+/*
+ * LED Morse Trigger
+ *
+ * Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
+ *
+ * This file was based on: drivers/led/ledtrig-timer.c
+ * Copyright 2005-2006 Openedhand Ltd.
+ * Author: Richard Purdie <rpurdie@openedhand.com>
+ *
+ * also based on the patch '[PATCH] 2.5.59 morse code panics' posted
+ * in the LKML by Tomas Szepe at Thu, 30 Jan 2003
+ * Copyright (C) 2002 Andrew Rodland <arodland@noln.com>
+ * Copyright (C) 2003 Tomas Szepe <szepe@pinerecords.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/leds.h>
+#include <linux/reboot.h>
+#include <linux/ctype.h>
+
+#define MORSE_DELAY_BASE (HZ/2)
+
+#define MORSE_STATE_BLINK_START 0
+#define MORSE_STATE_BLINK_STOP 1
+
+#define MORSE_DIT_LEN 1
+#define MORSE_DAH_LEN 3
+#define MORSE_SPACE_LEN 7
+
+struct morse_trig_data {
+ unsigned long delay;
+ char *msg;
+
+ unsigned char morse;
+ unsigned char state;
+ char *msgpos;
+ struct timer_list timer;
+};
+
+const unsigned char morsetable[] = {
+ 0122, 0, 0310, 0, 0, 0163, /* "#$%&' */
+ 055, 0155, 0, 0, 0163, 0141, 0152, 0051, /* ()*+,-./ */
+ 077, 076, 074, 070, 060, 040, 041, 043, 047, 057, /* 0-9 */
+ 0107, 0125, 0, 0061, 0, 0114, 0, /* :;<=>?@ */
+ 006, 021, 025, 011, 002, 024, 013, 020, 004, /* A-I */
+ 036, 015, 022, 007, 005, 017, 026, 033, 012, /* J-R */
+ 010, 003, 014, 030, 016, 031, 035, 023, /* S-Z */
+ 0, 0, 0, 0, 0154 /* [\]^_ */
+};
+
+static inline unsigned char tomorse(char c) {
+ if (c >= 'a' && c <= 'z')
+ c = c - 'a' + 'A';
+ if (c >= '"' && c <= '_') {
+ return morsetable[c - '"'];
+ } else
+ return 0;
+}
+
+static inline unsigned long dit_len(struct morse_trig_data *morse_data)
+{
+ return MORSE_DIT_LEN*morse_data->delay;
+}
+
+static inline unsigned long dah_len(struct morse_trig_data *morse_data)
+{
+ return MORSE_DAH_LEN*morse_data->delay;
+}
+
+static inline unsigned long space_len(struct morse_trig_data *morse_data)
+{
+ return MORSE_SPACE_LEN*morse_data->delay;
+}
+
+static void morse_timer_function(unsigned long data)
+{
+ struct led_classdev *led_cdev = (struct led_classdev *)data;
+ struct morse_trig_data *morse_data = led_cdev->trigger_data;
+ unsigned long brightness = LED_OFF;
+ unsigned long delay = 0;
+
+ if (!morse_data->msg)
+ goto set_led;
+
+ switch (morse_data->state) {
+ case MORSE_STATE_BLINK_START:
+ /* Starting a new blink. We have a valid code in morse. */
+ delay = (morse_data->morse & 001) ? dah_len(morse_data):
+ dit_len(morse_data);
+ brightness = LED_FULL;
+ morse_data->state = MORSE_STATE_BLINK_STOP;
+ morse_data->morse >>= 1;
+ break;
+ case MORSE_STATE_BLINK_STOP:
+ /* Coming off of a blink. */
+ morse_data->state = MORSE_STATE_BLINK_START;
+
+ if (morse_data->morse > 1) {
+ /* Not done yet, just a one-dit pause. */
+ delay = dit_len(morse_data);
+ break;
+ }
+
+ /* Get a new char, figure out how much space. */
+ /* First time through */
+ if (!morse_data->msgpos)
+ morse_data->msgpos = (char *)morse_data->msg;
+
+ if (!*morse_data->msgpos) {
+ /* Repeating */
+ morse_data->msgpos = (char *)morse_data->msg;
+ delay = space_len(morse_data);
+ } else {
+ /* Inter-letter space */
+ delay = dah_len(morse_data);
+ }
+
+ if (!(morse_data->morse = tomorse(*morse_data->msgpos))) {
+ delay = space_len(morse_data);
+ /* And get us back here */
+ morse_data->state = MORSE_STATE_BLINK_STOP;
+ }
+ morse_data->msgpos++;
+ break;
+ }
+
+ mod_timer(&morse_data->timer, jiffies + msecs_to_jiffies(delay));
+
+set_led:
+ led_set_brightness(led_cdev, brightness);
+}
+
+static ssize_t _morse_delay_show(struct led_classdev *led_cdev, char *buf)
+{
+ struct morse_trig_data *morse_data = led_cdev->trigger_data;
+
+ sprintf(buf, "%lu\n", morse_data->delay);
+
+ return strlen(buf) + 1;
