Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2095 insertions, 0 deletions

diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
new file mode 100644
index 0000000000..6bdad63418
--- /dev/null
+++ b/drivers/media/rc/rc-main.c
@@ -0,0 +1,2095 @@
+// SPDX-License-Identifier: GPL-2.0
+// rc-main.c - Remote Controller core module
+//
+// Copyright (C) 2009-2010 by Mauro Carvalho Chehab
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <media/rc-core.h>
+#include <linux/bsearch.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include "rc-core-priv.h"
+
+/* Sizes are in bytes, 256 bytes allows for 32 entries on x64 */
+#define IR_TAB_MIN_SIZE	256
+#define IR_TAB_MAX_SIZE	8192
+
+static const struct {
+	const char *name;
+	unsigned int repeat_period;
+	unsigned int scancode_bits;
+} protocols[] = {
+	[RC_PROTO_UNKNOWN] = { .name = "unknown", .repeat_period = 125 },
+	[RC_PROTO_OTHER] = { .name = "other", .repeat_period = 125 },
+	[RC_PROTO_RC5] = { .name = "rc-5",
+		.scancode_bits = 0x1f7f, .repeat_period = 114 },
+	[RC_PROTO_RC5X_20] = { .name = "rc-5x-20",
+		.scancode_bits = 0x1f7f3f, .repeat_period = 114 },
+	[RC_PROTO_RC5_SZ] = { .name = "rc-5-sz",
+		.scancode_bits = 0x2fff, .repeat_period = 114 },
+	[RC_PROTO_JVC] = { .name = "jvc",
+		.scancode_bits = 0xffff, .repeat_period = 125 },
+	[RC_PROTO_SONY12] = { .name = "sony-12",
+		.scancode_bits = 0x1f007f, .repeat_period = 100 },
+	[RC_PROTO_SONY15] = { .name = "sony-15",
+		.scancode_bits = 0xff007f, .repeat_period = 100 },
+	[RC_PROTO_SONY20] = { .name = "sony-20",
+		.scancode_bits = 0x1fff7f, .repeat_period = 100 },
+	[RC_PROTO_NEC] = { .name = "nec",
+		.scancode_bits = 0xffff, .repeat_period = 110 },
+	[RC_PROTO_NECX] = { .name = "nec-x",
+		.scancode_bits = 0xffffff, .repeat_period = 110 },
+	[RC_PROTO_NEC32] = { .name = "nec-32",
+		.scancode_bits = 0xffffffff, .repeat_period = 110 },
+	[RC_PROTO_SANYO] = { .name = "sanyo",
+		.scancode_bits = 0x1fffff, .repeat_period = 125 },
+	[RC_PROTO_MCIR2_KBD] = { .name = "mcir2-kbd",
+		.scancode_bits = 0xffffff, .repeat_period = 100 },
+	[RC_PROTO_MCIR2_MSE] = { .name = "mcir2-mse",
+		.scancode_bits = 0x1fffff, .repeat_period = 100 },
+	[RC_PROTO_RC6_0] = { .name = "rc-6-0",
+		.scancode_bits = 0xffff, .repeat_period = 114 },
+	[RC_PROTO_RC6_6A_20] = { .name = "rc-6-6a-20",
+		.scancode_bits = 0xfffff, .repeat_period = 114 },
+	[RC_PROTO_RC6_6A_24] = { .name = "rc-6-6a-24",
+		.scancode_bits = 0xffffff, .repeat_period = 114 },
+	[RC_PROTO_RC6_6A_32] = { .name = "rc-6-6a-32",
+		.scancode_bits = 0xffffffff, .repeat_period = 114 },
+	[RC_PROTO_RC6_MCE] = { .name = "rc-6-mce",
+		.scancode_bits = 0xffff7fff, .repeat_period = 114 },
+	[RC_PROTO_SHARP] = { .name = "sharp",
+		.scancode_bits = 0x1fff, .repeat_period = 125 },
+	[RC_PROTO_XMP] = { .name = "xmp", .repeat_period = 125 },
+	[RC_PROTO_CEC] = { .name = "cec", .repeat_period = 0 },
+	[RC_PROTO_IMON] = { .name = "imon",
+		.scancode_bits = 0x7fffffff, .repeat_period = 114 },
+	[RC_PROTO_RCMM12] = { .name = "rc-mm-12",
+		.scancode_bits = 0x00000fff, .repeat_period = 114 },
+	[RC_PROTO_RCMM24] = { .name = "rc-mm-24",
+		.scancode_bits = 0x00ffffff, .repeat_period = 114 },
+	[RC_PROTO_RCMM32] = { .name = "rc-mm-32",
+		.scancode_bits = 0xffffffff, .repeat_period = 114 },
+	[RC_PROTO_XBOX_DVD] = { .name = "xbox-dvd", .repeat_period = 64 },
+};
+
+/* Used to keep track of known keymaps */
+static LIST_HEAD(rc_map_list);
+static DEFINE_SPINLOCK(rc_map_lock);
+static struct led_trigger *led_feedback;
+
+/* Used to keep track of rc devices */
+static DEFINE_IDA(rc_ida);
+
+static struct rc_map_list *seek_rc_map(const char *name)
+{
+	struct rc_map_list *map = NULL;
+
+	spin_lock(&rc_map_lock);
+	list_for_each_entry(map, &rc_map_list, list) {
+		if (!strcmp(name, map->map.name)) {
+			spin_unlock(&rc_map_lock);
+			return map;
+		}
+	}
+	spin_unlock(&rc_map_lock);
+
+	return NULL;
+}
+
+struct rc_map *rc_map_get(const char *name)
+{
+
+	struct rc_map_list *map;
+
+	map = seek_rc_map(name);
+#ifdef CONFIG_MODULES
+	if (!map) {
+		int rc = request_module("%s", name);
+		if (rc < 0) {
+			pr_err("Couldn't load IR keymap %s\n", name);
+			return NULL;
+		}
+		msleep(20);	/* Give some time for IR to register */
+
+		map = seek_rc_map(name);
+	}
+#endif
+	if (!map) {
+		pr_err("IR keymap %s not found\n", name);
+		return NULL;
+	}
+
+	printk(KERN_INFO "Registered IR keymap %s\n", map->map.name);
+
+	return &map->map;
+}
+EXPORT_SYMBOL_GPL(rc_map_get);
+
+int rc_map_register(struct rc_map_list *map)
+{
+	spin_lock(&rc_map_lock);
+	list_add_tail(&map->list, &rc_map_list);
+	spin_unlock(&rc_map_lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rc_map_register);
+
+void rc_map_unregister(struct rc_map_list *map)
+{
+	spin_lock(&rc_map_lock);
+	list_del(&map->list);
+	spin_unlock(&rc_map_lock);
+}
+EXPORT_SYMBOL_GPL(rc_map_unregister);
+
+
+static struct rc_map_table empty[] = {
+	{ 0x2a, KEY_COFFEE },
+};
+
+static struct rc_map_list empty_map = {
+	.map = {
+		.scan     = empty,
+		.size     = ARRAY_SIZE(empty),
+		.rc_proto = RC_PROTO_UNKNOWN,	/* Legacy IR type */
+		.name     = RC_MAP_EMPTY,
+	}
+};
+
+/**
+ * scancode_to_u64() - converts scancode in &struct input_keymap_entry
+ * @ke: keymap entry containing scancode to be converted.
+ * @scancode: pointer to the location where converted scancode should
+ *	be stored.
+ *
+ * This function is a version of input_scancode_to_scalar specialized for
+ * rc-core.
+ */
+static int scancode_to_u64(const struct input_keymap_entry *ke, u64 *scancode)
+{
+	switch (ke->len) {
+	case 1:
+		*scancode = *((u8 *)ke->scancode);
+		break;
+
+	case 2:
+		*scancode = *((u16 *)ke->scancode);
+		break;
+
+	case 4:
+		*scancode = *((u32 *)ke->scancode);
+		break;
+
+	case 8:
+		*scancode = *((u64 *)ke->scancode);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * ir_create_table() - initializes a scancode table
+ * @dev:	the rc_dev device
+ * @rc_map:	the rc_map to initialize
+ * @name:	name to assign to the table
+ * @rc_proto:	ir type to assign to the new table
+ * @size:	initial size of the table
+ *
+ * This routine will initialize the rc_map and will allocate
+ * memory to hold at least the specified number of elements.
+ *
+ * return:	zero on success or a negative error code
+ */
+static int ir_create_table(struct rc_dev *dev, struct rc_map *rc_map,
+			   const char *name, u64 rc_proto, size_t size)
+{
+	rc_map->name = kstrdup(name, GFP_KERNEL);
+	if (!rc_map->name)
+		return -ENOMEM;
+	rc_map->rc_proto = rc_proto;
+	rc_map->alloc = roundup_pow_of_two(size * sizeof(struct rc_map_table));
+	rc_map->size = rc_map->alloc / sizeof(struct rc_map_table);
+	rc_map->scan = kmalloc(rc_map->alloc, GFP_KERNEL);
+	if (!rc_map->scan) {
+		kfree(rc_map->name);
+		rc_map->name = NULL;
+		return -ENOMEM;
+	}
+
+	dev_dbg(&dev->dev, "Allocated space for %u keycode entries (%u bytes)\n",
+		rc_map->size, rc_map->alloc);
+	return 0;
+}
+
+/**
+ * ir_free_table() - frees memory allocated by a scancode table
+ * @rc_map:	the table whose mappings need to be freed
+ *
+ * This routine will free memory alloctaed for key mappings used by given
+ * scancode table.
