1 // SPDX-License-Identifier: GPL-2.0-only
2 //
3 // Copyright(c) 2022 Intel Corporation. All rights reserved.
4 //
5 // Author: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
6 //
7 
8 #include <linux/auxiliary_bus.h>
9 #include <linux/completion.h>
10 #include <linux/debugfs.h>
11 #include <linux/ktime.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/slab.h>
16 #include <linux/uaccess.h>
17 #include <sound/sof/header.h>
18 
19 #include "sof-client.h"
20 
21 #define SOF_IPC_CLIENT_SUSPEND_DELAY_MS	3000
22 
23 struct sof_msg_inject_priv {
24 	struct dentry *dfs_file;
25 
26 	void *tx_buffer;
27 	void *rx_buffer;
28 };
29 
30 static int sof_msg_inject_dfs_open(struct inode *inode, struct file *file)
31 {
32 	struct sof_client_dev *cdev = inode->i_private;
33 	int ret;
34 
35 	if (sof_client_get_fw_state(cdev) == SOF_FW_CRASHED)
36 		return -ENODEV;
37 
38 	ret = debugfs_file_get(file->f_path.dentry);
39 	if (unlikely(ret))
40 		return ret;
41 
42 	ret = simple_open(inode, file);
43 	if (ret)
44 		debugfs_file_put(file->f_path.dentry);
45 
46 	return ret;
47 }
48 
49 static ssize_t sof_msg_inject_dfs_read(struct file *file, char __user *buffer,
50 				       size_t count, loff_t *ppos)
51 {
52 	struct sof_client_dev *cdev = file->private_data;
53 	struct sof_msg_inject_priv *priv = cdev->data;
54 	struct sof_ipc_reply *rhdr = priv->rx_buffer;
55 
56 	if (!rhdr->hdr.size || !count || *ppos)
57 		return 0;
58 
59 	if (count > rhdr->hdr.size)
60 		count = rhdr->hdr.size;
61 
62 	if (copy_to_user(buffer, priv->rx_buffer, count))
63 		return -EFAULT;
64 
65 	*ppos += count;
66 	return count;
67 }
68 
69 static ssize_t sof_msg_inject_dfs_write(struct file *file, const char __user *buffer,
70 					size_t count, loff_t *ppos)
71 {
72 	struct sof_client_dev *cdev = file->private_data;
73 	struct sof_msg_inject_priv *priv = cdev->data;
74 	struct device *dev = &cdev->auxdev.dev;
75 	int ret, err;
76 	size_t size;
77 
78 	if (*ppos)
79 		return 0;
80 
81 	size = simple_write_to_buffer(priv->tx_buffer, SOF_IPC_MSG_MAX_SIZE,
82 				      ppos, buffer, count);
83 	if (size != count)
84 		return size > 0 ? -EFAULT : size;
85 
86 	ret = pm_runtime_get_sync(dev);
87 	if (ret < 0 && ret != -EACCES) {
88 		dev_err_ratelimited(dev, "debugfs write failed to resume %d\n", ret);
89 		pm_runtime_put_noidle(dev);
90 		return ret;
91 	}
92 
93 	/* send the message */
94 	memset(priv->rx_buffer, 0, SOF_IPC_MSG_MAX_SIZE);
95 	ret = sof_client_ipc_tx_message(cdev, priv->tx_buffer, priv->rx_buffer,
96 					SOF_IPC_MSG_MAX_SIZE);
97 	pm_runtime_mark_last_busy(dev);
98 	err = pm_runtime_put_autosuspend(dev);
99 	if (err < 0)
100 		dev_err_ratelimited(dev, "debugfs write failed to idle %d\n", err);
101 
102 	/* return size if test is successful */
103 	if (ret >= 0)
104 		ret = size;
105 
106 	return ret;
107 };
108 
109 static int sof_msg_inject_dfs_release(struct inode *inode, struct file *file)
110 {
111 	debugfs_file_put(file->f_path.dentry);
112 
113 	return 0;
114 }
115 
116 static const struct file_operations sof_msg_inject_fops = {
117 	.open = sof_msg_inject_dfs_open,
118 	.read = sof_msg_inject_dfs_read,
119 	.write = sof_msg_inject_dfs_write,
120 	.llseek = default_llseek,
121 	.release = sof_msg_inject_dfs_release,
122 
123 	.owner = THIS_MODULE,
124 };
125 
126 static int sof_msg_inject_probe(struct auxiliary_device *auxdev,
127 				const struct auxiliary_device_id *id)
128 {
129 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
130 	struct dentry *debugfs_root = sof_client_get_debugfs_root(cdev);
131 	struct device *dev = &auxdev->dev;
132 	struct sof_msg_inject_priv *priv;
133 
134 	/* allocate memory for client data */
135 	priv = devm_kzalloc(&auxdev->dev, sizeof(*priv), GFP_KERNEL);
136 	if (!priv)
137 		return -ENOMEM;
138 
139 	priv->tx_buffer = devm_kmalloc(dev, SOF_IPC_MSG_MAX_SIZE, GFP_KERNEL);
140 	priv->rx_buffer = devm_kzalloc(dev, SOF_IPC_MSG_MAX_SIZE, GFP_KERNEL);
141 	if (!priv->tx_buffer || !priv->rx_buffer)
142 		return -ENOMEM;
143 
144 	cdev->data = priv;
145 
146 	priv->dfs_file = debugfs_create_file("ipc_msg_inject", 0644, debugfs_root,
147 					     cdev, &sof_msg_inject_fops);
148 
149 	/* enable runtime PM */
150 	pm_runtime_set_autosuspend_delay(dev, SOF_IPC_CLIENT_SUSPEND_DELAY_MS);
151 	pm_runtime_use_autosuspend(dev);
152 	pm_runtime_enable(dev);
153 	pm_runtime_mark_last_busy(dev);
154 	pm_runtime_idle(dev);
155 
156 	return 0;
157 }
158 
159 static void sof_msg_inject_remove(struct auxiliary_device *auxdev)
160 {
161 	struct sof_client_dev *cdev = auxiliary_dev_to_sof_client_dev(auxdev);
162 	struct sof_msg_inject_priv *priv = cdev->data;
163 
164 	pm_runtime_disable(&auxdev->dev);
165 
166 	debugfs_remove(priv->dfs_file);
167 }
168 
169 static const struct auxiliary_device_id sof_msg_inject_client_id_table[] = {
170 	{ .name = "snd_sof.msg_injector" },
171 	{},
172 };
173 MODULE_DEVICE_TABLE(auxiliary, sof_msg_inject_client_id_table);
174 
175 /*
176  * No need for driver pm_ops as the generic pm callbacks in the auxiliary bus
177  * type are enough to ensure that the parent SOF device resumes to bring the DSP
178  * back to D0.
179  * Driver name will be set based on KBUILD_MODNAME.
180  */
181 static struct auxiliary_driver sof_msg_inject_client_drv = {
182 	.probe = sof_msg_inject_probe,
183 	.remove = sof_msg_inject_remove,
184 
185 	.id_table = sof_msg_inject_client_id_table,
186 };
187 
188 module_auxiliary_driver(sof_msg_inject_client_drv);
189 
190 MODULE_DESCRIPTION("SOF IPC Message Injector Client Driver");
191 MODULE_LICENSE("GPL");
192 MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);
193