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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015 ST Microelectronics
4 *
5 * Author: Lee Jones <lee.jones@linaro.org>
6 */
7
8#include <linux/debugfs.h>
9#include <linux/err.h>
10#include <linux/fs.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/mailbox_client.h>
14#include <linux/module.h>
15#include <linux/mutex.h>
16#include <linux/of.h>
17#include <linux/platform_device.h>
18#include <linux/poll.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21#include <linux/uaccess.h>
22#include <linux/sched/signal.h>
23
24#define MBOX_MAX_SIG_LEN 8
25#define MBOX_MAX_MSG_LEN 128
26#define MBOX_BYTES_PER_LINE 16
27#define MBOX_HEXDUMP_LINE_LEN ((MBOX_BYTES_PER_LINE * 4) + 2)
28#define MBOX_HEXDUMP_MAX_LEN (MBOX_HEXDUMP_LINE_LEN * \
29 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
30
31static bool mbox_data_ready;
32
33struct mbox_test_device {
34 struct device *dev;
35 void __iomem *tx_mmio;
36 void __iomem *rx_mmio;
37 struct mbox_chan *tx_channel;
38 struct mbox_chan *rx_channel;
39 char *rx_buffer;
40 char *signal;
41 char *message;
42 spinlock_t lock;
43 struct mutex mutex;
44 wait_queue_head_t waitq;
45 struct fasync_struct *async_queue;
46 struct dentry *root_debugfs_dir;
47};
48
49static ssize_t mbox_test_signal_write(struct file *filp,
50 const char __user *userbuf,
51 size_t count, loff_t *ppos)
52{
53 struct mbox_test_device *tdev = filp->private_data;
54
55 if (!tdev->tx_channel) {
56 dev_err(tdev->dev, "Channel cannot do Tx\n");
57 return -EINVAL;
58 }
59
60 if (count > MBOX_MAX_SIG_LEN) {
61 dev_err(tdev->dev,
62 "Signal length %zd greater than max allowed %d\n",
63 count, MBOX_MAX_SIG_LEN);
64 return -EINVAL;
65 }
66
67 /* Only allocate memory if we need to */
68 if (!tdev->signal) {
69 tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
70 if (!tdev->signal)
71 return -ENOMEM;
72 }
73
74 if (copy_from_user(tdev->signal, userbuf, count)) {
75 kfree(tdev->signal);
76 tdev->signal = NULL;
77 return -EFAULT;
78 }
79
80 return count;
81}
82
83static const struct file_operations mbox_test_signal_ops = {
84 .write = mbox_test_signal_write,
85 .open = simple_open,
86 .llseek = generic_file_llseek,
87};
88
89static int mbox_test_message_fasync(int fd, struct file *filp, int on)
90{
91 struct mbox_test_device *tdev = filp->private_data;
92
93 return fasync_helper(fd, filp, on, &tdev->async_queue);
94}
95
96static ssize_t mbox_test_message_write(struct file *filp,
97 const char __user *userbuf,
98 size_t count, loff_t *ppos)
99{
100 struct mbox_test_device *tdev = filp->private_data;
101 char *message;
102 void *data;
103 int ret;
104
105 if (!tdev->tx_channel) {
106 dev_err(tdev->dev, "Channel cannot do Tx\n");
107 return -EINVAL;
108 }
109
110 if (count > MBOX_MAX_MSG_LEN) {
111 dev_err(tdev->dev,
112 "Message length %zd greater than max allowed %d\n",
113 count, MBOX_MAX_MSG_LEN);
114 return -EINVAL;
115 }
116
117 message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
118 if (!message)
119 return -ENOMEM;
120
121 mutex_lock(&tdev->mutex);
122
123 tdev->message = message;
124 ret = copy_from_user(tdev->message, userbuf, count);
125 if (ret) {
126 ret = -EFAULT;
127 goto out;
128 }
129
130 /*
131 * A separate signal is only of use if there is
132 * MMIO to subsequently pass the message through
133 */
134 if (tdev->tx_mmio && tdev->signal) {
135 print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
136 tdev->signal, MBOX_MAX_SIG_LEN);
137
138 data = tdev->signal;
139 } else
140 data = tdev->message;
141
142 print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
143 tdev->message, MBOX_MAX_MSG_LEN);
144
145 ret = mbox_send_message(tdev->tx_channel, data);
146 if (ret < 0)
147 dev_err(tdev->dev, "Failed to send message via mailbox\n");
148
149out:
150 kfree(tdev->signal);
151 kfree(tdev->message);
152 tdev->signal = NULL;
153
154 mutex_unlock(&tdev->mutex);
155
156 return ret < 0 ? ret : count;
