From: Lingfeng Yang <lfy@xxxxxxxxxx>
Register Goldfish Events device properly as a multitouch device,
and send SYN_REPORT event in appropriate cases only.
If SYN_REPORT is sent on every single multitouch event, it breaks
the multitouch. The multitouch becomes janky and having to click
2-3 times to do stuff (plus randomly activating notification bars
when not clicking). If these SYN_REPORT events are supressed,
multitouch will work fine, plus the events will have a protocol
that looks nice.
In addition, Goldfish Events device needs to be registerd as a
multitouch device by issuing input_mt_init_slots. Otherwise,
input_handle_abs_event in drivers/input/input.c will silently drop
all ABS_MT_SLOT events, casusing touches with more than one finger
not to work properly.
Signed-off-by: Lingfeng Yang <lfy@xxxxxxxxxx>
Signed-off-by: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
Signed-off-by: Goran Ferenc <goran.ferenc@xxxxxxxxxx>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>
---
drivers/input/keyboard/goldfish_events.c | 33 +++++++++++++++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/drivers/input/keyboard/goldfish_events.c b/drivers/input/keyboard/goldfish_events.c
index f6e643b..6e0b8bb 100644
--- a/drivers/input/keyboard/goldfish_events.c
+++ b/drivers/input/keyboard/goldfish_events.c
@@ -17,6 +17,7 @@
#include <linux/interrupt.h>
#include <linux/types.h>
#include <linux/input.h>
+#include <linux/input/mt.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
@@ -24,6 +25,8 @@
#include <linux/io.h>
#include <linux/acpi.h>
+#define GOLDFISH_MAX_FINGERS 5
+
enum {
REG_READ = 0x00,
REG_SET_PAGE = 0x00,
@@ -52,7 +55,22 @@ static irqreturn_t events_interrupt(int irq, void *dev_id)
value = __raw_readl(edev->addr + REG_READ);
input_event(edev->input, type, code, value);
- input_sync(edev->input);
+
+ /*
+ * Send an extra (EV_SYN, SYN_REPORT, 0x0) event if a key
+ * was pressed. Some keyboard device drivers may only send
+ * the EV_KEY event and not EV_SYN.
+ *
+ * Note that sending an extra SYN_REPORT is not necessary
+ * nor correct protocol with other devices such as
+ * touchscreens, which will send their own SYN_REPORT's
+ * when sufficient event information has been collected
+ * (e.g., for touchscreens, when pressure and X/Y coordinates
+ * have been received). Hence, we will only send this extra
+ * SYN_REPORT if type == EV_KEY.
+ */
+ if (type == EV_KEY)
+ input_sync(edev->input);
return IRQ_HANDLED;
}
@@ -155,6 +173,19 @@ static int events_probe(struct platform_device *pdev)
input_dev->name = edev->name;
input_dev->id.bustype = BUS_HOST;
+ /*
+ * Set the Goldfish Device to be multitouch.
+ *
+ * In the Ranchu kernel, there is multitouch-specific code
+ * for handling ABS_MT_SLOT events (see
+ * drivers/input/input.c:input_handle_abs_event).
+ * If we do not issue input_mt_init_slots, the kernel will
+ * filter out needed ABS_MT_SLOT events when we touch the
+ * screen in more than one place, preventing multitouch with
+ * more than one finger from working.
+ */
+ input_mt_init_slots(input_dev, GOLDFISH_MAX_FINGERS, 0);
+
events_import_bits(edev, input_dev->evbit, EV_SYN, EV_MAX);
events_import_bits(edev, input_dev->keybit, EV_KEY, KEY_MAX);
events_import_bits(edev, input_dev->relbit, EV_REL, REL_MAX);
--
2.7.4
