Add debug command

module/mfrc522_module.c

@@ -8,6 +8,7 @@
 #include <linux/regmap.h>
 #include <linux/fs.h>
 
+#include "mfrc522_module.h"
 #include "mfrc522_user_command.h"
 #include "mfrc522_parser.h"
 #include "mfrc522_spi.h"
@@ -19,18 +20,62 @@
 
 #define MFRC522_MAX_ANSWER_SIZE 256 // FIXME
 
-struct mfrc522_state {
-	struct miscdevice misc;
-	bool buffer_full;
-	char answer[MFRC522_MAX_ANSWER_SIZE];
-};
-
 static struct mfrc522_state *g_state;
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("ks0n");
 MODULE_DESCRIPTION("Driver for the MFRC522 RFID Chip");
 
+static void do_debug_read(const char *answer, int answer_size)
+{
+
+	pr_info("RD\n");
+
+	for (int i = 0; i < answer_size; i++)  {
+		pr_info("%02x", answer[i]);
+
+		if (i % 5 == 0)
+			pr_info("\n");
+		else
+			pr_info(" ");
+
+	}
+
+	if (answer_size % 5 != 0)
+		pr_info("\n");
+}
+
+static void do_debug_write(const char *cmd)
+{
+	int i;
+
+	for (i = 0; cmd[i]; i++) {
+		pr_info("%02x", answer[i]);
+
+		if (i % 5 == 0)
+			pr_info("\n");
+		else
+			pr_info(" ");
+
+	}
+
+	if (i % 5 != 0)
+		pr_info("\n");
+}
+
+static void do_debug(const struct mfrc522_command *cmd, const char *answer,
+		     int answer_size)
+{
+	switch(cmd->cmd) {
+		case MFRC522_CMD_MEM_READ:
+			do_debug_read(answer, answer_size);
+		case MFRC522_CMD_MEM_WRITE:
+			do_debug_write(cmd->data);
+		default:
+	}
+
+}
+
 static ssize_t __mfrc522_write(struct mfrc522_state *state, const char *buffer,
 			       size_t len)
 {
@@ -48,14 +93,17 @@ static ssize_t __mfrc522_write(struct mfrc522_state *state, const char *buffer,
 	if (command.data[0])
 		pr_info("[MFRC522] With extra data: `%s`\n", command.data);
 
-	answer_size = mfrc522_execute(state->answer, &command);
+	answer_size = mfrc522_execute(state, state->answer, &command);
 
 	if (answer_size < 0) {
 		// Error
 		pr_err("[MFRC522] Error when executing command\n");
 		return -EBADE;
 	}
 
+	if (state->debug_on)
+		do_debug(&command, answer, answer_size);
+
 	// Non-empty answer
 	pr_info("[MFRC522] Answer: \"%.*s\"\n", answer_size, state->answer);
 	state->buffer_full = true;
@@ -196,6 +244,7 @@ static int __init mfrc522_init(void)
 		.minor = MISC_DYNAMIC_MINOR,
 		.name = "mfrc522_misc",
 		.fops = &mfrc522_fops,
+		.debug_on = false,
 	};
 
 	ret = misc_register(&state->misc);

module/mfrc522_module.h

@@ -0,0 +1,11 @@
+#ifndef MFRC522_MODULE_H
+#define MFRC522_MODULE_H
+
+struct mfrc522_state {
+	struct miscdevice misc;
+	bool buffer_full;
+	char answer[MFRC522_MAX_ANSWER_SIZE];
+	bool debug_on;
+};
+
+#endif /* ! MFRC522_MODULE_H */

module/mfrc522_parser.c

@@ -32,6 +32,9 @@ static const struct driver_command commands[MFRC522_CMD_AMOUNT] = {
 	{ .input = "version",
 	  .parameter_amount = 0,
 	  .cmd = MFRC522_CMD_GET_VERSION },
+	{ .input = "debug",
+	  .parameter_amount = 1,
+	  .cmd = MFRC522_CMD_DEBUG },
 };
 
 /**

module/mfrc522_user_command.c

@@ -127,7 +127,18 @@ static int generate_random(char *answer)
 	return 0;
 }
 
-int mfrc522_execute(char *answer, struct mfrc522_command *cmd)
+static int set_debug(struct mfrc522_state *state, const struct mfrc522_command *cmd) {
+	if (!strncmp(cmd->data, "on", 3))
+		state->debug_on = true;
+	else if (!strncmp(cmd->data, "off", 4))
+		state->debug_on = false;
+	else
+		return -1;
+
+	return 0;
+}
+
+int mfrc522_execute(struct mfrc522_state *state, char *answer, struct mfrc522_command *cmd)
 {
 	int ret = -1;
 
@@ -144,6 +155,9 @@ int mfrc522_execute(char *answer, struct mfrc522_command *cmd)
 	case MFRC522_CMD_GEN_RANDOM:
 		ret = generate_random(answer);
 		break;
+	case MFRC522_CMD_DEBUG:
+		ret = set_debug(state, cmd->data);
+		break;
 	default:
 		ret = sprintf(answer, "%s", "Command unimplemented");
 	}

module/mfrc522_user_command.h

@@ -14,6 +14,7 @@ enum mfrc522_commands {
 	MFRC522_CMD_MEM_READ,
 	MFRC522_CMD_GET_VERSION,
 	MFRC522_CMD_GEN_RANDOM,
+    MFRC522_CMD_DEBUG,
 };
 
 struct mfrc522_command {
@@ -52,6 +53,6 @@ int mfrc522_command_simple_init(struct mfrc522_command *cmd, u8 cmd_byte);
  *
  * @return The size of the answer on success, -1 on error
  */
-int mfrc522_execute(char *answer, struct mfrc522_command *cmd);
+int mfrc522_execute(struct mfrc522_state *state, char *answer, struct mfrc522_command *cmd);
 
 #endif /* ! MFRC522_COMMAND_H */