Commit 3b51c44b authored by Atif Niyaz's avatar Atif Niyaz Committed by Dmitry Torokhov
Browse files

Input: allow drivers specify timestamp for input events



Currently, evdev stamps events with timestamps acquired in evdev_events()
However, this timestamping may not be accurate in terms of measuring
when the actual event happened.

Let's allow individual drivers specify timestamp in order to provide a more
accurate sense of time for the event. It is expected that drivers will set the
timestamp in their hard interrupt routine.
Signed-off-by: default avatarAtif Niyaz <atifniyaz@google.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent c2433827
......@@ -25,13 +25,6 @@
#include <linux/cdev.h>
#include "input-compat.h"
enum evdev_clock_type {
EV_CLK_REAL = 0,
EV_CLK_MONO,
EV_CLK_BOOT,
EV_CLK_MAX
};
struct evdev {
int open;
struct input_handle handle;
......@@ -53,7 +46,7 @@ struct evdev_client {
struct fasync_struct *fasync;
struct evdev *evdev;
struct list_head node;
unsigned int clk_type;
enum input_clock_type clk_type;
bool revoked;
unsigned long *evmasks[EV_CNT];
unsigned int bufsize;
......@@ -149,17 +142,10 @@ static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
static void __evdev_queue_syn_dropped(struct evdev_client *client)
{
ktime_t *ev_time = input_get_timestamp(client->evdev->handle.dev);
struct timespec64 ts = ktime_to_timespec64(ev_time[client->clk_type]);
struct input_event ev;
ktime_t time;
struct timespec64 ts;
time = client->clk_type == EV_CLK_REAL ?
ktime_get_real() :
client->clk_type == EV_CLK_MONO ?
ktime_get() :
ktime_get_boottime();
ts = ktime_to_timespec64(time);
ev.input_event_sec = ts.tv_sec;
ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
ev.type = EV_SYN;
......@@ -188,18 +174,18 @@ static void evdev_queue_syn_dropped(struct evdev_client *client)
static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
{
unsigned long flags;
unsigned int clk_type;
enum input_clock_type clk_type;
switch (clkid) {
case CLOCK_REALTIME:
clk_type = EV_CLK_REAL;
clk_type = INPUT_CLK_REAL;
break;
case CLOCK_MONOTONIC:
clk_type = EV_CLK_MONO;
clk_type = INPUT_CLK_MONO;
break;
case CLOCK_BOOTTIME:
clk_type = EV_CLK_BOOT;
clk_type = INPUT_CLK_BOOT;
break;
default:
return -EINVAL;
......@@ -307,12 +293,7 @@ static void evdev_events(struct input_handle *handle,
{
struct evdev *evdev = handle->private;
struct evdev_client *client;
ktime_t ev_time[EV_CLK_MAX];
ev_time[EV_CLK_MONO] = ktime_get();
ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
TK_OFFS_BOOT);
ktime_t *ev_time = input_get_timestamp(handle->dev);
rcu_read_lock();
......
......@@ -1894,6 +1894,46 @@ void input_free_device(struct input_dev *dev)
}
EXPORT_SYMBOL(input_free_device);
/**
* input_set_timestamp - set timestamp for input events
* @dev: input device to set timestamp for
* @timestamp: the time at which the event has occurred
* in CLOCK_MONOTONIC
*
* This function is intended to provide to the input system a more
* accurate time of when an event actually occurred. The driver should
* call this function as soon as a timestamp is acquired ensuring
* clock conversions in input_set_timestamp are done correctly.
*
* The system entering suspend state between timestamp acquisition and
* calling input_set_timestamp can result in inaccurate conversions.
*/
void input_set_timestamp(struct input_dev *dev, ktime_t timestamp)
{
dev->timestamp[INPUT_CLK_MONO] = timestamp;
dev->timestamp[INPUT_CLK_REAL] = ktime_mono_to_real(timestamp);
dev->timestamp[INPUT_CLK_BOOT] = ktime_mono_to_any(timestamp,
TK_OFFS_BOOT);
}
EXPORT_SYMBOL(input_set_timestamp);
/**
* input_get_timestamp - get timestamp for input events
* @dev: input device to get timestamp from
*
* A valid timestamp is a timestamp of non-zero value.
*/
ktime_t *input_get_timestamp(struct input_dev *dev)
{
const ktime_t invalid_timestamp = ktime_set(0, 0);
if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
input_set_timestamp(dev, ktime_get());
return dev->timestamp;
}
EXPORT_SYMBOL(input_get_timestamp);
/**
* input_set_capability - mark device as capable of a certain event
* @dev: device that is capable of emitting or accepting event
......
......@@ -33,6 +33,13 @@ struct input_value {
__s32 value;
};
enum input_clock_type {
INPUT_CLK_REAL = 0,
INPUT_CLK_MONO,
INPUT_CLK_BOOT,
INPUT_CLK_MAX
};
/**
* struct input_dev - represents an input device
* @name: name of the device
......@@ -114,6 +121,8 @@ struct input_value {
* @vals: array of values queued in the current frame
* @devres_managed: indicates that devices is managed with devres framework
* and needs not be explicitly unregistered or freed.
* @timestamp: storage for a timestamp set by input_set_timestamp called
* by a driver
*/
struct input_dev {
const char *name;
......@@ -184,6 +193,8 @@ struct input_dev {
struct input_value *vals;
bool devres_managed;
ktime_t timestamp[INPUT_CLK_MAX];
};
#define to_input_dev(d) container_of(d, struct input_dev, dev)
......@@ -382,6 +393,9 @@ void input_close_device(struct input_handle *);
int input_flush_device(struct input_handle *handle, struct file *file);
void input_set_timestamp(struct input_dev *dev, ktime_t timestamp);
ktime_t *input_get_timestamp(struct input_dev *dev);
void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value);
void input_inject_event(struct input_handle *handle, unsigned int type, unsigned int code, int value);
......
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