diff options
Diffstat (limited to 'ps2.c')
| -rw-r--r-- | ps2.c | 181 |
1 files changed, 146 insertions, 35 deletions
@@ -1,5 +1,5 @@ /* -Copyright (c) 2010 Jun WAKO <wakojun@gmail.com> +Copyright (c) 2010,2011 Jun WAKO <wakojun@gmail.com> This software is licensed with a Modified BSD License. All of this is supposed to be Free Software, Open Source, DFSG-free, @@ -36,12 +36,13 @@ POSSIBILITY OF SUCH DAMAGE. */ #include <stdbool.h> #include <avr/io.h> +#include <avr/interrupt.h> #include <util/delay.h> #include "ps2.h" -#include "print.h" #include "debug.h" +static uint8_t recv_data(void); static inline void clock_lo(void); static inline void clock_hi(void); static inline bool clock_in(void); @@ -52,6 +53,8 @@ static inline uint16_t wait_clock_lo(uint16_t us); static inline uint16_t wait_clock_hi(uint16_t us); static inline uint16_t wait_data_lo(uint16_t us); static inline uint16_t wait_data_hi(uint16_t us); +static inline void idle(void); +static inline void inhibit(void); /* @@ -79,38 +82,38 @@ http://www.mcamafia.de/pdf/ibm_hitrc07.pdf } \ } while (0) -#define WAIT_NORETRY(stat, us, err) do { \ - if (!wait_##stat(us)) { \ - ps2_error = err; \ - return 0; \ - } \ -} while (0) - uint8_t ps2_error = PS2_ERR_NONE; void ps2_host_init(void) { - /* inhibit */ - clock_lo(); - data_hi(); +#ifdef PS2_INT_ENABLE + PS2_INT_ENABLE(); + idle(); +#else + inhibit(); +#endif } uint8_t ps2_host_send(uint8_t data) { - bool parity = true; + bool parity; +RETRY: + parity = true; ps2_error = 0; - /* request to send */ - clock_lo(); + /* terminate a transmission if we have */ + inhibit(); _delay_us(100); + /* start bit [1] */ data_lo(); clock_hi(); WAIT(clock_lo, 15000, 1); /* data [2-9] */ for (uint8_t i = 0; i < 8; i++) { + _delay_us(15); if (data&(1<<i)) { parity = !parity; data_hi(); @@ -121,44 +124,145 @@ uint8_t ps2_host_send(uint8_t data) WAIT(clock_lo, 50, 3); } /* parity [10] */ + _delay_us(15); if (parity) { data_hi(); } else { data_lo(); } WAIT(clock_hi, 50, 4); WAIT(clock_lo, 50, 5); /* stop bit [11] */ + _delay_us(15); data_hi(); /* ack [12] */ WAIT(data_lo, 50, 6); WAIT(clock_lo, 50, 7); + + /* wait for idle state */ WAIT(clock_hi, 50, 8); WAIT(data_hi, 50, 9); - /* inhibit device to send */ - clock_lo(); + uint8_t res = ps2_host_recv_response(); + if (res == 0xFE && data != 0xFE) + goto RETRY; - return 1; + inhibit(); + return res; ERROR: - /* inhibit device to send */ - data_hi(); - clock_lo(); + inhibit(); return 0; } -uint8_t ps2_host_recv(void) +/* receive data when host want else inhibit communication */ +uint8_t ps2_host_recv_response(void) { uint8_t data = 0; - bool parity = true; - ps2_error = 0; /* terminate a transmission if we have */ - clock_lo(); + inhibit(); _delay_us(100); /* release lines(idle state) */ - clock_hi(); - data_hi(); + idle(); + + /* wait start bit */ + wait_clock_lo(2000); + data = recv_data(); + + inhibit(); + return data; +} + +#ifndef PS2_INT_VECT +uint8_t ps2_host_recv(void) +{ + return ps2_host_recv_response(); +} +#else +/* ring buffer to store ps/2 key data */ +#define PBUF_SIZE 8 +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) +{ + if (!data) + return; + uint8_t next = (pbuf_head + 1) % PBUF_SIZE; + if (next != pbuf_tail) { + pbuf[pbuf_head] = data; + pbuf_head = next; + } else { + print("pbuf: full\n"); + } +} +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; +} + +/* get data received by interrupt */ +uint8_t ps2_host_recv(void) +{ + return pbuf_dequeue(); +} + +ISR(PS2_INT_VECT) +{ +PORTC = 0xFF; + /* interrupt means start bit comes */ + pbuf_enqueue(recv_data()); + + /* release lines(idle state) */ + idle(); + _delay_us(5); +PORTC = 0x00; +} +#endif + + +/* +static void ps2_reset(void) +{ + ps2_host_send(0xFF); + if (ps2_host_recv_response() == 0xFA) { + _delay_ms(1000); + ps2_host_recv_response(); + } +} +*/ + +/* send LED state to keyboard */ +void ps2_host_set_led(uint8_t led) +{ +#ifdef PS2_INT_DISABLE + PS2_INT_DISABLE(); +#endif + ps2_host_send(0xED); + ps2_host_recv_response(); + ps2_host_send(led); + ps2_host_recv_response(); +#ifdef PS2_INT_ENABLE + PS2_INT_ENABLE(); + idle(); +#endif +} + + +/* called after start bit comes */ +static uint8_t recv_data(void) +{ + uint8_t data = 0; + bool parity = true; + ps2_error = 0; /* start bit [1] */ - WAIT(clock_lo, 2000, 1); // How long should we wait? + WAIT(clock_lo, 1, 1); WAIT(data_lo, 1, 2); WAIT(clock_hi, 50, 3); @@ -185,18 +289,11 @@ uint8_t ps2_host_recv(void) WAIT(data_hi, 1, 9); WAIT(clock_hi, 50, 10); - /* inhibit device to send */ - clock_lo(); - return data; ERROR: - /* inhibit device to send */ - data_hi(); - clock_lo(); return 0; } - static inline void clock_lo() { PS2_CLOCK_PORT &= ~(1<<PS2_CLOCK_BIT); @@ -252,3 +349,17 @@ static inline uint16_t wait_data_hi(uint16_t us) while (!data_in() && us) { asm(""); _delay_us(1); us--; } return us; } + +/* idle state that device can send */ +static inline void idle(void) +{ + clock_hi(); + data_hi(); +} + +/* inhibit device to send */ +static inline void inhibit(void) +{ + clock_lo(); + data_hi(); +} |