shared/vcp: Add initial code for handling VCP
authorSathish Narasimman <sathish.narasimman@intel.com>
Mon, 19 Sep 2022 08:07:20 +0000 (13:37 +0530)
committerAyush Garg <ayush.garg@samsung.com>
Mon, 15 May 2023 09:25:54 +0000 (14:55 +0530)
This adds initial code for Volume Control Profile.

Change-Id: I95452360c7963470ca535eb7fb47f162fff5a86d
Signed-off-by: Manika Shrivastava <manika.sh@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>
Makefile.am
src/shared/vcp.c [new file with mode: 0644]
src/shared/vcp.h [new file with mode: 0644]

index 10c3fda..520801f 100755 (executable)
@@ -213,6 +213,7 @@ shared_sources = src/shared/io.h src/shared/timeout.h \
                        src/shared/gap.h src/shared/gap.c \
                        src/shared/log.h src/shared/log.c \
                        src/shared/bap.h src/shared/bap.c src/shared/ascs.h \
+                       src/shared/vcp.c src/shared/vcp.h \
                        src/shared/lc3.h src/shared/tty.h
 
 if READLINE
diff --git a/src/shared/vcp.c b/src/shared/vcp.c
new file mode 100644 (file)
index 0000000..d22103c
--- /dev/null
@@ -0,0 +1,1103 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2022  Intel Corporation. All rights reserved.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <inttypes.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "lib/bluetooth.h"
+#include "lib/uuid.h"
+
+#include "src/shared/queue.h"
+#include "src/shared/util.h"
+#include "src/shared/timeout.h"
+#include "src/shared/att.h"
+#include "src/shared/gatt-db.h"
+#include "src/shared/gatt-server.h"
+#include "src/shared/gatt-client.h"
+#include "src/shared/vcp.h"
+#include "src/log.h"
+
+#define VCP_STEP_SIZE 1
+
+/* Apllication Error Code */
+#define BT_ATT_ERROR_INVALID_CHANGE_COUNTER    0x80
+#define BT_ATT_ERROR_OPCODE_NOT_SUPPORTED      0x81
+
+struct bt_vcp_db {
+       struct gatt_db *db;
+       struct bt_vcs *vcs;
+};
+
+typedef void (*vcp_func_t)(struct bt_vcp *vcp, bool success, uint8_t att_ecode,
+                                       const uint8_t *value, uint16_t length,
+                                       void *user_data);
+
+struct bt_vcp_pending {
+       unsigned int id;
+       struct bt_vcp *vcp;
+       vcp_func_t func;
+       void *user_data;
+};
+
+struct bt_vcs_param {
+       uint8_t op;
+       uint8_t change_counter;
+} __packed;
+
+struct bt_vcs_ab_vol {
+       uint8_t change_counter;
+       uint8_t vol_set;
+} __packed;
+
+struct bt_vcp_cb {
+       unsigned int id;
+       bt_vcp_func_t attached;
+       bt_vcp_func_t detached;
+       void *user_data;
+};
+
+typedef void (*vcp_notify_t)(struct bt_vcp *vcp, uint16_t value_handle,
+                               const uint8_t *value, uint16_t length,
+                               void *user_data);
+
+struct bt_vcp_notify {
+       unsigned int id;
+       struct bt_vcp *vcp;
+       vcp_notify_t func;
+       void *user_data;
+};
+
+struct bt_vcp {
+       int ref_count;
+       struct bt_vcp_db *ldb;
+       struct bt_vcp_db *rdb;
+       struct bt_gatt_client *client;
+       struct bt_att *att;
+       unsigned int vstate_id;
+       unsigned int vflag_id;
+
+       struct queue *pending;
+
+       void *debug_data;
+       void *user_data;
+};
+
+#define RESET_VOLUME_SETTING 0x00
+#define USERSET_VOLUME_SETTING 0x01
+
+/* Contains local bt_vcp_db */
+struct vol_state {
+       uint8_t vol_set;
+       uint8_t mute;
+       uint8_t counter;
+} __packed;
+
+struct bt_vcs {
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       uint8_t vol_flag;
+       struct gatt_db_attribute *service;
+       struct gatt_db_attribute *vs;
+       struct gatt_db_attribute *vs_ccc;
+       struct gatt_db_attribute *vol_cp;
+       struct gatt_db_attribute *vf;
+       struct gatt_db_attribute *vf_ccc;
+};
+
+static struct queue *vcp_db;
+static struct queue *vcp_cbs;
+static struct queue *sessions;
+
+static void *iov_pull_mem(struct iovec *iov, size_t len)
+{
+       void *data = iov->iov_base;
+
+       if (iov->iov_len < len)
+               return NULL;
+
+       iov->iov_base += len;
+       iov->iov_len -= len;
+
+       return data;
+}
+
+static struct bt_vcp_db *vcp_get_vdb(struct bt_vcp *vcp)
+{
