dfu.c

/*
 * This file is part of the stfuboot project.
 *
 * Copyright (C) 2012 Innovative Converged Devices (ICD)
 *
 * Author(s):
 *          Andrey Smirnov <andrey.smirnov@convergeddevices.net>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <string.h>
#include <stdbool.h>

#include <libopencm3/stm32/f1/flash.h>
#include <libopencm3/usb/usbd.h>

#include "dfu.h"

#define MIN(a, b) ((a)<(b) ? (a) : (b))

struct stfub_memory_bank {
	u32 start, end;
};

static const struct stfub_memory_bank stfub_memory_banks[] = {
	[STFUB_AS_MAIN_MEMORY] = {
		.start	= 0x08004800,
		.end	= 0x08040000,
	},
	[STFUB_AS_SYSTEM_MEMORY] = {
		.start	= 0x08000000,
		.end	= 0x08004800,
	},
	[STFUB_AS_OPTION_BYTES] = {
		.start	= 0x1FFFF800,
		.end	= 0x1FFFF810,
	},
};

struct stfub_dfu {
	const struct usb_dfu_descriptor *descr;

	u32 timeout;

	enum dfu_status status;
	enum dfu_state  state;

	struct {
		const u8 *readptr;
		u8 *writeptr;
	} block;

	const struct stfub_memory_bank *bank;

	struct {
		int block_no;
		int block_len;
		u8 block[2048];
	} pending;
};

static struct stfub_dfu dfu;

void stfub_dfu_init(const struct usb_dfu_descriptor *descr)
{
	dfu.state	= STATE_DFU_IDLE;
	dfu.status	= DFU_STATUS_OK;
	dfu.descr	= descr;
	dfu.timeout	= 100;
	dfu.bank	= &stfub_memory_banks[STFUB_AS_MAIN_MEMORY];
	dfu.pending.block_len = -1;
}

void stfub_dfu_switch_altsetting(usbd_device *usbd_dev, u16 interface, u16 altsetting)
{
	dfu.bank = &stfub_memory_banks[altsetting];
}

static int stfub_dfu_read_firmware_block(struct stfub_dfu *dfu, u16 block_no,
					 u8 *buf, int len)
{
	int read_len;
	const u8 *start_address  = (const u8 *)dfu->bank->start;
	const u8 *end_address    = (const u8 *)dfu->bank->end;

	if (block_no == 0)
		dfu->block.readptr = start_address;

	read_len = MIN(len, end_address - dfu->block.readptr);

	memcpy(buf, dfu->block.readptr, read_len);

	dfu->block.readptr += read_len;

	return read_len;
}

static int stfub_dfu_write_firmware_block(struct stfub_dfu *dfu)
{
	stfub_printf("stfub_dfu_write_firmware_block\n");

	if (dfu->bank == &stfub_memory_banks[STFUB_AS_OPTION_BYTES]) {
		/* Option bytes are a special case, handle them separately */
		return -1;
	} else {
		int write_len, i;

		u8 *start_address  = (u8 *)dfu->bank->start;
		u8 *end_address    = (u8 *)dfu->bank->end;

		/* 
		   It is reasonable to assume that since the transfer
		   length is even and the size ARM code is always
		   divisible at least by two(each instruction is 16
		   bits in Thumb mode and 32 in non-Thumb) and DFU
		   suffix contains even number of bytes, in the even
		   of len parameter being odd, that something went
		   terribly wrong. 
		 */
		if (dfu->pending.block_len % 2) 
			return -1;

		if (dfu->pending.block_no == 0)
			dfu->block.writeptr = start_address;

		stfub_printf("[%d] dfu->block.writeptr = %x\n",
			     dfu->pending.block_no, dfu->block.writeptr);

		write_len = MIN(dfu->pending.block_len,
				end_address - dfu->block.writeptr);

		flash_unlock();
		flash_unlock_option_bytes();

		flash_erase_page((u32)dfu->block.writeptr);

		for (i = 0; i < write_len; i += 2)
			flash_program_half_word((u32)(dfu->block.writeptr + i),
						*(u16 *)(dfu->pending.block + i));
		
		flash_lock();

		dfu->block.writeptr += write_len;


		dfu->pending.block_len = -1;
		return 0;
	}
}

static bool stfub_dfu_attribute_is_set(struct stfub_dfu *dfu, u8 attribute)
{
	return dfu->descr->bmAttributes & attribute;
}

static enum dfu_state stfub_dfu_get_state(struct stfub_dfu *dfu)
{
	return dfu->state;
}

static void stfub_dfu_set_state(struct stfub_dfu *dfu,
				 enum dfu_state state)
{
	dfu->state = state;
}

static enum dfu_status stfub_dfu_get_status(struct stfub_dfu *dfu)
{
	return dfu->status;
}

static void stfub_dfu_set_status(struct stfub_dfu *dfu,
				  enum dfu_status status)
{
	dfu->status = status;
}

static u32 stfub_dfu_get_poll_timeout(struct stfub_dfu *dfu)
{
	return dfu->timeout;
}

