From 4c40db995eb54c3ee8cb5a8340640f49395d5f9e Mon Sep 17 00:00:00 2001 From: Xiaofei Tan Date: Wed, 7 Mar 2018 20:25:05 +0800 Subject: [PATCH] scsi: hisi_sas: dt-bindings: add an property of signal attenuation For some new boards with hip07 chipset we are required to set PHY config registers differently. The hw property which determines how to set these registers is in the PHY signal attenuation readings. This patch add an devicetree property, "hisilicon,signal-attenuation", which is used to describe the signal attenuation of an board. Cc: Rob Herring Cc: Mark Rutland Signed-off-by: Xiaofei Tan Signed-off-by: John Garry Reviewed-by: Rob Herring Signed-off-by: Martin K. Petersen --- Documentation/devicetree/bindings/scsi/hisilicon-sas.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/scsi/hisilicon-sas.txt b/Documentation/devicetree/bindings/scsi/hisilicon-sas.txt index df3bef7998fac..8c6659ed2cfc8 100644 --- a/Documentation/devicetree/bindings/scsi/hisilicon-sas.txt +++ b/Documentation/devicetree/bindings/scsi/hisilicon-sas.txt @@ -53,6 +53,13 @@ Main node required properties: Optional main node properties: - hip06-sas-v2-quirk-amt : when set, indicates that the v2 controller has the "am-max-transmissions" limitation. + - hisilicon,signal-attenuation : array of 3 32-bit values, containing de-emphasis, + preshoot, and boost attenuation readings for the board. They + are used to describe the signal attenuation of the board. These + values' range is 7600 to 12400, and used to represent -24dB to + 24dB. + The formula is "y = (x-10000)/10000". For example, 10478 + means 4.78dB. Example: sas0: sas@c1000000 { -- 2.30.2