4 files changed, 382 insertions, 0 deletions

diff --git a/drivers/media/IR/Kconfig b/drivers/media/IR/Kconfig
index 0c557b8cc932..ba81bda3513d 100644
--- a/drivers/media/IR/Kconfig
+++ b/drivers/media/IR/Kconfig
@@ -18,3 +18,12 @@ config IR_NEC_DECODER
         ---help---
            Enable this option if you have IR with NEC protocol, and
            if the IR is decoded in software
+
+config IR_RC5_DECODER
+        tristate "Enable IR raw decoder for RC-5 protocol"
+        depends on IR_CORE
+        default y
+
+        ---help---
+           Enable this option if you have IR with RC-5 protocol, and
+           if the IR is decoded in software
diff --git a/drivers/media/IR/Makefile b/drivers/media/IR/Makefile
index 0e3f912054ca..62e12d5c443a 100644
--- a/drivers/media/IR/Makefile
+++ b/drivers/media/IR/Makefile
@@ -6,3 +6,4 @@ obj-y += keymaps/
 obj-$(CONFIG_IR_CORE) += ir-core.o
 obj-$(CONFIG_VIDEO_IR) += ir-common.o
 obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o
+obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o
diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c
index 59f20541b03e..617e437e2beb 100644
--- a/drivers/media/IR/ir-raw-event.c
+++ b/drivers/media/IR/ir-raw-event.c
@@ -200,6 +200,7 @@ static void init_decoders(struct work_struct *work)
         /* Load the decoder modules */
 
         load_nec_decode();
+        load_rc5_decode();
 
         /* If needed, we may later add some init code. In this case,
            it is needed to change the CONFIG_MODULE test at ir-core.h
diff --git a/drivers/media/IR/ir-rc5-decoder.c b/drivers/media/IR/ir-rc5-decoder.c
new file mode 100644
index 000000000000..4b7eafecd842
--- /dev/null
+++ b/drivers/media/IR/ir-rc5-decoder.c
@@ -0,0 +1,371 @@
+/* ir-rc5-decoder.c - handle RC-5 IR Pulse/Space protocol
+ *
+ * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@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 only handles 14 bits RC-5 protocols. There are other variants
+ * that use a different number of bits. This is currently unsupported
+ */
+
+#include <media/ir-core.h>
+
+#define RC5_NBITS               14
+#define RC5_HALFBIT             888888 /* ns */
+#define RC5_BIT                 (RC5_HALFBIT * 2)
+#define RC5_DURATION            (RC5_BIT * RC5_NBITS)
+
+#define is_rc5_halfbit(nsec) ((ev->delta.tv_nsec >= RC5_HALFBIT / 2) &&    \
+                      (ev->delta.tv_nsec < RC5_HALFBIT + RC5_HALFBIT / 2))
+
+#define n_half(nsec) ((ev->delta.tv_nsec + RC5_HALFBIT / 2) / RC5_HALFBIT)
+
+/* Used to register rc5_decoder clients */
+static LIST_HEAD(decoder_list);
+static spinlock_t decoder_lock;
+
+enum rc5_state {
+        STATE_INACTIVE,
+        STATE_START2_SPACE,
+        STATE_START2_MARK,
+        STATE_MARKSPACE,
+        STATE_TRAILER_MARK,
+};
+
+static char *st_name[] = {
+        "Inactive",
+        "start2 sapce",
+        "start2 mark",
+        "mark",
+        "space",
+        "trailer"
+};
+
+struct rc5_code {
+        u8      address;
+        u8      command;
+};
+
+struct decoder_data {
+        struct list_head        list;
+        struct ir_input_dev     *ir_dev;
+        int                     enabled:1;
+
+        /* State machine control */
+        enum rc5_state          state;
+        struct rc5_code         rc5_code;
+        unsigned                n_half;
+        unsigned                count;
+};
+
+
+/**
+ * get_decoder_data()   - gets decoder data
+ * @input_dev:  input device
+ *
+ * Returns the struct decoder_data that corresponds to a device
+ */
+
+static struct decoder_data *get_decoder_data(struct  ir_input_dev *ir_dev)
+{
+        struct decoder_data *data = NULL;
+
+        spin_lock(&decoder_lock);
+        list_for_each_entry(data, &decoder_list, list) {
+                if (data->ir_dev == ir_dev)
+                        break;
+        }
+        spin_unlock(&decoder_lock);
+        return data;
+}
+
+static ssize_t store_enabled(struct device *d,
+                             struct device_attribute *mattr,
+                             const char *buf,
+                             size_t len)
+{
+        unsigned long value;
+        struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+        struct decoder_data *data = get_decoder_data(ir_dev);
