int uwire_xfer(int cs, int bitlen, const void *dout, void *din)
{
uint16_t tmp = 0;
if (bitlen <= 0 || bitlen > 16)
return -1;
if (cs < 0 || cs > 4)
return -1;
/* FIXME uwire_init always selects CS0 for now */
dbg("uwire_xfer(dev_idx=%u, bitlen=%u\n", cs, bitlen);
/* select the chip */
putreg16(UWIRE_CSR_IDX(0) | UWIRE_CSR_CS_CMD, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
if (dout)
{
if (bitlen <= 8)
tmp = *(uint8_t *)dout;
else if (bitlen <= 16)
tmp = *(uint16_t *)dout;
tmp <<= 16 - bitlen; /* align to MSB */
putreg16(tmp, UWIRE_REG(REG_DATA));
dbg(", data_out=0x%04hx", tmp);
}
tmp = (dout ? UWIRE_CSR_BITS_WR(bitlen) : 0) |
(din ? UWIRE_CSR_BITS_RD(bitlen) : 0) |
UWIRE_CSR_START;
putreg16(tmp, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
if (din)
{
_uwire_wait(UWIRE_CSR_RDRB, UWIRE_CSR_RDRB);
tmp = getreg16(UWIRE_REG(REG_DATA));
dbg(", data_in=0x%08x", tmp);
if (bitlen <= 8)
*(uint8_t *)din = tmp & 0xff;
else if (bitlen <= 16)
*(uint16_t *)din = tmp & 0xffff;
}
/* unselect the chip */
putreg16(UWIRE_CSR_IDX(0) | 0, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
dbg(")\n");
return 0;
}
void uwire_init(void)
{
writew(UWIRE_SR3_CLK_EN | UWIRE_SR3_CLK_DIV2, UWIRE_REG(REG_SR3));
/* FIXME only init CS0 for now */
writew(((UWIRE_CSn_CS_LVL | UWIRE_CSn_FRQ_DIV2) << UWIRE_CSn_SHIFT(0)),
UWIRE_REG(UWIRE_CSn_REG(0)));
writew(UWIRE_CSR_IDX(0) | UWIRE_CSR_CS_CMD, UWIRE_REG(REG_CSR));
_uwire_wait(UWIRE_CSR_CSRB, 0);
}
