V4L/DVB: Add RC5x support to ir-core

This patch adds RC5x support to drivers/media/IR/ir-rc5-decoder.c

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 59 insertions, 19 deletions

diff --git a/drivers/media/IR/ir-rc5-decoder.c b/drivers/media/IR/ir-rc5-decoder.c
index d8f0760890f..dd5a4d5f25f 100644
--- a/drivers/media/IR/ir-rc5-decoder.c
+++ b/drivers/media/IR/ir-rc5-decoder.c
@@ -1,4 +1,4 @@
-/* ir-rc5-decoder.c - handle RC-5 IR Pulse/Space protocol
+/* ir-rc5-decoder.c - handle RC5(x) IR Pulse/Space protocol
  *
  * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
  *
@@ -13,15 +13,19 @@
  */
 
 /*
- * This code only handles 14 bits RC-5 protocols. There are other variants
- * that use a different number of bits. This is currently unsupported
- * It considers a carrier of 36 kHz, with a total of 14 bits, where
+ * This code handles 14 bits RC5 protocols and 20 bits RC5x protocols.
+ * There are other variants that use a different number of bits.
+ * This is currently unsupported.
+ * It considers a carrier of 36 kHz, with a total of 14/20 bits, where
  * the first two bits are start bits, and a third one is a filing bit
  */
 
 #include "ir-core-priv.h"
 
 #define RC5_NBITS               14
+#define RC5X_NBITS              20
+#define CHECK_RC5X_NBITS        8
+#define RC5X_SPACE              SPACE(4)
 #define RC5_UNIT                888888 /* ns */
 
 /* Used to register rc5_decoder clients */
@@ -32,6 +36,7 @@ enum rc5_state {
         STATE_INACTIVE,
         STATE_BIT_START,
         STATE_BIT_END,
+        STATE_CHECK_RC5X,
         STATE_FINISHED,
 };
 
@@ -45,6 +50,7 @@ struct decoder_data {
         u32                     rc5_bits;
         int                     last_unit;
         unsigned                count;
+        unsigned                wanted_bits;
 };
 
 
@@ -126,7 +132,7 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
 {
         struct decoder_data *data;
         struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
-        u8 command, system, toggle;
+        u8 toggle;
         u32 scancode;
         int u;
 
@@ -147,7 +153,7 @@ static int ir_rc5_decode(struct input_dev *input_dev, s64 duration)
                 goto out;
 
 again:
-        IR_dprintk(2, "RC5 decode started at state %i (%i units, %ius)\n",
+        IR_dprintk(2, "RC5(x) decode started at state %i (%i units, %ius)\n",
                    data->state, u, TO_US(duration));
 
         if (DURATION(u) == 0 && data->state != STATE_FINISHED)
@@ -159,6 +165,8 @@ again:
                 if (IS_PULSE(u)) {
                         data->state = STATE_BIT_START;
                         data->count = 1;
+                        /* We just need enough bits to get to STATE_CHECK_RC5X */
+                        data->wanted_bits = RC5X_NBITS;
                         DECREASE_DURATION(u, 1);
                         goto again;
                 }
@@ -176,7 +184,7 @@ again:
                          * If the last bit is zero, a space will merge
                          * with the silence after the command.
                          */
-                        if (IS_PULSE(u) && data->count == RC5_NBITS) {
+                        if (IS_PULSE(u) && data->count == data->wanted_bits) {
                                 data->state = STATE_FINISHED;
                                 goto again;
                         }
@@ -188,8 +196,10 @@ again:
 
         case STATE_BIT_END:
                 if (IS_TRANSITION(u, data->last_unit)) {
-                        if (data->count == RC5_NBITS)
+                        if (data->count == data->wanted_bits)
                                 data->state = STATE_FINISHED;
+                        else if (data->count == CHECK_RC5X_NBITS)
+                                data->state = STATE_CHECK_RC5X;
                         else
                                 data->state = STATE_BIT_START;
 
@@ -198,22 +208,52 @@ again:
                 }
                 break;
 
+        case STATE_CHECK_RC5X:
+                if (IS_SPACE(u) && DURATION(u) >= DURATION(RC5X_SPACE)) {
+                        /* RC5X */
+                        data->wanted_bits = RC5X_NBITS;
+                        DECREASE_DURATION(u, DURATION(RC5X_SPACE));
+                } else {
+                        /* RC5 */
+                        data->wanted_bits = RC5_NBITS;
+                }
+                data->state = STATE_BIT_START;
+                goto again;
+
         case STATE_FINISHED:
-                command  = (data->rc5_bits & 0x0003F) >> 0;
-                system   = (data->rc5_bits & 0x007C0) >> 6;
-                toggle   = (data->rc5_bits & 0x00800) ? 1 : 0;
-                command += (data->rc5_bits & 0x01000) ? 0 : 0x40;
-                scancode = system << 8 | command;
-
-                IR_dprintk(1, "RC5 scancode 0x%04x (toggle: %u)\n",
-                           scancode, toggle);
+                if (data->wanted_bits == RC5X_NBITS) {
+                        /* RC5X */
+                        u8 xdata, command, system;
+                        xdata    = (data->rc5_bits & 0x0003F) >> 0;
+                        command  = (data->rc5_bits & 0x00FC0) >> 6;
+                        system   = (data->rc5_bits & 0x1F000) >> 12;
+                        toggle   = (data->rc5_bits & 0x20000) ? 1 : 0;
+                        command += (data->rc5_bits & 0x01000) ? 0 : 0x40;
+                        scancode = system << 16 | command << 8 | xdata;
+
+                        IR_dprintk(1, "RC5X scancode 0x%06x (toggle: %u)\n",
+                                   scancode, toggle);
+
+                } else {
+                        /* RC5 */
+                        u8 command, system;
+                        command  = (data->rc5_bits & 0x0003F) >> 0;
+                        system   = (data->rc5_bits & 0x007C0) >> 6;
+                        toggle   = (data->rc5_bits & 0x00800) ? 1 : 0;
+                        command += (data->rc5_bits & 0x01000) ? 0 : 0x40;
+                        scancode = system << 8 | command;
+
+                        IR_dprintk(1, "RC5 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 decode failed at state %i (%i units, %ius)\n",
+        IR_dprintk(1, "RC5(x) decode failed at state %i (%i units, %ius)\n",
                    data->state, u, TO_US(duration));
         data->state = STATE_INACTIVE;
         return -EINVAL;
@@ -273,7 +313,7 @@ static int __init ir_rc5_decode_init(void)
 {
         ir_raw_handler_register(&rc5_handler);
 
-        printk(KERN_INFO "IR RC-5 protocol handler initialized\n");
+        printk(KERN_INFO "IR RC5(x) protocol handler initialized\n");
         return 0;
 }
 
@@ -288,4 +328,4 @@ module_exit(ir_rc5_decode_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
-MODULE_DESCRIPTION("RC-5 IR protocol decoder");
+MODULE_DESCRIPTION("RC5(x) IR protocol decoder");