soft_uart.c File Reference

Software UART implementation. More...

#include <stdbool.h>
#include <stdint.h>
#include <errno.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/timer.h>
#include <osmocom/core/soft_uart.h>

Data Structures
struct	osmo_soft_uart
	Internal state of a soft-UART. More...

Enumerations
enum	suart_flow_state {   SUART_FLOW_ST_IDLE ,   SUART_FLOW_ST_DATA ,   SUART_FLOW_ST_PARITY ,   SUART_FLOW_ST_STOP }
	Rx/Tx flow state of a soft-UART. More...

Functions
void	osmo_soft_uart_flush_rx (struct osmo_soft_uart *suart)
	Flush the receive buffer, passing ownership of the msgb to the .rx_cb(). More...
static void	suart_rx_ch (struct osmo_soft_uart *suart, uint8_t ch)
static void	suart_rx_bit (struct osmo_soft_uart *suart, const ubit_t bit)
static void	suart_rx_timer_cb (void *data)
int	osmo_soft_uart_rx_ubits (struct osmo_soft_uart *suart, const ubit_t *ubits, size_t n_ubits)
	Feed a number of unpacked bits into the soft-UART receiver. More...
static ubit_t	suart_tx_bit (struct osmo_soft_uart *suart, struct msgb *msg)
static size_t	suart_tx_pending (struct osmo_soft_uart *suart, ubit_t *ubits, size_t n_ubits)
int	osmo_soft_uart_tx_ubits (struct osmo_soft_uart *suart, ubit_t *ubits, size_t n_ubits)
	Pull a number of unpacked bits out of the soft-UART transmitter. More...
unsigned int	osmo_soft_uart_get_status (const struct osmo_soft_uart *suart)
	Get the modem status bitmask of the given soft-UART. More...
int	osmo_soft_uart_set_status (struct osmo_soft_uart *suart, unsigned int status)
	Set the modem status bitmask of the given soft-UART. More...
void	osmo_soft_uart_set_status_line (struct osmo_soft_uart *suart, enum osmo_soft_uart_status line, bool active)
	Activate/deactivate a modem status line of the given soft-UART. More...
struct osmo_soft_uart *	osmo_soft_uart_alloc (void *ctx, const char *name, const struct osmo_soft_uart_cfg *cfg)
	Allocate a soft-UART instance. More...
void	osmo_soft_uart_free (struct osmo_soft_uart *suart)
	Release memory taken by the given soft-UART. More...
int	osmo_soft_uart_configure (struct osmo_soft_uart *suart, const struct osmo_soft_uart_cfg *cfg)
	Change soft-UART configuration to the user-provided config. More...
const char *	osmo_soft_uart_get_name (const struct osmo_soft_uart *suart)
	Get a name for the given soft-UART instance. More...
void	osmo_soft_uart_set_name (struct osmo_soft_uart *suart, const char *name)
	Set a new name for the given soft-UART instance. More...
int	osmo_soft_uart_set_rx (struct osmo_soft_uart *suart, bool enable)
	Enable/disable receiver of the given soft-UART. More...
int	osmo_soft_uart_set_tx (struct osmo_soft_uart *suart, bool enable)
	Enable/disable transmitter of the given soft-UART. More...

Variables
const struct osmo_soft_uart_cfg	osmo_soft_uart_default_cfg
	Default soft-UART configuration (8-N-1) More...

Detailed Description

Software UART implementation.

Enumeration Type Documentation

suart_flow_state

enum suart_flow_state

Rx/Tx flow state of a soft-UART.

Enumerator
SUART_FLOW_ST_IDLE	waiting for a start bit or Tx data
SUART_FLOW_ST_DATA	receiving/transmitting data bits
SUART_FLOW_ST_PARITY	receiving/transmitting parity bits
SUART_FLOW_ST_STOP	receiving/transmitting stop bits

Function Documentation

osmo_soft_uart_alloc()

struct osmo_soft_uart * osmo_soft_uart_alloc	(	void *	ctx,
		const char *	name,
		const struct osmo_soft_uart_cfg *	cfg
	)

Allocate a soft-UART instance.