157}
158
159static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
160{
161 bool data_ready;
162 unsigned long flags;
163
164 spin_lock_irqsave(&tdev->lock, flags);
165 data_ready = mbox_data_ready;
166 spin_unlock_irqrestore(&tdev->lock, flags);
167
168 return data_ready;
169}
170
171static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
172 size_t count, loff_t *ppos)
173{
174 struct mbox_test_device *tdev = filp->private_data;
175 unsigned long flags;
176 char *touser, *ptr;
177 int l = 0;
178 int ret;
179
180 DECLARE_WAITQUEUE(wait, current);
181
182 touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
183 if (!touser)
184 return -ENOMEM;
185
186 if (!tdev->rx_channel) {
187 ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
188 ret = simple_read_from_buffer(userbuf, count, ppos,
189 touser, ret);
190 goto kfree_err;
191 }
192
193 add_wait_queue(&tdev->waitq, &wait);
194
195 do {
196 __set_current_state(TASK_INTERRUPTIBLE);
197
198 if (mbox_test_message_data_ready(tdev))
199 break;
200
201 if (filp->f_flags & O_NONBLOCK) {
202 ret = -EAGAIN;
203 goto waitq_err;
204 }
205
206 if (signal_pending(current)) {
207 ret = -ERESTARTSYS;
208 goto waitq_err;
209 }
210 schedule();
211
212 } while (1);
213
214 spin_lock_irqsave(&tdev->lock, flags);
215
216 ptr = tdev->rx_buffer;
217 while (l < MBOX_HEXDUMP_MAX_LEN) {
218 hex_dump_to_buffer(ptr,
219 MBOX_BYTES_PER_LINE,
220 MBOX_BYTES_PER_LINE, 1, touser + l,
221 MBOX_HEXDUMP_LINE_LEN, true);
222
223 ptr += MBOX_BYTES_PER_LINE;
224 l += MBOX_HEXDUMP_LINE_LEN;
225 *(touser + (l - 1)) = '\n';
226 }
227 *(touser + l) = '\0';
228
229 memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
230 mbox_data_ready = false;
231
232 spin_unlock_irqrestore(&tdev->lock, flags);
233
234 ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
235waitq_err:
236 __set_current_state(TASK_RUNNING);
237 remove_wait_queue(&tdev->waitq, &wait);
238kfree_err:
239 kfree(touser);
240 return ret;
241}
242
243static __poll_t
244mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
245{
246 struct mbox_test_device *tdev = filp->private_data;
247
248 poll_wait(filp, &tdev->waitq, wait);
249
250 if (mbox_test_message_data_ready(tdev))
251 return EPOLLIN | EPOLLRDNORM;
252 return 0;
253}
254
255static const struct file_operations mbox_test_message_ops = {
256 .write = mbox_test_message_write,
257 .read = mbox_test_message_read,
258 .fasync = mbox_test_message_fasync,
259 .poll = mbox_test_message_poll,
260 .open = simple_open,
261 .llseek = generic_file_llseek,
262};
263
264static int mbox_test_add_debugfs(struct platform_device *pdev,
265 struct mbox_test_device *tdev)
266{
267 if (!debugfs_initialized())
268 return 0;
269
270 tdev->root_debugfs_dir = debugfs_create_dir(dev_name(&pdev->dev), NULL);
271 if (!tdev->root_debugfs_dir) {
272 dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
273 return -EINVAL;
274 }
275
276 debugfs_create_file("message", 0600, tdev->root_debugfs_dir,
277 tdev, &mbox_test_message_ops);
278
279 debugfs_create_file("signal", 0200, tdev->root_debugfs_dir,
280 tdev, &mbox_test_signal_ops);
281
282 return 0;
283}
284
285static void mbox_test_receive_message(struct mbox_client *client, void *message)
286{
287 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
288 unsigned long flags;
289
290 spin_lock_irqsave(&tdev->lock, flags);
291 if (tdev->rx_mmio) {
292 memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
293 print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
294 tdev->rx_buffer, MBOX_MAX_MSG_LEN);
295 } else if (message) {
296 print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
297 message, MBOX_MAX_MSG_LEN);
298 memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
299 }
300 mbox_data_ready = true;
301 spin_unlock_irqrestore(&tdev->lock, flags);
302
303 wake_up_interruptible(&tdev->waitq);
304
305 kill_fasync(&tdev->async_queue, SIGIO, POLL_IN);
306}
307
