V4L/DVB: ir-core: dynamically load the compiled IR protocols

Instead of hardcoding the protocols into ir-core, add a register interface
for the IR protocol decoders, and convert ir-nec-decoder into a client of
ir-core.

With this approach, it is possible to dynamically load the needed IR protocols,
and to add a RAW IR interface module, registered as one IR raw protocol decoder.

This patch opens a way to register a lirc_dev interface to work as an userspace
IR protocol decoder.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

5 files changed, 101 insertions, 10 deletions

diff --git a/drivers/media/IR/Kconfig b/drivers/media/IR/Kconfig
index 4dde7d180a32..de410d46ae26 100644
--- a/drivers/media/IR/Kconfig
+++ b/drivers/media/IR/Kconfig
@@ -7,3 +7,12 @@ config VIDEO_IR
         tristate
         depends on IR_CORE
         default IR_CORE
+
+config IR_NEC_DECODER
+        tristate "Enable IR raw decoder for NEC protocol"
+        depends on IR_CORE
+        default y
+
+        ---help---
+           Enable this option if you have IR with NEC protocol, and
+           if the IR is decoded in software
diff --git a/drivers/media/IR/Makefile b/drivers/media/IR/Makefile
index 18794c7b0ea6..6140b2712c8a 100644
--- a/drivers/media/IR/Makefile
+++ b/drivers/media/IR/Makefile
@@ -1,5 +1,6 @@
 ir-common-objs  := ir-functions.o ir-keymaps.o
-ir-core-objs    := ir-keytable.o ir-sysfs.o ir-raw-event.o ir-nec-decoder.o
+ir-core-objs    := ir-keytable.o ir-sysfs.o ir-raw-event.o
 
 obj-$(CONFIG_IR_CORE) += ir-core.o
 obj-$(CONFIG_VIDEO_IR) += ir-common.o
+obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o
diff --git a/drivers/media/IR/ir-nec-decoder.c b/drivers/media/IR/ir-nec-decoder.c
index 104482a6991e..c9a986dd57fd 100644
--- a/drivers/media/IR/ir-nec-decoder.c
+++ b/drivers/media/IR/ir-nec-decoder.c
@@ -1,4 +1,4 @@
-/* ir-raw-event.c - handle IR Pulse/Space event
+/* ir-nec-decoder.c - handle NEC IR Pulse/Space protocol
  *
  * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
  *
@@ -147,7 +147,7 @@ static int __ir_nec_decode(struct input_dev *input_dev,
                 if (++count == 32)
                         break;
         }
-        *pos++;
+        (*pos)++;
 
         /*
          * Fixme: may need to accept Extended NEC protocol?
@@ -181,9 +181,9 @@ err:
  * This function returns the number of decoded pulses or -EINVAL if no
  * pulse got decoded
  */
-int ir_nec_decode(struct input_dev *input_dev,
-                           struct ir_raw_event *evs,
-                           int len)
+static int ir_nec_decode(struct input_dev *input_dev,
+                         struct ir_raw_event *evs,
+                         int len)
 {
         int pos = 0;
         int rc = 0;
@@ -198,4 +198,27 @@ int ir_nec_decode(struct input_dev *input_dev,
         return rc;
 }
 
-EXPORT_SYMBOL_GPL(ir_nec_decode);
+static struct ir_raw_handler nec_handler = {
+        .decode = ir_nec_decode,
+};
+
+static int __init ir_nec_decode_init(void)
+{
+        ir_raw_handler_register(&nec_handler);
+
+        printk(KERN_INFO "IR NEC protocol handler initialized\n");
+        return 0;
+}
+
+static void __exit ir_nec_decode_exit(void)
+{
+        ir_raw_handler_unregister(&nec_handler);
+}
+
+module_init(ir_nec_decode_init);
+module_exit(ir_nec_decode_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
+MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
+MODULE_DESCRIPTION("NEC IR protocol decoder");
diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c
index 0ae55433cef9..3eae128400ea 100644
--- a/drivers/media/IR/ir-raw-event.c
+++ b/drivers/media/IR/ir-raw-event.c
@@ -13,10 +13,18 @@
  */
 
