linux-kernel - Re: [PATCH v5 0/8] Migrate i8255 GPIO drivers to regmap API

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Message-ID: <CAMRc=MdgQUvjKxr7GTpbq0AzSmhiOHvRmCx7UbiqF__w8Y+P7Q@mail.gmail.com>
Date:   Fri, 30 Dec 2022 14:07:31 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     William Breathitt Gray <william.gray@...aro.org>
Cc:     linus.walleij@...aro.org, andriy.shevchenko@...ux.intel.com,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        michael@...le.cc
Subject: Re: [PATCH v5 0/8] Migrate i8255 GPIO drivers to regmap API

On Tue, Dec 27, 2022 at 3:32 PM William Breathitt Gray
<william.gray@...aro.org> wrote:
>
> Changes in v5:
>  - Add REGMAP_MMIO Kconfig selection for GPIO_104_DIO_48E,
>    GPIO_104_IDI_48, and GPIO_GPIO_MM
>  - Replace magic number 0x3 with GENMASK(1, 0) to make intent clear in
>    the dio48e_handle_mask_sync() function
>  - Write (instead of read) to clear interrupts on unmask; although the
>    datasheet lists the respective register as read/write, all other
>    references state that this should be a write operation to clear
>
> The regmap API supports IO port accessors so we can take advantage of
> regmap abstractions rather than handling access to the device registers
> directly in the driver. The 104-dio-48e and gpio-mm modules depend on
> the i8255 library and are thus updated accordingly.
>
> The 104-IDI-48 is hardwired as an input-only device. Because the i8255
> control registers are not exposed on the 104-IDI-48, the i8255 library
> doesn't provide much benefit here. In this case it's simpler to utilize
> the gpio_regmap API directly, so this patch series does such and removes
> the i8255 library dependency from the 104-idi-48 module.
>
> The first patch in this series adjusts gpio_regmap to always set
> gpio_chip get_direction. This patch is mostly independent of the rest of
> the patches in the series and can be picked up separately if desired.
> I'm including it here because it allows the input-only 104-idi-48 driver
> to continue reporting offset directions after migrating to gpio_regmap.
>
> By leveraging the gpio_regmap API, the i8255 library is reduced to
> simply a devm_i8255_regmap_register() function, a configuration
> structure struct i8255_regmap_config, and a helper macro
> i8255_volatile_regmap_range() provided to simplify volatile PPI register
> hinting for the regmap.
>
> The regmap_irq API is leveraged by the 104-idi-48 and 104-dio-48e
> modules to support their IRQ functionality. Do their respective regmap
> configurations need use_hwlock set to true in this case, or is adequate
> locking already handled by the regmap_irq API?
>
> William Breathitt Gray (8):
>   gpio: regmap: Always set gpio_chip get_direction
>   gpio: 104-dio-48e: Migrate to the regmap-irq API
>   gpio: 104-idi-48: Migrate to the regmap-irq API
>   gpio: 104-idi-48: Migrate to gpio-regmap API
>   gpio: i8255: Migrate to gpio-regmap API
>   gpio: 104-dio-48e: Migrate to regmap API
>   gpio: gpio-mm: Migrate to regmap API
>   gpio: i8255: Remove unused legacy interface
>
>  drivers/gpio/Kconfig            |   8 +-
>  drivers/gpio/gpio-104-dio-48e.c | 398 +++++++++++---------------------
>  drivers/gpio/gpio-104-idi-48.c  | 336 +++++++++------------------
>  drivers/gpio/gpio-gpio-mm.c     | 154 +++---------
>  drivers/gpio/gpio-i8255.c       | 320 +++++++------------------
>  drivers/gpio/gpio-i8255.h       |  54 ++---
>  drivers/gpio/gpio-regmap.c      |   7 +-
>  7 files changed, 390 insertions(+), 887 deletions(-)
>
>
> base-commit: 1b929c02afd37871d5afb9d498426f83432e71c2
> --
> 2.38.1
>

Series applied, thanks!

Bart