linux-kernel - Re: [PATCH 00/15 v4] Regulator ena

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Message-ID: <b2dd4b32-9929-19b1-c849-63d8c793c187@samsung.com>
Date:   Thu, 6 Dec 2018 14:27:03 +0100
From:   Marek Szyprowski <m.szyprowski@...sung.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>
Cc:     linux-kernel@...r.kernel.org,
        Charles Keepax <ckeepax@...nsource.cirrus.com>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: Re: [PATCH 00/15 v4] Regulator ena_gpiod fixups

Hi Linus,

On 2018-12-06 13:43, Linus Walleij wrote:
> Here is a fourth iteration of these fixups after fixing
> the (hopefullt last) bugs found in the v3 version.
>
> Also available in git branch
> gpio-descriptors-regulator-fixup in the GPIO git tree:
> https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git/log/?h=gpio-descriptors-regulator-fixup
>
> I added two fixup item to the list: making the gpiod
> from of node respect nonexlusive flags and fixing the
> shared regulators in devm_gpiod_get*.

Yeah! Finally it looks and works right. Feel free to add my:

Reviewed-by: Marek Szyprowski <m.szyprowski@...sung.com>

and

Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>

(to patches: 1-2, 5-10 and 13-15).


One more thing - if I got everything right, gpiod_put() in
*regulator_register() error path has to be removed also in
wm8994-regulator.c and arizona-ldo1.c.


> To make sure GPIO descriptors are never left dangling
> (as far as I can tell!) I use this stepwise approach:
>
> 1. Fix the regulator_register() in the core to guarantee
>    that after calling this with a valid GPIO descriptor
>    in ena_gpiod it will be gpiod_put() if there is any
>    problem.
>
> 2. Fix up simple descriptor consumers to just gpiod_get()
>    and let the core take over the descriptor. Only handle
>    the errorpath up to this point.
>
> 3. Export gpiod_get_from_of_node() and let max77686
>    obtain a GPIO descriptor from the device tree without
>    any devres make-up in the DT parsing callback.
>
> 4. Make gpiod_get_from_of_node() respect the
>    GPIOD_FLAGS_BIT_NONEXCLUSIVE flag.
>
> 5. Fix up devm_gpiod_get_* to respect the
>    GPIOD_FLAGS_BIT_NONEXCLUSIVE flag.
>
> 6. Invent devm_gpiod_unhinge() that will remove the devres
>    monitoring of a devm_* allocated GPIO descriptor
>    right before handling it over to the regulator core,
>    and use this in the otherwise hairy max8973, da9211,
>    s5m8767, tps65090 and s2mps11 drivers.
>
>
> Linus Walleij (15):
>   regulator: core: Track dangling GPIO descriptors
>   regulator: fixed: Let core handle GPIO descriptor
>   regulator: lm363x: Let core handle GPIO descriptor
>   regulator: lp8788-ldo: Let core handle GPIO descriptor
>   regulator: max8952: Let core handle GPIO descriptor
>   gpio: Export gpiod_get_from_of_node()
>   regulator: max77686: Let core handle GPIO descriptor
>   gpio: Enable nonexclusive gpiods from DT nodes
>   gpio: devres: Handle nonexclusive GPIOs
>   gpio: Add devm_gpiod_unhinge()
>   regulator: max8973: Let core handle GPIO descriptor
>   regulator: da9211: Hand over GPIO to regulator core
>   regulator: s5m8767: Hand over GPIO to regulator core
>   regulator: tps65090: Hand over GPIO to regulator core
>   regulator: s2mps11: Hand over GPIO to regulator core
>
>  Documentation/driver-model/devres.txt  |  1 +
>  drivers/gpio/gpiolib-devres.c          | 80 ++++++++++++++++++++++----
>  drivers/gpio/gpiolib.c                 |  2 +
>  drivers/gpio/gpiolib.h                 |  6 --
>  drivers/regulator/core.c               | 55 ++++++++++++++----
>  drivers/regulator/da9211-regulator.c   |  6 ++
>  drivers/regulator/fixed.c              |  6 +-
>  drivers/regulator/lm363x-regulator.c   |  8 ++-
>  drivers/regulator/lp8788-ldo.c         |  8 ++-
>  drivers/regulator/max77686-regulator.c | 14 +++--
>  drivers/regulator/max8952.c            | 10 +++-
>  drivers/regulator/max8973-regulator.c  |  8 ++-
>  drivers/regulator/s2mps11.c            |  7 ++-
>  drivers/regulator/s5m8767.c            |  9 ++-
>  drivers/regulator/tps65090-regulator.c |  6 ++
>  include/linux/gpio/consumer.h          | 23 ++++++++
>  16 files changed, 205 insertions(+), 44 deletions(-)
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland