int pifacedigital_open(uint8_t hw_addr)
{
if ((mcp23s17_fd = pifacedigital_open_noinit(hw_addr)) < 0)
{
fprintf(stderr,
"pifacedigital_open: ERROR Could not open MCP23S17 device.");
return -1;
}
// set up config register
const uint8_t ioconfig = BANK_OFF | \
INT_MIRROR_OFF | \
SEQOP_OFF | \
DISSLW_OFF | \
HAEN_ON | \
ODR_OFF | \
INTPOL_LOW;
mcp23s17_write_reg(ioconfig, IOCON, hw_addr, mcp23s17_fd);
// I/O direction
mcp23s17_write_reg(0x00, IODIRA, hw_addr, mcp23s17_fd);
mcp23s17_write_reg(0xff, IODIRB, hw_addr, mcp23s17_fd);
// GPIOB pull ups
mcp23s17_write_reg(0xff, GPPUB, hw_addr, mcp23s17_fd);
// enable interrupts
mcp23s17_write_reg(0xff, GPINTENB, hw_addr, mcp23s17_fd);
return mcp23s17_fd; // returns the fd, for advanced users.
}
void mcp23s17_write_bit(uint8_t data,
uint8_t bit_num,
uint8_t reg,
uint8_t hw_addr,
int fd)
{
uint8_t reg_data = mcp23s17_read_reg(reg, hw_addr, fd);
if (data) {
reg_data |= 1 << bit_num; // set
} else {
reg_data &= 0xff ^ (1 << bit_num); // clear
}
return mcp23s17_write_reg(reg_data, reg, hw_addr, fd);
}
void pifacedigital_close(uint8_t hw_addr)
{
if (pfd_count <= 0)
return;
pfd_count--;
// disable interrupts if enabled
const uint8_t intenb = mcp23s17_read_reg(GPINTENB, hw_addr, mcp23s17_fd);
if (intenb)
{
mcp23s17_write_reg(0, GPINTENB, hw_addr, mcp23s17_fd);
// now do some other interrupt stuff...
// TODO
}
// if no more PiFace Digital's, close the fd
if (pfd_count <= 0)
{
pfd_count = 0;
close(mcp23s17_fd);
}
}
void pifacedigital_write_reg(uint8_t data, uint8_t reg, uint8_t hw_addr)
{
mcp23s17_write_reg(data, reg, hw_addr, mcp23s17_fd);
}