V4L/DVB (13612): IR: Move common IR code to drivers/media/IR

This is the first step of creating a common code for IR that can be
used by other input devices.

For now, keep IR dir at drivers/media, to easy the movement of the IR files,
but later patches may move it to drivers/IR or drivers/input/IR.

No functional changes is done on this patch.

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

1 files changed, 433 insertions, 0 deletions

diff --git a/drivers/media/IR/ir-keytable.c b/drivers/media/IR/ir-keytable.c
new file mode 100644
index 00000000000..99ed2deceef
--- /dev/null
+++ b/drivers/media/IR/ir-keytable.c
@@ -0,0 +1,433 @@
+/* ir-register.c - handle IR scancode->keycode tables
+ *
+ * Copyright (C) 2009 by Mauro Carvalho Chehab <mchehab@redhat.com>
+ */
+
+#include <linux/usb/input.h>
+
+#include <media/ir-common.h>
+
+#define IR_TAB_MIN_SIZE	32
+#define IR_TAB_MAX_SIZE	1024
+
+
+/**
+ * ir_seek_table() - returns the element order on the table
+ * @rc_tab:	the ir_scancode_table with the keymap to be used
+ * @scancode:	the scancode that we're seeking
+ *
+ * This routine is used by the input routines when a key is pressed at the
+ * IR. The scancode is received and needs to be converted into a keycode.
+ * If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the
+ * corresponding keycode from the table.
+ */
+static int ir_seek_table(struct ir_scancode_table *rc_tab, u32 scancode)
+{
+	int rc;
+	unsigned long flags;
+	struct ir_scancode *keymap = rc_tab->scan;
+
+	spin_lock_irqsave(&rc_tab->lock, flags);
+
+	/* FIXME: replace it by a binary search */
+
+	for (rc = 0; rc < rc_tab->size; rc++)
+		if (keymap[rc].scancode == scancode)
+			goto exit;
+
+	/* Not found */
+	rc = -EINVAL;
+
+exit:
+	spin_unlock_irqrestore(&rc_tab->lock, flags);
+	return rc;
+}
+
+/**
+ * ir_roundup_tablesize() - gets an optimum value for the table size
+ * @n_elems:		minimum number of entries to store keycodes
+ *
+ * This routine is used to choose the keycode table size.
+ *
+ * In order to have some empty space for new keycodes,
+ * and knowing in advance that kmalloc allocates only power of two
+ * segments, it optimizes the allocated space to have some spare space
+ * for those new keycodes by using the maximum number of entries that
+ * will be effectively be allocated by kmalloc.
+ * In order to reduce the quantity of table resizes, it has a minimum
+ * table size of IR_TAB_MIN_SIZE.
+ */
+int ir_roundup_tablesize(int n_elems)
+{
+	size_t size;
+
+	if (n_elems < IR_TAB_MIN_SIZE)
+		n_elems = IR_TAB_MIN_SIZE;
+
+	/*
+	 * As kmalloc only allocates sizes of power of two, get as
+	 * much entries as possible for the allocated memory segment
+	 */
+	size = roundup_pow_of_two(n_elems * sizeof(struct ir_scancode));
+	n_elems = size / sizeof(struct ir_scancode);
+
+	return n_elems;
+}
+
+/**
+ * ir_copy_table() - copies a keytable, discarding the unused entries
+ * @destin:	destin table
+ * @origin:	origin table
+ *
+ * Copies all entries where the keycode is not KEY_UNKNOWN/KEY_RESERVED
+ */
+
+int ir_copy_table(struct ir_scancode_table *destin,
+		 const struct ir_scancode_table *origin)
+{
+	int i, j = 0;
+
+	for (i = 0; i < origin->size; i++) {
+		if (origin->scan[i].keycode == KEY_UNKNOWN ||
+		   origin->scan[i].keycode == KEY_RESERVED)
+			continue;
+
+		memcpy(&destin->scan[j], &origin->scan[i], sizeof(struct ir_scancode));
+		j++;
+	}
+	destin->size = j;
+
+	IR_dprintk(1, "Copied %d scancodes to the new keycode table\n", destin->size);
+
+	return 0;
+}
+
+/**
+ * ir_getkeycode() - get a keycode at the evdev scancode ->keycode table
+ * @dev:	the struct input_dev device descriptor
+ * @scancode:	the desired scancode
+ * @keycode:	the keycode to be retorned.
