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 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 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 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 } 127 128 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