Parameters

[in]	ctx	parent talloc context.
[in]	name	name of the soft-UART instance.
[in]	cfg	initial configuration of the soft-UART instance.

Returns

pointer to allocated soft-UART instance; NULL on error.

References osmo_soft_uart::cfg, name, osmo_soft_uart::name, and OSMO_ASSERT.

osmo_soft_uart_configure()

int osmo_soft_uart_configure	(	struct osmo_soft_uart *	suart,
		const struct osmo_soft_uart_cfg *	cfg
	)

Change soft-UART configuration to the user-provided config.

Parameters

[in]	suart	soft-UART instance to be re-configured.
[in]	cfg	the user-provided config to be applied.

Returns

0 on success; negative on error.

References _OSMO_SUART_PARITY_NUM, osmo_soft_uart::cfg, osmo_soft_uart_cfg::num_data_bits, osmo_soft_uart_cfg::num_stop_bits, osmo_soft_uart_flush_rx(), osmo_timer_setup(), osmo_soft_uart_cfg::parity_mode, osmo_soft_uart::rx, osmo_soft_uart_cfg::rx_buf_size, osmo_soft_uart_cfg::rx_timeout_ms, suart_rx_timer_cb(), and osmo_soft_uart::timer.

osmo_soft_uart_flush_rx()

void osmo_soft_uart_flush_rx

(

struct osmo_soft_uart *

suart

)

Flush the receive buffer, passing ownership of the msgb to the .rx_cb().

Parameters

[in]

suart

soft-UART instance holding the receive buffer.

References osmo_soft_uart::cfg, osmo_soft_uart::flags, osmo_soft_uart::msg, msgb_alloc_c(), msgb_length(), msgb_reset(), osmo_timer_del(), osmo_soft_uart_cfg::priv, osmo_soft_uart::rx, osmo_soft_uart_cfg::rx_buf_size, osmo_soft_uart_cfg::rx_cb, and osmo_soft_uart::timer.

Referenced by osmo_soft_uart_configure(), osmo_soft_uart_set_rx(), suart_rx_ch(), and suart_rx_timer_cb().

osmo_soft_uart_free()

void osmo_soft_uart_free

(

struct osmo_soft_uart *

suart

)

Release memory taken by the given soft-UART.

Parameters

[in]

suart

soft-UART instance to be free()d.

References osmo_soft_uart::msg, msgb_free(), osmo_soft_uart::name, osmo_timer_del(), osmo_soft_uart::rx, and osmo_soft_uart::timer.

osmo_soft_uart_get_name()

const char * osmo_soft_uart_get_name

(

const struct osmo_soft_uart *

suart

)

Get a name for the given soft-UART instance.

Parameters

[in]

suart

soft-UART instance to get the name from.

Returns

name of the given soft-UART instance.

References osmo_soft_uart::name.

osmo_soft_uart_get_status()

unsigned int osmo_soft_uart_get_status

(

const struct osmo_soft_uart *

suart

)

Get the modem status bitmask of the given soft-UART.

Parameters

[in]

suart

soft-UART instance to get the modem status.

Returns

bitmask of OSMO_SUART_STATUS_F_*.

References osmo_soft_uart::status.

osmo_soft_uart_rx_ubits()

int osmo_soft_uart_rx_ubits	(	struct osmo_soft_uart *	suart,
		const ubit_t *	ubits,
		size_t	n_ubits
	)

Feed a number of unpacked bits into the soft-UART receiver.

Parameters

[in]	suart	soft-UART instance to feed bits into.
[in]	ubits	pointer to the unpacked bits.
[in]	n_ubits	number of unpacked bits to be fed.

Returns

0 on success; negative on error. -EAGAIN indicates that the receiver is disabled.

References osmo_soft_uart::running, osmo_soft_uart::rx, and suart_rx_bit().

osmo_soft_uart_set_name()

void osmo_soft_uart_set_name	(	struct osmo_soft_uart *	suart,
		const char *	name
	)

Set a new name for the given soft-UART instance.

