Serial communications layer, based on HDLC. More...

Files
file	sercomm.h
	Osmocom Sercomm HDLC (de)multiplex.

file	sercomm.c

Data Structures
struct	osmo_sercomm_inst
	one instance of a sercomm multiplex/demultiplex More...

Macros
#define	DEFAULT_RX_MSG_SIZE 2048

#define	HDLC_FLAG 0x7E

#define	HDLC_ESCAPE 0x7D

#define	HDLC_C_UI 0x03

#define	HDLC_C_P_BIT (1 << 4)

#define	HDLC_C_F_BIT (1 << 4)

Typedefs
typedef void(*	dlci_cb_t) (struct osmo_sercomm_inst sercomm, uint8_t dlci, struct msgb msg)
	call-back function for per-DLC receive handler More...

Enumerations
enum	sercomm_dlci { SC_DLCI_HIGHEST = 0 , SC_DLCI_DEBUG = 4 , SC_DLCI_L1A_L23 = 5 , SC_DLCI_LOADER = 9 , SC_DLCI_CONSOLE = 10 , SC_DLCI_ECHO = 128 , _SC_DLCI_MAX }
	A low sercomm_dlci means high priority. More...

enum	rx_state { RX_ST_WAIT_START , RX_ST_ADDR , RX_ST_CTRL , RX_ST_DATA , RX_ST_ESCAPE }

Functions
void	osmo_sercomm_init (struct osmo_sercomm_inst *sercomm)
	Initialize an Osmocom sercomm instance. More...

int	osmo_sercomm_initialized (struct osmo_sercomm_inst *sercomm)
	Determine if a given Osmocom sercomm instance has been initialized. More...

void	osmo_sercomm_sendmsg (struct osmo_sercomm_inst sercomm, uint8_t dlci, struct msgb msg)
	User interface for transmitting messages for a given DLCI. More...

unsigned int	osmo_sercomm_tx_queue_depth (struct osmo_sercomm_inst *sercomm, uint8_t dlci)
	How deep is the Tx queue for a given DLCI? More...

int	osmo_sercomm_register_rx_cb (struct osmo_sercomm_inst *sercomm, uint8_t dlci, dlci_cb_t cb)
	Register a handler for a given DLCI. More...

int	osmo_sercomm_change_speed (struct osmo_sercomm_inst *sercomm, uint32_t bdrt)
	wait until everything has been transmitted, then grab the lock and change the baud rate as requested More...

int	osmo_sercomm_drv_pull (struct osmo_sercomm_inst sercomm, uint8_t ch)
	fetch one octet of to-be-transmitted serial data More...

int	osmo_sercomm_drv_rx_char (struct osmo_sercomm_inst *sercomm, uint8_t ch)
	the driver has received one byte, pass it into sercomm layer More...

void	sercomm_drv_lock (unsigned long *flags)

void	sercomm_drv_unlock (unsigned long *flags)

void	sercomm_drv_start_tx (struct osmo_sercomm_inst *sercomm)
	low-level driver routine to request start of transmission The Sercomm code calls this function to inform the low-level driver that some data is pending for transmission, and the low-level driver should (if not active already) start enabling tx_empty interrupts and pull drivers out of sercomm using osmo_sercomm_drv_pull() until the latter returns 0. More...

int	sercomm_drv_baudrate_chg (struct osmo_sercomm_inst *sercomm, uint32_t bdrt)
	low-level driver routine to execute baud-rate change More...

static struct msgb *	osmo_sercomm_alloc_msgb (unsigned int len)
	Sercomm msgb allocator function. More...

void	sercomm_drv_lock (unsigned long __attribute__((unused)) *flags)
	Protect against IRQ context. More...

void	sercomm_drv_unlock (unsigned long __attribute__((unused)) *flags)
	Release protection against IRQ context. More...