+       if (!vcp)
+               return NULL;
+
+       if (vcp->ldb)
+               return vcp->ldb;
+
+       return NULL;
+}
+
+static struct vol_state *vdb_get_vstate(struct bt_vcp_db *vdb)
+{
+       if (!vdb->vcs)
+               return NULL;
+
+       if (vdb->vcs->vstate)
+               return vdb->vcs->vstate;
+
+       return NULL;
+}
+
+static struct bt_vcs *vcp_get_vcs(struct bt_vcp *vcp)
+{
+       if (!vcp)
+               return NULL;
+
+       if (vcp->rdb->vcs)
+               return vcp->rdb->vcs;
+
+       vcp->rdb->vcs = new0(struct bt_vcs, 1);
+       vcp->rdb->vcs->vdb = vcp->rdb;
+
+       return vcp->rdb->vcs;
+}
+
+static void vcp_detached(void *data, void *user_data)
+{
+       struct bt_vcp_cb *cb = data;
+       struct bt_vcp *vcp = user_data;
+
+       cb->detached(vcp, cb->user_data);
+}
+
+void bt_vcp_detach(struct bt_vcp *vcp)
+{
+       if (!queue_remove(sessions, vcp))
+               return;
+
+       bt_gatt_client_unref(vcp->client);
+       vcp->client = NULL;
+
+       queue_foreach(vcp_cbs, vcp_detached, vcp);
+}
+
+static void vcp_db_free(void *data)
+{
+       struct bt_vcp_db *vdb = data;
+
+       if (!vdb)
+               return;
+
+       gatt_db_unref(vdb->db);
+
+       free(vdb->vcs);
+       free(vdb);
+}
+
+static void vcp_free(void *data)
+{
+       struct bt_vcp *vcp = data;
+
+       bt_vcp_detach(vcp);
+
+       vcp_db_free(vcp->rdb);
+
+       queue_destroy(vcp->pending, NULL);
+
+       free(vcp);
+}
+bool bt_vcp_set_user_data(struct bt_vcp *vcp, void *user_data)
+{
+       if (!vcp)
+               return false;
+
+       vcp->user_data = user_data;
+
+       return true;
+}
+
+static bool vcp_db_match(const void *data, const void *match_data)
+{
+       const struct bt_vcp_db *vdb = data;
+       const struct gatt_db *db = match_data;
+
+       return (vdb->db == db);
+}
+
+struct bt_att *bt_vcp_get_att(struct bt_vcp *vcp)
+{
+       if (!vcp)
+               return NULL;
+
+       if (vcp->att)
+               return vcp->att;
+
+       return bt_gatt_client_get_att(vcp->client);
+}
+
+struct bt_vcp *bt_vcp_ref(struct bt_vcp *vcp)
+{
+       if (!vcp)
+               return NULL;
+
+       __sync_fetch_and_add(&vcp->ref_count, 1);
+
+       return vcp;
+}
+
+void bt_vcp_unref(struct bt_vcp *vcp)
+{
+       if (!vcp)
+               return;
+
+       if (__sync_sub_and_fetch(&vcp->ref_count, 1))
+               return;
+
+       vcp_free(vcp);
+}
+
+static void vcp_disconnected(int err, void *user_data)
+{
+       struct bt_vcp *vcp = user_data;
+
+       DBG("vcp %p disconnected err %d", vcp, err);
+
+       bt_vcp_detach(vcp);
+}
+
+static struct bt_vcp *vcp_get_session(struct bt_att *att, struct gatt_db *db)
+{
+       const struct queue_entry *entry;
+       struct bt_vcp *vcp;
+
+       for (entry = queue_get_entries(sessions); entry; entry = entry->next) {
+               struct bt_vcp *vcp = entry->data;
+
+               if (att == bt_vcp_get_att(vcp))
+                       return vcp;
+       }
+
+       vcp = bt_vcp_new(db, NULL);
+       vcp->att = att;
+
+       bt_att_register_disconnect(att, vcp_disconnected, vcp, NULL);
+
+       bt_vcp_attach(vcp, NULL);
+
+       return vcp;
+
+}
+
+static uint8_t vcs_rel_vol_down(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                               struct iovec *iov)
+{
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       uint8_t *change_counter;
+
+       DBG("");
+
+       vdb = vcp_get_vdb(vcp);
+       if (!vdb) {
+               DBG("error: VDB not availalbe");
+               return 0;
+       }
+
+       vstate = vdb_get_vstate(vdb);
+       if (!vstate) {
+               DBG("error: VSTATE not availalbe");
+               return 0;
+       }
+
+       change_counter = iov_pull_mem(iov, sizeof(*change_counter));
+       if (!change_counter)
+               return 0;
+
+       if (*change_counter != vstate->counter) {
+               DBG("Change Counter Mismatch Volume not decremented!");
+               return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
+       }
+
+       vstate->vol_set = MAX((vstate->vol_set - VCP_STEP_SIZE), 0);
+       vstate->counter = -~vstate->counter; /*Increment Change Counter*/
