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authortmk <nobody@nowhere>2014-02-09 02:42:17 +0900
committertmk <nobody@nowhere>2014-02-09 02:42:17 +0900
commitebe951a445b5d774542731d6165a9c5cd56beb2b (patch)
treef907b82fa3cbeeea4dc8cea96f83ee0d298372d5 /protocol/ibm4704.c
parentcb3a547ebff8e09401c7d635ed24585a7521bb19 (diff)
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Add Initial files of 4704_usb
Diffstat (limited to 'protocol/ibm4704.c')
-rw-r--r--protocol/ibm4704.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/protocol/ibm4704.c b/protocol/ibm4704.c
new file mode 100644
index 000000000..26441ed52
--- /dev/null
+++ b/protocol/ibm4704.c
@@ -0,0 +1,150 @@
+/*
+Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com>
+*/
+#include <stdbool.h>
+#include <util/delay.h>
+#include "debug.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)
+{
+ // POR
+ //_delay_ms(2500);
+ //while ( 0xA3 != ibm4704_recv() ) ;
+
+ inhibit();
+ DDRD |= 1<<3;
+ PORTD &= ~(1<<3);
+}
+
+uint8_t ibm4704_send(uint8_t data)
+{
+ bool parity = true; // odd parity
+ ibm4704_error = 0;
+
+ /* Request to send */
+ idle();
+ clock_lo();
+PIND |= 1<<3;
+
+ /* 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, 0x31);
+ //_delay_us(5);
+PIND |= 1<<3;
+ if (data&(1<<i)) {
+ parity = !parity;
+ data_hi();
+ } else {
+ data_lo();
+ }
+ WAIT(clock_lo, 100, 0x32);
+ }
+
+ /* Parity bit */
+ WAIT(clock_hi, 100, 4);
+PIND |= 1<<3;
+ if (parity) { data_hi(); } else { data_lo(); }
+ WAIT(clock_lo, 100, 5);
+
+ /* Stop bit */
+ WAIT(clock_hi, 100, 4);
+ data_hi();
+
+ /* End */
+ WAIT(data_lo, 100, 6);
+
+ inhibit();
+ _delay_us(200); // wait to recover clock to hi
+ return 0;
+ERROR:
+ inhibit();
+xprintf("x%02X ", ibm4704_error);
+ _delay_us(200); // wait to recover clock to hi
+ return -1;
+}
+
+/* receive data when host want else inhibit communication */
+uint8_t ibm4704_recv_response(void)
+{
+ // 250 * 100us(wait start bit in ibm4704_recv)
+ uint8_t data = 0;
+ uint8_t try = 250;
+ do {
+ data = ibm4704_recv();
+ } while (try-- && ibm4704_error);
+ return data;
+}
+
+/*
+Keyboard to Host:
+Clock ~~~~___~~_~~_~~_~~_~~_~~_~~_~~_~~_~~~~~~~~ H:60us/L:30us
+
+Data ____~~X==X==X==X==X==X==X==X==X==X________
+ | 0 1 2 3 4 5 6 7 P(odd)
+ | LSB MSB
+ Start bit(80us)
+*/
+uint8_t ibm4704_recv(void)
+{
+ uint8_t data = 0;
+ bool parity = true; // odd parity
+ ibm4704_error = IBM4704_ERR_NONE;
+
+ idle();
+ _delay_us(5); // wait for line settles
+
+ /* start bit */
+ WAIT(clock_lo, 100, 1); // wait for keyboard to send
+ WAIT(data_hi, 100, 2); // can be delayed that long
+
+ WAIT(clock_hi, 100, 3); // first rising edge which can take longer
+ /* data */
+ for (uint8_t i = 0; i < 8; i++) {
+ WAIT(clock_hi, 100, 0x20+i);
+ //_delay_us(5);
+ if (data_in()) {
+ parity = !parity;
+ data |= (1<<i);
+ }
+ WAIT(clock_lo, 150, 0x28+i);
+ }
+
+ /* parity */
+ WAIT(clock_hi, 100, 7);
+ if (data_in() != parity) {
+ ibm4704_error = IBM4704_ERR_PARITY;
+ goto ERROR;
+ }
+ WAIT(clock_lo, 150, 8);
+
+ /* stop bit */
+ WAIT(clock_hi, 100, 9);
+ WAIT(data_lo, 1, 9);
+
+ inhibit();
+ _delay_us(200); // wait to recover clock to hi
+ return data;
+ERROR:
+ if (ibm4704_error > 2) {
+ xprintf("x%02X ", ibm4704_error);
+ }
+ inhibit();
+ _delay_us(200); // wait to recover clock to hi
+ return -1;
+}