modem: hl78xx: Add AT Shell support

Adds AT shell support for the HL78xx modem driver, enabling developers to send AT commands directly through the Zephyr shell for testing and debugging purposes.

Signed-off-by: Zafer SEN <[email protected]>

Author: zafersn

drivers/modem/hl78xx/CMakeLists.txt

@@ -13,6 +13,11 @@ zephyr_library_sources(
     hl78xx_apis.c
 )
 
+zephyr_library_sources_ifdef(
+    CONFIG_MODEM_HL78XX_AT_SHELL
+    hl78xx_at_shell.c
+)
+
 add_subdirectory_ifdef(CONFIG_HL78XX_EVT_MONITOR hl78xx_evt_monitor)
 
 zephyr_library_include_directories(

drivers/modem/hl78xx/hl78xx_at_shell.c

@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2025 Netfeasa Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/shell/shell.h>
+#include <zephyr/modem/chat.h>
+#include <zephyr/modem/pipelink.h>
+#include <zephyr/sys/atomic.h>
+#include <hl78xx.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(modem_at_shell, CONFIG_MODEM_LOG_LEVEL);
+
+#define AT_SHELL_STATE_SCRIPT_RUNNING_BIT 1
+
+const static struct device *modem = DEVICE_DT_GET(DT_ALIAS(modem));
+static struct modem_chat *at_shell_chat;
+static uint8_t at_shell_request_buf[CONFIG_MODEM_AT_SHELL_COMMAND_MAX_SIZE];
+static struct modem_chat_script_chat at_shell_script_chat[1];
+static struct modem_chat_match at_shell_script_chat_matches[2];
+static uint8_t at_shell_match_buf[CONFIG_MODEM_AT_SHELL_RESPONSE_MAX_SIZE];
+static const struct shell *at_shell_active_shell;
+static atomic_t at_shell_state;
+
+static void at_shell_print_any_match(struct modem_chat *chat, char **argv, uint16_t argc,
+				     void *user_data)
+{
+	if (at_shell_active_shell == NULL) {
+		return;
+	}
+
+	if (argc != 2) {
+		return;
+	}
+
+	shell_print(at_shell_active_shell, "%s", argv[1]);
+}
+
+static void at_shell_print_match(struct modem_chat *chat, char **argv, uint16_t argc,
+				 void *user_data)
+{
+	if (at_shell_active_shell == NULL) {
+		return;
+	}
+
+	if (argc != 1) {
+		return;
+	}
+
+	shell_print(at_shell_active_shell, "%s", argv[0]);
+}
+
+MODEM_CHAT_MATCHES_DEFINE(at_shell_abort_matches,
+			  MODEM_CHAT_MATCH("+CME ERROR:", "", at_shell_print_match),
+			  MODEM_CHAT_MATCH("ERROR", "", at_shell_print_match));
+
+static void at_shell_script_callback(struct modem_chat *chat, enum modem_chat_script_result result,
+				     void *user_data)
+{
+	atomic_clear_bit(&at_shell_state, AT_SHELL_STATE_SCRIPT_RUNNING_BIT);
+}
+
+MODEM_CHAT_SCRIPT_DEFINE(at_shell_script, at_shell_script_chat, at_shell_abort_matches,
+			 at_shell_script_callback, CONFIG_MODEM_AT_SHELL_RESPONSE_TIMEOUT_MS);
+
+static void at_shell_init_script_chat(void)
+{
+	/* Match anything except the expected response without progressing script */
+	modem_chat_match_init(&at_shell_script_chat_matches[0]);
+	modem_chat_match_set_match(&at_shell_script_chat_matches[0], "");
+	modem_chat_match_set_separators(&at_shell_script_chat_matches[0], "");
+	modem_chat_match_set_callback(&at_shell_script_chat_matches[0], at_shell_print_any_match);
+	modem_chat_match_set_partial(&at_shell_script_chat_matches[0], true);
+	modem_chat_match_enable_wildcards(&at_shell_script_chat_matches[0], false);
+
+	/* Match the expected response and terminate script */
+	modem_chat_match_init(&at_shell_script_chat_matches[1]);
+	modem_chat_match_set_match(&at_shell_script_chat_matches[1], "");
+	modem_chat_match_set_separators(&at_shell_script_chat_matches[1], "");
+	modem_chat_match_set_callback(&at_shell_script_chat_matches[1], at_shell_print_match);
+	modem_chat_match_set_partial(&at_shell_script_chat_matches[1], false);
+	modem_chat_match_enable_wildcards(&at_shell_script_chat_matches[1], false);
+
+	modem_chat_script_chat_init(at_shell_script_chat);
+	modem_chat_script_chat_set_response_matches(at_shell_script_chat,
+						    at_shell_script_chat_matches,
+						    ARRAY_SIZE(at_shell_script_chat_matches));
+	modem_chat_script_chat_set_timeout(at_shell_script_chat,
+					   CONFIG_MODEM_AT_SHELL_RESPONSE_TIMEOUT_MS);
+}
+
+static int hl78xx_at_shell_init(void)
+{
+	struct hl78xx_data *data = NULL;
+
+	if (device_is_ready(modem) == false) {
+		LOG_ERR("%d, %s Device %s is not ready", __LINE__, __func__, modem->name);
+	}
+	data = (struct hl78xx_data *)modem->data;
+	if (data == NULL) {
+		LOG_ERR("%d, %s Modem data is NULL", __LINE__, __func__);
+		return -EINVAL;
+	}
+	at_shell_chat = &data->chat;
+
+	at_shell_init_script_chat();
+	return 0;
+}
+
+static int at_shell_cmd_handler(const struct shell *sh, size_t argc, char **argv)
+{
+	int ret;
+
+	if (argc < 2) {
+		return -EINVAL;
+	}
+	if (atomic_test_and_set_bit(&at_shell_state, AT_SHELL_STATE_SCRIPT_RUNNING_BIT)) {
+		shell_error(sh, "script is already running");
+		return -EBUSY;
+	}
+	strncpy(at_shell_request_buf, argv[1], sizeof(at_shell_request_buf) - 1);
+	ret = modem_chat_script_chat_set_request(at_shell_script_chat, at_shell_request_buf);
+	if (ret < 0) {
+		return -EINVAL;
+	}
+	if (argc == 3) {
+		strncpy(at_shell_match_buf, argv[2], sizeof(at_shell_match_buf) - 1);
+	} else {
+		strncpy(at_shell_match_buf, "OK", sizeof(at_shell_match_buf) - 1);
+	}
+	ret = modem_chat_match_set_match(&at_shell_script_chat_matches[1], at_shell_match_buf);
+	if (ret < 0) {
+		return -EINVAL;
+	}
+	at_shell_active_shell = sh;
+	ret = modem_chat_run_script_async(at_shell_chat, &at_shell_script);
+	if (ret < 0) {
+		shell_error(sh, "failed to start script");
+		atomic_clear_bit(&at_shell_state, AT_SHELL_STATE_SCRIPT_RUNNING_BIT);
+	}
+	return ret;
+}
+
+SHELL_STATIC_SUBCMD_SET_CREATE(modem_sub_cmds,
+			       SHELL_CMD_ARG(at, NULL, "at <command> <response>",
+					     at_shell_cmd_handler, 1, 2),
+			       SHELL_SUBCMD_SET_END);
+
+SHELL_CMD_REGISTER(modem, &modem_sub_cmds, "Modem commands", NULL);
+
+SYS_INIT(hl78xx_at_shell_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);