From e05aa6dc3e517d0e0045279fb4f2af02b8f76821 Mon Sep 17 00:00:00 2001
From: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Date: Wed, 9 Jun 2021 10:53:53 +0200
Subject: [PATCH] shell: Add option to bypass shell

Added api call that can set a callback that is called whenever
data is received on shell. When callback is set, shell processing
is bypassed and data is passed to that callback.

Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
---
 include/shell/shell.h | 23 +++++++++++++++++++++++
 subsys/shell/shell.c  | 31 ++++++++++++++++++++++++++++---
 2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/include/shell/shell.h b/include/shell/shell.h
index 00221ad4bfa..ee3e7a8f722 100644
--- a/include/shell/shell.h
+++ b/include/shell/shell.h
@@ -501,6 +501,16 @@ typedef void (*shell_transport_handler_t)(enum shell_transport_evt evt,
 
 typedef void (*shell_uninit_cb_t)(const struct shell *shell, int res);
 
+/** @brief Bypass callback.
+ *
+ * @param shell Shell instance.
+ * @param data  Raw data from transport.
+ * @param len   Data length.
+ */
+typedef void (*shell_bypass_cb_t)(const struct shell *shell,
+				  uint8_t *data,
+				  size_t len);
+
 struct shell_transport;
 
 /**
@@ -663,6 +673,9 @@ struct shell_ctx {
 	 */
 	shell_uninit_cb_t uninit_cb;
 
+	/*!< When bypass is set, all incoming data is passed to the callback. */
+	shell_bypass_cb_t bypass;
+
 #if defined CONFIG_SHELL_GETOPT
 	/*!< getopt context for a shell backend. */
 	struct getopt_state getopt_state;
@@ -1044,6 +1057,16 @@ int shell_execute_cmd(const struct shell *shell, const char *cmd);
  */
 int shell_set_root_cmd(const char *cmd);
 
+/** @brief Set bypass callback.
+ *
+ * Bypass callback is called whenever data is received. Shell is bypassed and
+ * data is passed directly to the callback. Use null to disable bypass functionality.
+ *
+ * @param[in] shell	Pointer to the shell instance.
+ * @param[in] bypass	Bypass callback or null to disable.
+ */
+void shell_set_bypass(const struct shell *shell, shell_bypass_cb_t bypass);
+
 /**
  * @brief Allow application to control text insert mode.
  * Value is modified atomically and the previous value is returned.
diff --git a/subsys/shell/shell.c b/subsys/shell/shell.c
index c71f54e6844..5ddf137ca12 100644
--- a/subsys/shell/shell.c
+++ b/subsys/shell/shell.c
@@ -88,7 +88,7 @@ static inline void state_set(const struct shell *shell, enum shell_state state)
 {
 	shell->ctx->state = state;
 
-	if (state == SHELL_STATE_ACTIVE) {
+	if (state == SHELL_STATE_ACTIVE && !shell->ctx->bypass) {
 		cmd_buffer_clear(shell);
 		if (z_flag_print_noinit_get(shell)) {
 			z_shell_fprintf(shell, SHELL_WARNING, "%s",
@@ -940,6 +940,26 @@ static void state_collect(const struct shell *shell)
 	char data;
 
 	while (true) {
+		shell_bypass_cb_t bypass = shell->ctx->bypass;
+
+		if (bypass) {
+			uint8_t buf[16];
+
+			(void)shell->iface->api->read(shell->iface, buf,
+							sizeof(buf), &count);
+			if (count) {
+				bypass(shell, buf, count);
+				/* Check if bypass mode ended. */
+				if (!(volatile shell_bypass_cb_t *)shell->ctx->bypass) {
+					state_set(shell, SHELL_STATE_ACTIVE);
+				} else {
+					continue;
+				}
+			}
+
+			return;
+		}
+
 		(void)shell->iface->api->read(shell->iface, &data,
 					      sizeof(data), &count);
 		if (count == 0) {
@@ -1447,11 +1467,11 @@ void shell_vfprintf(const struct shell *shell, enum shell_vt100_color color,
 	}
 
 	k_mutex_lock(&shell->ctx->wr_mtx, K_FOREVER);
-	if (!z_flag_cmd_ctx_get(shell)) {
+	if (!z_flag_cmd_ctx_get(shell) && !shell->ctx->bypass) {
 		z_shell_cmd_line_erase(shell);
 	}
 	z_shell_vfprintf(shell, color, fmt, args);
-	if (!z_flag_cmd_ctx_get(shell)) {
+	if (!z_flag_cmd_ctx_get(shell) && !shell->ctx->bypass) {
 		z_shell_print_prompt_and_cmd(shell);
 	}
 	z_transport_buffer_flush(shell);
@@ -1627,6 +1647,11 @@ int shell_mode_delete_set(const struct shell *shell, bool val)
 	return (int)z_flag_mode_delete_set(shell, val);
 }
 
+void shell_set_bypass(const struct shell *sh, shell_bypass_cb_t bypass)
+{
+	sh->ctx->bypass = bypass;
+}
+
 static int cmd_help(const struct shell *shell, size_t argc, char **argv)
 {
 	ARG_UNUSED(argc);