Re: [PATCH v4 0/2] iio: proximity: add driver for ST VL53L1X ToF sensor

[Andy Shevchenko]

On Fri, Mar 13, 2026 at 12:37:16AM +0600, Siratul Islam wrote:
> This series adds support for the STMicroelectronics VL53L1X
> Time-of-Flight ranging sensor.
> 
> The VL53L1X is a ToF laser-ranging sensor with I2C interface,
> capable of measuring distances up to 4 meters. The driver
> supports both interrupt-driven and polled operation.
> 
> Why a separate driver is needed (instead of extending vl53l0x-i2c.c):
> The VL53L1X is fundamentally different from the VL53L0X despite the
> similar naming. Extending the existing driver would require rewriting
> the majority of it.
> 
> Key differences include:
> - A different register map (16-bit addresses vs. 8-bit addresses).
> - Requires a 91-byte firmware configuration blob to be loaded at boot.
> - Requires a VHV calibration cycle.
> - Has distance mode and timing budget configurations.
> - Uses the regmap API rather than raw i2c_smbus calls.
> 
> I also reviewed other drivers in drivers/iio/proximity/ and can
> confirm this IP block does not appear to be shared by any other
> existing driver.
> 
> Tested on Raspberry Pi 5 with a VL53L1X breakout board.
> 
> Note on vdd-supply:
> In v2, I added vdd-supply as required. Since I'm using the
> shared st,vl53l0x.yaml binding now, I had to drop that requirement
> to avoid breaking backward compatibility for existing st,vl53l0x
> devicetrees. The driver itself still uses non-optional
> devm_regulator_get() so no change there.

> ---
> Changes in v4:
> - Move i2c_check_functionality() to the top of probe before allocations.
> - Use struct u32_fract for oscillator correction math.
> - Explicitly set .cache_type = REGCACHE_NONE.
> - Document intentional predisable drain
> - Use dev_err_probe() for firmware boot timeout and remove duplicate IRQ request error message.
> - Use sizeof() in regmap bulk read/writes instead of hardcoded lengths.
> - Add missing headers (<linux/math.h>, <linux/time.h>, <asm/byteorder.h>).
> - Various formatting cleanups per Andy's review.

NAK. we haven't settled down on the v3 comments.

-- 
With Best Regards,
Andy Shevchenko