zephyr/include/drivers/console/uart_mux.h

139 lines
3.6 KiB
C

/*
* Copyright (c) 2020 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Public APIs for UART MUX drivers
*/
#ifndef ZEPHYR_INCLUDE_DRIVERS_UART_MUX_H_
#define ZEPHYR_INCLUDE_DRIVERS_UART_MUX_H_
/**
* @brief UART Mux Interface
* @defgroup uart_mux_interface UART Mux Interface
* @ingroup io_interfaces
* @{
*/
#include <device.h>
#include <drivers/uart.h>
#ifdef __cplusplus
extern "C" {
#endif
struct gsm_dlci;
/**
* @typedef uart_mux_attach_cb_t
*
* @brief Define the user callback function which is called when
* the UART mux is attached properly.
*
* @param mux UART mux device
* @param dlci_address DLCI id for the virtual muxing channel
* @param connected True if DLCI is connected, false otherwise.
* @param user_data Arbitrary user data.
*/
typedef void (*uart_mux_attach_cb_t)(struct device *mux, int dlci_address,
bool connected, void *user_data);
/** @brief UART mux driver API structure. */
__subsystem struct uart_mux_driver_api {
/**
* The uart_driver_api must be placed in first position in this
* struct so that we are compatible with uart API. Note that currently
* not all of the UART API functions are implemented.
*/
struct uart_driver_api uart_api;
/**
* Attach the mux to this UART. The API will call the callback after
* the DLCI is created or not.
*/
int (*attach)(struct device *mux, struct device *uart,
int dlci_address, uart_mux_attach_cb_t cb,
void *user_data);
};
/**
* @brief Attach physical/real UART to UART muxing device.
*
* @param mux UART mux device structure.
* @param uart Real UART device structure.
* @param dlci_address DLCI id for the virtual muxing channel
* @param cb Callback is called when the DLCI is ready and connected
* @param user_data Caller supplied optional data
*
* @retval 0 No errors, the attachment was successful
* @retval <0 Error
*/
static inline int uart_mux_attach(struct device *mux, struct device *uart,
int dlci_address, uart_mux_attach_cb_t cb,
void *user_data)
{
const struct uart_mux_driver_api *api =
(const struct uart_mux_driver_api *)mux->driver_api;
return api->attach(mux, uart, dlci_address, cb, user_data);
}
/**
* @brief Get UART related to a specific DLCI channel
*
* @param dlci_address DLCI address, value >0 and <63
*
* @return UART device if found, NULL otherwise
*/
__syscall struct device *uart_mux_find(int dlci_address);
/**
* @brief Allocate muxing UART device.
*
* @details This will return next available uart mux driver that will mux the
* data when read or written. This device corresponds to one DLCI channel.
* User must first call this to allocate the DLCI and then call the attach
* function to fully enable the muxing.
*
* @retval device New UART device that will automatically mux data sent to it.
* @retval NULL if error
*/
struct device *uart_mux_alloc(void);
/**
* @typedef uart_mux_cb_t
* @brief Callback used while iterating over UART muxes
*
* @param uart Pointer to UART device where the mux is running
* @param dev Pointer to UART mux device
* @param dlci_address DLCI channel id this UART is muxed
* @param user_data A valid pointer to user data or NULL
*/
typedef void (*uart_mux_cb_t)(struct device *uart, struct device *dev,
int dlci_address, void *user_data);
/**
* @brief Go through all the UART muxes and call callback
* for each of them
*
* @param cb User-supplied callback function to call
* @param user_data User specified data
*/
void uart_mux_foreach(uart_mux_cb_t cb, void *user_data);
#ifdef __cplusplus
}
#endif
#include <syscalls/uart_mux.h>
/**
* @}
*/
#endif /* ZEPHYR_INCLUDE_DRIVERS_UART_MUX_H_ */