308static void mbox_test_prepare_message(struct mbox_client *client, void *message)
309{
310 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
311
312 if (tdev->tx_mmio) {
313 if (tdev->signal)
314 memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
315 else
316 memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
317 }
318}
319
320static void mbox_test_message_sent(struct mbox_client *client,
321 void *message, int r)
322{
323 if (r)
324 dev_warn(client->dev,
325 "Client: Message could not be sent: %d\n", r);
326 else
327 dev_info(client->dev,
328 "Client: Message sent\n");
329}
330
331static struct mbox_chan *
332mbox_test_request_channel(struct platform_device *pdev, const char *name)
333{
334 struct mbox_client *client;
335 struct mbox_chan *channel;
336
337 client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
338 if (!client)
339 return ERR_PTR(-ENOMEM);
340
341 client->dev = &pdev->dev;
342 client->rx_callback = mbox_test_receive_message;
343 client->tx_prepare = mbox_test_prepare_message;
344 client->tx_done = mbox_test_message_sent;
345 client->tx_block = true;
346 client->knows_txdone = false;
347 client->tx_tout = 500;
348
349 channel = mbox_request_channel_byname(client, name);
350 if (IS_ERR(channel)) {
351 dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
352 return NULL;
353 }
354
355 return channel;
356}
357
358static int mbox_test_probe(struct platform_device *pdev)
359{
360 struct mbox_test_device *tdev;
361 struct resource *res;
362 resource_size_t size;
363 int ret;
364
365 tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
366 if (!tdev)
367 return -ENOMEM;
368
369 /* It's okay for MMIO to be NULL */
370 tdev->tx_mmio = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
371 if (PTR_ERR(tdev->tx_mmio) == -EBUSY) {
372 /* if reserved area in SRAM, try just ioremap */
373 size = resource_size(res);
374 tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size);
375 } else if (IS_ERR(tdev->tx_mmio)) {
376 tdev->tx_mmio = NULL;
377 }
378
379 /* If specified, second reg entry is Rx MMIO */
380 tdev->rx_mmio = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
381 if (PTR_ERR(tdev->rx_mmio) == -EBUSY) {
382 size = resource_size(res);
383 tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size);
384 } else if (IS_ERR(tdev->rx_mmio)) {
385 tdev->rx_mmio = tdev->tx_mmio;
386 }
387
388 tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
389 tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
390
391 if (IS_ERR_OR_NULL(tdev->tx_channel) && IS_ERR_OR_NULL(tdev->rx_channel))
392 return -EPROBE_DEFER;
393
394 /* If Rx is not specified but has Rx MMIO, then Rx = Tx */
395 if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
396 tdev->rx_channel = tdev->tx_channel;
397
398 tdev->dev = &pdev->dev;
399 platform_set_drvdata(pdev, tdev);
400
401 spin_lock_init(&tdev->lock);
402 mutex_init(&tdev->mutex);
403
404 if (tdev->rx_channel) {
405 tdev->rx_buffer = devm_kzalloc(&pdev->dev,
406 MBOX_MAX_MSG_LEN, GFP_KERNEL);
407 if (!tdev->rx_buffer)
408 return -ENOMEM;
409 }
410
411 ret = mbox_test_add_debugfs(pdev, tdev);
412 if (ret)
413 return ret;
414
415 init_waitqueue_head(&tdev->waitq);
416 dev_info(&pdev->dev, "Successfully registered\n");
417
418 return 0;
419}
420
421static void mbox_test_remove(struct platform_device *pdev)
422{
423 struct mbox_test_device *tdev = platform_get_drvdata(pdev);
424
425 debugfs_remove_recursive(tdev->root_debugfs_dir);
426
427 if (tdev->tx_channel)
428 mbox_free_channel(tdev->tx_channel);
429 if (tdev->rx_channel)
430 mbox_free_channel(tdev->rx_channel);
431}
432
433static const struct of_device_id mbox_test_match[] = {
434 { .compatible = "mailbox-test" },
435 {},
436};
437MODULE_DEVICE_TABLE(of, mbox_test_match);
438
439static struct platform_driver mbox_test_driver = {
440 .driver = {
441 .name = "mailbox_test",
442 .of_match_table = mbox_test_match,
443 },
444 .probe = mbox_test_probe,
445 .remove_new = mbox_test_remove,
446};
447module_platform_driver(mbox_test_driver);
448
449MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
450MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
451MODULE_LICENSE("GPL v2");
1/*
2 * Copyright (C) 2015 ST Microelectronics
3 *
4 * Author: Lee Jones <lee.jones@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/debugfs.h>
13#include <linux/err.h>
14#include <linux/fs.h>
15#include <linux/io.h>
16#include <linux/kernel.h>
17#include <linux/mailbox_client.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/platform_device.h>
21#include <linux/poll.h>
22#include <linux/slab.h>
23#include <linux/uaccess.h>
24
25#define MBOX_MAX_SIG_LEN 8
26#define MBOX_MAX_MSG_LEN 128
27#define MBOX_BYTES_PER_LINE 16
28#define MBOX_HEXDUMP_LINE_LEN ((MBOX_BYTES_PER_LINE * 4) + 2)
29#define MBOX_HEXDUMP_MAX_LEN (MBOX_HEXDUMP_LINE_LEN * \
30 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
31
32static struct dentry *root_debugfs_dir;
33
34struct mbox_test_device {
35 struct device *dev;
36 void __iomem *tx_mmio;
37 void __iomem *rx_mmio;
38 struct mbox_chan *tx_channel;
39 struct mbox_chan *rx_channel;
40 char *rx_buffer;
41 char *signal;
42 char *message;
43 spinlock_t lock;
44 wait_queue_head_t waitq;
45 struct fasync_struct *async_queue;
46};
47
48static ssize_t mbox_test_signal_write(struct file *filp,
49 const char __user *userbuf,
50 size_t count, loff_t *ppos)
51{
52 struct mbox_test_device *tdev = filp->private_data;
53
54 if (!tdev->tx_channel) {
55 dev_err(tdev->dev, "Channel cannot do Tx\n");
56 return -EINVAL;
57 }
58
59 if (count > MBOX_MAX_SIG_LEN) {
60 dev_err(tdev->dev,
61 "Signal length %zd greater than max allowed %d\n",
62 count, MBOX_MAX_SIG_LEN);
63 return -EINVAL;
64 }
65
66 /* Only allocate memory if we need to */
67 if (!tdev->signal) {
68 tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
69 if (!tdev->signal)
70 return -ENOMEM;
71 }
72
73 if (copy_from_user(tdev->signal, userbuf, count)) {
74 kfree(tdev->signal);
75 tdev->signal = NULL;
76 return -EFAULT;
77 }
78
79 return count;
80}
81
82static const struct file_operations mbox_test_signal_ops = {
83 .write = mbox_test_signal_write,
84 .open = simple_open,
85 .llseek = generic_file_llseek,
86};
87
88static int mbox_test_message_fasync(int fd, struct file *filp, int on)
89{
90 struct mbox_test_device *tdev = filp->private_data;
91
92 return fasync_helper(fd, filp, on, &tdev->async_queue);
93}
94
95static ssize_t mbox_test_message_write(struct file *filp,
96 const char __user *userbuf,
97 size_t count, loff_t *ppos)
98{
99 struct mbox_test_device *tdev = filp->private_data;
100 void *data;
101 int ret;
102
103 if (!tdev->tx_channel) {
104 dev_err(tdev->dev, "Channel cannot do Tx\n");
105 return -EINVAL;
106 }
107
108 if (count > MBOX_MAX_MSG_LEN) {
109 dev_err(tdev->dev,
110 "Message length %zd greater than max allowed %d\n",
111 count, MBOX_MAX_MSG_LEN);
112 return -EINVAL;
113 }
114
115 tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
116 if (!tdev->message)
117 return -ENOMEM;
118
119 ret = copy_from_user(tdev->message, userbuf, count);
120 if (ret) {
121 ret = -EFAULT;
122 goto out;
123 }
124
125 /*
126 * A separate signal is only of use if there is
127 * MMIO to subsequently pass the message through
128 */
129 if (tdev->tx_mmio && tdev->signal) {
130 print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
131 tdev->signal, MBOX_MAX_SIG_LEN);
132
133 data = tdev->signal;
134 } else
135 data = tdev->message;
136
137 print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
138 tdev->message, MBOX_MAX_MSG_LEN);
139
140 ret = mbox_send_message(tdev->tx_channel, data);
141 if (ret < 0)
142 dev_err(tdev->dev, "Failed to send message via mailbox\n");
143
144out:
145 kfree(tdev->signal);
146 kfree(tdev->message);
147 tdev->signal = NULL;
148
149 return ret < 0 ? ret : count;
150}
151
152static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
153{
154 unsigned char data;
155 unsigned long flags;
156