+ */
+static void ir_free_table(struct rc_map *rc_map)
+{
+	rc_map->size = 0;
+	kfree(rc_map->name);
+	rc_map->name = NULL;
+	kfree(rc_map->scan);
+	rc_map->scan = NULL;
+}
+
+/**
+ * ir_resize_table() - resizes a scancode table if necessary
+ * @dev:	the rc_dev device
+ * @rc_map:	the rc_map to resize
+ * @gfp_flags:	gfp flags to use when allocating memory
+ *
+ * This routine will shrink the rc_map if it has lots of
+ * unused entries and grow it if it is full.
+ *
+ * return:	zero on success or a negative error code
+ */
+static int ir_resize_table(struct rc_dev *dev, struct rc_map *rc_map,
+			   gfp_t gfp_flags)
+{
+	unsigned int oldalloc = rc_map->alloc;
+	unsigned int newalloc = oldalloc;
+	struct rc_map_table *oldscan = rc_map->scan;
+	struct rc_map_table *newscan;
+
+	if (rc_map->size == rc_map->len) {
+		/* All entries in use -> grow keytable */
+		if (rc_map->alloc >= IR_TAB_MAX_SIZE)
+			return -ENOMEM;
+
+		newalloc *= 2;
+		dev_dbg(&dev->dev, "Growing table to %u bytes\n", newalloc);
+	}
+
+	if ((rc_map->len * 3 < rc_map->size) && (oldalloc > IR_TAB_MIN_SIZE)) {
+		/* Less than 1/3 of entries in use -> shrink keytable */
+		newalloc /= 2;
+		dev_dbg(&dev->dev, "Shrinking table to %u bytes\n", newalloc);
+	}
+
+	if (newalloc == oldalloc)
+		return 0;
+
+	newscan = kmalloc(newalloc, gfp_flags);
+	if (!newscan)
+		return -ENOMEM;
+
+	memcpy(newscan, rc_map->scan, rc_map->len * sizeof(struct rc_map_table));
+	rc_map->scan = newscan;
+	rc_map->alloc = newalloc;
+	rc_map->size = rc_map->alloc / sizeof(struct rc_map_table);
+	kfree(oldscan);
+	return 0;
+}
+
+/**
+ * ir_update_mapping() - set a keycode in the scancode->keycode table
+ * @dev:	the struct rc_dev device descriptor
+ * @rc_map:	scancode table to be adjusted
+ * @index:	index of the mapping that needs to be updated
+ * @new_keycode: the desired keycode
+ *
+ * This routine is used to update scancode->keycode mapping at given
+ * position.
+ *
+ * return:	previous keycode assigned to the mapping
+ *
+ */
+static unsigned int ir_update_mapping(struct rc_dev *dev,
+				      struct rc_map *rc_map,
+				      unsigned int index,
+				      unsigned int new_keycode)
+{
+	int old_keycode = rc_map->scan[index].keycode;
+	int i;
+
+	/* Did the user wish to remove the mapping? */
+	if (new_keycode == KEY_RESERVED || new_keycode == KEY_UNKNOWN) {
+		dev_dbg(&dev->dev, "#%d: Deleting scan 0x%04llx\n",
+			index, rc_map->scan[index].scancode);
+		rc_map->len--;
+		memmove(&rc_map->scan[index], &rc_map->scan[index+ 1],
+			(rc_map->len - index) * sizeof(struct rc_map_table));
+	} else {
+		dev_dbg(&dev->dev, "#%d: %s scan 0x%04llx with key 0x%04x\n",
+			index,
+			old_keycode == KEY_RESERVED ? "New" : "Replacing",
+			rc_map->scan[index].scancode, new_keycode);
+		rc_map->scan[index].keycode = new_keycode;
+		__set_bit(new_keycode, dev->input_dev->keybit);
+	}
+
+	if (old_keycode != KEY_RESERVED) {
+		/* A previous mapping was updated... */
+		__clear_bit(old_keycode, dev->input_dev->keybit);
+		/* ... but another scancode might use the same keycode */
+		for (i = 0; i < rc_map->len; i++) {
+			if (rc_map->scan[i].keycode == old_keycode) {
+				__set_bit(old_keycode, dev->input_dev->keybit);
+				break;
+			}
+		}
+
+		/* Possibly shrink the keytable, failure is not a problem */
+		ir_resize_table(dev, rc_map, GFP_ATOMIC);
+	}
+
+	return old_keycode;
+}
+
+/**
+ * ir_establish_scancode() - set a keycode in the scancode->keycode table
+ * @dev:	the struct rc_dev device descriptor
+ * @rc_map:	scancode table to be searched
+ * @scancode:	the desired scancode
+ * @resize:	controls whether we allowed to resize the table to
+ *		accommodate not yet present scancodes
+ *
+ * This routine is used to locate given scancode in rc_map.
+ * If scancode is not yet present the routine will allocate a new slot
+ * for it.
+ *
+ * return:	index of the mapping containing scancode in question
+ *		or -1U in case of failure.
+ */
+static unsigned int ir_establish_scancode(struct rc_dev *dev,
+					  struct rc_map *rc_map,
+					  u64 scancode, bool resize)
+{
+	unsigned int i;
+
+	/*
+	 * Unfortunately, some hardware-based IR decoders don't provide
+	 * all bits for the complete IR code. In general, they provide only
+	 * the command part of the IR code. Yet, as it is possible to replace
+	 * the provided IR with another one, it is needed to allow loading
+	 * IR tables from other remotes. So, we support specifying a mask to
+	 * indicate the valid bits of the scancodes.
+	 */
+	if (dev->scancode_mask)
+		scancode &= dev->scancode_mask;
+
+	/* First check if we already have a mapping for this ir command */
+	for (i = 0; i < rc_map->len; i++) {
+		if (rc_map->scan[i].scancode == scancode)
+			return i;
+
+		/* Keytable is sorted from lowest to highest scancode */
+		if (rc_map->scan[i].scancode >= scancode)
+			break;
+	}
+
+	/* No previous mapping found, we might need to grow the table */
+	if (rc_map->size == rc_map->len) {
+		if (!resize || ir_resize_table(dev, rc_map, GFP_ATOMIC))
+			return -1U;
+	}
+
+	/* i is the proper index to insert our new keycode */
+	if (i < rc_map->len)
+		memmove(&rc_map->scan[i + 1], &rc_map->scan[i],
+			(rc_map->len - i) * sizeof(struct rc_map_table));
+	rc_map->scan[i].scancode = scancode;
+	rc_map->scan[i].keycode = KEY_RESERVED;
+	rc_map->len++;
+
+	return i;
+}
+
+/**
+ * ir_setkeycode() - set a keycode in the scancode->keycode table
+ * @idev:	the struct input_dev device descriptor
+ * @ke:		Input keymap entry
+ * @old_keycode: result
+ *
+ * This routine is used to handle evdev EVIOCSKEY ioctl.
+ *
+ * return:	-EINVAL if the keycode could not be inserted, otherwise zero.
+ */
+static int ir_setkeycode(struct input_dev *idev,
+			 const struct input_keymap_entry *ke,
+			 unsigned int *old_keycode)
+{
+	struct rc_dev *rdev = input_get_drvdata(idev);
+	struct rc_map *rc_map = &rdev->rc_map;
+	unsigned int index;
+	u64 scancode;
+	int retval = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rc_map->lock, flags);
+
+	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
+		index = ke->index;
+		if (index >= rc_map->len) {
+			retval = -EINVAL;
+			goto out;
+		}
+	} else {
+		retval = scancode_to_u64(ke, &scancode);
+		if (retval)
+			goto out;
+
+		index = ir_establish_scancode(rdev, rc_map, scancode, true);
+		if (index >= rc_map->len) {
+			retval = -ENOMEM;
+			goto out;
+		}
+	}
+
+	*old_keycode = ir_update_mapping(rdev, rc_map, index, ke->keycode);
+
+out:
+	spin_unlock_irqrestore(&rc_map->lock, flags);
+	return retval;
+}
+
+/**
+ * ir_setkeytable() - sets several entries in the scancode->keycode table
+ * @dev:	the struct rc_dev device descriptor
+ * @from:	the struct rc_map to copy entries from
+ *
+ * This routine is used to handle table initialization.
+ *
+ * return:	-ENOMEM if all keycodes could not be inserted, otherwise zero.
