IOEX: it8801: Enable GPIO based interrupts

Added code to enable GPIO based interrupts on it8801
I/O Expander.

BUG=b:197659347
BRANCH=none
TEST=Tested on ADL-RVP able to get ISR triggered

Change-Id: I7f5f460f48fc21e51bb93bede5a05da89b7dc807
Signed-off-by: Vijay Hiremath <vijay.p.hiremath@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3076469
Reviewed-by: Keith Short <keithshort@chromium.org>
Reviewed-by: Dino Li <Dino.Li@ite.com.tw>
Commit-Queue: Keith Short <keithshort@chromium.org>

1 files changed, 142 insertions, 17 deletions

diff --git a/driver/ioexpander/it8801.c b/driver/ioexpander/it8801.c
index ea59aaa85c..075f53df96 100644
--- a/driver/ioexpander/it8801.c
+++ b/driver/ioexpander/it8801.c
@@ -6,6 +6,7 @@
 #include "common.h"
 #include "console.h"
 #include "gpio.h"
+#include "hooks.h"
 #include "i2c.h"
 #include "ioexpander.h"
 #include "it8801.h"
@@ -19,6 +20,8 @@
 #define CPRINTS(format, args...) cprints(CC_KEYSCAN, format, ## args)
 
 static int it8801_ioex_set_level(int ioex, int port, int mask, int value);
+static void it8801_ioex_event_handler(void);
+DECLARE_DEFERRED(it8801_ioex_event_handler);
 
 static int it8801_read(int reg, int *data)
 {
@@ -60,6 +63,27 @@ static int it8801_check_vendor_id(void)
 	return EC_SUCCESS;
 }
 
+/*
+ * Keyboard and GPIO interrupts are muxed inside the IT8801 chip.
+ * Interrupt enable register controls the individual pins from
+ * triggering this global interrupt hence it is okay that this
+ * pin is enabled all the time.
+ */
+static void it8801_muxed_kbd_gpio_intr_enable(void)
+{
+	static bool intr_enabled;
+
+	/*
+	 * Allow enabling this pin either by Keyboard enable code or
+	 * IOEX init code whichever gets called first.
+	 */
+	if (!intr_enabled) {
+		gpio_clear_pending_interrupt(GPIO_IT8801_SMB_INT);
+		gpio_enable_interrupt(GPIO_IT8801_SMB_INT);
+		intr_enabled = true;
+	}
+}
+
 #ifdef CONFIG_KEYBOARD_NOT_RAW
 void keyboard_raw_init(void)
 {
@@ -183,20 +207,21 @@ test_mockable int keyboard_raw_read_rows(void)
 void keyboard_raw_enable_interrupt(int enable)
 {
 	if (enable) {
+		/* Clear pending iterrupts */
 		it8801_write(IT8801_REG_KSIEER, 0xff);
-		gpio_clear_pending_interrupt(GPIO_IT8801_SMB_INT);
-		gpio_enable_interrupt(GPIO_IT8801_SMB_INT);
-	} else {
-		gpio_disable_interrupt(GPIO_IT8801_SMB_INT);
+
+		/* Enable muxed Keyboard & GPIO interrupt */
+		it8801_muxed_kbd_gpio_intr_enable();
 	}
+
+	it8801_write(IT8801_REG_KSIIER, enable ? 0xff : 0x00);
 }
+#endif /* CONFIG_KEYBOARD_NOT_RAW */
 
 void io_expander_it8801_interrupt(enum gpio_signal signal)
 {
-	/* Wake the scan task */
-	task_wake(TASK_ID_KEYSCAN);
+	hook_call_deferred(&it8801_ioex_event_handler_data, 0);
 }
-#endif /* CONFIG_KEYBOARD_NOT_RAW */
 
 static int it8801_ioex_read(int ioex, int reg, int *data)
 {
@@ -214,6 +239,15 @@ static int it8801_ioex_write(int ioex, int reg, int data)
 			  reg, data);
 }
 
+static int it8801_ioex_update(int ioex, int reg, int data,
+				enum mask_update_action action)
+{
+	struct ioexpander_config_t *ioex_p = &ioex_config[ioex];
+
+	return i2c_update8(ioex_p->i2c_host_port, ioex_p->i2c_addr_flags,
+			  reg, data, action);
+}
+
 static const int it8801_valid_gpio_group[] = {
 	IT8801_VALID_GPIO_G0_MASK,
 	IT8801_VALID_GPIO_G1_MASK,
@@ -249,6 +283,9 @@ static int it8801_ioex_init(int ioex)
 		it8801_gpio_sov[port] = val;
 	}
 
+	/* Enable muxed Keyboard & GPIO interrupt */
+	it8801_muxed_kbd_gpio_intr_enable();
+
 	return EC_SUCCESS;
 }
 
@@ -354,15 +391,16 @@ static int it8801_ioex_set_flags_by_mask(int ioex, int port,
 	}
 
 	/* GPIO alternate function switching(GPIO[00, 12:15, 20:23]). */
-	it8801_ioex_write(ioex, IT8801_REG_GPIO_CR(port, mask),
+	rv = it8801_ioex_write(ioex, IT8801_REG_GPIO_CR(port, mask),
 					IT8801_REG_MASK_GPIOAFS_FUNC1);
+	if (rv)
+		return rv;
 
 	mutex_lock(&ioex_mutex);
 	rv = it8801_ioex_read(ioex, IT8801_REG_GPIO_CR(port, mask), &val);
-	if (rv) {
-		mutex_unlock(&ioex_mutex);
-		return rv;
-	}
+	if (rv)
+		goto unlock_mutex;
+
 	/* Select open drain 0:push-pull 1:open-drain */
 	if (flags & GPIO_OPEN_DRAIN)
 		val |= IT8801_GPIOIOT;
@@ -379,26 +417,113 @@ static int it8801_ioex_set_flags_by_mask(int ioex, int port,
 
 		rv = it8801_ioex_write(ioex, IT8801_REG_GPIO_SOVR(port),
 						it8801_gpio_sov[port]);
-		if (rv) {
-			mutex_unlock(&ioex_mutex);
-			return rv;
-		}
+		if (rv)
+			goto unlock_mutex;
+
 		val |= IT8801_GPIODIR;
-	} else
+	} else {
 		val &= ~IT8801_GPIODIR;
+	}
+
+	/* Set Interrupt Type */
+	if (flags & GPIO_INT_RISING)
+		val |= IT8801_GPIOIOT_INT_RISING;
+	if (flags & GPIO_INT_FALLING)
+		val |= IT8801_GPIOIOT_INT_FALLING;
 
 	rv = it8801_ioex_write(ioex, IT8801_REG_GPIO_CR(port, mask), val);
+
+unlock_mutex:
 	mutex_unlock(&ioex_mutex);
 
 	return rv;
 }
 
+/* Enable the individual GPIO interrupt pins based on the board requirement. */
+static int it8801_ioex_enable_interrupt(int ioex, int port, int mask,
+					int enable)
+{
+	int rv;
+
+	if (ioex_check_is_not_valid(port, mask))
+		return EC_ERROR_INVAL;
+
+	/* Clear pending interrupt */
+	rv = it8801_ioex_update(ioex, IT8801_REG_GPIO_ISR(port),
+				mask, MASK_SET);
+	if (rv)
+		return rv;
+
+	return it8801_ioex_update(ioex, IT8801_REG_GPIO_IER(port),
+				mask, enable ? MASK_SET : MASK_CLR);
+}
+
+static void it8801_ioex_irq(int ioex, int port)
+{
+	int rv, data, i;
+	const struct ioex_info *g;
+
+	rv = it8801_ioex_read(ioex, IT8801_REG_GPIO_ISR(port), &data);
+	if (rv || !data)
+		return;
+
+	/* Trigger the intended interrupt from the IOEX IRQ pins */
+	for (i = 0, g = ioex_list; i < ioex_ih_count; i++, g++) {
+		if (ioex == g->ioex && port == g->port && data & g->mask) {
+			ioex_irq_handlers[i](i + IOEX_SIGNAL_START);
+			data &= ~g->mask;
+
+			/* Clear pending interrupt */
+			it8801_ioex_update(ioex, IT8801_REG_GPIO_ISR(port),
+					g->mask, MASK_SET);
+
+			if (!data)
+				break;
+		}
+	}
+}
+
+static void it8801_ioex_event_handler(void)
+{
+	int data, i;
+
+	/* Gather KSI interrupt status register */
+	if (it8801_read(IT8801_REG_GISR, &data))
+		return;
+
+	/* Wake the keyboard scan task if KSI interrupts are triggered */
+	if (IS_ENABLED(CONFIG_KEYBOARD_NOT_RAW) &&
+		data & IT8801_REG_MASK_GISR_GKSIIS)
+		task_wake(TASK_ID_KEYSCAN);
+
+	/*
+	 * Trigger the GPIO callback functions if the GPIO interrupts are
+	 * triggered.
+	 */
+	if (data & (IT8801_REG_MASK_GISR_GGPIOGXIS)) {
+		for (i = 0; i < CONFIG_IO_EXPANDER_PORT_COUNT; i++) {
+			if (ioex_config[i].drv == &it8801_ioexpander_drv) {
+				/* Interrupt from GPIO port 0 is triggered */
+				if (data & IT8801_REG_MASK_GISR_GGPIOG0IS)
+					it8801_ioex_irq(i, 0);
+				/* Interrupt from GPIO port 1 is triggered */
+				if (data & IT8801_REG_MASK_GISR_GGPIOG1IS)
+					it8801_ioex_irq(i, 1);
+				/* Interrupt from GPIO port 2 is triggered */
+				if (data & IT8801_REG_MASK_GISR_GGPIOG2IS)
+					it8801_ioex_irq(i, 2);
+			}
+		}
+	}
+}
+
 const struct ioexpander_drv it8801_ioexpander_drv = {
 	.init              = &it8801_ioex_init,
 	.get_level         = &it8801_ioex_get_level,
 	.set_level         = &it8801_ioex_set_level,
 	.get_flags_by_mask = &it8801_ioex_get_flags_by_mask,
 	.set_flags_by_mask = &it8801_ioex_set_flags_by_mask,
+	.enable_interrupt  = &it8801_ioex_enable_interrupt,
 };
 
 static void dump_register(int reg)