--- /dev/null
+/* ir-xmp-decoder.c - handle XMP IR Pulse/Space protocol
+ *
+ * Copyright (C) 2014 by Marcel Mol
+ *
+ * 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.
+ *
+ * - Based on info from http://www.hifi-remote.com
+ * - Ignore Toggle=9 frames
+ * - Ignore XMP-1 XMP-2 difference, always store 16 bit OBC
+ */
+
+#include <linux/bitrev.h>
+#include <linux/module.h>
+#include "rc-core-priv.h"
+
+#define XMP_UNIT 136000 /* ns */
+#define XMP_LEADER 210000 /* ns */
+#define XMP_NIBBLE_PREFIX 760000 /* ns */
+#define XMP_HALFFRAME_SPACE 13800000 /* ns */
+#define XMP_TRAILER_SPACE 20000000 /* should be 80ms but not all dureation supliers can go that high */
+
+enum xmp_state {
+ STATE_INACTIVE,
+ STATE_LEADER_PULSE,
+ STATE_NIBBLE_SPACE,
+};
+
+/**
+ * ir_xmp_decode() - Decode one XMP 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_xmp_decode(struct rc_dev *dev, struct ir_raw_event ev)
+{
+ struct xmp_dec *data = &dev->raw->xmp;
+
+ if (!(dev->enabled_protocols & RC_BIT_XMP))
+ return 0;
+
+ if (!is_timing_event(ev)) {
+ if (ev.reset)
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
+
+ IR_dprintk(2, "XMP decode started at state %d %d (%uus %s)\n",
+ data->state, data->count, TO_US(ev.duration), TO_STR(ev.pulse));
+
+ switch (data->state) {
+
+ case STATE_INACTIVE:
+ if (!ev.pulse)
+ break;
+
+ if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2)) {
+ data->count = 0;
+ data->state = STATE_NIBBLE_SPACE;
+ }
+
+ return 0;
+
+ case STATE_LEADER_PULSE:
+ if (!ev.pulse)
+ break;
+
+ if (eq_margin(ev.duration, XMP_LEADER, XMP_UNIT / 2))
+ data->state = STATE_NIBBLE_SPACE;
+
+ return 0;
+
+ case STATE_NIBBLE_SPACE:
+ if (ev.pulse)
+ break;
+
+ if (geq_margin(ev.duration, XMP_TRAILER_SPACE, XMP_NIBBLE_PREFIX)) {
+ int divider, i;
+ u8 addr, subaddr, subaddr2, toggle, oem, obc1, obc2, sum1, sum2;
+ u32 *n;
+ u32 scancode;
+
+ if (data->count != 16) {
+ IR_dprintk(2, "received TRAILER period at index %d: %u\n",
+ data->count, ev.duration);
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+ }
+
+ n = data->durations;
+ /*
+ * the 4th nibble should be 15 so base the divider on this
+ * to transform durations into nibbles. Substract 2000 from
+ * the divider to compensate for fluctuations in the signal
+ */
+ divider = (n[3] - XMP_NIBBLE_PREFIX) / 15 - 2000;
+ if (divider < 50) {
+ IR_dprintk(2, "divider to small %d.\n", divider);
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+ }
+
+ /* convert to nibbles and do some sanity checks */
+ for (i = 0; i < 16; i++)
+ n[i] = (n[i] - XMP_NIBBLE_PREFIX) / divider;
+ sum1 = (15 + n[0] + n[1] + n[2] + n[3] +
+ n[4] + n[5] + n[6] + n[7]) % 16;
+ sum2 = (15 + n[8] + n[9] + n[10] + n[11] +
+ n[12] + n[13] + n[14] + n[15]) % 16;
+
+ if (sum1 != 15 || sum2 != 15) {
+ IR_dprintk(2, "checksum errors sum1=0x%X sum2=0x%X\n",
+ sum1, sum2);
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+ }
+
+ subaddr = n[0] << 4 | n[2];
+ subaddr2 = n[8] << 4 | n[11];
+ oem = n[4] << 4 | n[5];
+ addr = n[6] << 4 | n[7];
+ toggle = n[10];
+ obc1 = n[12] << 4 | n[13];
+ obc2 = n[14] << 4 | n[15];
+ if (subaddr != subaddr2) {
+ IR_dprintk(2, "subaddress nibbles mismatch 0x%02X != 0x%02X\n",
+ subaddr, subaddr2);
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+ }
+ if (oem != 0x44)
+ IR_dprintk(1, "Warning: OEM nibbles 0x%02X. Expected 0x44\n",
+ oem);
+
+ scancode = addr << 24 | subaddr << 16 |
+ obc1 << 8 | obc2;
+ IR_dprintk(1, "XMP scancode 0x%06x\n", scancode);
+
+ if (toggle == 0) {
+ rc_keydown(dev, RC_TYPE_XMP, scancode, 0);
+ } else {
+ rc_repeat(dev);
+ IR_dprintk(1, "Repeat last key\n");
+ }
+ data->state = STATE_INACTIVE;
+
+ return 0;
+
+ } else if (geq_margin(ev.duration, XMP_HALFFRAME_SPACE, XMP_NIBBLE_PREFIX)) {
+ /* Expect 8 or 16 nibble pulses. 16 in case of 'final' frame */
+ if (data->count == 16) {
+ IR_dprintk(2, "received half frame pulse at index %d. Probably a final frame key-up event: %u\n",
+ data->count, ev.duration);
+ /*
+ * TODO: for now go back to half frame position
+ * so trailer can be found and key press
+ * can be handled.
+ */
+ data->count = 8;
+ }
+
+ else if (data->count != 8)
+ IR_dprintk(2, "received half frame pulse at index %d: %u\n",
+ data->count, ev.duration);
+ data->state = STATE_LEADER_PULSE;
+
+ return 0;
+
+ } else if (geq_margin(ev.duration, XMP_NIBBLE_PREFIX, XMP_UNIT)) {
+ /* store nibble raw data, decode after trailer */
+ if (data->count == 16) {
+ IR_dprintk(2, "to many pulses (%d) ignoring: %u\n",
+ data->count, ev.duration);
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+ }
+ data->durations[data->count] = ev.duration;
+ data->count++;
+ data->state = STATE_LEADER_PULSE;
+
+ return 0;
+
+ }
+
+ break;
+ }
+
+ IR_dprintk(1, "XMP decode failed at count %d state %d (%uus %s)\n",
+ data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+}
+
+static struct ir_raw_handler xmp_handler = {
+ .protocols = RC_BIT_XMP,
+ .decode = ir_xmp_decode,
+};
+
+static int __init ir_xmp_decode_init(void)
+{
+ ir_raw_handler_register(&xmp_handler);
+
+ printk(KERN_INFO "IR XMP protocol handler initialized\n");
+ return 0;
+}
+
+static void __exit ir_xmp_decode_exit(void)
+{
+ ir_raw_handler_unregister(&xmp_handler);
+}
+
+module_init(ir_xmp_decode_init);
+module_exit(ir_xmp_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marcel Mol <marcel@mesa.nl>");
+MODULE_AUTHOR("MESA Consulting (http://www.mesa.nl)");
+MODULE_DESCRIPTION("XMP IR protocol decoder");
projects / deliverable / linux.git / commitdiff
