LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Alexandre Courbot <gnurou@gmail.com>
To: Olliver Schinagl <oliver+list@schinagl.nl>
Cc: Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Kumar Gala <galak@codeaurora.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Bryan Wu <cooloney@gmail.com>, Richard Purdie <rpurdie@rpsys.net>,
	Olliver Schinagl <oliver@schinagl.nl>,
	Robin Gong <b38343@freescale.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Aaron Lu <aaron.lu@intel.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Grant Likely <grant.likely@linaro.org>,
	Wolfram Sang <wsa@the-dreams.de>,
	Alexander Shiyan <shc_work@mail.ru>,
	Jingoo Han <jg1.han@samsung.com>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	Linux Input <linux-input@vger.kernel.org>,
	"linux-leds@vger.kernel.org" <linux-leds@vger.kernel.org>
Subject: Re: [PATCH v1 2/4] gpio: add parameter to allow the use named gpios
Date: Mon, 19 Jan 2015 13:04:55 +0900	[thread overview]
Message-ID: <CAAVeFuLwTsX8HByCVyEucYJ_DhhCOP=tEDprmi9pBwx+a7zzJg@mail.gmail.com> (raw)
In-Reply-To: <1420621722-7428-3-git-send-email-oliver+list@schinagl.nl>

On Wed, Jan 7, 2015 at 6:08 PM, Olliver Schinagl
<oliver+list@schinagl.nl> wrote:
> From: Olliver Schinagl <oliver@schinagl.nl>
>
> The gpio binding document says that new code should always use named
> gpios. Patch 40b73183 added support to parse a list of gpios from child
> nodes, but does not make it possible to use named gpios. This patch adds
> the con_id property and implements it is done in gpiolib.c, where the
> old-style of using unnamed gpios still works.

This is absolutely correct - thanks for spotting this.

>
> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
> ---
>  drivers/gpio/devres.c                     | 16 +++++++++++++++-
>  drivers/input/keyboard/gpio_keys_polled.c |  2 +-
>  drivers/leds/leds-gpio.c                  |  2 +-
>  include/linux/gpio/consumer.h             |  1 +
>  4 files changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/devres.c b/drivers/gpio/devres.c
> index 13dbd3d..b7fbe1c 100644
> --- a/drivers/gpio/devres.c
> +++ b/drivers/gpio/devres.c
> @@ -111,23 +111,37 @@ EXPORT_SYMBOL(__devm_gpiod_get_index);
>  /**
>   * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node
>   * @dev:       GPIO consumer
> + * @con_id:    function within the GPIO consumer
>   * @child:     firmware node (child of @dev)
>   *
>   * GPIO descriptors returned from this function are automatically disposed on
>   * driver detach.
>   */
>  struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
> +                                           const char *con_id,
>                                             struct fwnode_handle *child)
>  {
> +       static const char const *suffixes[] = { "gpios", "gpio" };
> +       char prop_name[32]; /* 32 is max size of property name */
>         struct gpio_desc **dr;
>         struct gpio_desc *desc;
> +       unsigned int i;
>
>         dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
>                           GFP_KERNEL);
>         if (!dr)
>                 return ERR_PTR(-ENOMEM);
>
> -       desc = fwnode_get_named_gpiod(child, "gpios");
> +       for (i = 0; i < ARRAY_SIZE(suffixes); i++) {
> +               if (con_id)
> +                       snprintf(prop_name, 32, "%s-%s", con_id, suffixes[i]);
> +               else
> +                       snprintf(prop_name, 32, "%s", suffixes[i]);

Same remark as Dmitry about the hardcoded length of the string, but ...

> +
> +               desc = fwnode_get_named_gpiod(child, prop_name);
> +               if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
> +                       break;
> +       }

... since it looks like this part has been mostly copy/pasted from
of_find_gpio(), can you add another patch that fixes it there as well?

Also in the case of ACPI this will prove to be an incomplete lookup
since acpi_find_gpio() has an additional fallback if the named lookup
fails.

In that respect, I wonder if it would not be better for
devm_get_gpiod_from_child() to call of_find_gpio() and
acpi_find_gpio() (after making them non-static) followed by
gpiod_request() instead of calling fwnode_get_named_gpiod(). But in
that case it will have to do the OF/ACPI handling by itself.

I'm not really sure about which way is better. I'd appreciate if you
could give a thought to a possible refactoring that would improve the
situation ; otherwise feel free to ignore what I have written above
and to duplicate the property name building code.

  parent reply	other threads:[~2015-01-19  4:05 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-07  9:08 [PATCH v1 0/4] Let leds " Olliver Schinagl
2015-01-07  9:08 ` [PATCH v1 1/4] gpio:gpiolib: use static const char const * for a suffixes array Olliver Schinagl
2015-01-14 12:35   ` Linus Walleij
2015-01-07  9:08 ` [PATCH v1 2/4] gpio: add parameter to allow the use named gpios Olliver Schinagl
2015-01-08  0:15   ` Dmitry Torokhov
2015-01-14 12:36   ` Linus Walleij
2015-01-19  4:04   ` Alexandre Courbot [this message]
2015-01-21 21:44     ` Olliver Schinagl
2015-01-23  9:16       ` Alexandre Courbot
2015-01-07  9:08 ` [PATCH v1 3/4] leds: Let the binding document example for leds-gpio follow the gpio bindings Olliver Schinagl
2015-01-07 23:56   ` Dmitry Torokhov
2015-01-08  1:45   ` Rob Herring
2015-01-14 12:38   ` Linus Walleij
2015-01-07  9:08 ` [PATCH v1 4/4] leds: no longer use unnamed gpios Olliver Schinagl
2015-01-07 23:55   ` Dmitry Torokhov
2015-01-08  8:45     ` Olliver Schinagl
2015-01-08 14:40       ` Rob Herring
2015-01-08 22:12         ` Dmitry Torokhov
2015-01-14 12:45           ` Linus Walleij
2015-01-14 13:20             ` Olliver Schinagl
2015-01-19  3:43               ` Alexandre Courbot
2015-01-19  4:09                 ` Alexandre Courbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAAVeFuLwTsX8HByCVyEucYJ_DhhCOP=tEDprmi9pBwx+a7zzJg@mail.gmail.com' \
    --to=gnurou@gmail.com \
    --cc=aaron.lu@intel.com \
    --cc=b38343@freescale.com \
    --cc=cooloney@gmail.com \
    --cc=devicetree@vger.kernel.org \
    --cc=dmitry.torokhov@gmail.com \
    --cc=galak@codeaurora.org \
    --cc=grant.likely@linaro.org \
    --cc=ijc+devicetree@hellion.org.uk \
    --cc=jg1.han@samsung.com \
    --cc=linus.walleij@linaro.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-input@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-leds@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mika.westerberg@linux.intel.com \
    --cc=oliver+list@schinagl.nl \
    --cc=oliver@schinagl.nl \
    --cc=pawel.moll@arm.com \
    --cc=rafael.j.wysocki@intel.com \
    --cc=robh+dt@kernel.org \
    --cc=rpurdie@rpsys.net \
    --cc=shc_work@mail.ru \
    --cc=wsa@the-dreams.de \
    --subject='Re: [PATCH v1 2/4] gpio: add parameter to allow the use named gpios' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).