chromeos: Unconditionally clear the EC recovery request

Add the empty weak function clear_recovery_mode_switch().

Problem:
If GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC is set,
the following will happen:

1. Boot device in recovery mode with Esc + F3 + Pwr.
2. Turn device off with Pwr button.
3. Turn device on with Pwr button.

Device still boots to recovery screen with
recovery_reason:0x02 recovery button pressed.

If GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC isn't set, turning the
device off and on again  with the Pwr button does a normal boot.

Solution:
Unconditionally clear the recovery flag.

BUG=chromium:279607
BRANCH=TOT
TEST=Compile OK.

Original-Change-Id: Ie1e3251a6db12e75e385220e9d3791078393b1bf
Original-Signed-off-by: Sheng-Liang Song <ssl@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/197780
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-by: Randall Spangler <rspangler@chromium.org>
Original-Commit-Queue: Sheng-liang Song <ssl@google.com>
Original-Tested-by: Sheng-liang Song <ssl@google.com>
(cherry picked from commit 18908bb64cef34ca41812814817ef887961bed34)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I71ca9f3ea8d816c865375ec66a0603ca211f23ae
Reviewed-on: http://review.coreboot.org/7895
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins)

src/ec/google/chromeec/ec.c

@@ -93,11 +93,35 @@ static u32 google_chromeec_get_mask(u8 type)
 	return 0;
 }
 
+static int google_chromeec_set_mask(u8 type, u32 mask)
+{
+	struct ec_params_host_event_mask req;
+	struct ec_response_host_event_mask rsp;
+	struct chromeec_command cmd;
+
+	req.mask = mask;
+	cmd.cmd_code = type;
+	cmd.cmd_version = 0;
+	cmd.cmd_data_in = &req;
+	cmd.cmd_size_in = sizeof(req);
+	cmd.cmd_data_out = &rsp;
+	cmd.cmd_size_out = sizeof(rsp);
+
+	return google_chromeec_command(&cmd);
+}
+
 u32 google_chromeec_get_events_b(void)
 {
 	return google_chromeec_get_mask(EC_CMD_HOST_EVENT_GET_B);
 }
 
+int google_chromeec_clear_events_b(u32 mask)
+{
+	printk(BIOS_DEBUG, "Chrome EC: clear events_b mask to 0x%08x\n", mask);
+	return google_chromeec_set_mask(
+		EC_CMD_HOST_EVENT_CLEAR_B, mask);
+}
+
 #ifndef __SMM__
 void google_chromeec_check_ec_image(int expected_type)
 {
@@ -278,23 +302,6 @@ int google_chromeec_i2c_xfer(uint8_t chip, uint8_t addr, int alen,
 	return 0;
 }
 
-static int google_chromeec_set_mask(u8 type, u32 mask)
-{
-	struct ec_params_host_event_mask req;
-	struct ec_response_host_event_mask rsp;
-	struct chromeec_command cmd;
-
-	req.mask = mask;
-	cmd.cmd_code = type;
-	cmd.cmd_version = 0;
-	cmd.cmd_data_in = &req;
-	cmd.cmd_size_in = sizeof(req);
-	cmd.cmd_data_out = &rsp;
-	cmd.cmd_size_out = sizeof(rsp);
-
-	return google_chromeec_command(&cmd);
-}
-
 int google_chromeec_set_sci_mask(u32 mask)
 {
 	printk(BIOS_DEBUG, "Chrome EC: Set SCI mask to 0x%08x\n", mask);

src/ec/google/chromeec/ec.h

@@ -43,6 +43,7 @@ void google_chromeec_check_ec_image(int expected_type);
 uint8_t google_chromeec_calc_checksum(const uint8_t *data, int size);
 u16 google_chromeec_get_board_version(void);
 u32 google_chromeec_get_events_b(void);
+int google_chromeec_clear_events_b(u32 mask);
 int google_chromeec_kbbacklight(int percent);
 void google_chromeec_post(u8 postcode);
 void google_chromeec_log_events(u32 mask);

src/include/bootmode.h

@@ -25,6 +25,8 @@ void init_bootmode_straps(void);
 int get_write_protect_state(void);
 int get_developer_mode_switch(void);
 int get_recovery_mode_switch(void);
+int clear_recovery_mode_switch(void);
+
 
 int gfx_get_init_done(void);
 void gfx_set_init_done(int done);

src/vendorcode/google/chromeos/vboot_handoff.c

@@ -54,6 +54,12 @@ int vboot_enable_recovery(void)
 	return !!(vbho->init_params.out_flags & VB_INIT_OUT_ENABLE_RECOVERY);
 }
 
+int __attribute__((weak)) clear_recovery_mode_switch(void)
+{
+	// Can be implemented by a mainboard
+	return 0;
+}
+
 int vboot_skip_display_init(void)
 {
 	struct vboot_handoff *vbho;

src/vendorcode/google/chromeos/vboot_loader.c

@@ -245,8 +245,10 @@ static void vboot_invoke_wrapper(struct vboot_handoff *vboot_handoff)
 	iflags = &vboot_handoff->init_params.flags;
 	if (get_developer_mode_switch())
 		*iflags |= VB_INIT_FLAG_DEV_SWITCH_ON;
-	if (get_recovery_mode_switch())
+	if (get_recovery_mode_switch()) {
+		clear_recovery_mode_switch();
 		*iflags |= VB_INIT_FLAG_REC_BUTTON_PRESSED;
+	}
 	if (get_write_protect_state())
 		*iflags |= VB_INIT_FLAG_WP_ENABLED;
 	if (vboot_get_sw_write_protect())