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tmk_keyboard/protocol/ibm4704.c
Jun Wako fdc38ef3f9 Squashed 'tmk_core/' changes from dc0e46e..57d27a8
57d27a8 Merge branch 'core_update_150924' into core
024abe3 core: Fix NKRO ifdef
7aa2d30 core: Fix for disabling NKRO in Boot protocol
95651fd core: Fix message print of debug command
c20cd29 lufa: Fix endpoint bank mode for ATMega32u2
82ac21f next_usb: Fix next_kbd_set_leds()
537d9c7 Change to KC_BOOTLOADER(KC_BTLD)
f2b3772 Add an assignable RESET key
fc99257 Fix parenthesis
e852582 Fix weak modifier clear in action macro
c2a6c5c core: Fix lufa suspend callback(#234)
fa548c5 usb_usb: Ignore error usage(0x01-03) report
513d95c usb_usb: Support locking key indicator LED
cd78802 core: Add keymap section ldscript for ATMega32U2
70c9abd Add description for non-US keys on keycode.h
538c192 lufa: Fix console flush #223
87628c9 Revert "Make action_for_key a weak symbol"
3c0a1ba Make action_for_key a weak symbol
6bb0d7d ibm4704_usb: Fix protocol handling
b6ef5cf Add keyboard_setup() and matrix_setup()
f4bb8b2 ibm4704_usb: Fix interrupt of clock(rising edge)
0c1fcc1 usb_usb: Change debug LED pin config
595710d Reduce code size of magic commands
6bed174 Add description of AVR bootloader and boot section
54c6a01 Merge commit 'f6d56675f9f981c5464f0ca7a1fbb0162154e8c5'
d18d42e Merge branch 'core-update2' into core
febec88 Add compile options '-fdata-sections'

git-subtree-dir: tmk_core
git-subtree-split: 57d27a8e39173a589b4abae74851f95c39940174
2015-09-24 12:29:11 +09:00

190 lines
4.6 KiB
C

/*
Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com>
*/
#include <stdbool.h>
#include <util/delay.h>
#include "debug.h"
#include "ring_buffer.h"
#include "ibm4704.h"
#define WAIT(stat, us, err) do { \
if (!wait_##stat(us)) { \
ibm4704_error = err; \
goto ERROR; \
} \
} while (0)
uint8_t ibm4704_error = 0;
void ibm4704_init(void)
{
inhibit(); // keep keyboard from sending
IBM4704_INT_INIT();
IBM4704_INT_ON();
idle(); // allow keyboard sending
}
/*
Host to Keyboard
----------------
Data bits are LSB first and Parity is odd. Clock has around 60us high and 30us low part.
____ __ __ __ __ __ __ __ __ __ ________
Clock \______/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
^ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ___
Data ____|__/ X____X____X____X____X____X____X____X____X____X \___
| Start 0 1 2 3 4 5 6 7 P Stop
Request by host
Start bit: can be long as 300-350us.
Request: Host pulls Clock line down to request to send a command.
Timing: After Request keyboard pull up Data and down Clock line to low for start bit.
After request host release Clock line once Data line becomes hi.
Host writes a bit while Clock is hi and Keyboard reads while low.
Stop bit: Host releases or pulls up Data line to hi after 9th clock and waits for keyboard pull down the line to lo.
*/
uint8_t ibm4704_send(uint8_t data)
{
bool parity = true; // odd parity
ibm4704_error = 0;
IBM4704_INT_OFF();
/* Request to send */
idle();
clock_lo();
/* wait for Start bit(Clock:lo/Data:hi) */
WAIT(data_hi, 300, 0x30);
/* Data bit */
for (uint8_t i = 0; i < 8; i++) {
WAIT(clock_hi, 100, 0x40+i);
if (data&(1<<i)) {
parity = !parity;
data_hi();
} else {
data_lo();
}
WAIT(clock_lo, 100, 0x48+i);
}
/* Parity bit */
WAIT(clock_hi, 100, 0x34);
if (parity) { data_hi(); } else { data_lo(); }
WAIT(clock_lo, 100, 0x35);
/* Stop bit */
WAIT(clock_hi, 100, 0x34);
data_hi();
/* End */
WAIT(data_lo, 100, 0x36);
idle();
IBM4704_INT_ON();
return 0;
ERROR:
idle();
if (ibm4704_error > 0x30) {
xprintf("S:%02X ", ibm4704_error);
}
IBM4704_INT_ON();
return -1;
}
/* wait forever to receive data */
uint8_t ibm4704_recv_response(void)
{
while (!rbuf_has_data()) {
_delay_ms(1);
}
return rbuf_dequeue();
}
uint8_t ibm4704_recv(void)
{
if (rbuf_has_data()) {
return rbuf_dequeue();
} else {
return -1;
}
}
/*
Keyboard to Host
----------------
Data bits are LSB first and Parity is odd. Clock has around 60us high and 30us low part.
____ __ __ __ __ __ __ __ __ __ _______
Clock \_____/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/
____ ____ ____ ____ ____ ____ ____ ____ ____ ____
Data ____/ X____X____X____X____X____X____X____X____X____X________
Start 0 1 2 3 4 5 6 7 P Stop
Start bit: can be long as 300-350us.
Inhibit: Pull Data line down to inhibit keyboard to send.
Timing: Host reads bit while Clock is hi.(rising edge)
Stop bit: Keyboard pulls down Data line to lo after 9th clock.
*/
ISR(IBM4704_INT_VECT)
{
static enum {
BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, PARITY, STOP
} state = BIT0;
// LSB first
static uint8_t data = 0;
// Odd parity
static uint8_t parity = false;
ibm4704_error = 0;
switch (state) {
case BIT0:
case BIT1:
case BIT2:
case BIT3:
case BIT4:
case BIT5:
case BIT6:
case BIT7:
data >>= 1;
if (data_in()) {
data |= 0x80;
parity = !parity;
}
break;
case PARITY:
if (data_in()) {
parity = !parity;
}
if (!parity)
goto ERROR;
break;
case STOP:
// Data:Low
WAIT(data_lo, 100, state);
rbuf_enqueue(data);
ibm4704_error = IBM4704_ERR_NONE;
goto DONE;
break;
default:
goto ERROR;
}
state++;
goto RETURN;
ERROR:
ibm4704_error = state;
while (ibm4704_send(0xFE)) _delay_ms(1); // resend
xprintf("R:%02X%02X\n", state, data);
DONE:
state = BIT0;
data = 0;
parity = false;
RETURN:
return;
}