Loading...
Note: File does not exist in v3.15.
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/io.h>
15#include <linux/kernel.h>
16#include <linux/mailbox_client.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/slab.h>
21#include <linux/uaccess.h>
22
23#define MBOX_MAX_SIG_LEN 8
24#define MBOX_MAX_MSG_LEN 128
25#define MBOX_BYTES_PER_LINE 16
26#define MBOX_HEXDUMP_LINE_LEN ((MBOX_BYTES_PER_LINE * 4) + 2)
27#define MBOX_HEXDUMP_MAX_LEN (MBOX_HEXDUMP_LINE_LEN * \
28 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
29
30static struct dentry *root_debugfs_dir;
31
32struct mbox_test_device {
33 struct device *dev;
34 void __iomem *tx_mmio;
35 void __iomem *rx_mmio;
36 struct mbox_chan *tx_channel;
37 struct mbox_chan *rx_channel;
38 char *rx_buffer;
39 char *signal;
40 char *message;
41 spinlock_t lock;
42};
43
44static ssize_t mbox_test_signal_write(struct file *filp,
45 const char __user *userbuf,
46 size_t count, loff_t *ppos)
47{
48 struct mbox_test_device *tdev = filp->private_data;
49
50 if (!tdev->tx_channel) {
51 dev_err(tdev->dev, "Channel cannot do Tx\n");
52 return -EINVAL;
53 }
54
55 if (count > MBOX_MAX_SIG_LEN) {
56 dev_err(tdev->dev,
57 "Signal length %zd greater than max allowed %d\n",
58 count, MBOX_MAX_SIG_LEN);
59 return -EINVAL;
60 }
61
62 /* Only allocate memory if we need to */
63 if (!tdev->signal) {
64 tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
65 if (!tdev->signal)
66 return -ENOMEM;
67 }
68
69 if (copy_from_user(tdev->signal, userbuf, count)) {
70 kfree(tdev->signal);
71 tdev->signal = NULL;
72 return -EFAULT;
73 }
74
75 return count;
76}
77
78static const struct file_operations mbox_test_signal_ops = {
79 .write = mbox_test_signal_write,
80 .open = simple_open,
81 .llseek = generic_file_llseek,
82};
83
84static ssize_t mbox_test_message_write(struct file *filp,
85 const char __user *userbuf,
86 size_t count, loff_t *ppos)
87{
88 struct mbox_test_device *tdev = filp->private_data;
89 void *data;
90 int ret;
91
92 if (!tdev->tx_channel) {
93 dev_err(tdev->dev, "Channel cannot do Tx\n");
94 return -EINVAL;
95 }
96
97 if (count > MBOX_MAX_MSG_LEN) {
98 dev_err(tdev->dev,
99 "Message length %zd greater than max allowed %d\n",
100 count, MBOX_MAX_MSG_LEN);
101 return -EINVAL;
102 }
103
104 tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
105 if (!tdev->message)
106 return -ENOMEM;
107
108 ret = copy_from_user(tdev->message, userbuf, count);
109 if (ret) {
110 ret = -EFAULT;
111 goto out;
112 }
113
114 /*
115 * A separate signal is only of use if there is
116 * MMIO to subsequently pass the message through
117 */
118 if (tdev->tx_mmio && tdev->signal) {
119 print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
120 tdev->signal, MBOX_MAX_SIG_LEN);
121
122 data = tdev->signal;
123 } else
124 data = tdev->message;
125
126 print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
127 tdev->message, MBOX_MAX_MSG_LEN);
128
129 ret = mbox_send_message(tdev->tx_channel, data);
130 if (ret < 0)
131 dev_err(tdev->dev, "Failed to send message via mailbox\n");
132
133out:
134 kfree(tdev->signal);
135 kfree(tdev->message);
136
137 return ret < 0 ? ret : count;
138}
139
140static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
141 size_t count, loff_t *ppos)
142{
143 struct mbox_test_device *tdev = filp->private_data;
144 unsigned long flags;
145 char *touser, *ptr;
146 int l = 0;
147 int ret;
148
149 touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
150 if (!touser)
151 return -ENOMEM;
152
153 if (!tdev->rx_channel) {
154 ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
155 ret = simple_read_from_buffer(userbuf, count, ppos,
156 touser, ret);
157 goto out;
158 }
159
160 if (tdev->rx_buffer[0] == '\0') {
161 ret = snprintf(touser, 9, "<EMPTY>\n");
162 ret = simple_read_from_buffer(userbuf, count, ppos,
163 touser, ret);
164 goto out;
165 }
166
167 spin_lock_irqsave(&tdev->lock, flags);
168
169 ptr = tdev->rx_buffer;
170 while (l < MBOX_HEXDUMP_MAX_LEN) {
171 hex_dump_to_buffer(ptr,
172 MBOX_BYTES_PER_LINE,
173 MBOX_BYTES_PER_LINE, 1, touser + l,
174 MBOX_HEXDUMP_LINE_LEN, true);
175
176 ptr += MBOX_BYTES_PER_LINE;
177 l += MBOX_HEXDUMP_LINE_LEN;
178 *(touser + (l - 1)) = '\n';
179 }
180 *(touser + l) = '\0';
181
182 memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
183
184 spin_unlock_irqrestore(&tdev->lock, flags);
185
186 ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
187out:
188 kfree(touser);
189 return ret;
190}
191
192static const struct file_operations mbox_test_message_ops = {
193 .write = mbox_test_message_write,
194 .read = mbox_test_message_read,
195 .open = simple_open,
196 .llseek = generic_file_llseek,
197};
198
199static int mbox_test_add_debugfs(struct platform_device *pdev,
200 struct mbox_test_device *tdev)
201{
202 if (!debugfs_initialized())
