C8051F32x firmware infrastructure
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| 1 | /* |
| 2 | * f32x/c2-bitbang.c - Basic C2 messages, bitbang |
| 3 | * |
| 4 | * Written 2008, 2010 by Werner Almesberger |
| 5 | * Copyright 2008, 2010 Werner Almesberger |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | */ |
| 12 | |
| 13 | /* |
| 14 | * This file is meant to be #included by a .c file that defines C2CK and C2D, |
| 15 | * provides the gpio_* functions, etc. |
| 16 | */ |
| 17 | |
| 18 | |
| 19 | #include <stdint.h> |
| 20 | #include <unistd.h> |
| 21 | |
| 22 | |
| 23 | /* ----- Bit-level operations ---------------------------------------------- */ |
| 24 | |
| 25 | |
| 26 | static void c2_pulse(void) |
| 27 | { |
| 28 | gpio_low(C2CK); |
| 29 | gpio_high(C2CK); |
| 30 | } |
| 31 | |
| 32 | |
| 33 | static void c2_send(uint32_t value, int bits) |
| 34 | { |
| 35 | int i; |
| 36 | |
| 37 | for (i = 0; i != bits; i++) { |
| 38 | gpio_set(C2D, (value >> i) & 1); |
| 39 | c2_pulse(); |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | |
| 44 | static uint32_t c2_recv(int bits) |
| 45 | { |
| 46 | uint32_t v = 0; |
| 47 | int i; |
| 48 | |
| 49 | for (i = 0; i != bits; i++) { |
| 50 | v |= gpio_get(C2D) << i; |
| 51 | c2_pulse(); |
| 52 | } |
| 53 | return v; |
| 54 | } |
| 55 | |
| 56 | |
| 57 | /* ----- C2 Register read/write -------------------------------------------- */ |
| 58 | |
| 59 | |
| 60 | static void c2_addr_write(uint8_t addr) |
| 61 | { |
| 62 | c2_pulse(); |
| 63 | gpio_output(C2D); |
| 64 | c2_send(C2_ADDR_WRITE, 2); |
| 65 | c2_send(addr, 8); |
| 66 | gpio_input(C2D); |
| 67 | c2_pulse(); |
| 68 | } |
| 69 | |
| 70 | |
| 71 | static uint8_t c2_addr_read(void) |
| 72 | { |
| 73 | c2_pulse(); |
| 74 | gpio_output(C2D); |
| 75 | c2_send(C2_ADDR_READ, 2); |
| 76 | gpio_input(C2D); |
| 77 | c2_pulse(); |
| 78 | return c2_recv(8); |
| 79 | } |
| 80 | |
| 81 | |
| 82 | static void c2_data_write(uint32_t data, int bytes) |
| 83 | { |
| 84 | c2_pulse(); |
| 85 | gpio_output(C2D); |
| 86 | c2_send(C2_DATA_WRITE, 2); |
| 87 | c2_send(bytes-1, 2); |
| 88 | c2_send(data, 8*bytes); |
| 89 | gpio_input(C2D); |
| 90 | c2_pulse(); |
| 91 | while (!c2_recv(1)); |
| 92 | } |
| 93 | |
| 94 | |
| 95 | static uint32_t c2_data_read(int bytes) |
| 96 | { |
| 97 | c2_pulse(); |
| 98 | gpio_output(C2D); |
| 99 | c2_send(C2_DATA_READ, 2); |
| 100 | c2_send(bytes-1, 2); |
| 101 | gpio_input(C2D); |
| 102 | c2_pulse(); |
| 103 | while (!c2_recv(1)); |
| 104 | return c2_recv(8*bytes); |
| 105 | } |
| 106 | |
| 107 | |
| 108 | /* ----- C2 initialization ------------------------------------------------- */ |
| 109 | |
| 110 | |
| 111 | static void c2_init(void) |
| 112 | { |
| 113 | gpio_input(C2D); |
| 114 | gpio_output(C2CK); |
| 115 | gpio_low(C2CK); |
| 116 | usleep(20); |
| 117 | gpio_high(C2CK); |
| 118 | usleep(2); |
| 119 | } |
| 120 | |
| 121 | |
| 122 | static void c2_reset(void) |
| 123 | { |
| 124 | gpio_input(C2D); |
| 125 | gpio_low(C2CK); |
| 126 | usleep(20); |
| 127 | // gpio_input(C2CK); |
| 128 | gpio_output(C2CK); |
| 129 | gpio_high(C2CK); |
| 130 | } |
| 131 |
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