From e0d688d4c8040302fcacb735350c95fe6be4dbde Mon Sep 17 00:00:00 2001 From: Joel Challis Date: Thu, 7 Oct 2021 23:14:26 +0100 Subject: Move converter specific tmk_core protocols (#14743) --- keyboards/converter/xt_usb/xt_interrupt.c | 166 ++++++++++++++++++++++++++++++ 1 file changed, 166 insertions(+) create mode 100644 keyboards/converter/xt_usb/xt_interrupt.c (limited to 'keyboards/converter/xt_usb/xt_interrupt.c') diff --git a/keyboards/converter/xt_usb/xt_interrupt.c b/keyboards/converter/xt_usb/xt_interrupt.c new file mode 100644 index 0000000000..ba9d71848f --- /dev/null +++ b/keyboards/converter/xt_usb/xt_interrupt.c @@ -0,0 +1,166 @@ +/* +Copyright 2018 Jun WAKO +Copyright 2016 Ethan Apodaca + +This software is licensed with a Modified BSD License. +All of this is supposed to be Free Software, Open Source, DFSG-free, +GPL-compatible, and OK to use in both free and proprietary applications. +Additions and corrections to this file are welcome. + + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + +* Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + +* Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + +* Neither the name of the copyright holders nor the names of + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. +*/ + +#include +#include +#include "xt.h" +#include "wait.h" +#include "debug.h" + +static inline uint8_t pbuf_dequeue(void); +static inline void pbuf_enqueue(uint8_t data); +static inline bool pbuf_has_data(void); +static inline void pbuf_clear(void); + +void xt_host_init(void) { + XT_INT_INIT(); + XT_INT_OFF(); + + /* hard reset */ +#ifdef XT_RESET + XT_RESET(); +#endif + + /* soft reset: pull clock line down for 20ms */ + XT_DATA_LO(); + XT_CLOCK_LO(); + wait_ms(20); + + /* input mode with pullup */ + XT_CLOCK_IN(); + XT_DATA_IN(); + + XT_INT_ON(); +} + +/* get data received by interrupt */ +uint8_t xt_host_recv(void) { + if (pbuf_has_data()) { + return pbuf_dequeue(); + } else { + return 0; + } +} + +ISR(XT_INT_VECT) { + /* + * XT signal format consits of 10 or 9 clocks and sends start bits and 8-bit data, + * which should be read on falling edge of clock. + * + * start(0), start(1), bit0, bit1, bit2, bit3, bit4, bit5, bit6, bit7 + * + * Original IBM XT keyboard sends start(0) bit while some of clones don't. + * Start(0) bit is read as low on data line while start(1) as high. + * + * https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-XT-Keyboard-Protocol + */ + static enum { START, BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7 } state = START; + static uint8_t data = 0; + + uint8_t dbit = XT_DATA_READ(); + + // This is needed if using PCINT which can be called on both falling and rising edge + // if (XT_CLOCK_READ()) return; + + switch (state) { + case START: + // ignore start(0) bit + if (!dbit) return; + break; + case BIT0 ... BIT7: + data >>= 1; + if (dbit) data |= 0x80; + break; + } + if (state++ == BIT7) { + pbuf_enqueue(data); + state = START; + data = 0; + } + return; +} + +/*-------------------------------------------------------------------- + * Ring buffer to store scan codes from keyboard + *------------------------------------------------------------------*/ +#define PBUF_SIZE 32 +static uint8_t pbuf[PBUF_SIZE]; +static uint8_t pbuf_head = 0; +static uint8_t pbuf_tail = 0; + +static inline void pbuf_enqueue(uint8_t data) { + uint8_t sreg = SREG; + cli(); + uint8_t next = (pbuf_head + 1) % PBUF_SIZE; + if (next != pbuf_tail) { + pbuf[pbuf_head] = data; + pbuf_head = next; + } else { + dprintf("pbuf: full\n"); + } + SREG = sreg; +} + +static inline uint8_t pbuf_dequeue(void) { + uint8_t val = 0; + + uint8_t sreg = SREG; + cli(); + if (pbuf_head != pbuf_tail) { + val = pbuf[pbuf_tail]; + pbuf_tail = (pbuf_tail + 1) % PBUF_SIZE; + } + SREG = sreg; + + return val; +} + +static inline bool pbuf_has_data(void) { + uint8_t sreg = SREG; + cli(); + bool has_data = (pbuf_head != pbuf_tail); + SREG = sreg; + return has_data; +} + +static inline void pbuf_clear(void) { + uint8_t sreg = SREG; + cli(); + pbuf_head = pbuf_tail = 0; + SREG = sreg; +} -- cgit v1.2.3