+
+       gatt_db_attribute_notify(vdb->vcs->vs, (void *)vstate,
+                                sizeof(struct vol_state),
+                                bt_vcp_get_att(vcp));
+       return 0;
+}
+
+static uint8_t vcs_rel_vol_up(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                               struct iovec *iov)
+{
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       uint8_t *change_counter;
+
+       DBG("");
+
+       vdb = vcp_get_vdb(vcp);
+       if (!vdb) {
+               DBG("error: VDB not availalbe");
+               return 0;
+       }
+
+       vstate = vdb_get_vstate(vdb);
+       if (!vstate) {
+               DBG("error: VCP database not availalbe!!!!");
+               return 0;
+       }
+
+       change_counter = iov_pull_mem(iov, sizeof(*change_counter));
+       if (!change_counter)
+               return 0;
+
+       if (*change_counter != vstate->counter) {
+               DBG("Change Counter Mismatch Volume not decremented!");
+               return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
+       }
+
+       vstate->vol_set = MIN((vstate->vol_set + VCP_STEP_SIZE), 255);
+       vstate->counter = -~vstate->counter; /*Increment Change Counter*/
+
+       gatt_db_attribute_notify(vdb->vcs->vs, (void *)vstate,
+                                sizeof(struct vol_state),
+                                bt_vcp_get_att(vcp));
+       return 0;
+}
+
+static uint8_t vcs_unmute_rel_vol_down(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                               struct iovec *iov)
+{
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       uint8_t *change_counter;
+
+       DBG("");
+
+       vdb = vcp_get_vdb(vcp);
+       if (!vdb) {
+               DBG("error: VDB not availalbe");
+               return 0;
+       }
+
+       vstate = vdb_get_vstate(vdb);
+       if (!vstate) {
+               DBG("error: VCP database not availalbe!!!!");
+               return 0;
+       }
+
+       change_counter = iov_pull_mem(iov, sizeof(*change_counter));
+       if (!change_counter)
+               return 0;
+
+       if (*change_counter != vstate->counter) {
+               DBG("Change Counter Mismatch Volume not decremented!");
+               return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
+       }
+
+       vstate->mute = 0x00;
+       vstate->vol_set = MAX((vstate->vol_set - VCP_STEP_SIZE), 0);
+       vstate->counter = -~vstate->counter; /*Increment Change Counter*/
+
+       gatt_db_attribute_notify(vdb->vcs->vs, (void *)vstate,
+                                sizeof(struct vol_state),
+                                bt_vcp_get_att(vcp));
+       return 0;
+}
+
+static uint8_t vcs_unmute_rel_vol_up(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                               struct iovec *iov)
+{
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       uint8_t *change_counter;
+
+       DBG("");
+
+       vdb = vcp_get_vdb(vcp);
+       if (!vdb) {
+               DBG("error: VDB not availalbe");
+               return 0;
+       }
+
+       vstate = vdb_get_vstate(vdb);
+       if (!vstate) {
+               DBG("error: VSTATE not availalbe");
+               return 0;
+       }
+
+       change_counter = iov_pull_mem(iov, sizeof(*change_counter));
+       if (!change_counter)
+               return 0;
+
+       if (*change_counter != vstate->counter) {
+               DBG("Change Counter Mismatch Volume not decremented!");
+               return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
+       }
+
+       vstate->mute = 0x00;
+       vstate->vol_set = MIN((vstate->vol_set + VCP_STEP_SIZE), 255);
+       vstate->counter = -~vstate->counter; /*Increment Change Counter*/
+
+       gatt_db_attribute_notify(vdb->vcs->vs, (void *)vstate,
+                                sizeof(struct vol_state),
+                                bt_vcp_get_att(vcp));
+       return 0;
+}
+
+static uint8_t vcs_set_absolute_vol(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                               struct iovec *iov)
+{
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       struct bt_vcs_ab_vol *req;
+
+       DBG("");
