uint8_t
rtc_read(uint32_t addr)
{
uint8_t data;
rtc_init();
rtc_ce(1);
rtc_dir(1);
rtc_do(1); /* Don't care */
rtc_do(1); /* R/#W = 1(READ) */
rtc_do(1); /* AD = 1 */
rtc_do(0); /* DT = 0 */
rtc_do(addr & 0x8); /* A3 */
rtc_do(addr & 0x4); /* A2 */
rtc_do(addr & 0x2); /* A1 */
rtc_do(addr & 0x1); /* A0 */
rtc_dir(0);
(void)rtc_di();
(void)rtc_di();
(void)rtc_di();
(void)rtc_di();
data = rtc_di(); /* D3 */
data <<= 1;
data |= rtc_di(); /* D2 */
data <<= 1;
data |= rtc_di(); /* D1 */
data <<= 1;
data |= rtc_di(); /* D0 */
rtc_ce(0);
return data & 0xf;
}
static int
rs5c313_read_reg(struct rs5c313_softc *sc, int addr)
{
int data;
/* output */
rtc_dir(sc, 1);
/* control */
rtc_do(sc, 1); /* ignored */
rtc_do(sc, 1); /* R/#W = 1(READ) */
rtc_do(sc, 1); /* AD = 1 */
rtc_do(sc, 0); /* DT = 0 */
/* address */
rtc_do(sc, addr & 0x8); /* A3 */
rtc_do(sc, addr & 0x4); /* A2 */
rtc_do(sc, addr & 0x2); /* A1 */
rtc_do(sc, addr & 0x1); /* A0 */
/* input */
rtc_dir(sc, 0);
/* ignore */
(void)rtc_di(sc);
(void)rtc_di(sc);
(void)rtc_di(sc);
(void)rtc_di(sc);
/* data */
data = rtc_di(sc); /* D3 */
data <<= 1;
data |= rtc_di(sc); /* D2 */
data <<= 1;
data |= rtc_di(sc); /* D1 */
data <<= 1;
data |= rtc_di(sc); /* D0 */
return data;
}