sound/soc/sof/sof-client-ipc-kernel-injector.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 //
   3 // Copyright(c) 2023 Google Inc. All rights reserved.
   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_DESCRIPTION("SOF IPC Kernel Injector Client Driver");
 161 MODULE_LICENSE("GPL");
 162 MODULE_IMPORT_NS(SND_SOC_SOF_CLIENT);