diff options
Diffstat (limited to 'drivers/gpio/mcp23018.c')
| -rw-r--r-- | drivers/gpio/mcp23018.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/gpio/mcp23018.c b/drivers/gpio/mcp23018.c index 41cbfe087e..b4fbf296f8 100644 --- a/drivers/gpio/mcp23018.c +++ b/drivers/gpio/mcp23018.c @@ -18,14 +18,20 @@ enum { CMD_GPIOB = 0x13, }; -void mcp23018_init(uint8_t addr) { +bool mcp23018_init(uint8_t slave_addr) { static uint8_t s_init = 0; - if (!s_init) { + uint8_t addr = SLAVE_TO_ADDR(slave_addr); + if (0 == s_init) { i2c_init(); - wait_ms(1000); + wait_ms(100); - s_init = 1; + // probe that the expander is actually connected by reading from it + uint8_t data = 0; + if (I2C_STATUS_SUCCESS == i2c_readReg(addr, 0, &data, sizeof(data), 150)) { + s_init = 1; + } } + return (s_init > 0); } bool mcp23018_set_config(uint8_t slave_addr, mcp23018_port_t port, uint8_t conf) { |