light-mailbox-client.c 6.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Copyright (C) 2021 Alibaba Group Holding Limited.
  4. */
  5. #include <linux/debugfs.h>
  6. #include <linux/err.h>
  7. #include <linux/io.h>
  8. #include <linux/kernel.h>
  9. #include <linux/mailbox_client.h>
  10. #include <linux/module.h>
  11. #include <linux/of.h>
  12. #include <linux/of_address.h>
  13. #include <linux/platform_device.h>
  14. #include <linux/slab.h>
  15. #include <linux/uaccess.h>
  16. #define MBOX_MAX_MSG_LEN 28
  17. #define WJ_MBOX_SEND_MAX_MESSAGE_LENGTH 28
  18. #define HEXDUMP_BYTES_PER_LINE 28
  19. #define HEXDUMP_LINE_LEN ((HEXDUMP_BYTES_PER_LINE * 4) + 2)
  20. #define HEXDUMP_MAX_LEN (HEXDUMP_LINE_LEN * \
  21. (MBOX_MAX_MSG_LEN / HEXDUMP_BYTES_PER_LINE))
  22. static struct dentry *root_debugfs_dir;
  23. struct mbox_client_light_device {
  24. struct device *dev;
  25. void __iomem *tx_mmio;
  26. void __iomem *rx_mmio;
  27. struct mbox_chan *tx_channel;
  28. struct mbox_chan *rx_channel;
  29. char *rx_buffer;
  30. char *message;
  31. spinlock_t lock;
  32. };
  33. static ssize_t mbox_client_light_message_write(struct file *filp,
  34. const char __user *userbuf,
  35. size_t count, loff_t *ppos)
  36. {
  37. struct mbox_client_light_device *tdev = filp->private_data;
  38. void *data;
  39. int ret;
  40. if (!tdev->tx_channel) {
  41. dev_err(tdev->dev, "Channel cannot do Tx\n");
  42. return -EINVAL;
  43. }
  44. if (count > WJ_MBOX_SEND_MAX_MESSAGE_LENGTH)
  45. count = WJ_MBOX_SEND_MAX_MESSAGE_LENGTH;
  46. tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
  47. if (!tdev->message)
  48. return -ENOMEM;
  49. ret = copy_from_user(tdev->message, userbuf, count);
  50. if (ret) {
  51. ret = -EFAULT;
  52. goto out;
  53. }
  54. data = tdev->message;
  55. print_hex_dump(KERN_INFO, __func__, DUMP_PREFIX_NONE, 16, 1, tdev->message, MBOX_MAX_MSG_LEN, true);
  56. ret = mbox_send_message(tdev->tx_channel, data);
  57. if (ret < 0)
  58. dev_err(tdev->dev, "Failed to send message via mailbox\n");
  59. out:
  60. kfree(tdev->message);
  61. return ret < 0 ? ret : count;
  62. }
  63. static ssize_t mbox_client_light_message_read(struct file *filp,
  64. char __user *userbuf,
  65. size_t count, loff_t *ppos)
  66. {
  67. struct mbox_client_light_device *tdev = filp->private_data;
  68. unsigned long flags;
  69. print_hex_dump(KERN_INFO, __func__, DUMP_PREFIX_NONE, 16, 1, tdev->rx_buffer, MBOX_MAX_MSG_LEN, true);
  70. spin_lock_irqsave(&tdev->lock, flags);
  71. memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
  72. spin_unlock_irqrestore(&tdev->lock, flags);
  73. return MBOX_MAX_MSG_LEN;
  74. }
  75. static const struct file_operations mbox_client_light_message_ops = {
  76. .write = mbox_client_light_message_write,
  77. .read = mbox_client_light_message_read,
  78. .open = simple_open,
  79. .llseek = generic_file_llseek,
  80. };
  81. static int index_names = 0;
  82. static bool debugfs_dir_created = false;
  83. static const char* file_names[] = {"mbox-client0", "mbox-client1"};
  84. static int mbox_client_light_add_debugfs(struct platform_device *pdev,
  85. struct mbox_client_light_device *tdev)
  86. {
  87. if (!debugfs_initialized())
  88. return 0;
  89. if (index_names > 2) {
  90. dev_err(&pdev->dev, "Max device index is 2\n");
  91. return 0;
  92. }
  93. if (!debugfs_dir_created) {
  94. root_debugfs_dir = debugfs_create_dir("mailbox",NULL);
  95. if (!root_debugfs_dir) {
  96. dev_err(&pdev->dev,
  97. "Failed to create mailbox debugfs\n");
  98. return -EINVAL;
  99. }
  100. debugfs_dir_created = true;
