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[ALSA] Control API - more robust TLV implementation
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- added callback option
- added READ/WRITE/COMMAND flags to access member
- added WRITE/COMMAND ioctls
- added SNDRV_CTL_EVENT_MASK_TLV for TLV change notifications
- added TLV support to ELEM_ADD ioctl

Signed-off-by: Jaroslav Kysela <perex@suse.cz>
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Jaroslav Kysela committed Sep 23, 2006
1 parent 6bbe13e commit 8aa9b58
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Showing 3 changed files with 132 additions and 33 deletions.
10 changes: 9 additions & 1 deletion include/sound/asound.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -727,10 +727,15 @@ typedef int __bitwise snd_ctl_elem_iface_t;
#define SNDRV_CTL_ELEM_ACCESS_WRITE (1<<1)
#define SNDRV_CTL_ELEM_ACCESS_READWRITE (SNDRV_CTL_ELEM_ACCESS_READ|SNDRV_CTL_ELEM_ACCESS_WRITE)
#define SNDRV_CTL_ELEM_ACCESS_VOLATILE (1<<2) /* control value may be changed without a notification */
#define SNDRV_CTL_ELEM_ACCESS_TIMESTAMP (1<<2) /* when was control changed */
#define SNDRV_CTL_ELEM_ACCESS_TIMESTAMP (1<<3) /* when was control changed */
#define SNDRV_CTL_ELEM_ACCESS_TLV_READ (1<<4) /* TLV read is possible */
#define SNDRV_CTL_ELEM_ACCESS_TLV_WRITE (1<<5) /* TLV write is possible */
#define SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE (SNDRV_CTL_ELEM_ACCESS_TLV_READ|SNDRV_CTL_ELEM_ACCESS_TLV_WRITE)
#define SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND (1<<6) /* TLV command is possible */
#define SNDRV_CTL_ELEM_ACCESS_INACTIVE (1<<8) /* control does actually nothing, but may be updated */
#define SNDRV_CTL_ELEM_ACCESS_LOCK (1<<9) /* write lock */
#define SNDRV_CTL_ELEM_ACCESS_OWNER (1<<10) /* write lock owner */
#define SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK (1<<28) /* kernel use a TLV callback */
#define SNDRV_CTL_ELEM_ACCESS_USER (1<<29) /* user space element */
#define SNDRV_CTL_ELEM_ACCESS_DINDIRECT (1<<30) /* indirect access for matrix dimensions in the info structure */
#define SNDRV_CTL_ELEM_ACCESS_INDIRECT (1<<31) /* indirect access for element value in the value structure */
Expand Down Expand Up @@ -838,6 +843,8 @@ enum {
SNDRV_CTL_IOCTL_ELEM_REPLACE = _IOWR('U', 0x18, struct snd_ctl_elem_info),
SNDRV_CTL_IOCTL_ELEM_REMOVE = _IOWR('U', 0x19, struct snd_ctl_elem_id),
SNDRV_CTL_IOCTL_TLV_READ = _IOWR('U', 0x1a, struct snd_ctl_tlv),
SNDRV_CTL_IOCTL_TLV_WRITE = _IOWR('U', 0x1b, struct snd_ctl_tlv),
SNDRV_CTL_IOCTL_TLV_COMMAND = _IOWR('U', 0x1c, struct snd_ctl_tlv),
SNDRV_CTL_IOCTL_HWDEP_NEXT_DEVICE = _IOWR('U', 0x20, int),
SNDRV_CTL_IOCTL_HWDEP_INFO = _IOR('U', 0x21, struct snd_hwdep_info),
SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE = _IOR('U', 0x30, int),
Expand All @@ -862,6 +869,7 @@ enum sndrv_ctl_event_type {
#define SNDRV_CTL_EVENT_MASK_VALUE (1<<0) /* element value was changed */
#define SNDRV_CTL_EVENT_MASK_INFO (1<<1) /* element info was changed */
#define SNDRV_CTL_EVENT_MASK_ADD (1<<2) /* element was added */
#define SNDRV_CTL_EVENT_MASK_TLV (1<<3) /* element TLV tree was changed */
#define SNDRV_CTL_EVENT_MASK_REMOVE (~0U) /* element was removed */

