1 // SPDX-License-Identifier: GPL-2.0-only
2 //
3 // Copyright(c) 2023 Google Inc
4 //
5 // Author: Curtis Malainey <cujomalainey@chromium.org>
6 //
7
8 #include <linux/auxiliary_bus.h>
9 #include <linux/debugfs.h>
10 #include <linux/mod_devicetable.h>
11 #include <linux/module.h>
12 #include <linux/pm_runtime.h>
13 #include <sound/sof/header.h>
14
15 #include "sof-client.h"
16
17 #define SOF_IPC_CLIENT_SUSPEND_DELAY_MS 3000
18
19 struct sof_msg_inject_priv {
20 struct dentry *kernel_dfs_file;
21 size_t max_msg_size;
22
23 void *kernel_buffer;
24 };
25
sof_msg_inject_dfs_open(struct inode * inode,struct file * file)26 static int sof_msg_inject_dfs_open(struct inode *inode, struct file *file)
27 {
28 int ret = debugfs_file_get(file->f_path.dentry);
29
30 if (unlikely(ret))
31 return ret;
32
33 ret = simple_open(inode, file);
34 if (ret)
35 debugfs_file_put(file->f_path.dentry);
36
37 return ret;
38 }
39
sof_kernel_msg_inject_dfs_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)40 static ssize_t sof_kernel_msg_inject_dfs_write(struct file *file, const char __user *buffer,
41 size_t count, loff_t *ppos)
42 {
43 struct sof_client_dev *cdev = file->private_data;
44 struct sof_msg_inject_priv *priv = cdev->data;
45 struct sof_ipc_cmd_hdr *hdr = priv->kernel_buffer;
46 struct device *dev = &cdev->auxdev.dev;
47 ssize_t size;
48 int ret;
49
50 if (*ppos)
51 return 0;
52
53 size = simple_write_to_buffer(priv->kernel_buffer, priv->max_msg_size,
54 ppos, buffer, count);
55 if (size < 0)
56 return size;
57 if (size != count)
58 return -EFAULT;
59
60 ret = pm_runtime_resume_and_get(dev);
61 if (ret < 0 && ret != -EACCES) {
62 dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
63 return ret;
64 }
65
66 sof_client_ipc_rx_message(cdev, hdr, priv->kernel_buffer);
67
68 ret = pm_runtime_put_autosuspend(dev);
69 if (ret < 0)
70 dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", ret);
71
72 return count;
73 };
74
sof_msg_inject_dfs_release(struct inode * inode,struct file * file)75 static int sof_msg_inject_dfs_release(struct inode *inode, struct file *file)
76 {
77 debugfs_file_put(file->f_path.dentry);
78
79 return 0;
80 }
81
82 static const struct file_operations sof_kernel_msg_inject_fops = {
83 .open = sof_msg_inject_dfs_open,
84 .write = sof_kernel_msg_inject_dfs_write,
85 .release = sof_msg_inject_dfs_release,
86
87 .owner = THIS_MODULE,
88 };
89
sof_msg_inject_probe(struct auxiliary_device * auxdev,const struct auxiliary_device_id * id)90 static int sof_msg_inject_probe(struct auxiliary_device *auxdev,
91 const struct auxiliary_device_id *id)
92 {
93 struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
94 struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
95 struct device *dev = &auxdev->dev;
96 struct sof_msg_inject_priv *priv;
97 size_t alloc_size;
98
99 /* allocate memory for client data */
100 priv = devm_kzalloc(&auxdev->dev, sizeof(*priv), GFP_KERNEL);
101 if (!priv)
102 return -ENOMEM;
103
104 priv->max_msg_size = sof_client_get_ipc_max_payload_size(cdev);
105 alloc_size = priv->max_msg_size;
106 priv->kernel_buffer = devm_kmalloc(dev, alloc_size, GFP_KERNEL);
107
108 if (!priv->kernel_buffer)
109 return -ENOMEM;
110
111 cdev->data = priv;
112
113 priv->kernel_dfs_file = debugfs_create_file("kernel_ipc_msg_inject", 0644,
114 debugfs_root, cdev,
115 &sof_kernel_msg_inject_fops);
116
117 /* enable runtime PM */
118 pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
119 pm_runtime_use_autosuspend(dev);
120 pm_runtime_set_active(dev);
121 pm_runtime_enable(dev);
122 pm_runtime_mark_last_busy(dev);
123 pm_runtime_idle(dev);
124
125 return 0;
126 }
127
sof_msg_inject_remove(struct auxiliary_device * auxdev)128 static void sof_msg_inject_remove(struct auxiliary_device *auxdev)
129 {
130 struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
131 struct sof_msg_inject_priv *priv = cdev->data;
132
133 pm_runtime_disable(&auxdev->dev);
134
135 debugfs_remove(priv->kernel_dfs_file);
136 }
137
138 static const struct auxiliary_device_id sof_msg_inject_client_id_table[] = {
139 { .name = "snd_sof.kernel_injector" },
140 {},
141 };
142 MODULE_DEVICE_TABLE(auxiliary, sof_msg_inject_client_id_table);
143
144 /*
145 * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
146 * type are enough to ensure that the parent SOF device resumes to bring the DSP
147 * back to D0.
148 * Driver name will be set based on KBUILD_MODNAME.
149 */
150 static struct auxiliary_driver sof_msg_inject_client_drv = {
151 .probe = sof_msg_inject_probe,
152 .remove = sof_msg_inject_remove,
153
154 .id_table = sof_msg_inject_client_id_table,
155 };
156
157 module_auxiliary_driver(sof_msg_inject_client_drv);
158
159 MODULE_LICENSE("GPL");
160 MODULE_DESCRIPTION("SOF IPC Kernel Injector Client Driver");
161 MODULE_IMPORT_NS("SND_SOC_SOF_CLIENT");
162