+ */
+static int ir_setkeytable(struct rc_dev *dev, const struct rc_map *from)
+{
+	struct rc_map *rc_map = &dev->rc_map;
+	unsigned int i, index;
+	int rc;
+
+	rc = ir_create_table(dev, rc_map, from->name, from->rc_proto,
+			     from->size);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < from->size; i++) {
+		index = ir_establish_scancode(dev, rc_map,
+					      from->scan[i].scancode, false);
+		if (index >= rc_map->len) {
+			rc = -ENOMEM;
+			break;
+		}
+
+		ir_update_mapping(dev, rc_map, index,
+				  from->scan[i].keycode);
+	}
+
+	if (rc)
+		ir_free_table(rc_map);
+
+	return rc;
+}
+
+static int rc_map_cmp(const void *key, const void *elt)
+{
+	const u64 *scancode = key;
+	const struct rc_map_table *e = elt;
+
+	if (*scancode < e->scancode)
+		return -1;
+	else if (*scancode > e->scancode)
+		return 1;
+	return 0;
+}
+
+/**
+ * ir_lookup_by_scancode() - locate mapping by scancode
+ * @rc_map:	the struct rc_map to search
+ * @scancode:	scancode to look for in the table
+ *
+ * This routine performs binary search in RC keykeymap table for
+ * given scancode.
+ *
+ * return:	index in the table, -1U if not found
+ */
+static unsigned int ir_lookup_by_scancode(const struct rc_map *rc_map,
+					  u64 scancode)
+{
+	struct rc_map_table *res;
+
+	res = bsearch(&scancode, rc_map->scan, rc_map->len,
+		      sizeof(struct rc_map_table), rc_map_cmp);
+	if (!res)
+		return -1U;
+	else
+		return res - rc_map->scan;
+}
+
+/**
+ * ir_getkeycode() - get a keycode from the scancode->keycode table
+ * @idev:	the struct input_dev device descriptor
+ * @ke:		Input keymap entry
+ *
+ * This routine is used to handle evdev EVIOCGKEY ioctl.
+ *
+ * return:	always returns zero.
+ */
+static int ir_getkeycode(struct input_dev *idev,
+			 struct input_keymap_entry *ke)
+{
+	struct rc_dev *rdev = input_get_drvdata(idev);
+	struct rc_map *rc_map = &rdev->rc_map;
+	struct rc_map_table *entry;
+	unsigned long flags;
+	unsigned int index;
+	u64 scancode;
+	int retval;
+
+	spin_lock_irqsave(&rc_map->lock, flags);
+
+	if (ke->flags & INPUT_KEYMAP_BY_INDEX) {
+		index = ke->index;
+	} else {
+		retval = scancode_to_u64(ke, &scancode);
+		if (retval)
+			goto out;
+
+		index = ir_lookup_by_scancode(rc_map, scancode);
+	}
+
+	if (index < rc_map->len) {
+		entry = &rc_map->scan[index];
+
+		ke->index = index;
+		ke->keycode = entry->keycode;
+		ke->len = sizeof(entry->scancode);
+		memcpy(ke->scancode, &entry->scancode, sizeof(entry->scancode));
+	} else if (!(ke->flags & INPUT_KEYMAP_BY_INDEX)) {
+		/*
+		 * We do not really know the valid range of scancodes
+		 * so let's respond with KEY_RESERVED to anything we
+		 * do not have mapping for [yet].
+		 */
+		ke->index = index;
+		ke->keycode = KEY_RESERVED;
+	} else {
+		retval = -EINVAL;
+		goto out;
+	}
+
+	retval = 0;
+
+out:
+	spin_unlock_irqrestore(&rc_map->lock, flags);
+	return retval;
+}
+
+/**
+ * rc_g_keycode_from_table() - gets the keycode that corresponds to a scancode
+ * @dev:	the struct rc_dev descriptor of the device
+ * @scancode:	the scancode to look for
+ *
+ * This routine is used by drivers which need to convert a scancode to a
+ * keycode. Normally it should not be used since drivers should have no
+ * interest in keycodes.
+ *
+ * return:	the corresponding keycode, or KEY_RESERVED
+ */
+u32 rc_g_keycode_from_table(struct rc_dev *dev, u64 scancode)
+{
+	struct rc_map *rc_map = &dev->rc_map;
+	unsigned int keycode;
+	unsigned int index;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rc_map->lock, flags);
+
+	index = ir_lookup_by_scancode(rc_map, scancode);
+	keycode = index < rc_map->len ?
+			rc_map->scan[index].keycode : KEY_RESERVED;
+
+	spin_unlock_irqrestore(&rc_map->lock, flags);
+
+	if (keycode != KEY_RESERVED)
+		dev_dbg(&dev->dev, "%s: scancode 0x%04llx keycode 0x%02x\n",
+			dev->device_name, scancode, keycode);
+
+	return keycode;
+}
+EXPORT_SYMBOL_GPL(rc_g_keycode_from_table);
+
+/**
+ * ir_do_keyup() - internal function to signal the release of a keypress
+ * @dev:	the struct rc_dev descriptor of the device
+ * @sync:	whether or not to call input_sync
+ *
+ * This function is used internally to release a keypress, it must be
+ * called with keylock held.
+ */
+static void ir_do_keyup(struct rc_dev *dev, bool sync)
+{
+	if (!dev->keypressed)
+		return;
+
+	dev_dbg(&dev->dev, "keyup key 0x%04x\n", dev->last_keycode);
+	del_timer(&dev->timer_repeat);
+	input_report_key(dev->input_dev, dev->last_keycode, 0);
+	led_trigger_event(led_feedback, LED_OFF);
+	if (sync)
+		input_sync(dev->input_dev);
+	dev->keypressed = false;
+}
+
+/**
+ * rc_keyup() - signals the release of a keypress
+ * @dev:	the struct rc_dev descriptor of the device
+ *
+ * This routine is used to signal that a key has been released on the
+ * remote control.
+ */
+void rc_keyup(struct rc_dev *dev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->keylock, flags);
+	ir_do_keyup(dev, true);
+	spin_unlock_irqrestore(&dev->keylock, flags);
+}
+EXPORT_SYMBOL_GPL(rc_keyup);
+
+/**
+ * ir_timer_keyup() - generates a keyup event after a timeout
+ *
+ * @t:		a pointer to the struct timer_list
+ *
+ * This routine will generate a keyup event some time after a keydown event
+ * is generated when no further activity has been detected.
+ */
+static void ir_timer_keyup(struct timer_list *t)
+{
+	struct rc_dev *dev = from_timer(dev, t, timer_keyup);
+	unsigned long flags;
+
+	/*
+	 * ir->keyup_jiffies is used to prevent a race condition if a
+	 * hardware interrupt occurs at this point and the keyup timer
+	 * event is moved further into the future as a result.
+	 *
+	 * The timer will then be reactivated and this function called
+	 * again in the future. We need to exit gracefully in that case
+	 * to allow the input subsystem to do its auto-repeat magic or
+	 * a keyup event might follow immediately after the keydown.
+	 */
+	spin_lock_irqsave(&dev->keylock, flags);
+	if (time_is_before_eq_jiffies(dev->keyup_jiffies))
+		ir_do_keyup(dev, true);
+	spin_unlock_irqrestore(&dev->keylock, flags);
+}
+
+/**
+ * ir_timer_repeat() - generates a repeat event after a timeout
+ *
+ * @t:		a pointer to the struct timer_list
+ *
+ * This routine will generate a soft repeat event every REP_PERIOD
+ * milliseconds.
+ */
+static void ir_timer_repeat(struct timer_list *t)
+{
+	struct rc_dev *dev = from_timer(dev, t, timer_repeat);
+	struct input_dev *input = dev->input_dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->keylock, flags);
+	if (dev->keypressed) {
+		input_event(input, EV_KEY, dev->last_keycode, 2);
+		input_sync(input);
+		if (input->rep[REP_PERIOD])
+			mod_timer(&dev->timer_repeat, jiffies +
+				  msecs_to_jiffies(input->rep[REP_PERIOD]));
+	}
+	spin_unlock_irqrestore(&dev->keylock, flags);
+}
+
+static unsigned int repeat_period(int protocol)
+{
+	if (protocol >= ARRAY_SIZE(protocols))
+		return 100;
+
+	return protocols[protocol].repeat_period;
+}
+
+/**
+ * rc_repeat() - signals that a key is still pressed
+ * @dev:	the struct rc_dev descriptor of the device
+ *
+ * This routine is used by IR decoders when a repeat message which does
+ * not include the necessary bits to reproduce the scancode has been
+ * received.
