From: Antonio Ospite <ao2@ao2.it>
Date: Thu, 26 Jul 2018 10:56:46 +0000 (+0200)
Subject: Initial import
X-Git-Url: https://git.ao2.it/experiments/bbb-eqep2b-ao2.git/commitdiff_plain/c80f1b1f292d83b584798258b999d34fa86e936a

Initial import
---

c80f1b1f292d83b584798258b999d34fa86e936a
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..c5d4c93
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,20 @@
+PART_NUMBER = bbb-eqep2b-ao2
+VERSION = 00A0
+
+# To get the include files, clone the repository from
+# https://github.com/beagleboard/bb.org-overlays.git
+# parallel to this directory.
+
+INCLUDE_PATH = ../bb.org-overlays/include
+
+compile: $(PART_NUMBER)-$(VERSION).dtbo
+
+install: compile
+	cp $(PART_NUMBER)-$(VERSION).dtbo /lib/firmware
+
+clean:
+	rm -f *.dtbo *.dts.tmp *~
+
+%.dtbo: %.dts
+	cpp -nostdinc -undef -D__DTS__ -I$(INCLUDE_PATH) -x assembler-with-cpp -o $<.tmp $<
+	dtc -Wno-unit_address_vs_reg -O dtb -o $@ -b 0 -@ $<.tmp
diff --git a/bbb-eqep2b-ao2-00A0.dts b/bbb-eqep2b-ao2-00A0.dts
new file mode 100644
index 0000000..0eaf9e3
--- /dev/null
+++ b/bbb-eqep2b-ao2-00A0.dts
@@ -0,0 +1,88 @@
+/*
+ * Set up eQEP in a way that does not conflict with HDMI.
+ *
+ * Copyright (C) 2013  Nathaniel R. Lewis - http://nathanielrlewis.com/
+ * Copyright (C) 2018  Antonio Ospite <ao2@ao2.it>
+ *
+ * This program is free softwarejc you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/board/am335x-bbw-bbb-base.h>
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/pinctrl/am33xx.h>
+
+/ {
+	compatible = "ti,beaglebone", "ti,beaglebone-black";
+
+	// Identification.
+	part-number = "bbb-eqep2b-ao2";
+	version	    = "00A0";
+
+	// Resources this cape uses.
+	exclusive-use =
+		"P8.12",	// EQEP2A_in
+		"P8.11",	// EQEP2B_in
+		"P8.16",	// EQEP2_index
+		"P8.15",	// EQEP2_strobe
+
+		"eqep2";	// hardware ip used
+
+	fragment@0 {
+		target = <&am33xx_pinmux>;
+		__overlay__ {
+			pinctrl_eqep2: pinctrl_eqep2_pins {
+				pinctrl-single,pins = <
+					BONE_P8_12 (PIN_INPUT | MUX_MODE4)	// GPIO1_12 = EQEP2A_in
+					BONE_P8_11 (PIN_INPUT | MUX_MODE4)	// GPIO1_13 = EQEP2B_in
+					BONE_P8_16 (PIN_INPUT | MUX_MODE4)	// GPIO1_14 = EQEP2_index
+					BONE_P8_15 (PIN_INPUT | MUX_MODE4)	// GPIO1_15 = EQEP2_strobe
+					// From: https://groups.google.com/forum/#!searchin/beagleboard/eQep/beagleboard/Orp3tFcNgCc/mYacP_GkCQQJ
+				>;
+			};
+		};
+	};
+
+	fragment@1 {
+		target = <&epwmss2>;
+		__overlay__ {
+			status = "okay";
+		};
+	};
+
+	fragment@2 {
+		target = <&eqep2>;
+		__overlay__ {
+			pinctrl-names = "default";
+			pinctrl-0 = <&pinctrl_eqep2>;
+
+			count_mode = <0>;	// count_mode is not userspace op_mode
+			// 0 -> Quadrature mode, normal 90 phase offset cha & chb.
+			// 1 -> Direction mode.  cha input = clock, chb input = direction
+			// 2 -> UP count mode for frequency measurement QDIR=1, ignore direction input
+			// 3 -> DOWN count mode for frequency measurement QDIR=0, ignore direction input
+
+			swap_inputs = <0>;	// swap channel A and B? (0 - no, 1 - yes)
+			invert_qa = <1>;	// invert channel A input?
+			invert_qb = <1>;	// invert channel B input?
+			invert_qi = <0>;	// invert index input?
+			invert_qs = <0>;	// invert strobe input?
+			omit_interrupt = <0>;	// 1 -> do not install interrupt handler, 0 -> do install
+
+			status = "okay";
+		};
+	};
+};
diff --git a/eQEP-test.sh b/eQEP-test.sh
new file mode 100755
index 0000000..dd0e105
--- /dev/null
+++ b/eQEP-test.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+set -e
+
+while true;
+do
+  cat /sys/devices/platform/ocp/48304000.epwmss/48304180.eqep/position
+done