OpenRGB/i2c_smbus/i2c_smbus_nvapi.cpp

102 lines
2.6 KiB
C++

/*-----------------------------------------*\
| i2c_smbus_nvapi.cpp |
| |
| NVidia NvAPI I2C driver for Windows |
| |
| Adam Honse (CalcProgrammer1) 2/21/2020 |
\*-----------------------------------------*/
#include "i2c_smbus_nvapi.h"
i2c_smbus_nvapi::i2c_smbus_nvapi(NV_PHYSICAL_GPU_HANDLE handle)
{
this->handle = handle;
}
s32 i2c_smbus_nvapi::i2c_smbus_xfer(u8 addr, char read_write, u8 command, int size, i2c_smbus_data* data)
{
NV_STATUS ret;
unsigned int unknown = 0;
NV_I2C_INFO_V3 i2c_data;
uint8_t data_buf[8];
uint8_t chip_addr;
// Set up chip register address to command, one byte in length
chip_addr = command;
i2c_data.i2c_reg_address = &chip_addr;
i2c_data.reg_addr_size = 1;
// Set up data buffer, zero bytes in length
i2c_data.data = data_buf;
i2c_data.size = 0;
// Always use GPU port 1 - this is where RGB controllers are attached
i2c_data.is_ddc_port = 0;
i2c_data.port_id = 1;
i2c_data.is_port_id_set = 1;
// Use default speed
i2c_data.i2c_speed = 0xFFFF;
i2c_data.i2c_speed_khz = NV_I2C_SPEED::NVAPI_I2C_SPEED_DEFAULT;
// Load device address
i2c_data.i2c_dev_address = (addr << 1) | read_write;
switch (size)
{
case I2C_SMBUS_QUICK:
// This is not supported by the driver it seems
i2c_data.reg_addr_size = 0;
i2c_data.size = 0;
break;
case I2C_SMBUS_BYTE:
// One byte of data with no register address
i2c_data.reg_addr_size = 0;
data_buf[0] = command;
i2c_data.size = 1;
break;
case I2C_SMBUS_BYTE_DATA:
// One byte of data with one byte of register address
data_buf[0] = data->byte;
i2c_data.size = 1;
break;
case I2C_SMBUS_WORD_DATA:
// One word of data with one byte of register address
data_buf[0] = (data->word & 0x00ff);
data_buf[1] = (data->word & 0xff00) >> 8;
i2c_data.size = 2;
break;
// Not supported
case I2C_SMBUS_BLOCK_DATA:
return -1;
break;
default:
return -1;
}
// Perform read or write
if(read_write == I2C_SMBUS_WRITE)
{
ret = NvAPI_I2CWriteEx(handle, &i2c_data, &unknown);
}
else
{
ret = NvAPI_I2CReadEx(handle, &i2c_data, &unknown);
if(i2c_data.size == 1)
{
data->byte = i2c_data.data[0];
}
else
{
data->word = (i2c_data.data[0] | (i2c_data.data[1] << 8));
}
}
return(ret);
}