xref: /linux/drivers/mailbox/hi6220-mailbox.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e) 
1 /*
2  * Hisilicon's Hi6220 mailbox driver
3  *
4  * Copyright (c) 2015 Hisilicon Limited.
5  * Copyright (c) 2015 Linaro Limited.
6  *
7  * Author: Leo Yan <leo.yan@linaro.org>
8  *
9  * This program is free software: you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation, version 2 of the License.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  */
19 
20 #include <linux/device.h>
21 #include <linux/err.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/kfifo.h>
25 #include <linux/mailbox_controller.h>
26 #include <linux/module.h>
27 #include <linux/platform_device.h>
28 #include <linux/slab.h>
29 
30 #define MBOX_CHAN_MAX			32
31 
32 #define MBOX_TX				0x1
33 
34 /* Mailbox message length: 8 words */
35 #define MBOX_MSG_LEN			8
36 
37 /* Mailbox Registers */
38 #define MBOX_OFF(m)			(0x40 * (m))
39 #define MBOX_MODE_REG(m)		(MBOX_OFF(m) + 0x0)
40 #define MBOX_DATA_REG(m)		(MBOX_OFF(m) + 0x4)
41 
42 #define MBOX_STATE_MASK			(0xF << 4)
43 #define MBOX_STATE_IDLE			(0x1 << 4)
44 #define MBOX_STATE_TX			(0x2 << 4)
45 #define MBOX_STATE_RX			(0x4 << 4)
46 #define MBOX_STATE_ACK			(0x8 << 4)
47 #define MBOX_ACK_CONFIG_MASK		(0x1 << 0)
48 #define MBOX_ACK_AUTOMATIC		(0x1 << 0)
49 #define MBOX_ACK_IRQ			(0x0 << 0)
50 
51 /* IPC registers */
52 #define ACK_INT_RAW_REG(i)		((i) + 0x400)
53 #define ACK_INT_MSK_REG(i)		((i) + 0x404)
54 #define ACK_INT_STAT_REG(i)		((i) + 0x408)
55 #define ACK_INT_CLR_REG(i)		((i) + 0x40c)
56 #define ACK_INT_ENA_REG(i)		((i) + 0x500)
57 #define ACK_INT_DIS_REG(i)		((i) + 0x504)
58 #define DST_INT_RAW_REG(i)		((i) + 0x420)
59 
60 
61 struct hi6220_mbox_chan {
62 
63 	/*
64 	 * Description for channel's hardware info:
65 	 *  - direction: tx or rx
66 	 *  - dst irq: peer core's irq number
67 	 *  - ack irq: local irq number
68 	 *  - slot number
69 	 */
70 	unsigned int dir, dst_irq, ack_irq;
71 	unsigned int slot;
72 
73 	struct hi6220_mbox *parent;
74 };
75 
76 struct hi6220_mbox {
77 	struct device *dev;
78 
79 	int irq;
80 
81 	/* flag of enabling tx's irq mode */
82 	bool tx_irq_mode;
83 
84 	/* region for ipc event */
85 	void __iomem *ipc;
86 
87 	/* region for mailbox */
88 	void __iomem *base;
89 
90 	unsigned int chan_num;
91 	struct hi6220_mbox_chan *mchan;
92 
93 	void *irq_map_chan[MBOX_CHAN_MAX];
94 	struct mbox_chan *chan;
95 	struct mbox_controller controller;
96 };
97 
98 static void mbox_set_state(struct hi6220_mbox *mbox,
99 			   unsigned int slot, u32 val)
100 {
101 	u32 status;
102 
103 	status = readl(mbox->base + MBOX_MODE_REG(slot));
104 	status = (status & ~MBOX_STATE_MASK) | val;
105 	writel(status, mbox->base + MBOX_MODE_REG(slot));
106 }
107 
108 static void mbox_set_mode(struct hi6220_mbox *mbox,
109 			  unsigned int slot, u32 val)
110 {
111 	u32 mode;
112 
113 	mode = readl(mbox->base + MBOX_MODE_REG(slot));
114 	mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
115 	writel(mode, mbox->base + MBOX_MODE_REG(slot));
116 }
117 
118 static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
119 {
120 	struct hi6220_mbox_chan *mchan = chan->con_priv;
121 	struct hi6220_mbox *mbox = mchan->parent;
122 	u32 state;
123 
124 	/* Only set idle state for polling mode */
125 	BUG_ON(mbox->tx_irq_mode);
126 
127 	state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
128 	return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
129 }
130 
131 static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
132 {
133 	struct hi6220_mbox_chan *mchan = chan->con_priv;
134 	struct hi6220_mbox *mbox = mchan->parent;
135 	unsigned int slot = mchan->slot;
136 	u32 *buf = msg;
137 	int i;
138 
