/*
 * (C) Copyright 2008 - 2009
 * Windriver, <www.windriver.com>
 * Tom Rix <Tom.Rix@windriver.com>
 *
 * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 *
 * Copyright 2014 Linaro, Ltd.
 * Rob Herring <robh@kernel.org>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */
#include <common.h>
#include <errno.h>
#include <malloc.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/composite.h>
#include <linux/compiler.h>
#include <version.h>
#include <g_dnl.h>

#define FASTBOOT_VERSION		"0.4"

#define FASTBOOT_INTERFACE_CLASS	0xff
#define FASTBOOT_INTERFACE_SUB_CLASS	0x42
#define FASTBOOT_INTERFACE_PROTOCOL	0x03

#define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0  (0x0200)
#define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1  (0x0040)
#define TX_ENDPOINT_MAXIMUM_PACKET_SIZE      (0x0040)

/* The 64 defined bytes plus \0 */
#define RESPONSE_LEN	(64 + 1)

#define EP_BUFFER_SIZE			4096

struct f_fastboot {
	struct usb_function usb_function;

	/* IN/OUT EP's and correspoinding requests */
	struct usb_ep *in_ep, *out_ep;
	struct usb_request *in_req, *out_req;
};

static inline struct f_fastboot *func_to_fastboot(struct usb_function *f)
{
	return container_of(f, struct f_fastboot, usb_function);
}

static struct f_fastboot *fastboot_func;
static unsigned int download_size;
static unsigned int download_bytes;

static struct usb_endpoint_descriptor fs_ep_in = {
	.bLength            = USB_DT_ENDPOINT_SIZE,
	.bDescriptorType    = USB_DT_ENDPOINT,
	.bEndpointAddress   = USB_DIR_IN,
	.bmAttributes       = USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize     = TX_ENDPOINT_MAXIMUM_PACKET_SIZE,
	.bInterval          = 0x00,
};

static struct usb_endpoint_descriptor fs_ep_out = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_OUT,
	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize		= RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1,
	.bInterval		= 0x00,
};

static struct usb_endpoint_descriptor hs_ep_out = {
	.bLength		= USB_DT_ENDPOINT_SIZE,
	.bDescriptorType	= USB_DT_ENDPOINT,
	.bEndpointAddress	= USB_DIR_OUT,
	.bmAttributes		= USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize		= RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0,
	.bInterval		= 0x00,
};

static struct usb_interface_descriptor interface_desc = {
	.bLength		= USB_DT_INTERFACE_SIZE,
	.bDescriptorType	= USB_DT_INTERFACE,
	.bInterfaceNumber	= 0x00,
	.bAlternateSetting	= 0x00,
	.bNumEndpoints		= 0x02,
	.bInterfaceClass	= FASTBOOT_INTERFACE_CLASS,
	.bInterfaceSubClass	= FASTBOOT_INTERFACE_SUB_CLASS,
	.bInterfaceProtocol	= FASTBOOT_INTERFACE_PROTOCOL,
};

static struct usb_descriptor_header *fb_runtime_descs[] = {
	(struct usb_descriptor_header *)&interface_desc,
	(struct usb_descriptor_header *)&fs_ep_in,
	(struct usb_descriptor_header *)&hs_ep_out,
	NULL,
};

/*
 * static strings, in UTF-8
 */
static const char fastboot_name[] = "Android Fastboot";

static struct usb_string fastboot_string_defs[] = {
	[0].s = fastboot_name,
	{  }			/* end of list */
};

static struct usb_gadget_strings stringtab_fastboot = {
	.language	= 0x0409,	/* en-us */
	.strings	= fastboot_string_defs,
};

static struct usb_gadget_strings *fastboot_strings[] = {
	&stringtab_fastboot,
	NULL,
};

static void rx_handler_command(struct usb_ep *ep, struct usb_request *req);

static void fastboot_complete(struct usb_ep *ep, struct usb_request *req)
{
	int status = req->status;
	if (!status)
		return;
	printf("status: %d ep '%s' trans: %d\n", status, ep->name, req->actual);
}

static int fastboot_bind(struct usb_configuration *c, struct usb_function *f)
{
	int id;
	struct usb_gadget *gadget = c->cdev->gadget;
	struct f_fastboot *f_fb = func_to_fastboot(f);

