net2280.c

ARM S3C2410 USB SLAVE LINUX驱动

/*
 * Driver for the PLX NET2280 USB device controller.
 * Specs and errata are available from <http://www.plxtech.com>.
 *
 * PLX Technology Inc. (formerly NetChip Technology) supported the 
 * development of this driver.
 *
 *
 * CODE STATUS HIGHLIGHTS
 *
 * This driver should work well with most "gadget" drivers, including
 * the File Storage, Serial, and Ethernet/RNDIS gadget drivers
 * as well as Gadget Zero and Gadgetfs.
 *
 * DMA is enabled by default.  Drivers using transfer queues might use
 * DMA chaining to remove IRQ latencies between transfers.  (Except when
 * short OUT transfers happen.)  Drivers can use the req->no_interrupt
 * hint to completely eliminate some IRQs, if a later IRQ is guaranteed
 * and DMA chaining is enabled.
 *
 * Note that almost all the errata workarounds here are only needed for
 * rev1 chips.  Rev1a silicon (0110) fixes almost all of them.
 */

/*
 * Copyright (C) 2003 David Brownell
 * Copyright (C) 2003-2005 PLX Technology, Inc.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#undef	DEBUG		/* messages on error and most fault paths */
#undef	VERBOSE		/* extra debug messages (success too) */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/usb_ch9.h>
#include <linux/usb_gadget.h>

#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/unaligned.h>


#define	DRIVER_DESC		"PLX NET2280 USB Peripheral Controller"
#define	DRIVER_VERSION		"2005 Feb 03"

#define	DMA_ADDR_INVALID	(~(dma_addr_t)0)
#define	EP_DONTUSE		13	/* nonzero */

#define USE_RDK_LEDS		/* GPIO pins control three LEDs */


static const char driver_name [] = "net2280";
static const char driver_desc [] = DRIVER_DESC;

static const char ep0name [] = "ep0";
static const char *ep_name [] = {
	ep0name,
	"ep-a", "ep-b", "ep-c", "ep-d",
	"ep-e", "ep-f",
};

/* use_dma -- general goodness, fewer interrupts, less cpu load (vs PIO)
 * use_dma_chaining -- dma descriptor queueing gives even more irq reduction
 *
 * The net2280 DMA engines are not tightly integrated with their FIFOs;
 * not all cases are (yet) handled well in this driver or the silicon.
 * Some gadget drivers work better with the dma support here than others.
 * These two parameters let you use PIO or more aggressive DMA.
 */
static int use_dma = 1;
static int use_dma_chaining = 0;

/* "modprobe net2280 use_dma=n" etc */
module_param (use_dma, bool, S_IRUGO);
module_param (use_dma_chaining, bool, S_IRUGO);


/* mode 0 == ep-{a,b,c,d} 1K fifo each
 * mode 1 == ep-{a,b} 2K fifo each, ep-{c,d} unavailable
 * mode 2 == ep-a 2K fifo, ep-{b,c} 1K each, ep-d unavailable
 */
static ushort fifo_mode = 0;

/* "modprobe net2280 fifo_mode=1" etc */
module_param (fifo_mode, ushort, 0644);

/* enable_suspend -- When enabled, the driver will respond to
 * USB suspend requests by powering down the NET2280.  Otherwise,
 * USB suspend requests will be ignored.  This is acceptible for
 * self-powered devices, and helps avoid some quirks.
 */
static int enable_suspend = 0;

/* "modprobe net2280 enable_suspend=1" etc */
module_param (enable_suspend, bool, S_IRUGO);


#define	DIR_STRING(bAddress) (((bAddress) & USB_DIR_IN) ? "in" : "out")

#if defined(CONFIG_USB_GADGET_DEBUG_FILES) || defined (DEBUG)
static char *type_string (u8 bmAttributes)
{
	switch ((bmAttributes) & USB_ENDPOINT_XFERTYPE_MASK) {
	case USB_ENDPOINT_XFER_BULK:	return "bulk";
	case USB_ENDPOINT_XFER_ISOC:	return "iso";
	case USB_ENDPOINT_XFER_INT:	return "intr";
	};
	return "control";
}
#endif

#include "net2280.h"

#define valid_bit	__constant_cpu_to_le32 (1 << VALID_BIT)
#define dma_done_ie	__constant_cpu_to_le32 (1 << DMA_DONE_INTERRUPT_ENABLE)

/*-------------------------------------------------------------------------*/

static int
net2280_enable (struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
	struct net2280		*dev;
	struct net2280_ep	*ep;
	u32			max, tmp;
	unsigned long		flags;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep || !desc || ep->desc || _ep->name == ep0name
			|| desc->bDescriptorType != USB_DT_ENDPOINT)
		return -EINVAL;
	dev = ep->dev;
	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;

	/* erratum 0119 workaround ties up an endpoint number */
	if ((desc->bEndpointAddress & 0x0f) == EP_DONTUSE)
		return -EDOM;

	/* sanity check ep-e/ep-f since their fifos are small */
	max = le16_to_cpu (desc->wMaxPacketSize) & 0x1fff;
	if (ep->num > 4 && max > 64)
		return -ERANGE;

	spin_lock_irqsave (&dev->lock, flags);
	_ep->maxpacket = max & 0x7ff;
	ep->desc = desc;

	/* ep_reset() has already been called */
	ep->stopped = 0;
	ep->out_overflow = 0;

