Re: [PATCH v2 4/6] media: uapi: Add mlx7502x header file

[Volodymyr Kharuk <vkh@melexis.com>]

Hi Laurent,

Thank you for your review.

On Thu, Jul 14, 2022 at 01:31:35PM +0300, Laurent Pinchart wrote:
> Hi Volodymyr,
> 
> Thank you for the patch.
> 
> On Thu, Jul 14, 2022 at 11:34:46AM +0300, Volodymyr Kharuk wrote:
> > Define user controls for mlx7502x driver and update MAINTAINERS
> > 
> > Signed-off-by: Volodymyr Kharuk <vkh@melexis.com>
> > ---
> >  MAINTAINERS                   |  7 +++++++
> >  include/uapi/linux/mlx7502x.h | 31 +++++++++++++++++++++++++++++++
> >  2 files changed, 38 insertions(+)
> >  create mode 100644 include/uapi/linux/mlx7502x.h
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index ef3ec334fae9..1a68d888ee14 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -12673,6 +12673,13 @@ S:	Supported
> >  W:	http://www.melexis.com
> >  F:	drivers/iio/temperature/mlx90632.c
> >  
> > +MELEXIS MLX7502X DRIVER
> > +M:	Volodymyr Kharuk <vkh@melexis.com>
> > +L:	linux-media@vger.kernel.org
> > +S:	Supported
> > +W:	http://www.melexis.com
> > +F:	include/uapi/linux/mlx7502x.h
> > +
> >  MELFAS MIP4 TOUCHSCREEN DRIVER
> >  M:	Sangwon Jee <jeesw@melfas.com>
> >  S:	Supported
> > diff --git a/include/uapi/linux/mlx7502x.h b/include/uapi/linux/mlx7502x.h
> > new file mode 100644
> > index 000000000000..44386f3d6f5a
> > --- /dev/null
> > +++ b/include/uapi/linux/mlx7502x.h
> > @@ -0,0 +1,31 @@
> > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> > +/*
> > + * Melexis 7502x ToF cameras driver.
> > + *
> > + * Copyright (C) 2021 Melexis N.V.
> > + *
> > + */
> > +
> > +#ifndef __UAPI_MLX7502X_H_
> > +#define __UAPI_MLX7502X_H_
> > +
> > +#include <linux/v4l2-controls.h>
> > +
> 
> These controls should be documented, in
> Documentation/userspace-api/media/drivers/.
Ok, will do in v3
> 
> > +/* number of phases per frame: 1..8 */
> > +#define V4L2_CID_MLX7502X_PHASE_NUMBER  (V4L2_CID_USER_MLX7502X_BASE + 0)
> > +/* shift of each phase in frame, this is an array of 8 elements, each 16bits */
> > +#define V4L2_CID_MLX7502X_PHASE_SEQ	(V4L2_CID_USER_MLX7502X_BASE + 1)
> > +/* frequency modulation in MHz */
> > +#define V4L2_CID_MLX7502X_FMOD		(V4L2_CID_USER_MLX7502X_BASE + 2)
> > +/* time integration of each phase in us */
> > +#define V4L2_CID_MLX7502X_TINT		(V4L2_CID_USER_MLX7502X_BASE + 3)
> 
> Are these control very device-specific, or are they concept that apply
> in general to ToF sensors ? Same for V4L2_CID_MLX7502X_OUTPUT_MODE.
These controls(except V4L2_CID_MLX7502X_OUTPUT_MODE) are general for ToF
sensors. Do you think we should standardize them?

Note that the control V4L2_CID_MLX7502X_TINT is similar to
V4L2_CID_EXPOSURE, but the way it is done in ToF is different. They don't
have a shutter. So I gave a separate control name. Is it ok?
> 
> > +/* mode could sw(sending i2c packet), hw(pin triggering), and continuous(self triggering) */
> > +#define V4L2_CID_MLX7502X_TRIGGER_MODE	(V4L2_CID_USER_MLX7502X_BASE + 4)
> > +/* in case sw or hw trigger mode is used */
> > +#define V4L2_CID_MLX7502X_TRIGGER	(V4L2_CID_USER_MLX7502X_BASE + 5)
> 
> Trigger control is likely something we need to standardize at the V4L2
> level.
Ok, then I'll remove these controls for now and I will back with this as
a separate patch.
> 
> > +/* this is related to the taps in ToF cameras, usually A minus B is the best option */
> > +#define V4L2_CID_MLX7502X_OUTPUT_MODE	(V4L2_CID_USER_MLX7502X_BASE + 6)
> > +/* ToF camers has its own temperature sensor, which can be read out only during streaming */
> > +#define V4L2_CID_MLX7502X_TEMPERATURE	(V4L2_CID_USER_MLX7502X_BASE + 7)
> 
> This should probably use the proposed temperature control from
> https://lore.kernel.org/linux-media/20220415111845.27130-3-benjamin.mugnier@foss.st.com/
Ok, then I'll remove these controls for now.
> 
> > +
> > +#endif /* __UAPI_MLX7502X_H_ */
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
--
Volodymyr Kharuk