Several devices use a high number of bits for scancodes. One important
group is the Remote Controllers. Some new protocols like RC-6 define a
scancode space of 64 bits.
The current EVIO[CS]GKEYCODE ioctls allow replace the scancode/keycode
translation tables, but it is limited to up to 32 bits for scancode.
Also, if userspace wants to clean the existing table, replacing it by
a new one, it needs to run a loop calling the old ioctls, over the
entire sparsed scancode userspace.
To solve those problems, this patch introduces two new ioctls:
EVIOCGKEYCODEBIG - reads a scancode from the translation table;
EVIOSGKEYCODEBIG - writes a scancode into the translation table.
The EVIOSGKEYCODEBIG can also be used to cleanup the translation entries
by associating KEY_RESERVED to a scancode.
EVIOCGKEYCODEBIG uses kt_entry::index field in order to retrieve a keycode
from the table. This field is unused on EVIOSGKEYCODEBIG.
By default, kernel will implement a default handler that will work with
both EVIO[CS]GKEYCODEBIG and the legacy EVIO[CS]GKEYCODE ioctls.
Compatibility code were also added to allow drivers that implement
only the ops handler for EVIO[CS]GKEYCODE to keep working.
Userspace compatibility for EVIO[CS]GKEYCODE is also granted: the evdev/input
ioctl handler will automatically map those ioctls with the new
getkeycodebig()/setkeycodebig() operations to handle a request using the
legacy API.
So, new drivers should only implement the EVIO[CS]GKEYCODEBIG operation
handlers: getkeycodebig()/setkeycodebig().
Signed-off-by: Mauro Carvalho Chehab
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 258c639..1730b5b 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -513,6 +513,8 @@ static long evdev_do_ioctl(struct file *file, unsigned int
cmd,
struct input_absinfo abs;
struct ff_effect effect;
int __user *ip = (int __user *)p;
+ struct keycode_table_entry kt, *kt_p = p;
+ char scancode[16];
int i, t, u, v;
int error;
@@ -567,6 +569,43 @@ static long evdev_do_ioctl(struct file *file, unsigned int
cmd,
return input_set_keycode(dev, t, v);
+ case EVIOCGKEYCODEBIG:
+ if (copy_from_user(&kt, kt_p, sizeof(kt)))
+ return -EFAULT;
+
+ if (kt.len > sizeof(scancode))
+ return -EINVAL;
+
+ kt.scancode = scancode;
+
+ error = input_get_keycode_big(dev, &kt);
+ if (error)
+ return error;
+
+ if (copy_to_user(kt_p, &kt, sizeof(kt)))
+ return -EFAULT;
+
+ /* FIXME: probably need some compat32 code */
+ if (copy_to_user(kt_p->scancode, kt.scancode, kt.len))
+ return -EFAULT;
+
+ return 0;
+
+ case EVIOCSKEYCODEBIG:
+ if (copy_from_user(&kt, kt_p, sizeof(kt)))
+ return -EFAULT;
+
+ if (kt.len > sizeof(scancode))
+ return -EINVAL;
+
+ kt.scancode = scancode;
+
+ /* FIXME: probably need some compat32 code */
+ if (copy_from_user(kt.scancode, kt_p->scancode, kt.len))
+ return -EFAULT;
+
+ return input_set_keycode_big(dev, &kt);
+
case EVIOCRMFF:
return input_ff_erase(dev, (int)(unsigned long) p, file);
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 86cb2d2..d2bb5b5 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -551,6 +551,11 @@ static void input_disconnect_device(struct input_dev *dev)
spin_unlock_irq(&dev->event_lock);
}
+/*
+ * Those routines handle the default case where no [gs]etkeycode() is
+ * defined. In this case, an array indexed by the scancode is used.
+ */
+
static int input_fetch_keycode(struct input_dev *dev, int scancode)
{
switch (dev->keycodesize) {
@@ -565,25 +570,74 @@ static int input_fetch_keycode(struct input_dev *dev, int
scancode)
}
}
-static int input_default_getkeycode(struct input_dev *dev,
- int scancode, int *keycode)
+/*
+ * Supports only 8, 16 and 32 bit scancodes. It wouldn't be that
+ * hard to write some machine-endian logic to support 24 bit scancodes,
+ * but it seemed overkill. It should also be noticed that, since there
+ * are, in general, less than 256 scancodes sparsed into the scancode
+ * space, even with 16 bits, the codespace is sparsed, with leads into
+ * memory and code ineficiency, when retrieving the entire scancode
+ * space.
+ * So, it is highly recommended to implement getkeycodebig/setkeycodebig
+ * instead of using a normal table approach, when more than 8 bits is
+ * needed for the scancode.
+ */
+static int input_fetch_scancode(struct keycode_table_entry *kt_entry,
+ u32 *scancode)
{
+ switch (k
