common/cmd_fastboot.c

/*
 * Copyright 2008 - 2009 Windriver, <www.windriver.com>
 * Author: Tom Rix <Tom.Rix@windriver.com>
 *
 * (C) Copyright 2014 Linaro, Ltd.
 * Rob Herring <robh@kernel.org>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */
#include <common.h>
#include <command.h>
#include <fb_fastboot.h>
#include <g_dnl.h>

// Fastboot main loop.
//
// |host_connect_timeout_ms|: timeout in milliseconds. If no host USB connection
// has been made in this time, exit fastboot mode. Set to 0 to disable timeout.
//
// Returns CMD_RET_SUCCESS on exit whether timeout occurred or not.
static int fastboot_loop(int host_connect_timeout_ms)
{
	int ret;

	g_dnl_clear_detach();
	ret = g_dnl_register("usb_dnl_fastboot");
	if (ret)
		return ret;

	uint64_t start_ticks = get_ticks();
	uint64_t wait_ticks = host_connect_timeout_ms * (get_tbclk() / 1000);

	while (1) {
		if (g_dnl_detach())
			break;
		if (ctrlc())
			break;
		usb_gadget_handle_interrupts();

		if (host_connect_timeout_ms && !fastboot_host_connected &&
		    (get_ticks() - start_ticks) > wait_ticks) {
			printf("Host USB connection not detected, exiting fastboot\n");
			break;
		}
	}

	g_dnl_unregister();
	g_dnl_clear_detach();
	return CMD_RET_SUCCESS;
}

static int do_fastboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
{
	return fastboot_loop(0);
}

static int do_fastboot_if_host_connected(cmd_tbl_t *cmdtp, int flag, int argc,
					 char *const argv[])
{
	// Experimentally, 500ms seems too short and will sometimes exit before the
	// USB connection initializes, but 1s seems to work consistently on Linux. We
	// set it to 2s here just to be extra safe so it works for all hosts - the delay
	// only takes effect if fastboot was requested but no USB cable is connected,
	// so it's OK to overshoot here.
	return fastboot_loop(2000);
}

U_BOOT_CMD(fastboot, 1, 0, do_fastboot, "use USB Fastboot protocol",
	   "\n"
	   "    - run as a fastboot usb device");

// We give this a separate command rather than making timeout a parameter
// because we should decide a common timeout value here rather than passing
// it in, and to make the call site less ambiguous since newer versions of
// u-boot pass in the USB interface number as a param to `fastboot`.
U_BOOT_CMD(
	fastboot_if_host_connected, 1, 0, do_fastboot_if_host_connected,
	"use USB Fastboot protocol if a USB host is connected",
	"\n"
	"    - run as a fastboot usb device but exit if a host isn't detected");

__attribute__((weak)) bool force_fastboot_mode(void);
/*
 * Checks whether forced switching into fastboot mode is requested
 * Returns 0 if requested, 1 - otherwise.
 */
static int do_force_fastboot_mode(cmd_tbl_t *cmdtp, int flag, int argc,
				  char *const argv[])
{
	if (force_fastboot_mode) {
		if (force_fastboot_mode()) {
			printf("Force Fastboot mode: on\n");
			return 0;
		}
		printf("Force Fastboot mode: off\n");
	} else {
		printf("Force Fastboot mode is not supported.\n");
	}

	return 1;
}

U_BOOT_CMD(force_fastboot_mode, 1, 0, do_force_fastboot_mode,
	   "check if USB Fastboot mode should be forced", "");