From: u.kleine-koenig@pengutronix.de (Uwe Kleine-König)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/4] ARM: mx5/babbage: Use gpio_request_one in babbage_usbhub_reset
Date: Thu, 17 Mar 2011 08:55:46 +0100 [thread overview]
Message-ID: <20110317075545.GJ13316@pengutronix.de> (raw)
In-Reply-To: <1300326754-4629-2-git-send-email-festevam@gmail.com>
Hello Fabio,
On Wed, Mar 16, 2011 at 10:52:32PM -0300, Fabio Estevam wrote:
> Current code inside babbage_usbhub_reset uses gpio_direction_output with initial value of the GPIO and also sets
> the GPIO value via gpio_set_value to the same level right after. This is not needed.
>
> By using gpio_request_one it is possible to set the direction and initial value in one shot.
>
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
> arch/arm/mach-mx5/board-mx51_babbage.c | 9 +++------
> 1 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/mach-mx5/board-mx51_babbage.c b/arch/arm/mach-mx5/board-mx51_babbage.c
> index ff79395..cba8307 100644
> --- a/arch/arm/mach-mx5/board-mx51_babbage.c
> +++ b/arch/arm/mach-mx5/board-mx51_babbage.c
> @@ -209,17 +209,14 @@ static inline void babbage_usbhub_reset(void)
> int ret;
>
> /* Bring USB hub out of reset */
> - ret = gpio_request(BABBAGE_USB_HUB_RESET, "GPIO1_7");
> + ret = gpio_request_one(BABBAGE_USB_HUB_RESET,
> + GPIOF_OUT_INIT_LOW, "GPIO1_7");
> if (ret) {
> printk(KERN_ERR"failed to get GPIO_USB_HUB_RESET: %d\n", ret);
> return;
> }
> - gpio_direction_output(BABBAGE_USB_HUB_RESET, 0);
>
> - /* USB HUB RESET - De-assert USB HUB RESET_N */
> - msleep(1);
> - gpio_set_value(BABBAGE_USB_HUB_RESET, 0);
> - msleep(1);
> + msleep(2);
> gpio_set_value(BABBAGE_USB_HUB_RESET, 1);
> }
I think the first comment ("Bring USB hub out of reset") is wrong,
shouldn't it be:
/* reset USB hub */
ret = gpio_request_one(BABBAGE_USB_HUB_RESET, ...
if (ret)
...
msleep(2);
/* deassert reset */
gpio_set_value(BABBAGE_USB_HUB_RESET, 1);
because "bring out of reset" is only the set_value(.., 1);?
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-K?nig |
Industrial Linux Solutions | http://www.pengutronix.de/ |
next prev parent reply other threads:[~2011-03-17 7:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-17 1:52 [PATCH 1/4] ARM: mx5/babbage: Use gpio_request_one in babbage_fec_reset Fabio Estevam
2011-03-17 1:52 ` [PATCH 2/4] ARM: mx5/babbage: Use gpio_request_one in babbage_usbhub_reset Fabio Estevam
2011-03-17 1:52 ` [PATCH 3/4] ARM: mx5/mx53_evk: Use gpio_request_one in mx53_evk_fec_reset Fabio Estevam
2011-03-17 1:52 ` [PATCH 4/4] ARM: mx5/mx53_evk: Make the reset pin name more meaningful Fabio Estevam
2011-03-17 7:55 ` Uwe Kleine-König [this message]
2011-03-17 7:57 ` [PATCH 1/4] ARM: mx5/babbage: Use gpio_request_one in babbage_fec_reset Uwe Kleine-König
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=20110317075545.GJ13316@pengutronix.de \
--to=u.kleine-koenig@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).