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linux/sound/core/jack.c
Takashi Iwai 495000a386 ALSA: core: Remove debugfs at disconnection
The card-specific debugfs entries are removed at the last stage of
card free phase, and it's performed after synchronization of the
closes of all opened fds.  This works fine for most cases, but it can
be potentially problematic for a hotplug device like USB-audio.  Due
to the nature of snd_card_free_when_closed(), the card free isn't
called immediately after the driver removal for a hotplug device, but
it's left until the last fd is closed.  It implies that the card
debugfs entries also remain.  Meanwhile, when a new device is inserted
before the last close and the very same card slot is assigned, the
driver tries to create the card debugfs root again on the very same
path.  This conflicts with the remaining entry, and results in the
kernel warning such as:
  debugfs: Directory 'card0' with parent 'sound' already present!
with the missing debugfs entry afterwards.

For avoiding such conflicts, remove debugfs entries at the device
disconnection phase instead.  The jack kctl debugfs entries get
removed in snd_jack_dev_disconnect() instead of each kctl
private_free.

Fixes: 2d670ea2bd ("ALSA: jack: implement software jack injection via debugfs")
Link: https://lore.kernel.org/r/20240524151256.32521-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-05-27 09:28:21 +02:00

694 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Jack abstraction layer
*
* Copyright 2008 Wolfson Microelectronics
*/
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/debugfs.h>
#include <sound/jack.h>
#include <sound/core.h>
#include <sound/control.h>
struct snd_jack_kctl {
struct snd_kcontrol *kctl;
struct list_head list; /* list of controls belong to the same jack */
unsigned int mask_bits; /* only masked status bits are reported via kctl */
struct snd_jack *jack; /* pointer to struct snd_jack */
bool sw_inject_enable; /* allow to inject plug event via debugfs */
#ifdef CONFIG_SND_JACK_INJECTION_DEBUG
struct dentry *jack_debugfs_root; /* jack_kctl debugfs root */
#endif
};
#ifdef CONFIG_SND_JACK_INPUT_DEV
static const int jack_switch_types[SND_JACK_SWITCH_TYPES] = {
SW_HEADPHONE_INSERT,
SW_MICROPHONE_INSERT,
SW_LINEOUT_INSERT,
SW_JACK_PHYSICAL_INSERT,
SW_VIDEOOUT_INSERT,
SW_LINEIN_INSERT,
};
#endif /* CONFIG_SND_JACK_INPUT_DEV */
static void snd_jack_remove_debugfs(struct snd_jack *jack);
static int snd_jack_dev_disconnect(struct snd_device *device)
{
struct snd_jack *jack = device->device_data;
snd_jack_remove_debugfs(jack);
#ifdef CONFIG_SND_JACK_INPUT_DEV
guard(mutex)(&jack->input_dev_lock);
if (!jack->input_dev)
return 0;
/* If the input device is registered with the input subsystem
* then we need to use a different deallocator. */
if (jack->registered)
input_unregister_device(jack->input_dev);
else
input_free_device(jack->input_dev);
jack->input_dev = NULL;
#endif /* CONFIG_SND_JACK_INPUT_DEV */
return 0;
}
static int snd_jack_dev_free(struct snd_device *device)
{
struct snd_jack *jack = device->device_data;
struct snd_card *card = device->card;
struct snd_jack_kctl *jack_kctl, *tmp_jack_kctl;
list_for_each_entry_safe(jack_kctl, tmp_jack_kctl, &jack->kctl_list, list) {
list_del_init(&jack_kctl->list);
snd_ctl_remove(card, jack_kctl->kctl);
}
if (jack->private_free)
jack->private_free(jack);
snd_jack_dev_disconnect(device);
kfree(jack->id);
kfree(jack);
return 0;
}
#ifdef CONFIG_SND_JACK_INPUT_DEV
static int snd_jack_dev_register(struct snd_device *device)
{
struct snd_jack *jack = device->device_data;
struct snd_card *card = device->card;
int err, i;
snprintf(jack->name, sizeof(jack->name), "%s %s",
card->shortname, jack->id);
guard(mutex)(&jack->input_dev_lock);
if (!jack->input_dev)
return 0;
jack->input_dev->name = jack->name;
/* Default to the sound card device. */
if (!jack->input_dev->dev.parent)
jack->input_dev->dev.parent = snd_card_get_device_link(card);
/* Add capabilities for any keys that are enabled */
for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
int testbit = SND_JACK_BTN_0 >> i;
if (!(jack->type & testbit))
continue;
if (!jack->key[i])
jack->key[i] = BTN_0 + i;
