barebox/drivers/usb/storage/transport.c

/*
 * Most of this source has been derived from the Linux and
 * U-Boot USB Mass Storage driver implementations.
 *
 * Adapted for barebox:
 * Copyright (c) 2011, AMK Drives & Controls Ltd.
 *
 * 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 2 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.
 *
 *
 */

#include <common.h>
#include <clock.h>
#include <scsi.h>
#include <errno.h>
#include <dma.h>

#undef USB_STOR_DEBUG

#include "usb.h"
#include "transport.h"


/* The timeout argument of usb_bulk_msg() is actually ignored
   and the timeout is hardcoded in the host driver */
#define USB_BULK_TO		5000

static __u32 cbw_tag = 0;

/* direction table -- this indicates the direction of the data
 * transfer for each command code (bit-encoded) -- 1 indicates input
 * note that this doesn't work for shared command codes
 */
static const unsigned char us_direction[256/8] = {
	0x28, 0x81, 0x14, 0x14, 0x20, 0x01, 0x90, 0x77,
	0x0C, 0x20, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00,
	0x00, 0x01, 0x00, 0x40, 0x09, 0x01, 0x80, 0x01,
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
#define US_DIRECTION(x) ((us_direction[x>>3] >> (x & 7)) & 1)


/*
 * Bulk only transport
 */

/* Clear a stall on an endpoint - special for bulk-only devices */
int usb_stor_Bulk_clear_endpt_stall(struct us_data *us, unsigned int pipe)
{
	return usb_clear_halt(us->pusb_dev, pipe);
}

/* Determine what the maximum LUN supported is */
int usb_stor_Bulk_max_lun(struct us_data *us)
{
	int len, ret = 0;
	unsigned char *iobuf = dma_alloc(1);

	/* issue the command */
	iobuf[0] = 0;
	len = usb_control_msg(us->pusb_dev,
	                      usb_rcvctrlpipe(us->pusb_dev, 0),
	                      US_BULK_GET_MAX_LUN,
	                      USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
	                      0, us->ifnum, iobuf, 1, USB_CNTL_TIMEOUT);

	US_DEBUGP("GetMaxLUN command result is %d, data is %d\n",
	          len, (int)iobuf[0]);

	/* if we have a successful request, return the result */
	if (len > 0)
		ret = iobuf[0];

	dma_free(iobuf);

	/*
	 * Some devices don't like GetMaxLUN.  They may STALL the control
	 * pipe, they may return a zero-length result, they may do nothing at
	 * all and timeout, or they may fail in even more bizarrely creative
	 * ways.  In these cases the best approach is to use the default
	 * value: only one LUN.
	 */
	return ret;
}

int usb_stor_Bulk_transport(ccb *srb, struct us_data *us)
{
	struct bulk_cb_wrap cbw;
	struct bulk_cs_wrap csw;
	int actlen, data_actlen;
	int result;
	unsigned int residue;
	unsigned int pipein = usb_rcvbulkpipe(us->pusb_dev, us->recv_bulk_ep);
	unsigned int pipeout = usb_sndbulkpipe(us->pusb_dev, us->send_bulk_ep);
	int dir_in = US_DIRECTION(srb->cmd[0]);

	srb->trans_bytes = 0;

	/* set up the command wrapper */
	cbw.Signature = cpu_to_le32(US_BULK_CB_SIGN);
	cbw.DataTransferLength = cpu_to_le32(srb->datalen);
	cbw.Flags = (dir_in ? US_BULK_FLAG_IN : US_BULK_FLAG_OUT);
	cbw.Tag = ++cbw_tag;
	cbw.Lun = srb->lun;
	cbw.Length = srb->cmdlen;

	/* copy the command payload */
	memcpy(cbw.CDB, srb->cmd, cbw.Length);

	/* send it to out endpoint */
	US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
	                le32_to_cpu(cbw.Signature), cbw.Tag,
	                le32_to_cpu(cbw.DataTransferLength), cbw.Flags,
	                (cbw.Lun >> 4), (cbw.Lun & 0x0F),
	                cbw.Length);
	result = usb_bulk_msg(us->pusb_dev, pipeout, &cbw, US_BULK_CB_WRAP_LEN,
			      &actlen, USB_BULK_TO);
	US_DEBUGP("Bulk command transfer result=%d\n", result);
	if (result < 0) {
		usb_stor_Bulk_reset(us);
		return USB_STOR_TRANSPORT_FAILED;
	}

