drivers: gnss: add a generic NMEA GNSS driver

MAINTAINERS.yml

@@ -1101,6 +1101,7 @@ Release Notes:
     - doc/hardware/peripherals/gnss.rst
     - drivers/gnss/
     - include/zephyr/drivers/gnss.h
+    - tests/drivers/build_all/gnss/
     - tests/drivers/gnss/
   labels:
     - "area: GNSS"

drivers/gnss/CMakeLists.txt

@@ -7,4 +7,5 @@ zephyr_library_sources_ifdef(CONFIG_GNSS_DUMP gnss_dump.c)
 zephyr_library_sources_ifdef(CONFIG_GNSS_PARSE gnss_parse.c)
 zephyr_library_sources_ifdef(CONFIG_GNSS_NMEA0183 gnss_nmea0183.c)
 zephyr_library_sources_ifdef(CONFIG_GNSS_NMEA0183_MATCH gnss_nmea0183_match.c)
+zephyr_library_sources_ifdef(CONFIG_GNSS_NMEA_GENERIC gnss_nmea_generic.c)
 zephyr_library_sources_ifdef(CONFIG_GNSS_QUECTEL_LCX6G gnss_quectel_lcx6g.c)

drivers/gnss/Kconfig

@@ -64,6 +64,7 @@ module = GNSS
 module-str = gnss
 source "subsys/logging/Kconfig.template.log_config"
 
+rsource "Kconfig.generic"
 rsource "Kconfig.quectel_lcx6g"
 
 endif

drivers/gnss/Kconfig.generic

@@ -0,0 +1,26 @@
+# Copyright 2023 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+config GNSS_NMEA_GENERIC
+	bool "Generic GNSS NMEA device"
+	default y
+	depends on GNSS
+	depends on DT_HAS_GNSS_NMEA_GENERIC_ENABLED
+	select MODEM_MODULES
+	select MODEM_BACKEND_UART
+	select MODEM_CHAT
+	select GNSS_PARSE
+	select GNSS_NMEA0183
+	select GNSS_NMEA0183_MATCH
+	help
+	  Generic NMEA based GNSS device.
+
+config GNSS_NMEA_GENERIC_SATELLITES_COUNT
+	int "Maximum satellite count"
+	depends on GNSS_SATELLITES
+	default 24
+	help
+	  Maximum number of satellite that the driver that can be decoded from
+	  the GNSS device. This does not affect the number of devices that the
+	  device is actually tracking, just how many of those can be reported
+	  in the satellites callback.

