Thread (20 messages) 20 messages, 5 authors, 2016-06-20

Re: [PATCH v3 1/2] usb: ohci-at91: Forcibly suspend ports while USB suspend

From: Alexandre Belloni <hidden>
Date: 2016-06-08 20:38:15
Also in: linux-arm-kernel, lkml

On 08/06/2016 at 15:26:51 -0500, Rob Herring wrote :
On Wed, Jun 08, 2016 at 12:15:10PM +0800, Wenyou Yang wrote:
quoted
In order to the save power consumption, as a workaround, suspend
forcibly the USB PORTA/B/C via set the SUSPEND_A/B/C bits of OHCI
Interrupt Configuration Register in the SFRs while OHCI USB suspend.

This suspend operation must be done before the USB clock is disabled,
resume after the USB clock is enabled.

Signed-off-by: Wenyou Yang <redacted>
---

Changes in v3:
 - Change the compatible description for more precise.

Changes in v2:
 - Add compatible to support forcibly suspend the ports.
 - Add soc/at91/at91_sfr.h to accommodate the defines.
 - Add error checking for .sfr_regmap.
 - Remove unnecessary regmap_read() statement.

 .../devicetree/bindings/usb/atmel-usb.txt          |  6 +-
 drivers/usb/host/ohci-at91.c                       | 80 +++++++++++++++++++++-
 include/soc/at91/at91_sfr.h                        | 29 ++++++++
 3 files changed, 112 insertions(+), 3 deletions(-)
 create mode 100644 include/soc/at91/at91_sfr.h
diff --git a/Documentation/devicetree/bindings/usb/atmel-usb.txt b/Documentation/devicetree/bindings/usb/atmel-usb.txt
index 5883b73..888deaa 100644
--- a/Documentation/devicetree/bindings/usb/atmel-usb.txt
+++ b/Documentation/devicetree/bindings/usb/atmel-usb.txt
@@ -3,8 +3,10 @@ Atmel SOC USB controllers
 OHCI
 
 Required properties:
- - compatible: Should be "atmel,at91rm9200-ohci" for USB controllers
-   used in host mode.
+ - compatible: Should be one of the following
+	       "atmel,at91rm9200-ohci" for USB controllers used in host mode.
+	       "atmel,sama5d2-ohci" for USB controllers used in host mode
+	       on SAMA5D2 which can force to suspend.
Guess I wasn't clear enough before. Drop "which can force to suspend".
Well, my point is that we don't need a new compatible anyway.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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