diff options
Diffstat (limited to 'fpm.c')
| -rw-r--r-- | fpm.c | 181 |
1 files changed, 181 insertions, 0 deletions
@@ -0,0 +1,181 @@ +#include <avr/io.h> +#include <util/delay.h> +#include <util/setbaud.h> + +#include "fpm.h" + +#define MAXPDLEN 64 +#define RST_DELAY_MS 500 + +#define PWD 0x00 + +#define CMD 0x01 + +#define OK 0x00 + +static uint8_t start_code[] = { 0xEF, 0x01 }; +static uint8_t addr[] = { 0xFF, 0xFF, 0xFF, 0xFF }; + +static inline uint8_t read(void) +{ + while (!(UCSR0A & (1 << RXC0))) + ; + return UDR0; +} + +static inline void write(uint8_t c) +{ + while (!(UCSR0A & (1 << UDRE0))) + ; + UDR0 = c; +} + +static inline void write_bulk(uint8_t *data, uint16_t n) +{ + int i; + + for (i = 0; i < n; i++) + write(data[i]); +} + +static inline void send(uint8_t pktid, uint8_t *data, uint8_t n) +{ + int i; + uint16_t pktlen, sum; + + write_bulk(start_code, 2); + write_bulk(addr, 4); + write(pktid); + + pktlen = n + 2; + write((uint8_t)(pktlen >> 8)); + write((uint8_t)pktlen); + + sum = (pktlen >> 8) + (pktlen & 0xFF) + pktid; + for (i = 0; i < n; i++) { + write(data[i]); + sum += data[i]; + } + + write((uint8_t)(sum >> 8)); + write((uint8_t)sum); +} + +static inline void recv(uint8_t buf[MAXPDLEN], uint16_t *n) +{ + int i; + uint16_t len; + uint8_t byte; + + i = 0, len = 0; + + for (;;) { + byte = read(); + switch (i) { + case 0: + if (byte != start_code[0]) + continue; + break; + case 1: + if (byte != start_code[1]) + goto bad_pkt; + break; + case 2: + case 3: + case 4: + case 5: + // toss the address + break; + case 6: + // toss the packet id + break; + case 7: + len = (uint16_t)byte << 8; + break; + case 8: + len |= byte; + break; + default: + if ((i - 9) < MAXPDLEN) { + buf[i - 9] = byte; + if ((i - 8) == len) { + *n = len; + return; + } + } else { + goto bad_pkt; + } + break; + } + i++; + } + +bad_pkt: + *n = 0; + return; +} + +static inline uint8_t check_pwd(void) +{ + unsigned int n; + uint8_t buf[MAXPDLEN]; + + buf[0] = 0x13; + buf[1] = (uint8_t)((uint32_t)PWD >> 24); + buf[2] = (uint8_t)((uint32_t)PWD >> 16); + buf[3] = (uint8_t)((uint32_t)PWD >> 8); + buf[4] = (uint8_t)((uint32_t)PWD & 0xFF); + + send(CMD, buf, 5); + + n = 0; + recv(buf, &n); + return buf[0] == OK; +} + +uint8_t fpm_init(void) +{ + UBRR0H = UBRRH_VALUE; + UBRR0L = UBRRL_VALUE; +#if USE_2X + UCSR0A |= (1 << U2X0); +#else + UCSR0A &= ~(1 << U2X0); +#endif + UCSR0B = (1 << TXEN0) | (1 << RXEN0); + UCSR0C = (1 << UCSZ01) | (1 << UCSZ00); + + _delay_ms(RST_DELAY_MS); + + return check_pwd(); +} + +uint8_t fpm_get_config(struct fpm_config *cfg) +{ + uint16_t n; + uint8_t buf[MAXPDLEN]; + + buf[0] = 0x0F; + send(CMD, buf, 1); + + n = 0; + recv(buf, &n); + + if (buf[0] == OK && n >= 17) { + cfg->status = ((uint16_t)buf[1] << 8) | buf[2]; + cfg->sysid = ((uint16_t)buf[3] << 8) | buf[4]; + cfg->cap = ((uint16_t)buf[5] << 8) | buf[6]; + cfg->sec_level = ((uint16_t)buf[7] << 8) | buf[8]; + cfg->addr[0] = buf[9]; + cfg->addr[1] = buf[10]; + cfg->addr[2] = buf[11]; + cfg->addr[3] = buf[12]; + cfg->pkt_size = ((uint16_t)buf[13] << 8) | buf[14]; + cfg->pkt_size = 1 << (cfg->pkt_size + 5); + cfg->baud = (((uint16_t)buf[15] << 8) | buf[16]); + + return 1; + } + return 0; +} + |