ec/google: Use EC_HOST_EVENT_NONE

google_chromeec_get_event returns 0 for no event. Return
EC_HOST_EVENT_NONE=0 to improve readability.

BUG=b:184074997
TEST=Build and boot guybrush without error

Signed-off-by: Rob Barnes <robbarnes@google.com>
Change-Id: Ic08ed9ccdd7c0023d0fe8b641fcf60dca495a242
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55547
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/ec/google/chromeec/ec.h

@@ -19,7 +19,7 @@ uint64_t google_chromeec_get_wake_mask(void);
 int google_chromeec_set_sci_mask(uint64_t mask);
 int google_chromeec_set_smi_mask(uint64_t mask);
 int google_chromeec_set_wake_mask(uint64_t mask);
-uint8_t google_chromeec_get_event(void);
+enum host_event_code google_chromeec_get_event(void);
 
 /* Check if EC supports feature EC_FEATURE_UNIFIED_WAKE_MASKS */
 bool google_chromeec_is_uhepi_supported(void);

src/ec/google/chromeec/ec_i2c.c

@@ -239,8 +239,8 @@ int google_chromeec_command(struct chromeec_command *cec_command)
 
 #endif /* CONFIG_EC_GOOGLE_CHROMEEC_I2C_PROTO3 */
 
-u8 google_chromeec_get_event(void)
+enum host_event_code google_chromeec_get_event(void)
 {
 	printk(BIOS_ERR, "%s: Not supported.\n", __func__);
-	return 0;
+	return EC_HOST_EVENT_NONE;
 }

src/ec/google/chromeec/ec_lpc.c

@@ -461,11 +461,11 @@ static int google_chromeec_data_ready(u16 port)
 					    EC_LPC_CMDR_DATA);
 }
 
-u8 google_chromeec_get_event(void)
+enum host_event_code google_chromeec_get_event(void)
 {
 	if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) {
 		printk(BIOS_ERR, "Timeout waiting for EC ready!\n");
-		return 0;
+		return EC_HOST_EVENT_NONE;
 	}
 
 	/* Issue the ACPI query-event command */
@@ -473,12 +473,12 @@ u8 google_chromeec_get_event(void)
 
 	if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) {
 		printk(BIOS_ERR, "Timeout waiting for EC QUERY_EVENT!\n");
-		return 0;
+		return EC_HOST_EVENT_NONE;
 	}
 
 	if (google_chromeec_data_ready(EC_LPC_ADDR_ACPI_CMD)) {
 		printk(BIOS_ERR, "Timeout waiting for data ready!\n");
-		return 0;
+		return EC_HOST_EVENT_NONE;
 	}
 
 	/* Event (or 0 if none) is returned directly in the data byte */

src/ec/google/chromeec/ec_spi.c

@@ -100,8 +100,8 @@ int google_chromeec_command(struct chromeec_command *cec_command)
 	return crosec_command_proto(cec_command, crosec_spi_io, &slave);
 }
 
-u8 google_chromeec_get_event(void)
+enum host_event_code google_chromeec_get_event(void)
 {
 	printk(BIOS_ERR, "%s: Not supported.\n", __func__);
-	return 0;
+	return EC_HOST_EVENT_NONE;
 }

src/ec/google/chromeec/smihandler.c

@@ -37,7 +37,7 @@ static void clear_pending_events(void)
 {
 	struct ec_response_get_next_event mkbp_event;
 
-	while (google_chromeec_get_event() != 0)
+	while (google_chromeec_get_event() != EC_HOST_EVENT_NONE)
 		;
 
 	printk(BIOS_DEBUG, "Clearing pending EC events. Error code EC_RES_UNAVAILABLE(9) is expected.\n");