	__attribute__ ((weak))

static void	dispatch_rx_msg (struct osmo_sercomm_inst sercomm, uint8_t dlci, struct msgb msg)

Variables
enum gsm0808_assignment_requirement	__attribute__
	fls64 - find last set bit in a 64-bit word @x: the word to search More...

Detailed Description

Serial communications layer, based on HDLC.

Macro Definition Documentation

◆ DEFAULT_RX_MSG_SIZE

#define DEFAULT_RX_MSG_SIZE 2048

◆ HDLC_C_F_BIT

#define HDLC_C_F_BIT (1 << 4)

◆ HDLC_C_P_BIT

#define HDLC_C_P_BIT (1 << 4)

◆ HDLC_C_UI

#define HDLC_C_UI 0x03

◆ HDLC_ESCAPE

#define HDLC_ESCAPE 0x7D

◆ HDLC_FLAG

#define HDLC_FLAG 0x7E

Typedef Documentation

◆ dlci_cb_t

typedef void(* dlci_cb_t) (struct osmo_sercomm_inst *sercomm, uint8_t dlci, struct msgb *msg)

call-back function for per-DLC receive handler

Parameters

[in]	sercomm	instance on which msg was received
[in]	dlci	DLC Identifier of received msg
[in]	msg	received message that needs to be processed

Enumeration Type Documentation

◆ rx_state

enum rx_state

Enumerator
RX_ST_WAIT_START
RX_ST_ADDR
RX_ST_CTRL
RX_ST_DATA
RX_ST_ESCAPE

◆ sercomm_dlci

enum sercomm_dlci

A low sercomm_dlci means high priority.

A high DLCI means low priority

Enumerator
SC_DLCI_HIGHEST
SC_DLCI_DEBUG
SC_DLCI_L1A_L23
SC_DLCI_LOADER
SC_DLCI_CONSOLE
SC_DLCI_ECHO
_SC_DLCI_MAX

Function Documentation

◆ attribute()

__attribute__ ( (weak) )

◆ dispatch_rx_msg()

static void dispatch_rx_msg	(	struct osmo_sercomm_inst *	sercomm,
		uint8_t	dlci,
		struct msgb *	msg
	)

static

References ARRAY_SIZE, osmo_sercomm_inst::dlci_handler, msg, msgb_free(), and osmo_sercomm_inst::rx.

Referenced by osmo_sercomm_drv_rx_char().

◆ osmo_sercomm_alloc_msgb()

static struct msgb * osmo_sercomm_alloc_msgb ( unsigned int len )

inlinestatic

Sercomm msgb allocator function.

References len(), and msgb_alloc_headroom().

Referenced by osmo_sercomm_drv_rx_char().

◆ osmo_sercomm_change_speed()

int osmo_sercomm_change_speed	(	struct osmo_sercomm_inst *	sercomm,
		uint32_t	bdrt
	)

wait until everything has been transmitted, then grab the lock and change the baud rate as requested

Parameters

[in]	sercomm	Osmocom sercomm instance
[in]	bdrt	New UART Baud Rate

Returns: result of the operation as provided by sercomm_drv_baudrate_chg()

References ARRAY_SIZE, osmo_sercomm_inst::dlci_queues, flags, osmo_sercomm_inst::msg, osmo_sercomm_inst::next_char, osmo_sercomm_tx_queue_depth(), sercomm_drv_baudrate_chg(), sercomm_drv_lock(), sercomm_drv_unlock(), and osmo_sercomm_inst::tx.

◆ osmo_sercomm_drv_pull()

int osmo_sercomm_drv_pull	(	struct osmo_sercomm_inst *	sercomm,
		uint8_t *	ch
	)

fetch one octet of to-be-transmitted serial data

Parameters

[in]	sercomm	Sercomm Instance from which to fetch pending data
[out]	ch	pointer to caller-allocaed output memory

Returns: 1 in case of succss; 0 if no data available; negative on error

References ARRAY_SIZE, msgb::data, osmo_sercomm_inst::dlci_queues, flags, HDLC_ESCAPE, HDLC_FLAG, osmo_sercomm_inst::msg, msgb_dequeue(), msgb_free(), osmo_sercomm_inst::next_char, RX_ST_DATA, RX_ST_ESCAPE, sercomm_drv_lock(), sercomm_drv_unlock(), osmo_sercomm_inst::state, msgb::tail, and osmo_sercomm_inst::tx.