+}
+
+static ssize_t _morse_delay_store(struct led_classdev *led_cdev,
+ const char *buf, size_t size)
+{
+ struct morse_trig_data *morse_data = led_cdev->trigger_data;
+ char *after;
+ unsigned long state = simple_strtoul(buf, &after, 10);
+ size_t count = after - buf;
+ int ret = -EINVAL;
+
+ if (*after && isspace(*after))
+ count++;
+
+ if (count == size) {
+ morse_data->delay = state;
+ mod_timer(&morse_data->timer, jiffies + 1);
+ ret = count;
+ }
+
+ return ret;
+}
+
+static ssize_t _morse_msg_show(struct led_classdev *led_cdev, char *buf)
+{
+ struct morse_trig_data *morse_data = led_cdev->trigger_data;
+
+ if (!morse_data->msg)
+ sprintf(buf, "<none>\n");
+ else
+ sprintf(buf, "%s\n", morse_data->msg);
+
+ return strlen(buf) + 1;
+}
+
+static ssize_t _morse_msg_store(struct led_classdev *led_cdev,
+ const char *buf, size_t size)
+{
+ struct morse_trig_data *morse_data = led_cdev->trigger_data;
+ char *m;
+
+ m = kmalloc(size, GFP_KERNEL);
+ if (!m)
+ return -ENOMEM;
+
+ memcpy(m,buf,size);
+ m[size]='\0';
+
+ if (morse_data->msg)
+ kfree(morse_data->msg);
+
+ morse_data->msg = m;
+ morse_data->msgpos = NULL;
+ morse_data->state = MORSE_STATE_BLINK_STOP;
+
+ mod_timer(&morse_data->timer, jiffies + 1);
+
+ return size;
+}
+
+static ssize_t morse_delay_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+ return _morse_delay_show(led_cdev, buf);
+}
+
+static ssize_t morse_delay_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+ return _morse_delay_store(led_cdev, buf, size);
+}
+
+static ssize_t morse_msg_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+ return _morse_msg_show(led_cdev, buf);
+}
+
+static ssize_t morse_msg_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+ return _morse_msg_store(led_cdev, buf, size);
+}
+
+static DEVICE_ATTR(delay, 0644, morse_delay_show, morse_delay_store);
+static DEVICE_ATTR(message, 0644, morse_msg_show, morse_msg_store);
+
+#define led_device_create_file(leddev, attr) \
+ device_create_file(leddev->dev, &dev_attr_ ## attr)
+#define led_device_remove_file(leddev, attr) \
+ device_remove_file(leddev->dev, &dev_attr_ ## attr)
+
+static void morse_trig_activate(struct led_classdev *led_cdev)
+{
+ struct morse_trig_data *morse_data;
+ int rc;
+
+ morse_data = kzalloc(sizeof(*morse_data), GFP_KERNEL);
+ if (!morse_data)
+ return;
+
+ morse_data->delay = MORSE_DELAY_BASE;
+ init_timer(&morse_data->timer);
+ morse_data->timer.function = morse_timer_function;
+ morse_data->timer.data = (unsigned long)led_cdev;
+
+ rc = led_device_create_file(led_cdev, delay);
+ if (rc) goto err;
+
+ rc = led_device_create_file(led_cdev, message);
+ if (rc) goto err_delay;
+
+ led_cdev->trigger_data = morse_data;
+
+ return;
+
+err_delay:
+ led_device_remove_file(led_cdev, delay);
+err:
+ kfree(morse_data);
+}
+
+static void morse_trig_deactivate(struct led_classdev *led_cdev)
+{
+ struct morse_trig_data *morse_data = led_cdev->trigger_data;
+
+ if (!morse_data)
+ return;
+
+ led_device_remove_file(led_cdev, message);
+ led_device_remove_file(led_cdev, delay);
+
+ del_timer_sync(&morse_data->timer);
+ if (morse_data->msg)
+ kfree(morse_data->msg);
+
+ kfree(morse_data);
+}
+
+static struct led_trigger morse_led_trigger = {
+ .name = "morse",
+ .activate = morse_trig_activate,
+ .deactivate = morse_trig_deactivate,
+};
+
+static int __init morse_trig_init(void)
+{
+ return led_trigger_register(&morse_led_trigger);
+}
+
+static void __exit morse_trig_exit(void)
+{
+ led_trigger_unregister(&morse_led_trigger);
+}
+
+module_init(morse_trig_init);
+module_exit(morse_trig_exit);
+
+MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
+MODULE_DESCRIPTION("Morse LED trigger");
+MODULE_LICENSE("GPL");
+