input_set_capability(jack->input_dev, EV_KEY, jack->key[i]);
}
err = input_register_device(jack->input_dev);
if (err == 0)
jack->registered = 1;
return err;
}
#endif /* CONFIG_SND_JACK_INPUT_DEV */
#ifdef CONFIG_SND_JACK_INJECTION_DEBUG
static void snd_jack_inject_report(struct snd_jack_kctl *jack_kctl, int status)
{
struct snd_jack *jack;
#ifdef CONFIG_SND_JACK_INPUT_DEV
int i;
#endif
if (!jack_kctl)
return;
jack = jack_kctl->jack;
if (jack_kctl->sw_inject_enable)
snd_kctl_jack_report(jack->card, jack_kctl->kctl,
status & jack_kctl->mask_bits);
#ifdef CONFIG_SND_JACK_INPUT_DEV
if (!jack->input_dev)
return;
for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
int testbit = ((SND_JACK_BTN_0 >> i) & jack_kctl->mask_bits);
if (jack->type & testbit)
input_report_key(jack->input_dev, jack->key[i],
status & testbit);
}
for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
int testbit = ((1 << i) & jack_kctl->mask_bits);
if (jack->type & testbit)
input_report_switch(jack->input_dev,
jack_switch_types[i],
status & testbit);
}
input_sync(jack->input_dev);
#endif /* CONFIG_SND_JACK_INPUT_DEV */
}
static ssize_t sw_inject_enable_read(struct file *file,
char __user *to, size_t count, loff_t *ppos)
{
struct snd_jack_kctl *jack_kctl = file->private_data;
int len, ret;
char buf[128];
len = scnprintf(buf, sizeof(buf), "%s: %s\t\t%s: %i\n", "Jack", jack_kctl->kctl->id.name,
"Inject Enabled", jack_kctl->sw_inject_enable);
ret = simple_read_from_buffer(to, count, ppos, buf, len);
return ret;
}
static ssize_t sw_inject_enable_write(struct file *file,
const char __user *from, size_t count, loff_t *ppos)
{
struct snd_jack_kctl *jack_kctl = file->private_data;
int ret, err;
unsigned long enable;
char buf[8] = { 0 };
ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, from, count);
err = kstrtoul(buf, 0, &enable);
if (err)
return err;
if (jack_kctl->sw_inject_enable == (!!enable))
return ret;
jack_kctl->sw_inject_enable = !!enable;
if (!jack_kctl->sw_inject_enable)
snd_jack_report(jack_kctl->jack, jack_kctl->jack->hw_status_cache);
return ret;
}
static ssize_t jackin_inject_write(struct file *file,
const char __user *from, size_t count, loff_t *ppos)
{
struct snd_jack_kctl *jack_kctl = file->private_data;
int ret, err;
unsigned long enable;
char buf[8] = { 0 };
if (!jack_kctl->sw_inject_enable)
return -EINVAL;
ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, from, count);
err = kstrtoul(buf, 0, &enable);
if (err)
return err;
snd_jack_inject_report(jack_kctl, !!enable ? jack_kctl->mask_bits : 0);
return ret;
}
static ssize_t jack_kctl_id_read(struct file *file,
char __user *to, size_t count, loff_t *ppos)
{
struct snd_jack_kctl *jack_kctl = file->private_data;
char buf[64];
int len, ret;
len = scnprintf(buf, sizeof(buf), "%s\n", jack_kctl->kctl->id.name);
ret = simple_read_from_buffer(to, count, ppos, buf, len);
return ret;
}
/* the bit definition is aligned with snd_jack_types in jack.h */
static const char * const jack_events_name[] = {
"HEADPHONE(0x0001)", "MICROPHONE(0x0002)", "LINEOUT(0x0004)",
"MECHANICAL(0x0008)", "VIDEOOUT(0x0010)", "LINEIN(0x0020)",
"", "", "", "BTN_5(0x0200)", "BTN_4(0x0400)", "BTN_3(0x0800)",
"BTN_2(0x1000)", "BTN_1(0x2000)", "BTN_0(0x4000)", "",
};
/* the recommended buffer size is 256 */
static int parse_mask_bits(unsigned int mask_bits, char *buf, size_t buf_size)
{
int i;
scnprintf(buf, buf_size, "0x%04x", mask_bits);
for (i = 0; i < ARRAY_SIZE(jack_events_name); i++)
if (mask_bits & (1 << i)) {
strlcat(buf, " ", buf_size);
strlcat(buf, jack_events_name[i], buf_size);
}
strlcat(buf, "\n", buf_size);
return strlen(buf);
}
static ssize_t jack_kctl_mask_bits_read(struct file *file,
char __user *to, size_t count, loff_t *ppos)
{
struct snd_jack_kctl *jack_kctl = file->private_data;
char buf[256];
int len, ret;
len = parse_mask_bits(jack_kctl->mask_bits, buf, sizeof(buf));
ret = simple_read_from_buffer(to, count, ppos, buf, len);
return ret;
}
static ssize_t jack_kctl_status_read(struct file *file,
char __user *to, size_t count, loff_t *ppos)
{
struct snd_jack_kctl *jack_kctl = file->private_data;
char buf[16];
int len, ret;
len = scnprintf(buf, sizeof(buf), "%s\n", jack_kctl->kctl->private_value ?
