/* * soclib_tty.c - soclib tty driver 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 */ #include #include #include /**************************************************************************************** * This driver supports the soclib_multi_tty component. * It implements the generic TXT device API: * - transfer one single character from TTY to command "buffer" if to_mem is non-zero. * - transfer "count" characters from command "buffer" to TTY if "to_mem is zero. ***************************************************************************************/ /**************************************************************************************** * SOCLIB_TTY registers offsets ***************************************************************************************/ #define TTY_WRITE 0 #define TTY_STATUS 1 #define TTY_READ 2 #define TTY_RX_IRQ_ENABLE 3 #define TTY_TX_IRQ_ENABLE 4 #define TTY_SPAN 8 // number of registers per channel /**************************************************************************************** * masks for TTY_STATUS_REG ***************************************************************************************/ #define TTY_STATUS_RX_FULL 1 // TTY_READ_REG full if 1 #define TTY_STATUS_TX_FULL 2 // TTY_WRITE_REG full if 1 /**************************************************************************************** * This function masks both the TTY_RX and TTY_TX IRQs. * These IRQs are unmasked by the soclib_tty_cmd() function. **************************************************************************************** * @ chdev : pointer on the TXT chdev descriptor. ***************************************************************************************/ void soclib_tty_init( chdev_t * chdev ); /**************************************************************************************** * This function implements the TXT_READ & TXT_WRITE commands registered in the client * thread descriptor (in the txt_cmd field), identified by the argument. * Depending on the command type, it only unmasks the relevant TTY_RX / TTY_TX IRQ, * and blocks the TXT device server thread on the THREAD_BLOCKED_DEV_ISR, as the data * transfer is done by the ISR. * **************************************************************************************** * @ thread_xp : extended pointer on client thread descriptor. ***************************************************************************************/ void soclib_tty_cmd( xptr_t thread_xp ); /**************************************************************************************** * This function implements the TXT_SYNC_WRITE command registered in the txt_aux_t * structure, using a busy waiting policy, without using the TTY IRQ. * It is used by the kernel do display debug messages on TXT0 terminal, without * interference with another TXT access to another terminal done by the same thread. **************************************************************************************** * @ thread_xp : pointer on the txt_aux_t structure containing the arguments. ***************************************************************************************/ void soclib_tty_aux( void * args ); /**************************************************************************************** * This ISR should be executed only for the TXT_READ and TXT_WRITE commands. * It gets the command arguments from the first client thread in the TXT chdev queue: * - if TXT_READ, it transfers one byte from the TTY_READ_REG to the command buffer. * It simply returns for retry if TTY_READ_REG is empty. * - if TXT_WRITE, it tries to transfer several bytes from the command buffer to the * TTY_WRITE_REG. If the TTY_WRITE_REG is full, it updates the "count" and "buffer" * command arguments and returns for retry. * When the I/O operation is completed, it sets the status field in the command, unblocks * the server thread, and unblocks the client thread. **************************************************************************************** * @ chdev : local pointer on TXT chdev descriptor. ***************************************************************************************/ void soclib_tty_isr( chdev_t * chdev );