+ *
+ * This routine is used to handle evdev EVIOCGKEY ioctl.
+ * If the key is not found, returns -EINVAL, otherwise, returns 0.
+ */
+static int ir_getkeycode(struct input_dev *dev,
+			 int scancode, int *keycode)
+{
+	int elem;
+	struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
+
+	elem = ir_seek_table(rc_tab, scancode);
+	if (elem >= 0) {
+		*keycode = rc_tab->scan[elem].keycode;
+		return 0;
+	}
+
+	/*
+	 * Scancode not found and table can't be expanded
+	 */
+	if (elem < 0 && rc_tab->size == IR_TAB_MAX_SIZE)
+		return -EINVAL;
+
+	/*
+	 * If is there extra space, returns KEY_RESERVED,
+	 * otherwise, input core won't let ir_setkeycode to work
+	 */
+	*keycode = KEY_RESERVED;
+	return 0;
+}
+
+
+/**
+ * ir_is_resize_needed() - Check if the table needs rezise
+ * @table:		keycode table that may need to resize
+ * @n_elems:		minimum number of entries to store keycodes
+ *
+ * Considering that kmalloc uses power of two storage areas, this
+ * routine detects if the real alloced size will change. If not, it
+ * just returns without doing nothing. Otherwise, it will extend or
+ * reduce the table size to meet the new needs.
+ *
+ * It returns 0 if no resize is needed, 1 otherwise.
+ */
+static int ir_is_resize_needed(struct ir_scancode_table *table, int n_elems)
+{
+	int cur_size = ir_roundup_tablesize(table->size);
+	int new_size = ir_roundup_tablesize(n_elems);
+
+	if (cur_size == new_size)
+		return 0;
+
+	/* Resize is needed */
+	return 1;
+}
+
+/**
+ * ir_delete_key() - remove a keycode from the table
+ * @rc_tab:		keycode table
+ * @elem:		element to be removed
+ *
+ */
+static void ir_delete_key(struct ir_scancode_table *rc_tab, int elem)
+{
+	unsigned long flags = 0;
+	int newsize = rc_tab->size - 1;
+	int resize = ir_is_resize_needed(rc_tab, newsize);
+	struct ir_scancode *oldkeymap = rc_tab->scan;
+	struct ir_scancode *newkeymap;
+
+	if (resize) {
+		newkeymap = kzalloc(ir_roundup_tablesize(newsize) *
+				    sizeof(*newkeymap), GFP_ATOMIC);
+
+		/* There's no memory for resize. Keep the old table */
+		if (!newkeymap)
+			resize = 0;
+	}
+
+	if (!resize) {
+		newkeymap = oldkeymap;
+
+		/* We'll modify the live table. Lock it */
+		spin_lock_irqsave(&rc_tab->lock, flags);
+	}
+
+	/*
+	 * Copy the elements before the one that will be deleted
+	 * if (!resize), both oldkeymap and newkeymap points
+	 * to the same place, so, there's no need to copy
+	 */
+	if (resize && elem > 0)
+		memcpy(newkeymap, oldkeymap,
+		       elem * sizeof(*newkeymap));
+
+	/*
+	 * Copy the other elements overwriting the element to be removed
+	 * This operation applies to both resize and non-resize case
+	 */
+	if (elem < newsize)
+		memcpy(&newkeymap[elem], &oldkeymap[elem + 1],
+		       (newsize - elem) * sizeof(*newkeymap));
+
+	if (resize) {
+		/*
+		 * As the copy happened to a temporary table, only here
+		 * it needs to lock while replacing the table pointers
+		 * to use the new table
+		 */
+		spin_lock_irqsave(&rc_tab->lock, flags);
+		rc_tab->size = newsize;
+		rc_tab->scan = newkeymap;
+		spin_unlock_irqrestore(&rc_tab->lock, flags);
+
+		/* Frees the old keytable */
+		kfree(oldkeymap);
+	} else {
+		rc_tab->size = newsize;
+		spin_unlock_irqrestore(&rc_tab->lock, flags);
+	}
+}
+
+/**
+ * ir_insert_key() - insert a keycode at the table
+ * @rc_tab:		keycode table
+ * @scancode:	the desired scancode
+ * @keycode:	the keycode to be retorned.
