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authorXiaofei Tan <tanxiaofei@huawei.com>2018-03-07 15:25:05 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2018-03-13 04:55:24 +0300
commit4c40db995eb54c3ee8cb5a8340640f49395d5f9e (patch)
treecafe0db0733cc198e09425db6845708228aa3766 /Documentation/devicetree/bindings/scsi
parent1875ede02ed5e176a18dccbca84abc28d5b3e141 (diff)
downloadlinux-4c40db995eb54c3ee8cb5a8340640f49395d5f9e.tar.xz
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 <robh+dt@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com> Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/devicetree/bindings/scsi')
-rw-r--r--Documentation/devicetree/bindings/scsi/hisilicon-sas.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/scsi/hisilicon-sas.txt b/Documentation/devicetree/bindings/scsi/hisilicon-sas.txt
index df3bef7998fa..8c6659ed2cfc 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 {