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 351b98b9b302..169b337b7c9d 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 000000000000..2de7caeef437
--- /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 5964145d65e6..805f1e09770f 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;