gl-puli-mcu: add GL.iNet GL-XE300 (Puli) power monitoring daemon

Signed-off-by: Nuno Goncalves <nunojpg@gmail.com>

utils/gl-puli-mcu/Makefile

@@ -0,0 +1,33 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=gl-puli-mcu
+PKG_VERSION:=1
+PKG_RELEASE:=$(AUTORELEASE)
+
+PKG_MAINTAINER:=Nuno Goncalves <nunojpg@gmail.com>
+PKG_LICENSE:=GPL-3.0-or-later
+
+include $(INCLUDE_DIR)/package.mk
+include $(INCLUDE_DIR)/cmake.mk
+
+define Package/gl-puli-mcu
+  SECTION:=utils
+  CATEGORY:=Utilities
+  TITLE:=GL.iNet GL-XE300 (Puli) power monitoring support
+  DEPENDS:=+kmod-usb-serial-ch341 +libubus +libubox
+endef
+
+define Package/gl-puli-mcu/description
+  Interfaces with GL-XE300 (Puli) power monitoring MCU over
+  a USB to UART adapter present on the device and provides
+  battery SOC, temperature, charging state and cycle count at
+  ubus battery/info.
+endef
+
+define Package/gl-puli-mcu/install
+	$(CP) ./files/* $(1)/
+	$(INSTALL_DIR) $(1)/usr/sbin
+	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/gl-puli-mcu $(1)/usr/sbin/
+endef
+
+$(eval $(call BuildPackage,gl-puli-mcu))

utils/gl-puli-mcu/files/etc/init.d/gl-puli-mcu

@@ -0,0 +1,13 @@
+#!/bin/sh /etc/rc.common
+
+START=99
+USE_PROCD=1
+
+start_service() {
+	procd_open_instance
+	procd_set_param command /usr/sbin/gl-puli-mcu
+	procd_set_param respawn
+	procd_set_param stdout 1
+	procd_set_param stderr 1
+	procd_close_instance
+}

utils/gl-puli-mcu/src/CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.12)
+PROJECT(gl-puli-mcu C)
+ADD_DEFINITIONS(-Os -ggdb -Wall --std=gnu17 -Wmissing-declarations)
+SET(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
+ADD_EXECUTABLE(gl-puli-mcu gl-puli-mcu.c)
+TARGET_LINK_LIBRARIES(gl-puli-mcu ubox ubus ${CMAKE_DL_LIBS})
+INSTALL(TARGETS gl-puli-mcu RUNTIME DESTINATION sbin)

