_priv;
		if (mchan->dir == MBOX_TX)
			mbox_chan_txdone(chan, 0);
		else {
			for (i = 0; i < MBOX_MSG_LEN; i++)
				msg[i] = readl(mbox->base +
					MBOX_DATA_REG(mchan->slot) + i * 4);

			mbox_chan_received_data(chan, (void *)msg);
		}

		/* clear IRQ source */
		writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
		mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
	}

	return IRQ_HANDLED;
}

static int hi6220_mbox_startup(struct mbox_chan *chan)
{
	struct hi6220_mbox_chan *mchan = chan->con_priv;
	struct hi6220_mbox *mbox = mchan->parent;

	mchan->dir = 0;

	/* enable interrupt */
	writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
	return 0;
}

static void hi6220_mbox_shutdown(struct mbox_chan *chan)
{
	struct hi6220_mbox_chan *mchan = chan->con_priv;
	struct hi6220_mbox *mbox = mchan->parent;

	/* disable interrupt */
	writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
	mbox->irq_map_chan[mchan->ack_irq] = NULL;
}

static const struct mbox_chan_ops hi6220_mbox_ops = {
	.send_data    = hi6220_mbox_send_data,
	.startup      = hi6220_mbox_startup,
	.shutdown     = hi6220_mbox_shutdown,
	.last_tx_done = hi6220_mbox_last_tx_done,
};

static struct mbox_chan *hi6220_mbox_xlate(struct mbox_controller *controller,
					   const struct of_phandle_args *spec)
{
	struct hi6220_mbox *mbox = dev_get_drvdata(controller->dev);
	struct hi6220_mbox_chan *mchan;
	struct mbox_chan *chan;
	unsigned int i = spec->args[0];
	unsigned int dst_irq = spec->args[1];
	unsigned int ack_irq = spec->args[2];

	/* Bounds checking */
	if (i >= mbox->chan_num || dst_irq >= mbox->chan_num ||
	    ack_irq >= mbox->chan_num) {
		dev_err(mbox->dev,
			"Invalid channel idx %d dst_irq %d ack_irq %d\n",
			i, dst_irq, ack_irq);
		return ERR_PTR(-EINVAL);
	}

	/* Is requested channel free? */
	chan = &mbox->chan[i];
	if (mbox->irq_map_chan[ack_irq] == (void *)chan) {
		dev_err(mbox->dev, "Channel in use\n");
		return ERR_PTR(-EBUSY);
	}

	mchan = chan->con_priv;
	mchan->dst_irq = dst_irq;
	mchan->ack_irq = ack_irq;

	mbox->irq_map_chan[ack_irq] = (void *)chan;
	return chan;
}

static const struct of_device_id hi6220_mbox_of_match[] = {
	{ .compatible = "hisilicon,hi6220-mbox", },
	{},
};
MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);

static int hi6220_mbox_probe(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	struct device *dev = &pdev->dev;
	struct hi6220_mbox *mbox;
	struct resource *res;
	int i, err;

	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
	if (!mbox)
		return -ENOMEM;

	mbox->dev = dev;
	mbox->chan_num = MBOX_CHAN_MAX;
	mbox->mchan = devm_kzalloc(dev,
		mbox->chan_num * sizeof(*mbox->mchan), GFP_KERNEL);
	if (!mbox->mchan)
		return -ENOMEM;

	mbox->chan = devm_kzalloc(dev,
		mbox->chan_num * sizeof(*mbox->chan), GFP_KERNEL);
	if (!mbox->chan)
		return -ENOMEM;

	mbox->irq = platform_get_irq(pdev, 0);
	if (mbox->irq < 0)
		return mbox->irq;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	mbox->ipc = devm_ioremap_resource(dev, res);
	if (IS_ERR(mbox->ipc)) {
		dev_err(dev, "ioremap ipc failed\n");
		return PTR_ERR(mbox->ipc);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	mbox->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(mbox->base)) {
		dev_err(dev, "ioremap buffer failed\n");
		return PTR_ERR(mbox->base);
	}

	err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
			dev_name(dev), mbox);
	if (err) {
		dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
			err);
		return -ENODEV;
	}

	mbox->controller.dev = dev;
	mbox->controller.chans = &mbox->chan[0];
	mbox->controller.num_chans = mbox->chan_num;
	mbox->controller.ops = &hi6220_mbox_ops;
	mbox->controller.of_xlate = hi6220_mbox_xlate;

	for (i = 0; i < mbox->chan_num; i++) {
		mbox->chan[i].con_priv = &mbox->mchan[i];
		mbox->irq_map_chan[i] = NULL;

		mbox->mchan[i].parent = mbox;
		mbox->mchan[i].slot   = i;
	}

	/* mask and clear all interrupt vectors */
	writel(0x0,  ACK_INT_MSK_REG(mbox->ipc));
	writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));

	/* use interrupt for tx's ack */
	if (of_find_property(node, "hi6220,mbox-tx-noirq", NULL))
		mbox->tx_irq_mode = false;
	else
		mbox->tx_irq_mode = true;

	if (mbox->tx_irq_mode)
		mbox->controller.txdone_irq = true;
	else {
		mbox->controller.txdone_poll = true;
		mbox->controller.txpoll_period = 5;
	}

	err = mbox_controller_register(&mbox->controller);
	if (err) {
		dev_err(dev, "Failed to register mailbox %d\n", err);
		return err;
	}

	platform_set_drvdata(pdev, mbox);
	dev_info(dev, "Mailbox enabled\n");
	return 0;
}

static int hi6220_mbox_remove(struct platform_device *pdev)
{
	struct hi6220_mbox *mbox = platform_get_drvdata(pdev);

	mbox_controller_unregister(&mbox->controller);
	return 0;
}

static struct platform_driver hi6220_mbox_driver = {
	.driver = {
		.name = "hi6220-mbox",
		.owner = THIS_MODULE,
		.of_match_table = hi6220_mbox_of_match,
	},
	.probe	= hi6220_mbox_probe,
	.remove	= hi6220_mbox_remove,
};

static int __init hi6220_mbox_init(void)
{
	return platform_driver_register(&hi6220_mbox_driver);
}
core_initcall(hi6220_mbox_init);

static void __exit hi6220_mbox_exit(void)
{
	platform_driver_unregister(&hi6220_mbox_driver);
}
module_exit(hi6220_mbox_exit);

MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
MODULE_DESCRIPTION("Hi6220 mailbox driver");
MODULE_LICENSE("GPL v2");

Privacy Policy