static bool stfub_dfu_timeout_elapsed(struct stfub_dfu *dfu)
{
	/* FIXME: Implement proper timeout support */
	return true;
}

static int stfub_dfu_handle_get_status_request(struct stfub_dfu *dfu, u8 *buf,
						u16 *len)
{
	u32 timeout = stfub_dfu_get_poll_timeout(dfu);

	buf[0] = stfub_dfu_get_status(dfu);
	buf[1] = timeout & 0xFF;
	buf[2] = (timeout >> 8) & 0xFF;
	buf[3] = (timeout >> 16) & 0xFF;
	buf[4] = stfub_dfu_get_state(dfu);
	buf[5] = 0; /* iString not used here */
	*len   = 6;

	return USBD_REQ_HANDLED;
}

static int stfub_dfu_handle_get_state_request(struct stfub_dfu *dfu, u8 *buf,
					       u16 *len)
{
	buf[0] = stfub_dfu_get_state(dfu);
	*len   = 1;

	return USBD_REQ_HANDLED;
}

static void stfub_dfu_timestamp_poll_request(struct stfub_dfu *dfu)
{
}

static int stfub_dfu_queue_firmware_block(struct stfub_dfu *dfu,
					  u16 block_no, const u8 *buf,
					  int len)
{

	if ((unsigned int) len > sizeof(dfu->pending.block))
		return -1;

	dfu->pending.block_no = block_no;
	memcpy(dfu->pending.block, buf, len);
	
	dfu->pending.block_len = len;

	return 0;
}

static bool stfub_dfu_write_pending(struct stfub_dfu *dfu)
{
	return dfu->pending.block_len != -1;
}


static bool dfu_all_data_is_received(struct stfub_dfu *dfu)
{
	return true;
}

void stfub_dfu_tick(void)
{
	switch(stfub_dfu_get_state(&dfu)) {
	case STATE_DFU_DNBUSY:
		if (stfub_dfu_write_pending(&dfu)) 
			if (stfub_dfu_write_firmware_block(&dfu) < 0)  {
				stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
				break;
			}
			
		stfub_dfu_set_state(&dfu, STATE_DFU_DNLOAD_SYNC);
		break;
#if 0
	case STATE_DFU_MANIFEST:
		if (stfub_dfu_timeout_elapsed(&dfu)){ 
			if (stfub_dfu_attribute_is_set(&dfu, USB_DFU_MANIFEST_TOLERANT))
				stfub_dfu_set_state(&dfu, STATE_DFU_MANIFEST_SYNC);
			else
				stfub_dfu_set_state(&dfu, STATE_DFU_MANIFEST_WAIT_RESET);
		}
		break;
#endif
	default:
		break;

	}
}

int stfub_dfu_handle_control_request(usbd_device *udbddev, struct usb_setup_data *req, u8 **buf,
				     u16 *len, void (**complete)(usbd_device *udbddev, struct usb_setup_data *req))
{
	int read_size, requested_size;

	if ((req->bmRequestType & 0x7F) != 0x21)
		return USBD_REQ_NOTSUPP; /* Only accept class request. */

	stfub_dfu_timestamp_poll_request(&dfu);

	switch(stfub_dfu_get_state(&dfu)) {
	/* Table A.2.3 of the official DFU spec v 1.1 */
	case STATE_DFU_IDLE:
		switch (req->bRequest) {
		case DFU_DNLOAD:
			if ((len == NULL) || (*len == 0) ||
			    !stfub_dfu_attribute_is_set(&dfu, USB_DFU_CAN_DOWNLOAD)) {
				stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
				return USBD_REQ_NOTSUPP;
			}
			if (stfub_dfu_queue_firmware_block(&dfu, req->wValue,
							    *buf, *len) < 0) {
				stfub_dfu_set_status(&dfu, DFU_STATUS_ERR_UNKNOWN);
				stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
				return USBD_REQ_NOTSUPP;
			}
 			stfub_dfu_set_state(&dfu, STATE_DFU_DNLOAD_SYNC);
			return USBD_REQ_HANDLED;
		case DFU_UPLOAD:
			if (!stfub_dfu_attribute_is_set(&dfu, USB_DFU_CAN_UPLOAD)) {
				stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
				return USBD_REQ_NOTSUPP;
			}

			read_size = stfub_dfu_read_firmware_block(&dfu, req->wValue,
								  *buf, *len);
			if(read_size < 0) {
				stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
				*len = 0;
				return USBD_REQ_NOTSUPP;
			} else {
				stfub_dfu_set_state(&dfu, STATE_DFU_UPLOAD_IDLE);
				*len = read_size;
				return USBD_REQ_HANDLED;
			}
		case DFU_ABORT:
			return USBD_REQ_HANDLED;
		case DFU_GETSTATUS:
			return stfub_dfu_handle_get_status_request(&dfu, *buf, len);
		case DFU_GETSTATE:
			return stfub_dfu_handle_get_state_request(&dfu, *buf, len);
		default:
			break;
		}
		break;
	/* Table A.2.4 */
	case STATE_DFU_DNLOAD_SYNC:
		switch (req->bRequest) {
		case DFU_GETSTATUS:
			if (stfub_dfu_write_pending(&dfu))
				stfub_dfu_set_state(&dfu, STATE_DFU_DNBUSY);
			else
				stfub_dfu_set_state(&dfu, STATE_DFU_DNLOAD_IDLE);