"Plugged" : "Unplugged");
ret = simple_read_from_buffer(to, count, ppos, buf, len);
return ret;
}
#ifdef CONFIG_SND_JACK_INPUT_DEV
static ssize_t jack_type_read(struct file *file,
char __user *to, size_t count, loff_t *ppos)
{
struct snd_jack_kctl *jack_kctl = file->private_data;
char buf[256];
int len, ret;
len = parse_mask_bits(jack_kctl->jack->type, buf, sizeof(buf));
ret = simple_read_from_buffer(to, count, ppos, buf, len);
return ret;
}
static const struct file_operations jack_type_fops = {
.open = simple_open,
.read = jack_type_read,
.llseek = default_llseek,
};
#endif
static const struct file_operations sw_inject_enable_fops = {
.open = simple_open,
.read = sw_inject_enable_read,
.write = sw_inject_enable_write,
.llseek = default_llseek,
};
static const struct file_operations jackin_inject_fops = {
.open = simple_open,
.write = jackin_inject_write,
.llseek = default_llseek,
};
static const struct file_operations jack_kctl_id_fops = {
.open = simple_open,
.read = jack_kctl_id_read,
.llseek = default_llseek,
};
static const struct file_operations jack_kctl_mask_bits_fops = {
.open = simple_open,
.read = jack_kctl_mask_bits_read,
.llseek = default_llseek,
};
static const struct file_operations jack_kctl_status_fops = {
.open = simple_open,
.read = jack_kctl_status_read,
.llseek = default_llseek,
};
static int snd_jack_debugfs_add_inject_node(struct snd_jack *jack,
struct snd_jack_kctl *jack_kctl)
{
char *tname;
int i;
/* Don't create injection interface for Phantom jacks */
if (strstr(jack_kctl->kctl->id.name, "Phantom"))
return 0;
tname = kstrdup(jack_kctl->kctl->id.name, GFP_KERNEL);
if (!tname)
return -ENOMEM;
/* replace the chars which are not suitable for folder's name with _ */
for (i = 0; tname[i]; i++)
if (!isalnum(tname[i]))
tname[i] = '_';
jack_kctl->jack_debugfs_root = debugfs_create_dir(tname, jack->card->debugfs_root);
kfree(tname);
debugfs_create_file("sw_inject_enable", 0644, jack_kctl->jack_debugfs_root, jack_kctl,
&sw_inject_enable_fops);
debugfs_create_file("jackin_inject", 0200, jack_kctl->jack_debugfs_root, jack_kctl,
&jackin_inject_fops);
debugfs_create_file("kctl_id", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
&jack_kctl_id_fops);
debugfs_create_file("mask_bits", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
&jack_kctl_mask_bits_fops);
debugfs_create_file("status", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
&jack_kctl_status_fops);
#ifdef CONFIG_SND_JACK_INPUT_DEV
debugfs_create_file("type", 0444, jack_kctl->jack_debugfs_root, jack_kctl,
&jack_type_fops);
#endif
return 0;
}
static void snd_jack_remove_debugfs(struct snd_jack *jack)
{
struct snd_jack_kctl *jack_kctl;
list_for_each_entry(jack_kctl, &jack->kctl_list, list) {
debugfs_remove(jack_kctl->jack_debugfs_root);
jack_kctl->jack_debugfs_root = NULL;
}
}
#else /* CONFIG_SND_JACK_INJECTION_DEBUG */
static int snd_jack_debugfs_add_inject_node(struct snd_jack *jack,
struct snd_jack_kctl *jack_kctl)
{
return 0;
}
static void snd_jack_remove_debugfs(struct snd_jack *jack)
{
}
#endif /* CONFIG_SND_JACK_INJECTION_DEBUG */
static void snd_jack_kctl_private_free(struct snd_kcontrol *kctl)
{
struct snd_jack_kctl *jack_kctl;
jack_kctl = kctl->private_data;
if (jack_kctl) {
list_del(&jack_kctl->list);
kfree(jack_kctl);
}
}
static void snd_jack_kctl_add(struct snd_jack *jack, struct snd_jack_kctl *jack_kctl)
{
jack_kctl->jack = jack;
list_add_tail(&jack_kctl->list, &jack->kctl_list);
snd_jack_debugfs_add_inject_node(jack, jack_kctl);
}
