This patch adds the ability to extract MT slot data via a new ioctl,
EVIOCGMTSLOTS. The function returns an array of slot values for the
specified ABS_MT event type.
Example of user space usage:
struct { unsigned code; int values[64]; } req;
req.code = ABS_MT_POSITION_X;
if (ioctl(fd, EVIOCGMTSLOTS(sizeof(req)), &req) < 0)
return -1;
for (i = 0; i < 64; i++)
printf("slot %d: %d\n", i, req.values[i]);
Signed-off-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>
---
Here is the fourth version of the patch.
Rather than over-specifying the ioctl binary format by introducing a
struct object that does not fit everyone, this version simply leaves
all object definitions to userland.
Thanks,
Henrik
drivers/input/evdev.c | 27 ++++++++++++++++++++++++++-
include/linux/input.h | 25 +++++++++++++++++++++++++
2 files changed, 51 insertions(+), 1 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 76457d5..e4cad16 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -20,7 +20,7 @@
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
-#include <linux/input.h>
+#include <linux/input/mt.h>
#include <linux/major.h>
#include <linux/device.h>
#include "input-compat.h"
@@ -623,6 +623,28 @@ static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
return input_set_keycode(dev, &ke);
}
+static int evdev_handle_mt_request(struct input_dev *dev,
+ unsigned int size,
+ int __user *ip)
+{
+ const struct input_mt_slot *mt = dev->mt;
+ unsigned int code;
+ int max_slots;
+ int i;
+
+ if (get_user(code, &ip[0]))
+ return -EFAULT;
+ if (!input_is_mt_value(code))
+ return -EINVAL;
+
+ max_slots = (size - sizeof(__u32)) / sizeof(__s32);
+ for (i = 0; i < dev->mtsize && i < max_slots; i++)
+ if (put_user(input_mt_get_value(&mt[i], code), &ip[1 + i]))
+ return -EFAULT;
+
+ return 0;
+}
+
static long evdev_do_ioctl(struct file *file, unsigned int cmd,
void __user *p, int compat_mode)
{
@@ -708,6 +730,9 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
return bits_to_user(dev->propbit, INPUT_PROP_MAX,
size, p, compat_mode);
+ case EVIOCGMTSLOTS(0):
+ return evdev_handle_mt_request(dev, size, ip);
+
case EVIOCGKEY(0):
return bits_to_user(dev->key, KEY_MAX, size, p, compat_mode);
diff --git a/include/linux/input.h b/include/linux/input.h
index 3862e32..af26443 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -114,6 +114,31 @@ struct input_keymap_entry {
#define EVIOCGUNIQ(len) _IOC(_IOC_READ, 'E', 0x08, len) /* get unique identifier */
#define EVIOCGPROP(len) _IOC(_IOC_READ, 'E', 0x09, len) /* get device properties */
+/**
+ * EVIOCGMTSLOTS(len) - get MT slot values
+ *
+ * The ioctl buffer argument should be binary equivalent to
+ *
+ * struct input_mt_request_layout {
+ * __u32 code;
+ * __s32 values[num_slots];
+ * };
+ *
+ * where num_slots is the (arbitrary) number of MT slots to extract.
+ *
+ * The ioctl size argument (len) is the size of the buffer, which
+ * should satisfy len = (num_slots + 1) * sizeof(__s32). If len is
+ * too small to fit all available slots, the first num_slots are
+ * returned.
+ *
+ * Before the call, code is set to the wanted ABS_MT event type. On
+ * return, values[] is filled with the slot values for the specified
+ * ABS_MT code.
+ *
+ * If the request code is not an ABS_MT value, -EINVAL is returned.
+ */
+#define EVIOCGMTSLOTS(len) _IOC(_IOC_READ, 'E', 0x0a, len)
+
#define EVIOCGKEY(len) _IOC(_IOC_READ, 'E', 0x18, len) /* get global key state */
#define EVIOCGLED(len) _IOC(_IOC_READ, 'E', 0x19, len) /* get all LEDs */
#define EVIOCGSND(len) _IOC(_IOC_READ, 'E', 0x1a, len) /* get all sounds status */
--
1.7.9
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