+ */
+void rc_repeat(struct rc_dev *dev)
+{
+	unsigned long flags;
+	unsigned int timeout = usecs_to_jiffies(dev->timeout) +
+		msecs_to_jiffies(repeat_period(dev->last_protocol));
+	struct lirc_scancode sc = {
+		.scancode = dev->last_scancode, .rc_proto = dev->last_protocol,
+		.keycode = dev->keypressed ? dev->last_keycode : KEY_RESERVED,
+		.flags = LIRC_SCANCODE_FLAG_REPEAT |
+			 (dev->last_toggle ? LIRC_SCANCODE_FLAG_TOGGLE : 0)
+	};
+
+	if (dev->allowed_protocols != RC_PROTO_BIT_CEC)
+		lirc_scancode_event(dev, &sc);
+
+	spin_lock_irqsave(&dev->keylock, flags);
+
+	if (dev->last_scancode <= U32_MAX) {
+		input_event(dev->input_dev, EV_MSC, MSC_SCAN,
+			    dev->last_scancode);
+		input_sync(dev->input_dev);
+	}
+
+	if (dev->keypressed) {
+		dev->keyup_jiffies = jiffies + timeout;
+		mod_timer(&dev->timer_keyup, dev->keyup_jiffies);
+	}
+
+	spin_unlock_irqrestore(&dev->keylock, flags);
+}
+EXPORT_SYMBOL_GPL(rc_repeat);
+
+/**
+ * ir_do_keydown() - internal function to process a keypress
+ * @dev:	the struct rc_dev descriptor of the device
+ * @protocol:	the protocol of the keypress
+ * @scancode:   the scancode of the keypress
+ * @keycode:    the keycode of the keypress
+ * @toggle:     the toggle value of the keypress
+ *
+ * This function is used internally to register a keypress, it must be
+ * called with keylock held.
+ */
+static void ir_do_keydown(struct rc_dev *dev, enum rc_proto protocol,
+			  u64 scancode, u32 keycode, u8 toggle)
+{
+	bool new_event = (!dev->keypressed		 ||
+			  dev->last_protocol != protocol ||
+			  dev->last_scancode != scancode ||
+			  dev->last_toggle   != toggle);
+	struct lirc_scancode sc = {
+		.scancode = scancode, .rc_proto = protocol,
+		.flags = (toggle ? LIRC_SCANCODE_FLAG_TOGGLE : 0) |
+			 (!new_event ? LIRC_SCANCODE_FLAG_REPEAT : 0),
+		.keycode = keycode
+	};
+
+	if (dev->allowed_protocols != RC_PROTO_BIT_CEC)
+		lirc_scancode_event(dev, &sc);
+
+	if (new_event && dev->keypressed)
+		ir_do_keyup(dev, false);
+
+	if (scancode <= U32_MAX)
+		input_event(dev->input_dev, EV_MSC, MSC_SCAN, scancode);
+
+	dev->last_protocol = protocol;
+	dev->last_scancode = scancode;
+	dev->last_toggle = toggle;
+	dev->last_keycode = keycode;
+
+	if (new_event && keycode != KEY_RESERVED) {
+		/* Register a keypress */
+		dev->keypressed = true;
+
+		dev_dbg(&dev->dev, "%s: key down event, key 0x%04x, protocol 0x%04x, scancode 0x%08llx\n",
+			dev->device_name, keycode, protocol, scancode);
+		input_report_key(dev->input_dev, keycode, 1);
+
+		led_trigger_event(led_feedback, LED_FULL);
+	}
+
+	/*
+	 * For CEC, start sending repeat messages as soon as the first
+	 * repeated message is sent, as long as REP_DELAY = 0 and REP_PERIOD
+	 * is non-zero. Otherwise, the input layer will generate repeat
+	 * messages.
+	 */
+	if (!new_event && keycode != KEY_RESERVED &&
+	    dev->allowed_protocols == RC_PROTO_BIT_CEC &&
+	    !timer_pending(&dev->timer_repeat) &&
+	    dev->input_dev->rep[REP_PERIOD] &&
+	    !dev->input_dev->rep[REP_DELAY]) {
+		input_event(dev->input_dev, EV_KEY, keycode, 2);
+		mod_timer(&dev->timer_repeat, jiffies +
+			  msecs_to_jiffies(dev->input_dev->rep[REP_PERIOD]));
+	}
+
+	input_sync(dev->input_dev);
+}
+
+/**
+ * rc_keydown() - generates input event for a key press
+ * @dev:	the struct rc_dev descriptor of the device
+ * @protocol:	the protocol for the keypress
+ * @scancode:	the scancode for the keypress
+ * @toggle:     the toggle value (protocol dependent, if the protocol doesn't
+ *              support toggle values, this should be set to zero)
+ *
+ * This routine is used to signal that a key has been pressed on the
+ * remote control.
+ */
+void rc_keydown(struct rc_dev *dev, enum rc_proto protocol, u64 scancode,
+		u8 toggle)
+{
+	unsigned long flags;
+	u32 keycode = rc_g_keycode_from_table(dev, scancode);
+
+	spin_lock_irqsave(&dev->keylock, flags);
+	ir_do_keydown(dev, protocol, scancode, keycode, toggle);
+
+	if (dev->keypressed) {
+		dev->keyup_jiffies = jiffies + usecs_to_jiffies(dev->timeout) +
+			msecs_to_jiffies(repeat_period(protocol));
+		mod_timer(&dev->timer_keyup, dev->keyup_jiffies);
+	}
+	spin_unlock_irqrestore(&dev->keylock, flags);
+}
+EXPORT_SYMBOL_GPL(rc_keydown);
+
+/**
+ * rc_keydown_notimeout() - generates input event for a key press without
+ *                          an automatic keyup event at a later time
+ * @dev:	the struct rc_dev descriptor of the device
+ * @protocol:	the protocol for the keypress
+ * @scancode:	the scancode for the keypress
+ * @toggle:     the toggle value (protocol dependent, if the protocol doesn't
+ *              support toggle values, this should be set to zero)
+ *
+ * This routine is used to signal that a key has been pressed on the
+ * remote control. The driver must manually call rc_keyup() at a later stage.
+ */
+void rc_keydown_notimeout(struct rc_dev *dev, enum rc_proto protocol,
+			  u64 scancode, u8 toggle)
+{
+	unsigned long flags;
+	u32 keycode = rc_g_keycode_from_table(dev, scancode);
+
+	spin_lock_irqsave(&dev->keylock, flags);
+	ir_do_keydown(dev, protocol, scancode, keycode, toggle);
+	spin_unlock_irqrestore(&dev->keylock, flags);
+}
+EXPORT_SYMBOL_GPL(rc_keydown_notimeout);
+
+/**
+ * rc_validate_scancode() - checks that a scancode is valid for a protocol.
+ *	For nec, it should do the opposite of ir_nec_bytes_to_scancode()
+ * @proto:	protocol
+ * @scancode:	scancode
+ */
+bool rc_validate_scancode(enum rc_proto proto, u32 scancode)
+{
+	switch (proto) {
+	/*
+	 * NECX has a 16-bit address; if the lower 8 bits match the upper
+	 * 8 bits inverted, then the address would match regular nec.
+	 */
+	case RC_PROTO_NECX:
+		if ((((scancode >> 16) ^ ~(scancode >> 8)) & 0xff) == 0)
+			return false;
+		break;
+	/*
+	 * NEC32 has a 16 bit address and 16 bit command. If the lower 8 bits
+	 * of the command match the upper 8 bits inverted, then it would
+	 * be either NEC or NECX.
+	 */
+	case RC_PROTO_NEC32:
+		if ((((scancode >> 8) ^ ~scancode) & 0xff) == 0)
+			return false;
+		break;
+	/*
+	 * If the customer code (top 32-bit) is 0x800f, it is MCE else it
+	 * is regular mode-6a 32 bit
+	 */
+	case RC_PROTO_RC6_MCE:
+		if ((scancode & 0xffff0000) != 0x800f0000)
+			return false;
+		break;
+	case RC_PROTO_RC6_6A_32:
+		if ((scancode & 0xffff0000) == 0x800f0000)
+			return false;
+		break;
+	default:
+		break;
+	}
+
+	return true;
+}
+
+/**
+ * rc_validate_filter() - checks that the scancode and mask are valid and
+ *			  provides sensible defaults
+ * @dev:	the struct rc_dev descriptor of the device
+ * @filter:	the scancode and mask
+ *
+ * return:	0 or -EINVAL if the filter is not valid
+ */
+static int rc_validate_filter(struct rc_dev *dev,
+			      struct rc_scancode_filter *filter)
+{
+	u32 mask, s = filter->data;
+	enum rc_proto protocol = dev->wakeup_protocol;
+
+	if (protocol >= ARRAY_SIZE(protocols))
+		return -EINVAL;
+
+	mask = protocols[protocol].scancode_bits;
+
+	if (!rc_validate_scancode(protocol, s))
+		return -EINVAL;
+
+	filter->data &= mask;
+	filter->mask &= mask;
+
+	/*
+	 * If we have to raw encode the IR for wakeup, we cannot have a mask
+	 */
+	if (dev->encode_wakeup && filter->mask != 0 && filter->mask != mask)
+		return -EINVAL;
+
+	return 0;
+}
+
+int rc_open(struct rc_dev *rdev)
+{
+	int rval = 0;
+
+	if (!rdev)
+		return -EINVAL;
+
+	mutex_lock(&rdev->lock);
+
+	if (!rdev->registered) {
+		rval = -ENODEV;
+	} else {
+		if (!rdev->users++ && rdev->open)
+			rval = rdev->open(rdev);
+
+		if (rval)
+			rdev->users--;
+	}
+
+	mutex_unlock(&rdev->lock);
+
+	return rval;
+}
+
+static int ir_open(struct input_dev *idev)
+{
+	struct rc_dev *rdev = input_get_drvdata(idev);
+
+	return rc_open(rdev);
+}
+
+void rc_close(struct rc_dev *rdev)
+{
+	if (rdev) {
+		mutex_lock(&rdev->lock);
+
+		if (!--rdev->users && rdev->close && rdev->registered)
+			rdev->close(rdev);
+
+		mutex_unlock(&rdev->lock);
+	}
+}
+
+static void ir_close(struct input_dev *idev)
+{
+	struct rc_dev *rdev = input_get_drvdata(idev);
+	rc_close(rdev);
+}
+
+/* class for /sys/class/rc */
+static char *rc_devnode(const struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "rc/%s", dev_name(dev));
+}
+
+static struct class rc_class = {
+	.name		= "rc",
+	.devnode	= rc_devnode,
+};
+
+/*
+ * These are the protocol textual descriptions that are
+ * used by the sysfs protocols file. Note that the order
+ * of the entries is relevant.
