// to use only with values up to a couple seconds
void sleep_ms(int millisec) {
sleep_ns(millisec * EXP_6);
}
int bitbang_io(const bitbang_handle_st *hdl, bitbang_io_st *io)
{
int rc = 0;
uint32_t clk = hdl->bbh_half_clk;
const struct {
bitbang_pin_value_en value;
bitbang_clk_edge_en edge;
} clks[] = {
{BITBANG_PIN_HIGH, BITBANG_CLK_EDGE_FALLING},
{BITBANG_PIN_LOW, BITBANG_CLK_EDGE_RISING},
};
int clk_idx;
int n_clk = 0;
int n_bits = 0;
const uint8_t *dout = io->bbio_dout;
uint8_t *din = io->bbio_din;
int bit_pos = 7;
bitbang_pin_func pin_f = hdl->bbh_init.bbi_pin_f;
void *context = hdl->bbh_init.bbi_context;
if ((io->bbio_in_bits == 0 && io->bbio_din)
|| (io->bbio_in_bits > 0 && !io->bbio_din)) {
rc = EINVAL;
LOG_ERR(rc, "Incorrect in bits and in buffer");
goto out;
}
if ((io->bbio_out_bits == 0 && io->bbio_dout)
|| (io->bbio_out_bits > 0 && !io->bbio_dout)) {
rc = EINVAL;
LOG_ERR(rc, "Incorrect out bits and out buffer");
goto out;
}
if (io->bbio_in_bits == 0 && io->bbio_out_bits == 0) {
rc = EINVAL;
LOG_ERR(rc, "Both in and out bits are 0");
goto out;
}
if (hdl->bbh_init.bbi_clk_start == BITBANG_PIN_HIGH) {
clk_idx = 0;
} else {
clk_idx = 1;
}
/* set the CLK pin start position */
pin_f(BITBANG_CLK_PIN, clks[clk_idx].value, context);
/* clear the first byte of din */
if (din && io->bbio_in_bits) {
memset(din, 0, (io->bbio_in_bits + 7) / 8);
}
do {
if ((rc = sleep_ns(clk))) {
goto out;
}
/* output first */
if (hdl->bbh_init.bbi_data_out == clks[clk_idx].edge) {
if (dout && n_bits < io->bbio_out_bits) {
pin_f(BITBANG_DATA_OUT, (*dout >> bit_pos) & 0x1, context);
}
}
/* then, input */
if (hdl->bbh_init.bbi_data_in == clks[clk_idx].edge) {
if (din && n_bits < io->bbio_in_bits) {
*din |= (pin_f(BITBANG_DATA_IN, 0, context) & 0x1) << bit_pos;
}
}
if (++n_clk % 2 == 0) {
/* one bit for every 2 half clks */
n_bits ++;
if (bit_pos == 0) {
if (dout) {
dout++;
}
if (din) {
din++;
}
bit_pos = 7;
} else {
bit_pos --;
}
}
clk_idx = 1 - clk_idx;
pin_f(BITBANG_CLK_PIN, clks[clk_idx].value, context);
} while (n_bits < MAX(io->bbio_in_bits, io->bbio_out_bits));
void sleep_us(int microsec) {
sleep_ns(microsec * EXP_3);
}
static void sleep_ms(int msecs) { sleep_ns(msecs*1000000); }
