1 files changed, 225 insertions, 0 deletions

diff --git a/drivers/media/rc/ir-xmp-decoder.c b/drivers/media/rc/ir-xmp-decoder.c
new file mode 100644
index 000000000000..1017d4816e8d
--- /dev/null
+++ b/drivers/media/rc/ir-xmp-decoder.c
@@ -0,0 +1,225 @@
+/* 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");