+
+       vdb = vcp_get_vdb(vcp);
+       if (!vdb) {
+               DBG("error: VDB not availalbe");
+               return 0;
+       }
+
+       vstate = vdb_get_vstate(vdb);
+       if (!vstate) {
+               DBG("error: VSTATE not availalbe");
+               return 0;
+       }
+
+       req = iov_pull_mem(iov, sizeof(*req));
+       if (!req)
+               return 0;
+
+       if (req->change_counter != vstate->counter) {
+               DBG("Change Counter Mismatch Volume not decremented!");
+               return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
+       }
+
+       vstate->vol_set = req->vol_set;
+       vstate->counter = -~vstate->counter; /*Increment Change Counter*/
+
+       gatt_db_attribute_notify(vdb->vcs->vs, (void *)vstate,
+                                sizeof(struct vol_state),
+                                bt_vcp_get_att(vcp));
+       return 0;
+}
+
+static uint8_t vcs_unmute(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                               struct iovec *iov)
+{
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       uint8_t *change_counter;
+
+       DBG("");
+
+       vdb = vcp_get_vdb(vcp);
+       if (!vdb) {
+               DBG("error: VDB not availalbe");
+               return 0;
+       }
+
+       vstate = vdb_get_vstate(vdb);
+       if (!vstate) {
+               DBG("error: VSTATE not availalbe");
+               return 0;
+       }
+
+       change_counter = iov_pull_mem(iov, sizeof(*change_counter));
+       if (!change_counter)
+               return 0;
+
+       if (*change_counter != vstate->counter) {
+               DBG("Change Counter Mismatch Volume not decremented!");
+               return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
+       }
+
+       vstate->mute = 0x00;
+       vstate->counter = -~vstate->counter; /*Increment Change Counter*/
+
+       gatt_db_attribute_notify(vdb->vcs->vs, (void *)vstate,
+                                sizeof(struct vol_state),
+                                bt_vcp_get_att(vcp));
+       return 0;
+}
+
+static uint8_t vcs_mute(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                               struct iovec *iov)
+{
+       struct bt_vcp_db *vdb;
+       struct vol_state *vstate;
+       uint8_t *change_counter;
+
+       DBG("");
+
+       vdb = vcp_get_vdb(vcp);
+       if (!vdb) {
+               DBG("error: VDB not availalbe");
+               return 0;
+       }
+
+       vstate = vdb_get_vstate(vdb);
+       if (!vstate) {
+               DBG("error: VSTATE not availalbe");
+               return 0;
+       }
+
+       change_counter = iov_pull_mem(iov, sizeof(*change_counter));
+       if (!change_counter)
+               return 0;
+
+       if (*change_counter != vstate->counter) {
+               DBG("Change Counter Mismatch Volume not decremented!");
+               return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
+       }
+
+       vstate->mute = 0x01;
+       vstate->counter = -~vstate->counter; /*Increment Change Counter*/
+
+       return 0;
+}
+
+#define        BT_VCS_REL_VOL_DOWN             0x00
+#define        BT_VCS_REL_VOL_UP               0x01
+#define        BT_VCS_UNMUTE_REL_VOL_DOWN      0x02
+#define        BT_VCS_UNMUTE_REL_VOL_UP        0x03
+#define        BT_VCS_SET_ABSOLUTE_VOL         0x04
+#define        BT_VCS_UNMUTE                   0x05
+#define        BT_VCS_MUTE                     0x06
+
+#define VCS_OP(_str, _op, _size, _func) \
+       { \
+               .str = _str, \
+               .op = _op, \
+               .size = _size, \
+               .func = _func, \
+       }
+
+struct vcs_op_handler {
+       const char *str;
+       uint8_t op;
+       size_t  size;
+       uint8_t (*func)(struct bt_vcs *vcs, struct bt_vcp *vcp,
+                       struct iovec *iov);
+} vcp_handlers[] = {
+       VCS_OP("Relative Volume Down", BT_VCS_REL_VOL_DOWN,
+               sizeof(uint8_t), vcs_rel_vol_down),
+       VCS_OP("Relative Volume Up", BT_VCS_REL_VOL_UP,
+               sizeof(uint8_t), vcs_rel_vol_up),
+       VCS_OP("Unmute - Relative Volume Down", BT_VCS_UNMUTE_REL_VOL_DOWN,
+               sizeof(uint8_t), vcs_unmute_rel_vol_down),
