1  /** @file
2   *  @brief Bluetooth data buffer API
3   */
4  
5  /*
6   * Copyright (c) 2016 Intel Corporation
7   *
8   * SPDX-License-Identifier: Apache-2.0
9   */
10  
11  #ifndef ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_
12  #define ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_
13  
14  /**
15   * @brief Data buffers
16   * @defgroup bt_buf Data buffers
17   * @ingroup bluetooth
18   * @{
19   */
20  
21  #include <ble_types/types.h>
22  #include <net/buf.h>
23  #include <bluetooth/hci.h>
24  
25  /** Possible types of buffers passed around the Bluetooth stack */
26  enum bt_buf_type {
27  	/** HCI command */
28  	BT_BUF_CMD,
29  	/** HCI event */
30  	BT_BUF_EVT,
31  	/** Outgoing ACL data */
32  	BT_BUF_ACL_OUT,
33  	/** Incoming ACL data */
34  	BT_BUF_ACL_IN,
35  	/** H:4 data */
36  	BT_BUF_H4,
37  };
38  
39  /** Minimum amount of user data size for buffers passed to the stack. */
40  #define BT_BUF_USER_DATA_MIN 4 // __DEPRECATED_MACRO
41  
42  #if defined(CONFIG_BT_HCI_RAW)
43  #define BT_BUF_RESERVE MAX(CONFIG_BT_HCI_RESERVE, CONFIG_BT_HCI_RAW_RESERVE)
44  #else
45  #define BT_BUF_RESERVE CONFIG_BT_HCI_RESERVE
46  #endif
47  
48  #define BT_BUF_SIZE(size) (BT_BUF_RESERVE + (size))
49  
50  /** Data size neeed for HCI RX buffers */
51  #define BT_BUF_RX_SIZE (BT_BUF_SIZE(CONFIG_BT_RX_BUF_LEN))
52  
53  /** Allocate a buffer for incoming data
54   *
55   *  This will set the buffer type so bt_buf_set_type() does not need to
56   *  be explicitly called before bt_recv_prio().
57   *
58   *  @param type    Type of buffer. Only BT_BUF_EVT and BT_BUF_ACL_IN are
59   *                 allowed.
60   *  @param timeout Non-negative waiting period to obtain a buffer or one of the
61   *                 special values K_NO_WAIT and K_FOREVER.
62   *  @return A new buffer.
63   */
64  struct net_buf *bt_buf_get_rx(enum bt_buf_type type, k_timeout_t timeout);
65  
66  /** Allocate a buffer for outgoing data
67   *
68   *  This will set the buffer type so bt_buf_set_type() does not need to
69   *  be explicitly called before bt_send().
70   *
71   *  @param type    Type of buffer. Only BT_BUF_CMD, BT_BUF_ACL_OUT or
72   *                 BT_BUF_H4, when operating on H:4 mode, are allowed.
73   *  @param timeout Non-negative waiting period to obtain a buffer or one of the
74   *                 special values K_NO_WAIT and K_FOREVER.
75   *  @param data    Initial data to append to buffer.
76   *  @param size    Initial data size.
77   *  @return A new buffer.
78   */
79  struct net_buf *bt_buf_get_tx(enum bt_buf_type type, k_timeout_t timeout,
80  			      const void *data, size_t size);
81  
82  /** Allocate a buffer for an HCI Command Complete/Status Event
83   *
84   *  This will set the buffer type so bt_buf_set_type() does not need to
85   *  be explicitly called before bt_recv_prio().
86   *
87   *  @param timeout Non-negative waiting period to obtain a buffer or one of the
88   *                 special values K_NO_WAIT and K_FOREVER.
89   *  @return A new buffer.
90   */
91  struct net_buf *bt_buf_get_cmd_complete(k_timeout_t timeout);
92  
93  /** Allocate a buffer for an HCI Event
94   *
95   *  This will set the buffer type so bt_buf_set_type() does not need to
96   *  be explicitly called before bt_recv_prio() or bt_recv().
97   *
98   *  @param evt          HCI event code
99   *  @param discardable  Whether the driver considers the event discardable.
100   *  @param timeout      Non-negative waiting period to obtain a buffer or one of
101   *                      the special values K_NO_WAIT and K_FOREVER.
102   *  @return A new buffer.
103   */
104  struct net_buf *bt_buf_get_evt(u8_t evt, bool discardable, k_timeout_t timeout);
105  
106  /** Set the buffer type
107   *
108   *  @param buf   Bluetooth buffer
109   *  @param type  The BT_* type to set the buffer to
110   */
bt_buf_set_type(struct net_buf * buf,enum bt_buf_type type)111  static inline void bt_buf_set_type(struct net_buf *buf, enum bt_buf_type type)
112  {
113  	*(u8_t *)net_buf_user_data(buf) = type;
114  }
115  
116  /** Get the buffer type
117   *
118   *  @param buf   Bluetooth buffer
119   *
120   *  @return The BT_* type to of the buffer
121   */
bt_buf_get_type(struct net_buf * buf)122  static inline enum bt_buf_type bt_buf_get_type(struct net_buf *buf)
123  {
124  	/* De-referencing the pointer from net_buf_user_data(buf) as a
125  	 * pointer to an enum causes issues on qemu_x86 because the true
126  	 * size is 8-bit, but the enum is 32-bit on qemu_x86. So we put in
127  	 * a temporary cast to 8-bit to ensure only 8 bits are read from
128  	 * the pointer.
129  	 */
130  	return (enum bt_buf_type)(*(u8_t *)net_buf_user_data(buf));
131  }
132  
133  /**
134   * @}
135   */
136  
137  #endif /* ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_ */
138