/* * dev_txt.h - TXT (Text Terminal) generic device API definition. * * Author Alain Greiner (2016) * * Copyright (c) UPMC Sorbonne Universites * * This file is part of ALMOS-MKH * * ALMOS-MKH is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2.0 of the License. * * ALMOS-MKH 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. * * You should have received a copy of the GNU General Public License * along with ALMOS-kernel; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef _DEV_TXT_H_ #define _DEV_TXT_H_ #include #include /**** Forward declarations ****/ struct chdev_s ; /****************************************************************************************** * Generic Text Terminal device definition. * * This multi-channels generic TXT device provides access to a text terminal. * It supports three operation types : * - TXT_READ : read a single character from the text terminal identified by its channel * index, using a descheduling strategy for the calling thread. * - TXT_WRITE : write a character string to the text terminal identified by its channel * index, using a descheduling strategy for the calling thread. * - TXT_SYNC_WRITE : write a character string to the terminal identified by its channel * index, using a busy waiting strategy for the calling thread. *****************************************************************************************/ /****************************************************************************************** * This enum defines the various implementations of the generic TXT peripheral. * This array must be kept consistent with the define in arch_info.h file *****************************************************************************************/ enum txt_impl_e { IMPL_TXT_TTY = 0, IMPL_TXT_X86 = 1, } txt_impl_t; /****************************************************************************************** * This defines the (implementation independent) command passed to the driver. *****************************************************************************************/ enum { TXT_READ = 0, TXT_WRITE = 1, TXT_SYNC_WRITE = 2, }; typedef struct txt_command_s { xptr_t dev_xp; /*! extended pointer on the relevant TXT device descriptor */ uint32_t type; /*! TXT_READ / TXT_WRITE / TXT_SYNC_WRITE */ xptr_t buf_xp; /*! extended pointer on characters array */ uint32_t count; /*! number of characters in buffer (must be 1 if to_mem) */ uint32_t error; /*! operation status (0 if success) */ } txt_command_t; /****************************************************************************************** * This function completes the TXT chdev descriptor initialisation, * namely the link with the implementation specific driver. * The func, impl, channel, is_rxt, base fields have been previously initialised. * It calls the specific driver initialisation function, to initialise the hardware * device and the driver specific data structures when required. * It creates the associated server thread and allocates a WTI from local ICU. * It must de executed by a local thread. ****************************************************************************************** * @ chdev : local pointer on TXT device descriptor. *****************************************************************************************/ void dev_txt_init( struct chdev_s * chdev ); /****************************************************************************************** * This blocking function reads a single character from the terminal identified * by the "channel" argument. The corresponding request is actually registered in the * chdev requests queue, and the calling thread is descheduled, blocked until * transfer completion. * It must be called in the client cluster. ****************************************************************************************** * @ channel : TXT channel index. * @ buffer : local pointer on destination buffer for the character. * @ returns 0 if success / returns EINVAL if error. *****************************************************************************************/ error_t dev_txt_read( uint32_t channel, char * buffer ); /****************************************************************************************** * This blocking function writes characters on the terminal identified * by the "channel" argument. The corresponding request is actually registered in the * chdev requests queue, and the calling thread is descheduled, blocked until * transfer completion. * It must be called in the client cluster. ****************************************************************************************** * @ channel : TXT channel index. * @ buffer : local pointer on source buffer containing the string. * @ count : number of characters. * @ returns 0 if success / returns EINVAL if error. ****************************************************************************************/ error_t dev_txt_write( uint32_t channel, char * buffer, uint32_t count ); /*************************************************************************************** * This low-level blocking function is used by the kernel to display one string on a * given TXT channel without descheduling the calling thread, without registering it * in the TXT device waiting queue, and without using the TXT irq. **************************************************************************************** * @ channel : TXT channel index. * @ buffer : local pointer on source buffer containing the string. * @ count : number of characters. * @ returns 0 if success / returns EINVAL if error. ***************************************************************************************/ error_t dev_txt_sync_write( uint32_t channel, char * buffer, uint32_t count ); #endif /* _DEV_TXT_H_ */