157 spin_lock_irqsave(&tdev->lock, flags);
158 data = tdev->rx_buffer[0];
159 spin_unlock_irqrestore(&tdev->lock, flags);
160
161 if (data != '\0')
162 return true;
163 return false;
164}
165
166static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
167 size_t count, loff_t *ppos)
168{
169 struct mbox_test_device *tdev = filp->private_data;
170 unsigned long flags;
171 char *touser, *ptr;
172 int l = 0;
173 int ret;
174
175 DECLARE_WAITQUEUE(wait, current);
176
177 touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
178 if (!touser)
179 return -ENOMEM;
180
181 if (!tdev->rx_channel) {
182 ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
183 ret = simple_read_from_buffer(userbuf, count, ppos,
184 touser, ret);
185 goto kfree_err;
186 }
187
188 add_wait_queue(&tdev->waitq, &wait);
189
190 do {
191 __set_current_state(TASK_INTERRUPTIBLE);
192
193 if (mbox_test_message_data_ready(tdev))
194 break;
195
196 if (filp->f_flags & O_NONBLOCK) {
197 ret = -EAGAIN;
198 goto waitq_err;
199 }
200
201 if (signal_pending(current)) {
202 ret = -ERESTARTSYS;
203 goto waitq_err;
204 }
205 schedule();
206
207 } while (1);
208
209 spin_lock_irqsave(&tdev->lock, flags);
210
211 ptr = tdev->rx_buffer;
212 while (l < MBOX_HEXDUMP_MAX_LEN) {
213 hex_dump_to_buffer(ptr,
214 MBOX_BYTES_PER_LINE,
215 MBOX_BYTES_PER_LINE, 1, touser + l,
216 MBOX_HEXDUMP_LINE_LEN, true);
217
218 ptr += MBOX_BYTES_PER_LINE;
219 l += MBOX_HEXDUMP_LINE_LEN;
220 *(touser + (l - 1)) = '\n';
221 }
222 *(touser + l) = '\0';
223
224 memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
225
226 spin_unlock_irqrestore(&tdev->lock, flags);
227
228 ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
229waitq_err:
230 __set_current_state(TASK_RUNNING);
231 remove_wait_queue(&tdev->waitq, &wait);
232kfree_err:
233 kfree(touser);
234 return ret;
235}
236
237static unsigned int
238mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
239{
240 struct mbox_test_device *tdev = filp->private_data;
241
242 poll_wait(filp, &tdev->waitq, wait);
243
244 if (mbox_test_message_data_ready(tdev))
245 return POLLIN | POLLRDNORM;
246 return 0;
247}
248
249static const struct file_operations mbox_test_message_ops = {
250 .write = mbox_test_message_write,
251 .read = mbox_test_message_read,
252 .fasync = mbox_test_message_fasync,
253 .poll = mbox_test_message_poll,
254 .open = simple_open,
255 .llseek = generic_file_llseek,
256};
257
258static int mbox_test_add_debugfs(struct platform_device *pdev,
259 struct mbox_test_device *tdev)
260{
261 if (!debugfs_initialized())
262 return 0;
263
264 root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
265 if (!root_debugfs_dir) {
266 dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
267 return -EINVAL;
268 }
269
270 debugfs_create_file("message", 0600, root_debugfs_dir,
271 tdev, &mbox_test_message_ops);
272
273 debugfs_create_file("signal", 0200, root_debugfs_dir,
274 tdev, &mbox_test_signal_ops);
275
276 return 0;
277}
278
279static void mbox_test_receive_message(struct mbox_client *client, void *message)
280{
281 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
282 unsigned long flags;
283
284 spin_lock_irqsave(&tdev->lock, flags);
285 if (tdev->rx_mmio) {
286 memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
287 print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
288 tdev->rx_buffer, MBOX_MAX_MSG_LEN);
289 } else if (message) {
290 print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
291 message, MBOX_MAX_MSG_LEN);
292 memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
293 }
294 spin_unlock_irqrestore(&tdev->lock, flags);
295
296 wake_up_interruptible(&tdev->waitq);
297
298 kill_fasync(&tdev->async_queue, SIGIO, POLL_IN);
299}
300
301static void mbox_test_prepare_message(struct mbox_client *client, void *message)
302{
303 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
304
305 if (tdev->tx_mmio) {
306 if (tdev->signal)
307 memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
