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From 37f172b47784a4debc62cb71974eac303031e69c Mon Sep 17 00:00:00 2001
From: pjx3 <pjx3@users.noreply.github.com>
Date: Sun, 8 Aug 2021 20:09:46 +0100
Subject: [PATCH] overlays: Add midi-uart{2345}-overlay.dts
Added overlays for enabling MIDI baudrates on additional UARTs
Signed-off-by: Pete Marshall <petemarshall303@gmail.com>
---
arch/arm/boot/dts/overlays/Makefile | 4 ++
arch/arm/boot/dts/overlays/README | 28 ++++++++++++++
.../boot/dts/overlays/midi-uart2-overlay.dts | 37 ++++++++++++++++++
.../boot/dts/overlays/midi-uart3-overlay.dts | 38 +++++++++++++++++++
.../boot/dts/overlays/midi-uart4-overlay.dts | 38 +++++++++++++++++++
.../boot/dts/overlays/midi-uart5-overlay.dts | 38 +++++++++++++++++++
6 files changed, 183 insertions(+)
create mode 100644 arch/arm/boot/dts/overlays/midi-uart2-overlay.dts
create mode 100644 arch/arm/boot/dts/overlays/midi-uart3-overlay.dts
create mode 100644 arch/arm/boot/dts/overlays/midi-uart4-overlay.dts
create mode 100644 arch/arm/boot/dts/overlays/midi-uart5-overlay.dts
--- a/arch/arm/boot/dts/overlays/Makefile
+++ b/arch/arm/boot/dts/overlays/Makefile
@@ -123,6 +123,10 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
merus-amp.dtbo \
midi-uart0.dtbo \
midi-uart1.dtbo \
+ midi-uart2.dtbo \
+ midi-uart3.dtbo \
+ midi-uart4.dtbo \
+ midi-uart5.dtbo \
minipitft13.dtbo \
miniuart-bt.dtbo \
mmc.dtbo \
--- a/arch/arm/boot/dts/overlays/README
+++ b/arch/arm/boot/dts/overlays/README
@@ -2088,6 +2088,34 @@ Load: dtoverlay=midi-uart1
Params: <None>
+Name: midi-uart2
+Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
+ 31.25kbaud, the frequency required for MIDI
+Load: dtoverlay=midi-uart2
+Params: <None>
+
+
+Name: midi-uart3
+Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
+ 31.25kbaud, the frequency required for MIDI
+Load: dtoverlay=midi-uart3
+Params: <None>
+
+
+Name: midi-uart4
+Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
+ 31.25kbaud, the frequency required for MIDI
+Load: dtoverlay=midi-uart4
+Params: <None>
+
+
+Name: midi-uart5
+Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
+ 31.25kbaud, the frequency required for MIDI
+Load: dtoverlay=midi-uart5
+Params: <None>
+
+
Name: minipitft13
Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
Load: dtoverlay=minipitft13,<param>=<val>
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/midi-uart2-overlay.dts
@@ -0,0 +1,37 @@
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/clock/bcm2835.h>
+
+/*
+ * Fake a higher clock rate to get a larger divisor, and thereby a lower
+ * baudrate. The real clock is 48MHz, which we scale so that requesting
+ * 38.4kHz results in an actual 31.25kHz.
+ *
+ * 48000000*38400/31250 = 58982400
+ */
+
+/{
+ compatible = "brcm,bcm2835";
+
+ fragment@0 {
+ target-path = "/";
+ __overlay__ {
+ midi_clk: midi_clk2 {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-output-names = "uart2_pclk";
+ clock-frequency = <58982400>;
+ };
+ };
+ };
+
+ fragment@1 {
+ target = <&uart2>;
+ __overlay__ {
+ clocks = <&midi_clk>,
+ <&clocks BCM2835_CLOCK_VPU>;
+ };
+ };
+};
+
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/midi-uart3-overlay.dts
@@ -0,0 +1,38 @@
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/clock/bcm2835.h>
+
+/*
+ * Fake a higher clock rate to get a larger divisor, and thereby a lower
+ * baudrate. The real clock is 48MHz, which we scale so that requesting
+ * 38.4kHz results in an actual 31.25kHz.
+ *
+ * 48000000*38400/31250 = 58982400
+ */
+
+/{
+ compatible = "brcm,bcm2835";
+
+ fragment@0 {
+ target-path = "/";
+ __overlay__ {
+ midi_clk: midi_clk3 {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-output-names = "uart3_pclk";
+ clock-frequency = <58982400>;
+ };
+ };
+ };
+
+ fragment@1 {
+ target = <&uart3>;
+ __overlay__ {
+ clocks = <&midi_clk>,
+ <&clocks BCM2835_CLOCK_VPU>;
+ };
+ };
+};
+
+
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/midi-uart4-overlay.dts
@@ -0,0 +1,38 @@
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/clock/bcm2835.h>
+
+/*
+ * Fake a higher clock rate to get a larger divisor, and thereby a lower
+ * baudrate. The real clock is 48MHz, which we scale so that requesting
+ * 38.4kHz results in an actual 31.25kHz.
+ *
+ * 48000000*38400/31250 = 58982400
+ */
+
+/{
+ compatible = "brcm,bcm2835";
+
+ fragment@0 {
+ target-path = "/";
+ __overlay__ {
+ midi_clk: midi_clk4 {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-output-names = "uart4_pclk";
+ clock-frequency = <58982400>;
+ };
+ };
+ };
+
+ fragment@1 {
+ target = <&uart4>;
+ __overlay__ {
+ clocks = <&midi_clk>,
+ <&clocks BCM2835_CLOCK_VPU>;
+ };
+ };
+};
+
+
--- /dev/null
+++ b/arch/arm/boot/dts/overlays/midi-uart5-overlay.dts
@@ -0,0 +1,38 @@
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/clock/bcm2835.h>
+
+/*
+ * Fake a higher clock rate to get a larger divisor, and thereby a lower
+ * baudrate. The real clock is 48MHz, which we scale so that requesting
+ * 38.4kHz results in an actual 31.25kHz.
+ *
+ * 48000000*38400/31250 = 58982400
+ */
+
+/{
+ compatible = "brcm,bcm2835";
+
+ fragment@0 {
+ target-path = "/";
+ __overlay__ {
+ midi_clk: midi_clk5 {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-output-names = "uart5_pclk";
+ clock-frequency = <58982400>;
+ };
+ };
+ };
+
+ fragment@1 {
+ target = <&uart5>;
+ __overlay__ {
+ clocks = <&midi_clk>,
+ <&clocks BCM2835_CLOCK_VPU>;
+ };
+ };
+};
+
+
|
