| /* Copyright (c) 2017, The Linux Foundation. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 and |
| * only version 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/mailbox_client.h> |
| #include <linux/seq_file.h> |
| #include <linux/debugfs.h> |
| #include <linux/platform_device.h> |
| #include <linux/mailbox/qmp.h> |
| #include <linux/uaccess.h> |
| |
| #define MAX_MSG_SIZE 96 /* Imposed by the remote*/ |
| |
| static struct mbox_chan *chan; |
| static struct mbox_client *cl; |
| |
| static ssize_t aop_msg_write(struct file *file, const char __user *userstr, |
| size_t len, loff_t *pos) |
| { |
| char buf[MAX_MSG_SIZE + 1] = {0}; |
| struct qmp_pkt pkt; |
| int rc; |
| |
| if (!len || (len > MAX_MSG_SIZE)) |
| return len; |
| |
| rc = copy_from_user(buf, userstr, len); |
| if (rc) { |
| pr_err("%s copy from user failed, rc=%d\n", __func__, rc); |
| return len; |
| } |
| |
| /* |
| * Controller expects a 4 byte aligned buffer |
| */ |
| pkt.size = (len + 0x3) & ~0x3; |
| pkt.data = buf; |
| |
| if (mbox_send_message(chan, &pkt) < 0) |
| pr_err("Failed to send qmp request\n"); |
| |
| return len; |
| } |
| |
| static const struct file_operations aop_msg_fops = { |
| .write = aop_msg_write, |
| }; |
| |
| static int qmp_msg_probe(struct platform_device *pdev) |
| { |
| struct dentry *file; |
| |
| cl = devm_kzalloc(&pdev->dev, sizeof(*cl), GFP_KERNEL); |
| if (!cl) |
| return -ENOMEM; |
| |
| cl->dev = &pdev->dev; |
| cl->tx_block = true; |
| cl->tx_tout = 100; |
| cl->knows_txdone = false; |
| |
| chan = mbox_request_channel(cl, 0); |
| if (IS_ERR(chan)) { |
| dev_err(&pdev->dev, "Failed to mbox channel\n"); |
| return PTR_ERR(chan); |
| } |
| |
| file = debugfs_create_file("aop_send_message", 0220, NULL, NULL, |
| &aop_msg_fops); |
| if (!file) |
| goto err; |
| return 0; |
| err: |
| mbox_free_channel(chan); |
| chan = NULL; |
| return -ENOMEM; |
| } |
| |
| static const struct of_device_id aop_qmp_match_tbl[] = { |
| {.compatible = "qcom,debugfs-qmp-client"}, |
| {}, |
| }; |
| |
| static struct platform_driver aop_qmp_msg_driver = { |
| .probe = qmp_msg_probe, |
| .driver = { |
| .name = "debugfs-qmp-client", |
| .owner = THIS_MODULE, |
| .of_match_table = aop_qmp_match_tbl, |
| }, |
| }; |
| |
| builtin_platform_driver(aop_qmp_msg_driver); |