+ */
+static const struct {
+	u64	type;
+	const char	*name;
+	const char	*module_name;
+} proto_names[] = {
+	{ RC_PROTO_BIT_NONE,	"none",		NULL			},
+	{ RC_PROTO_BIT_OTHER,	"other",	NULL			},
+	{ RC_PROTO_BIT_UNKNOWN,	"unknown",	NULL			},
+	{ RC_PROTO_BIT_RC5 |
+	  RC_PROTO_BIT_RC5X_20,	"rc-5",		"ir-rc5-decoder"	},
+	{ RC_PROTO_BIT_NEC |
+	  RC_PROTO_BIT_NECX |
+	  RC_PROTO_BIT_NEC32,	"nec",		"ir-nec-decoder"	},
+	{ RC_PROTO_BIT_RC6_0 |
+	  RC_PROTO_BIT_RC6_6A_20 |
+	  RC_PROTO_BIT_RC6_6A_24 |
+	  RC_PROTO_BIT_RC6_6A_32 |
+	  RC_PROTO_BIT_RC6_MCE,	"rc-6",		"ir-rc6-decoder"	},
+	{ RC_PROTO_BIT_JVC,	"jvc",		"ir-jvc-decoder"	},
+	{ RC_PROTO_BIT_SONY12 |
+	  RC_PROTO_BIT_SONY15 |
+	  RC_PROTO_BIT_SONY20,	"sony",		"ir-sony-decoder"	},
+	{ RC_PROTO_BIT_RC5_SZ,	"rc-5-sz",	"ir-rc5-decoder"	},
+	{ RC_PROTO_BIT_SANYO,	"sanyo",	"ir-sanyo-decoder"	},
+	{ RC_PROTO_BIT_SHARP,	"sharp",	"ir-sharp-decoder"	},
+	{ RC_PROTO_BIT_MCIR2_KBD |
+	  RC_PROTO_BIT_MCIR2_MSE, "mce_kbd",	"ir-mce_kbd-decoder"	},
+	{ RC_PROTO_BIT_XMP,	"xmp",		"ir-xmp-decoder"	},
+	{ RC_PROTO_BIT_CEC,	"cec",		NULL			},
+	{ RC_PROTO_BIT_IMON,	"imon",		"ir-imon-decoder"	},
+	{ RC_PROTO_BIT_RCMM12 |
+	  RC_PROTO_BIT_RCMM24 |
+	  RC_PROTO_BIT_RCMM32,	"rc-mm",	"ir-rcmm-decoder"	},
+	{ RC_PROTO_BIT_XBOX_DVD, "xbox-dvd",	NULL			},
+};
+
+/**
+ * struct rc_filter_attribute - Device attribute relating to a filter type.
+ * @attr:	Device attribute.
+ * @type:	Filter type.
+ * @mask:	false for filter value, true for filter mask.
+ */
+struct rc_filter_attribute {
+	struct device_attribute		attr;
+	enum rc_filter_type		type;
+	bool				mask;
+};
+#define to_rc_filter_attr(a) container_of(a, struct rc_filter_attribute, attr)
+
+#define RC_FILTER_ATTR(_name, _mode, _show, _store, _type, _mask)	\
+	struct rc_filter_attribute dev_attr_##_name = {			\
+		.attr = __ATTR(_name, _mode, _show, _store),		\
+		.type = (_type),					\
+		.mask = (_mask),					\
+	}
+
+/**
+ * show_protocols() - shows the current IR protocol(s)
+ * @device:	the device descriptor
+ * @mattr:	the device attribute struct
+ * @buf:	a pointer to the output buffer
+ *
+ * This routine is a callback routine for input read the IR protocol type(s).
+ * it is triggered by reading /sys/class/rc/rc?/protocols.
+ * It returns the protocol names of supported protocols.
+ * Enabled protocols are printed in brackets.
+ *
+ * dev->lock is taken to guard against races between
+ * store_protocols and show_protocols.
+ */
+static ssize_t show_protocols(struct device *device,
+			      struct device_attribute *mattr, char *buf)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+	u64 allowed, enabled;
+	char *tmp = buf;
+	int i;
+
+	mutex_lock(&dev->lock);
+
+	enabled = dev->enabled_protocols;
+	allowed = dev->allowed_protocols;
+	if (dev->raw && !allowed)
+		allowed = ir_raw_get_allowed_protocols();
+
+	mutex_unlock(&dev->lock);
+
+	dev_dbg(&dev->dev, "%s: allowed - 0x%llx, enabled - 0x%llx\n",
+		__func__, (long long)allowed, (long long)enabled);
+
+	for (i = 0; i < ARRAY_SIZE(proto_names); i++) {
+		if (allowed & enabled & proto_names[i].type)
+			tmp += sprintf(tmp, "[%s] ", proto_names[i].name);
+		else if (allowed & proto_names[i].type)
+			tmp += sprintf(tmp, "%s ", proto_names[i].name);
+
+		if (allowed & proto_names[i].type)
+			allowed &= ~proto_names[i].type;
+	}
+
+#ifdef CONFIG_LIRC
+	if (dev->driver_type == RC_DRIVER_IR_RAW)
+		tmp += sprintf(tmp, "[lirc] ");
+#endif
+
+	if (tmp != buf)
+		tmp--;
+	*tmp = '\n';
+
+	return tmp + 1 - buf;
+}
+
+/**
+ * parse_protocol_change() - parses a protocol change request
+ * @dev:	rc_dev device
+ * @protocols:	pointer to the bitmask of current protocols
+ * @buf:	pointer to the buffer with a list of changes
+ *
+ * Writing "+proto" will add a protocol to the protocol mask.
+ * Writing "-proto" will remove a protocol from protocol mask.
+ * Writing "proto" will enable only "proto".
+ * Writing "none" will disable all protocols.
+ * Returns the number of changes performed or a negative error code.
+ */
+static int parse_protocol_change(struct rc_dev *dev, u64 *protocols,
+				 const char *buf)
+{
+	const char *tmp;
+	unsigned count = 0;
+	bool enable, disable;
+	u64 mask;
+	int i;
+
+	while ((tmp = strsep((char **)&buf, " \n")) != NULL) {
+		if (!*tmp)
+			break;
+
+		if (*tmp == '+') {
+			enable = true;
+			disable = false;
+			tmp++;
+		} else if (*tmp == '-') {
+			enable = false;
+			disable = true;
+			tmp++;
+		} else {
+			enable = false;
+			disable = false;
+		}
+
+		for (i = 0; i < ARRAY_SIZE(proto_names); i++) {
+			if (!strcasecmp(tmp, proto_names[i].name)) {
+				mask = proto_names[i].type;
+				break;
+			}
+		}
+
+		if (i == ARRAY_SIZE(proto_names)) {
+			if (!strcasecmp(tmp, "lirc"))
+				mask = 0;
+			else {
+				dev_dbg(&dev->dev, "Unknown protocol: '%s'\n",
+					tmp);
+				return -EINVAL;
+			}
+		}
+
+		count++;
+
+		if (enable)
+			*protocols |= mask;
+		else if (disable)
+			*protocols &= ~mask;
+		else
+			*protocols = mask;
+	}
+
+	if (!count) {
+		dev_dbg(&dev->dev, "Protocol not specified\n");
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+void ir_raw_load_modules(u64 *protocols)
+{
+	u64 available;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(proto_names); i++) {
+		if (proto_names[i].type == RC_PROTO_BIT_NONE ||
+		    proto_names[i].type & (RC_PROTO_BIT_OTHER |
+					   RC_PROTO_BIT_UNKNOWN))
+			continue;
+
+		available = ir_raw_get_allowed_protocols();
+		if (!(*protocols & proto_names[i].type & ~available))
+			continue;
+
+		if (!proto_names[i].module_name) {
+			pr_err("Can't enable IR protocol %s\n",
+			       proto_names[i].name);
+			*protocols &= ~proto_names[i].type;
+			continue;
+		}
+
+		ret = request_module("%s", proto_names[i].module_name);
+		if (ret < 0) {
+			pr_err("Couldn't load IR protocol module %s\n",
+			       proto_names[i].module_name);
+			*protocols &= ~proto_names[i].type;
+			continue;
+		}
+		msleep(20);
+		available = ir_raw_get_allowed_protocols();
+		if (!(*protocols & proto_names[i].type & ~available))
+			continue;
+
+		pr_err("Loaded IR protocol module %s, but protocol %s still not available\n",
+		       proto_names[i].module_name,
+		       proto_names[i].name);
+		*protocols &= ~proto_names[i].type;
+	}
+}
+
+/**
+ * store_protocols() - changes the current/wakeup IR protocol(s)
+ * @device:	the device descriptor
+ * @mattr:	the device attribute struct
+ * @buf:	a pointer to the input buffer
+ * @len:	length of the input buffer
+ *
+ * This routine is for changing the IR protocol type.
