From 8d190cdbb9c4e4377d0c33424e453c5ac166eed8 Mon Sep 17 00:00:00 2001 From: Gareth McMullin Date: Sun, 10 Jun 2012 16:40:07 +1200 Subject: Renamed platforms to 'native' and 'libftdi' and moved into 'platforms' dir. --- src/platforms/native/swdptap.c | 155 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 src/platforms/native/swdptap.c (limited to 'src/platforms/native/swdptap.c') diff --git a/src/platforms/native/swdptap.c b/src/platforms/native/swdptap.c new file mode 100644 index 0000000..8ac78b2 --- /dev/null +++ b/src/platforms/native/swdptap.c @@ -0,0 +1,155 @@ +/* + * This file is part of the Black Magic Debug project. + * + * Copyright (C) 2011 Black Sphere Technologies Ltd. + * Written by Gareth McMullin + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +/* This file implements the low-level SW-DP interface. */ + +#include + +#include "general.h" + +#include "swdptap.h" + +#include "gdb_packet.h" + +static void swdptap_turnaround(uint8_t dir) +{ + static uint8_t olddir = 0; + + DEBUG("%s", dir ? "\n-> ":"\n<- "); + + /* Don't turnaround if direction not changing */ + if(dir == olddir) return; + olddir = dir; + + if(dir) + gpio_set_mode(SWDP_PORT, GPIO_MODE_INPUT, + GPIO_CNF_INPUT_FLOAT, SWDIO_PIN); + gpio_set(SWDP_PORT, SWCLK_PIN); + gpio_clear(SWDP_PORT, SWCLK_PIN); + if(!dir) + gpio_set_mode(SWDP_PORT, GPIO_MODE_OUTPUT_50_MHZ, + GPIO_CNF_OUTPUT_PUSHPULL, SWDIO_PIN); +} + +static uint8_t swdptap_bit_in(void) +{ + uint8_t ret; + + ret = gpio_get(SWDP_PORT, SWDIO_PIN); + gpio_set(SWDP_PORT, SWCLK_PIN); + gpio_clear(SWDP_PORT, SWCLK_PIN); + + DEBUG("%d", ret?1:0); + + return ret; +} + +static void swdptap_bit_out(uint8_t val) +{ + DEBUG("%d", val); + + gpio_set_val(SWDP_PORT, SWDIO_PIN, val); + gpio_set(SWDP_PORT, SWCLK_PIN); + gpio_clear(SWDP_PORT, SWCLK_PIN); +} + +int swdptap_init(void) +{ + /* This must be investigated in more detail. + * As described in STM32 Reference Manual... */ + swdptap_reset(); + swdptap_seq_out(0xE79E, 16); /* 0b0111100111100111 */ + swdptap_reset(); + swdptap_seq_out(0, 16); + + return 0; +} + + +void swdptap_reset(void) +{ + swdptap_turnaround(0); + /* 50 clocks with TMS high */ + for(int i = 0; i < 50; i++) swdptap_bit_out(1); +} + + +uint32_t swdptap_seq_in(int ticks) +{ + uint32_t index = 1; + uint32_t ret = 0; + + swdptap_turnaround(1); + + while(ticks--) { + if(swdptap_bit_in()) ret |= index; + index <<= 1; + } + + return ret; +} + + +uint8_t swdptap_seq_in_parity(uint32_t *ret, int ticks) +{ + uint32_t index = 1; + uint8_t parity = 0; + *ret = 0; + + swdptap_turnaround(1); + + while(ticks--) { + if(swdptap_bit_in()) { + *ret |= index; + parity ^= 1; + } + index <<= 1; + } + if(swdptap_bit_in()) parity ^= 1; + + return parity; +} + + +void swdptap_seq_out(uint32_t MS, int ticks) +{ + swdptap_turnaround(0); + + while(ticks--) { + swdptap_bit_out(MS & 1); + MS >>= 1; + } +} + + +void swdptap_seq_out_parity(uint32_t MS, int ticks) +{ + uint8_t parity = 0; + + swdptap_turnaround(0); + + while(ticks--) { + swdptap_bit_out(MS & 1); + parity ^= MS; + MS >>= 1; + } + swdptap_bit_out(parity & 1); +} + -- cgit v1.2.3