+       VCS_OP("Unmute - Relative Volume Up", BT_VCS_UNMUTE_REL_VOL_UP,
+               sizeof(uint8_t), vcs_unmute_rel_vol_up),
+       VCS_OP("Set Absolute Volume", BT_VCS_SET_ABSOLUTE_VOL,
+               sizeof(struct bt_vcs_ab_vol), vcs_set_absolute_vol),
+       VCS_OP("UnMute", BT_VCS_UNMUTE,
+               sizeof(uint8_t), vcs_unmute),
+       VCS_OP("Mute", BT_VCS_MUTE,
+               sizeof(uint8_t), vcs_mute),
+       {}
+};
+
+static void vcs_cp_write(struct gatt_db_attribute *attrib,
+                               unsigned int id, uint16_t offset,
+                               const uint8_t *value, size_t len,
+                               uint8_t opcode, struct bt_att *att,
+                               void *user_data)
+{
+       struct bt_vcs *vcs = user_data;
+       struct bt_vcp *vcp = vcp_get_session(att, vcs->vdb->db);
+       struct iovec iov = {
+               .iov_base = (void *) value,
+               .iov_len = len,
+       };
+       uint8_t *vcp_op;
+       struct vcs_op_handler *handler;
+       uint8_t ret = BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+
+       DBG("");
+
+       if (offset) {
+               DBG("invalid offset %d", offset);
+               ret = BT_ATT_ERROR_INVALID_OFFSET;
+               goto respond;
+       }
+
+       if (len < sizeof(*vcp_op)) {
+               DBG("invalid len %d < %d sizeof(*param)", len,
+                                                       sizeof(*vcp_op));
+               ret = BT_ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LEN;
+               goto respond;
+       }
+
+       vcp_op = iov_pull_mem(&iov, sizeof(*vcp_op));
+
+       DBG("op: %x", *vcp_op);
+
+       for (handler = vcp_handlers; handler && handler->str; handler++) {
+               if (handler->op != *vcp_op)
+                       continue;
+
+               if (iov.iov_len < handler->size) {
+                       DBG("invalid len %d < %d handler->size", len,
+                           handler->size);
+                       ret = BT_ATT_ERROR_OPCODE_NOT_SUPPORTED;
+                       goto respond;
+               }
+
+               break;
+       }
+
+       if (handler && handler->str) {
+               DBG("%s", handler->str);
+
+               ret = handler->func(vcs, vcp, &iov);
+       } else {
+               DBG("Unknown opcode 0x%02x", *vcp_op);
+               ret = BT_ATT_ERROR_OPCODE_NOT_SUPPORTED;
+       }
+
+respond:
+       gatt_db_attribute_write_result(attrib, id, ret);
+}
+
+static void vcs_state_read(struct gatt_db_attribute *attrib,
+                               unsigned int id, uint16_t offset,
+                               uint8_t opcode, struct bt_att *att,
+                               void *user_data)
+{
+       struct bt_vcs *vcs = user_data;
+       struct iovec iov;
+
+       DBG("");
+
+       iov.iov_base = vcs->vstate;
+       iov.iov_len = sizeof(*vcs->vstate);
+
+       gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+                                                       iov.iov_len);
+}
+
+static void vcs_flag_read(struct gatt_db_attribute *attrib,
+                               unsigned int id, uint16_t offset,
+                               uint8_t opcode, struct bt_att *att,
+                               void *user_data)
+{
+       struct bt_vcs *vcs = user_data;
+       struct iovec iov;
+
+       DBG("vf: %x", vcs->vol_flag);
+
+       iov.iov_base = &vcs->vol_flag;
+       iov.iov_len = sizeof(vcs->vol_flag);
+
+       gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+                                                       iov.iov_len);
+}
+
+static struct bt_vcs *vcs_new(struct gatt_db *db)
+{
+       struct bt_vcs *vcs;
+       struct vol_state *vstate;
+       bt_uuid_t uuid;
+
+       if (!db)
+               return NULL;
+
+       vcs = new0(struct bt_vcs, 1);
+
+       vstate = new0(struct vol_state, 1);
+
+       vcs->vstate = vstate;
+       vcs->vol_flag = USERSET_VOLUME_SETTING;
+
+       /* Populate DB with VCS attributes */
+       bt_uuid16_create(&uuid, VCS_UUID);
+       vcs->service = gatt_db_add_service(db, &uuid, true, 9);
+
+       bt_uuid16_create(&uuid, VOL_STATE_CHRC_UUID);
