|
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495 |
- /*
- Copyright 2016 Kai Ryu <[email protected]>
-
- 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 2 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 <http://www.gnu.org/licenses/>.
- */
-
- #include <avr/interrupt.h>
- #include <avr/wdt.h>
- #include <util/delay.h>
- #include "i2cmaster.h"
- #include "i2c_wrapper.h"
- #include "debug.h"
-
- #define wdt_intr_enable(value) \
- __asm__ __volatile__ ( \
- "in __tmp_reg__,__SREG__" "\n\t" \
- "cli" "\n\t" \
- "wdr" "\n\t" \
- "sts %0,%1" "\n\t" \
- "out __SREG__,__tmp_reg__" "\n\t" \
- "sts %0,%2" "\n\t" \
- : /* no outputs */ \
- : "M" (_SFR_MEM_ADDR(_WD_CONTROL_REG)), \
- "r" (_BV(_WD_CHANGE_BIT) | _BV(WDE)), \
- "r" ((uint8_t) ((value & 0x08 ? _WD_PS3_MASK : 0x00) | \
- _BV(WDIE) | (value & 0x07)) ) \
- : "r0" \
- )
-
- #define SCL_CLOCK 400000L
- #define SCL_DURATION (1000000L/SCL_CLOCK)/2
-
- static uint8_t i2c_wdt_enabled = 0;
-
- extern uint8_t i2c_force_stop;
-
- static void wdt_init(void);
-
- void i2c_wrapper_init(void)
- {
- /* init i2c */
- i2c_init();
-
- /* init watch dog */
- wdt_init();
- }
-
- void i2c_wrapper_task(void)
- {
- /* reset watch dog counter */
- wdt_reset();
- }
-
- void wdt_init(void)
- {
- cli();
- wdt_reset();
- wdt_intr_enable(WDTO_2S);
- sei();
- }
-
- ISR(WDT_vect)
- {
- xprintf("i2c timeout\n");
-
- /* let slave to release SDA */
- TWCR = 0;
- DDRD |= (1<<PD0);
- DDRD &= ~(1<<PD1);
- if (!(PIND & (1<<PD1))) {
- for (uint8_t i = 0; i < 9; i++) {
- PORTD &= ~(1<<PD0);
- _delay_us(SCL_DURATION);
- PORTD |= (1<<PD0);
- _delay_us(SCL_DURATION);
- }
- }
-
- /* send stop condition */
- TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
-
- /* escape from loop */
- i2c_force_stop = 1;
- }
|