drivers: gnss: add a generic NMEA GNSS driver

wip

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>

drivers/gnss/CMakeLists.txt

@@ -8,3 +8,4 @@ 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_QUECTEL_LCX6G gnss_quectel_lcx6g.c)
+zephyr_library_sources_ifdef(CONFIG_GNSS_NMEA_GENERIC gnss_nmea_generic.c)

drivers/gnss/Kconfig

@@ -65,5 +65,6 @@ module-str = gnss
 source "subsys/logging/Kconfig.template.log_config"
 
 rsource "Kconfig.quectel_lcx6g"
+rsource "Kconfig.generic"
 
 endif

drivers/gnss/Kconfig.generic

@@ -0,0 +1,17 @@
+# 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 UART_INTERRUPT_DRIVEN
+	select MODEM_MODULES
+	select MODEM_BACKEND_UART
+	select MODEM_CHAT
+	select GNSS_PARSE
+	select GNSS_NMEA0183
+	select GNSS_NMEA0183_MATCH
+	help
+	  TODO

drivers/gnss/gnss_nmea_generic.c

@@ -0,0 +1,265 @@
+/*
+ * 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/pm/device.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/pm/device_runtime.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
+
+struct gnss_nmea_generic_config {
+	const struct device *uart;
+};
+
+struct gnss_nmea_generic_data {
+	struct gnss_nmea0183_match_data match_data;
+#if CONFIG_GNSS_SATELLITES
+	struct gnss_satellite satellites[24];
+#endif
+
+	/* UART backend */
+	struct modem_pipe *uart_pipe;
+	struct modem_backend_uart uart_backend;
+	uint8_t uart_backend_receive_buf[128];
+
+	/* Modem chat */
+	struct modem_chat chat;
+	uint8_t chat_receive_buf[256];
+	uint8_t chat_delimiter[2];
+	uint8_t *chat_argv[32];
+
+	/* Dynamic chat script */
+	uint8_t dynamic_match_buf[32];
+	uint8_t dynamic_separators_buf[2];
+	uint8_t dynamic_request_buf[32];
+	struct modem_chat_match dynamic_match;
+	struct modem_chat_script_chat dynamic_script_chat;
+	struct modem_chat_script dynamic_script;
+
+	struct k_spinlock lock;
+};
+
+#define MODEM_CHAT_SCRIPT_NO_ABORT_DEFINE(_sym, _script_chats, _callback, _timeout)             \
+	static struct modem_chat_script _sym = {                                                \
+		.name = #_sym,                                                                  \
+		.script_chats = _script_chats,                                                  \
+		.script_chats_size = ARRAY_SIZE(_script_chats),                                 \
+		.abort_matches = NULL,                                                          \
+		.abort_matches_size = 0,                                                        \
+		.callback = _callback,                                                          \
+		.timeout = _timeout,                                                            \
+	}
+
+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;
+}
+
+#ifdef CONFIG_PM_DEVICE
+static int gnss_nmea_generic_suspend(const struct device *dev)
+{
+	return 0;
+}
+
+static int gnss_nmea_generic_turn_off(const struct device *dev)
+{
+	struct gnss_nmea_generic_data *data = dev->data;
+
+	return modem_pipe_close(data->uart_pipe);
+}
+
+static int gnss_nmea_generic_pm_action(const struct device *dev, enum pm_device_action action)
+{
+	struct gnss_nmea_generic_data *data = dev->data;
+	k_spinlock_key_t key;
+	int ret = -ENOTSUP;
+
+	key = k_spin_lock(&data->lock);
+
+	switch (action) {
+	case PM_DEVICE_ACTION_SUSPEND:
+		ret = gnss_nmea_generic_suspend(dev);
+		break;
+
+	case PM_DEVICE_ACTION_RESUME:
+		ret = gnss_nmea_generic_resume(dev);
+		break;
+
+	case PM_DEVICE_ACTION_TURN_ON:
+		ret = 0;
+		break;
+
+	case PM_DEVICE_ACTION_TURN_OFF:
+		ret = gnss_nmea_generic_turn_off(dev);
