+/* ir-jvc-decoder.c - handle JVC IR Pulse/Space protocol
+ *
+ * Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitrev.h>
+#include "ir-core-priv.h"
+
+#define JVC_NBITS 16 /* dev(8) + func(8) */
+#define JVC_UNIT 525000 /* ns */
+#define JVC_HEADER_PULSE (16 * JVC_UNIT) /* lack of header -> repeat */
+#define JVC_HEADER_SPACE (8 * JVC_UNIT)
+#define JVC_BIT_PULSE (1 * JVC_UNIT)
+#define JVC_BIT_0_SPACE (1 * JVC_UNIT)
+#define JVC_BIT_1_SPACE (3 * JVC_UNIT)
+#define JVC_TRAILER_PULSE (1 * JVC_UNIT)
+#define JVC_TRAILER_SPACE (35 * JVC_UNIT)
+
+/* Used to register jvc_decoder clients */
+static LIST_HEAD(decoder_list);
+DEFINE_SPINLOCK(decoder_lock);
+
+enum jvc_state {
+ STATE_INACTIVE,
+ STATE_HEADER_SPACE,
+ STATE_BIT_PULSE,
+ STATE_BIT_SPACE,
+ STATE_TRAILER_PULSE,
+ STATE_TRAILER_SPACE,
+};
+
+struct decoder_data {
+ struct list_head list;
+ struct ir_input_dev *ir_dev;
+ int enabled:1;
+
+ /* State machine control */
+ enum jvc_state state;
+ u16 jvc_bits;
+ u16 jvc_old_bits;
+ unsigned count;
+ bool first;
+ bool toggle;
+};
+
+
+/**
+ * get_decoder_data() - gets decoder data
+ * @input_dev: input device
+ *
+ * Returns the struct decoder_data that corresponds to a device
+ */
+static struct decoder_data *get_decoder_data(struct ir_input_dev *ir_dev)
+{
+ struct decoder_data *data = NULL;
+
+ spin_lock(&decoder_lock);
+ list_for_each_entry(data, &decoder_list, list) {
+ if (data->ir_dev == ir_dev)
+ break;
+ }
+ spin_unlock(&decoder_lock);
+ return data;
+}
+
+static ssize_t store_enabled(struct device *d,
+ struct device_attribute *mattr,
+ const char *buf,
+ size_t len)
+{
+ unsigned long value;
+ struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+ struct decoder_data *data = get_decoder_data(ir_dev);
+
+ if (!data)
+ return -EINVAL;
+
+ if (strict_strtoul(buf, 10, &value) || value > 1)
+ return -EINVAL;
+
+ data->enabled = value;
+
+ return len;
+}
+
+static ssize_t show_enabled(struct device *d,
+ struct device_attribute *mattr, char *buf)
+{
+ struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+ struct decoder_data *data = get_decoder_data(ir_dev);
+
+ if (!data)
+ return -EINVAL;
+
+ if (data->enabled)
+ return sprintf(buf, "1\n");
+ else
+ return sprintf(buf, "0\n");
+}
+
+static DEVICE_ATTR(enabled, S_IRUGO | S_IWUSR, show_enabled, store_enabled);
+
+static struct attribute *decoder_attributes[] = {
+ &dev_attr_enabled.attr,
+ NULL
+};
+
+static struct attribute_group decoder_attribute_group = {
+ .name = "jvc_decoder",
+ .attrs = decoder_attributes,
+};
+
+/**
+ * ir_jvc_decode() - Decode one JVC pulse or space
+ * @input_dev: the struct input_dev descriptor of the device
+ * @duration: the struct ir_raw_event descriptor of the pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
+ */
+static int ir_jvc_decode(struct input_dev *input_dev, struct ir_raw_event ev)
+{
+ struct decoder_data *data;
+ struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+
+ data = get_decoder_data(ir_dev);
+ if (!data)
+ return -EINVAL;
+
+ if (!data->enabled)
+ return 0;
+
+ if (IS_RESET(ev)) {
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
+
+ if (!geq_margin(ev.duration, JVC_UNIT, JVC_UNIT / 2))
+ goto out;
+
+ IR_dprintk(2, "JVC decode started at state %d (%uus %s)\n",
+ data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+
+ switch (data->state) {
+
+ case STATE_INACTIVE:
+ if (!ev.pulse)
+ break;
+
+ if (!eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
+ break;
+
+ data->count = 0;
