xref: /openbmc/linux/sound/pci/hda/hda_hwdep.c (revision 9470114d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * HWDEP Interface for HD-audio codec
4  *
5  * Copyright (c) 2007 Takashi Iwai <tiwai@suse.de>
6  */
7 
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/compat.h>
11 #include <linux/nospec.h>
12 #include <sound/core.h>
13 #include <sound/hda_codec.h>
14 #include "hda_local.h"
15 #include <sound/hda_hwdep.h>
16 #include <sound/minors.h>
17 
18 /*
19  * write/read an out-of-bound verb
20  */
21 static int verb_write_ioctl(struct hda_codec *codec,
22 			    struct hda_verb_ioctl __user *arg)
23 {
24 	u32 verb, res;
25 
26 	if (get_user(verb, &arg->verb))
27 		return -EFAULT;
28 	res = snd_hda_codec_read(codec, verb >> 24, 0,
29 				 (verb >> 8) & 0xffff, verb & 0xff);
30 	if (put_user(res, &arg->res))
31 		return -EFAULT;
32 	return 0;
33 }
34 
35 static int get_wcap_ioctl(struct hda_codec *codec,
36 			  struct hda_verb_ioctl __user *arg)
37 {
38 	u32 verb, res;
39 
40 	if (get_user(verb, &arg->verb))
41 		return -EFAULT;
42 	/* open-code get_wcaps(verb>>24) with nospec */
43 	verb >>= 24;
44 	if (verb < codec->core.start_nid ||
45 	    verb >= codec->core.start_nid + codec->core.num_nodes) {
46 		res = 0;
47 	} else {
48 		verb -= codec->core.start_nid;
49 		verb = array_index_nospec(verb, codec->core.num_nodes);
50 		res = codec->wcaps[verb];
51 	}
52 	if (put_user(res, &arg->res))
53 		return -EFAULT;
54 	return 0;
55 }
56 
57 
58 /*
59  */
60 static int hda_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
61 			   unsigned int cmd, unsigned long arg)
62 {
63 	struct hda_codec *codec = hw->private_data;
64 	void __user *argp = (void __user *)arg;
65 
66 	switch (cmd) {
67 	case HDA_IOCTL_PVERSION:
68 		return put_user(HDA_HWDEP_VERSION, (int __user *)argp);
69 	case HDA_IOCTL_VERB_WRITE:
70 		return verb_write_ioctl(codec, argp);
71 	case HDA_IOCTL_GET_WCAP:
72 		return get_wcap_ioctl(codec, argp);
73 	}
74 	return -ENOIOCTLCMD;
75 }
76 
77 #ifdef CONFIG_COMPAT
78 static int hda_hwdep_ioctl_compat(struct snd_hwdep *hw, struct file *file,
79 				  unsigned int cmd, unsigned long arg)
80 {
81 	return hda_hwdep_ioctl(hw, file, cmd, (unsigned long)compat_ptr(arg));
82 }
83 #endif
84 
85 static int hda_hwdep_open(struct snd_hwdep *hw, struct file *file)
86 {
87 #ifndef CONFIG_SND_DEBUG_VERBOSE
88 	if (!capable(CAP_SYS_RAWIO))
89 		return -EACCES;
90 #endif
91 	return 0;
92 }
93 
94 int snd_hda_create_hwdep(struct hda_codec *codec)
95 {
96 	char hwname[16];
97 	struct snd_hwdep *hwdep;
98 	int err;
99 
100 	sprintf(hwname, "HDA Codec %d", codec->addr);
101 	err = snd_hwdep_new(codec->card, hwname, codec->addr, &hwdep);
102 	if (err < 0)
103 		return err;
104 	codec->hwdep = hwdep;
105 	sprintf(hwdep->name, "HDA Codec %d", codec->addr);
106 	hwdep->iface = SNDRV_HWDEP_IFACE_HDA;
107 	hwdep->private_data = codec;
108 	hwdep->exclusive = 1;
109 
110 	hwdep->ops.open = hda_hwdep_open;
111 	hwdep->ops.ioctl = hda_hwdep_ioctl;
112 #ifdef CONFIG_COMPAT
113 	hwdep->ops.ioctl_compat = hda_hwdep_ioctl_compat;
114 #endif
115 
116 	/* for sysfs */
117 	hwdep->dev->groups = snd_hda_dev_attr_groups;
118 	dev_set_drvdata(hwdep->dev, codec);
119 
120 	return 0;
121 }
122