zephyr/include/bluetooth/buf.h
Johan Hedberg d67416321e Bluetooth: hci_raw: Add support for specifying buffer headroom
The HCI transport implemented by an application using the HCI raw
interface may have its own buffer headroom requirements. Currently the
available headroom gets completely determined by the selected HCI
driver. E.g. most of the time this is the native controller driver
which doesn't reserve any headroom at all.

To cover for the needs of HCI raw users, add a new Kconfig variable
for the apps to set to whatever they need. Correspondingly, use the
maximum of the HCI driver and HCI raw headroom requirements for the
buffer pool definitions and the headroom initializations.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
2019-11-20 19:29:06 +01:00

118 lines
3.2 KiB
C

/** @file
* @brief Bluetooth data buffer API
*/
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_
#define ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_
/**
* @brief Data buffers
* @defgroup bt_buf Data buffers
* @ingroup bluetooth
* @{
*/
#include <zephyr/types.h>
#include <net/buf.h>
#include <bluetooth/hci.h>
/** Possible types of buffers passed around the Bluetooth stack */
enum bt_buf_type {
/** HCI command */
BT_BUF_CMD,
/** HCI event */
BT_BUF_EVT,
/** Outgoing ACL data */
BT_BUF_ACL_OUT,
/** Incoming ACL data */
BT_BUF_ACL_IN,
};
/** Minimum amount of user data size for buffers passed to the stack. */
#define BT_BUF_USER_DATA_MIN 8
#if defined(CONFIG_BT_HCI_RAW)
#define BT_BUF_RESERVE MAX(CONFIG_BT_HCI_RESERVE, CONFIG_BT_HCI_RAW_RESERVE)
#else
#define BT_BUF_RESERVE CONFIG_BT_HCI_RESERVE
#endif
/** Data size neeed for HCI RX buffers */
#define BT_BUF_RX_SIZE (BT_BUF_RESERVE + CONFIG_BT_RX_BUF_LEN)
/** Allocate a buffer for incoming data
*
* This will set the buffer type so bt_buf_set_type() does not need to
* be explicitly called before bt_recv_prio().
*
* @param type Type of buffer. Only BT_BUF_EVT and BT_BUF_ACL_IN are
* allowed.
* @param timeout Timeout in milliseconds, or one of the special values
* K_NO_WAIT and K_FOREVER.
* @return A new buffer.
*/
struct net_buf *bt_buf_get_rx(enum bt_buf_type type, s32_t timeout);
/** Allocate a buffer for an HCI Command Complete/Status Event
*
* This will set the buffer type so bt_buf_set_type() does not need to
* be explicitly called before bt_recv_prio().
*
* @param timeout Timeout in milliseconds, or one of the special values
* K_NO_WAIT and K_FOREVER.
* @return A new buffer.
*/
struct net_buf *bt_buf_get_cmd_complete(s32_t timeout);
/** Allocate a buffer for an HCI Event
*
* This will set the buffer type so bt_buf_set_type() does not need to
* be explicitly called before bt_recv_prio() or bt_recv().
*
* @param evt HCI event code
* @param discardable Whether the driver considers the event discardable.
* @param timeout Timeout in milliseconds, or one of the special values
* K_NO_WAIT and K_FOREVER.
* @return A new buffer.
*/
struct net_buf *bt_buf_get_evt(u8_t evt, bool discardable, s32_t timeout);
/** Set the buffer type
*
* @param buf Bluetooth buffer
* @param type The BT_* type to set the buffer to
*/
static inline void bt_buf_set_type(struct net_buf *buf, enum bt_buf_type type)
{
*(u8_t *)net_buf_user_data(buf) = type;
}
/** Get the buffer type
*
* @param buf Bluetooth buffer
*
* @return The BT_* type to of the buffer
*/
static inline enum bt_buf_type bt_buf_get_type(struct net_buf *buf)
{
/* De-referencing the pointer from net_buf_user_data(buf) as a
* pointer to an enum causes issues on qemu_x86 because the true
* size is 8-bit, but the enum is 32-bit on qemu_x86. So we put in
* a temporary cast to 8-bit to ensure only 8 bits are read from
* the pointer.
*/
return (enum bt_buf_type)(*(u8_t *)net_buf_user_data(buf));
}
/**
* @}
*/
#endif /* ZEPHYR_INCLUDE_BLUETOOTH_BUF_H_ */