◆ osmo_sercomm_drv_rx_char()

int osmo_sercomm_drv_rx_char	(	struct osmo_sercomm_inst *	sercomm,
		uint8_t	ch
	)

the driver has received one byte, pass it into sercomm layer

Parameters

[in]	sercomm	Sercomm Instance for which a byte was received
[in]	ch	byte that was received from line for said instance

Returns: 1 on success; 0 on unrecognized char; negative on error

References osmo_sercomm_inst::ctrl, dispatch_rx_msg(), osmo_sercomm_inst::dlci, HDLC_ESCAPE, HDLC_FLAG, osmo_sercomm_inst::msg, osmo_sercomm_inst::msg_size, msgb_free(), msgb_put(), msgb_tailroom(), osmo_sercomm_alloc_msgb(), osmo_sercomm_inst::rx, RX_ST_ADDR, RX_ST_CTRL, RX_ST_DATA, RX_ST_ESCAPE, RX_ST_WAIT_START, and osmo_sercomm_inst::state.

◆ osmo_sercomm_init()

void osmo_sercomm_init ( struct osmo_sercomm_inst * sercomm )

Initialize an Osmocom sercomm instance.

Parameters

sercomm Caller-allocated sercomm instance to be initialized

This function initializes the sercomm instance, including the registration of the ECHO service at the ECHO DLCI

References ARRAY_SIZE, DEFAULT_RX_MSG_SIZE, osmo_sercomm_inst::dlci_queues, INIT_LLIST_HEAD, osmo_sercomm_inst::initialized, osmo_sercomm_inst::msg, osmo_sercomm_inst::msg_size, osmo_sercomm_register_rx_cb(), osmo_sercomm_sendmsg(), osmo_sercomm_inst::rx, SC_DLCI_ECHO, and osmo_sercomm_inst::tx.

◆ osmo_sercomm_initialized()

int osmo_sercomm_initialized ( struct osmo_sercomm_inst * sercomm )

Determine if a given Osmocom sercomm instance has been initialized.

Parameters

[in] sercomm Osmocom sercomm instance to be checked

Returns: 1 in case sercomm was previously initialized; 0 otherwise

References osmo_sercomm_inst::initialized.

◆ osmo_sercomm_register_rx_cb()

int osmo_sercomm_register_rx_cb	(	struct osmo_sercomm_inst *	sercomm,
		uint8_t	dlci,
		dlci_cb_t	cb
	)

Register a handler for a given DLCI.

Parameters

	sercomm	Sercomm Instance in which caller wishes to register
[in]	dlci	Data Ling Connection Identifier to register
[in]	cb	Callback function for dlci

Returns: 0 on success; negative on error

References ARRAY_SIZE, osmo_sercomm_inst::dlci_handler, and osmo_sercomm_inst::rx.

Referenced by osmo_sercomm_init().

◆ osmo_sercomm_sendmsg()

void osmo_sercomm_sendmsg	(	struct osmo_sercomm_inst *	sercomm,
		uint8_t	dlci,
		struct msgb *	msg
	)

User interface for transmitting messages for a given DLCI.

Parameters

[in]	sercomm	Osmocom sercomm instance through which to transmit
[in]	dlci	DLCI through whcih to transmit msg
[in]	msg	Message buffer to be transmitted via dlci on * sercomm

References osmo_sercomm_inst::dlci_queues, flags, HDLC_C_UI, hdr, msg, msgb_enqueue(), msgb_push(), sercomm_drv_lock(), sercomm_drv_start_tx(), sercomm_drv_unlock(), and osmo_sercomm_inst::tx.

