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* [PATCH] AT91, DT, usb gadget: disable pull-up on vbus-gpio (PB16) to reduce power consumption
@ 2015-01-15 16:00 Sylvain Rochet
  2015-01-16  6:22 ` Bo Shen
  0 siblings, 1 reply; 5+ messages in thread
From: Sylvain Rochet @ 2015-01-15 16:00 UTC (permalink / raw)
  To: linux-arm-kernel

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 no even work
if the pull-up is stronger than usual.

Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
---
 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..f622f96 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, no pull up and deglitch */
+					};
+				};
 			};
 
 			spi0: spi at f0000000 {
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2015-01-16 15:08 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
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
2015-01-16 15:08       ` Nicolas Ferre

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