			return stfub_dfu_handle_get_status_request(&dfu, *buf, len);
		case DFU_GETSTATE:
			return stfub_dfu_handle_get_state_request(&dfu, *buf, len);
		default:
			break;
		}
		break;
	/* Table A.2.5 */
	case STATE_DFU_DNBUSY:
		break;
	/* Table A.2.6 */
	case STATE_DFU_DNLOAD_IDLE:
		switch (req->bRequest) {
		case DFU_DNLOAD:
			if ((len == NULL) || (*len == 0)) {
				if (dfu_all_data_is_received(&dfu)) {
					stfub_dfu_set_state(&dfu, STATE_DFU_MANIFEST_SYNC);
					return USBD_REQ_HANDLED;
				} else {
					stfub_dfu_set_status(&dfu, DFU_STATUS_ERR_NOTDONE);
					stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
					return USBD_REQ_NOTSUPP;
				}
			}

			if (stfub_dfu_queue_firmware_block(&dfu, req->wValue,
							    *buf, *len) < 0) {
				stfub_dfu_set_status(&dfu, DFU_STATUS_ERR_UNKNOWN);
				stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
				return USBD_REQ_NOTSUPP;
			}
 			stfub_dfu_set_state(&dfu, STATE_DFU_DNLOAD_SYNC);
			return USBD_REQ_HANDLED;
		case DFU_ABORT:
			stfub_dfu_set_state(&dfu, STATE_DFU_IDLE);
			return USBD_REQ_HANDLED;
		case DFU_GETSTATUS:
			/* Since we are working in a polling mode the
			 * transfer will always be complete by the
			 * time this request is served */
			stfub_dfu_set_state(&dfu, STATE_DFU_DNLOAD_IDLE);
			return stfub_dfu_handle_get_status_request(&dfu, *buf, len);
		case DFU_GETSTATE:
			return stfub_dfu_handle_get_state_request(&dfu, *buf, len);
		default:
			break;
		}
		break;
	/* Table A.2.7 */
	case STATE_DFU_MANIFEST_SYNC:
		switch (req->bRequest) {
		case DFU_GETSTATE:
			return stfub_dfu_handle_get_state_request(&dfu, *buf, len);
		case DFU_GETSTATUS:
			if (stfub_dfu_attribute_is_set(&dfu, USB_DFU_MANIFEST_TOLERANT)) {
				/* Since we are working in a polling mode the
				 * manifestation will always be complete by the
				 * time this request is served */
				stfub_dfu_set_state(&dfu, STATE_DFU_IDLE);
			} else {
				stfub_dfu_set_state(&dfu, STATE_DFU_MANIFEST_WAIT_RESET);
			}
			return stfub_dfu_handle_get_status_request(&dfu, *buf, len);
		default:	/* FALLTHROUGH */
			break;
		}
		break;
	/* Table A.2.8 */
	case STATE_DFU_MANIFEST:
		/* Should never get here */
		break;
	/* Table A.2.9 */
	case STATE_DFU_MANIFEST_WAIT_RESET:
		return USBD_REQ_HANDLED;

	case STATE_DFU_UPLOAD_IDLE:
		switch (req->bRequest) {
		case DFU_UPLOAD:
			requested_size = *len;
			read_size = stfub_dfu_read_firmware_block(&dfu, req->wValue,
								  *buf, *len);
			*len = MIN(*len, read_size);

			if (read_size < 0) {
				stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
				*len = 0;
			}
			else if (read_size < requested_size) {
				stfub_dfu_set_state(&dfu, STATE_DFU_IDLE);
			}
			return USBD_REQ_HANDLED;
		case DFU_ABORT:
			stfub_dfu_set_state(&dfu, STATE_DFU_IDLE);
			return USBD_REQ_HANDLED;
		case DFU_GETSTATUS:
			return stfub_dfu_handle_get_status_request(&dfu, *buf, len);
		case DFU_GETSTATE:
			return stfub_dfu_handle_get_state_request(&dfu, *buf, len);
		default:
			break;
		}
		break;

	case STATE_DFU_ERROR:
		switch (req->bRequest) {
		case DFU_GETSTATUS:
			return stfub_dfu_handle_get_status_request(&dfu, *buf, len);
		case DFU_GETSTATE:
			return stfub_dfu_handle_get_state_request(&dfu, *buf, len);
		case DFU_CLRSTATUS:
			stfub_dfu_set_status(&dfu, DFU_STATUS_OK);
			stfub_dfu_set_state(&dfu, STATE_DFU_IDLE);
			return USBD_REQ_HANDLED;
		default:
			break;
		}
		break;
	default:
		break;
	}

	stfub_dfu_set_status(&dfu, DFU_STATUS_ERR_STALLEDPKT);
	stfub_dfu_set_state(&dfu, STATE_DFU_ERROR);
	return USBD_REQ_NOTSUPP;
}