1 files changed, 154 insertions, 0 deletions

diff --git a/drivers/media/IR/ir-rc5-sz-decoder.c b/drivers/media/IR/ir-rc5-sz-decoder.c
new file mode 100644
index 000000000000..7c413501a3f7
--- /dev/null
+++ b/drivers/media/IR/ir-rc5-sz-decoder.c
@@ -0,0 +1,154 @@
+/* ir-rc5-sz-decoder.c - handle RC5 Streamzap IR Pulse/Space protocol
+ *
+ * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
+ * Copyright (C) 2010 by Jarod Wilson <jarod@redhat.com>
+ *
+ * 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.
+ */
+
+/*
+ * This code handles the 15 bit RC5-ish protocol used by the Streamzap
+ * PC Remote.
+ * It considers a carrier of 36 kHz, with a total of 15 bits, where
+ * the first two bits are start bits, and a third one is a filing bit
+ */
+
+#include "ir-core-priv.h"
+
+#define RC5_SZ_NBITS            15
+#define RC5_UNIT                888888 /* ns */
+#define RC5_BIT_START           (1 * RC5_UNIT)
+#define RC5_BIT_END             (1 * RC5_UNIT)
+
+enum rc5_sz_state {
+        STATE_INACTIVE,
+        STATE_BIT_START,
+        STATE_BIT_END,
+        STATE_FINISHED,
+};
+
+/**
+ * ir_rc5_sz_decode() - Decode one RC-5 Streamzap pulse or space
+ * @input_dev:  the struct input_dev descriptor of the device
+ * @ev:         the struct ir_raw_event descriptor of the pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
+ */
+static int ir_rc5_sz_decode(struct input_dev *input_dev, struct ir_raw_event ev)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        struct rc5_sz_dec *data = &ir_dev->raw->rc5_sz;
+        u8 toggle, command, system;
+        u32 scancode;
+
+        if (!(ir_dev->raw->enabled_protocols & IR_TYPE_RC5_SZ))
+                return 0;
+
+        if (!is_timing_event(ev)) {
+                if (ev.reset)
+                        data->state = STATE_INACTIVE;
+                return 0;
+        }
+
+        if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
+                goto out;
+
+again:
+        IR_dprintk(2, "RC5-sz decode started at state %i (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+
+        if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
+                return 0;
+
+        switch (data->state) {
+
+        case STATE_INACTIVE:
+                if (!ev.pulse)
+                        break;
+
+                data->state = STATE_BIT_START;
+                data->count = 1;
+                data->wanted_bits = RC5_SZ_NBITS;
+                decrease_duration(&ev, RC5_BIT_START);
+                goto again;
+
+        case STATE_BIT_START:
+                if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2))
+                        break;
+
+                data->bits <<= 1;
+                if (!ev.pulse)
+                        data->bits |= 1;
+                data->count++;
+                data->state = STATE_BIT_END;
+                return 0;
+
+        case STATE_BIT_END:
+                if (!is_transition(&ev, &ir_dev->raw->prev_ev))
+                        break;
+
+                if (data->count == data->wanted_bits)
+                        data->state = STATE_FINISHED;
+                else
+                        data->state = STATE_BIT_START;
+
+                decrease_duration(&ev, RC5_BIT_END);
+                goto again;
+
+        case STATE_FINISHED:
+                if (ev.pulse)
+                        break;
+
+                /* RC5-sz */
+                command  = (data->bits & 0x0003F) >> 0;
+                system   = (data->bits & 0x02FC0) >> 6;
+                toggle   = (data->bits & 0x01000) ? 1 : 0;
+                scancode = system << 6 | command;
+
+                IR_dprintk(1, "RC5-sz scancode 0x%04x (toggle: %u)\n",
+                           scancode, toggle);
+
+                ir_keydown(input_dev, scancode, toggle);
+                data->state = STATE_INACTIVE;
+                return 0;
+        }
+
+out:
+        IR_dprintk(1, "RC5-sz decode failed at state %i (%uus %s)\n",
+                   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
+        data->state = STATE_INACTIVE;
+        return -EINVAL;
+}
+
+static struct ir_raw_handler rc5_sz_handler = {
+        .protocols      = IR_TYPE_RC5_SZ,
+        .decode         = ir_rc5_sz_decode,
+};
+
+static int __init ir_rc5_sz_decode_init(void)
+{
+        ir_raw_handler_register(&rc5_sz_handler);
+
+        printk(KERN_INFO "IR RC5 (streamzap) protocol handler initialized\n");
+        return 0;
+}
+
+static void __exit ir_rc5_sz_decode_exit(void)
+{
+        ir_raw_handler_unregister(&rc5_sz_handler);
+}
+
+module_init(ir_rc5_sz_decode_init);
+module_exit(ir_rc5_sz_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
+MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
+MODULE_DESCRIPTION("RC5 (streamzap) IR protocol decoder");