cypress-touchkey: attempt to filter out "phantom" key-presses

* this issue only affects the fascinate
* this patch attempts to work-around a hardware defect that causes
"phantom" key-presses to be sent during high levels of 3G radio
activity
* based on work by Electric Bill
* reference: http://forum.xda-developers.com/showthread.php?t=1551580

Change-Id: I1fc6f56ad02f31c60a8e399b03d5f0e0b8c1f2df

1 files changed, 42 insertions, 1 deletions

diff --git a/drivers/input/keyboard/cypress-touchkey.c b/drivers/input/keyboard/cypress-touchkey.c
index 7972f27..3514dc1 100755
--- a/drivers/input/keyboard/cypress-touchkey.c
+++ b/drivers/input/keyboard/cypress-touchkey.c
@@ -32,6 +32,12 @@
 #include <linux/miscdevice.h>
 #include <linux/input/cypress-touchkey.h>
 
+#ifdef CONFIG_SAMSUNG_FASCINATE
+#include <mach/gpio.h>
+#include <mach/gpio-aries.h>
+#include <mach/regs-gpio.h>
+#endif
+
 #define SCANCODE_MASK		0x07
 #define UPDOWN_EVENT_MASK	0x08
 #define ESD_STATE_MASK		0x10
@@ -44,6 +50,11 @@
 
 #define DEVICE_NAME "cypress-touchkey"
 
+#ifdef CONFIG_SAMSUNG_FASCINATE
+extern const unsigned long touch_int_flt_width;
+void touch_key_set_int_flt(unsigned long width);
+#endif
+
 int bl_on = 0;
 static DEFINE_SEMAPHORE(enable_sem);
 static DEFINE_SEMAPHORE(i2c_sem);
@@ -179,8 +190,12 @@ static int recovery_routine(struct cypress_touchkey_devdata *devdata)
 		devdata->pdata->touchkey_onoff(TOUCHKEY_ON);
 		ret = i2c_touchkey_read_byte(devdata, &data);
 		if (!ret) {
-			if (!devdata->is_sleeping)
+			if (!devdata->is_sleeping) {
 				enable_irq(irq_eint);
+#ifdef CONFIG_SAMSUNG_FASCINATE
+				touch_key_set_int_flt(touch_int_flt_width);
+#endif
+			}
 			goto out;
 		}
 		dev_err(&devdata->client->dev, "%s: i2c transfer error retry = "
@@ -206,6 +221,19 @@ static irqreturn_t touchkey_interrupt_thread(int irq, void *touchkey_devdata)
 	int scancode;
 	struct cypress_touchkey_devdata *devdata = touchkey_devdata;
 
+#ifdef CONFIG_SAMSUNG_FASCINATE
+	for (i = 0; i < 10; ++i)
+	{
+		ret = gpio_get_value(_3_GPIO_TOUCH_INT);
+
+		if (ret & 1) {
+			dev_err(&devdata->client->dev, "%s: possible phantom key press... "
+					"ignore it!\n", __func__);
+			goto err;
+		}
+	}
+#endif
+
 	ret = i2c_touchkey_read_byte(devdata, &data);
 	if (ret || (data & ESD_STATE_MASK)) {
 		ret = recovery_routine(devdata);
@@ -249,7 +277,13 @@ static irqreturn_t touchkey_interrupt_handler(int irq, void *touchkey_devdata)
 {
 	struct cypress_touchkey_devdata *devdata = touchkey_devdata;
 
+#ifdef CONFIG_SAMSUNG_FASCINATE
+	int i = gpio_get_value(_3_GPIO_TOUCH_INT);
+
+	if ((i & 1) || devdata->is_powering_on) {
+#else
 	if (devdata->is_powering_on) {
+#endif
 		dev_dbg(&devdata->client->dev, "%s: ignoring spurious boot "
 					"interrupt\n", __func__);
 		return IRQ_HANDLED;
@@ -345,6 +379,9 @@ static void cypress_touchkey_early_resume(struct early_suspend *h)
 	}
 	devdata->is_dead = false;
 	enable_irq(devdata->client->irq);
+#ifdef CONFIG_SAMSUNG_FASCINATE
+	touch_key_set_int_flt(touch_int_flt_width);
+#endif
 	devdata->is_powering_on = false;
 	devdata->is_sleeping = false;
 
@@ -502,6 +539,10 @@ static int cypress_touchkey_probe(struct i2c_client *client,
 		goto err_req_irq;
 	}
 
+#ifdef CONFIG_SAMSUNG_FASCINATE
+	touch_key_set_int_flt(touch_int_flt_width);
+#endif
+
 #ifdef CONFIG_HAS_EARLYSUSPEND
 	devdata->early_suspend.suspend = cypress_touchkey_early_suspend;
 	devdata->early_suspend.resume = cypress_touchkey_early_resume;