xref: /openbmc/linux/sound/pci/hda/hda_hwdep.c (revision be709d48)
1 /*
2  * HWDEP Interface for HD-audio codec
3  *
4  * Copyright (c) 2007 Takashi Iwai <tiwai@suse.de>
5  *
6  *  This driver is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This driver is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  */
20 
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <linux/compat.h>
24 #include <linux/nospec.h>
25 #include <sound/core.h>
26 #include <sound/hda_codec.h>
27 #include "hda_local.h"
28 #include <sound/hda_hwdep.h>
29 #include <sound/minors.h>
30 
31 /*
32  * write/read an out-of-bound verb
33  */
34 static int verb_write_ioctl(struct hda_codec *codec,
35 			    struct hda_verb_ioctl __user *arg)
36 {
37 	u32 verb, res;
38 
39 	if (get_user(verb, &arg->verb))
40 		return -EFAULT;
41 	res = snd_hda_codec_read(codec, verb >> 24, 0,
42 				 (verb >> 8) & 0xffff, verb & 0xff);
43 	if (put_user(res, &arg->res))
44 		return -EFAULT;
45 	return 0;
46 }
47 
48 static int get_wcap_ioctl(struct hda_codec *codec,
49 			  struct hda_verb_ioctl __user *arg)
50 {
51 	u32 verb, res;
52 
53 	if (get_user(verb, &arg->verb))
54 		return -EFAULT;
55 	/* open-code get_wcaps(verb>>24) with nospec */
56 	verb >>= 24;
57 	if (verb < codec->core.start_nid ||
58 	    verb >= codec->core.start_nid + codec->core.num_nodes) {
59 		res = 0;
60 	} else {
61 		verb -= codec->core.start_nid;
62 		verb = array_index_nospec(verb, codec->core.num_nodes);
63 		res = codec->wcaps[verb];
64 	}
65 	if (put_user(res, &arg->res))
66 		return -EFAULT;
67 	return 0;
68 }
69 
70 
71 /*
72  */
73 static int hda_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
74 			   unsigned int cmd, unsigned long arg)
75 {
76 	struct hda_codec *codec = hw->private_data;
77 	void __user *argp = (void __user *)arg;
78 
79 	switch (cmd) {
80 	case HDA_IOCTL_PVERSION:
81 		return put_user(HDA_HWDEP_VERSION, (int __user *)argp);
82 	case HDA_IOCTL_VERB_WRITE:
83 		return verb_write_ioctl(codec, argp);
84 	case HDA_IOCTL_GET_WCAP:
85 		return get_wcap_ioctl(codec, argp);
86 	}
87 	return -ENOIOCTLCMD;
88 }
89 
90 #ifdef CONFIG_COMPAT
91 static int hda_hwdep_ioctl_compat(struct snd_hwdep *hw, struct file *file,
92 				  unsigned int cmd, unsigned long arg)
93 {
94 	return hda_hwdep_ioctl(hw, file, cmd, (unsigned long)compat_ptr(arg));
95 }
96 #endif
97 
98 static int hda_hwdep_open(struct snd_hwdep *hw, struct file *file)
99 {
100 #ifndef CONFIG_SND_DEBUG_VERBOSE
101 	if (!capable(CAP_SYS_RAWIO))
102 		return -EACCES;
103 #endif
104 	return 0;
105 }
106 
107 int snd_hda_create_hwdep(struct hda_codec *codec)
108 {
109 	char hwname[16];
110 	struct snd_hwdep *hwdep;
111 	int err;
112 
113 	sprintf(hwname, "HDA Codec %d", codec->addr);
114 	err = snd_hwdep_new(codec->card, hwname, codec->addr, &hwdep);
115 	if (err < 0)
116 		return err;
117 	codec->hwdep = hwdep;
118 	sprintf(hwdep->name, "HDA Codec %d", codec->addr);
119 	hwdep->iface = SNDRV_HWDEP_IFACE_HDA;
120 	hwdep->private_data = codec;
121 	hwdep->exclusive = 1;
122 
123 	hwdep->ops.open = hda_hwdep_open;
124 	hwdep->ops.ioctl = hda_hwdep_ioctl;
125 #ifdef CONFIG_COMPAT
126 	hwdep->ops.ioctl_compat = hda_hwdep_ioctl_compat;
127 #endif
128 
129 	/* for sysfs */
130 	hwdep->dev.groups = snd_hda_dev_attr_groups;
131 	dev_set_drvdata(&hwdep->dev, codec);
132 
133 	return 0;
134 }
135