 #include <media/ir-core.h>
+#include <linux/workqueue.h>
 
 /* Define the max number of bit transitions per IR keycode */
 #define MAX_IR_EVENT_SIZE       256
 
+/* Used to handle IR raw handler extensions */
+static LIST_HEAD(ir_raw_handler_list);
+static DEFINE_MUTEX(ir_raw_handler_lock);
+
+/* Used to load the decoders */
+static struct work_struct wq_load;
+
 static void ir_keyup_timer(unsigned long data)
 {
         struct input_dev *input_dev = (struct input_dev *)data;
@@ -101,6 +109,7 @@ int ir_raw_event_handle(struct input_dev *input_dev)
         int                             rc;
         struct ir_raw_event             *evs;
         int                             len, i;
+        struct ir_raw_handler           *ir_raw_handler;
 
         /*
          * Store the events into a temporary buffer. This allows calling more than
@@ -122,10 +131,56 @@ int ir_raw_event_handle(struct input_dev *input_dev)
                         evs[i].type, (evs[i].delta.tv_nsec + 500) / 1000);
         }
 
-        rc = ir_nec_decode(input_dev, evs, len);
+        /*
+         * Call all ir decoders. This allows decoding the same event with
+         * more than one protocol handler.
+         * FIXME: better handle the returned code: does it make sense to use
+         * other decoders, if the first one already handled the IR?
+         */
+        list_for_each_entry(ir_raw_handler, &ir_raw_handler_list, list) {
+                rc = ir_raw_handler->decode(input_dev, evs, len);
+        }
 
         kfree(evs);
 
         return rc;
 }
 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
+
+/*
+ * Extension interface - used to register the IR decoders
+ */
+
+int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
+{
+        mutex_lock(&ir_raw_handler_lock);
+        list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
+        mutex_unlock(&ir_raw_handler_lock);
+        return 0;
+}
+EXPORT_SYMBOL(ir_raw_handler_register);
+
+void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
+{
+        mutex_lock(&ir_raw_handler_lock);
+        list_del(&ir_raw_handler->list);
+        mutex_unlock(&ir_raw_handler_lock);
+}
+EXPORT_SYMBOL(ir_raw_handler_unregister);
+
+static void init_decoders(struct work_struct *work)
+{
+        /* Load the decoder modules */
+
+        load_nec_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
+         */
+}
+
+void ir_raw_init(void)
+{
+        INIT_WORK(&wq_load, init_decoders);
+        schedule_work(&wq_load);
+}
\ No newline at end of file
diff --git a/drivers/media/IR/ir-sysfs.c b/drivers/media/IR/ir-sysfs.c
index 253e66999f18..2279d5594b05 100644
--- a/drivers/media/IR/ir-sysfs.c
+++ b/drivers/media/IR/ir-sysfs.c
@@ -1,6 +1,6 @@
 /* ir-register.c - handle IR scancode->keycode tables
  *
- * Copyright (C) 2009 by Mauro Carvalho Chehab <mchehab@redhat.com>
+ * Copyright (C) 2009-2010 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
@@ -28,7 +28,7 @@ static char *ir_devnode(struct device *dev, mode_t *mode)
         return kasprintf(GFP_KERNEL, "irrcv/%s", dev_name(dev));
 }
 
-struct class ir_input_class = {
+static struct class ir_input_class = {
         .name           = "irrcv",
         .devnode        = ir_devnode,
 };
@@ -251,6 +251,9 @@ static int __init ir_core_init(void)
                 return rc;
         }
 
+        /* Initialize/load the decoders that will be used */
+        ir_raw_init();
+
         return 0;
 }