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