+ *
+ */
+static int ir_insert_key(struct ir_scancode_table *rc_tab,
+			  int scancode, int keycode)
+{
+	unsigned long flags;
+	int elem = rc_tab->size;
+	int newsize = rc_tab->size + 1;
+	int resize = ir_is_resize_needed(rc_tab, newsize);
+	struct ir_scancode *oldkeymap = rc_tab->scan;
+	struct ir_scancode *newkeymap;
+
+	if (resize) {
+		newkeymap = kzalloc(ir_roundup_tablesize(newsize) *
+				    sizeof(*newkeymap), GFP_ATOMIC);
+		if (!newkeymap)
+			return -ENOMEM;
+
+		memcpy(newkeymap, oldkeymap,
+		       rc_tab->size * sizeof(*newkeymap));
+	} else
+		newkeymap  = oldkeymap;
+
+	/* Stores the new code at the table */
+	IR_dprintk(1, "#%d: New scan 0x%04x with key 0x%04x\n",
+		   rc_tab->size, scancode, keycode);
+
+	spin_lock_irqsave(&rc_tab->lock, flags);
+	rc_tab->size = newsize;
+	if (resize) {
+		rc_tab->scan = newkeymap;
+		kfree(oldkeymap);
+	}
+	newkeymap[elem].scancode = scancode;
+	newkeymap[elem].keycode  = keycode;
+	spin_unlock_irqrestore(&rc_tab->lock, flags);
+
+	return 0;
+}
+
+/**
+ * ir_setkeycode() - set a keycode at the evdev scancode ->keycode table
+ * @dev:	the struct input_dev device descriptor
+ * @scancode:	the desired scancode
+ * @keycode:	the keycode to be retorned.
+ *
+ * This routine is used to handle evdev EVIOCSKEY ioctl.
+ * There's one caveat here: how can we increase the size of the table?
+ * If the key is not found, returns -EINVAL, otherwise, returns 0.
