| [1] | 1 | /* |
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| 2 | * soclib_tty.c - soclib tty driver definition. |
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| 3 | * |
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| 4 | * Author Alain Greiner (2016) |
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| 5 | * |
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| 6 | * Copyright (c) UPMC Sorbonne Universites |
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| 7 | * |
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| 8 | * This file is part of ALMOS-MKH. |
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| 9 | * |
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| 10 | * ALMOS-MKH is free software; you can redistribute it and/or modify it |
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| 11 | * under the terms of the GNU General Public License as published by |
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| 12 | * the Free Software Foundation; version 2.0 of the License. |
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| 13 | * |
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| 14 | * ALMOS-MKH is distributed in the hope that it will be useful, but |
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| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 17 | * General Public License for more details. |
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| 18 | * |
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| 19 | * You should have received a copy of the GNU General Public License |
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| 20 | * along with ALMOS-kernel; if not, write to the Free Software Foundation, |
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| 21 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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| 22 | */ |
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| 23 | |
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| 24 | #include <dev_txt.h> |
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| 25 | #include <device.h> |
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| 26 | #include <spinlock.h> |
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| 27 | |
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| 28 | |
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| 29 | /**************************************************************************************** |
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| 30 | * This driver supports the soclib_multi_tty component. |
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| 31 | * It implements the generic TXT device API: |
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| 32 | * - transfer one single character from TTY to command "buffer" if to_mem is non-zero. |
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| 33 | * - transfer "count" characters from command "buffer" to TTY if "to_mem is zero. |
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| 34 | ***************************************************************************************/ |
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| 35 | |
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| 36 | /**************************************************************************************** |
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| 37 | * SOCLIB_TTY registers offsets |
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| 38 | ***************************************************************************************/ |
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| 39 | |
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| 40 | #define TTY_WRITE_REG 0 |
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| 41 | #define TTY_STATUS_REG 1 |
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| 42 | #define TTY_READ_REG 2 |
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| 43 | #define TTY_CONFIG_REG 3 |
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| 44 | |
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| 45 | #define TTY_SPAN 4 // number of registers per channel |
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| 46 | |
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| 47 | /**************************************************************************************** |
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| 48 | * masks for TTY_STATUS_REG |
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| 49 | ***************************************************************************************/ |
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| 50 | |
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| 51 | #define TTY_STATUS_RX_FULL 1 // TTY_READ_REG full if 1 |
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| 52 | #define TTY_STATUS_TX_FULL 2 // TTY_WRITE_REG full if 1 |
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| 53 | |
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| 54 | /**************************************************************************************** |
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| 55 | * masks for TTY_CONFIG_REG |
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| 56 | ***************************************************************************************/ |
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| 57 | |
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| 58 | #define TTY_CONFIG_RX_ENABLE 1 // TTY_RX IRQ enabled if 1 |
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| 59 | #define TTY_CONFIG_TX_ENABLE 2 // TTY_TX IRQ enabled if 1 |
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| 60 | |
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| 61 | /**************************************************************************************** |
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| 62 | * This function masks both the TTY_RX and TTY_TX IRQs from the SOCLIB_TTY device. |
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| 63 | * Thes IRQs are unmasked by the soclib_tty_cmd() function. |
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| 64 | **************************************************************************************** |
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| 65 | * @ dev : extended pointer on the generic TXT device descriptor. |
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| 66 | ***************************************************************************************/ |
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| 67 | extern void soclib_tty_init( xptr_t dev_xp ); |
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| 68 | |
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| 69 | /**************************************************************************************** |
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| 70 | * This function handles the command registered in the thread descriptor identified |
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| 71 | * by the <xp_thread> argument. |
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| 72 | * - For the TXT_READ and TXT_WRITE commands, it only unmask the proper TTY_RX / TTY_TX |
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| 73 | * IRQ, and blocks the TXT device server thread on the THREAD_BLOCKED_DEV_ISR, as the |
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| 74 | * data transfer is done by the ISR. |
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| 75 | * - For the TXT_SYNC_READ command, that should be only used by the kernel do display |
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| 76 | * log or debug messages, it directly access the SOCLIB_TTY registers, using |
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| 77 | * a busy waiting policy if required. |
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| 78 | **************************************************************************************** |
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| 79 | * @ xp_thread : extended pointer on client thread descriptor. |
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| 80 | ***************************************************************************************/ |
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| 81 | extern void soclib_tty_command( xptr_t thread_xp ); |
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| 82 | |
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| 83 | /**************************************************************************************** |
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| 84 | * This ISR should be executed only for the TXT_READ and TXT_WRITE commands. |
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| 85 | * It get the command arguments from the first client thread in the TXT device queue: |
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| 86 | * - if TXT_READ, it transfer one byte from the TTY_READ_REG to the command buffer. |
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| 87 | * It simply returns for retry if TTY_READ_REG is empty. |
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| 88 | * - if TXT_WRITE, it tries to transfer several bytes from the command buffer to the |
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| 89 | * TTY_WRITE_REG. If the TTY_WRITE_REG is full, it updates the "count" and "buffer" |
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| 90 | * command arguments and returns for retry. |
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| 91 | * When the I/O operation is completed, it set the status field in the command, unblock |
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| 92 | * the server thread, and unblock the client thread. |
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| 93 | **************************************************************************************** |
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| 94 | * @ dev : local pointer on generic TXT device descriptor. |
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| 95 | ***************************************************************************************/ |
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| 96 | extern void soclib_tty_isr( device_t * dev ); |
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| 97 | |
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