Parameters

[in]	suart	soft-UART instance to set the name for.
[in]	name	the new name.

References name, osmo_soft_uart::name, and osmo_talloc_replace_string().

osmo_soft_uart_set_rx()

int osmo_soft_uart_set_rx	(	struct osmo_soft_uart *	suart,
		bool	enable
	)

Enable/disable receiver of the given soft-UART.

Parameters

[in]	suart	soft-UART instance to be re-configured.
[in]	enable	enable/disable state of the receiver.

Returns

0 on success; negative on error.

References osmo_soft_uart::cfg, osmo_soft_uart::flow_state, osmo_soft_uart::msg, msgb_alloc_c(), osmo_soft_uart_flush_rx(), osmo_soft_uart::running, osmo_soft_uart::rx, osmo_soft_uart_cfg::rx_buf_size, and SUART_FLOW_ST_IDLE.

osmo_soft_uart_set_status()

int osmo_soft_uart_set_status	(	struct osmo_soft_uart *	suart,
		unsigned int	status
	)

Set the modem status bitmask of the given soft-UART.

Parameters

[in]	suart	soft-UART instance to set the modem status.
[in]	status	bitmask of OSMO_SUART_STATUS_F_*.

Returns

0 on success; negative on error.

References osmo_soft_uart::cfg, osmo_soft_uart_cfg::priv, osmo_soft_uart::status, and osmo_soft_uart_cfg::status_change_cb.

Referenced by osmo_soft_uart_set_status_line().

osmo_soft_uart_set_status_line()

void osmo_soft_uart_set_status_line	(	struct osmo_soft_uart *	suart,
		enum osmo_soft_uart_status	line,
		bool	active
	)

Activate/deactivate a modem status line of the given soft-UART.

Parameters

[in]	suart	soft-UART instance to update the modem status.
[in]	line	a modem status line, one of OSMO_SUART_STATUS_F_*.
[in]	active	activate (true) or deactivate (false) the line.

References osmo_soft_uart_set_status(), and osmo_soft_uart::status.

osmo_soft_uart_set_tx()

int osmo_soft_uart_set_tx	(	struct osmo_soft_uart *	suart,
		bool	enable
	)

Enable/disable transmitter of the given soft-UART.

Parameters

[in]	suart	soft-UART instance to be re-configured.
[in]	enable	enable/disable state of the transmitter.

Returns

0 on success; negative on error.

References osmo_soft_uart::flow_state, osmo_soft_uart::running, SUART_FLOW_ST_IDLE, and osmo_soft_uart::tx.

osmo_soft_uart_tx_ubits()

int osmo_soft_uart_tx_ubits	(	struct osmo_soft_uart *	suart,
		ubit_t *	ubits,
		size_t	n_ubits
	)

Pull a number of unpacked bits out of the soft-UART transmitter.

Parameters

[in]	suart	soft-UART instance to pull the bits from.
[out]	ubits	pointer to a buffer where to store pulled bits.
[in]	n_ubits	number of unpacked bits to be pulled.

Returns

number of bits pulled (may be less than n_ubits); negative on error. -EAGAIN indicates that the transmitter is disabled.

References osmo_soft_uart::cfg, osmo_soft_uart_cfg::flow_ctrl_mode, osmo_soft_uart::flow_state, msg, msgb_alloc_c(), msgb_free(), osmo_soft_uart_cfg::num_data_bits, osmo_soft_uart_cfg::num_stop_bits, OSMO_ASSERT, OSMO_SUART_FLOW_CTRL_DTR_DSR, OSMO_SUART_FLOW_CTRL_NONE, OSMO_SUART_FLOW_CTRL_RTS_CTS, OSMO_SUART_PARITY_NONE, OSMO_SUART_STATUS_F_CTS, OSMO_SUART_STATUS_F_DSR, OSMO_UNLIKELY, osmo_soft_uart_cfg::parity_mode, osmo_soft_uart_cfg::priv, osmo_soft_uart::running, osmo_soft_uart::status, SUART_FLOW_ST_IDLE, suart_tx_bit(), suart_tx_pending(), osmo_soft_uart::tx, and osmo_soft_uart_cfg::tx_cb.

