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 { struct input_mt_request req; int values[64]; } data;
data.req.code = ABS_MT_POSITION_X;
if (ioctl(fd, EVIOCGMTSLOTS(sizeof(data)), &data) < 0)
return -1;
for (i = 0; i < data.req.num_values; i++)
printf("slot %d: %d\n", i, data.values[i]);
Cc: Chase Douglas <chase.douglas@xxxxxxxxxxxxx>
Signed-off-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>
---
Hi Dmitry,
This is a new take on the MT slot ioctl patch. A new ioctl is added,
which takes a request structure and returns a (variable) array of slot
values. The patch seems to work, but testing has not been extensive (yet).
Cheers,
Henrik
drivers/input/evdev.c | 30 +++++++++++++++++++++++++++++-
include/linux/input.h | 25 +++++++++++++++++++++++++
2 files changed, 54 insertions(+), 1 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 4cf2534..8bf45d4 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"
@@ -621,6 +621,31 @@ 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 i;
+
+ if (get_user(code, &ip[0]))
+ return -EFAULT;
+ if (!input_is_mt_value(code))
+ return -EINVAL;
+
+ if (size < sizeof(struct input_mt_request) + dev->mtsize * sizeof(int))
+ return -EINVAL;
+
+ if (put_user(dev->mtsize, &ip[1]))
+ return -EFAULT;
+ for (i = 0; i < dev->mtsize; i++)
+ if (put_user(input_mt_get_value(&mt[i], code), &ip[2 + i]))
+ return -EFAULT;
+
+ return 0;
+}
+
static long evdev_do_ioctl(struct file *file, unsigned int cmd,
void __user *p, int compat_mode)
{
@@ -706,6 +731,9 @@ 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 a637e78..9a73f18 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -99,6 +99,30 @@ struct input_keymap_entry {
__u8 scancode[32];
};
+/**
+ * struct input_mt_request - used by EVIOCGMTSLOTS ioctl
+ * @code: ABS_MT code to read
+ * @num_values: number of values written to the value array
+ * @values: value array, one value per slot
+ *
+ * The structure is used to retrieve MT slot data. Before the call,
+ * code is set to the wanted ABS_MT event type. On return, the value
+ * array is filled with the slot values for the specified ABS_MT code,
+ * and num_values is set to the actual number of slots.
+ *
+ * The call argument (len) is the size of the return buffer, satisfying
+ *
+ * len >= sizeof(input_mt_request) + sizeof(__s32) * number_of_slots
+ *
+ * If the request code is not an ABS_MT value, or if len is too small,
+ * -EINVAL is returned.
+ */
+struct input_mt_request {
+ __u32 code;
+ __u32 num_values;
+ __s32 values[];
+};
+
#define EVIOCGVERSION _IOR('E', 0x01, int) /* get driver version */
#define EVIOCGID _IOR('E', 0x02, struct input_id) /* get device ID */
#define EVIOCGREP _IOR('E', 0x03, unsigned int[2]) /* get repeat settings */
@@ -113,6 +137,7 @@ struct input_keymap_entry {
#define EVIOCGPHYS(len) _IOC(_IOC_READ, 'E', 0x07, len) /* get physical location */
#define EVIOCGUNIQ(len) _IOC(_IOC_READ, 'E', 0x08, len) /* get unique identifier */
#define EVIOCGPROP(len) _IOC(_IOC_READ, 'E', 0x09, len) /* get device properties */
+#define EVIOCGMTSLOTS(len) _IOC(_IOC_READ, 'E', 0x0a, len) /* get MT slot values */
#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 */
--
1.7.8.1
--
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