  101. }
  102. debugfs_create_file(file_names[index_names], 0600, root_debugfs_dir,
  103. tdev, &mbox_client_light_message_ops);
  104. index_names++;
  105. return 0;
  106. }
  107. static void mbox_client_light_receive_message(struct mbox_client *client,
  108. void *message)
  109. {
  110. struct mbox_client_light_device *tdev = dev_get_drvdata(client->dev);
  111. char *data = message;
  112. spin_lock(&tdev->lock);
  113. memcpy(tdev->rx_buffer, data, MBOX_MAX_MSG_LEN);
  114. spin_unlock(&tdev->lock);
  115. print_hex_dump(KERN_INFO, __func__, DUMP_PREFIX_NONE, 16, 1, tdev->rx_buffer, MBOX_MAX_MSG_LEN, true);
  116. }
  117. static struct mbox_chan *
  118. mbox_client_light_request_channel(struct platform_device *pdev,
  119. const char *name)
  120. {
  121. struct mbox_client *client;
  122. struct mbox_chan *channel;
  123. client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
  124. if (!client)
  125. return ERR_PTR(-ENOMEM);
  126. client->dev = &pdev->dev;
  127. client->tx_block = true;
  128. client->knows_txdone = false;
  129. client->tx_tout = 500;
  130. client->rx_callback = mbox_client_light_receive_message;
  131. channel = mbox_request_channel_byname(client, name);
  132. if (IS_ERR(channel)) {
  133. devm_kfree(&pdev->dev, client);
  134. dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
  135. return NULL;
  136. }
  137. return channel;
  138. }
  139. static int mbox_client_light_probe(struct platform_device *pdev)
  140. {
  141. struct mbox_client_light_device *tdev;
  142. int ret;
  143. static int chan_idx = 0;
  144. tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
  145. if (!tdev)
  146. return -ENOMEM;
  147. if (!chan_idx)
  148. tdev->tx_channel = mbox_client_light_request_channel(pdev, "902");
  149. else
  150. tdev->tx_channel = mbox_client_light_request_channel(pdev, "906");
  151. if (!tdev->tx_channel) {
  152. dev_err(&pdev->dev, "Request channel failed\n");
  153. return -EPROBE_DEFER;
  154. }
  155. chan_idx++;
  156. /* In fact, rx_channel is same with tx_channel in C-SKY's mailbox */
  157. tdev->rx_channel = tdev->tx_channel;
  158. tdev->dev = &pdev->dev;
  159. platform_set_drvdata(pdev, tdev);
  160. spin_lock_init(&tdev->lock);
  161. tdev->rx_buffer = devm_kzalloc(&pdev->dev,
  162. MBOX_MAX_MSG_LEN, GFP_KERNEL);
  163. if (!tdev->rx_buffer)
  164. return -ENOMEM;
  165. ret = mbox_client_light_add_debugfs(pdev, tdev);
  166. if (ret)
  167. return ret;
  168. dev_info(&pdev->dev, "Successfully registered\n");
  169. return 0;
  170. }
  171. static int mbox_client_light_remove(struct platform_device *pdev)
  172. {
  173. struct mbox_client_light_device *tdev = platform_get_drvdata(pdev);
  174. debugfs_remove_recursive(root_debugfs_dir);
  175. if (tdev->tx_channel)
  176. mbox_free_channel(tdev->tx_channel);
  177. if (tdev->rx_channel && tdev->rx_channel != tdev->tx_channel)
  178. mbox_free_channel(tdev->rx_channel);
  179. return 0;
  180. }
  181. static const struct of_device_id mbox_client_light_match[] = {
  182. { .compatible = "thead,light-mbox-client" },
  183. {},
  184. };
  185. static struct platform_driver mbox_client_light_driver = {
  186. .driver = {
  187. .name = "thead,light-mbox-client",
  188. .of_match_table = mbox_client_light_match,
  189. },
  190. .probe = mbox_client_light_probe,
  191. .remove = mbox_client_light_remove,
  192. };
  193. module_platform_driver(mbox_client_light_driver);
  194. MODULE_AUTHOR("Alibaba Group Holding Limited");
  195. MODULE_DESCRIPTION("Thead Light mailbox IPC client driver");
  196. MODULE_LICENSE("GPL v2");