1 From a78ad9a34f11fecfdcd08675396bf2bf163a3f4d Mon Sep 17 00:00:00 2001
2 From: Phil Elwell <phil@raspberrypi.org>
3 Date: Mon, 12 Oct 2015 08:52:00 +0100
4 Subject: [PATCH 201/203] BCM270X_DT: Reduce default at86rf233 SPI frequency
6 The AT86RF233 has been found to be unreliable on a 7.5MHz SPI bus,
7 so reduce the default frequency to 6MHz.
9 See: https://github.com/raspberrypi/linux/issues/1151
11 arch/arm/boot/dts/overlays/README | 2 +-
12 arch/arm/boot/dts/overlays/at86rf233-overlay.dts | 2 +-
13 2 files changed, 2 insertions(+), 2 deletions(-)
15 --- a/arch/arm/boot/dts/overlays/README
16 +++ b/arch/arm/boot/dts/overlays/README
17 @@ -178,7 +178,7 @@ Load: dtoverlay=at86rf233,<param>=<val
18 Params: interrupt GPIO used for INT (default 23)
19 reset GPIO used for Reset (default 24)
20 sleep GPIO used for Sleep (default 25)
21 - speed SPI bus speed in Hz (default 750000)
22 + speed SPI bus speed in Hz (default 6000000)
23 trim Fine tuning of the internal capacitance
24 arrays (0=+0pF, 15=+4.5pF, default 15)
26 --- a/arch/arm/boot/dts/overlays/at86rf233-overlay.dts
27 +++ b/arch/arm/boot/dts/overlays/at86rf233-overlay.dts
29 interrupts = <23 4>; /* active high */
30 reset-gpio = <&gpio 24 1>;
31 sleep-gpio = <&gpio 25 1>;
32 - spi-max-frequency = <7500000>;
33 + spi-max-frequency = <6000000>;
34 xtal-trim = /bits/ 8 <0xf>;