retimer: support retimer firmware update

To support AP to update firmware during boot up, one byte EC RAM is
allocated for AP <-> EC communication. AP queries PD port/requests EC
to perform operations via EC_CMD_ACPI_WRITE; and fetches result from EC
via EC_CMD_ACPI_READ.

The flow is:
1. AP queries EC PD ports which port supports retimer firmware update.
2. AP queries current MUX.
3. a) If no device attached, AP requests EC to suspend PD task of the
   port. Then AP requests EC to set MUX to USB mode,
   Safe mode, TBT mode. After entering TBT mode, the OS can either
   enumerate the retimers or do firmware update on the enumerated
   retimers. Once done, AP requests EC to disconnect MUX and resume PD
   task.
3. b) If device attached, AP moves on as usual. Retimer firmware update
   is not performed.

BUG=b:162528867
BRANCH=none
TEST=Tested NDA case on Voxel board, together with coreboot and kernel
changes. Coreboot changes are merged. Kernel patches list is:
https://chromium-review.googlesource.com/c/chromiumos/
third_party/kernel/+/2670719

After power up, host scans retimers, in sysfs
localhost ~ # ls /sys/bus/thunderbolt/devices/
0-0  0-0:1.1  0-0:3.1 domain0
On PD port 1, manually update retimer firmware. Copy firmware to
nvm_non_active1/nvmem, then authenticate it. Host starts flow to update
firmware.
After it's done, PD port 1 resumes. Hotplug DP dongle/TBT device, devices
should function fully.
TEST=Tested DA cases on Voxel board, together with coreboot and kernel
changes. USB4/TBT devices function as usual.

Signed-off-by: li feng <li1.feng@intel.com>
Change-Id: Ie976e75f892d5caf48a948598a058a4f42e07eb3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2594492
Reviewed-by: Keith Short <keithshort@chromium.org>

1 files changed, 159 insertions, 0 deletions

diff --git a/common/usbc/usb_retimer_fw_update.c b/common/usbc/usb_retimer_fw_update.c
new file mode 100644
index 0000000000..7ae833b8c9
--- /dev/null
+++ b/common/usbc/usb_retimer_fw_update.c
@@ -0,0 +1,159 @@
+/* Copyright 2021 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "atomic.h"
+#include <stdbool.h>
+#include <stdint.h>
+#include "compile_time_macros.h"
+#include "console.h"
+#include "hooks.h"
+#include "timer.h"
+#include "usb_common.h"
+#include "usb_mux.h"
+#include "usb_tc_sm.h"
+
+#ifdef CONFIG_COMMON_RUNTIME
+#define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)
+#define CPRINTF(format, args...) cprintf(CC_USBPD, format, ## args)
+#else
+#define CPRINTS(format, args...)
+#define CPRINTF(format, args...)
+#endif
+
+/*
+ * Retimer firmware update is initiated by AP.
+ * The operations requested by AP are:
+ * 0 - USB_RETIMER_FW_UPDATE_QUERY_PORT
+ * 1 - USB_RETIMER_FW_UPDATE_SUSPEND_PD
+ * 2 - USB_RETIMER_FW_UPDATE_RESUME_PD
+ * 3 - USB_RETIMER_FW_UPDATE_GET_MUX
+ * 4 - USB_RETIMER_FW_UPDATE_SET_USB
+ * 5 - USB_RETIMER_FW_UPDATE_SET_SAFE
+ * 6 - USB_RETIMER_FW_UPDATE_SET_TBT
+ * 7 - USB_RETIMER_FW_UPDATE_DISCONNECT
+ *
+ * Operation 0 is processed immediately.
+ * Operations 1 to 7 are deferred and processed inside tc_run().
+ * Operations 1/2/3 can be processed any time; while 4/5/6/7 have
+ * to be processed when PD task is suspended.
+ * Two TC flags are created for this situation.
+ * If Op 1/2/3 is received, TC_FLAGS_USB_RETIMER_FW_UPDATE_RUN
+ * is set, PD task will be waken up and process it.
+ * If 4/5/6/7 is received, TC_FLAGS_USB_RETIMER_FW_UPDATE_LTD_RUN is
+ * set, PD task should be in suspended mode and process it.
+ *
+ */
+
+/* Track current port AP requested to update retimer firmware */
+static int cur_port;
+static int last_op; /* Operation received from AP via ACPI_WRITE */
+/* MUX value returned to ACPI_READ */
+static int last_mux_result = USB_RETIMER_FW_UPDATE_INVALID_MUX;
+
+__overridable int usb_retimer_fw_update_query_port(void)
+{
+	return 0;
+}
+
+int usb_retimer_fw_update_get_result(void)
+{
+	int result = 0;
+
+	switch (last_op) {
+	case USB_RETIMER_FW_UPDATE_SUSPEND_PD:
+	case USB_RETIMER_FW_UPDATE_RESUME_PD:
+		result = pd_is_port_enabled(cur_port);
+		break;
+	case USB_RETIMER_FW_UPDATE_QUERY_PORT:
+		result = usb_retimer_fw_update_query_port();
+		break;
+	case USB_RETIMER_FW_UPDATE_GET_MUX:
+	case USB_RETIMER_FW_UPDATE_SET_USB:
+	case USB_RETIMER_FW_UPDATE_SET_SAFE:
+	case USB_RETIMER_FW_UPDATE_SET_TBT:
+	case USB_RETIMER_FW_UPDATE_DISCONNECT:
+		result = last_mux_result;
+		break;
+	default:
+		break;
+	}
+
+	return result;
+}
+
+void usb_retimer_fw_update_process_op_cb(int port)
+{
+	switch (last_op) {
+	case USB_RETIMER_FW_UPDATE_SUSPEND_PD:
+		pd_set_suspend(port, 1);
+		break;
+	case USB_RETIMER_FW_UPDATE_RESUME_PD:
+		pd_set_suspend(port, 0);
+		break;
+	case USB_RETIMER_FW_UPDATE_GET_MUX:
+		last_mux_result = usb_mux_get(port);
+		break;
+	case USB_RETIMER_FW_UPDATE_SET_USB:
+		usb_mux_set(port, USB_PD_MUX_USB_ENABLED,
+			USB_SWITCH_CONNECT, pd_get_polarity(port));
+		last_mux_result = usb_mux_get(port);
+		break;
+	case USB_RETIMER_FW_UPDATE_SET_SAFE:
+		usb_mux_set_safe_mode(port);
+		last_mux_result = usb_mux_get(port);
+		break;
+	case USB_RETIMER_FW_UPDATE_SET_TBT:
+		usb_mux_set(port, USB_PD_MUX_TBT_COMPAT_ENABLED,
+			USB_SWITCH_CONNECT, pd_get_polarity(port));
+		last_mux_result = usb_mux_get(port);
+		break;
+	case USB_RETIMER_FW_UPDATE_DISCONNECT:
+		usb_mux_set(port, USB_PD_MUX_NONE,
+			USB_SWITCH_DISCONNECT, pd_get_polarity(port));
+		last_mux_result = usb_mux_get(port);
+		break;
+	default:
+		break;
+	}
+}
+
+void usb_retimer_fw_update_process_op(int port, int op)
+{
+	ASSERT(port >= 0 && port < CONFIG_USB_PD_PORT_MAX_COUNT);
+
+	/*
+	 * TODO(b/179220036): check not overlapping requests;
+	 * not change cur_port if retimer scan is in progress
+	 */
+	last_op = op;
+
+	switch (op) {
+	case USB_RETIMER_FW_UPDATE_QUERY_PORT:
+		break;
+	/* Operations can't be processed in ISR, defer to later */
+	case USB_RETIMER_FW_UPDATE_GET_MUX:
+		last_mux_result = USB_RETIMER_FW_UPDATE_INVALID_MUX;
+		tc_usb_firmware_fw_update_run(port);
+		break;
+	case USB_RETIMER_FW_UPDATE_SUSPEND_PD:
+	case USB_RETIMER_FW_UPDATE_RESUME_PD:
+		cur_port = port;
+		tc_usb_firmware_fw_update_run(port);
+		break;
+	case USB_RETIMER_FW_UPDATE_SET_USB:
+	case USB_RETIMER_FW_UPDATE_SET_SAFE:
+	case USB_RETIMER_FW_UPDATE_SET_TBT:
+	case USB_RETIMER_FW_UPDATE_DISCONNECT:
+		if (pd_is_port_enabled(port)) {
+			last_mux_result = USB_RETIMER_FW_UPDATE_ERR;
+		} else {
+			last_mux_result = USB_RETIMER_FW_UPDATE_INVALID_MUX;
+			tc_usb_firmware_fw_update_limited_run(port);
+		}
+		break;
+	default:
+		break;
+	}
+}