Referenced by osmo_sercomm_init().

◆ osmo_sercomm_tx_queue_depth()

unsigned int osmo_sercomm_tx_queue_depth	(	struct osmo_sercomm_inst *	sercomm,
		uint8_t	dlci
	)

How deep is the Tx queue for a given DLCI?

Parameters

	[n]	sercomm Osmocom sercomm instance on which to operate
[in]	dlci	DLCI whose queue depthy is to be determined

Returns: number of elements in the per-DLCI transmit queue

References osmo_sercomm_inst::dlci_queues, llist_for_each, and osmo_sercomm_inst::tx.

Referenced by osmo_sercomm_change_speed().

◆ sercomm_drv_baudrate_chg()

int sercomm_drv_baudrate_chg	(	struct osmo_sercomm_inst *	sercomm,
		uint32_t	bdrt
	)

low-level driver routine to execute baud-rate change

Parameters

[in]	sercomm	Osmocom sercomm instance for which to change
[in]	bdrt	New Baud-Rate (integer)

Returns: 0 on success; negative in case of error

Referenced by osmo_sercomm_change_speed().

◆ sercomm_drv_lock() [1/2]

void sercomm_drv_lock ( unsigned long * flags )

◆ sercomm_drv_lock() [2/2]

void sercomm_drv_lock ( unsigned long __attribute__((unused)) * flags )

Protect against IRQ context.

Referenced by osmo_sercomm_change_speed(), osmo_sercomm_drv_pull(), and osmo_sercomm_sendmsg().

◆ sercomm_drv_start_tx()

void sercomm_drv_start_tx ( struct osmo_sercomm_inst * sercomm )

low-level driver routine to request start of transmission The Sercomm code calls this function to inform the low-level driver that some data is pending for transmission, and the low-level driver should (if not active already) start enabling tx_empty interrupts and pull drivers out of sercomm using osmo_sercomm_drv_pull() until the latter returns 0.

Parameters

[in] sercomm Osmocom sercomm instance for which to change

Referenced by osmo_sercomm_sendmsg().

◆ sercomm_drv_unlock() [1/2]

void sercomm_drv_unlock ( unsigned long * flags )

◆ sercomm_drv_unlock() [2/2]

void sercomm_drv_unlock ( unsigned long __attribute__((unused)) * flags )

Release protection against IRQ context.

Referenced by osmo_sercomm_change_speed(), osmo_sercomm_drv_pull(), and osmo_sercomm_sendmsg().

Files

Data Structures

Macros

Typedefs

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ DEFAULT_RX_MSG_SIZE

◆ HDLC_C_F_BIT

◆ HDLC_C_P_BIT

◆ HDLC_C_UI

◆ HDLC_ESCAPE

◆ HDLC_FLAG

Typedef Documentation

◆ dlci_cb_t

Enumeration Type Documentation

◆ rx_state

◆ sercomm_dlci

Function Documentation

◆ __attribute__()

◆ dispatch_rx_msg()

◆ osmo_sercomm_alloc_msgb()

◆ osmo_sercomm_change_speed()

◆ osmo_sercomm_drv_pull()

◆ osmo_sercomm_drv_rx_char()

◆ osmo_sercomm_init()

◆ osmo_sercomm_initialized()

◆ osmo_sercomm_register_rx_cb()

◆ osmo_sercomm_sendmsg()

◆ osmo_sercomm_tx_queue_depth()

◆ sercomm_drv_baudrate_chg()

◆ sercomm_drv_lock() [1/2]

◆ sercomm_drv_lock() [2/2]

◆ sercomm_drv_start_tx()

◆ sercomm_drv_unlock() [1/2]

◆ sercomm_drv_unlock() [2/2]

◆ attribute()