target/linux/brcm2708/patches-4.1/0201-BCM270X_DT-Reduce-default-at86rf233-SPI-frequency.patch

   1 From 6d67bc40a1f5236fb00c503ab631819939efc01d 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 201/222] BCM270X_DT: Reduce default at86rf233 SPI frequency
   5
   6 The AT86RF233 has been found to be unreliable on a 7.5MHz SPI bus,
   7 so reduce the default frequency to 6MHz.
   8
   9 See: https://github.com/raspberrypi/linux/issues/1151
  10 ---
  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(-)
  14
  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)
  25
  26 --- a/arch/arm/boot/dts/overlays/at86rf233-overlay.dts
  27 +++ b/arch/arm/boot/dts/overlays/at86rf233-overlay.dts
  28 @@ -25,7 +25,7 @@
  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>;
  35                         };
  36                 };