Merge branch 'for-4.15/multitouch' into for-linus

[sfrench/cifs-2.6.git] / drivers / hid / hid-multitouch.c

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 9e8c4d2ba11d2cc7c2559f34dc46fe646640e131..86fd7f4b1b26552774794a3be39958b123e9eaba 100644 (file)
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -43,6 +43,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/input/mt.h>
+#include <linux/jiffies.h>
 #include <linux/string.h>
 #include <linux/timer.h>
 
@@ -136,6 +137,9 @@ struct mt_device {
        bool serial_maybe;      /* need to check for serial protocol */
        bool curvalid;          /* is the current contact valid? */
        unsigned mt_flags;      /* flags to pass to input-mt */
+       __s32 dev_time;         /* the scan time provided by the device */
+       unsigned long jiffies;  /* the frame's jiffies */
+       int timestamp;          /* the timestamp to be sent */
 };
 
 static void mt_post_parse_default_settings(struct mt_device *td);
@@ -177,6 +181,12 @@ static void mt_post_parse(struct mt_device *td);
 #define MT_DEFAULT_MAXCONTACT  10
 #define MT_MAX_MAXCONTACT      250
 
+/*
+ * Resync device and local timestamps after that many microseconds without
+ * receiving data.
+ */
+#define MAX_TIMESTAMP_INTERVAL 1000000
+
 #define MT_USB_DEVICE(v, p)    HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH, v, p)
 #define MT_BT_DEVICE(v, p)     HID_DEVICE(BUS_BLUETOOTH, HID_GROUP_MULTITOUCH, v, p)
 
@@ -583,6 +593,12 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                                cls->sn_pressure);
                        mt_store_field(usage, td, hi);
                        return 1;
+               case HID_DG_SCANTIME:
+                       hid_map_usage(hi, usage, bit, max,
+                               EV_MSC, MSC_TIMESTAMP);
+                       input_set_capability(hi->input, EV_MSC, MSC_TIMESTAMP);
+                       mt_store_field(usage, td, hi);
+                       return 1;
                case HID_DG_CONTACTCOUNT:
                        /* Ignore if indexes are out of bounds. */
                        if (field->index >= field->report->maxfield ||
@@ -718,6 +734,7 @@ static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
 static void mt_sync_frame(struct mt_device *td, struct input_dev *input)
 {
        input_mt_sync_frame(input);
+       input_event(input, EV_MSC, MSC_TIMESTAMP, td->timestamp);
        input_sync(input);
        td->num_received = 0;
        if (test_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags))
@@ -727,6 +744,28 @@ static void mt_sync_frame(struct mt_device *td, struct input_dev *input)
        clear_bit(MT_IO_FLAGS_ACTIVE_SLOTS, &td->mt_io_flags);
 }
 
+static int mt_compute_timestamp(struct mt_device *td, struct hid_field *field,
+               __s32 value)
+{
+       long delta = value - td->dev_time;
+       unsigned long jdelta = jiffies_to_usecs(jiffies - td->jiffies);
+
+       td->jiffies = jiffies;
+       td->dev_time = value;
+
+       if (delta < 0)
+               delta += field->logical_maximum;
+
+       /* HID_DG_SCANTIME is expressed in 100us, we want it in us. */
+       delta *= 100;
+
+       if (jdelta > MAX_TIMESTAMP_INTERVAL)
+               /* No data received for a while, resync the timestamp. */
+               return 0;
+       else
+               return td->timestamp + delta;
+}
+
 static int mt_touch_event(struct hid_device *hid, struct hid_field *field,
                                struct hid_usage *usage, __s32 value)
 {
@@ -787,6 +826,9 @@ static void mt_process_mt_event(struct hid_device *hid, struct hid_field *field,
                case HID_DG_HEIGHT:
                        td->curdata.h = value;
                        break;
+               case HID_DG_SCANTIME:
+                       td->timestamp = mt_compute_timestamp(td, field, value);
+                       break;
                case HID_DG_CONTACTCOUNT:
                        break;
                case HID_DG_TOUCH: