pimoroni-pico/common/pimoroni_i2c.cpp

105 wiersze
3.8 KiB
C++

#include "pimoroni_common.hpp"
#include "pimoroni_i2c.hpp"
namespace pimoroni {
void I2C::init() {
i2c = pin_to_inst(sda);
// TODO call pin_to_inst on sda and scl, and verify they are a valid i2c pin pair
// TODO maybe also fall back to PIO i2c for non-standard pin combinations
// Since it's easy to leave the I2C in a bad state when experimenting in the MicroPython REPL
// this loop will find any I2C pins relevant to the current instance and reset them.
for(auto pin = 0u; pin < 30; pin++) {
if(pin_to_inst(pin) == i2c && gpio_get_function(pin) == GPIO_FUNC_I2C) {
gpio_disable_pulls(pin);
gpio_set_function(pin, GPIO_FUNC_NULL);
}
}
i2c_init(i2c, baudrate);
gpio_set_function(sda, GPIO_FUNC_I2C); gpio_pull_up(sda);
gpio_set_function(scl, GPIO_FUNC_I2C); gpio_pull_up(scl);
}
i2c_inst_t* I2C::pin_to_inst(uint pin) {
return ((pin >> 1) & 0b1) ? i2c1 : i2c0;
}
/* Basic wrappers for devices using i2c functions directly */
int I2C::write_blocking(uint8_t addr, const uint8_t *src, size_t len, bool nostop) {
return i2c_write_blocking(i2c, addr, src, len, nostop);
}
int I2C::read_blocking(uint8_t addr, uint8_t *dst, size_t len, bool nostop) {
return i2c_read_blocking(i2c, addr, dst, len, nostop);
}
/* Convenience functions for various common i2c operations */
void I2C::reg_write_uint8(uint8_t address, uint8_t reg, uint8_t value) {
uint8_t buffer[2] = {reg, value};
i2c_write_blocking(i2c, address, buffer, 2, false);
}
uint8_t I2C::reg_read_uint8(uint8_t address, uint8_t reg) {
uint8_t value;
i2c_write_blocking(i2c, address, &reg, 1, false);
i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(uint8_t), false);
return value;
}
uint16_t I2C::reg_read_uint16(uint8_t address, uint8_t reg) {
uint16_t value;
i2c_write_blocking(i2c, address, &reg, 1, true);
i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(uint16_t), false);
return value;
}
uint32_t I2C::reg_read_uint32(uint8_t address, uint8_t reg) {
uint32_t value;
i2c_write_blocking(i2c, address, &reg, 1, true);
i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(uint32_t), false);
return value;
}
int16_t I2C::reg_read_int16(uint8_t address, uint8_t reg) {
int16_t value;
i2c_write_blocking(i2c, address, &reg, 1, true);
i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(int16_t), false);
return value;
}
int I2C::write_bytes(uint8_t address, uint8_t reg, uint8_t *buf, int len) {
uint8_t buffer[len + 1];
buffer[0] = reg;
for(int x = 0; x < len; x++) {
buffer[x + 1] = buf[x];
}
return i2c_write_blocking(i2c, address, buffer, len + 1, false);
};
int I2C::read_bytes(uint8_t address, uint8_t reg, uint8_t *buf, int len) {
i2c_write_blocking(i2c, address, &reg, 1, true);
i2c_read_blocking(i2c, address, buf, len, false);
return len;
};
uint8_t I2C::get_bits(uint8_t address, uint8_t reg, uint8_t shift, uint8_t mask) {
uint8_t value;
read_bytes(address, reg, &value, 1);
return value & (mask << shift);
}
void I2C::set_bits(uint8_t address, uint8_t reg, uint8_t shift, uint8_t mask) {
uint8_t value;
read_bytes(address, reg, &value, 1);
value |= mask << shift;
write_bytes(address, reg, &value, 1);
}
void I2C::clear_bits(uint8_t address, uint8_t reg, uint8_t shift, uint8_t mask) {
uint8_t value;
read_bytes(address, reg, &value, 1);
value &= ~(mask << shift);
write_bytes(address, reg, &value, 1);
}
}