xref: /openbmc/linux/sound/hda/hdac_bus.c (revision 6d99a79c)
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 void process_unsol_events(struct work_struct *work);
13 
14 static const struct hdac_bus_ops default_ops = {
15 	.command = snd_hdac_bus_send_cmd,
16 	.get_response = snd_hdac_bus_get_response,
17 };
18 
19 /**
20  * snd_hdac_bus_init - initialize a HD-audio bas bus
21  * @bus: the pointer to bus object
22  * @ops: bus verb operators
23  * @io_ops: lowlevel I/O operators
24  *
25  * Returns 0 if successful, or a negative error code.
26  */
27 int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
28 		      const struct hdac_bus_ops *ops,
29 		      const struct hdac_io_ops *io_ops)
30 {
31 	memset(bus, 0, sizeof(*bus));
32 	bus->dev = dev;
33 	if (ops)
34 		bus->ops = ops;
35 	else
36 		bus->ops = &default_ops;
37 	bus->io_ops = io_ops;
38 	INIT_LIST_HEAD(&bus->stream_list);
39 	INIT_LIST_HEAD(&bus->codec_list);
40 	INIT_WORK(&bus->unsol_work, process_unsol_events);
41 	spin_lock_init(&bus->reg_lock);
42 	mutex_init(&bus->cmd_mutex);
43 	bus->irq = -1;
44 	return 0;
45 }
46 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
47 
48 /**
49  * snd_hdac_bus_exit - clean up a HD-audio bas bus
50  * @bus: the pointer to bus object
51  */
52 void snd_hdac_bus_exit(struct hdac_bus *bus)
53 {
54 	WARN_ON(!list_empty(&bus->stream_list));
55 	WARN_ON(!list_empty(&bus->codec_list));
56 	cancel_work_sync(&bus->unsol_work);
57 }
58 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
59 
60 /**
61  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
62  * @bus: bus object
63  * @cmd: HD-audio encoded verb
64  * @res: pointer to store the response, NULL if performing asynchronously
65  *
66  * Returns 0 if successful, or a negative error code.
67  */
68 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
69 			   unsigned int cmd, unsigned int *res)
70 {
71 	int err;
72 
73 	mutex_lock(&bus->cmd_mutex);
74 	err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
75 	mutex_unlock(&bus->cmd_mutex);
76 	return err;
77 }
78 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb);
79 
80 /**
81  * snd_hdac_bus_exec_verb_unlocked - unlocked version
82  * @bus: bus object
83  * @cmd: HD-audio encoded verb
84  * @res: pointer to store the response, NULL if performing asynchronously
85  *
86  * Returns 0 if successful, or a negative error code.
87  */
88 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
89 				    unsigned int cmd, unsigned int *res)
90 {
91 	unsigned int tmp;
92 	int err;
93 
94 	if (cmd == ~0)
95 		return -EINVAL;
96 
97 	if (res)
98 		*res = -1;
99 	else if (bus->sync_write)
100 		res = &tmp;
101 	for (;;) {
102 		trace_hda_send_cmd(bus, cmd);
103 		err = bus->ops->command(bus, cmd);
104 		if (err != -EAGAIN)
105 			break;
106 		/* process pending verbs */
107 		err = bus->ops->get_response(bus, addr, &tmp);
108 		if (err)
109 			break;
110 	}
111 	if (!err && res) {
112 		err = bus->ops->get_response(bus, addr, res);
113 		trace_hda_get_response(bus, addr, *res);
114 	}
115 	return err;
116 }
117 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
118 
119 /**
120  * snd_hdac_bus_queue_event - add an unsolicited event to queue
121  * @bus: the BUS
122  * @res: unsolicited event (lower 32bit of RIRB entry)
123  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
124  *
125  * Adds the given event to the queue.  The events are processed in
126  * the workqueue asynchronously.  Call this function in the interrupt
127  * hanlder when RIRB receives an unsolicited event.
128  */
129 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
130 {
131 	unsigned int wp;
132 
133 	if (!bus)
134 		return;
135 
136 	trace_hda_unsol_event(bus, res, res_ex);
137 	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
138 	bus->unsol_wp = wp;
139 
140 	wp <<= 1;
141 	bus->unsol_queue[wp] = res;
142 	bus->unsol_queue[wp + 1] = res_ex;
143 
144 	schedule_work(&bus->unsol_work);
145 }
146 EXPORT_SYMBOL_GPL(snd_hdac_bus_queue_event);
147 
148 /*
149  * process queued unsolicited events
150  */
151 static void process_unsol_events(struct work_struct *work)
152 {
153 	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
154 	struct hdac_device *codec;
155 	struct hdac_driver *drv;
156 	unsigned int rp, caddr, res;
157 
158 	while (bus->unsol_rp != bus->unsol_wp) {
159 		rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
160 		bus->unsol_rp = rp;
161 		rp <<= 1;
162 		res = bus->unsol_queue[rp];
163 		caddr = bus->unsol_queue[rp + 1];
164 		if (!(caddr & (1 << 4))) /* no unsolicited event? */
165 			continue;
166 		codec = bus->caddr_tbl[caddr & 0x0f];
167 		if (!codec || !codec->dev.driver)
168 			continue;
169 		drv = drv_to_hdac_driver(codec->dev.driver);
170 		if (drv->unsol_event)
171 			drv->unsol_event(codec, res);
172 	}
173 }
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