	/* DATA STAGE */
	/* send/receive data payload, if there is any */

	mdelay(1);

	data_actlen = 0;
	if (srb->datalen) {
		unsigned int pipe = dir_in ? pipein : pipeout;
		result = usb_bulk_msg(us->pusb_dev, pipe, srb->pdata,
		                      srb->datalen, &data_actlen, USB_BULK_TO);
		US_DEBUGP("Bulk data transfer result 0x%x\n", result);
		/* special handling of STALL in DATA phase */
		if ((result < 0) && (us->pusb_dev->status & USB_ST_STALLED)) {
			US_DEBUGP("DATA: stall\n");
			/* clear the STALL on the endpoint */
			result = usb_stor_Bulk_clear_endpt_stall(us, pipe);
		}
		if (result < 0) {
			US_DEBUGP("Device status: %lx\n", us->pusb_dev->status);
			usb_stor_Bulk_reset(us);
			return USB_STOR_TRANSPORT_FAILED;
		}
	}

	/* STATUS phase + error handling */
	US_DEBUGP("Attempting to get CSW...\n");
	result = usb_bulk_msg(us->pusb_dev, pipein, &csw, US_BULK_CS_WRAP_LEN,
	                      &actlen, USB_BULK_TO);

	/* did the endpoint stall? */
	if ((result < 0) && (us->pusb_dev->status & USB_ST_STALLED)) {
		US_DEBUGP("STATUS: stall\n");
		/* clear the STALL on the endpoint */
		result = usb_stor_Bulk_clear_endpt_stall(us, pipein);
		if (result >= 0) {
			US_DEBUGP("Attempting to get CSW...\n");
			result = usb_bulk_msg(us->pusb_dev, pipein,
			                      &csw, US_BULK_CS_WRAP_LEN,
			                      &actlen, USB_BULK_TO);
		}
	}

	if (result < 0) {
		US_DEBUGP("Device status: %lx\n", us->pusb_dev->status);
		usb_stor_Bulk_reset(us);
		return USB_STOR_TRANSPORT_FAILED;
	}

	/* check bulk status */
	residue = le32_to_cpu(csw.Residue);
	US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
	          le32_to_cpu(csw.Signature), csw.Tag, residue, csw.Status);
	if (csw.Signature != cpu_to_le32(US_BULK_CS_SIGN)) {
		US_DEBUGP("Bad CSW signature\n");
		usb_stor_Bulk_reset(us);
		return USB_STOR_TRANSPORT_FAILED;
	} else if (csw.Tag != cbw_tag) {
		US_DEBUGP("Mismatching tag\n");
		usb_stor_Bulk_reset(us);
		return USB_STOR_TRANSPORT_FAILED;
	} else if (csw.Status >= US_BULK_STAT_PHASE) {
		US_DEBUGP("Status >= phase\n");
		usb_stor_Bulk_reset(us);
		return USB_STOR_TRANSPORT_ERROR;
	} else if (residue > srb->datalen) {
		US_DEBUGP("residue (%uB) > req data (%luB)\n",
		          residue, srb->datalen);
		return USB_STOR_TRANSPORT_FAILED;
	} else if (csw.Status == US_BULK_STAT_FAIL) {
		US_DEBUGP("FAILED\n");
		return USB_STOR_TRANSPORT_FAILED;
	}
	srb->trans_bytes = min(srb->datalen - residue, (ulong)data_actlen);

	return 0;
}


/* This issues a Bulk-only Reset to the device in question, including
 * clearing the subsequent endpoint halts that may occur.
 */
int usb_stor_Bulk_reset(struct us_data *us)
{
	int result;
	int result2;
	unsigned int pipe;

	US_DEBUGP("%s called\n", __func__);

	/* issue the command */
	result = usb_control_msg(us->pusb_dev,
	                         usb_sndctrlpipe(us->pusb_dev, 0),
	                         US_BULK_RESET_REQUEST,
	                         USB_TYPE_CLASS | USB_RECIP_INTERFACE,
	                         0, us->ifnum, 0, 0, USB_CNTL_TIMEOUT);
	if ((result < 0) && (us->pusb_dev->status & USB_ST_STALLED)) {
		US_DEBUGP("Soft reset stalled: %d\n", result);
		return result;
	}
	mdelay(150);

	/* clear the bulk endpoints halt */
	US_DEBUGP("Soft reset: clearing %s endpoint halt\n", "bulk-in");
	pipe = usb_rcvbulkpipe(us->pusb_dev, us->recv_bulk_ep);
	result = usb_clear_halt(us->pusb_dev, pipe);
	mdelay(150);
	US_DEBUGP("Soft reset: clearing %s endpoint halt\n", "bulk-out");
	pipe = usb_sndbulkpipe(us->pusb_dev, us->send_bulk_ep);
	result2 = usb_clear_halt(us->pusb_dev, pipe);
	mdelay(150);

	if (result >= 0)
		result = result2;
	US_DEBUGP("Soft reset %s\n", ((result < 0) ? "failed" : "done"));

	return result;
}