+       vcs->vs = gatt_db_service_add_characteristic(vcs->service,
+                                       &uuid,
+                                       BT_ATT_PERM_READ,
+                                       BT_GATT_CHRC_PROP_READ |
+                                       BT_GATT_CHRC_PROP_NOTIFY,
+                                       vcs_state_read, NULL,
+                                       vcs);
+
+       vcs->vs_ccc = gatt_db_service_add_ccc(vcs->service,
+                                       BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+       bt_uuid16_create(&uuid, VOL_CP_CHRC_UUID);
+       vcs->vol_cp = gatt_db_service_add_characteristic(vcs->service,
+                                       &uuid,
+                                       BT_ATT_PERM_WRITE,
+                                       BT_GATT_CHRC_PROP_WRITE,
+                                       NULL, vcs_cp_write,
+                                       vcs);
+
+       bt_uuid16_create(&uuid, VOL_FLAG_CHRC_UUID);
+       vcs->vf = gatt_db_service_add_characteristic(vcs->service,
+                                       &uuid,
+                                       BT_ATT_PERM_READ,
+                                       BT_GATT_CHRC_PROP_READ |
+                                       BT_GATT_CHRC_PROP_NOTIFY,
+                                       vcs_flag_read, NULL,
+                                       vcs);
+
+       vcs->vf_ccc = gatt_db_service_add_ccc(vcs->service,
+                                       BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+
+       gatt_db_service_set_active(vcs->service, true);
+
+       return vcs;
+}
+
+static struct bt_vcp_db *vcp_db_new(struct gatt_db *db)
+{
+       struct bt_vcp_db *vdb;
+
+       if (!db)
+               return NULL;
+
+       vdb = new0(struct bt_vcp_db, 1);
+       vdb->db = gatt_db_ref(db);
+
+       if (!vcp_db)
+               vcp_db = queue_new();
+
+       vdb->vcs = vcs_new(db);
+       vdb->vcs->vdb = vdb;
+
+       queue_push_tail(vcp_db, vdb);
+
+       return vdb;
+}
+
+static struct bt_vcp_db *vcp_get_db(struct gatt_db *db)
+{
+       struct bt_vcp_db *vdb;
+
+       vdb = queue_find(vcp_db, vcp_db_match, db);
+       if (vdb)
+               return vdb;
+
+       return vcp_db_new(db);
+}
+
+void bt_vcp_add_db(struct gatt_db *db)
+{
+       vcp_db_new(db);
+}
+
+unsigned int bt_vcp_register(bt_vcp_func_t attached, bt_vcp_func_t detached,
+                                                       void *user_data)
+{
+       struct bt_vcp_cb *cb;
+       static unsigned int id;
+
+       if (!attached && !detached)
+               return 0;
+
+       if (!vcp_cbs)
+               vcp_cbs = queue_new();
+
+       cb = new0(struct bt_vcp_cb, 1);
+       cb->id = ++id ? id : ++id;
+       cb->attached = attached;
+       cb->detached = detached;
+       cb->user_data = user_data;
+
+       queue_push_tail(vcp_cbs, cb);
+
+       return cb->id;
+}
+
+static bool match_id(const void *data, const void *match_data)
+{
+       const struct bt_vcp_cb *cb = data;
+       unsigned int id = PTR_TO_UINT(match_data);
+
+       return (cb->id == id);
+}
+
+bool bt_vcp_unregister(unsigned int id)
+{
+       struct bt_vcp_cb *cb;
+
+       cb = queue_remove_if(vcp_cbs, match_id, UINT_TO_PTR(id));
+       if (!cb)
+               return false;
+
+       free(cb);
+
+       return true;
+}
+
+struct bt_vcp *bt_vcp_new(struct gatt_db *ldb, struct gatt_db *rdb)
+{
+       struct bt_vcp *vcp;
+       struct bt_vcp_db *vdb;
+
+       if (!ldb)
+               return NULL;
+
+       vdb = vcp_get_db(ldb);
+       if (!vdb)
+               return NULL;
+
+       vcp = new0(struct bt_vcp, 1);
+       vcp->ldb = vdb;
+       vcp->pending = queue_new();
+
+       if (!rdb)
+               goto done;
+
+       vdb = new0(struct bt_vcp_db, 1);
+       vdb->db = gatt_db_ref(rdb);
+
+       vcp->rdb = vdb;
+
+done:
+       bt_vcp_ref(vcp);
+
+       return vcp;
+}
+
+static void vcp_vstate_register(uint16_t att_ecode, void *user_data)
+{
+       DBG("");
+       if (att_ecode)
+               DBG("VCS register failed: 0x%04x", att_ecode);
+}
+
