chromeec: Add google_chromeec_pd_get_amode

The google_chromeec_pd_get_amode API checks whether TCPM is in a
specified alternate mode or not.

BUG=b:72387533
BRANCH=none
TEST=See 23746 "mb/google/fizz: Wait until display is ready"

Change-Id: Ib9b4ad06b61326fa167c77758603e038d817f928
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://review.coreboot.org/23744
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/ec/google/chromeec/ec.c

@@ -936,3 +936,51 @@ int google_ec_running_ro(void)
 #endif /* ! __SMM__ */
 
 #endif /* ! __PRE_RAM__ */
+
+/**
+ * Check if EC/TCPM is in an alternate mode or not.
+ *
+ * @param svid SVID of the alternate mode to check
+ * @return     0: Not in the mode. -1: Error. 1: Yes.
+ */
+int google_chromeec_pd_get_amode(uint16_t svid)
+{
+	struct ec_response_usb_pd_ports r;
+	struct chromeec_command cmd;
+	int i;
+
+	cmd.cmd_code = EC_CMD_USB_PD_PORTS;
+	cmd.cmd_version = 0;
+	cmd.cmd_data_in = NULL;
+	cmd.cmd_size_in = 0;
+	cmd.cmd_data_out = &r;
+	cmd.cmd_size_out = sizeof(r);
+	cmd.cmd_dev_index = 0;
+	if (google_chromeec_command(&cmd) < 0)
+		return -1;
+
+	for (i = 0; i < r.num_ports; i++) {
+		struct ec_params_usb_pd_get_mode_request p;
+		struct ec_params_usb_pd_get_mode_response res;
+
+		p.port = i;
+		p.svid_idx = 0;
+		cmd.cmd_code = EC_CMD_USB_PD_GET_AMODE;
+		cmd.cmd_version = 0;
+		cmd.cmd_data_in = &p;
+		cmd.cmd_size_in = sizeof(p);
+		cmd.cmd_data_out = &res;
+		cmd.cmd_size_out = sizeof(res);
+		cmd.cmd_dev_index = 0;
+
+		do {
+			if (google_chromeec_command(&cmd) < 0)
+				return -1;
+			if (res.svid == svid)
+				return 1;
+			p.svid_idx++;
+		} while (res.svid);
+	}
+
+	return 0;
+}

src/ec/google/chromeec/ec.h

@@ -36,6 +36,7 @@ u8 google_chromeec_get_event(void);
 bool google_chromeec_is_uhepi_supported(void);
 int google_ec_running_ro(void);
 void google_chromeec_init(void);
+int google_chromeec_pd_get_amode(uint16_t svid);
 
 /* Device events */
 uint64_t google_chromeec_get_device_enabled_events(void);