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