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Diffstat (limited to 'wirish/usb_serial.cpp')
| -rw-r--r-- | wirish/usb_serial.cpp | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/wirish/usb_serial.cpp b/wirish/usb_serial.cpp new file mode 100644 index 0000000..3bb1923 --- /dev/null +++ b/wirish/usb_serial.cpp @@ -0,0 +1,286 @@ +/****************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Perry Hung. + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + *****************************************************************************/ + +/** + * @brief USB virtual serial terminal + */ + +#include <wirish/usb_serial.h> + +#include <string.h> +#include <stdint.h> + +#include <libmaple/nvic.h> +#include <libmaple/usb_cdcacm.h> +#include <libmaple/usb.h> +#include <libmaple/iwdg.h> + +#include <wirish/wirish.h> + +/* + * Hooks used for bootloader reset signalling + */ + +#if BOARD_HAVE_SERIALUSB +static void rxHook(unsigned, void*); +static void ifaceSetupHook(unsigned, void*); +#endif + +/* + * USBSerial interface + */ + +#define USB_TIMEOUT 50 + +USBSerial::USBSerial(void) { +#if !BOARD_HAVE_SERIALUSB + ASSERT(0); +#endif +} + +void USBSerial::begin(void) { +#if BOARD_HAVE_SERIALUSB + usb_cdcacm_enable(BOARD_USB_DISC_DEV, BOARD_USB_DISC_BIT); + usb_cdcacm_set_hooks(USB_CDCACM_HOOK_RX, rxHook); + usb_cdcacm_set_hooks(USB_CDCACM_HOOK_IFACE_SETUP, ifaceSetupHook); +#endif +} + +void USBSerial::end(void) { +#if BOARD_HAVE_SERIALUSB + usb_cdcacm_disable(BOARD_USB_DISC_DEV, BOARD_USB_DISC_BIT); + usb_cdcacm_remove_hooks(USB_CDCACM_HOOK_RX | USB_CDCACM_HOOK_IFACE_SETUP); +#endif +} + +void USBSerial::write(uint8 ch) { + this->write(&ch, 1); +} + +void USBSerial::write(const char *str) { + this->write(str, strlen(str)); +} + +void USBSerial::write(const void *buf, uint32 len) { + if (!this->isConnected() || !buf) { + return; + } + + uint32 txed = 0; + uint32 old_txed = 0; + uint32 start = millis(); + + uint32 sent = 0; + + while (txed < len && (millis() - start < USB_TIMEOUT)) { + sent = usb_cdcacm_tx((const uint8*)buf + txed, len - txed); + txed += sent; + if (old_txed != txed) { + start = millis(); + } + old_txed = txed; + } + + + if (sent == USB_CDCACM_TX_EPSIZE) { + while (usb_cdcacm_is_transmitting() != 0) { + } + /* flush out to avoid having the pc wait for more data */ + usb_cdcacm_tx(NULL, 0); + } +} + +uint32 USBSerial::available(void) { + return usb_cdcacm_data_available(); +} + +uint32 USBSerial::read(void *buf, uint32 len) { + if (!buf) { + return 0; + } + + uint32 rxed = 0; + while (rxed < len) { + rxed += usb_cdcacm_rx((uint8*)buf + rxed, len - rxed); + } + + return rxed; +} + +/* Blocks forever until 1 byte is received */ +uint8 USBSerial::read(void) { + uint8 b; + this->read(&b, 1); + return b; +} + +uint8 USBSerial::pending(void) { + return usb_cdcacm_get_pending(); +} + +uint8 USBSerial::isConnected(void) { + return usb_is_connected(USBLIB) && usb_is_configured(USBLIB); +} + +uint8 USBSerial::getDTR(void) { + return usb_cdcacm_get_dtr(); +} + +uint8 USBSerial::getRTS(void) { + return usb_cdcacm_get_rts(); +} + +#if BOARD_HAVE_SERIALUSB +USBSerial SerialUSB; +#endif + +/* + * Bootloader hook implementations + */ + +#if BOARD_HAVE_SERIALUSB + +enum reset_state_t { + DTR_UNSET, + DTR_HIGH, + DTR_NEGEDGE, + DTR_LOW +}; + +static reset_state_t reset_state = DTR_UNSET; + +static void ifaceSetupHook(unsigned hook, void *requestvp) { + uint8 request = *(uint8*)requestvp; + + // Ignore requests we're not interested in. + if (request != USB_CDCACM_SET_CONTROL_LINE_STATE) { + return; + } + +#if defined(BOOTLOADER_maple) + // We need to see a negative edge on DTR before we start looking + // for the in-band magic reset byte sequence. + uint8 dtr = usb_cdcacm_get_dtr(); + switch (reset_state) { + case DTR_UNSET: + reset_state = dtr ? DTR_HIGH : DTR_LOW; + break; + case DTR_HIGH: + reset_state = dtr ? DTR_HIGH : DTR_NEGEDGE; + break; + case DTR_NEGEDGE: + reset_state = dtr ? DTR_HIGH : DTR_LOW; + break; + case DTR_LOW: + reset_state = dtr ? DTR_HIGH : DTR_LOW; + break; + } +#endif + +#if defined(BOOTLOADER_robotis) + uint8 dtr = usb_cdcacm_get_dtr(); + uint8 rts = usb_cdcacm_get_rts(); + + if (rts && !dtr) { + reset_state = DTR_NEGEDGE; + } +#endif +} + +#define RESET_DELAY 100000 +#if defined(BOOTLOADER_maple) +static void wait_reset(void) { + delay_us(RESET_DELAY); + nvic_sys_reset(); +} +#endif + +#define STACK_TOP 0x20000800 +#define EXC_RETURN 0xFFFFFFF9 +#define DEFAULT_CPSR 0x61000000 +static void rxHook(unsigned hook, void *ignored) { + /* FIXME this is mad buggy; we need a new reset sequence. E.g. NAK + * after each RX means you can't reset if any bytes are waiting. */ + if (reset_state == DTR_NEGEDGE) { + reset_state = DTR_LOW; + + if (usb_cdcacm_data_available() >= 4) { + // The magic reset sequence is "1EAF". +#if defined(BOOTLOADER_maple) + static const uint8 magic[4] = {'1', 'E', 'A', 'F'}; +#endif +#if defined(BOOTLOADER_robotis) + static const uint8 magic[4] = {'C', 'M', '9', 'X'}; +#endif + uint8 chkBuf[4]; + + // Peek at the waiting bytes, looking for reset sequence, + // bailing on mismatch. + usb_cdcacm_peek(chkBuf, 4); + for (unsigned i = 0; i < sizeof(magic); i++) { + if (chkBuf[i] != magic[i]) { + return; + } + } + +#if defined(BOOTLOADER_maple) + // Got the magic sequence -> reset, presumably into the bootloader. + // Return address is wait_reset, but we must set the thumb bit. + uintptr_t target = (uintptr_t)wait_reset | 0x1; + asm volatile("mov r0, %[stack_top] \n\t" // Reset stack + "mov sp, r0 \n\t" + "mov r0, #1 \n\t" + "mov r1, %[target_addr] \n\t" + "mov r2, %[cpsr] \n\t" + "push {r2} \n\t" // Fake xPSR + "push {r1} \n\t" // PC target addr + "push {r0} \n\t" // Fake LR + "push {r0} \n\t" // Fake R12 + "push {r0} \n\t" // Fake R3 + "push {r0} \n\t" // Fake R2 + "push {r0} \n\t" // Fake R1 + "push {r0} \n\t" // Fake R0 + "mov lr, %[exc_return] \n\t" + "bx lr" + : + : [stack_top] "r" (STACK_TOP), + [target_addr] "r" (target), + [exc_return] "r" (EXC_RETURN), + [cpsr] "r" (DEFAULT_CPSR) + : "r0", "r1", "r2"); +#endif + +#if defined(BOOTLOADER_robotis) + iwdg_init(IWDG_PRE_4, 10); +#endif + + /* Can't happen. */ + ASSERT_FAULT(0); + } + } +} + +#endif // BOARD_HAVE_SERIALUSB |