From: Michael Walle <michael@walle.cc>
To: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: linux-gpio <linux-gpio@vger.kernel.org>,
linux-devicetree <devicetree@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-hwmon@vger.kernel.org, linux-pwm@vger.kernel.org,
LINUXWATCHDOG <linux-watchdog@vger.kernel.org>,
arm-soc <linux-arm-kernel@lists.infradead.org>,
"Linus Walleij" <linus.walleij@linaro.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Jean Delvare" <jdelvare@suse.com>,
"Guenter Roeck" <linux@roeck-us.net>,
"Lee Jones" <lee.jones@linaro.org>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Wim Van Sebroeck" <wim@linux-watchdog.org>,
"Shawn Guo" <shawnguo@kernel.org>, "Li Yang" <leoyang.li@nxp.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Jason Cooper" <jason@lakedaemon.net>,
"Marc Zyngier" <maz@kernel.org>,
"Mark Brown" <broonie@kernel.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v2 10/16] gpio: add a reusable generic gpio_chip using regmap
Date: Tue, 14 Apr 2020 21:57:15 +0200 [thread overview]
Message-ID: <eab972adf53bbac20b5a9e613fcfb5b0@walle.cc> (raw)
In-Reply-To: <62d157198a75a59ada15c496deeab49b@walle.cc>
Hi Mark, Hi Bartosz, Hi Linus,
Am 2020-04-14 20:41, schrieb Michael Walle:
> Am 2020-04-14 19:00, schrieb Bartosz Golaszewski:
>> wt., 14 kwi 2020 o 12:07 Michael Walle <michael@walle.cc> napisał(a):
>>> >>
>>> >> So the best from a user perspective I've could come up with was:
>>> >>
>>> >> ->base_reg = GPIO_REGMAP_ADDR(addr);
>>> >>
>>> >> I'm open for suggestions.
>>> >>
>>> >
>>> > Maybe setting the pointer to ERR_PTR(-ENOENT) which will result in
>>> > IS_ERR() returning true?
>>>
>>> Unfortunatly, its not a pointer, but only a regular unsigned int (ie
>>> the type the regmap API has for its "reg" property). It could be a
>>> pointer of course but then the user would have to allocate additional
>>> memory.
>>>
>>> -michael
>>>
>>
>> Eek, of course it's not a pointer. If possible I'd like to avoid this
>> GPIO_REGMAP_ADDR() macro, so how about having some separate field for
>> invalid offsets making every offset 'valid' by default?
>
> IMHO this has the same problems as mentioned in the response to Mark's
> idea. Normally, the user sets only some addresses, thus he has to mark
> all other as invalid. And if you add another address, you have to touch
> all the drivers to mark it as invalid.
>
> We could add some force bits like the "use_ack" flag in the bgpio
> driver,
> where you can force the use of the value 0. But I'd really like to find
> a better way..
So what about the following:
#define GPIO_REGMAP_ADDR_ZERO (unsigned int)(-1)
So this way the user might assign the base addresses the normal way
except when he wants to use zero, in that case he has to use
->base_adr = GPIO_REGMAP_ADDR_ZERO;
gpio-regmap.c could use then:
if (base_addr)
something_useful(gpio_regmap_addr(base_addr));
unsigned int gpio_regmap_addr(unsigned int addr)
{
return (addr == GPIO_REGMAP_ADDR_ZERO) ? 0 : addr;
}
-michael
next prev parent reply other threads:[~2020-04-14 19:57 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-02 20:36 [PATCH v2 00/16] Add support for Kontron sl28cpld Michael Walle
2020-04-02 20:36 ` [PATCH v2 01/16] include/linux/ioport.h: add helper to define REG resource constructs Michael Walle
2020-04-02 20:36 ` [PATCH v2 02/16] mfd: mfd-core: Don't overwrite the dma_mask of the child device Michael Walle
2020-04-02 20:36 ` [PATCH v2 03/16] mfd: mfd-core: match device tree node against reg property Michael Walle
2020-04-02 20:36 ` [PATCH v2 04/16] regmap-irq: make it possible to add irq_chip do a specific device node Michael Walle
2020-04-14 15:37 ` Applied "regmap-irq: make it possible to add irq_chip do a specific device node" to the regmap tree Mark Brown
2020-04-14 17:12 ` [PATCH v2 04/16] regmap-irq: make it possible to add irq_chip do a specific device node Mark Brown
2020-04-02 20:36 ` [PATCH v2 05/16] dt-bindings: mfd: Add bindings for sl28cpld Michael Walle
2020-04-02 20:36 ` [PATCH v2 06/16] mfd: Add support for Kontron sl28cpld management controller Michael Walle
2020-04-02 20:36 ` [PATCH v2 07/16] irqchip: add sl28cpld interrupt controller support Michael Walle
2020-04-02 20:36 ` [PATCH v2 08/16] watchdog: add support for sl28cpld watchdog Michael Walle
2020-04-03 6:25 ` Guenter Roeck
2020-04-02 20:36 ` [PATCH v2 09/16] pwm: add support for sl28cpld PWM controller Michael Walle
2020-04-02 20:36 ` [PATCH v2 10/16] gpio: add a reusable generic gpio_chip using regmap Michael Walle
2020-04-06 7:47 ` Bartosz Golaszewski
2020-04-06 10:10 ` Michael Walle
2020-04-14 9:50 ` Bartosz Golaszewski
2020-04-14 10:07 ` Michael Walle
2020-04-14 17:00 ` Bartosz Golaszewski
2020-04-14 18:41 ` Michael Walle
2020-04-14 19:57 ` Michael Walle [this message]
2020-04-16 9:20 ` Linus Walleij
2020-04-16 9:34 ` Michael Walle
2020-04-14 17:21 ` Mark Brown
2020-04-14 18:36 ` Michael Walle
2020-04-14 18:39 ` Mark Brown
2020-04-16 9:27 ` Linus Walleij
2020-04-17 6:34 ` Michael Walle
2020-04-21 10:50 ` Michael Walle
2020-04-02 20:36 ` [PATCH v2 11/16] gpio: add support for the sl28cpld GPIO controller Michael Walle
2020-04-16 8:34 ` Linus Walleij
2020-04-16 8:55 ` Michael Walle
2020-04-02 20:36 ` [PATCH v2 12/16] hwmon: add support for the sl28cpld hardware monitoring controller Michael Walle
2020-04-02 21:30 ` Guenter Roeck
2020-04-02 20:36 ` [PATCH v2 13/16] arm64: dts: freescale: sl28: enable sl28cpld Michael Walle
2020-04-02 20:36 ` [PATCH v2 14/16] arm64: dts: freescale: sl28: map GPIOs to input events Michael Walle
2020-04-02 20:36 ` [PATCH v2 15/16] arm64: dts: freescale: sl28: enable LED support Michael Walle
2020-04-02 20:36 ` [PATCH v2 16/16] arm64: dts: freescale: sl28: enable fan support Michael Walle
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