From: alexandre.belloni@free-electrons.com (Alexandre Belloni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] AT91, DT, usb gadget: disable pull-up on vbus-gpio (PB16) to reduce power consumption
Date: Fri, 16 Jan 2015 11:43:04 +0100 [thread overview]
Message-ID: <20150116104304.GC3843@piout.net> (raw)
In-Reply-To: <1421401839-29370-1-git-send-email-sylvain.rochet@finsecur.com>
On 16/01/2015 at 10:50:39 +0100, Sylvain Rochet wrote :
> There is an external resistor divider on PB16, acting like a pull-down,
> the pull-up increase power consumption and prevent the vbus detect pin
> to reach Vss voltage, ~1.5V mesured on my board, it might not even work
> if the pull-up is stronger than usual.
>
> Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
You should have added the ack from Bo here too.
> ---
> Improved GPIO comment, fixed typo in commit summary.
>
> arch/arm/boot/dts/at91sam9x5ek.dtsi | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm/boot/dts/at91sam9x5ek.dtsi b/arch/arm/boot/dts/at91sam9x5ek.dtsi
> index 3a9f6fa..bd16bd3 100644
> --- a/arch/arm/boot/dts/at91sam9x5ek.dtsi
> +++ b/arch/arm/boot/dts/at91sam9x5ek.dtsi
> @@ -53,6 +53,8 @@
> };
>
> usb2: gadget at f803c000 {
> + pinctrl-names = "default";
> + pinctrl-0 = <&pinctrl_board_usb2>;
> atmel,vbus-gpio = <&pioB 16 GPIO_ACTIVE_HIGH>;
> status = "okay";
> };
> @@ -80,6 +82,13 @@
> <AT91_PIOD 14 AT91_PERIPH_GPIO AT91_PINCTRL_PULL_UP_DEGLITCH>; /* PD14 gpio CD pin pull up and deglitch */
> };
> };
> +
> + usb2 {
> + pinctrl_board_usb2: usb2-board {
> + atmel,pins =
> + <AT91_PIOB 16 AT91_PERIPH_GPIO AT91_PINCTRL_DEGLITCH>; /* PB16 gpio vbus sense, deglitch */
> + };
> + };
> };
>
> spi0: spi at f0000000 {
> --
> 2.1.4
>
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
next prev parent reply other threads:[~2015-01-16 10:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-15 16:00 [PATCH] AT91, DT, usb gadget: disable pull-up on vbus-gpio (PB16) to reduce power consumption Sylvain Rochet
2015-01-16 6:22 ` Bo Shen
2015-01-16 9:50 ` [PATCH v2] " Sylvain Rochet
2015-01-16 10:43 ` Alexandre Belloni [this message]
2015-01-16 15:08 ` Nicolas Ferre
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