| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * |
| 3 | * BRIEF MODULE DESCRIPTION |
| 4 | * Low level uart routines to directly access a 16550 uart. |
| 5 | * |
| 6 | * Copyright 2000,2001 MontaVista Software Inc. |
| 7 | * Author: MontaVista Software, Inc. |
| 8 | * ppopov@mvista.com or source@mvista.com |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify it |
| 11 | * under the terms of the GNU General Public License as published by the |
| 12 | * Free Software Foundation; either version 2 of the License, or (at your |
| 13 | * option) any later version. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 16 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 17 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN |
| 18 | * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 19 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 20 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| 21 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
| 22 | * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 24 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 25 | * |
| 26 | * You should have received a copy of the GNU General Public License along |
| 27 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 28 | * 675 Mass Ave, Cambridge, MA 02139, USA. |
| 29 | */ |
| 30 | |
| 31 | #include <linux/types.h> |
| 32 | |
| 33 | #define SERIAL_BASE 0xB4011800 /* it8172 */ |
| 34 | #define SER_CMD 5 |
| 35 | #define SER_DATA 0x00 |
| 36 | #define TX_BUSY 0x20 |
| 37 | |
| 38 | #define TIMEOUT 0xffff |
| 39 | #undef SLOW_DOWN |
| 40 | |
| 41 | static const char digits[16] = "0123456789abcdef"; |
| 42 | static volatile unsigned char *const com1 = (unsigned char *) SERIAL_BASE; |
| 43 | |
| 44 | |
| 45 | #ifdef SLOW_DOWN |
| 46 | static inline void slow_down() |
| 47 | { |
| 48 | int k; |
| 49 | for (k = 0; k < 10000; k++); |
| 50 | } |
| 51 | #else |
| 52 | #define slow_down() |
| 53 | #endif |
| 54 | |
| 55 | void putch(const unsigned char c) |
| 56 | { |
| 57 | unsigned char ch; |
| 58 | int i = 0; |
| 59 | |
| 60 | do { |
| 61 | ch = com1[SER_CMD]; |
| 62 | slow_down(); |
| 63 | i++; |
| 64 | if (i > TIMEOUT) { |
| 65 | break; |
| 66 | } |
| 67 | } while (0 == (ch & TX_BUSY)); |
| 68 | com1[SER_DATA] = c; |
| 69 | } |
| 70 | |
| 71 | void puts(unsigned char *cp) |
| 72 | { |
| 73 | unsigned char ch; |
| 74 | int i = 0; |
| 75 | |
| 76 | while (*cp) { |
| 77 | do { |
| 78 | ch = com1[SER_CMD]; |
| 79 | slow_down(); |
| 80 | i++; |
| 81 | if (i > TIMEOUT) { |
| 82 | break; |
| 83 | } |
| 84 | } while (0 == (ch & TX_BUSY)); |
| 85 | com1[SER_DATA] = *cp++; |
| 86 | } |
| 87 | putch('\r'); |
| 88 | putch('\n'); |
| 89 | } |
| 90 | |
| 91 | void fputs(unsigned char *cp) |
| 92 | { |
| 93 | unsigned char ch; |
| 94 | int i = 0; |
| 95 | |
| 96 | while (*cp) { |
| 97 | |
| 98 | do { |
| 99 | ch = com1[SER_CMD]; |
| 100 | slow_down(); |
| 101 | i++; |
| 102 | if (i > TIMEOUT) { |
| 103 | break; |
| 104 | } |
| 105 | } while (0 == (ch & TX_BUSY)); |
| 106 | com1[SER_DATA] = *cp++; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | |
| 111 | void put64(uint64_t ul) |
| 112 | { |
| 113 | int cnt; |
| 114 | unsigned ch; |
| 115 | |
| 116 | cnt = 16; /* 16 nibbles in a 64 bit long */ |
| 117 | putch('0'); |
| 118 | putch('x'); |
| 119 | do { |
| 120 | cnt--; |
| 121 | ch = (unsigned char) (ul >> cnt * 4) & 0x0F; |
| 122 | putch(digits[ch]); |
| 123 | } while (cnt > 0); |
| 124 | } |
| 125 | |
| 126 | void put32(unsigned u) |
| 127 | { |
| 128 | int cnt; |
| 129 | unsigned ch; |
| 130 | |
| 131 | cnt = 8; /* 8 nibbles in a 32 bit long */ |
| 132 | putch('0'); |
| 133 | putch('x'); |
| 134 | do { |
| 135 | cnt--; |
| 136 | ch = (unsigned char) (u >> cnt * 4) & 0x0F; |
| 137 | putch(digits[ch]); |
| 138 | } while (cnt > 0); |
| 139 | } |