139 	/* indicate as a TX channel */
140 	mchan->dir = MBOX_TX;
141 
142 	mbox_set_state(mbox, slot, MBOX_STATE_TX);
143 
144 	if (mbox->tx_irq_mode)
145 		mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
146 	else
147 		mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);
148 
149 	for (i = 0; i < MBOX_MSG_LEN; i++)
150 		writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);
151 
152 	/* trigger remote request */
153 	writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
154 	return 0;
155 }
156 
157 static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
158 {
159 	struct hi6220_mbox *mbox = p;
160 	struct hi6220_mbox_chan *mchan;
161 	struct mbox_chan *chan;
162 	unsigned int state, intr_bit, i;
163 	u32 msg[MBOX_MSG_LEN];
164 
165 	state = readl(ACK_INT_STAT_REG(mbox->ipc));
166 	if (!state) {
167 		dev_warn(mbox->dev, "%s: spurious interrupt\n",
168 			 __func__);
169 		return IRQ_HANDLED;
170 	}
171 
172 	while (state) {
173 		intr_bit = __ffs(state);
174 		state &= (state - 1);
175 
176 		chan = mbox->irq_map_chan[intr_bit];
177 		if (!chan) {
178 			dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
179 				 __func__, intr_bit);
180 			continue;
181 		}
182 
183 		mchan = chan->con_priv;
184 		if (mchan->dir == MBOX_TX)
185 			mbox_chan_txdone(chan, 0);
186 		else {
187 			for (i = 0; i < MBOX_MSG_LEN; i++)
188 				msg[i] = readl(mbox->base +
189 					MBOX_DATA_REG(mchan->slot) + i * 4);
190 
191 			mbox_chan_received_data(chan, (void *)msg);
192 		}
193 
194 		/* clear IRQ source */
195 		writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
196 		mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
197 	}
198 
199 	return IRQ_HANDLED;
200 }
201 
202 static int hi6220_mbox_startup(struct mbox_chan *chan)
203 {
204 	struct hi6220_mbox_chan *mchan = chan->con_priv;
205 	struct hi6220_mbox *mbox = mchan->parent;
206 
207 	mchan->dir = 0;
208 
209 	/* enable interrupt */
210 	writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
211 	return 0;
212 }
213 
214 static void hi6220_mbox_shutdown(struct mbox_chan *chan)
215 {
216 	struct hi6220_mbox_chan *mchan = chan->con_priv;
217 	struct hi6220_mbox *mbox = mchan->parent;
218 
219 	/* disable interrupt */
220 	writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
221 	mbox->irq_map_chan[mchan->ack_irq] = NULL;
222 }
223 
224 static const struct mbox_chan_ops hi6220_mbox_ops = {
225 	.send_data    = hi6220_mbox_send_data,
226 	.startup      = hi6220_mbox_startup,
227 	.shutdown     = hi6220_mbox_shutdown,
228 	.last_tx_done = hi6220_mbox_last_tx_done,
229 };
230 
231 static struct mbox_chan *hi6220_mbox_xlate(struct mbox_controller *controller,
232 					   const struct of_phandle_args *spec)
233 {
234 	struct hi6220_mbox *mbox = dev_get_drvdata(controller->dev);
235 	struct hi6220_mbox_chan *mchan;
236 	struct mbox_chan *chan;
237 	unsigned int i = spec->args[0];
238 	unsigned int dst_irq = spec->args[1];
239 	unsigned int ack_irq = spec->args[2];
240 
241 	/* Bounds checking */
242 	if (i >= mbox->chan_num || dst_irq >= mbox->chan_num ||
243 	    ack_irq >= mbox->chan_num) {
244 		dev_err(mbox->dev,
245 			"Invalid channel idx %d dst_irq %d ack_irq %d\n",
246 			i, dst_irq, ack_irq);
247 		return ERR_PTR(-EINVAL);
248 	}
249 
250 	/* Is requested channel free? */
251 	chan = &mbox->chan[i];
252 	if (mbox->irq_map_chan[ack_irq] == (void *)chan) {
253 		dev_err(mbox->dev, "Channel in use\n");
254 		return ERR_PTR(-EBUSY);
255 	}
256 
257 	mchan = chan->con_priv;
258 	mchan->dst_irq = dst_irq;
259 	mchan->ack_irq = ack_irq;
260 
261 	mbox->irq_map_chan[ack_irq] = (void *)chan;
262 	return chan;
263 }
264 
265 static const struct of_device_id hi6220_mbox_of_match[] = {