+ * It is triggered by writing to /sys/class/rc/rc?/[wakeup_]protocols.
+ * See parse_protocol_change() for the valid commands.
+ * Returns @len on success or a negative error code.
+ *
+ * dev->lock is taken to guard against races between
+ * store_protocols and show_protocols.
+ */
+static ssize_t store_protocols(struct device *device,
+			       struct device_attribute *mattr,
+			       const char *buf, size_t len)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+	u64 *current_protocols;
+	struct rc_scancode_filter *filter;
+	u64 old_protocols, new_protocols;
+	ssize_t rc;
+
+	dev_dbg(&dev->dev, "Normal protocol change requested\n");
+	current_protocols = &dev->enabled_protocols;
+	filter = &dev->scancode_filter;
+
+	if (!dev->change_protocol) {
+		dev_dbg(&dev->dev, "Protocol switching not supported\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&dev->lock);
+	if (!dev->registered) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
+
+	old_protocols = *current_protocols;
+	new_protocols = old_protocols;
+	rc = parse_protocol_change(dev, &new_protocols, buf);
+	if (rc < 0)
+		goto out;
+
+	if (dev->driver_type == RC_DRIVER_IR_RAW)
+		ir_raw_load_modules(&new_protocols);
+
+	rc = dev->change_protocol(dev, &new_protocols);
+	if (rc < 0) {
+		dev_dbg(&dev->dev, "Error setting protocols to 0x%llx\n",
+			(long long)new_protocols);
+		goto out;
+	}
+
+	if (new_protocols != old_protocols) {
+		*current_protocols = new_protocols;
+		dev_dbg(&dev->dev, "Protocols changed to 0x%llx\n",
+			(long long)new_protocols);
+	}
+
+	/*
+	 * If a protocol change was attempted the filter may need updating, even
+	 * if the actual protocol mask hasn't changed (since the driver may have
+	 * cleared the filter).
+	 * Try setting the same filter with the new protocol (if any).
+	 * Fall back to clearing the filter.
+	 */
+	if (dev->s_filter && filter->mask) {
+		if (new_protocols)
+			rc = dev->s_filter(dev, filter);
+		else
+			rc = -1;
+
+		if (rc < 0) {
+			filter->data = 0;
+			filter->mask = 0;
+			dev->s_filter(dev, filter);
+		}
+	}
+
+	rc = len;
+
+out:
+	mutex_unlock(&dev->lock);
+	return rc;
+}
+
+/**
+ * show_filter() - shows the current scancode filter value or mask
+ * @device:	the device descriptor
+ * @attr:	the device attribute struct
+ * @buf:	a pointer to the output buffer
+ *
+ * This routine is a callback routine to read a scancode filter value or mask.
+ * It is triggered by reading /sys/class/rc/rc?/[wakeup_]filter[_mask].
+ * It prints the current scancode filter value or mask of the appropriate filter
+ * type in hexadecimal into @buf and returns the size of the buffer.
+ *
+ * Bits of the filter value corresponding to set bits in the filter mask are
+ * compared against input scancodes and non-matching scancodes are discarded.
+ *
+ * dev->lock is taken to guard against races between
+ * store_filter and show_filter.
+ */
+static ssize_t show_filter(struct device *device,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+	struct rc_filter_attribute *fattr = to_rc_filter_attr(attr);
+	struct rc_scancode_filter *filter;
+	u32 val;
+
+	mutex_lock(&dev->lock);
+
+	if (fattr->type == RC_FILTER_NORMAL)
+		filter = &dev->scancode_filter;
+	else
+		filter = &dev->scancode_wakeup_filter;
+
+	if (fattr->mask)
+		val = filter->mask;
+	else
+		val = filter->data;
+	mutex_unlock(&dev->lock);
+
+	return sprintf(buf, "%#x\n", val);
+}
+
+/**
+ * store_filter() - changes the scancode filter value
+ * @device:	the device descriptor
+ * @attr:	the device attribute struct
+ * @buf:	a pointer to the input buffer
+ * @len:	length of the input buffer
+ *
+ * This routine is for changing a scancode filter value or mask.
+ * It is triggered by writing to /sys/class/rc/rc?/[wakeup_]filter[_mask].
+ * Returns -EINVAL if an invalid filter value for the current protocol was
+ * specified or if scancode filtering is not supported by the driver, otherwise
+ * returns @len.
+ *
+ * Bits of the filter value corresponding to set bits in the filter mask are
+ * compared against input scancodes and non-matching scancodes are discarded.
+ *
+ * dev->lock is taken to guard against races between
+ * store_filter and show_filter.
+ */
+static ssize_t store_filter(struct device *device,
+			    struct device_attribute *attr,
+			    const char *buf, size_t len)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+	struct rc_filter_attribute *fattr = to_rc_filter_attr(attr);
+	struct rc_scancode_filter new_filter, *filter;
+	int ret;
+	unsigned long val;
+	int (*set_filter)(struct rc_dev *dev, struct rc_scancode_filter *filter);
+
+	ret = kstrtoul(buf, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	if (fattr->type == RC_FILTER_NORMAL) {
+		set_filter = dev->s_filter;
+		filter = &dev->scancode_filter;
+	} else {
+		set_filter = dev->s_wakeup_filter;
+		filter = &dev->scancode_wakeup_filter;
+	}
+
+	if (!set_filter)
+		return -EINVAL;
+
+	mutex_lock(&dev->lock);
+	if (!dev->registered) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
+
+	new_filter = *filter;
+	if (fattr->mask)
+		new_filter.mask = val;
+	else
+		new_filter.data = val;
+
+	if (fattr->type == RC_FILTER_WAKEUP) {
+		/*
+		 * Refuse to set a filter unless a protocol is enabled
+		 * and the filter is valid for that protocol
+		 */
+		if (dev->wakeup_protocol != RC_PROTO_UNKNOWN)
+			ret = rc_validate_filter(dev, &new_filter);
+		else
+			ret = -EINVAL;
+
+		if (ret != 0)
+			goto unlock;
+	}
+
+	if (fattr->type == RC_FILTER_NORMAL && !dev->enabled_protocols &&
+	    val) {
+		/* refuse to set a filter unless a protocol is enabled */
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	ret = set_filter(dev, &new_filter);
+	if (ret < 0)
+		goto unlock;
+
+	*filter = new_filter;
+
+unlock:
+	mutex_unlock(&dev->lock);
+	return (ret < 0) ? ret : len;
+}
+
+/**
+ * show_wakeup_protocols() - shows the wakeup IR protocol
+ * @device:	the device descriptor
+ * @mattr:	the device attribute struct
+ * @buf:	a pointer to the output buffer
+ *
+ * This routine is a callback routine for input read the IR protocol type(s).
+ * it is triggered by reading /sys/class/rc/rc?/wakeup_protocols.
+ * It returns the protocol names of supported protocols.
+ * The enabled protocols are printed in brackets.
+ *
+ * dev->lock is taken to guard against races between
+ * store_wakeup_protocols and show_wakeup_protocols.
+ */
+static ssize_t show_wakeup_protocols(struct device *device,
+				     struct device_attribute *mattr,
+				     char *buf)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+	u64 allowed;
+	enum rc_proto enabled;
+	char *tmp = buf;
+	int i;
+
+	mutex_lock(&dev->lock);
+
+	allowed = dev->allowed_wakeup_protocols;
+	enabled = dev->wakeup_protocol;
+
+	mutex_unlock(&dev->lock);
+
+	dev_dbg(&dev->dev, "%s: allowed - 0x%llx, enabled - %d\n",
+		__func__, (long long)allowed, enabled);
+
+	for (i = 0; i < ARRAY_SIZE(protocols); i++) {
+		if (allowed & (1ULL << i)) {
+			if (i == enabled)
+				tmp += sprintf(tmp, "[%s] ", protocols[i].name);
+			else
+				tmp += sprintf(tmp, "%s ", protocols[i].name);
+		}
+	}
+
+	if (tmp != buf)
+		tmp--;
+	*tmp = '\n';
+
+	return tmp + 1 - buf;
+}
+
+/**
+ * store_wakeup_protocols() - changes the wakeup IR protocol(s)
+ * @device:	the device descriptor
+ * @mattr:	the device attribute struct
+ * @buf:	a pointer to the input buffer
+ * @len:	length of the input buffer
+ *
+ * This routine is for changing the IR protocol type.
