shell: Add NFC T4T shell backend

This adds the new NFC T4T shell backend.
The transport interface uses raw ISO-DEP
protocol to exchange data with a reader device.

NCSDK-22428

Signed-off-by: Kamil Gawor <Kamil.Gawor@nordicsemi.no>

Author: KAGA164

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -631,7 +631,10 @@ Common Application Framework (CAF)
 Shell libraries
 ---------------
 
-|no_changes_yet_note|
+* Added:
+
+  * The :ref:`shell_nfc_readme` library.
+    It adds shell backend using the NFC T4T ISO-DEP protocol for data exchange.
 
 Libraries for Zigbee
 --------------------

include/shell/shell_nfc.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+#ifndef SHELL_NFC_H_
+#define SHELL_NFC_H_
+
+#include <zephyr/shell/shell.h>
+
+/**
+ * @file
+ * @defgroup shell_nfc NFC shell transport
+ * @{
+ * @brief NFC shell transport API.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief This function provides a pointer to the shell NFC backend instance.
+ *
+ * The function returns a pointer to the shell NFC instance. This instance can then be
+ * used with the shell_execute_cmd function to test the behavior of the command.
+ *
+ * @returns Pointer to the shell instance.
+ */
+const struct shell *shell_backend_nfc_get_ptr(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**
+ *@}
+ */
+
+#endif /* SHELL_NFC_H_ */

subsys/shell/CMakeLists.txt

@@ -6,3 +6,4 @@
 
 zephyr_sources_ifdef(CONFIG_SHELL_BT_NUS shell_bt_nus.c)
 zephyr_sources_ifdef(CONFIG_SHELL_IPC shell_ipc.c)
+zephyr_sources_ifdef(CONFIG_SHELL_NFC shell_nfc.c)

subsys/shell/Kconfig

@@ -153,3 +153,91 @@ default-size = 10
 source "${ZEPHYR_BASE}/subsys/shell/Kconfig.template.shell_log_queue_size"
 
 endif #SHELL_IPC
+
+menuconfig SHELL_NFC
+	bool "Shell NFC transport"
+	depends on NFC_T4T_NRFXLIB
+	help
+	  Enable NFC T4T ISO-DEP transport layer for shell interface.
+
+if SHELL_NFC
+
+config SHELL_NFC_INIT_PRIORITY
+	int "Initialization priority"
+	default 0
+	range 0 99
+	help
+	  Initialization priority for NFC backend.
+
+config SHELL_NFC_BACKEND_TX_BUFFER
+	int "NFC Tx buffer size"
+	default 255
+	help
+	  Set the NFC ISO-DEP response buffer size. The response buffer size might vary on the
+	  NFC Reader device maximum supported frame size. Its size can be
+	  SHELL_NFC_BACKEND_TX_RING_BUFFER_SIZE + 1. One byte is used for a packet header.
+
+config SHELL_NFC_BACKEND_TX_RING_BUFFER_SIZE
+	int "Shell Tx ring buffer size"
+	default 254
+	help
+	  Set the shell Tx ring buffer size. It collects data from the shell and passes it to the
+	  transport interface. It can be increased to transfer data in bigger chunks. To achieve the
+	  higher data throughput, the SHELL_NFC_BACKEND_TX_BUFFER Kconfig option must be increased
+	  together with it.
+
+config SHELL_NFC_BACKEND_RX_RING_BUFFER_SIZE
+	int "Shell Rx ring buffer size"
+	default 32
+	help
+	  RX ring buffer size impacts accepted latency of handling incoming
+	  bytes by shell. If shell input is coming from the keyboard then it is
+	  usually enough if ring buffer is few bytes (more than one due to
+	  escape sequences). However, if bulk data is transferred it may be
+	  required to increase it.
+
+choice
+	prompt "Initial log level limit"
+	default SHELL_NFC_INIT_LOG_LEVEL_NONE
+
+config SHELL_NFC_INIT_LOG_LEVEL_DEFAULT
+	bool "System limit (LOG_MAX_LEVEL)"
+
+config SHELL_NFC_INIT_LOG_LEVEL_DBG
+	bool "Debug"
+
+config SHELL_NFC_INIT_LOG_LEVEL_INF
+	bool "Info"
+
+config SHELL_NFC_INIT_LOG_LEVEL_WRN
+	bool "Warning"
+
+config SHELL_NFC_INIT_LOG_LEVEL_ERR
+	bool "Error"
+
+config SHELL_NFC_INIT_LOG_LEVEL_NONE
+	bool "None"
+
+endchoice
+
+config SHELL_NFC_INIT_LOG_LEVEL
+	int
+	default 0 if SHELL_NFC_INIT_LOG_LEVEL_NONE
+	default 1 if SHELL_NFC_INIT_LOG_LEVEL_ERR
+	default 2 if SHELL_NFC_INIT_LOG_LEVEL_WRN
+	default 3 if SHELL_NFC_INIT_LOG_LEVEL_INF
+	default 4 if SHELL_NFC_INIT_LOG_LEVEL_DBG
+	default 5 if SHELL_NFC_INIT_LOG_LEVEL_DEFAULT
+
+module = SHELL_NFC
+module-str = Shell over the NFC T4T ISO-DEP
+source "${ZEPHYR_BASE}/subsys/logging/Kconfig.template.log_config"
+
+default-timeout = 100
+source "${ZEPHYR_BASE}/subsys/shell/Kconfig.template.shell_log_queue_timeout"
+
+default-size = 10
+source "${ZEPHYR_BASE}/subsys/shell/Kconfig.template.shell_log_queue_size"
+
+
+endif # SHELL_NFC