203 return 0;
204
205 root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
206 if (!root_debugfs_dir) {
207 dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
208 return -EINVAL;
209 }
210
211 debugfs_create_file("message", 0600, root_debugfs_dir,
212 tdev, &mbox_test_message_ops);
213
214 debugfs_create_file("signal", 0200, root_debugfs_dir,
215 tdev, &mbox_test_signal_ops);
216
217 return 0;
218}
219
220static void mbox_test_receive_message(struct mbox_client *client, void *message)
221{
222 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
223 unsigned long flags;
224
225 spin_lock_irqsave(&tdev->lock, flags);
226 if (tdev->rx_mmio) {
227 memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
228 print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
229 tdev->rx_buffer, MBOX_MAX_MSG_LEN);
230 } else if (message) {
231 print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
232 message, MBOX_MAX_MSG_LEN);
233 memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
234 }
235 spin_unlock_irqrestore(&tdev->lock, flags);
236}
237
238static void mbox_test_prepare_message(struct mbox_client *client, void *message)
239{
240 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
241
242 if (tdev->tx_mmio) {
243 if (tdev->signal)
244 memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
245 else
246 memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
247 }
248}
249
250static void mbox_test_message_sent(struct mbox_client *client,
251 void *message, int r)
252{
253 if (r)
254 dev_warn(client->dev,
255 "Client: Message could not be sent: %d\n", r);
256 else
257 dev_info(client->dev,
258 "Client: Message sent\n");
259}
260
261static struct mbox_chan *
262mbox_test_request_channel(struct platform_device *pdev, const char *name)
263{
264 struct mbox_client *client;
265 struct mbox_chan *channel;
266
267 client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
268 if (!client)
269 return ERR_PTR(-ENOMEM);
270
271 client->dev = &pdev->dev;
272 client->rx_callback = mbox_test_receive_message;
273 client->tx_prepare = mbox_test_prepare_message;
274 client->tx_done = mbox_test_message_sent;
275 client->tx_block = true;
276 client->knows_txdone = false;
277 client->tx_tout = 500;
278
279 channel = mbox_request_channel_byname(client, name);
280 if (IS_ERR(channel)) {
281 dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
282 return NULL;
283 }
284
285 return channel;
286}
287
288static int mbox_test_probe(struct platform_device *pdev)
289{
290 struct mbox_test_device *tdev;
291 struct resource *res;
292 int ret;
293
294 tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
295 if (!tdev)
296 return -ENOMEM;
297
298 /* It's okay for MMIO to be NULL */
299 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
300 tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
301 if (IS_ERR(tdev->tx_mmio))
302 tdev->tx_mmio = NULL;
303
304 /* If specified, second reg entry is Rx MMIO */
305 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
306 tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
307 if (IS_ERR(tdev->rx_mmio))
308 tdev->rx_mmio = tdev->tx_mmio;
309
310 tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
311 tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
312
313 if (!tdev->tx_channel && !tdev->rx_channel)
314 return -EPROBE_DEFER;
315
316 /* If Rx is not specified but has Rx MMIO, then Rx = Tx */
317 if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
318 tdev->rx_channel = tdev->tx_channel;
319
320 tdev->dev = &pdev->dev;
321 platform_set_drvdata(pdev, tdev);
322
323 spin_lock_init(&tdev->lock);
324
325 if (tdev->rx_channel) {
326 tdev->rx_buffer = devm_kzalloc(&pdev->dev,
327 MBOX_MAX_MSG_LEN, GFP_KERNEL);
328 if (!tdev->rx_buffer)
329 return -ENOMEM;
330 }
331
332 ret = mbox_test_add_debugfs(pdev, tdev);
333 if (ret)
334 return ret;
335
336 dev_info(&pdev->dev, "Successfully registered\n");
337
338 return 0;
339}
340
341static int mbox_test_remove(struct platform_device *pdev)
342{
343 struct mbox_test_device *tdev = platform_get_drvdata(pdev);
344
345 debugfs_remove_recursive(root_debugfs_dir);
346
347 if (tdev->tx_channel)
348 mbox_free_channel(tdev->tx_channel);
349 if (tdev->rx_channel)
350 mbox_free_channel(tdev->rx_channel);
351
352 return 0;
353}
354
355static const struct of_device_id mbox_test_match[] = {
356 { .compatible = "mailbox-test" },
357 {},
358};
359
360static struct platform_driver mbox_test_driver = {
361 .driver = {
362 .name = "mailbox_test",
363 .of_match_table = mbox_test_match,
364 },
365 .probe = mbox_test_probe,
366 .remove = mbox_test_remove,
367};
368module_platform_driver(mbox_test_driver);
369
370MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
371MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
372MODULE_LICENSE("GPL v2");