utils/gl-puli-mcu/src/gl-puli-mcu.c

@@ -0,0 +1,214 @@
+/*
+ *   This program is free software; 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, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
+ *
+ *   Copyright (C) 2014 John Crispin <blogic@openwrt.org>
+ *   Copyright (C) 2021 Nuno Goncalves <nunojpg@gmail.com>
+ */
+
+#include <fcntl.h>
+#include <termios.h>
+
+#include <libubox/ulog.h>
+#include <libubox/ustream.h>
+#include <libubox/utils.h>
+#include <libubox/uloop.h>
+#include <libubus.h>
+
+static struct ustream_fd stream;
+static struct ubus_auto_conn conn;
+static struct blob_buf b;
+
+struct Battery
+{
+	float temperature;
+	uint16_t cycles;
+	uint8_t soc;
+	bool charging;
+	bool set;
+} battery;
+
+static bool
+process(char *read)
+{
+	if (read[0] != '{' ||
+		read[1] != 'O' ||
+		read[2] != 'K' ||
+		read[3] != '}' ||
+		read[4] != ',')
+		return false;
+	const char *from = read + 5;
+	char *to;
+	battery.soc = strtoul(from, &to, 10);
+	if (from == to)
+		return false;
+	from = to + 1;
+	battery.temperature = strtoul(from, &to, 10) / 10.0f;
+	if (from == to)
+		return false;
+	if (to[0] != ',' || (to[1] != '0' && to[1] != '1') || to[2] != ',')
+		return false;
+	battery.charging = to[1] == '1';
+	from = to + 3;
+	battery.cycles = strtoul(from, &to, 10);
+	if (from == to)
+		return false;
+	return true;
+}
+
+static int
+consume(struct ustream *s, char **a)
+{
+	char *eol = strstr(*a, "\n");
+
+	if (!eol)
+		return -1;
+
+	*eol++ = '\0';
+
+	battery.set = process(*a);
+	if (!battery.set)
+		ULOG_ERR("failed to parse message from serial: %s", a);
+
+	ustream_consume(s, eol - *a);
+	*a = eol;
+
+	return 0;
+}
+
+static void
+msg_cb(struct ustream *s, int bytes)
+{
+	int len;
+	char *a = ustream_get_read_buf(s, &len);
+
+	while (!consume(s, &a))
+		;
+}
+
+static void
+notify_cb(struct ustream *s)
+{
+	if (!s->eof)
+		return;
+
+	ULOG_ERR("tty error, shutting down\n");
+	exit(-1);
+}
+
+static int
+serial_open(char *dev)
+{
+	const int tty = open(dev, O_RDWR | O_NOCTTY | O_NONBLOCK);
+	if (tty < 0)
+	{
+		ULOG_ERR("%s: device open failed: %s\n", dev, strerror(errno));
+		return -1;
+	}
+
+	struct termios config;
+	tcgetattr(tty, &config);
+	cfmakeraw(&config);
+	cfsetispeed(&config, B9600);
+	cfsetospeed(&config, B9600);
+	tcsetattr(tty, TCSANOW, &config);
+
+	stream.stream.string_data = true;
+	stream.stream.notify_read = msg_cb;
+	stream.stream.notify_state = notify_cb;
+
+	ustream_fd_init(&stream, tty);
+
+	tcflush(tty, TCIFLUSH);
+
+	return 0;
+}
+
+static struct uloop_timeout serial_query_timer;
+static void
+serial_query_handler(struct uloop_timeout *timeout)
+{
+	const char cmd[] = "{ \"mcu_status\": \"1\" }\n";
+	const unsigned cmd_len = sizeof(cmd) - 1;
+	ustream_write(&stream.stream, cmd, cmd_len, false);
+	uloop_timeout_set(&serial_query_timer, 3000); // timeout in 3 sec
+	uloop_timeout_add(timeout);
+}
+
+static int
+battery_info(struct ubus_context *ctx, struct ubus_object *obj,
+			 struct ubus_request_data *req, const char *method,
+			 struct blob_attr *msg)
+{
+	blob_buf_init(&b, 0);
+
+	if (!battery.set)
+	{
+		blobmsg_add_u8(&b, "error", 1);
+	}
+	else
+	{
+		blobmsg_add_u16(&b, "soc", battery.soc);
+		blobmsg_add_u8(&b, "charging", battery.charging);
+		blobmsg_add_double(&b, "temperature", battery.temperature);
+		blobmsg_add_u16(&b, "cycles", battery.cycles);
+	}
+	ubus_send_reply(ctx, req, b.head);
+
+	return UBUS_STATUS_OK;
+}
+
+static const struct ubus_method battery_methods[] = {
+	UBUS_METHOD_NOARG("info", battery_info),
+};
+
+static struct ubus_object_type battery_object_type =
+	UBUS_OBJECT_TYPE("battery", battery_methods);
+
+static struct ubus_object battery_object = {
+	.name = "battery",
+	.type = &battery_object_type,
+	.methods = battery_methods,
+	.n_methods = ARRAY_SIZE(battery_methods),
+};
+
+static void
+ubus_connect_handler(struct ubus_context *ctx)
+{
+	int ret;
+
+	ret = ubus_add_object(ctx, &battery_object);
+	if (ret)
+		fprintf(stderr, "Failed to add object: %s\n", ubus_strerror(ret));
+}
+
+int
+main(int argc, char **argv)
+{
+
+	uloop_init();
+	conn.path = NULL;
+	conn.cb = ubus_connect_handler;
+	ubus_auto_connect(&conn);
+
+	if (serial_open("/dev/ttyUSB0") < 0)
+		return -1;
+
+	serial_query_timer.cb = serial_query_handler;
+	serial_query_handler(&serial_query_timer);
+	uloop_run();
+	uloop_done();
+
+	return 0;
+}