1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * HD-audio bus 4 */ 5 #include <linux/init.h> 6 #include <linux/device.h> 7 #include <linux/module.h> 8 #include <linux/mod_devicetable.h> 9 #include <linux/export.h> 10 #include <sound/hdaudio.h> 11 12 MODULE_DESCRIPTION("HD-audio bus"); 13 MODULE_LICENSE("GPL"); 14 15 /** 16 * hdac_get_device_id - gets the hdac device id entry 17 * @hdev: HD-audio core device 18 * @drv: HD-audio codec driver 19 * 20 * Compares the hdac device vendor_id and revision_id to the hdac_device 21 * driver id_table and returns the matching device id entry. 22 */ 23 const struct hda_device_id * 24 hdac_get_device_id(struct hdac_device *hdev, struct hdac_driver *drv) 25 { 26 if (drv->id_table) { 27 const struct hda_device_id *id = drv->id_table; 28 29 while (id->vendor_id) { 30 if (hdev->vendor_id == id->vendor_id && 31 (!id->rev_id || id->rev_id == hdev->revision_id)) 32 return id; 33 id++; 34 } 35 } 36 37 return NULL; 38 } 39 EXPORT_SYMBOL_GPL(hdac_get_device_id); 40 41 static int hdac_codec_match(struct hdac_device *dev, struct hdac_driver *drv) 42 { 43 if (hdac_get_device_id(dev, drv)) 44 return 1; 45 else 46 return 0; 47 } 48 49 static int hda_bus_match(struct device *dev, struct device_driver *drv) 50 { 51 struct hdac_device *hdev = dev_to_hdac_dev(dev); 52 struct hdac_driver *hdrv = drv_to_hdac_driver(drv); 53 54 if (hdev->type != hdrv->type) 55 return 0; 56 57 /* 58 * if driver provided a match function use that otherwise we will 59 * use hdac_codec_match function 60 */ 61 if (hdrv->match) 62 return hdrv->match(hdev, hdrv); 63 else 64 return hdac_codec_match(hdev, hdrv); 65 return 1; 66 } 67 68 static int hda_uevent(struct device *dev, struct kobj_uevent_env *env) 69 { 70 char modalias[32]; 71 72 snd_hdac_codec_modalias(dev_to_hdac_dev(dev), modalias, 73 sizeof(modalias)); 74 if (add_uevent_var(env, "MODALIAS=%s", modalias)) 75 return -ENOMEM; 76 return 0; 77 } 78 79 struct bus_type snd_hda_bus_type = { 80 .name = "hdaudio", 81 .match = hda_bus_match, 82 .uevent = hda_uevent, 83 }; 84 EXPORT_SYMBOL_GPL(snd_hda_bus_type); 85 86 static int __init hda_bus_init(void) 87 { 88 return bus_register(&snd_hda_bus_type); 89 } 90 91 static void __exit hda_bus_exit(void) 92 { 93 bus_unregister(&snd_hda_bus_type); 94 } 95 96 subsys_initcall(hda_bus_init); 97 module_exit(hda_bus_exit); 98