linux-kernel - Re: [PATCH v6 00/20] leds: leds-lp55xx: overhaul driver

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Message-ID: <20240620160907.GP3029315@google.com>
Date: Thu, 20 Jun 2024 17:09:07 +0100
From: Lee Jones <lee@...nel.org>
To: Christian Marangi <ansuelsmth@...il.com>
Cc: Pavel Machek <pavel@....cz>, Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Jacek Anaszewski <jacek.anaszewski@...il.com>,
	linux-leds@...r.kernel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v6 00/20] leds: leds-lp55xx: overhaul driver

On Sun, 16 Jun 2024, Christian Marangi wrote:

> This long series is (as requested) a big overhaul of the lp55xx based
> LED driver.
> 
> As notice for these kind of LED chip there was the bad habit of copy
> the old driver and just modify it enough to make it work with the new
> model. Till v4 I was also doing the same by following the pattern and
> the code format of previous driver.
> 
> Since Lee didn't like this, here is the BIG series that generalize
> pretty much anything in the 4 model currently supported.
> 
> Indeed, although the LED chip have fundamental difference (page
> support), things can be generalized and produce slimmer drivers by
> putting everything in the lp55xx-common shared module.
> 
> This result in the new model lp5569 being very small with only the
> selftest portion to be custom.
> 
> Lee also wasn't clear by the meaning of ENGINE in these LED driver,
> so here some simple explaination. This is very common on these TI LED
> chip. The ENGINE (there are always 3) is just some kind of processor
> that execute a program (precompiled code ASM like) loaded in the SRAM.
> Sysfs is used to load the pattern, and to start and stop the engine.
> 
> These pattern can do all kind of complex thing with LEDs. Old LED chip
> had 32bytes of space for the pattern but newer one (like lp5569) have
> pages and if correctly configured can have massive pattern.
> These pattern can do all kind of magic like loops that make the LED
> pulse, change color and all kind of stuff.
> 
> (For Lee, sorry if you will have to repeat some review that I might
>  have missed in the lp5569 driver)
> 
> Changes v6:
> - Fix compilation warning for ret unused in read_poll_timeout
>   (no idea why this is flagged only on some particular arch...)
> - Fix missing bitfield.h in lp55x-common.c (again it seems this
>   header gets included in the flow if the arch use them or not...)
> Changes v5:
> - Big generalization patch
> - Rework lp5569 driver with new generalized functions
> - Drop all copyright header in lp5569 as the driver got reworked
>   entirely and it's not based on previous one anymore.
> Changes v4:
> - Fix reported buffer overflow due to a copypaste error
> - Add comments to describe fw size logic
> Changes v3:
> - Add ACK tag to DT patch
> - Enlarge and support program size up to 128bytes
> Changes v2:
> - Add ACK tag to DT patch
> - Fix compilation error with target that doesn't
>   include bitfield.h
> 
> Christian Marangi (20):
>   dt-bindings: leds-lp55xx: limit pwr-sel property to ti,lp8501
>   dt-bindings: leds-lp55xx: Add new ti,lp5569 compatible
>   leds: leds-lp55xx: generalize stop_all_engine OP
>   leds: leds-lp55xx: generalize probe/remove functions
>   leds: leds-lp55xx: generalize load_engine function
>   leds: leds-lp55xx: generalize load_engine_and_select_page function
>   leds: leds-lp55xx: generalize run_engine function
>   leds: leds-lp55xx: generalize update_program_memory function
>   leds: leds-lp55xx: generalize firmware_loaded function
>   leds: leds-lp55xx: generalize led_brightness function
>   leds: leds-lp55xx: generalize multicolor_brightness function
>   leds: leds-lp55xx: generalize set_led_current function
>   leds: leds-lp55xx: generalize turn_off_channels function
>   leds: leds-lp55xx: generalize stop_engine function
>   leds: leds-lp55xx: generalize sysfs engine_load and engine_mode
>   leds: leds-lp55xx: generalize sysfs engine_leds
>   leds: leds-lp55xx: generalize sysfs master_fader
>   leds: leds-lp55xx: support ENGINE program up to 128 bytes
>   leds: leds-lp55xx: drop deprecated defines
>   leds: leds-lp5569: Add support for Texas Instruments LP5569
> 
>  .../devicetree/bindings/leds/leds-lp55xx.yaml |  11 +
>  drivers/leds/Kconfig                          |  16 +-
>  drivers/leds/Makefile                         |   1 +
>  drivers/leds/leds-lp5521.c                    | 405 +---------
>  drivers/leds/leds-lp5523.c                    | 728 ++---------------
>  drivers/leds/leds-lp5562.c                    | 261 +------
>  drivers/leds/leds-lp5569.c                    | 542 +++++++++++++
>  drivers/leds/leds-lp55xx-common.c             | 730 +++++++++++++++++-
>  drivers/leds/leds-lp55xx-common.h             | 133 +++-
>  drivers/leds/leds-lp8501.c                    | 313 +-------
>  10 files changed, 1523 insertions(+), 1617 deletions(-)
>  create mode 100644 drivers/leds/leds-lp5569.c

Generally, I love it - what a difference!

Couple of small things within the patches and few general points.

* Ensure scripts/checkpatch.pl is happy before resubmitting.
* Please place my Suggested-by in all of the consolidation patches.
* Subject titles should always match that of the subsystem
  - In our case the first letter of the description should be uppercase

Thanks for doing this, it's great work.

-- 
Lee Jones [李琼斯]