drivers/gnss/gnss_nmea_generic.c

@@ -0,0 +1,176 @@
+/*
+ * Copyright (c) 2023 Trackunit Corporation
+ * Copyright (c) 2023 Bjarki Arge Andreasen
+ * Copyright 2023 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/drivers/gnss.h>
+#include <zephyr/modem/chat.h>
+#include <zephyr/modem/backend/uart.h>
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/gpio.h>
+#include <string.h>
+
+#include "gnss_publish.h"
+#include "gnss_nmea0183.h"
+#include "gnss_nmea0183_match.h"
+#include "gnss_parse.h"
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(gnss_nmea_generic, CONFIG_GNSS_LOG_LEVEL);
+
+#define DT_DRV_COMPAT gnss_nmea_generic
+
+#define UART_RECV_BUF_SZ 128
+#define CHAT_RECV_BUF_SZ 256
+#define CHAT_ARGV_SZ 32
+
+struct gnss_nmea_generic_config {
+	const struct device *uart;
+	uint16_t nmea_timeout_ms;
+};
+
+struct gnss_nmea_generic_data {
+	struct gnss_nmea0183_match_data match_data;
+#if CONFIG_GNSS_SATELLITES
+	struct gnss_satellite satellites[CONFIG_GNSS_NMEA_GENERIC_SATELLITES_COUNT];
+#endif
+
+	/* UART backend */
+	struct modem_pipe *uart_pipe;
+	struct modem_backend_uart uart_backend;
+	uint8_t uart_backend_receive_buf[UART_RECV_BUF_SZ];
+
+	/* Modem chat */
+	struct modem_chat chat;
+	uint8_t chat_receive_buf[CHAT_RECV_BUF_SZ];
+	uint8_t *chat_argv[CHAT_ARGV_SZ];
+
+	struct k_spinlock lock;
+};
+
+MODEM_CHAT_MATCHES_DEFINE(unsol_matches,
+	MODEM_CHAT_MATCH_WILDCARD("$??GGA,", ",*", gnss_nmea0183_match_gga_callback),
+	MODEM_CHAT_MATCH_WILDCARD("$??RMC,", ",*", gnss_nmea0183_match_rmc_callback),
+#if CONFIG_GNSS_SATELLITES
+	MODEM_CHAT_MATCH_WILDCARD("$??GSV,", ",*", gnss_nmea0183_match_gsv_callback),
+#endif
+);
+
+static int gnss_nmea_generic_resume(const struct device *dev)
+{
+	struct gnss_nmea_generic_data *data = dev->data;
+	int ret;
+
+	ret = modem_pipe_open(data->uart_pipe);
+	if (ret < 0) {
+		return ret;
+	}
+
+	ret = modem_chat_attach(&data->chat, data->uart_pipe);
+	if (ret < 0) {
+		modem_pipe_close(data->uart_pipe);
+		return ret;
+	}
+
+	return ret;
+}
+
+static struct gnss_driver_api gnss_api = {
+};
+
+static int gnss_nmea_generic_init_nmea0183_match(const struct device *dev)
+{
+	const struct gnss_nmea_generic_config *cfg = dev->config;
+	struct gnss_nmea_generic_data *data = dev->data;
+
+	const struct gnss_nmea0183_match_config match_config = {
+		.gnss = dev,
+#if CONFIG_GNSS_SATELLITES
+		.satellites = data->satellites,
+		.satellites_size = ARRAY_SIZE(data->satellites),
+#endif
+		.timeout_ms = cfg->nmea_timeout_ms,
+	};
+
+	return gnss_nmea0183_match_init(&data->match_data, &match_config);
+}
+
+static void gnss_nmea_generic_init_pipe(const struct device *dev)
+{
+	const struct gnss_nmea_generic_config *cfg = dev->config;
+	struct gnss_nmea_generic_data *data = dev->data;
+
+	const struct modem_backend_uart_config uart_backend_config = {
+		.uart = cfg->uart,
+		.receive_buf = data->uart_backend_receive_buf,
+		.receive_buf_size = sizeof(data->uart_backend_receive_buf),
+	};
+
+	data->uart_pipe = modem_backend_uart_init(&data->uart_backend, &uart_backend_config);
+}
+
+static uint8_t gnss_nmea_generic_char_delimiter[] = {'\r', '\n'};
+
+static int gnss_nmea_generic_init_chat(const struct device *dev)
+{
+	struct gnss_nmea_generic_data *data = dev->data;
+
+	const struct modem_chat_config chat_config = {
+		.user_data = data,
+		.receive_buf = data->chat_receive_buf,
+		.receive_buf_size = sizeof(data->chat_receive_buf),
+		.delimiter = gnss_nmea_generic_char_delimiter,
+		.delimiter_size = ARRAY_SIZE(gnss_nmea_generic_char_delimiter),
+		.filter = NULL,
+		.filter_size = 0,
+		.argv = data->chat_argv,
+		.argv_size = ARRAY_SIZE(data->chat_argv),
+		.unsol_matches = unsol_matches,
+		.unsol_matches_size = ARRAY_SIZE(unsol_matches),
+		.process_timeout = K_MSEC(2),
+	};
+
+	return modem_chat_init(&data->chat, &chat_config);
+}
+
+static int gnss_nmea_generic_init(const struct device *dev)
+{
+	int ret;
+
+	ret = gnss_nmea_generic_init_nmea0183_match(dev);
+	if (ret < 0) {
+		return ret;
+	}
+
+	gnss_nmea_generic_init_pipe(dev);
+
+	ret = gnss_nmea_generic_init_chat(dev);
+	if (ret < 0) {
+		return ret;
+	}
+
+	ret = gnss_nmea_generic_resume(dev);
+	if (ret < 0) {
+		return ret;
+	}
+
+	return 0;
+}
+
+#define GNSS_NMEA_GENERIC(inst)								\
+	static struct gnss_nmea_generic_config gnss_nmea_generic_cfg_##inst = {		\
+		.uart = DEVICE_DT_GET(DT_INST_BUS(inst)),				\
+		.nmea_timeout_ms = DT_INST_PROP(inst, nmea_timeout_ms),			\
+	};										\
+											\
+	static struct gnss_nmea_generic_data gnss_nmea_generic_data_##inst;		\
+											\
+	DEVICE_DT_INST_DEFINE(inst, gnss_nmea_generic_init, NULL,			\
+			      &gnss_nmea_generic_data_##inst,				\
+			      &gnss_nmea_generic_cfg_##inst,				\
+			      POST_KERNEL, CONFIG_GNSS_INIT_PRIORITY, &gnss_api);
+
+DT_INST_FOREACH_STATUS_OKAY(GNSS_NMEA_GENERIC)

dts/bindings/gnss/gnss-nmea-generic.yaml

@@ -0,0 +1,32 @@
+# Copyright 2023 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  Generic GNSS NMEA receiver
+
+  Implement a generic NMEA based GNSS device.
+
+  Example configuration:
+
+  &uart0 {
+          current-speed = <9600>;
+          ...
+          gnss: gnss-nmea-generic {
+                  compatible = "gnss-nmea-generic";
+          };
+  };
+
+compatible: "gnss-nmea-generic"
+
+include:
+  - uart-device.yaml
+
+properties:
+  nmea-timeout-ms:
+    type: int
+    default: 500
+    description: |
+      Synchronization timeout for NMEA sentences. The NMEA parser is expecting
+      to receive a GGA and RMC sentences within this time frame to publish a
+      location data. Set accordingly to the UART datarate and location
+      reporting frequency. Defaults to 500ms if unspecified.

tests/drivers/build_all/gnss/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(build_all)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

tests/drivers/build_all/gnss/app.overlay

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	test {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+                test_uart: uart@0 {
+                        compatible = "vnd,serial";
+                        reg = <0x0 0x1000>;
+                        status = "okay";
+
+			gnss: gnss-nmea-generic {
+				compatible = "gnss-nmea-generic";
+			};
+                };
+	};
+};

tests/drivers/build_all/gnss/prj.conf

@@ -0,0 +1,3 @@
+CONFIG_SERIAL=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+CONFIG_GNSS=y

tests/drivers/build_all/gnss/src/main.c

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+int main(void)
+{
+	return 0;
+}

tests/drivers/build_all/gnss/testcase.yaml

@@ -0,0 +1,8 @@
+common:
+  tags:
+    - drivers
+    - gnss
+  build_only: true
+  platform_allow: native_sim
+tests:
+  drivers.gnss.default: {}