308 else
309 memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
310 }
311}
312
313static void mbox_test_message_sent(struct mbox_client *client,
314 void *message, int r)
315{
316 if (r)
317 dev_warn(client->dev,
318 "Client: Message could not be sent: %d\n", r);
319 else
320 dev_info(client->dev,
321 "Client: Message sent\n");
322}
323
324static struct mbox_chan *
325mbox_test_request_channel(struct platform_device *pdev, const char *name)
326{
327 struct mbox_client *client;
328 struct mbox_chan *channel;
329
330 client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
331 if (!client)
332 return ERR_PTR(-ENOMEM);
333
334 client->dev = &pdev->dev;
335 client->rx_callback = mbox_test_receive_message;
336 client->tx_prepare = mbox_test_prepare_message;
337 client->tx_done = mbox_test_message_sent;
338 client->tx_block = true;
339 client->knows_txdone = false;
340 client->tx_tout = 500;
341
342 channel = mbox_request_channel_byname(client, name);
343 if (IS_ERR(channel)) {
344 dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
345 return NULL;
346 }
347
348 return channel;
349}
350
351static int mbox_test_probe(struct platform_device *pdev)
352{
353 struct mbox_test_device *tdev;
354 struct resource *res;
355 resource_size_t size;
356 int ret;
357
358 tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
359 if (!tdev)
360 return -ENOMEM;
361
362 /* It's okay for MMIO to be NULL */
363 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
364 size = resource_size(res);
365 tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
366 if (PTR_ERR(tdev->tx_mmio) == -EBUSY)
367 /* if reserved area in SRAM, try just ioremap */
368 tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size);
369 else if (IS_ERR(tdev->tx_mmio))
370 tdev->tx_mmio = NULL;
371
372 /* If specified, second reg entry is Rx MMIO */
373 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
374 size = resource_size(res);
375 tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
376 if (PTR_ERR(tdev->rx_mmio) == -EBUSY)
377 tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size);
378 else if (IS_ERR(tdev->rx_mmio))
379 tdev->rx_mmio = tdev->tx_mmio;
380
381 tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
382 tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
383
384 if (!tdev->tx_channel && !tdev->rx_channel)
385 return -EPROBE_DEFER;
386
387 /* If Rx is not specified but has Rx MMIO, then Rx = Tx */
388 if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
389 tdev->rx_channel = tdev->tx_channel;
390
391 tdev->dev = &pdev->dev;
392 platform_set_drvdata(pdev, tdev);
393
394 spin_lock_init(&tdev->lock);
395
396 if (tdev->rx_channel) {
397 tdev->rx_buffer = devm_kzalloc(&pdev->dev,
398 MBOX_MAX_MSG_LEN, GFP_KERNEL);
399 if (!tdev->rx_buffer)
400 return -ENOMEM;
401 }
402
403 ret = mbox_test_add_debugfs(pdev, tdev);
404 if (ret)
405 return ret;
406
407 init_waitqueue_head(&tdev->waitq);
408 dev_info(&pdev->dev, "Successfully registered\n");
409
410 return 0;
411}
412
413static int mbox_test_remove(struct platform_device *pdev)
414{
415 struct mbox_test_device *tdev = platform_get_drvdata(pdev);
416
417 debugfs_remove_recursive(root_debugfs_dir);
418
419 if (tdev->tx_channel)
420 mbox_free_channel(tdev->tx_channel);
421 if (tdev->rx_channel)
422 mbox_free_channel(tdev->rx_channel);
423
424 return 0;
425}
426
427static const struct of_device_id mbox_test_match[] = {
428 { .compatible = "mailbox-test" },
429 {},
430};
431MODULE_DEVICE_TABLE(of, mbox_test_match);
432
433static struct platform_driver mbox_test_driver = {
434 .driver = {
435 .name = "mailbox_test",
436 .of_match_table = mbox_test_match,
437 },
438 .probe = mbox_test_probe,
439 .remove = mbox_test_remove,
440};
441module_platform_driver(mbox_test_driver);
442
443MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
444MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
445MODULE_LICENSE("GPL v2");