+static void vcp_vflag_register(uint16_t att_ecode, void *user_data)
+{
+       DBG("");
+       if (att_ecode)
+               DBG("VCS register failed: 0x%04x", att_ecode);
+}
+
+static void vcp_vstate_notify(uint16_t value_handle, const uint8_t *value,
+                               uint16_t length, void *user_data)
+{
+       struct vol_state vstate;
+
+       memcpy(&vstate, value, sizeof(struct vol_state));
+
+       DBG("Vol Settings 0x%x", vstate.vol_set);
+       DBG("Mute Status 0x%x", vstate.mute);
+       DBG("Vol Counter 0x%x", vstate.counter);
+}
+
+static void vcp_vflag_notify(uint16_t value_handle, const uint8_t *value,
+                               uint16_t length, void *user_data)
+{
+       uint8_t vflag;
+
+       memcpy(&vflag, value, sizeof(vflag));
+
+       DBG("Vol Flag 0x%x", vflag);
+}
+
+static void read_vol_flag(struct bt_vcp *vcp, bool success, uint8_t att_ecode,
+                               const uint8_t *value, uint16_t length,
+                               void *user_data)
+{
+       uint8_t *vol_flag;
+       struct iovec iov = {
+               .iov_base = (void *) value,
+               .iov_len = length,
+       };
+
+       if (!success) {
+               DBG("Unable to read VCP Vol State: error 0x%02x", att_ecode);
+               return;
+       }
+
+       vol_flag = iov_pull_mem(&iov, sizeof(*vol_flag));
+       if (!vol_flag) {
+               DBG("Unable to get Vol State");
+               return;
+       }
+
+       DBG("Vol Flag:%x", *vol_flag);
+}
+
+static void read_vol_state(struct bt_vcp *vcp, bool success, uint8_t att_ecode,
+                               const uint8_t *value, uint16_t length,
+                               void *user_data)
+{
+       struct vol_state *vs;
+       struct iovec iov = {
+               .iov_base = (void *) value,
+               .iov_len = length,
+       };
+
+       if (!success) {
+               DBG("Unable to read VCP Vol State: error 0x%02x", att_ecode);
+               return;
+       }
+
+       vs = iov_pull_mem(&iov, sizeof(*vs));
+       if (!vs) {
+               DBG("Unable to get Vol State");
+               return;
+       }
+
+       DBG("Vol Set:%x", vs->vol_set);
+       DBG("Vol Mute:%x", vs->mute);
+       DBG("Vol Counter:%x", vs->counter);
+}
+
+static void vcp_pending_destroy(void *data)
+{
+       struct bt_vcp_pending *pending = data;
+       struct bt_vcp *vcp = pending->vcp;
+
+       if (queue_remove_if(vcp->pending, NULL, pending))
+               free(pending);
+}
+
+static void vcp_pending_complete(bool success, uint8_t att_ecode,
+                               const uint8_t *value, uint16_t length,
+                               void *user_data)
+{
+       struct bt_vcp_pending *pending = user_data;
+
+       if (pending->func)
+               pending->func(pending->vcp, success, att_ecode, value, length,
+                                               pending->user_data);
+}
+
+static void vcp_read_value(struct bt_vcp *vcp, uint16_t value_handle,
+                               vcp_func_t func, void *user_data)
+{
+       struct bt_vcp_pending *pending;
+
+       pending = new0(struct bt_vcp_pending, 1);
+       pending->vcp = vcp;
+       pending->func = func;
+       pending->user_data = user_data;
+
+       pending->id = bt_gatt_client_read_value(vcp->client, value_handle,
+                                               vcp_pending_complete, pending,
+                                               vcp_pending_destroy);
+       if (!pending->id) {
+               DBG("Unable to send Read request");
+               free(pending);
+               return;
+       }
+
+       queue_push_tail(vcp->pending, pending);
+}
+
+static void foreach_vcs_char(struct gatt_db_attribute *attr, void *user_data)
+{
+       struct bt_vcp *vcp = user_data;
+       uint16_t value_handle;
+       bt_uuid_t uuid, uuid_vstate, uuid_cp, uuid_vflag;
+       struct bt_vcs *vcs;
+
+       DBG("");
+       if (!gatt_db_attribute_get_char_data(attr, NULL, &value_handle,
+                                               NULL, NULL, &uuid))
+               return;
+
+       bt_uuid16_create(&uuid_vstate, VOL_STATE_CHRC_UUID);
+       bt_uuid16_create(&uuid_cp, VOL_CP_CHRC_UUID);
