xref: /linux/sound/hda/hdac_bus.c (revision ec63e2a4897075e427c121d863bd89c44578094f)
1 /*
2  * HD-audio core bus driver
3  */
4 
5 #include <linux/init.h>
6 #include <linux/device.h>
7 #include <linux/module.h>
8 #include <linux/export.h>
9 #include <sound/hdaudio.h>
10 #include "trace.h"
11 
12 static const struct hdac_bus_ops default_ops = {
13 	.command = snd_hdac_bus_send_cmd,
14 	.get_response = snd_hdac_bus_get_response,
15 };
16 
17 /**
18  * snd_hdac_bus_init - initialize a HD-audio bas bus
19  * @bus: the pointer to bus object
20  * @ops: bus verb operators
21  * @io_ops: lowlevel I/O operators
22  *
23  * Returns 0 if successful, or a negative error code.
24  */
25 int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
26 		      const struct hdac_bus_ops *ops,
27 		      const struct hdac_io_ops *io_ops)
28 {
29 	memset(bus, 0, sizeof(*bus));
30 	bus->dev = dev;
31 	if (ops)
32 		bus->ops = ops;
33 	else
34 		bus->ops = &default_ops;
35 	bus->io_ops = io_ops;
36 	INIT_LIST_HEAD(&bus->stream_list);
37 	INIT_LIST_HEAD(&bus->codec_list);
38 	INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events);
39 	spin_lock_init(&bus->reg_lock);
40 	mutex_init(&bus->cmd_mutex);
41 	mutex_init(&bus->lock);
42 	bus->irq = -1;
43 	return 0;
44 }
45 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
46 
47 /**
48  * snd_hdac_bus_exit - clean up a HD-audio bas bus
49  * @bus: the pointer to bus object
50  */
51 void snd_hdac_bus_exit(struct hdac_bus *bus)
52 {
53 	WARN_ON(!list_empty(&bus->stream_list));
54 	WARN_ON(!list_empty(&bus->codec_list));
55 	cancel_work_sync(&bus->unsol_work);
56 }
57 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
58 
59 /**
60  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
61  * @bus: bus object
62  * @cmd: HD-audio encoded verb
63  * @res: pointer to store the response, NULL if performing asynchronously
64  *
65  * Returns 0 if successful, or a negative error code.
66  */
67 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
68 			   unsigned int cmd, unsigned int *res)
69 {
70 	int err;
71 
72 	mutex_lock(&bus->cmd_mutex);
73 	err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
74 	mutex_unlock(&bus->cmd_mutex);
75 	return err;
76 }
77 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb);
78 
79 /**
80  * snd_hdac_bus_exec_verb_unlocked - unlocked version
81  * @bus: bus object
82  * @cmd: HD-audio encoded verb
83  * @res: pointer to store the response, NULL if performing asynchronously
84  *
85  * Returns 0 if successful, or a negative error code.
86  */
87 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
88 				    unsigned int cmd, unsigned int *res)
89 {
90 	unsigned int tmp;
91 	int err;
92 
93 	if (cmd == ~0)
94 		return -EINVAL;
95 
96 	if (res)
97 		*res = -1;
98 	else if (bus->sync_write)
99 		res = &tmp;
100 	for (;;) {
101 		trace_hda_send_cmd(bus, cmd);
102 		err = bus->ops->command(bus, cmd);
103 		if (err != -EAGAIN)
104 			break;
105 		/* process pending verbs */
106 		err = bus->ops->get_response(bus, addr, &tmp);
107 		if (err)
108 			break;
109 	}
110 	if (!err && res) {
111 		err = bus->ops->get_response(bus, addr, res);
112 		trace_hda_get_response(bus, addr, *res);
113 	}
114 	return err;
115 }
116 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
117 
118 /**
119  * snd_hdac_bus_queue_event - add an unsolicited event to queue
120  * @bus: the BUS
121  * @res: unsolicited event (lower 32bit of RIRB entry)
122  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
123  *
124  * Adds the given event to the queue.  The events are processed in
125  * the workqueue asynchronously.  Call this function in the interrupt
126  * hanlder when RIRB receives an unsolicited event.
127  */
128 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
129 {
130 	unsigned int wp;
131 
132 	if (!bus)
133 		return;
134 
135 	trace_hda_unsol_event(bus, res, res_ex);
136 	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
137 	bus->unsol_wp = wp;
138 
139 	wp <<= 1;
140 	bus->unsol_queue[wp] = res;
141 	bus->unsol_queue[wp + 1] = res_ex;
142 
143 	schedule_work(&bus->unsol_work);
144 }
145 EXPORT_SYMBOL_GPL(snd_hdac_bus_queue_event);
146 
147 /*
148  * process queued unsolicited events
149  */
150 void snd_hdac_bus_process_unsol_events(struct work_struct *work)
151 {
152 	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
153 	struct hdac_device *codec;
154 	struct hdac_driver *drv;
155 	unsigned int rp, caddr, res;
156 
157 	while (bus->unsol_rp != bus->unsol_wp) {
158 		rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
159 		bus->unsol_rp = rp;
160 		rp <<= 1;
161 		res = bus->unsol_queue[rp];
162 		caddr = bus->unsol_queue[rp + 1];
163 		if (!(caddr & (1 << 4))) /* no unsolicited event? */
164 			continue;
165 		codec = bus->caddr_tbl[caddr & 0x0f];
166 		if (!codec || !codec->dev.driver)
167 			continue;
168 		drv = drv_to_hdac_driver(codec->dev.driver);
169 		if (drv->unsol_event)
170 			drv->unsol_event(codec, res);
171 	}
172 }
173 EXPORT_SYMBOL_GPL(snd_hdac_bus_process_unsol_events);
174 
175 /**
176  * snd_hdac_bus_add_device - Add a codec to bus
177  * @bus: HDA core bus
178  * @codec: HDA core device to add
179  *
180  * Adds the given codec to the list in the bus.  The caddr_tbl array
181  * and codec_powered bits are updated, as well.
182  * Returns zero if success, or a negative error code.
183  */
184 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
185 {
186 	if (bus->caddr_tbl[codec->addr]) {
187 		dev_err(bus->dev, "address 0x%x is already occupied\n",
188 			codec->addr);
189 		return -EBUSY;
190 	}
191 
192 	list_add_tail(&codec->list, &bus->codec_list);
193 	bus->caddr_tbl[codec->addr] = codec;
194 	set_bit(codec->addr, &bus->codec_powered);
195 	bus->num_codecs++;
196 	return 0;
197 }
198 EXPORT_SYMBOL_GPL(snd_hdac_bus_add_device);
199 
200 /**
201  * snd_hdac_bus_remove_device - Remove a codec from bus
202  * @bus: HDA core bus
203  * @codec: HDA core device to remove
204  */
205 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
206 				struct hdac_device *codec)
207 {
208 	WARN_ON(bus != codec->bus);
209 	if (list_empty(&codec->list))
210 		return;
211 	list_del_init(&codec->list);
212 	bus->caddr_tbl[codec->addr] = NULL;
213 	clear_bit(codec->addr, &bus->codec_powered);
214 	bus->num_codecs--;
215 	flush_work(&bus->unsol_work);
216 }
217 EXPORT_SYMBOL_GPL(snd_hdac_bus_remove_device);
218