V4L/DVB (13532): ir-common: Add infrastructure to use a dynamic keycode table

V4L drivers use an static keycode vector with 128 entries, where the scancode
indexes the keycode. While this works, it limits the scancodes to have only
7 bits, not allowing for example full RC5 codes.

Instead of implementing the same code on every V4L driver, provide a common
infrastructure to handle the bigger tables, minimizing the changes inside
each driver.

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

3 files changed, 168 insertions, 2 deletions

diff --git a/drivers/media/common/Makefile b/drivers/media/common/Makefile
index 351b98b..169b337 100644
--- a/drivers/media/common/Makefile
+++ b/drivers/media/common/Makefile
@@ -1,6 +1,6 @@
 saa7146-objs    := saa7146_i2c.o saa7146_core.o
 saa7146_vv-objs := saa7146_fops.o saa7146_video.o saa7146_hlp.o saa7146_vbi.o
-ir-common-objs  := ir-functions.o ir-keymaps.o
+ir-common-objs  := ir-functions.o ir-keymaps.o ir-keytable.o
 
 obj-y += tuners/
 obj-$(CONFIG_VIDEO_SAA7146) += saa7146.o
diff --git a/drivers/media/common/ir-keytable.c b/drivers/media/common/ir-keytable.c
new file mode 100644
index 0000000..2de7cae
--- /dev/null
+++ b/drivers/media/common/ir-keytable.c
@@ -0,0 +1,156 @@
+/* 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>
+
+/**
+ * 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 i;
+	struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
+	struct ir_scancode *keymap = rc_tab->scan;
+
+	/* See if we can match the raw key code. */
+	for (i = 0; i < rc_tab->size; i++)
+		if (keymap[i].scancode == scancode) {
+			*keycode = keymap[i].keycode;
+			return 0;
+		}
+
+	/*
+	 * If is there extra space, returns KEY_RESERVED,
+	 * otherwise, input core won't let ir_setkeycode
+	 * to work
+	 */
+	for (i = 0; i < rc_tab->size; i++)
+		if (keymap[i].keycode == KEY_RESERVED ||
+		    keymap[i].keycode == KEY_UNKNOWN) {
+			*keycode = KEY_RESERVED;
+			return 0;
+		}
+
+	return -EINVAL;
+}
+
+/**
+ * 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 i;
+	struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
+	struct ir_scancode *keymap = rc_tab->scan;
+
+	/* Search if it is replacing an existing keycode */
+	for (i = 0; i < rc_tab->size; i++)
+		if (keymap[i].scancode == scancode) {
+			keymap[i].keycode = keycode;
+			return 0;
+		}
+
+	/* Search if is there a clean entry. If so, use it */
+	for (i = 0; i < rc_tab->size; i++)
+		if (keymap[i].keycode == KEY_RESERVED ||
+		    keymap[i].keycode == KEY_UNKNOWN) {
+			keymap[i].scancode = scancode;
+			keymap[i].keycode = keycode;
+			return 0;
+		}
+
+	/*
+	 * FIXME: Currently, it is not possible to increase the size of
+	 * scancode table. For it to happen, one possibility
+	 * would be to allocate a table with key_map_size + 1,
+	 * copying data, appending the new key on it, and freeing
+	 * the old one - or maybe just allocating some spare space
+	 */
+
+	return -EINVAL;
+}
+
+/**
+ * ir_g_keycode_from_table() - gets the keycode that corresponds to a scancode
+ * @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.
+ */
+u32 ir_g_keycode_from_table(struct input_dev *dev, u32 scancode)
+{
+	int i;
+	struct ir_scancode_table *rc_tab = input_get_drvdata(dev);
+	struct ir_scancode *keymap = rc_tab->scan;
+
+	for (i = 0; i < rc_tab->size; i++)
+		if (keymap[i].scancode == scancode) {
+			IR_dprintk(1, "%s: scancode 0x%04x keycode 0x%02x\n",
+				dev->name, scancode, keymap[i].keycode);
+
+			return keymap[i].keycode;
+		}
+
+	printk(KERN_INFO "%s: unknown key for scancode 0x%04x\n",
+	       dev->name, scancode);
+
+	return KEY_UNKNOWN;
+}
+EXPORT_SYMBOL_GPL(ir_g_keycode_from_table);
+
+/**
+ * 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 requires that the caller initializes the input_dev struct with
+ * some fields: name,
+ */
+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;
+
+	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;
+}
+EXPORT_SYMBOL_GPL(ir_set_keycode_table);
diff --git a/include/media/ir-common.h b/include/media/ir-common.h
index 5964145d6..805f1e0 100644
--- a/include/media/ir-common.h
+++ b/include/media/ir-common.h
@@ -106,6 +106,8 @@ struct card_ir {
 	struct tasklet_struct   tlet;
 };
 
+/* Routines from ir-functions.c */
+
 void ir_input_init(struct input_dev *dev, struct ir_input_state *ir,
 		   int ir_type, struct ir_scancode_table *ir_codes);
 void ir_input_nokey(struct input_dev *dev, struct ir_input_state *ir);
@@ -120,7 +122,15 @@ u32  ir_rc5_decode(unsigned int code);
 void ir_rc5_timer_end(unsigned long data);
 void ir_rc5_timer_keyup(unsigned long data);
 
-/* Keymaps to be used by other modules */
+/* Routines from ir-keytable.c */
+
+u32 ir_g_keycode_from_table(struct input_dev *input_dev,
+			    u32 scancode);
+
+int ir_set_keycode_table(struct input_dev *input_dev,
+			 struct ir_scancode_table *rc_tab);
+
+/* scancode->keycode map tables from ir-keymaps.c */
 
 extern struct ir_scancode_table ir_codes_empty_table;
 extern struct ir_scancode_table ir_codes_avermedia_table;