From: stigge@antcom.de (Roland Stigge)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH RESEND 0/6 v10] gpio: Add block GPIO
Date: Mon, 17 Dec 2012 19:02:45 +0100 [thread overview]
Message-ID: <50CF5E45.5030104@antcom.de> (raw)
In-Reply-To: <50CF584E.1040601@grandegger.com>
On 12/17/2012 06:37 PM, Wolfgang Grandegger wrote:
> /* Do synchronous data output with a single write access */
> __raw_writel(~mask, pio + PIO_OWDR);
> __raw_writel(mask, pio + PIO_OWER);
> __raw_writel(val, pio + PIO_ODSR);
>
> For caching we would need a storage. Not sure if it's worth compared to
> a context switch into the kernel.
Block GPIO is not only for you in userspace. ;-) You can also implement
efficient n-bit bus I/O in kernel drivers, n-bit-banging. :-) So not
always context switches involved.
Roland
WARNING: multiple messages have this Message-ID (diff)
From: Roland Stigge <stigge@antcom.de>
To: Wolfgang Grandegger <wg@grandegger.com>
Cc: rmallon@gmail.com, gregkh@linuxfoundation.org,
linus.walleij@linaro.org, broonie@opensource.wolfsonmicro.com,
w.sang@pengutronix.de, linux-kernel@vger.kernel.org,
grant.likely@secretlab.ca, daniel-gl@gmx.net, sr@denx.de,
plagnioj@jcrosoft.com, linux-arm-kernel@lists.infradead.org,
highguy@gmail.com
Subject: Re: [PATCH RESEND 0/6 v10] gpio: Add block GPIO
Date: Mon, 17 Dec 2012 19:02:45 +0100 [thread overview]
Message-ID: <50CF5E45.5030104@antcom.de> (raw)
In-Reply-To: <50CF584E.1040601@grandegger.com>
On 12/17/2012 06:37 PM, Wolfgang Grandegger wrote:
> /* Do synchronous data output with a single write access */
> __raw_writel(~mask, pio + PIO_OWDR);
> __raw_writel(mask, pio + PIO_OWER);
> __raw_writel(val, pio + PIO_ODSR);
>
> For caching we would need a storage. Not sure if it's worth compared to
> a context switch into the kernel.
Block GPIO is not only for you in userspace. ;-) You can also implement
efficient n-bit bus I/O in kernel drivers, n-bit-banging. :-) So not
always context switches involved.
Roland
next prev parent reply other threads:[~2012-12-17 18:02 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-14 14:26 [PATCH RESEND 0/6 v10] gpio: Add block GPIO Roland Stigge
2012-12-14 14:26 ` Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 1/6 v10] gpio: Add a block GPIO API to gpiolib Roland Stigge
2012-12-14 14:26 ` Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 2/6 v10] gpio: Add sysfs support to block GPIO API Roland Stigge
2012-12-14 14:26 ` Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 3/6 v10] gpio: Add userland device interface to block GPIO Roland Stigge
2012-12-14 14:26 ` Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 4/6 v10] gpiolib: Fix default attributes for class Roland Stigge
2012-12-14 14:26 ` Roland Stigge
2012-12-14 14:26 ` [PATCH RESEND 5/6 v10] gpio: Add device tree support to block GPIO API Roland Stigge
2012-12-14 14:26 ` Roland Stigge
2012-12-17 15:51 ` Mark Rutland
2012-12-17 15:51 ` Mark Rutland
2012-12-18 14:30 ` Roland Stigge
2012-12-18 14:30 ` Roland Stigge
2012-12-18 16:35 ` Mark Rutland
2012-12-18 16:35 ` Mark Rutland
2012-12-14 14:26 ` [PATCH RESEND 6/6 v10] gpio: Add block gpio to several gpio drivers Roland Stigge
2012-12-14 14:26 ` Roland Stigge
2012-12-14 17:58 ` [PATCH RESEND 0/6 v10] gpio: Add block GPIO Wolfgang Grandegger
2012-12-14 17:58 ` Wolfgang Grandegger
2012-12-14 23:49 ` Roland Stigge
2012-12-14 23:49 ` Roland Stigge
2012-12-15 10:51 ` Russell King - ARM Linux
2012-12-15 10:51 ` Russell King - ARM Linux
2012-12-17 11:37 ` Wolfgang Grandegger
2012-12-17 11:37 ` Wolfgang Grandegger
2012-12-17 11:51 ` Wolfgang Grandegger
2012-12-17 11:51 ` Wolfgang Grandegger
2012-12-17 12:10 ` Russell King - ARM Linux
2012-12-17 12:10 ` Russell King - ARM Linux
2012-12-17 14:57 ` Wolfgang Grandegger
2012-12-17 14:57 ` Wolfgang Grandegger
2012-12-17 13:32 ` Roland Stigge
2012-12-17 13:32 ` Roland Stigge
2012-12-17 13:51 ` Roland Stigge
2012-12-17 13:51 ` Roland Stigge
2012-12-17 16:28 ` Wolfgang Grandegger
2012-12-17 16:28 ` Wolfgang Grandegger
2012-12-17 17:15 ` Roland Stigge
2012-12-17 17:15 ` Roland Stigge
2012-12-17 17:37 ` Wolfgang Grandegger
2012-12-17 17:37 ` Wolfgang Grandegger
2012-12-17 18:02 ` Roland Stigge [this message]
2012-12-17 18:02 ` Roland Stigge
2012-12-17 19:47 ` Wolfgang Grandegger
2012-12-17 19:47 ` Wolfgang Grandegger
2012-12-17 21:33 ` Roland Stigge
2012-12-17 21:33 ` Roland Stigge
2012-12-18 6:51 ` Wolfgang Grandegger
2012-12-18 6:51 ` Wolfgang Grandegger
2012-12-18 5:55 ` Jean-Christophe PLAGNIOL-VILLARD
2012-12-18 5:55 ` Jean-Christophe PLAGNIOL-VILLARD
2012-12-18 6:58 ` Wolfgang Grandegger
2012-12-18 6:58 ` Wolfgang Grandegger
2012-12-18 7:54 ` Jean-Christophe PLAGNIOL-VILLARD
2012-12-18 7:54 ` Jean-Christophe PLAGNIOL-VILLARD
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