suart_rx_bit()

static void suart_rx_bit ( struct osmo_soft_uart *  suart, const ubit_t  bit  )

inlinestatic

References osmo_soft_uart::bit_count, osmo_soft_uart::cfg, osmo_soft_uart::flags, osmo_soft_uart::flow_state, osmo_soft_uart_cfg::num_data_bits, osmo_soft_uart_cfg::num_stop_bits, OSMO_ASSERT, OSMO_SUART_F_FRAMING_ERROR, OSMO_SUART_F_PARITY_ERROR, OSMO_SUART_PARITY_EVEN, OSMO_SUART_PARITY_MARK, OSMO_SUART_PARITY_NONE, OSMO_SUART_PARITY_ODD, OSMO_SUART_PARITY_SPACE, osmo_soft_uart::parity_bit, osmo_soft_uart_cfg::parity_mode, osmo_soft_uart::rx, osmo_soft_uart::shift_reg, SUART_FLOW_ST_DATA, SUART_FLOW_ST_IDLE, SUART_FLOW_ST_PARITY, SUART_FLOW_ST_STOP, and suart_rx_ch().

Referenced by osmo_soft_uart_rx_ubits().

suart_rx_ch()

static void suart_rx_ch ( struct osmo_soft_uart *  suart, uint8_t  ch  )

static

References osmo_soft_uart::cfg, osmo_soft_uart::flags, osmo_soft_uart::msg, msgb_length(), msgb_put_u8(), OSMO_ASSERT, osmo_soft_uart_flush_rx(), osmo_timer_schedule(), osmo_soft_uart::rx, osmo_soft_uart_cfg::rx_buf_size, osmo_soft_uart_cfg::rx_timeout_ms, and osmo_soft_uart::timer.

Referenced by suart_rx_bit().

suart_rx_timer_cb()

static void suart_rx_timer_cb ( void *  data )

static

References data, and osmo_soft_uart_flush_rx().

Referenced by osmo_soft_uart_configure().

suart_tx_bit()

static ubit_t suart_tx_bit ( struct osmo_soft_uart *  suart, struct msgb *  msg  )

inlinestatic

References osmo_soft_uart::bit_count, osmo_soft_uart::cfg, osmo_soft_uart::flow_state, osmo_soft_uart::msg, msgb_length(), msgb_pull_u8(), osmo_soft_uart_cfg::num_data_bits, osmo_soft_uart_cfg::num_stop_bits, OSMO_ASSERT, OSMO_SUART_PARITY_EVEN, OSMO_SUART_PARITY_MARK, OSMO_SUART_PARITY_NONE, OSMO_SUART_PARITY_ODD, OSMO_SUART_PARITY_SPACE, osmo_soft_uart::parity_bit, osmo_soft_uart_cfg::parity_mode, osmo_soft_uart::shift_reg, SUART_FLOW_ST_DATA, SUART_FLOW_ST_IDLE, SUART_FLOW_ST_PARITY, SUART_FLOW_ST_STOP, and osmo_soft_uart::tx.

Referenced by osmo_soft_uart_tx_ubits(), and suart_tx_pending().

suart_tx_pending()

static size_t suart_tx_pending ( struct osmo_soft_uart *  suart, ubit_t *  ubits, size_t  n_ubits  )

static

References osmo_soft_uart::flow_state, SUART_FLOW_ST_IDLE, suart_tx_bit(), and osmo_soft_uart::tx.

Referenced by osmo_soft_uart_tx_ubits().

Variable Documentation

osmo_soft_uart_default_cfg

const struct osmo_soft_uart_cfg osmo_soft_uart_default_cfg

Initial value:

= {
        .num_data_bits = 8,
        .num_stop_bits = 1,
        .parity_mode = OSMO_SUART_PARITY_NONE,
        .rx_buf_size = 1024,
        .rx_timeout_ms = 100,
        .flow_ctrl_mode = OSMO_SUART_FLOW_CTRL_NONE,
}

Default soft-UART configuration (8-N-1)