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
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
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 pm_runtime_mark_last_busy(dev);
69 ret = pm_runtime_put_autosuspend(dev);
70 if (ret < 0)
71 dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", ret);
72
73 return count;
74 };
75
76 static int sof_msg_inject_dfs_release(struct inode *inode, struct file *file)
77 {
78 debugfs_file_put(file->f_path.dentry);
79
80 return 0;
81 }
82
83 static const struct file_operations sof_kernel_msg_inject_fops = {
84 .open = sof_msg_inject_dfs_open,
85 .write = sof_kernel_msg_inject_dfs_write,
86 .release = sof_msg_inject_dfs_release,
87
88 .owner = THIS_MODULE,
89 };
90
91 static int sof_msg_inject_probe(struct auxiliary_device *auxdev,
92 const struct auxiliary_device_id *id)
93 {
94 struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
95 struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
96 struct device *dev = &auxdev->dev;
97 struct sof_msg_inject_priv *priv;
98 size_t alloc_size;
99
100 /* allocate memory for client data */
101 priv = devm_kzalloc(&auxdev->dev, sizeof(*priv), GFP_KERNEL);
102 if (!priv)
103 return -ENOMEM;
104
105 priv->max_msg_size = sof_client_get_ipc_max_payload_size(cdev);
106 alloc_size = priv->max_msg_size;
107 priv->kernel_buffer = devm_kmalloc(dev, alloc_size, GFP_KERNEL);
108
109 if (!priv->kernel_buffer)
110 return -ENOMEM;
111
112 cdev->data = priv;
113
114 priv->kernel_dfs_file = debugfs_create_file("kernel_ipc_msg_inject", 0644,
115 debugfs_root, cdev,
116 &sof_kernel_msg_inject_fops);
117
118 /* enable runtime PM */
119 pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
120 pm_runtime_use_autosuspend(dev);
121 pm_runtime_set_active(dev);
122 pm_runtime_enable(dev);
123 pm_runtime_mark_last_busy(dev);
124 pm_runtime_idle(dev);
125
126 return 0;
127 }
128
129 static void sof_msg_inject_remove(struct auxiliary_device *auxdev)
130 {
131 struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
132 struct sof_msg_inject_priv *priv = cdev->data;
133
134 pm_runtime_disable(&auxdev->dev);
135
136 debugfs_remove(priv->kernel_dfs_file);
137 }
138
139 static const struct auxiliary_device_id sof_msg_inject_client_id_table[] = {
140 { .name = "snd_sof.kernel_injector" },
141 {},
142 };
143 MODULE_DEVICE_TABLE(auxiliary, sof_msg_inject_client_id_table);
144
145 /*
146 * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
147 * type are enough to ensure that the parent SOF device resumes to bring the DSP
148 * back to D0.
149 * Driver name will be set based on KBUILD_MODNAME.
150 */
151 static struct auxiliary_driver sof_msg_inject_client_drv = {
152 .probe = sof_msg_inject_probe,
153 .remove = sof_msg_inject_remove,
154
155 .id_table = sof_msg_inject_client_id_table,
156 };
157
158 module_auxiliary_driver(sof_msg_inject_client_drv);
159
160 MODULE_LICENSE("GPL");
161 MODULE_DESCRIPTION("SOF IPC Kernel Injector Client Driver");
162 MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);
163
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