[ALSA] Control API - more robust TLV implementation

- 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>

diff --git a/include/sound/asound.h b/include/sound/asound.h
index 76a2040..c1621c6 100644 (file)
--- a/include/sound/asound.h
+++ b/include/sound/asound.h
@@ -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 */
@@ -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),
@@ -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 {

diff --git a/include/sound/control.h b/include/sound/control.h
index a93a58d..e3905c5 100644 (file)
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -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 */
@@ -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;
 };
 
@@ -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);

diff --git a/sound/core/control.c b/sound/core/control.c
index f0c7272..31ad581 100644 (file)
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -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);
@@ -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 */
 };
@@ -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,
@@ -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);
@@ -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);
@@ -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)
@@ -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: