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();