ch7006_read
det = ch7006_read(client, CH7006_DETECT);
priv->chip_version = ch7006_read(client, CH7006_VERSION_ID);
uint8_t ch7006_read(struct i2c_client *client, uint8_t addr);
#define ch7006_save_reg(client, state, reg) state->regs[reg] = ch7006_read(client, reg)