target/linux/brcm2708/patches-4.4/0123-BCM270X_DT-Add-the-sdtweak-overlay-for-tuning-sdhost.patch

   1 From 22c2725b4321128985d9780152d85a8dd1ace706 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Mon, 4 Jan 2016 14:42:17 +0000
   4 Subject: [PATCH] BCM270X_DT: Add the sdtweak overlay, for tuning sdhost
   5
   6 The sdhost overlay declares the sdhost interface and allows parameters
   7 to be set. This is overkill for situations where the user just wants to
   8 tweak the parameters of a pre-declared sdhost interface, so create an
   9 sdtweak overlay that does just that.
  10 ---
  11  arch/arm/boot/dts/overlays/Makefile            |  1 +
  12  arch/arm/boot/dts/overlays/README              | 14 ++++++++++++++
  13  arch/arm/boot/dts/overlays/sdtweak-overlay.dts | 21 +++++++++++++++++++++
  14  3 files changed, 36 insertions(+)
  15  create mode 100644 arch/arm/boot/dts/overlays/sdtweak-overlay.dts
  16
  17 --- a/arch/arm/boot/dts/overlays/Makefile
  18 +++ b/arch/arm/boot/dts/overlays/Makefile
  19 @@ -53,6 +53,7 @@ dtb-$(RPI_DT_OVERLAYS) += rpi-proto-over
  20  dtb-$(RPI_DT_OVERLAYS) += rpi-sense-overlay.dtb
  21  dtb-$(RPI_DT_OVERLAYS) += sdhost-overlay.dtb
  22  dtb-$(RPI_DT_OVERLAYS) += sdio-overlay.dtb
  23 +dtb-$(RPI_DT_OVERLAYS) += sdtweak-overlay.dtb
  24  dtb-$(RPI_DT_OVERLAYS) += smi-dev-overlay.dtb
  25  dtb-$(RPI_DT_OVERLAYS) += smi-nand-overlay.dtb
  26  dtb-$(RPI_DT_OVERLAYS) += smi-overlay.dtb
  27 --- a/arch/arm/boot/dts/overlays/README
  28 +++ b/arch/arm/boot/dts/overlays/README
  29 @@ -635,6 +635,20 @@ Params: overclock_50             Clock (
  30                                   (default on: polling once at boot-time)
  31
  32
  33 +Name:   sdtweak
  34 +Info:   Tunes the bcm2835-sdhost SD/MMC driver
  35 +Load:   dtoverlay=sdtweak,<param>=<val>
  36 +Params: overclock_50             Clock (in MHz) to use when the MMC framework
  37 +                                 requests 50MHz
  38 +
  39 +        force_pio                Disable DMA support (default off)
  40 +
  41 +        pio_limit                Number of blocks above which to use DMA
  42 +                                 (default 1)
  43 +
  44 +        debug                    Enable debug output (default off)
  45 +
  46 +
  47  Name:   smi
  48  Info:   Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
  49  Load:   dtoverlay=smi
  50 --- /dev/null
  51 +++ b/arch/arm/boot/dts/overlays/sdtweak-overlay.dts
  52 @@ -0,0 +1,21 @@
  53 +/dts-v1/;
  54 +/plugin/;
  55 +
  56 +/{
  57 +       compatible = "brcm,bcm2708";
  58 +
  59 +       fragment@0 {
  60 +               target = <&sdhost>;
  61 +               frag1: __overlay__ {
  62 +                       brcm,overclock-50 = <0>;
  63 +                       brcm,pio-limit = <1>;
  64 +               };
  65 +       };
  66 +
  67 +       __overrides__ {
  68 +               overclock_50     = <&frag1>,"brcm,overclock-50:0";
  69 +               force_pio        = <&frag1>,"brcm,force-pio?";
  70 +               pio_limit        = <&frag1>,"brcm,pio-limit:0";
  71 +               debug            = <&frag1>,"brcm,debug?";
  72 +       };
  73 +};