elan_i2c_read_block
retval = elan_i2c_read_block(client, reg, val, ETP_I2C_INF_LENGTH);
error = elan_i2c_read_block(client, ETP_I2C_DESC_CMD,
error = elan_i2c_read_block(client, ETP_I2C_REPORT_DESC_CMD,
return elan_i2c_read_block(client, ETP_I2C_CALIBRATE_CMD, val, 1);