	/* DYNAMIC interface numbers assignments */
	id = usb_interface_id(c, f);
	if (id < 0)
		return id;
	interface_desc.bInterfaceNumber = id;

	id = usb_string_id(c->cdev);
	if (id < 0)
		return id;
	fastboot_string_defs[0].id = id;
	interface_desc.iInterface = id;

	f_fb->in_ep = usb_ep_autoconfig(gadget, &fs_ep_in);
	if (!f_fb->in_ep)
		return -ENODEV;
	f_fb->in_ep->driver_data = c->cdev;

	f_fb->out_ep = usb_ep_autoconfig(gadget, &fs_ep_out);
	if (!f_fb->out_ep)
		return -ENODEV;
	f_fb->out_ep->driver_data = c->cdev;

	hs_ep_out.bEndpointAddress = fs_ep_out.bEndpointAddress;

	return 0;
}

static void fastboot_unbind(struct usb_configuration *c, struct usb_function *f)
{
	memset(fastboot_func, 0, sizeof(*fastboot_func));
}

static void fastboot_disable(struct usb_function *f)
{
	struct f_fastboot *f_fb = func_to_fastboot(f);

	usb_ep_disable(f_fb->out_ep);
	usb_ep_disable(f_fb->in_ep);

	if (f_fb->out_req) {
		free(f_fb->out_req->buf);
		usb_ep_free_request(f_fb->out_ep, f_fb->out_req);
		f_fb->out_req = NULL;
	}
	if (f_fb->in_req) {
		free(f_fb->in_req->buf);
		usb_ep_free_request(f_fb->in_ep, f_fb->in_req);
		f_fb->in_req = NULL;
	}
}

static struct usb_request *fastboot_start_ep(struct usb_ep *ep)
{
	struct usb_request *req;

	req = usb_ep_alloc_request(ep, 0);
	if (!req)
		return NULL;

	req->length = EP_BUFFER_SIZE;
	req->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, EP_BUFFER_SIZE);
	if (!req->buf) {
		usb_ep_free_request(ep, req);
		return NULL;
	}

	memset(req->buf, 0, req->length);
	return req;
}

static int fastboot_set_alt(struct usb_function *f,
			    unsigned interface, unsigned alt)
{
	int ret;
	struct usb_composite_dev *cdev = f->config->cdev;
	struct usb_gadget *gadget = cdev->gadget;
	struct f_fastboot *f_fb = func_to_fastboot(f);

	debug("%s: func: %s intf: %d alt: %d\n",
	      __func__, f->name, interface, alt);

	/* make sure we don't enable the ep twice */
	if (gadget->speed == USB_SPEED_HIGH)
		ret = usb_ep_enable(f_fb->out_ep, &hs_ep_out);
	else
		ret = usb_ep_enable(f_fb->out_ep, &fs_ep_out);
	if (ret) {
		puts("failed to enable out ep\n");
		return ret;
	}

	f_fb->out_req = fastboot_start_ep(f_fb->out_ep);
	if (!f_fb->out_req) {
		puts("failed to alloc out req\n");
		ret = -EINVAL;
		goto err;
	}
	f_fb->out_req->complete = rx_handler_command;

	ret = usb_ep_enable(f_fb->in_ep, &fs_ep_in);
	if (ret) {
		puts("failed to enable in ep\n");
		goto err;
	}

	f_fb->in_req = fastboot_start_ep(f_fb->in_ep);
	if (!f_fb->in_req) {
		puts("failed alloc req in\n");
		ret = -EINVAL;
		goto err;
	}
	f_fb->in_req->complete = fastboot_complete;

	ret = usb_ep_queue(f_fb->out_ep, f_fb->out_req, 0);
	if (ret)
		goto err;

