103 lines
3.8 KiB
Diff
103 lines
3.8 KiB
Diff
From 9444edfa8b5b18f8727b82853dd50345a400a316 Mon Sep 17 00:00:00 2001
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From: Phil Elwell <phil@raspberrypi.com>
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Date: Thu, 22 Oct 2020 17:11:12 +0100
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Subject: [PATCH] overlays: Add MAX31856 support to maxtherm overlay
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Extend the maxtherm overlay with support for the MAX31856.
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The driver reads the thermocouple type from a property, which is much
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more civilised.
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See: https://github.com/raspberrypi/linux/issues/3915
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Signed-off-by: Phil Elwell <phil@raspberrypi.com>
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---
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arch/arm/boot/dts/overlays/README | 18 ++++++++++++-----
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.../boot/dts/overlays/maxtherm-overlay.dts | 20 +++++++++++++++++++
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2 files changed, 33 insertions(+), 5 deletions(-)
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--- a/arch/arm/boot/dts/overlays/README
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+++ b/arch/arm/boot/dts/overlays/README
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@@ -1666,20 +1666,19 @@ Params: no-sdmode Driver d
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Name: maxtherm
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-Info: Configure a MAX6675 or MAX31855 thermocouple as an IIO device.
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+Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
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For devices on spi1 or spi2, the interfaces should be enabled
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with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
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The overlay expects to disable the relevant spidev node, so also using
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e.g. cs0_spidev=off is unnecessary.
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- Note: with the 5.7 kernel (and later) there will also be
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- overlays for MAX31855E, MAX31855J, MAX31855K,
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- MAX31885N, MAX31855R, MAX31855S and MAX31855T.
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-
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Example:
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MAX31855 on /dev/spidev0.0
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dtoverlay=maxtherm,spi0-0,max31855
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+ MAX31856 using a type J thermocouple on /dev/spidev2.1
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+ dtoverlay=spi2-2cs
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+ dtoverlay=maxtherm,spi2-1,max31856,type_j
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Load: dtoverlay=maxtherm,<param>=<val>
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Params: spi<n>-<m> Configure device at spi<n>, cs<m>
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@@ -1693,6 +1692,15 @@ Params: spi<n>-<m> Configur
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max31855r Enable support for the MAX31855R
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max31855s Enable support for the MAX31855S
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max31855t Enable support for the MAX31855T
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+ max31856 Enable support for the MAX31856 (with type K)
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+ type_b Select a type B sensor for max31856
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+ type_e Select a type E sensor for max31856
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+ type_j Select a type J sensor for max31856
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+ type_k Select a type K sensor for max31856
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+ type_n Select a type N sensor for max31856
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+ type_r Select a type R sensor for max31856
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+ type_s Select a type S sensor for max31856
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+ type_t Select a type T sensor for max31856
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Name: mbed-dac
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--- a/arch/arm/boot/dts/overlays/maxtherm-overlay.dts
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+++ b/arch/arm/boot/dts/overlays/maxtherm-overlay.dts
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@@ -5,6 +5,8 @@
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/dts-v1/;
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/plugin/;
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+#include <dt-bindings/iio/temperature/thermocouple.h>
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+
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/ {
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compatible = "brcm,bcm2835";
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@@ -128,6 +130,15 @@
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};
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};
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+ fragment@16 {
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+ target = <&max>;
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+ __dormant__ {
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+ compatible = "maxim,max31856";
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+ spi-cpha;
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+ thermocouple-type = <THERMOCOUPLE_TYPE_K>;
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+ };
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+ };
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+
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__overrides__ {
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spi0-0 = <0>, "+0",
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<&maxfrag>,"target:0=",<&spi0>,
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@@ -162,5 +173,14 @@
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max31855r = <0>,"+13";
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max31855s = <0>,"+14";
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max31855t = <0>,"+15";
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+ max31856 = <0>,"+16";
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+ type_b = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_B>;
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+ type_e = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_E>;
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+ type_j = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_J>;
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+ type_k = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_K>;
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+ type_n = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_N>;
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+ type_r = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_R>;
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+ type_s = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_S>;
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+ type_t = <&max>,"thermocouple-type:0=",<THERMOCOUPLE_TYPE_T>;
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};
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};
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