drivers/mailbox/mailbox-test.c

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