[PATCH 1/3] input: goldfish_events: add devicetree bindings

From: Greg Hackmann <redacted>

Add device tree bindings to the Goldfish virtual platform event driver.

Signed-off-by: Greg Hackmann <redacted>
Signed-off-by: Jin Qian <redacted>
Signed-off-by: Alan <redacted>
---
 .../devicetree/bindings/goldfish/events.txt        |   17 +++++++++++++++++
 drivers/input/keyboard/goldfish_events.c           |    7 +++++++
 2 files changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/goldfish/events.txt

diff --git a/Documentation/devicetree/bindings/goldfish/events.txt b/Documentation/devicetree/bindings/goldfish/events.txt
new file mode 100644
index 0000000..c270066
--- /dev/null
+++ b/Documentation/devicetree/bindings/goldfish/events.txt

@@ -0,0 +1,17 @@
+Android Goldfish Events Keypad
+
+Android goldfish events keypad device generated by android emulator.
+
+Required properties:
+
+- compatible : should contain "google,goldfish-events-keypad" to match emulator
+- reg        : <registers mapping>
+- interrupts : <interrupt mapping>
+
+Example:
+
+	goldfish-events@9040000 {
+		compatible = "google,goldfish-events-keypad";
+		reg = <0x9040000 0x1000>;
+		interrupts = <0x5>;
+	};

diff --git a/drivers/input/keyboard/goldfish_events.c b/drivers/input/keyboard/goldfish_events.c
index 907e4e2..b11d218 100644
--- a/drivers/input/keyboard/goldfish_events.c
+++ b/drivers/input/keyboard/goldfish_events.c

@@ -178,10 +178,17 @@ static int events_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id goldfish_events_of_match[] = {
+	{ .compatible = "google,goldfish-events-keypad", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, goldfish_events_of_match);
+
 static struct platform_driver events_driver = {
 	.probe	= events_probe,
 	.driver	= {
 		.name	= "goldfish_events",
+		.of_match_table = goldfish_events_of_match,
 	},
 };
 

From: Jason Hu <redacted>

Add ACPI binding to the goldfish events driver.

Signed-off-by: Jason Hu <redacted>
Signed-off-by: Jin Qian <redacted>
Signed-off-by: Alan <redacted>
---
 drivers/input/keyboard/goldfish_events.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/input/keyboard/goldfish_events.c b/drivers/input/keyboard/goldfish_events.c
index b11d218..c7e308a 100644
--- a/drivers/input/keyboard/goldfish_events.c
+++ b/drivers/input/keyboard/goldfish_events.c

@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 #include <linux/irq.h>
 #include <linux/io.h>
+#include <linux/acpi.h>
 
 enum {
 	REG_READ        = 0x00,

@@ -184,11 +185,18 @@ static const struct of_device_id goldfish_events_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, goldfish_events_of_match);
 
+static const struct acpi_device_id goldfish_events_acpi_match[] = {
+	{ "GFSH0002", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, goldfish_events_acpi_match);
+
 static struct platform_driver events_driver = {
 	.probe	= events_probe,
 	.driver	= {
 		.name	= "goldfish_events",
 		.of_match_table = goldfish_events_of_match,
+		.acpi_match_table = ACPI_PTR(goldfish_events_acpi_match),
 	},
 };
 

From: Lingfeng Yang <redacted>

If we send SYN_REPORT on every single multi-touch event, it breaks the
multi-touch.

The multi-touch becomes jerky and you have to click 2-3 times to do things
while randomly activating notification bars when not clicking.

If we suppress these SYN_REPORTS, multi-touch will work fine and the events
will have a protocol that looks nice.

We need to register Goldfish Events as a multi-touch 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, causing touches of more than one
finger to fail.

Signed-off-by: Lingfeng Yang <redacted>
Signed-off-by: Jin Qian <redacted>
Signed-off-by: Alan Cox <redacted>
---
 drivers/input/keyboard/goldfish_events.c |   30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/input/keyboard/goldfish_events.c b/drivers/input/keyboard/goldfish_events.c
index c7e308a..c0d77b7 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 +55,23 @@ 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;
 }
 

@@ -154,6 +173,15 @@ 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 multi-touch.
+	 * 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 multi-touch with more than one finger from working.
+	 * See drivers/input/input.c:input_handle_abs_event.
+	 */
+	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);

On Fri, Feb 26, 2016 at 06:50:21PM +0000, Alan wrote:

That would be error in that keyboard driver and should be fixed.

+	 * 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);

I'd rather we always rely on the host to send the SYN event.

Can we use data retrieved by events_import_abs_params() to set up
correct number of slots? Also we need error handling. And possibly
retrieve correct properties to set pass to input_mt_init_slots()...

 
 	events_import_bits(edev, input_dev->evbit, EV_SYN, EV_MAX);
 	events_import_bits(edev, input_dev->keybit, EV_KEY, KEY_MAX);

Thanks.

-- 
Dmitry

On Fri, Feb 26, 2016 at 06:49:34PM +0000, Alan wrote:

From: Greg Hackmann <redacted>

Add device tree bindings to the Goldfish virtual platform event driver.

Signed-off-by: Greg Hackmann <redacted>
Signed-off-by: Jin Qian <redacted>
Signed-off-by: Alan <redacted>

Applied, thank you.

-- 
Dmitry

On Fri, Feb 26, 2016 at 06:49:56PM +0000, Alan wrote:

I believe this can we guarded by #ifdef CONFIG_ACPI, I'll add it.

+
 static struct platform_driver events_driver = {
 	.probe	= events_probe,
 	.driver	= {
 		.name	= "goldfish_events",
 		.of_match_table = goldfish_events_of_match,
+		.acpi_match_table = ACPI_PTR(goldfish_events_acpi_match),
 	},
 };
 

Thanks.

-- 
Dmitry

quoted

 	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.

That would be error in that keyboard driver and should be fixed.

Agreed but it's still the case that current and long standing Goldfish
behaviour requires the above.

quoted

+	 * 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);

I'd rather we always rely on the host to send the SYN event.

That would certainly make sense for the future.

quoted

+
 	return IRQ_HANDLED;
 }
 

@@ -154,6 +173,15 @@ 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 multi-touch.
+	 * 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 multi-touch with more than one finger from
working.
+	 * See drivers/input/input.c:input_handle_abs_event.
+	 */
+	input_mt_init_slots(input_dev, GOLDFISH_MAX_FINGERS, 0);

Can we use data retrieved by events_import_abs_params() to set up
correct number of slots? Also we need error handling. And possibly
retrieve correct properties to set pass to input_mt_init_slots()...

Again - I agree that makes sense for future versions of Goldfish

Alan