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: Atif Niyaz <atifniyaz@google.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 8 insertions, 27 deletions

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 867c2cfd0038..d7dd6fcf2db0 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -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();