	return 0;
err:
	fastboot_disable(f);
	return ret;
}

static int fastboot_add(struct usb_configuration *c)
{
	struct f_fastboot *f_fb = fastboot_func;
	int status;

	debug("%s: cdev: 0x%p\n", __func__, c->cdev);

	if (!f_fb) {
		f_fb = memalign(CONFIG_SYS_CACHELINE_SIZE, sizeof(*f_fb));
		if (!f_fb)
			return -ENOMEM;

		fastboot_func = f_fb;
		memset(f_fb, 0, sizeof(*f_fb));
	}

	f_fb->usb_function.name = "f_fastboot";
	f_fb->usb_function.hs_descriptors = fb_runtime_descs;
	f_fb->usb_function.bind = fastboot_bind;
	f_fb->usb_function.unbind = fastboot_unbind;
	f_fb->usb_function.set_alt = fastboot_set_alt;
	f_fb->usb_function.disable = fastboot_disable;
	f_fb->usb_function.strings = fastboot_strings;

	status = usb_add_function(c, &f_fb->usb_function);
	if (status) {
		free(f_fb);
		fastboot_func = f_fb;
	}

	return status;
}
DECLARE_GADGET_BIND_CALLBACK(usb_dnl_fastboot, fastboot_add);

int fastboot_tx_write(const char *buffer, unsigned int buffer_size)
{
	struct usb_request *in_req = fastboot_func->in_req;
	int ret;

	memcpy(in_req->buf, buffer, buffer_size);
	in_req->length = buffer_size;
	ret = usb_ep_queue(fastboot_func->in_ep, in_req, 0);
	if (ret)
		printf("Error %d on queue\n", ret);
	return 0;
}

static int fastboot_tx_write_str(const char *buffer)
{
	return fastboot_tx_write(buffer, strlen(buffer));
}

static void compl_do_reset(struct usb_ep *ep, struct usb_request *req)
{
	do_reset(NULL, 0, 0, NULL);
}

static void cb_reboot(struct usb_ep *ep, struct usb_request *req)
{
	fastboot_func->in_req->complete = compl_do_reset;
	fastboot_tx_write_str("OKAY");
}

static int strcmp_l1(const char *s1, const char *s2)
{
	if (!s1 || !s2)
		return -1;
	return strncmp(s1, s2, strlen(s1));
}

static void cb_getvar(struct usb_ep *ep, struct usb_request *req)
{
	char *cmd = req->buf;
	char response[RESPONSE_LEN];
	const char *s;
	size_t chars_left;

	strcpy(response, "OKAY");
	chars_left = sizeof(response) - strlen(response) - 1;

	strsep(&cmd, ":");
	if (!cmd) {
		fastboot_tx_write_str("FAILmissing var");
		return;
	}

	if (!strcmp_l1("version", cmd)) {
		strncat(response, FASTBOOT_VERSION, chars_left);
	} else if (!strcmp_l1("bootloader-version", cmd)) {
		strncat(response, U_BOOT_VERSION, chars_left);
	} else if (!strcmp_l1("downloadsize", cmd)) {
		char str_num[12];

		sprintf(str_num, "%08x", CONFIG_USB_FASTBOOT_BUF_SIZE);
		strncat(response, str_num, chars_left);
	} else if (!strcmp_l1("serialno", cmd)) {
		s = getenv("serial#");
		if (s)
			strncat(response, s, chars_left);
		else
			strcpy(response, "FAILValue not set");
	} else {
		strcpy(response, "FAILVariable not implemented");
	}
	fastboot_tx_write_str(response);
}

static unsigned int rx_bytes_expected(void)
{
	int rx_remain = download_size - download_bytes;
	if (rx_remain < 0)
		return 0;
	if (rx_remain > EP_BUFFER_SIZE)
		return EP_BUFFER_SIZE;
	return rx_remain;
}

#define BYTES_PER_DOT	0x20000
static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
{
	char response[RESPONSE_LEN];
	unsigned int transfer_size = download_size - download_bytes;
	const unsigned char *buffer = req->buf;
	unsigned int buffer_size = req->actual;

	if (req->status != 0) {
		printf("Bad status: %d\n", req->status);
		return;
	}

	if (buffer_size < transfer_size)
		transfer_size = buffer_size;

	memcpy((void *)CONFIG_USB_FASTBOOT_BUF_ADDR + download_bytes,
	       buffer, transfer_size);

	download_bytes += transfer_size;

	/* Check if transfer is done */
	if (download_bytes >= download_size) {
		/*
		 * Reset global transfer variable, keep download_bytes because
		 * it will be used in the next possible flashing command
		 */
		download_size = 0;
		req->complete = rx_handler_command;
		req->length = EP_BUFFER_SIZE;

		sprintf(response, "OKAY");
		fastboot_tx_write_str(response);

		printf("\ndownloading of %d bytes finished\n", download_bytes);
	} else {
		req->length = rx_bytes_expected();
		if (req->length < ep->maxpacket)
			req->length = ep->maxpacket;
	}

	if (download_bytes && !(download_bytes % BYTES_PER_DOT)) {
		putc('.');
		if (!(download_bytes % (74 * BYTES_PER_DOT)))
			putc('\n');
	}
	req->actual = 0;
	usb_ep_queue(ep, req, 0);
}

static void cb_download(struct usb_ep *ep, struct usb_request *req)
{
	char *cmd = req->buf;
	char response[RESPONSE_LEN];

	strsep(&cmd, ":");
	download_size = simple_strtoul(cmd, NULL, 16);
	download_bytes = 0;

	printf("Starting download of %d bytes\n", download_size);

	if (0 == download_size) {
		sprintf(response, "FAILdata invalid size");
	} else if (download_size > CONFIG_USB_FASTBOOT_BUF_SIZE) {
		download_size = 0;
		sprintf(response, "FAILdata too large");
	} else {
		sprintf(response, "DATA%08x", download_size);
		req->complete = rx_handler_dl_image;
		req->length = rx_bytes_expected();
		if (req->length < ep->maxpacket)
			req->length = ep->maxpacket;
	}
	fastboot_tx_write_str(response);
}

static void do_bootm_on_complete(struct usb_ep *ep, struct usb_request *req)
{
	char boot_addr_start[12];
	char *bootm_args[] = { "bootm", boot_addr_start, NULL };

	puts("Booting kernel..\n");

	sprintf(boot_addr_start, "0x%lx", load_addr);
	do_bootm(NULL, 0, 2, bootm_args);

	/* This only happens if image is somehow faulty so we start over */
	do_reset(NULL, 0, 0, NULL);
}

static void cb_boot(struct usb_ep *ep, struct usb_request *req)
{
	fastboot_func->in_req->complete = do_bootm_on_complete;
	fastboot_tx_write_str("OKAY");
}

struct cmd_dispatch_info {
	char *cmd;
	void (*cb)(struct usb_ep *ep, struct usb_request *req);
};

static const struct cmd_dispatch_info cmd_dispatch_info[] = {
	{
		.cmd = "reboot",
		.cb = cb_reboot,
	}, {
		.cmd = "getvar:",
		.cb = cb_getvar,
	}, {
		.cmd = "download:",
		.cb = cb_download,
	}, {
		.cmd = "boot",
		.cb = cb_boot,
	},
};

static void rx_handler_command(struct usb_ep *ep, struct usb_request *req)
{
	char *cmdbuf = req->buf;
	void (*func_cb)(struct usb_ep *ep, struct usb_request *req) = NULL;
	int i;

	for (i = 0; i < ARRAY_SIZE(cmd_dispatch_info); i++) {
		if (!strcmp_l1(cmd_dispatch_info[i].cmd, cmdbuf)) {
			func_cb = cmd_dispatch_info[i].cb;
			break;
		}
	}

	if (!func_cb)
		fastboot_tx_write_str("FAILunknown command");
	else
		func_cb(ep, req);

	if (req->status == 0) {
		*cmdbuf = '\0';
		req->actual = 0;
		usb_ep_queue(ep, req, 0);
	}
}