From: Linus Walleij <linus.walleij@linaro.org>
To: Lars Poeschel <larsi@wh2.tu-dresden.de>
Cc: poeschel@lemonage.de, grant.likely@secretlab.ca,
rob.herring@calxeda.com, rob@landley.net,
devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org,
spi-devel-general@lists.sourceforge.net, w.sang@pengutronix.de,
ben-linux@fluff.org, linux-i2c@vger.kernel.org
Subject: Re: [PATCH RFC 1/1] gpio: mcp23s08: convert driver to DT
Date: Thu, 31 Jan 2013 21:51:36 +0100 [thread overview]
Message-ID: <CACRpkda_HjzWNMD1H_a_fsWtbRWuTDsutS8kndb9jY31qf7Yyg@mail.gmail.com> (raw)
In-Reply-To: <1359647903-15801-2-git-send-email-larsi@wh2.tu-dresden.de>
On Thu, Jan 31, 2013 at 4:58 PM, Lars Poeschel <larsi@wh2.tu-dresden.de> wrote:
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
> @@ -0,0 +1,27 @@
> +Microchip MCP2308/MCP23S08/MCP23017/MCP23S17 driver for
> +8-/16-bit I/O expander with serial interface (I2C/SPI)
> +
> +Required properties:
> +- compatible : Should be "mcp,mcp23s08-gpio", "mcp,mcp23s17-gpio",
> + "mcp,mcp23008-gpio" or "mcp,mcp23017-gpio"
> +- base : The first gpio number that should be assigned by this chip.
No. We do not tie the global GPIO numbers into the device tree.
In the DT GPIOs are referenced by ampersand <&gpio0 1 2>
notation referring to the instance, so as you realize DT itself
has no need for that number.
Further it is not OS-neutral.
You have to find another way to handle this in the driver code.
In worst case: use AUXDATA.
Yours,
Linus Walleij
WARNING: multiple messages have this Message-ID (diff)
From: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
To: Lars Poeschel <larsi-myOXECIRRCL4ajHJ1XSv27NAH6kLmebB@public.gmane.org>
Cc: ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org,
linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
poeschel-Xtl8qvBWbHwb1SvskN2V4Q@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org,
w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
rob-VoJi6FS/r0vR7s880joybQ@public.gmane.org,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: [PATCH RFC 1/1] gpio: mcp23s08: convert driver to DT
Date: Thu, 31 Jan 2013 21:51:36 +0100 [thread overview]
Message-ID: <CACRpkda_HjzWNMD1H_a_fsWtbRWuTDsutS8kndb9jY31qf7Yyg@mail.gmail.com> (raw)
In-Reply-To: <1359647903-15801-2-git-send-email-larsi-myOXECIRRCL4ajHJ1XSv27NAH6kLmebB@public.gmane.org>
On Thu, Jan 31, 2013 at 4:58 PM, Lars Poeschel <larsi-myOXECIRRCL4ajHJ1XSv27NAH6kLmebB@public.gmane.org> wrote:
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
> @@ -0,0 +1,27 @@
> +Microchip MCP2308/MCP23S08/MCP23017/MCP23S17 driver for
> +8-/16-bit I/O expander with serial interface (I2C/SPI)
> +
> +Required properties:
> +- compatible : Should be "mcp,mcp23s08-gpio", "mcp,mcp23s17-gpio",
> + "mcp,mcp23008-gpio" or "mcp,mcp23017-gpio"
> +- base : The first gpio number that should be assigned by this chip.
No. We do not tie the global GPIO numbers into the device tree.
In the DT GPIOs are referenced by ampersand <&gpio0 1 2>
notation referring to the instance, so as you realize DT itself
has no need for that number.
Further it is not OS-neutral.
You have to find another way to handle this in the driver code.
In worst case: use AUXDATA.
Yours,
Linus Walleij
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next prev parent reply other threads:[~2013-01-31 20:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-31 15:58 [PATCH RFC 0/1] Convert mcp23s08 to DT usage Lars Poeschel
2013-01-31 15:58 ` Lars Poeschel
2013-01-31 15:58 ` [PATCH RFC 1/1] gpio: mcp23s08: convert driver to DT Lars Poeschel
2013-01-31 15:58 ` Lars Poeschel
2013-01-31 20:51 ` Linus Walleij [this message]
2013-01-31 20:51 ` Linus Walleij
2013-02-05 14:29 ` Grant Likely
2013-02-05 14:29 ` Grant Likely
2013-02-06 9:31 ` Lars Poeschel
2013-02-06 9:31 ` Lars Poeschel
2013-02-06 9:37 ` Linus Walleij
2013-02-06 9:37 ` Linus Walleij
2013-02-09 14:24 ` Grant Likely
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