struct snd_ctl_event {
Expand Down
16 changes: 14 additions & 2 deletions include/sound/control.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,11 @@ struct snd_kcontrol;
typedef int (snd_kcontrol_info_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo);
typedef int (snd_kcontrol_get_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
typedef int (snd_kcontrol_put_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
typedef int (snd_kcontrol_tlv_rw_t)(struct snd_kcontrol *kcontrol,
int op_flag, /* 0=read,1=write,-1=command */
unsigned int size,
unsigned int __user *tlv);


struct snd_kcontrol_new {
snd_ctl_elem_iface_t iface; /* interface identifier */
Expand All @@ -42,7 +47,10 @@ struct snd_kcontrol_new {
snd_kcontrol_info_t *info;
snd_kcontrol_get_t *get;
snd_kcontrol_put_t *put;
unsigned int *tlv;
union {
snd_kcontrol_tlv_rw_t *c;
unsigned int *p;
} tlv;
unsigned long private_value;
};

Expand All @@ -59,7 +67,11 @@ struct snd_kcontrol {
snd_kcontrol_info_t *info;
snd_kcontrol_get_t *get;
snd_kcontrol_put_t *put;
unsigned int *tlv;
snd_kcontrol_tlv_rw_t *tlv_rw;
union {
snd_kcontrol_tlv_rw_t *c;
unsigned int *p;
} tlv;
unsigned long private_value;
void *private_data;
void (*private_free)(struct snd_kcontrol *kcontrol);
Expand Down
139 changes: 109 additions & 30 deletions sound/core/control.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -236,12 +236,16 @@ struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
kctl.id.index = ncontrol->index;
kctl.count = ncontrol->count ? ncontrol->count : 1;
access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
(ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|SNDRV_CTL_ELEM_ACCESS_INACTIVE|
SNDRV_CTL_ELEM_ACCESS_DINDIRECT|SNDRV_CTL_ELEM_ACCESS_INDIRECT));
(ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
SNDRV_CTL_ELEM_ACCESS_INACTIVE|
SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
SNDRV_CTL_ELEM_ACCESS_INDIRECT|
SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
kctl.info = ncontrol->info;
kctl.get = ncontrol->get;
kctl.put = ncontrol->put;
kctl.tlv = ncontrol->tlv;
kctl.tlv.p = ncontrol->tlv.p;
kctl.private_value = ncontrol->private_value;
kctl.private_data = private_data;
return snd_ctl_new(&kctl, access);
Expand Down Expand Up @@ -883,6 +887,8 @@ struct user_element {
struct snd_ctl_elem_info info;
void *elem_data; /* element data */
unsigned long elem_data_size; /* size of element data in bytes */
void *tlv_data; /* TLV data */
unsigned long tlv_data_size; /* TLV data size */
void *priv_data; /* private data (like strings for enumerated type) */
unsigned long priv_data_size; /* size of private data in bytes */
};
Expand Down Expand Up @@ -917,9 +923,46 @@ static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
return change;
}

static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
int op_flag,
unsigned int size,
unsigned int __user *tlv)
{
struct user_element *ue = kcontrol->private_data;
int change = 0;
void *new_data;

if (op_flag > 0) {
if (size > 1024 * 128) /* sane value */
return -EINVAL;
new_data = kmalloc(size, GFP_KERNEL);
if (new_data == NULL)
return -ENOMEM;
if (copy_from_user(new_data, tlv, size)) {
kfree(new_data);
return -EFAULT;
}
change = ue->tlv_data_size != size;
if (!change)
change = memcmp(ue->tlv_data, new_data, size);
kfree(ue->tlv_data);
ue->tlv_data = new_data;
ue->tlv_data_size = size;
} else {
if (size < ue->tlv_data_size)
return -ENOSPC;
if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
return -EFAULT;
}
return change;
}

