static int ft260_smbus_xfer()

in hid-ft260.c [596:702]

• 98 lines of code
• 18 McCabe index (conditional complexity)

static int ft260_smbus_xfer(struct i2c_adapter *adapter, u16 addr, u16 flags,
			    char read_write, u8 cmd, int size,
			    union i2c_smbus_data *data)
{
	int ret;
	struct ft260_device *dev = i2c_get_adapdata(adapter);
	struct hid_device *hdev = dev->hdev;

	ft260_dbg("smbus size %d\n", size);

	mutex_lock(&dev->lock);

	ret = hid_hw_power(hdev, PM_HINT_FULLON);
	if (ret < 0) {
		hid_err(hdev, "power management error: %d\n", ret);
		mutex_unlock(&dev->lock);
		return ret;
	}

	switch (size) {
	case I2C_SMBUS_QUICK:
		if (read_write == I2C_SMBUS_READ)
			ret = ft260_i2c_read(dev, addr, &data->byte, 0,
					     FT260_FLAG_START_STOP);
		else
			ret = ft260_smbus_write(dev, addr, cmd, NULL, 0,
						FT260_FLAG_START_STOP);
		break;
	case I2C_SMBUS_BYTE:
		if (read_write == I2C_SMBUS_READ)
			ret = ft260_i2c_read(dev, addr, &data->byte, 1,
					     FT260_FLAG_START_STOP);
		else
			ret = ft260_smbus_write(dev, addr, cmd, NULL, 0,
						FT260_FLAG_START_STOP);
		break;
	case I2C_SMBUS_BYTE_DATA:
		if (read_write == I2C_SMBUS_READ) {
			ret = ft260_smbus_write(dev, addr, cmd, NULL, 0,
						FT260_FLAG_START);
			if (ret)
				goto smbus_exit;

			ret = ft260_i2c_read(dev, addr, &data->byte, 1,
					     FT260_FLAG_START_STOP_REPEATED);
		} else {
			ret = ft260_smbus_write(dev, addr, cmd, &data->byte, 1,
						FT260_FLAG_START_STOP);
		}
		break;
	case I2C_SMBUS_WORD_DATA:
		if (read_write == I2C_SMBUS_READ) {
			ret = ft260_smbus_write(dev, addr, cmd, NULL, 0,
						FT260_FLAG_START);
			if (ret)
				goto smbus_exit;

			ret = ft260_i2c_read(dev, addr, (u8 *)&data->word, 2,
					     FT260_FLAG_START_STOP_REPEATED);
		} else {
			ret = ft260_smbus_write(dev, addr, cmd,
						(u8 *)&data->word, 2,
						FT260_FLAG_START_STOP);
		}
		break;
	case I2C_SMBUS_BLOCK_DATA:
		if (read_write == I2C_SMBUS_READ) {
			ret = ft260_smbus_write(dev, addr, cmd, NULL, 0,
						FT260_FLAG_START);
			if (ret)
				goto smbus_exit;

			ret = ft260_i2c_read(dev, addr, data->block,
					     data->block[0] + 1,
					     FT260_FLAG_START_STOP_REPEATED);
		} else {
			ret = ft260_smbus_write(dev, addr, cmd, data->block,
						data->block[0] + 1,
						FT260_FLAG_START_STOP);
		}
		break;
	case I2C_SMBUS_I2C_BLOCK_DATA:
		if (read_write == I2C_SMBUS_READ) {
			ret = ft260_smbus_write(dev, addr, cmd, NULL, 0,
						FT260_FLAG_START);
			if (ret)
				goto smbus_exit;

			ret = ft260_i2c_read(dev, addr, data->block + 1,
					     data->block[0],
					     FT260_FLAG_START_STOP_REPEATED);
		} else {
			ret = ft260_smbus_write(dev, addr, cmd, data->block + 1,
						data->block[0],
						FT260_FLAG_START_STOP);
		}
		break;
	default:
		hid_err(hdev, "unsupported smbus transaction size %d\n", size);
		ret = -EOPNOTSUPP;
	}

smbus_exit:
	hid_hw_power(hdev, PM_HINT_NORMAL);
	mutex_unlock(&dev->lock);
	return ret;
}