linux/sound/hda/hdac_bus.c
Takashi Iwai 78dd5e21b0 ALSA: hda - Add / fix kernel doc comments
Give some readable comment in kernel doc style for each exported
function, as I promised in the previous meetings.  While we're at it,
fix the wrong comments, too.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-10-28 12:37:29 +01:00

217 lines
5.4 KiB
C

/*
* HD-audio core bus driver
*/
#include <linux/init.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/export.h>
#include <sound/hdaudio.h>
#include "trace.h"
static void process_unsol_events(struct work_struct *work);
static const struct hdac_bus_ops default_ops = {
.command = snd_hdac_bus_send_cmd,
.get_response = snd_hdac_bus_get_response,
};
/**
* snd_hdac_bus_init - initialize a HD-audio bas bus
* @bus: the pointer to bus object
* @ops: bus verb operators
* @io_ops: lowlevel I/O operators
*
* Returns 0 if successful, or a negative error code.
*/
int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
const struct hdac_bus_ops *ops,
const struct hdac_io_ops *io_ops)
{
memset(bus, 0, sizeof(*bus));
bus->dev = dev;
if (ops)
bus->ops = ops;
else
bus->ops = &default_ops;
bus->io_ops = io_ops;
INIT_LIST_HEAD(&bus->stream_list);
INIT_LIST_HEAD(&bus->codec_list);
INIT_WORK(&bus->unsol_work, process_unsol_events);
spin_lock_init(&bus->reg_lock);
mutex_init(&bus->cmd_mutex);
bus->irq = -1;
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
/**
* snd_hdac_bus_exit - clean up a HD-audio bas bus
* @bus: the pointer to bus object
*/
void snd_hdac_bus_exit(struct hdac_bus *bus)
{
WARN_ON(!list_empty(&bus->stream_list));
WARN_ON(!list_empty(&bus->codec_list));
cancel_work_sync(&bus->unsol_work);
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
/**
* snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
* @bus: bus object
* @cmd: HD-audio encoded verb
* @res: pointer to store the response, NULL if performing asynchronously
*
* Returns 0 if successful, or a negative error code.
*/
int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
unsigned int cmd, unsigned int *res)
{
int err;
mutex_lock(&bus->cmd_mutex);
err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
mutex_unlock(&bus->cmd_mutex);
return err;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb);
/**
* snd_hdac_bus_exec_verb_unlocked - unlocked version
* @bus: bus object
* @cmd: HD-audio encoded verb
* @res: pointer to store the response, NULL if performing asynchronously
*
* Returns 0 if successful, or a negative error code.
*/
int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
unsigned int cmd, unsigned int *res)
{
unsigned int tmp;
int err;
if (cmd == ~0)
return -EINVAL;
if (res)
*res = -1;
else if (bus->sync_write)
res = &tmp;
for (;;) {
trace_hda_send_cmd(bus, cmd);
err = bus->ops->command(bus, cmd);
if (err != -EAGAIN)
break;
/* process pending verbs */
err = bus->ops->get_response(bus, addr, &tmp);
if (err)
break;
}
if (!err && res) {
err = bus->ops->get_response(bus, addr, res);
trace_hda_get_response(bus, addr, *res);
}
return err;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
/**
* snd_hdac_bus_queue_event - add an unsolicited event to queue
* @bus: the BUS
* @res: unsolicited event (lower 32bit of RIRB entry)
* @res_ex: codec addr and flags (upper 32bit or RIRB entry)
*
* Adds the given event to the queue. The events are processed in
* the workqueue asynchronously. Call this function in the interrupt
* hanlder when RIRB receives an unsolicited event.
*/
void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
{
unsigned int wp;
if (!bus)
return;
trace_hda_unsol_event(bus, res, res_ex);
wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
bus->unsol_wp = wp;
wp <<= 1;
bus->unsol_queue[wp] = res;
bus->unsol_queue[wp + 1] = res_ex;
schedule_work(&bus->unsol_work);
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_queue_event);
/*
* process queued unsolicited events
*/
static void process_unsol_events(struct work_struct *work)
{
struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
struct hdac_device *codec;
struct hdac_driver *drv;
unsigned int rp, caddr, res;
while (bus->unsol_rp != bus->unsol_wp) {
rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
bus->unsol_rp = rp;
rp <<= 1;
res = bus->unsol_queue[rp];
caddr = bus->unsol_queue[rp + 1];
if (!(caddr & (1 << 4))) /* no unsolicited event? */
continue;
codec = bus->caddr_tbl[caddr & 0x0f];
if (!codec || !codec->dev.driver)
continue;
drv = drv_to_hdac_driver(codec->dev.driver);
if (drv->unsol_event)
drv->unsol_event(codec, res);
}
}
/**
* snd_hdac_bus_add_device - Add a codec to bus
* @bus: HDA core bus
* @codec: HDA core device to add
*
* Adds the given codec to the list in the bus. The caddr_tbl array
* and codec_powered bits are updated, as well.
* Returns zero if success, or a negative error code.
*/
int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
{
if (bus->caddr_tbl[codec->addr]) {
dev_err(bus->dev, "address 0x%x is already occupied\n",
codec->addr);
return -EBUSY;
}
list_add_tail(&codec->list, &bus->codec_list);
bus->caddr_tbl[codec->addr] = codec;
set_bit(codec->addr, &bus->codec_powered);
bus->num_codecs++;
return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_add_device);
/**
* snd_hdac_bus_remove_device - Remove a codec from bus
* @bus: HDA core bus
* @codec: HDA core device to remove
*/
void snd_hdac_bus_remove_device(struct hdac_bus *bus,
struct hdac_device *codec)
{
WARN_ON(bus != codec->bus);
if (list_empty(&codec->list))
return;
list_del_init(&codec->list);
bus->caddr_tbl[codec->addr] = NULL;
clear_bit(codec->addr, &bus->codec_powered);
bus->num_codecs--;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_remove_device);