1 | /* |
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2 | * boot_tty_driver.h - TSAR bootloader TTY driver definition. |
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3 | * |
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4 | * Authors : Alain Greiner / Vu Son (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-MKH; 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 | /**************************************************************************** |
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25 | * This file defines a nano-driver for SocLib vci_multi_tty component, |
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26 | * used by the ALMOS-MKH boot-loader. |
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27 | * The SEG_TTY_BASE address must be defined in the 'hard_config.h' file. |
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28 | * All accesses to the device registers are performed via 2 low-level |
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29 | * functions 'boot_tty_get_register()' and 'boot_tty_set_register()'. |
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30 | ****************************************************************************/ |
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31 | |
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32 | #ifndef BOOT_TTY_DRIVER_H |
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33 | #define BOOT_TTY_DRIVER_H |
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34 | |
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35 | #include <hal_kernel_types.h> |
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36 | |
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37 | /**************************************************************************** |
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38 | * Driver register map. * |
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39 | ****************************************************************************/ |
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40 | |
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41 | enum TTY_registers |
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42 | { |
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43 | TTY_WRITE_REG = 0, /* character to be displayed on screen */ |
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44 | TTY_STATUS_REG = 1, /* read and write buffer status */ |
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45 | TTY_READ_REG = 2, /* character in the keyboard */ |
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46 | TTY_CONFIG_REG = 3, /* unused */ |
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47 | |
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48 | TTY_SPAN = 4, /* segment size for one channel ( words ) */ |
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49 | }; |
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50 | |
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51 | /**************************************************************************** |
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52 | * Driver status value. * |
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53 | ****************************************************************************/ |
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54 | |
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55 | enum TTY_status |
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56 | { |
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57 | TTY_STATUS_RX_FULL = 1, /* Set if TTY_READ register contains a data. */ |
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58 | TTY_STATUS_TX_FULL = 2, /* Set if TTY_WRITE register contains a data. */ |
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59 | }; |
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60 | |
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61 | /**************************************************************************** |
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62 | * This function writes a character string from the 'buf' buffer to the |
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63 | * boot TTY terminal. It tests the TTY_STATUS register before writing each |
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64 | * character of the string to the TTY_WRITE register. If TTY_WRITE_BUSY |
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65 | * bit is set, it keeps testing the TTY_STATUS register. If after 10000 |
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66 | * retries the bit is still set, the function reports an error and returns. |
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67 | **************************************************************************** |
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68 | * @ buf : buffer containing the string to be printed. |
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69 | * @ nbytes : number of characters to be printed. |
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70 | * @ returns 0 on success, -1 on error. |
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71 | ****************************************************************************/ |
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72 | int boot_tty_write( const char * buf, |
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73 | uint32_t nbytes ); |
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74 | |
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75 | #endif // BOOT_TTY_DRIVER_H |
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