--- /dev/null
+/* 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 <linux/module.h>
+#include "rc-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)
+
+enum jvc_state {
+ STATE_INACTIVE,
+ STATE_HEADER_SPACE,
+ STATE_BIT_PULSE,
+ STATE_BIT_SPACE,
+ STATE_TRAILER_PULSE,
+ STATE_TRAILER_SPACE,
+ STATE_CHECK_REPEAT,
+};
+
+/**
+ * ir_jvc_decode() - Decode one JVC pulse or space
+ * @dev: the struct rc_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 rc_dev *dev, struct ir_raw_event ev)
+{
+ struct jvc_dec *data = &dev->raw->jvc;
+
+ if (!(dev->enabled_protocols & RC_BIT_JVC))
+ return 0;
+
+ if (!is_timing_event(ev)) {
+ if (ev.reset)
+ 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));
+
+again:
+ 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->bits <<= 1;
+ if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) {
+ data->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->bits >> 8) & 0xff) << 8) |
+ (bitrev8((data->bits >> 0) & 0xff) << 0);
+ IR_dprintk(1, "JVC scancode 0x%04x\n", scancode);
+ rc_keydown(dev, RC_TYPE_JVC, scancode, data->toggle);
+ data->first = false;
+ data->old_bits = data->bits;
+ } else if (data->bits == data->old_bits) {
+ IR_dprintk(1, "JVC repeat\n");
+ rc_repeat(dev);
+ } else {
+ IR_dprintk(1, "JVC invalid repeat msg\n");
+ break;
+ }
+
+ data->count = 0;
+ data->state = STATE_CHECK_REPEAT;
+ return 0;
+
+ case STATE_CHECK_REPEAT:
+ if (!ev.pulse)
+ break;
+
+ if (eq_margin(ev.duration, JVC_HEADER_PULSE, JVC_UNIT / 2))
+ data->state = STATE_INACTIVE;
+ else
+ data->state = STATE_BIT_PULSE;
+ goto again;
+ }
+
+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 struct ir_raw_handler jvc_handler = {
+ .protocols = RC_BIT_JVC,
+ .decode = ir_jvc_decode,
+};
+
+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");
Code Review / kvmfornfv.git / blobdiff