[media] rc: Add support for decoding XMP protocol

This protocol is found on Dreambox remotes

[m.chehab@samsung.com: CodingStyle fixes and conflict fix]
Signed-off-by: Marcel Mol <marcel@mesa.nl>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

6 files changed, 250 insertions, 0 deletions

diff --git a/drivers/media/rc/Kconfig b/drivers/media/rc/Kconfig
index 9d15a57ac590..5e626af8e313 100644
--- a/drivers/media/rc/Kconfig
+++ b/drivers/media/rc/Kconfig
@@ -113,6 +113,16 @@ config IR_MCE_KBD_DECODER
            Enable this option if you have a Microsoft Remote Keyboard for
            Windows Media Center Edition, which you would like to use with
            a raw IR receiver in your system.
+
+config IR_XMP_DECODER
+        tristate "Enable IR raw decoder for the XMP protocol"
+        depends on RC_CORE
+        select BITREVERSE
+        default y
+
+        ---help---
+           Enable this option if you have IR with XMP protocol, and
+           if the IR is decoded in software
 endif #RC_DECODERS
 
 menuconfig RC_DEVICES
diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
index 096eb0692a04..9f9843a1af5f 100644
--- a/drivers/media/rc/Makefile
+++ b/drivers/media/rc/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_IR_SANYO_DECODER) += ir-sanyo-decoder.o
 obj-$(CONFIG_IR_SHARP_DECODER) += ir-sharp-decoder.o
 obj-$(CONFIG_IR_MCE_KBD_DECODER) += ir-mce_kbd-decoder.o
 obj-$(CONFIG_IR_LIRC_CODEC) += ir-lirc-codec.o
+obj-$(CONFIG_IR_XMP_DECODER) += ir-xmp-decoder.o
 
 # stand-alone IR receivers/transmitters
 obj-$(CONFIG_RC_ATI_REMOTE) += ati_remote.o
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");
diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h
index dea7aff15a35..b68d4f762734 100644
--- a/drivers/media/rc/rc-core-priv.h
+++ b/drivers/media/rc/rc-core-priv.h
@@ -110,6 +110,11 @@ struct ir_raw_event_ctrl {
                 bool send_timeout_reports;
 
         } lirc;
+        struct xmp_dec {
+                int state;
+                unsigned count;
+                u32 durations[16];
+        } xmp;
 };
 
 /* macros for IR decoders */
@@ -225,5 +230,12 @@ static inline void load_mce_kbd_decode(void) { }
 static inline void load_lirc_codec(void) { }
 #endif
 
+/* from ir-xmp-decoder.c */
+#ifdef CONFIG_IR_XMP_DECODER_MODULE
+#define load_xmp_decode()      request_module_nowait("ir-xmp-decoder")
+#else
+static inline void load_xmp_decode(void) { }
+#endif
+
 
 #endif /* _RC_CORE_PRIV */
diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
index e772c4cf9f61..e8fff2add265 100644
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -362,6 +362,7 @@ void ir_raw_init(void)
         load_sharp_decode();
         load_mce_kbd_decode();
         load_lirc_codec();
+        load_xmp_decode();
 
         /* If needed, we may later add some init code. In this case,
            it is needed to change the CONFIG_MODULE test at rc-core.h
diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index 39e4b5ffe141..dfceeb4e34a8 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -800,6 +800,7 @@ static struct {
         { RC_BIT_SHARP,         "sharp"         },
         { RC_BIT_MCE_KBD,       "mce_kbd"       },
         { RC_BIT_LIRC,          "lirc"          },
+        { RC_BIT_XMP,           "xmp"           },
 };
 
 /**