+ * It is triggered by writing to /sys/class/rc/rc?/wakeup_protocols.
+ * Returns @len on success or a negative error code.
+ *
+ * dev->lock is taken to guard against races between
+ * store_wakeup_protocols and show_wakeup_protocols.
+ */
+static ssize_t store_wakeup_protocols(struct device *device,
+				      struct device_attribute *mattr,
+				      const char *buf, size_t len)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+	enum rc_proto protocol = RC_PROTO_UNKNOWN;
+	ssize_t rc;
+	u64 allowed;
+	int i;
+
+	mutex_lock(&dev->lock);
+	if (!dev->registered) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
+
+	allowed = dev->allowed_wakeup_protocols;
+
+	if (!sysfs_streq(buf, "none")) {
+		for (i = 0; i < ARRAY_SIZE(protocols); i++) {
+			if ((allowed & (1ULL << i)) &&
+			    sysfs_streq(buf, protocols[i].name)) {
+				protocol = i;
+				break;
+			}
+		}
+
+		if (i == ARRAY_SIZE(protocols)) {
+			rc = -EINVAL;
+			goto out;
+		}
+
+		if (dev->encode_wakeup) {
+			u64 mask = 1ULL << protocol;
+
+			ir_raw_load_modules(&mask);
+			if (!mask) {
+				rc = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	if (dev->wakeup_protocol != protocol) {
+		dev->wakeup_protocol = protocol;
+		dev_dbg(&dev->dev, "Wakeup protocol changed to %d\n", protocol);
+
+		if (protocol == RC_PROTO_RC6_MCE)
+			dev->scancode_wakeup_filter.data = 0x800f0000;
+		else
+			dev->scancode_wakeup_filter.data = 0;
+		dev->scancode_wakeup_filter.mask = 0;
+
+		rc = dev->s_wakeup_filter(dev, &dev->scancode_wakeup_filter);
+		if (rc == 0)
+			rc = len;
+	} else {
+		rc = len;
+	}
+
+out:
+	mutex_unlock(&dev->lock);
+	return rc;
+}
+
+static void rc_dev_release(struct device *device)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+
+	kfree(dev);
+}
+
+static int rc_dev_uevent(const struct device *device, struct kobj_uevent_env *env)
+{
+	struct rc_dev *dev = to_rc_dev(device);
+	int ret = 0;
+
+	mutex_lock(&dev->lock);
+
+	if (!dev->registered)
+		ret = -ENODEV;
+	if (ret == 0 && dev->rc_map.name)
+		ret = add_uevent_var(env, "NAME=%s", dev->rc_map.name);
+	if (ret == 0 && dev->driver_name)
+		ret = add_uevent_var(env, "DRV_NAME=%s", dev->driver_name);
+	if (ret == 0 && dev->device_name)
+		ret = add_uevent_var(env, "DEV_NAME=%s", dev->device_name);
+
+	mutex_unlock(&dev->lock);
+
+	return ret;
+}
+
+/*
+ * Static device attribute struct with the sysfs attributes for IR's
+ */
+static struct device_attribute dev_attr_ro_protocols =
+__ATTR(protocols, 0444, show_protocols, NULL);
+static struct device_attribute dev_attr_rw_protocols =
+__ATTR(protocols, 0644, show_protocols, store_protocols);
+static DEVICE_ATTR(wakeup_protocols, 0644, show_wakeup_protocols,
+		   store_wakeup_protocols);
+static RC_FILTER_ATTR(filter, S_IRUGO|S_IWUSR,
+		      show_filter, store_filter, RC_FILTER_NORMAL, false);
+static RC_FILTER_ATTR(filter_mask, S_IRUGO|S_IWUSR,
+		      show_filter, store_filter, RC_FILTER_NORMAL, true);
+static RC_FILTER_ATTR(wakeup_filter, S_IRUGO|S_IWUSR,
+		      show_filter, store_filter, RC_FILTER_WAKEUP, false);
+static RC_FILTER_ATTR(wakeup_filter_mask, S_IRUGO|S_IWUSR,
+		      show_filter, store_filter, RC_FILTER_WAKEUP, true);
+
+static struct attribute *rc_dev_rw_protocol_attrs[] = {
+	&dev_attr_rw_protocols.attr,
+	NULL,
+};
+
+static const struct attribute_group rc_dev_rw_protocol_attr_grp = {
+	.attrs	= rc_dev_rw_protocol_attrs,
+};
+
+static struct attribute *rc_dev_ro_protocol_attrs[] = {
+	&dev_attr_ro_protocols.attr,
+	NULL,
+};
+
+static const struct attribute_group rc_dev_ro_protocol_attr_grp = {
+	.attrs	= rc_dev_ro_protocol_attrs,
+};
+
+static struct attribute *rc_dev_filter_attrs[] = {
+	&dev_attr_filter.attr.attr,
+	&dev_attr_filter_mask.attr.attr,
+	NULL,
+};
+
+static const struct attribute_group rc_dev_filter_attr_grp = {
+	.attrs	= rc_dev_filter_attrs,
+};
+
+static struct attribute *rc_dev_wakeup_filter_attrs[] = {
+	&dev_attr_wakeup_filter.attr.attr,
+	&dev_attr_wakeup_filter_mask.attr.attr,
+	&dev_attr_wakeup_protocols.attr,
+	NULL,
+};
+
+static const struct attribute_group rc_dev_wakeup_filter_attr_grp = {
+	.attrs	= rc_dev_wakeup_filter_attrs,
+};
+
+static const struct device_type rc_dev_type = {
+	.release	= rc_dev_release,
+	.uevent		= rc_dev_uevent,
+};
+
+struct rc_dev *rc_allocate_device(enum rc_driver_type type)
+{
+	struct rc_dev *dev;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	if (type != RC_DRIVER_IR_RAW_TX) {
+		dev->input_dev = input_allocate_device();
+		if (!dev->input_dev) {
+			kfree(dev);
+			return NULL;
+		}
+
+		dev->input_dev->getkeycode = ir_getkeycode;
+		dev->input_dev->setkeycode = ir_setkeycode;
+		input_set_drvdata(dev->input_dev, dev);
+
+		dev->timeout = IR_DEFAULT_TIMEOUT;
+		timer_setup(&dev->timer_keyup, ir_timer_keyup, 0);
+		timer_setup(&dev->timer_repeat, ir_timer_repeat, 0);
+
+		spin_lock_init(&dev->rc_map.lock);
+		spin_lock_init(&dev->keylock);
+	}
+	mutex_init(&dev->lock);
+
+	dev->dev.type = &rc_dev_type;
+	dev->dev.class = &rc_class;
+	device_initialize(&dev->dev);
+
+	dev->driver_type = type;
+
+	__module_get(THIS_MODULE);
+	return dev;
+}
+EXPORT_SYMBOL_GPL(rc_allocate_device);
+
+void rc_free_device(struct rc_dev *dev)
+{
+	if (!dev)
+		return;
+
+	input_free_device(dev->input_dev);
+
+	put_device(&dev->dev);
+
+	/* kfree(dev) will be called by the callback function
+	   rc_dev_release() */
+
+	module_put(THIS_MODULE);
+}
+EXPORT_SYMBOL_GPL(rc_free_device);
+
+static void devm_rc_alloc_release(struct device *dev, void *res)
+{
+	rc_free_device(*(struct rc_dev **)res);
+}
+
+struct rc_dev *devm_rc_allocate_device(struct device *dev,
+				       enum rc_driver_type type)
+{
+	struct rc_dev **dr, *rc;
+
+	dr = devres_alloc(devm_rc_alloc_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return NULL;
+
+	rc = rc_allocate_device(type);
+	if (!rc) {
+		devres_free(dr);
+		return NULL;
+	}
+
+	rc->dev.parent = dev;
+	rc->managed_alloc = true;
+	*dr = rc;
+	devres_add(dev, dr);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(devm_rc_allocate_device);
+
+static int rc_prepare_rx_device(struct rc_dev *dev)
+{
+	int rc;
+	struct rc_map *rc_map;
+	u64 rc_proto;
+
+	if (!dev->map_name)
+		return -EINVAL;
+
+	rc_map = rc_map_get(dev->map_name);
+	if (!rc_map)
+		rc_map = rc_map_get(RC_MAP_EMPTY);
+	if (!rc_map || !rc_map->scan || rc_map->size == 0)
+		return -EINVAL;
+
+	rc = ir_setkeytable(dev, rc_map);
+	if (rc)
+		return rc;
+
+	rc_proto = BIT_ULL(rc_map->rc_proto);
+
+	if (dev->driver_type == RC_DRIVER_SCANCODE && !dev->change_protocol)
+		dev->enabled_protocols = dev->allowed_protocols;
+
+	if (dev->driver_type == RC_DRIVER_IR_RAW)
+		ir_raw_load_modules(&rc_proto);
+
+	if (dev->change_protocol) {
+		rc = dev->change_protocol(dev, &rc_proto);
+		if (rc < 0)
+			goto out_table;
+		dev->enabled_protocols = rc_proto;
+	}
+
+	/* Keyboard events */
+	set_bit(EV_KEY, dev->input_dev->evbit);
+	set_bit(EV_REP, dev->input_dev->evbit);
+	set_bit(EV_MSC, dev->input_dev->evbit);
+	set_bit(MSC_SCAN, dev->input_dev->mscbit);
+
+	/* Pointer/mouse events */
+	set_bit(INPUT_PROP_POINTING_STICK, dev->input_dev->propbit);
+	set_bit(EV_REL, dev->input_dev->evbit);
+	set_bit(REL_X, dev->input_dev->relbit);
+	set_bit(REL_Y, dev->input_dev->relbit);
+
+	if (dev->open)
+		dev->input_dev->open = ir_open;
+	if (dev->close)
+		dev->input_dev->close = ir_close;
+
+	dev->input_dev->dev.parent = &dev->dev;
+	memcpy(&dev->input_dev->id, &dev->input_id, sizeof(dev->input_id));
+	dev->input_dev->phys = dev->input_phys;
+	dev->input_dev->name = dev->device_name;
+
+	return 0;
+
+out_table:
+	ir_free_table(&dev->rc_map);
+
+	return rc;
+}
+
+static int rc_setup_rx_device(struct rc_dev *dev)
+{
+	int rc;
+
+	/* rc_open will be called here */
+	rc = input_register_device(dev->input_dev);
+	if (rc)
+		return rc;
+
+	/*
+	 * Default delay of 250ms is too short for some protocols, especially
+	 * since the timeout is currently set to 250ms. Increase it to 500ms,
+	 * to avoid wrong repetition of the keycodes. Note that this must be
+	 * set after the call to input_register_device().