+ */
+static int ir_setkeycode(struct input_dev *dev,
+			 int scancode, int keycode)
+{
+	int rc = 0;
+	struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
+	struct ir_scancode *keymap = rc_tab->scan;
+	unsigned long flags;
+
+	/*
+	 * Handle keycode table deletions
+	 *
+	 * If userspace is adding a KEY_UNKNOWN or KEY_RESERVED,
+	 * deal as a trial to remove an existing scancode attribution
+	 * if table become too big, reduce it to save space
+	 */
+	if (keycode == KEY_UNKNOWN || keycode == KEY_RESERVED) {
+		rc = ir_seek_table(rc_tab, scancode);
+		if (rc < 0)
+			return 0;
+
+		IR_dprintk(1, "#%d: Deleting scan 0x%04x\n", rc, scancode);
+		clear_bit(keymap[rc].keycode, dev->keybit);
+		ir_delete_key(rc_tab, rc);
+
+		return 0;
+	}
+
+	/*
+	 * Handle keycode replacements
+	 *
+	 * If the scancode exists, just replace by the new value
+	 */
+	rc = ir_seek_table(rc_tab, scancode);
+	if (rc >= 0) {
+		IR_dprintk(1, "#%d: Replacing scan 0x%04x with key 0x%04x\n",
+			rc, scancode, keycode);
+
+		clear_bit(keymap[rc].keycode, dev->keybit);
+
+		spin_lock_irqsave(&rc_tab->lock, flags);
+		keymap[rc].keycode = keycode;
+		spin_unlock_irqrestore(&rc_tab->lock, flags);
+
+		set_bit(keycode, dev->keybit);
+
+		return 0;
+	}
+
+	/*
+	 * Handle new scancode inserts
+	 *
+	 * reallocate table if needed and insert a new keycode
+	 */
+
+	/* Avoid growing the table indefinitely */
+	if (rc_tab->size + 1 > IR_TAB_MAX_SIZE)
+		return -EINVAL;
+
+	rc = ir_insert_key(rc_tab, scancode, keycode);
+	if (rc < 0)
+		return rc;
+	set_bit(keycode, dev->keybit);
+
+	return 0;
+}
+
+/**
+ * ir_g_keycode_from_table() - gets the keycode that corresponds to a scancode
+ * @input_dev:	the struct input_dev descriptor of the device
+ * @scancode:	the scancode that we're seeking
+ *
+ * This routine is used by the input routines when a key is pressed at the
+ * IR. The scancode is received and needs to be converted into a keycode.
+ * If the key is not found, it returns KEY_UNKNOWN. Otherwise, returns the
+ * corresponding keycode from the table.
+ */
+u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode)
+{
+	struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
+	struct ir_scancode *keymap = rc_tab->scan;
+	int elem;
+
+	elem = ir_seek_table(rc_tab, scancode);
+	if (elem >= 0) {
+		IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n",
+			   dev->name, scancode, keymap[elem].keycode);
+
+		return rc_tab->scan[elem].keycode;
+	}
+
+	printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n",
+	       dev->name, scancode);
+
+	/* Reports userspace that an unknown keycode were got */
+	return KEY_RESERVED;
+}
+
+/**
+ * ir_set_keycode_table() - sets the IR keycode table and add the handlers
+ *			    for keymap table get/set
+ * @input_dev:	the struct input_dev descriptor of the device
+ * @rc_tab:	the struct ir_scancode_table table of scancode/keymap
+ *
+ * This routine is used to initialize the input infrastructure to work with
+ * an IR.
+ * It should be called before registering the IR device.
+ */
+int ir_set_keycode_table(struct input_dev *input_dev,
+			 struct ir_scancode_table *rc_tab)
+{
+	struct ir_scancode *keymap = rc_tab->scan;
+	int i;
+
+	spin_lock_init(&rc_tab->lock);
+
+	if (rc_tab->scan == NULL || !rc_tab->size)
+		return -EINVAL;
+
+	/* set the bits for the keys */
+	IR_dprintk(1, "key map size: %d\n", rc_tab->size);
+	for (i = 0; i < rc_tab->size; i++) {
+		IR_dprintk(1, "#%d: setting bit for keycode 0x%04x\n",
+			i, keymap[i].keycode);
+		set_bit(keymap[i].keycode, input_dev->keybit);
+	}
+
+	input_dev->getkeycode = ir_getkeycode;
+	input_dev->setkeycode = ir_setkeycode;
+	input_set_drvdata(input_dev, rc_tab);
+
+	return 0;
+}
+
+void ir_input_free(struct input_dev *dev)
+{
+	struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
+
+	if (!rc_tab)
+		return;
+
+	IR_dprintk(1, "Freed keycode table\n");
+
+	rc_tab->size = 0;
+	kfree(rc_tab->scan);
+	rc_tab->scan = NULL;
+}
+EXPORT_SYMBOL_GPL(ir_input_free);
+