+
+        if (!data)
+                return -EINVAL;
+
+        if (strict_strtoul(buf, 10, &value) || value > 1)
+                return -EINVAL;
+
+        data->enabled = value;
+
+        return len;
+}
+
+static ssize_t show_enabled(struct device *d,
+                             struct device_attribute *mattr, char *buf)
+{
+        struct ir_input_dev *ir_dev = dev_get_drvdata(d);
+        struct decoder_data *data = get_decoder_data(ir_dev);
+
+        if (!data)
+                return -EINVAL;
+
+        if (data->enabled)
+                return sprintf(buf, "1\n");
+        else
+        return sprintf(buf, "0\n");
+}
+
+static DEVICE_ATTR(enabled, S_IRUGO | S_IWUSR, show_enabled, store_enabled);
+
+static struct attribute *decoder_attributes[] = {
+        &dev_attr_enabled.attr,
+        NULL
+};
+
+static struct attribute_group decoder_attribute_group = {
+        .name   = "rc5_decoder",
+        .attrs  = decoder_attributes,
+};
+
+/**
+ * handle_event() - Decode one RC-5 pulse or space
+ * @input_dev:  the struct input_dev descriptor of the device
+ * @ev:         event array with type/duration of pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
+ */
+static int handle_event(struct input_dev *input_dev,
+                        struct ir_raw_event *ev)
+{
+        struct decoder_data *data;
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        int bit, last_bit, n_half;
+
+        data = get_decoder_data(ir_dev);
+        if (!data)
+                return -EINVAL;
+
+        /* Except for the initial event, what matters is the previous bit */
+        bit = (ev->type & IR_PULSE) ? 1 : 0;
+
+        last_bit = !bit;
+
+        /* Discards spurious space last_bits when inactive */
+
+        /* Very long delays are considered as start events */
+        if (ev->delta.tv_nsec > RC5_DURATION + RC5_HALFBIT / 2)
+                data->state = STATE_INACTIVE;
+
+        if (ev->type & IR_START_EVENT)
+                data->state = STATE_INACTIVE;
+
+        switch (data->state) {
+        case STATE_INACTIVE:
+IR_dprintk(1, "currently inative. Received bit (%s) @%luus\n",
+        last_bit ? "pulse" : "space",
+        (ev->delta.tv_nsec + 500) / 1000);
+
+                /* Discards the initial start space */
+                if (bit)
+                        return 0;
+                data->count = 0;
+                data->n_half = 0;
+                memset (&data->rc5_code, 0, sizeof(data->rc5_code));
+
+                data->state = STATE_START2_SPACE;
+                return 0;
+        case STATE_START2_SPACE:
+                if (last_bit)
+                        goto err;
+                if (!is_rc5_halfbit(ev->delta.tv_nsec))
+                        goto err;
+                data->state = STATE_START2_MARK;
+                return 0;
+        case STATE_START2_MARK:
+                if (!last_bit)
+                        goto err;
+
+                if (!is_rc5_halfbit(ev->delta.tv_nsec))
+                        goto err;
+
+                data->state = STATE_MARKSPACE;
+                return 0;
+        case STATE_MARKSPACE:
+                n_half = n_half(ev->delta.tv_nsec);
+                if (n_half < 1 || n_half > 3) {
+                        IR_dprintk(1, "Decode failed at %d-th bit (%s) @%luus\n",
+                                data->count,
+                                last_bit ? "pulse" : "space",
+                                (ev->delta.tv_nsec + 500) / 1000);
+printk("%d halves\n", n_half);
+                        goto err2;
+                }
+                data->n_half += n_half;
+
+                if (!last_bit)
+                        return 0;
+
+                /* Got one complete mark/space cycle */
+
+                bit = ((data->count + 1) * 2)/ data->n_half;
+
+printk("%d halves, %d bits\n", n_half, bit);
+
+#if 1 /* SANITY check - while testing the decoder */
+                if (bit > 1) {
+                        IR_dprintk(1, "Decoder HAS failed at %d-th bit (%s) @%luus\n",
+                                data->count,
+                                last_bit ? "pulse" : "space",
+                                (ev->delta.tv_nsec + 500) / 1000);
+