+	 */
+	if (dev->allowed_protocols == RC_PROTO_BIT_CEC)
+		dev->input_dev->rep[REP_DELAY] = 0;
+	else
+		dev->input_dev->rep[REP_DELAY] = 500;
+
+	/*
+	 * As a repeat event on protocols like RC-5 and NEC take as long as
+	 * 110/114ms, using 33ms as a repeat period is not the right thing
+	 * to do.
+	 */
+	dev->input_dev->rep[REP_PERIOD] = 125;
+
+	return 0;
+}
+
+static void rc_free_rx_device(struct rc_dev *dev)
+{
+	if (!dev)
+		return;
+
+	if (dev->input_dev) {
+		input_unregister_device(dev->input_dev);
+		dev->input_dev = NULL;
+	}
+
+	ir_free_table(&dev->rc_map);
+}
+
+int rc_register_device(struct rc_dev *dev)
+{
+	const char *path;
+	int attr = 0;
+	int minor;
+	int rc;
+
+	if (!dev)
+		return -EINVAL;
+
+	minor = ida_alloc_max(&rc_ida, RC_DEV_MAX - 1, GFP_KERNEL);
+	if (minor < 0)
+		return minor;
+
+	dev->minor = minor;
+	dev_set_name(&dev->dev, "rc%u", dev->minor);
+	dev_set_drvdata(&dev->dev, dev);
+
+	dev->dev.groups = dev->sysfs_groups;
+	if (dev->driver_type == RC_DRIVER_SCANCODE && !dev->change_protocol)
+		dev->sysfs_groups[attr++] = &rc_dev_ro_protocol_attr_grp;
+	else if (dev->driver_type != RC_DRIVER_IR_RAW_TX)
+		dev->sysfs_groups[attr++] = &rc_dev_rw_protocol_attr_grp;
+	if (dev->s_filter)
+		dev->sysfs_groups[attr++] = &rc_dev_filter_attr_grp;
+	if (dev->s_wakeup_filter)
+		dev->sysfs_groups[attr++] = &rc_dev_wakeup_filter_attr_grp;
+	dev->sysfs_groups[attr++] = NULL;
+
+	if (dev->driver_type == RC_DRIVER_IR_RAW) {
+		rc = ir_raw_event_prepare(dev);
+		if (rc < 0)
+			goto out_minor;
+	}
+
+	if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
+		rc = rc_prepare_rx_device(dev);
+		if (rc)
+			goto out_raw;
+	}
+
+	dev->registered = true;
+
+	rc = device_add(&dev->dev);
+	if (rc)
+		goto out_rx_free;
+
+	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
+	dev_info(&dev->dev, "%s as %s\n",
+		 dev->device_name ?: "Unspecified device", path ?: "N/A");
+	kfree(path);
+
+	/*
+	 * once the input device is registered in rc_setup_rx_device,
+	 * userspace can open the input device and rc_open() will be called
+	 * as a result. This results in driver code being allowed to submit
+	 * keycodes with rc_keydown, so lirc must be registered first.
+	 */
+	if (dev->allowed_protocols != RC_PROTO_BIT_CEC) {
+		rc = lirc_register(dev);
+		if (rc < 0)
+			goto out_dev;
+	}
+
+	if (dev->driver_type != RC_DRIVER_IR_RAW_TX) {
+		rc = rc_setup_rx_device(dev);
+		if (rc)
+			goto out_lirc;
+	}
+
+	if (dev->driver_type == RC_DRIVER_IR_RAW) {
+		rc = ir_raw_event_register(dev);
+		if (rc < 0)
+			goto out_rx;
+	}
+
+	dev_dbg(&dev->dev, "Registered rc%u (driver: %s)\n", dev->minor,
+		dev->driver_name ? dev->driver_name : "unknown");
+
+	return 0;
+
+out_rx:
+	rc_free_rx_device(dev);
+out_lirc:
+	if (dev->allowed_protocols != RC_PROTO_BIT_CEC)
+		lirc_unregister(dev);
+out_dev:
+	device_del(&dev->dev);
+out_rx_free:
+	ir_free_table(&dev->rc_map);
+out_raw:
+	ir_raw_event_free(dev);
+out_minor:
+	ida_free(&rc_ida, minor);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(rc_register_device);
+
+static void devm_rc_release(struct device *dev, void *res)
+{
+	rc_unregister_device(*(struct rc_dev **)res);
+}
+
+int devm_rc_register_device(struct device *parent, struct rc_dev *dev)
+{
+	struct rc_dev **dr;
+	int ret;
+
+	dr = devres_alloc(devm_rc_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = rc_register_device(dev);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	*dr = dev;
+	devres_add(parent, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_rc_register_device);
+
+void rc_unregister_device(struct rc_dev *dev)
+{
+	if (!dev)
+		return;
+
+	if (dev->driver_type == RC_DRIVER_IR_RAW)
+		ir_raw_event_unregister(dev);
+
+	del_timer_sync(&dev->timer_keyup);
+	del_timer_sync(&dev->timer_repeat);
+
+	mutex_lock(&dev->lock);
+	if (dev->users && dev->close)
+		dev->close(dev);
+	dev->registered = false;
+	mutex_unlock(&dev->lock);
+
+	rc_free_rx_device(dev);
+
+	/*
+	 * lirc device should be freed with dev->registered = false, so
+	 * that userspace polling will get notified.
+	 */
+	if (dev->allowed_protocols != RC_PROTO_BIT_CEC)
+		lirc_unregister(dev);
+
+	device_del(&dev->dev);
+
+	ida_free(&rc_ida, dev->minor);
+
+	if (!dev->managed_alloc)
+		rc_free_device(dev);
+}
+
+EXPORT_SYMBOL_GPL(rc_unregister_device);
+
+/*
+ * Init/exit code for the module. Basically, creates/removes /sys/class/rc
+ */
+
+static int __init rc_core_init(void)
+{
+	int rc = class_register(&rc_class);
+	if (rc) {
+		pr_err("rc_core: unable to register rc class\n");
+		return rc;
+	}
+
+	rc = lirc_dev_init();
+	if (rc) {
+		pr_err("rc_core: unable to init lirc\n");
+		class_unregister(&rc_class);
+		return rc;
+	}
+
+	led_trigger_register_simple("rc-feedback", &led_feedback);
+	rc_map_register(&empty_map);
+#ifdef CONFIG_MEDIA_CEC_RC
+	rc_map_register(&cec_map);
+#endif
+
+	return 0;
+}
+
+static void __exit rc_core_exit(void)
+{
+	lirc_dev_exit();
+	class_unregister(&rc_class);
+	led_trigger_unregister_simple(led_feedback);
+#ifdef CONFIG_MEDIA_CEC_RC
+	rc_map_unregister(&cec_map);
+#endif
+	rc_map_unregister(&empty_map);
+}
+
+subsys_initcall(rc_core_init);
+module_exit(rc_core_exit);
+
+MODULE_AUTHOR("Mauro Carvalho Chehab");
+MODULE_LICENSE("GPL v2");