+       bt_uuid16_create(&uuid_vflag, VOL_FLAG_CHRC_UUID);
+
+       if (!bt_uuid_cmp(&uuid, &uuid_vstate)) {
+               DBG("VCS Volume state found: handle 0x%04x", value_handle);
+
+               vcs = vcp_get_vcs(vcp);
+               if (!vcs || vcs->vs)
+                       return;
+
+               vcs->vs = attr;
+
+               vcp_read_value(vcp, value_handle, read_vol_state, vcp);
+               vcp->vstate_id = bt_gatt_client_register_notify(vcp->client,
+                                               value_handle,
+                                               vcp_vstate_register,
+                                               vcp_vstate_notify, vcp, NULL);
+
+               return;
+       }
+
+       if (!bt_uuid_cmp(&uuid, &uuid_cp)) {
+               DBG("VCS Volume CP found: handle 0x%04x", value_handle);
+
+               vcs = vcp_get_vcs(vcp);
+               if (!vcs || vcs->vol_cp)
+                       return;
+
+               vcs->vol_cp = attr;
+
+               return;
+       }
+
+       if (!bt_uuid_cmp(&uuid, &uuid_vflag)) {
+               DBG("VCS Vol Flaf found: handle 0x%04x", value_handle);
+
+               vcs = vcp_get_vcs(vcp);
+               if (!vcs || vcs->vf)
+                       return;
+
+               vcs->vf = attr;
+
+               vcp_read_value(vcp, value_handle, read_vol_flag, vcp);
+               vcp->vflag_id = bt_gatt_client_register_notify(vcp->client,
+                                               value_handle,
+                                               vcp_vflag_register,
+                                               vcp_vflag_notify, vcp, NULL);
+       }
+
+}
+
+static void foreach_vcs_service(struct gatt_db_attribute *attr,
+                                               void *user_data)
+{
+       struct bt_vcp *vcp = user_data;
+       struct bt_vcs *vcs = vcp_get_vcs(vcp);
+
+       DBG("");
+       vcs->service = attr;
+
+       gatt_db_service_set_claimed(attr, true);
+
+       gatt_db_service_foreach_char(attr, foreach_vcs_char, vcp);
+}
+
+bool bt_vcp_attach(struct bt_vcp *vcp, struct bt_gatt_client *client)
+{
+       bt_uuid_t uuid;
+
+       if (!sessions)
+               sessions = queue_new();
+
+       queue_push_tail(sessions, vcp);
+
+       if (!client)
+               return true;
+
+       if (vcp->client)
+               return false;
+
+       vcp->client = bt_gatt_client_clone(client);
+       if (!vcp->client)
+               return false;
+
+       bt_uuid16_create(&uuid, VCS_UUID);
+       gatt_db_foreach_service(vcp->ldb->db, &uuid, foreach_vcs_service, vcp);
+
+       return true;
+}
diff --git a/src/shared/vcp.h b/src/shared/vcp.h
new file mode 100644 (file)
index 0000000..1a999c7
--- /dev/null
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2020  Intel Corporation. All rights reserved.
+ *
+ */
+
+#include <stdbool.h>
+#include <inttypes.h>
+
+#include "src/shared/io.h"
+
+#define BT_VCP_RENDERER                        0x01
+#define        BT_VCP_CONTROLLER               0x02
+
+#define BT_VCP_RELATIVE_VOL_DOWN       0x00
+#define BT_VCP_RELATIVE_VOL_UP         0x01
+#define BT_VCP_UNMUTE_RELATIVE_VOL_DOWN        0x02
+#define BT_VCP_UNMUTE_RELATIVE_VOL_UP  0x03
+#define BT_VCP_SET_ABOSULTE_VOL                0x04
+#define BT_VCP_UNMUTE                  0x05
+#define BT_VCP_MUTE                    0x06
+
+#ifndef MAX
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+struct bt_vcp;
+
+typedef void (*bt_vcp_func_t)(struct bt_vcp *vcp, void *user_data);
+
+struct bt_vcp *bt_vcp_ref(struct bt_vcp *vcp);
+void bt_vcp_unref(struct bt_vcp *vcp);
+
+void bt_vcp_add_db(struct gatt_db *db);
+
+bool bt_vcp_attach(struct bt_vcp *vcp, struct bt_gatt_client *client);
+void bt_vcp_detach(struct bt_vcp *vcp);
+
+struct bt_att *bt_vcp_get_att(struct bt_vcp *vcp);
+
+bool bt_vcp_set_user_data(struct bt_vcp *vcp, void *user_data);
+
+/* Session related function */
+unsigned int bt_vcp_register(bt_vcp_func_t added, bt_vcp_func_t removed,
+                                                       void *user_data);
+bool bt_vcp_unregister(unsigned int id);
+struct bt_vcp *bt_vcp_new(struct gatt_db *ldb, struct gatt_db *rdb);