static struct snd_jack_kctl * snd_jack_kctl_new(struct snd_card *card, const char *name, unsigned int mask)
{
struct snd_kcontrol *kctl;
struct snd_jack_kctl *jack_kctl;
int err;
kctl = snd_kctl_jack_new(name, card);
if (!kctl)
return NULL;
err = snd_ctl_add(card, kctl);
if (err < 0)
return NULL;
jack_kctl = kzalloc(sizeof(*jack_kctl), GFP_KERNEL);
if (!jack_kctl)
goto error;
jack_kctl->kctl = kctl;
jack_kctl->mask_bits = mask;
kctl->private_data = jack_kctl;
kctl->private_free = snd_jack_kctl_private_free;
return jack_kctl;
error:
snd_ctl_free_one(kctl);
return NULL;
}
/**
* snd_jack_add_new_kctl - Create a new snd_jack_kctl and add it to jack
* @jack: the jack instance which the kctl will attaching to
* @name: the name for the snd_kcontrol object
* @mask: a bitmask of enum snd_jack_type values that can be detected
* by this snd_jack_kctl object.
*
* Creates a new snd_kcontrol object and adds it to the jack kctl_list.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_jack_add_new_kctl(struct snd_jack *jack, const char * name, int mask)
{
struct snd_jack_kctl *jack_kctl;
jack_kctl = snd_jack_kctl_new(jack->card, name, mask);
if (!jack_kctl)
return -ENOMEM;
snd_jack_kctl_add(jack, jack_kctl);
return 0;
}
EXPORT_SYMBOL(snd_jack_add_new_kctl);
/**
* snd_jack_new - Create a new jack
* @card: the card instance
* @id: an identifying string for this jack
* @type: a bitmask of enum snd_jack_type values that can be detected by
* this jack
* @jjack: Used to provide the allocated jack object to the caller.
* @initial_kctl: if true, create a kcontrol and add it to the jack list.
* @phantom_jack: Don't create a input device for phantom jacks.
*
* Creates a new jack object.
*
* Return: Zero if successful, or a negative error code on failure.
* On success @jjack will be initialised.
*/
int snd_jack_new(struct snd_card *card, const char *id, int type,
struct snd_jack **jjack, bool initial_kctl, bool phantom_jack)
{
struct snd_jack *jack;
struct snd_jack_kctl *jack_kctl = NULL;
int err;
static const struct snd_device_ops ops = {
.dev_free = snd_jack_dev_free,
#ifdef CONFIG_SND_JACK_INPUT_DEV
.dev_register = snd_jack_dev_register,
#endif /* CONFIG_SND_JACK_INPUT_DEV */
.dev_disconnect = snd_jack_dev_disconnect,
};
if (initial_kctl) {
jack_kctl = snd_jack_kctl_new(card, id, type);
if (!jack_kctl)
return -ENOMEM;
}
jack = kzalloc(sizeof(struct snd_jack), GFP_KERNEL);
if (jack == NULL)
return -ENOMEM;
jack->id = kstrdup(id, GFP_KERNEL);
if (jack->id == NULL) {
kfree(jack);
return -ENOMEM;
}
#ifdef CONFIG_SND_JACK_INPUT_DEV
mutex_init(&jack->input_dev_lock);
/* don't create input device for phantom jack */
if (!phantom_jack) {
int i;
jack->input_dev = input_allocate_device();
if (jack->input_dev == NULL) {
err = -ENOMEM;
goto fail_input;
}
jack->input_dev->phys = "ALSA";
jack->type = type;
for (i = 0; i < SND_JACK_SWITCH_TYPES; i++)
if (type & (1 << i))
input_set_capability(jack->input_dev, EV_SW,
jack_switch_types[i]);
}
#endif /* CONFIG_SND_JACK_INPUT_DEV */
err = snd_device_new(card, SNDRV_DEV_JACK, jack, &ops);
if (err < 0)
goto fail_input;
jack->card = card;
INIT_LIST_HEAD(&jack->kctl_list);
if (initial_kctl)
snd_jack_kctl_add(jack, jack_kctl);
*jjack = jack;
return 0;
fail_input:
#ifdef CONFIG_SND_JACK_INPUT_DEV
input_free_device(jack->input_dev);
#endif
kfree(jack->id);
kfree(jack);
return err;
}
EXPORT_SYMBOL(snd_jack_new);
#ifdef CONFIG_SND_JACK_INPUT_DEV
/**
* snd_jack_set_parent - Set the parent device for a jack
*
* @jack: The jack to configure
* @parent: The device to set as parent for the jack.