+ data->first = true;
+ data->toggle = !data->toggle;
+ data->state = STATE_HEADER_SPACE;
+ return 0;
+
+ case STATE_HEADER_SPACE:
+ if (ev.pulse)
+ break;
+
+ if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2))
+ break;
+
+ data->state = STATE_BIT_PULSE;
+ return 0;
+
+ case STATE_BIT_PULSE:
+ if (!ev.pulse)
+ break;
+
+ if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2))
+ break;
+
+ data->state = STATE_BIT_SPACE;
+ return 0;
+
+ case STATE_BIT_SPACE:
+ if (ev.pulse)
+ break;
+
+ data->jvc_bits <<= 1;
+ if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) {
+ data->jvc_bits |= 1;
+ decrease_duration(&ev, JVC_BIT_1_SPACE);
+ } else if (eq_margin(ev.duration, JVC_BIT_0_SPACE, JVC_UNIT / 2))
+ decrease_duration(&ev, JVC_BIT_0_SPACE);
+ else
+ break;
+ data->count++;
+
+ if (data->count == JVC_NBITS)
+ data->state = STATE_TRAILER_PULSE;
+ else
+ data->state = STATE_BIT_PULSE;
+ return 0;
+
+ case STATE_TRAILER_PULSE:
+ if (!ev.pulse)
+ break;
+
+ if (!eq_margin(ev.duration, JVC_TRAILER_PULSE, JVC_UNIT / 2))
+ break;
+
+ data->state = STATE_TRAILER_SPACE;
+ return 0;
+
+ case STATE_TRAILER_SPACE:
+ if (ev.pulse)
+ break;
+
+ if (!geq_margin(ev.duration, JVC_TRAILER_SPACE, JVC_UNIT / 2))
+ break;
+
+ if (data->first) {
+ u32 scancode;
+ scancode = (bitrev8((data->jvc_bits >> 8) & 0xff) << 8) |
+ (bitrev8((data->jvc_bits >> 0) & 0xff) << 0);
+ IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
+ ir_keydown(input_dev, scancode, data->toggle);
+ data->first = false;
+ data->jvc_old_bits = data->jvc_bits;
+ } else if (data->jvc_bits == data->jvc_old_bits) {
+ IR_dprintk(1, "JVC repeat\n");
+ ir_repeat(input_dev);
+ } else {
+ IR_dprintk(1, "JVC invalid repeat msg\n");
+ break;
+ }
+
+ data->count = 0;
+ data->state = STATE_BIT_PULSE;
+ return 0;
+ }
+
+out:
+ IR_dprintk(1, "JVC decode failed at state %d (%uus %s)\n",
+ data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+}
+
+static int ir_jvc_register(struct input_dev *input_dev)
+{
+ struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+ struct decoder_data *data;
+ int rc;
+
+ rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+ if (rc < 0)
+ return rc;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data) {
+ sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+ return -ENOMEM;
+ }
+
+ data->ir_dev = ir_dev;
+ data->enabled = 1;
+
+ spin_lock(&decoder_lock);
+ list_add_tail(&data->list, &decoder_list);
+ spin_unlock(&decoder_lock);
+
+ return 0;
+}
+
+static int ir_jvc_unregister(struct input_dev *input_dev)
+{
+ struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+ static struct decoder_data *data;
+
+ data = get_decoder_data(ir_dev);
+ if (!data)
+ return 0;
+
+ sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+
+ spin_lock(&decoder_lock);
+ list_del(&data->list);
+ spin_unlock(&decoder_lock);
+
+ return 0;
+}
+
+static struct ir_raw_handler jvc_handler = {
+ .decode = ir_jvc_decode,
+ .raw_register = ir_jvc_register,
+ .raw_unregister = ir_jvc_unregister,
+};
+
+static int __init ir_jvc_decode_init(void)
+{
+ ir_raw_handler_register(&jvc_handler);
+
+ printk(KERN_INFO "IR JVC protocol handler initialized\n");
+ return 0;
+}
+
+static void __exit ir_jvc_decode_exit(void)
+{
+ ir_raw_handler_unregister(&jvc_handler);
+}
+
+module_init(ir_jvc_decode_init);
+module_exit(ir_jvc_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
+MODULE_DESCRIPTION("JVC IR protocol decoder");
projects / karo-tx-linux.git / commitdiff