| 1 | /**************************************************************************** |
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| 2 | * This file defines a nano-driver for SocLib vci_multi_tty component, used * |
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| 3 | * by the ALMOS-MKH boot-loader. * |
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| 4 | * * |
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| 5 | * The SEG_TTY_BASE address must be defined in the 'hard_config.h' file. * |
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| 6 | * * |
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| 7 | * All accesses to the device registers are performed via 2 low-level * |
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| 8 | * functions 'boot_tty_get_register()' and 'boot_tty_set_register()'. * |
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| 9 | ****************************************************************************/ |
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| 10 | |
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| 11 | #ifndef BOOT_TTY_DRIVER_H |
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| 12 | #define BOOT_TTY_DRIVER_H |
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| 13 | |
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| 14 | #include <hal_types.h> |
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| 15 | |
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| 16 | /**************************************************************************** |
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| 17 | * Driver register map. * |
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| 18 | ****************************************************************************/ |
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| 19 | |
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| 20 | enum TTY_registers |
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| 21 | { |
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| 22 | TTY_WRITE = 0, /* character to be displayed on screen */ |
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| 23 | TTY_STATUS = 1, /* read and write buffer status */ |
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| 24 | TTY_READ = 2, /* character in the keyboard */ |
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| 25 | TTY_CONFIG = 3, /* unused */ |
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| 26 | |
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| 27 | TTY_SPAN = 4, /* segment size for one channel ( words ) */ |
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| 28 | }; |
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| 29 | |
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| 30 | /**************************************************************************** |
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| 31 | * Driver status value. * |
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| 32 | ****************************************************************************/ |
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| 33 | |
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| 34 | enum TTY_status |
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| 35 | { |
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| 36 | TTY_READ_BUSY = 1, /* Set if TTY_READ register contains a data. */ |
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| 37 | TTY_WRITE_BUSY = 2, /* Set if TTY_WRITE register contains a data. */ |
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| 38 | }; |
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| 39 | |
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| 40 | /**************************************************************************** |
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| 41 | * Driver API functions. * |
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| 42 | ****************************************************************************/ |
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| 43 | |
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| 44 | /**************************************************************************** |
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| 45 | * This function writes a character string from the 'buf' buffer to the * |
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| 46 | * boot TTY terminal. It tests the TTY_STATUS register before writing each * |
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| 47 | * character of the string to the TTY_WRITE register. If TTY_WRITE_BUSY * |
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| 48 | * bit is set, it keeps testing the TTY_STATUS register. If after 10000 * |
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| 49 | * retries the bit is still set, the function reports an error and returns. * |
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| 50 | * @ buf : buffer containing the string to be printed * |
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| 51 | * @ nbytes : number of characters to be printed * |
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| 52 | * @ returns 0 on success, -1 on error. * |
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| 53 | ****************************************************************************/ |
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| 54 | int boot_tty_write( char * buf, |
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| 55 | uint32_t nbytes ); |
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| 56 | |
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| 57 | #endif // BOOT_TTY_DRIVER_H |
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