From a78ad9a34f11fecfdcd08675396bf2bf163a3f4d Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Mon, 12 Oct 2015 08:52:00 +0100
Subject: [PATCH 201/203] 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>;
 			};
 		};