Input: evdev - add CLOCK_BOOTTIME support

This patch adds support for CLOCK_BOOTTIME for input event timestamp.
CLOCK_BOOTTIME includes suspend time, so it would allow aplications
to get correct time difference between two events even when system
resumes from suspend state.

Signed-off-by: Aniroop Mathur <a.mathur@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 44 insertions, 16 deletions

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index bc203485716d..b1a52abc58df 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -28,6 +28,13 @@
 #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;
@@ -49,12 +56,32 @@ struct evdev_client {
         struct fasync_struct *fasync;
         struct evdev *evdev;
         struct list_head node;
-        int clkid;
+        int clk_type;
         bool revoked;
         unsigned int bufsize;
         struct input_event buffer[];
 };
 
+static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
+{
+        switch (clkid) {
+
+        case CLOCK_REALTIME:
+                client->clk_type = EV_CLK_REAL;
+                break;
+        case CLOCK_MONOTONIC:
+                client->clk_type = EV_CLK_MONO;
+                break;
+        case CLOCK_BOOTTIME:
+                client->clk_type = EV_CLK_BOOT;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
 /* flush queued events of type @type, caller must hold client->buffer_lock */
 static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
 {
@@ -108,8 +135,11 @@ static void evdev_queue_syn_dropped(struct evdev_client *client)
         struct input_event ev;
         ktime_t time;
 
-        time = (client->clkid == CLOCK_MONOTONIC) ?
-                ktime_get() : ktime_get_real();
+        time = client->clk_type == EV_CLK_REAL ?
+                        ktime_get_real() :
+                        client->clk_type == EV_CLK_MONO ?
+                                ktime_get() :
+                                ktime_get_boottime();
 
         ev.time = ktime_to_timeval(time);
         ev.type = EV_SYN;
@@ -159,7 +189,7 @@ static void __pass_event(struct evdev_client *client,
 
 static void evdev_pass_values(struct evdev_client *client,
                         const struct input_value *vals, unsigned int count,
-                        ktime_t mono, ktime_t real)
+                        ktime_t *ev_time)
 {
         struct evdev *evdev = client->evdev;
         const struct input_value *v;
@@ -169,8 +199,7 @@ static void evdev_pass_values(struct evdev_client *client,
         if (client->revoked)
                 return;
 
-        event.time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
-                                      mono : real);
+        event.time = ktime_to_timeval(ev_time[client->clk_type]);
 
         /* Interrupts are disabled, just acquire the lock. */
         spin_lock(&client->buffer_lock);
@@ -198,21 +227,22 @@ static void evdev_events(struct input_handle *handle,
 {
         struct evdev *evdev = handle->private;
         struct evdev_client *client;
-        ktime_t time_mono, time_real;
+        ktime_t ev_time[EV_CLK_MAX];
 
-        time_mono = ktime_get();
-        time_real = ktime_mono_to_real(time_mono);
+        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);
 
         rcu_read_lock();
 
         client = rcu_dereference(evdev->grab);
 
         if (client)
-                evdev_pass_values(client, vals, count, time_mono, time_real);
+                evdev_pass_values(client, vals, count, ev_time);
         else
                 list_for_each_entry_rcu(client, &evdev->client_list, node)
-                        evdev_pass_values(client, vals, count,
-                                          time_mono, time_real);
+                        evdev_pass_values(client, vals, count, ev_time);
 
         rcu_read_unlock();
 }
@@ -877,10 +907,8 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
         case EVIOCSCLOCKID:
                 if (copy_from_user(&i, p, sizeof(unsigned int)))
                         return -EFAULT;
-                if (i != CLOCK_MONOTONIC && i != CLOCK_REALTIME)
-                        return -EINVAL;
-                client->clkid = i;
-                return 0;
+
+                return evdev_set_clk_type(client, i);
 
         case EVIOCGKEYCODE:
                 return evdev_handle_get_keycode(dev, p);