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/* drivers/tty/smux_private.h
*
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#ifndef SMUX_PRIVATE_H
#define SMUX_PRIVATE_H
#define SMUX_MAX_PKT_SIZE 8192
#define SMUX_BROADCAST_LCID 0xFF
/* SMUX Protocol Characters */
#define SMUX_MAGIC 0x33FC
#define SMUX_MAGIC_WORD1 0xFC
#define SMUX_MAGIC_WORD2 0x33
#define SMUX_WAKEUP_REQ 0xFD
#define SMUX_WAKEUP_ACK 0xFE
/* Unit testing characters */
#define SMUX_UT_ECHO_REQ 0xF0
#define SMUX_UT_ECHO_ACK_OK 0xF1
#define SMUX_UT_ECHO_ACK_FAIL 0xF2
/* Maximum number of packets in retry queue */
#define SMUX_RX_RETRY_MAX_PKTS 128
#define SMUX_RX_WM_HIGH 4
#define SMUX_RX_WM_LOW 0
#define SMUX_TX_WM_LOW 2
#define SMUX_TX_WM_HIGH 4
struct tty_struct;
/**
* Logical Channel Structure. One instance per channel.
*
* Locking Hierarchy
* Each lock has a postfix that describes the locking level. If multiple locks
* are required, only increasing lock hierarchy numbers may be locked which
* ensures avoiding a deadlock.
*
* Locking Example
* If state_lock_lhb1 is currently held and the TX list needs to be
* manipulated, then tx_lock_lhb2 may be locked since it's locking hierarchy
* is greater. However, if tx_lock_lhb2 is held, then state_lock_lhb1 may
* not be acquired since it would result in a deadlock.
*
* Note that the Line Discipline locks (*_lha) should always be acquired
* before the logical channel locks.
*/
struct smux_lch_t {
/* channel state */
spinlock_t state_lock_lhb1;
uint8_t lcid;
unsigned local_state;
unsigned local_mode;
uint8_t local_tiocm;
unsigned options;
unsigned remote_state;
unsigned remote_mode;
uint8_t remote_tiocm;
int tx_flow_control;
int rx_flow_control_auto;
int rx_flow_control_client;
/* client callbacks and private data */
void *priv;
void (*notify)(void *priv, int event_type, const void *metadata);
int (*get_rx_buffer)(void *priv, void **pkt_priv, void **buffer,
int size);
/* RX Info */
struct list_head rx_retry_queue;
unsigned rx_retry_queue_cnt;
struct delayed_work rx_retry_work;
/* TX Info */
spinlock_t tx_lock_lhb2;
struct list_head tx_queue;
struct list_head tx_ready_list;
unsigned tx_pending_data_cnt;
unsigned notify_lwm;
};
/* Each instance of smux_lch_t */
extern struct smux_lch_t smux_lch[SMUX_NUM_LOGICAL_CHANNELS];
/* Packet header. */
struct smux_hdr_t {
uint16_t magic;
uint8_t flags;
uint8_t cmd;
uint8_t pad_len;
uint8_t lcid;
uint16_t payload_len;
};
/* Internal packet structure. */
struct smux_pkt_t {
struct smux_hdr_t hdr;
int allocated;
unsigned char *payload;
int free_payload;
struct list_head list;
void *priv;
};
/* SMUX Packet Commands */
enum {
SMUX_CMD_DATA = 0x0,
SMUX_CMD_OPEN_LCH = 0x1,
SMUX_CMD_CLOSE_LCH = 0x2,
SMUX_CMD_STATUS = 0x3,
SMUX_CMD_PWR_CTL = 0x4,
SMUX_CMD_DELAY = 0x5,
SMUX_CMD_BYTE, /* for internal usage */
SMUX_NUM_COMMANDS
};
/* Open command flags */
enum {
SMUX_CMD_OPEN_ACK = 1 << 0,
SMUX_CMD_OPEN_POWER_COLLAPSE = 1 << 1,
SMUX_CMD_OPEN_REMOTE_LOOPBACK = 1 << 2,
};
/* Close command flags */
enum {
SMUX_CMD_CLOSE_ACK = 1 << 0,
};
/* Power command flags */
enum {
SMUX_CMD_PWR_CTL_ACK = 1 << 0,
};
/* Local logical channel states */
enum {
SMUX_LCH_LOCAL_CLOSED,
SMUX_LCH_LOCAL_OPENING,
SMUX_LCH_LOCAL_OPENED,
SMUX_LCH_LOCAL_CLOSING,
};
/* Remote logical channel states */
enum {
SMUX_LCH_REMOTE_CLOSED,
SMUX_LCH_REMOTE_OPENED,
};
/* Enum used to report various undefined actions */
enum {
SMUX_UNDEF_LONG,
SMUX_UNDEF_SHORT,
};
long msm_smux_tiocm_get_atomic(struct smux_lch_t *ch);
const char *local_lch_state(unsigned state);
const char *remote_lch_state(unsigned state);
const char *lch_mode(unsigned mode);
int smux_assert_lch_id(uint32_t lcid);
void smux_init_pkt(struct smux_pkt_t *pkt);
struct smux_pkt_t *smux_alloc_pkt(void);
int smux_alloc_pkt_payload(struct smux_pkt_t *pkt);
void smux_free_pkt(struct smux_pkt_t *pkt);
int smux_serialize(struct smux_pkt_t *pkt, char *out,
unsigned int *out_len);
void smux_rx_state_machine(const unsigned char *data, int len, int flag);
void smuxld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
char *fp, int count);
bool smux_remote_is_active(void);
void smux_set_loopback_data_reply_delay(uint32_t ms);
void smux_get_wakeup_counts(int *local_cnt, int *remote_cnt);
/* testing parameters */
extern int smux_byte_loopback;
extern int smux_simulate_wakeup_delay;
#endif /* SMUX_PRIVATE_H */
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