static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
{
kfree(kcontrol->private_data);
struct user_element *ue = kcontrol->private_data;
if (ue->tlv_data)
kfree(ue->tlv_data);
kfree(ue);
}

static int snd_ctl_elem_add(struct snd_ctl_file *file,
Expand All @@ -938,7 +981,8 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
return -EINVAL;
access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
SNDRV_CTL_ELEM_ACCESS_INACTIVE));
SNDRV_CTL_ELEM_ACCESS_INACTIVE|
SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
info->id.numid = 0;
memset(&kctl, 0, sizeof(kctl));
down_write(&card->controls_rwsem);
Expand All @@ -964,6 +1008,10 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
kctl.get = snd_ctl_elem_user_get;
if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
kctl.put = snd_ctl_elem_user_put;
if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
kctl.tlv.c = snd_ctl_elem_user_tlv;
access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
}
switch (info->type) {
case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
private_size = sizeof(char);
Expand Down Expand Up @@ -1068,38 +1116,65 @@ static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
return 0;
}

static int snd_ctl_tlv_read(struct snd_card *card,
struct snd_ctl_tlv __user *_tlv)
static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
struct snd_ctl_tlv __user *_tlv,
int op_flag)
{
struct snd_card *card = file->card;
struct snd_ctl_tlv tlv;
struct snd_kcontrol *kctl;
struct snd_kcontrol_volatile *vd;
unsigned int len;
int err = 0;

if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
return -EFAULT;
if (tlv.length < sizeof(unsigned int) * 3)
return -EINVAL;
down_read(&card->controls_rwsem);
kctl = snd_ctl_find_numid(card, tlv.numid);
if (kctl == NULL) {
err = -ENOENT;
goto __kctl_end;
}
if (kctl->tlv == NULL) {
err = -ENXIO;
goto __kctl_end;
}
len = kctl->tlv[1] + 2 * sizeof(unsigned int);
if (tlv.length < len) {
err = -ENOMEM;
goto __kctl_end;
}
if (copy_to_user(_tlv->tlv, kctl->tlv, len))
err = -EFAULT;
if (tlv.length < sizeof(unsigned int) * 3)
return -EINVAL;
down_read(&card->controls_rwsem);
kctl = snd_ctl_find_numid(card, tlv.numid);
if (kctl == NULL) {
err = -ENOENT;
goto __kctl_end;
}
if (kctl->tlv.p == NULL) {
err = -ENXIO;
goto __kctl_end;
}
vd = &kctl->vd[tlv.numid - kctl->id.numid];
if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
(op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
(op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
err = -ENXIO;
goto __kctl_end;
}
if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
if (file && vd->owner != NULL && vd->owner != file) {
err = -EPERM;
goto __kctl_end;
}
err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv);
if (err > 0) {
up_read(&card->controls_rwsem);
snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
return 0;
}
} else {
if (op_flag) {
err = -ENXIO;
goto __kctl_end;
}
len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
if (tlv.length < len) {
err = -ENOMEM;
goto __kctl_end;
}
if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
err = -EFAULT;
}
__kctl_end:
up_read(&card->controls_rwsem);
return err;
up_read(&card->controls_rwsem);
return err;
}

static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Expand Down Expand Up @@ -1140,8 +1215,12 @@ static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg
return snd_ctl_elem_remove(ctl, argp);
case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
return snd_ctl_subscribe_events(ctl, ip);
case SNDRV_CTL_IOCTL_TLV_READ:
return snd_ctl_tlv_read(card, argp);
case SNDRV_CTL_IOCTL_TLV_READ:
return snd_ctl_tlv_ioctl(ctl, argp, 0);
case SNDRV_CTL_IOCTL_TLV_WRITE:
return snd_ctl_tlv_ioctl(ctl, argp, 1);
case SNDRV_CTL_IOCTL_TLV_COMMAND:
return snd_ctl_tlv_ioctl(ctl, argp, -1);
case SNDRV_CTL_IOCTL_POWER:
return -ENOPROTOOPT;
case SNDRV_CTL_IOCTL_POWER_STATE:
Expand Down

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