lib: Create API to write a GATT characteristic

2 files changed, 82 insertions, 4 deletions

diff --git a/lib/ble.c b/lib/ble.c
index 4a96e66..d407d0d 100644
--- a/lib/ble.c
+++ b/lib/ble.c
@@ -559,7 +559,22 @@ static void read_descriptor_cb(int conn_id, int status,
                               p_data->value.len, p_data->value_type, status);
 }
 
-static int ble_gatt_op(int operation, int conn_id, int id, int auth) {
+/* Called when a GATT write characteristic operation returns */
+static void write_characteristic_cb(int conn_id, int status,
+                                    btgatt_write_params_t *p_data) {
+    ble_device_t *dev;
+    int id = -1;
+
+    dev = find_device_by_conn_id(conn_id);
+    if (dev)
+        id = find_characteristic(dev, &p_data->srvc_id, &p_data->char_id);
+
+    if (data.cbs.char_write_cb)
+        data.cbs.char_write_cb(conn_id, id, NULL, 0, 0, status);
+}
+
+static int ble_gatt_op(int operation, int conn_id, int id, int auth,
+                       const char *value, int len) {
     ble_device_t *dev;
     bt_status_t s = BT_STATUS_UNSUPPORTED;
 
@@ -601,6 +616,20 @@ static int ble_gatt_op(int operation, int conn_id, int id, int auth) {
 							&dev->descs[id].d,
                                                         auth);
             break;
+
+        case 2: /* Write characteristic with write command */
+        case 3: /* Write characteristic with write request */
+        case 4: /* Write characteristic with prepare write */
+            if (dev->char_count <= 0 || id >= dev->char_count)
+                return -1;
+
+            s = data.gattiface->client->write_characteristic(conn_id,
+	                                                     &dev->chars[id].s,
+	                                                     &dev->chars[id].c,
+                                                             operation-1, len,
+                                                             auth,
+                                                             (char *) value);
+            break;
     }
 
     if (s != BT_STATUS_SUCCESS)
@@ -610,11 +639,21 @@ static int ble_gatt_op(int operation, int conn_id, int id, int auth) {
 }
 
 int ble_gatt_read_char(int conn_id, int char_id, int auth) {
-    return ble_gatt_op(0, conn_id, char_id, auth);
+    return ble_gatt_op(0, conn_id, char_id, auth, NULL, 0);
 }
 
 int ble_gatt_read_desc(int conn_id, int desc_id, int auth) {
-    return ble_gatt_op(1, conn_id, desc_id, auth);
+    return ble_gatt_op(1, conn_id, desc_id, auth, NULL, 0);
+}
+
+int ble_gatt_write_cmd_char(int conn_id, int char_id, int auth,
+                            const char *value, int len) {
+    return ble_gatt_op(2, conn_id, char_id, auth, value, len);
+}
+
+int ble_gatt_write_req_char(int conn_id, int char_id, int auth,
+                            const char *value, int len) {
+    return ble_gatt_op(3, conn_id, char_id, auth, value, len);
 }
 
 /* Called when the client registration is finished */
@@ -641,7 +680,7 @@ static const btgatt_client_callbacks_t gattccbs = {
     NULL, /* register_for_notification_cb */
     NULL, /* notify_cb */
     read_characteristic_cb,
-    NULL, /* write_characteristic_cb */
+    write_characteristic_cb,
     read_descriptor_cb,
     NULL, /* write_descriptor_cb */
     NULL, /* execute_write_cb */
diff --git a/lib/ble.h b/lib/ble.h
index 10945bb..1a40f04 100644
--- a/lib/ble.h
+++ b/lib/ble.h
@@ -164,6 +164,7 @@ typedef struct ble_cbs {
     ble_gatt_finished_cb_t desc_finished_cb;
     ble_gatt_response_cb_t char_read_cb;
     ble_gatt_response_cb_t desc_read_cb;
+    ble_gatt_response_cb_t char_write_cb;
 } ble_cbs_t;
 
 /**
@@ -340,4 +341,42 @@ int ble_gatt_read_char(int conn_id, int char_id, int auth);
  * @return -1 if failed to request characteristic read.
  */
 int ble_gatt_read_desc(int conn_id, int desc_id, int auth);
+
+/**
+ * Write the value of a characteristic using write command (no response).
+ *
+ * There should be an active connection with the device.
+ *
+ * @param conn_id The identifier of the connected remote device.
+ * @param char_id The identifier of the characteristic to be written.
+ * @param auth Whether or not link authentication should be requested before
+ *             trying to write the characteristic: 1 request, 0 do not request.
+ * @param value Pointer to the value that should be written on the
+ *              characteristic.
+ * @param len The length of the data pointed by the value parameter.
+ *
+ * @return 0 if characteristic write has been successfully requested.
+ * @return -1 if failed to request characteristic write.
+ */
+int ble_gatt_write_cmd_char(int conn_id, int char_id, int auth,
+                            const char *value, int len);
+
+/**
+ * Write the value of a characteristic using write request (with response).
+ *
+ * There should be an active connection with the device.
+ *
+ * @param conn_id The identifier of the connected remote device.
+ * @param char_id The identifier of the characteristic to be written.
+ * @param auth Whether or not link authentication should be requested before
+ *             trying to write the characteristic: 1 request, 0 do not request.
+ * @param value Pointer to the value that should be written on the
+ *              characteristic.
+ * @param len The length of the data pointed by the value parameter.
+ *
+ * @return 0 if characteristic write has been successfully requested.
+ * @return -1 if failed to request characteristic write.
+ */
+int ble_gatt_write_req_char(int conn_id, int char_id, int auth,
+                            const char *value, int len);
 #endif