266 	{ .compatible = "hisilicon,hi6220-mbox", },
267 	{},
268 };
269 MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);
270 
271 static int hi6220_mbox_probe(struct platform_device *pdev)
272 {
273 	struct device_node *node = pdev->dev.of_node;
274 	struct device *dev = &pdev->dev;
275 	struct hi6220_mbox *mbox;
276 	struct resource *res;
277 	int i, err;
278 
279 	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
280 	if (!mbox)
281 		return -ENOMEM;
282 
283 	mbox->dev = dev;
284 	mbox->chan_num = MBOX_CHAN_MAX;
285 	mbox->mchan = devm_kcalloc(dev,
286 		mbox->chan_num, sizeof(*mbox->mchan), GFP_KERNEL);
287 	if (!mbox->mchan)
288 		return -ENOMEM;
289 
290 	mbox->chan = devm_kcalloc(dev,
291 		mbox->chan_num, sizeof(*mbox->chan), GFP_KERNEL);
292 	if (!mbox->chan)
293 		return -ENOMEM;
294 
295 	mbox->irq = platform_get_irq(pdev, 0);
296 	if (mbox->irq < 0)
297 		return mbox->irq;
298 
299 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
300 	mbox->ipc = devm_ioremap_resource(dev, res);
301 	if (IS_ERR(mbox->ipc)) {
302 		dev_err(dev, "ioremap ipc failed\n");
303 		return PTR_ERR(mbox->ipc);
304 	}
305 
306 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
307 	mbox->base = devm_ioremap_resource(dev, res);
308 	if (IS_ERR(mbox->base)) {
309 		dev_err(dev, "ioremap buffer failed\n");
310 		return PTR_ERR(mbox->base);
311 	}
312 
313 	err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
314 			dev_name(dev), mbox);
315 	if (err) {
316 		dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
317 			err);
318 		return -ENODEV;
319 	}
320 
321 	mbox->controller.dev = dev;
322 	mbox->controller.chans = &mbox->chan[0];
323 	mbox->controller.num_chans = mbox->chan_num;
324 	mbox->controller.ops = &hi6220_mbox_ops;
325 	mbox->controller.of_xlate = hi6220_mbox_xlate;
326 
327 	for (i = 0; i < mbox->chan_num; i++) {
328 		mbox->chan[i].con_priv = &mbox->mchan[i];
329 		mbox->irq_map_chan[i] = NULL;
330 
331 		mbox->mchan[i].parent = mbox;
332 		mbox->mchan[i].slot   = i;
333 	}
334 
335 	/* mask and clear all interrupt vectors */
336 	writel(0x0,  ACK_INT_MSK_REG(mbox->ipc));
337 	writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
338 
339 	/* use interrupt for tx's ack */
340 	if (of_find_property(node, "hi6220,mbox-tx-noirq", NULL))
341 		mbox->tx_irq_mode = false;
342 	else
343 		mbox->tx_irq_mode = true;
344 
345 	if (mbox->tx_irq_mode)
346 		mbox->controller.txdone_irq = true;
347 	else {
348 		mbox->controller.txdone_poll = true;
349 		mbox->controller.txpoll_period = 5;
350 	}
351 
352 	err = mbox_controller_register(&mbox->controller);
353 	if (err) {
354 		dev_err(dev, "Failed to register mailbox %d\n", err);
355 		return err;
356 	}
357 
358 	platform_set_drvdata(pdev, mbox);
359 	dev_info(dev, "Mailbox enabled\n");
360 	return 0;
361 }
362 
363 static int hi6220_mbox_remove(struct platform_device *pdev)
364 {
365 	struct hi6220_mbox *mbox = platform_get_drvdata(pdev);
366 
367 	mbox_controller_unregister(&mbox->controller);
368 	return 0;
369 }
370 
371 static struct platform_driver hi6220_mbox_driver = {
372 	.driver = {
373 		.name = "hi6220-mbox",
374 		.owner = THIS_MODULE,
375 		.of_match_table = hi6220_mbox_of_match,
376 	},
377 	.probe	= hi6220_mbox_probe,
378 	.remove	= hi6220_mbox_remove,
379 };
380 
381 static int __init hi6220_mbox_init(void)
382 {
383 	return platform_driver_register(&hi6220_mbox_driver);
384 }
385 core_initcall(hi6220_mbox_init);
386 
387 static void __exit hi6220_mbox_exit(void)
388 {
389 	platform_driver_unregister(&hi6220_mbox_driver);
390 }
391 module_exit(hi6220_mbox_exit);
392 
393 MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
394 MODULE_DESCRIPTION("Hi6220 mailbox driver");
395 MODULE_LICENSE("GPL v2");
396