From 6d67bc40a1f5236fb00c503ab631819939efc01d Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Mon, 12 Oct 2015 08:52:00 +0100
Subject: [PATCH 201/222] BCM270X_DT: Reduce default at86rf233 SPI frequency
The AT86RF233 has been found to be unreliable on a 7.5MHz SPI bus,
so reduce the default frequency to 6MHz.
See: https://github.com/raspberrypi/linux/issues/1151
---
arch/arm/boot/dts/overlays/README | 2 +-
arch/arm/boot/dts/overlays/at86rf233-overlay.dts | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -178,7 +178,7 @@ Load: dtoverlay=at86rf233,<param>=<val
Params: interrupt GPIO used for INT (default 23)
reset GPIO used for Reset (default 24)
sleep GPIO used for Sleep (default 25)
- speed SPI bus speed in Hz (default 750000)
+ speed SPI bus speed in Hz (default 6000000)
trim Fine tuning of the internal capacitance
arrays (0=+0pF, 15=+4.5pF, default 15)
--- a/arch/arm/boot/dts/overlays/at86rf233-overlay.dts
+++ b/arch/arm/boot/dts/overlays/at86rf233-overlay.dts
@@ -25,7 +25,7 @@
interrupts = <23 4>; /* active high */
reset-gpio = <&gpio 24 1>;
sleep-gpio = <&gpio 25 1>;
- spi-max-frequency = <7500000>;
+ spi-max-frequency = <6000000>;
xtal-trim = /bits/ 8 <0xf>;
};
};