+		break;
+
+	default:
+		break;
+	}
+
+	k_spin_unlock(&data->lock, key);
+	return ret;
+}
+#endif /* CONFIG_PM_DEVICE */
+
+static struct gnss_driver_api gnss_api = {
+};
+
+static int gnss_nmea_generic_init_nmea0183_match(const struct device *dev)
+{
+	struct gnss_nmea_generic_data *data = dev->data;
+
+	const struct gnss_nmea0183_match_config config = {
+		.gnss = dev,
+#if CONFIG_GNSS_SATELLITES
+		.satellites = data->satellites,
+		.satellites_size = ARRAY_SIZE(data->satellites),
+#endif
+		.timeout_ms = 200,
+	};
+
+	return gnss_nmea0183_match_init(&data->match_data, &config);
+}
+
+static void gnss_nmea_generic_init_pipe(const struct device *dev)
+{
+	const struct gnss_nmea_generic_config *config = dev->config;
+	struct gnss_nmea_generic_data *data = dev->data;
+
+	const struct modem_backend_uart_config uart_backend_config = {
+		.uart = config->uart,
+		.receive_buf = data->uart_backend_receive_buf,
+		.receive_buf_size = ARRAY_SIZE(data->uart_backend_receive_buf),
+	};
+
+	data->uart_pipe = modem_backend_uart_init(&data->uart_backend, &uart_backend_config);
+}
+
+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 = ARRAY_SIZE(data->chat_receive_buf),
+		.delimiter = data->chat_delimiter,
+		.delimiter_size = ARRAY_SIZE(data->chat_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 void gnss_nmea_generic_init_dynamic_script(const struct device *dev)
+{
+	struct gnss_nmea_generic_data *data = dev->data;
+
+	data->dynamic_match.match = data->dynamic_match_buf;
+	data->dynamic_match.separators = data->dynamic_separators_buf;
+	data->dynamic_match.separators_size = sizeof(data->dynamic_separators_buf);
+	data->dynamic_match.wildcards = false;
+	data->dynamic_match.partial = false;
+
+	data->dynamic_script_chat.request = data->dynamic_request_buf;
+	data->dynamic_script_chat.response_matches = &data->dynamic_match;
+	data->dynamic_script_chat.response_matches_size = 1;
+	data->dynamic_script_chat.timeout = 0;
+
+	data->dynamic_script.name = "pair";
+	data->dynamic_script.script_chats = &data->dynamic_script_chat;
+	data->dynamic_script.script_chats_size = 1;
+	data->dynamic_script.abort_matches = NULL;
+	data->dynamic_script.abort_matches_size = 0;
+	data->dynamic_script.callback = NULL;
+	data->dynamic_script.timeout = 10;
+}
+
+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;
+	}
+
+	gnss_nmea_generic_init_dynamic_script(dev);
+
+#ifdef CONFIG_PM_DEVICE
+	pm_device_init_suspended(dev);
+#else
+	ret = gnss_nmea_generic_resume(dev);
+#endif
+	return ret;
+}
+
+#define GNSS_NMEA_GENERIC(inst)								\
+	static struct gnss_nmea_generic_config gnss_nmea_generic_cfg_##inst = {		\
+		.uart = DEVICE_DT_GET(DT_INST_BUS(inst)),				\
+	};										\
+											\
+	static struct gnss_nmea_generic_data gnss_nmea_generic_data_##inst = {		\
+		.chat_delimiter = {'\r', '\n'},						\
+		.dynamic_separators_buf = {',', '*'},					\
+	};										\
+											\
+	PM_DEVICE_DT_INST_DEFINE(inst, gnss_nmea_generic_pm_action);			\
+											\
+	DEVICE_DT_INST_DEFINE(inst, gnss_nmea_generic_init, PM_DEVICE_DT_INST_GET(inst),\
+			      &gnss_nmea_generic_data_##inst,				\
+			      &gnss_nmea_generic_cfg_##inst,				\
+			      POST_KERNEL, 99, &gnss_api);
+
+DT_INST_FOREACH_STATUS_OKAY(GNSS_NMEA_GENERIC)

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

@@ -0,0 +1,9 @@
+# Copyright 2023 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+description: Generic GNSS NMEA receiver
+
+compatible: "gnss-nmea-generic"
+
+include:
+  - uart-device.yaml