| 1 | /////////////////////////////////////////////////////////////////////////////////// |
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| 2 | // File : boot_tty_driver.c |
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| 3 | // Date : 18/01/2017 |
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| 4 | // Author : Alain Greiner / Vu Son |
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| 5 | // Copyright (c) UPMC-LIP6 |
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| 6 | /////////////////////////////////////////////////////////////////////////////////// |
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| 7 | |
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| 8 | #include <boot_config.h> |
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| 9 | #include <boot_tty_driver.h> |
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| 10 | #include <hal_types.h> |
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| 11 | #include <boot_utils.h> |
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| 12 | |
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| 13 | #ifndef SEG_TTY_BASE |
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| 14 | # error "The SEG_TTY_BASE value should be defined in the 'boot_config.h' file" |
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| 15 | #endif |
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| 16 | |
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| 17 | #ifndef IO_CXY |
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| 18 | # error "The IO_CXY value should be defined in the 'boot_config.h' file" |
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| 19 | #endif |
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| 20 | |
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| 21 | |
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| 22 | /**************************************************************************** |
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| 23 | * Internal functions. * |
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| 24 | ****************************************************************************/ |
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| 25 | |
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| 26 | /**************************************************************************** |
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| 27 | * This function returns the value of the a TTY register. * |
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| 28 | * @ reg : TTY register to be read. * |
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| 29 | * @ returns the value stored in 'reg'. * |
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| 30 | ****************************************************************************/ |
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| 31 | static uint32_t boot_tty_get_register( uint32_t reg ) |
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| 32 | { |
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| 33 | cxy_t cxy = IO_CXY; |
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| 34 | uint32_t * ptr = (uint32_t *)SEG_TTY_BASE + reg; |
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| 35 | |
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| 36 | return boot_remote_lw( XPTR( cxy , ptr ) ); |
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| 37 | |
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| 38 | } // boot_tty_get_register() |
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| 39 | |
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| 40 | /**************************************************************************** |
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| 41 | * This function sets a new value to a TTY register. * |
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| 42 | * @ reg : TTY register to be configured. * |
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| 43 | * @ val : new value to be written to 'reg'. * |
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| 44 | ****************************************************************************/ |
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| 45 | static void boot_tty_set_register( uint32_t reg, |
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| 46 | uint32_t val ) |
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| 47 | { |
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| 48 | cxy_t cxy = IO_CXY; |
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| 49 | uint32_t * ptr = (uint32_t *)SEG_TTY_BASE + reg; |
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| 50 | |
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| 51 | boot_remote_sw( XPTR( cxy , ptr ) , val ); |
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| 52 | |
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| 53 | } // boot_tty_set_register() |
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| 54 | |
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| 55 | /**************************************************************************** |
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| 56 | * Driver API functions. * |
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| 57 | ****************************************************************************/ |
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| 58 | |
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| 59 | int boot_tty_write( char * buf, |
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| 60 | uint32_t nbytes ) |
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| 61 | { |
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| 62 | uint32_t nb_printed; /* Iterator for printing loop. */ |
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| 63 | uint32_t nb_test; /* Iterator for retry loop. */ |
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| 64 | uint32_t error; /* Used to detect if an error occurs. */ |
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| 65 | |
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| 66 | /* Printing to the boot TTY terminal. */ |
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| 67 | for (nb_printed = 0; nb_printed < nbytes; nb_printed++) |
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| 68 | { |
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| 69 | // Polling the TTY driver status. |
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| 70 | if ((boot_tty_get_register(TTY_STATUS) & TTY_WRITE_BUSY)) |
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| 71 | { |
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| 72 | // TTY_WRITE_BUSY bit of TTY_STATUS register is set, keeps polling. |
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| 73 | error = 1; |
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| 74 | for (nb_test = 0; nb_test < 10000; nb_test++) |
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| 75 | if ((boot_tty_get_register(TTY_STATUS) & TTY_WRITE_BUSY) == 0) |
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| 76 | { |
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| 77 | error = 0; |
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| 78 | break; |
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| 79 | } |
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| 80 | |
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| 81 | // Reporting an error if the TTY_WRITE_BUSY bit is still set after |
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| 82 | // 10000 retries. |
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| 83 | if (error) |
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| 84 | return -1; |
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| 85 | } |
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| 86 | |
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| 87 | // Writing a character to the boot TTY terminal. |
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| 88 | // Special treatment for a newline: Carriage Return before Line Feed. |
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| 89 | if (buf[nb_printed] == '\n') |
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| 90 | boot_tty_set_register(TTY_WRITE, (uint32_t)'\r'); |
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| 91 | boot_tty_set_register(TTY_WRITE, (uint32_t)buf[nb_printed]); |
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| 92 | } |
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| 93 | |
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| 94 | return 0; |
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| 95 | |
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| 96 | } // boot_tty_write() |
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