+                        goto err2;
+                }
+#endif
+                /* Ok, we've got a valid bit. proccess it */
+                if (bit) {
+                        int shift = data->count;
+
+                        /*
+                         * RC-5 transmit bytes on this temporal order:
+                         * address | not address | command | not command
+                         */
+                        if (shift < 8) {
+                                data->rc5_code.address |= 1 << shift;
+                        } else {
+                                data->rc5_code.command |= 1 << (shift - 8);
+                        }
+                }
+                IR_dprintk(1, "RC-5: bit #%d: %d (%d)\n",
+                                data->count, bit, data->n_half);
+                if (++data->count >= RC5_NBITS) {
+                        u32 scancode;
+                        scancode = data->rc5_code.address << 8 |
+                                        data->rc5_code.command;
+                        IR_dprintk(1, "RC-5 scancode 0x%04x\n", scancode);
+
+                        ir_keydown(input_dev, scancode, 0);
+
+                        data->state = STATE_TRAILER_MARK;
+                }
+                return 0;
+        case STATE_TRAILER_MARK:
+                if (!last_bit)
+                        goto err;
+                data->state = STATE_INACTIVE;
+                return 0;
+        }
+
+err:
+        IR_dprintk(1, "RC-5 decoded failed at state %s (%s) @ %luus\n",
+                   st_name[data->state],
+                   bit ? "pulse" : "space",
+                   (ev->delta.tv_nsec + 500) / 1000);
+err2:
+        data->state = STATE_INACTIVE;
+        return -EINVAL;
+}
+
+/**
+ * ir_rc5_decode() - Decodes all RC-5 pulsecodes on a given array
+ * @input_dev:  the struct input_dev descriptor of the device
+ * @evs:        event array with type/duration of pulse/space
+ * @len:        length of the array
+ * This function returns the number of decoded pulses
+ */
+static int ir_rc5_decode(struct input_dev *input_dev,
+                         struct ir_raw_event *evs,
+                         int len)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        struct decoder_data *data;
+        int pos = 0;
+        int rc = 0;
+
+        data = get_decoder_data(ir_dev);
+        if (!data || !data->enabled)
+                return 0;
+
+        for (pos = 0; pos < len; pos++)
+                handle_event(input_dev, &evs[pos]);
+
+        return rc;
+}
+
+static int ir_rc5_register(struct input_dev *input_dev)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        struct decoder_data *data;
+        int rc;
+
+        rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+        if (rc < 0)
+                return rc;
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data) {
+                sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+                return -ENOMEM;
+        }
+
+        data->ir_dev = ir_dev;
+        data->enabled = 1;
+
+        spin_lock(&decoder_lock);
+        list_add_tail(&data->list, &decoder_list);
+        spin_unlock(&decoder_lock);
+
+        return 0;
+}
+
+static int ir_rc5_unregister(struct input_dev *input_dev)
+{
+        struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+        static struct decoder_data *data;
+
+        data = get_decoder_data(ir_dev);
+        if (!data)
+                return 0;
+
+        sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
+
+        spin_lock(&decoder_lock);
+        list_del(&data->list);
+        spin_unlock(&decoder_lock);
+
+        return 0;
+}
+
+static struct ir_raw_handler rc5_handler = {
+        .decode         = ir_rc5_decode,
+        .raw_register   = ir_rc5_register,
+        .raw_unregister = ir_rc5_unregister,
+};
+
+static int __init ir_rc5_decode_init(void)
+{
+        ir_raw_handler_register(&rc5_handler);
+
+        printk(KERN_INFO "IR RC-5 protocol handler initialized\n");
+        return 0;
+}
+
+static void __exit ir_rc5_decode_exit(void)
+{
+        ir_raw_handler_unregister(&rc5_handler);
+}
+
+module_init(ir_rc5_decode_init);
+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");