[PATCH 2/2] Input: Add EVIOC mechanism for MT slots
From: Henrik Rydberg <hidden>
Date: 2012-01-12 19:24:44
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
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 <redacted>
Signed-off-by: Henrik Rydberg <redacted>
---
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