*
* Set the parent for the jack devices in the device tree. This
* function is only valid prior to registration of the jack. If no
* parent is configured then the parent device will be the sound card.
*/
void snd_jack_set_parent(struct snd_jack *jack, struct device *parent)
{
WARN_ON(jack->registered);
guard(mutex)(&jack->input_dev_lock);
if (jack->input_dev)
jack->input_dev->dev.parent = parent;
}
EXPORT_SYMBOL(snd_jack_set_parent);
/**
* snd_jack_set_key - Set a key mapping on a jack
*
* @jack: The jack to configure
* @type: Jack report type for this key
* @keytype: Input layer key type to be reported
*
* Map a SND_JACK_BTN_* button type to an input layer key, allowing
* reporting of keys on accessories via the jack abstraction. If no
* mapping is provided but keys are enabled in the jack type then
* BTN_n numeric buttons will be reported.
*
* If jacks are not reporting via the input API this call will have no
* effect.
*
* Note that this is intended to be use by simple devices with small
* numbers of keys that can be reported. It is also possible to
* access the input device directly - devices with complex input
* capabilities on accessories should consider doing this rather than
* using this abstraction.
*
* This function may only be called prior to registration of the jack.
*
* Return: Zero if successful, or a negative error code on failure.
*/
int snd_jack_set_key(struct snd_jack *jack, enum snd_jack_types type,
int keytype)
{
int key = fls(SND_JACK_BTN_0) - fls(type);
WARN_ON(jack->registered);
if (!keytype || key >= ARRAY_SIZE(jack->key))
return -EINVAL;
jack->type |= type;
jack->key[key] = keytype;
return 0;
}
EXPORT_SYMBOL(snd_jack_set_key);
#endif /* CONFIG_SND_JACK_INPUT_DEV */
/**
* snd_jack_report - Report the current status of a jack
* Note: This function uses mutexes and should be called from a
* context which can sleep (such as a workqueue).
*
* @jack: The jack to report status for
* @status: The current status of the jack
*/
void snd_jack_report(struct snd_jack *jack, int status)
{
struct snd_jack_kctl *jack_kctl;
unsigned int mask_bits = 0;
#ifdef CONFIG_SND_JACK_INPUT_DEV
struct input_dev *idev;
int i;
#endif
if (!jack)
return;
jack->hw_status_cache = status;
list_for_each_entry(jack_kctl, &jack->kctl_list, list)
if (jack_kctl->sw_inject_enable)
mask_bits |= jack_kctl->mask_bits;
else
snd_kctl_jack_report(jack->card, jack_kctl->kctl,
status & jack_kctl->mask_bits);
#ifdef CONFIG_SND_JACK_INPUT_DEV
idev = input_get_device(jack->input_dev);
if (!idev)
return;
for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
int testbit = ((SND_JACK_BTN_0 >> i) & ~mask_bits);
if (jack->type & testbit)
input_report_key(idev, jack->key[i],
status & testbit);
}
for (i = 0; i < ARRAY_SIZE(jack_switch_types); i++) {
int testbit = ((1 << i) & ~mask_bits);
if (jack->type & testbit)
input_report_switch(idev,
jack_switch_types[i],
status & testbit);
}
input_sync(idev);
input_put_device(idev);
#endif /* CONFIG_SND_JACK_INPUT_DEV */
}
EXPORT_SYMBOL(snd_jack_report);