	/* set speed-dependent max packet; may kick in high bandwidth */
	set_idx_reg (dev->regs, REG_EP_MAXPKT (dev, ep->num), max);

	/* FIFO lines can't go to different packets.  PIO is ok, so
	 * use it instead of troublesome (non-bulk) multi-packet DMA.
	 */
	if (ep->dma && (max % 4) != 0 && use_dma_chaining) {
		DEBUG (ep->dev, "%s, no dma for maxpacket %d\n",
			ep->ep.name, ep->ep.maxpacket);
		ep->dma = NULL;
	}

	/* set type, direction, address; reset fifo counters */
	writel ((1 << FIFO_FLUSH), &ep->regs->ep_stat);
	tmp = (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
	if (tmp == USB_ENDPOINT_XFER_INT) {
		/* erratum 0105 workaround prevents hs NYET */
		if (dev->chiprev == 0100
				&& dev->gadget.speed == USB_SPEED_HIGH
				&& !(desc->bEndpointAddress & USB_DIR_IN))
			writel ((1 << CLEAR_NAK_OUT_PACKETS_MODE),
				&ep->regs->ep_rsp);
	} else if (tmp == USB_ENDPOINT_XFER_BULK) {
		/* catch some particularly blatant driver bugs */
		if ((dev->gadget.speed == USB_SPEED_HIGH
					&& max != 512)
				|| (dev->gadget.speed == USB_SPEED_FULL
					&& max > 64)) {
			spin_unlock_irqrestore (&dev->lock, flags);
			return -ERANGE;
		}
	}
	ep->is_iso = (tmp == USB_ENDPOINT_XFER_ISOC) ? 1 : 0;
	tmp <<= ENDPOINT_TYPE;
	tmp |= desc->bEndpointAddress;
	tmp |= (4 << ENDPOINT_BYTE_COUNT);	/* default full fifo lines */
	tmp |= 1 << ENDPOINT_ENABLE;
	wmb ();

	/* for OUT transfers, block the rx fifo until a read is posted */
	ep->is_in = (tmp & USB_DIR_IN) != 0;
	if (!ep->is_in)
		writel ((1 << SET_NAK_OUT_PACKETS), &ep->regs->ep_rsp);

	writel (tmp, &ep->regs->ep_cfg);

	/* enable irqs */
	if (!ep->dma) {				/* pio, per-packet */
		tmp = (1 << ep->num) | readl (&dev->regs->pciirqenb0);
		writel (tmp, &dev->regs->pciirqenb0);

		tmp = (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
			| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE)
			| readl (&ep->regs->ep_irqenb);
		writel (tmp, &ep->regs->ep_irqenb);
	} else {				/* dma, per-request */
		tmp = (1 << (8 + ep->num));	/* completion */
		tmp |= readl (&dev->regs->pciirqenb1);
		writel (tmp, &dev->regs->pciirqenb1);

		/* for short OUT transfers, dma completions can't
		 * advance the queue; do it pio-style, by hand.
		 * NOTE erratum 0112 workaround #2
		 */
		if ((desc->bEndpointAddress & USB_DIR_IN) == 0) {
			tmp = (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT_ENABLE);
			writel (tmp, &ep->regs->ep_irqenb);

			tmp = (1 << ep->num) | readl (&dev->regs->pciirqenb0);
			writel (tmp, &dev->regs->pciirqenb0);
		}
	}

	tmp = desc->bEndpointAddress;
	DEBUG (dev, "enabled %s (ep%d%s-%s) %s max %04x\n",
		_ep->name, tmp & 0x0f, DIR_STRING (tmp),
		type_string (desc->bmAttributes),
		ep->dma ? "dma" : "pio", max);

	/* pci writes may still be posted */
	spin_unlock_irqrestore (&dev->lock, flags);
	return 0;
}

static int handshake (u32 __iomem *ptr, u32 mask, u32 done, int usec)
{
	u32	result;

	do {
		result = readl (ptr);
		if (result == ~(u32)0)		/* "device unplugged" */
			return -ENODEV;
		result &= mask;
		if (result == done)
			return 0;
		udelay (1);
		usec--;
	} while (usec > 0);
	return -ETIMEDOUT;
}

static struct usb_ep_ops net2280_ep_ops;

static void ep_reset (struct net2280_regs __iomem *regs, struct net2280_ep *ep)
{
	u32		tmp;

	ep->desc = NULL;
	INIT_LIST_HEAD (&ep->queue);

	ep->ep.maxpacket = ~0;
	ep->ep.ops = &net2280_ep_ops;

	/* disable the dma, irqs, endpoint... */
	if (ep->dma) {
		writel (0, &ep->dma->dmactl);
		writel (  (1 << DMA_SCATTER_GATHER_DONE_INTERRUPT)
			| (1 << DMA_TRANSACTION_DONE_INTERRUPT)
			| (1 << DMA_ABORT)
			, &ep->dma->dmastat);

		tmp = readl (&regs->pciirqenb0);
		tmp &= ~(1 << ep->num);
		writel (tmp, &regs->pciirqenb0);
	} else {
		tmp = readl (&regs->pciirqenb1);
		tmp &= ~(1 << (8 + ep->num));	/* completion */
		writel (tmp, &regs->pciirqenb1);
	}
	writel (0, &ep->regs->ep_irqenb);

	/* init to our chosen defaults, notably so that we NAK OUT
	 * packets until the driver queues a read (+note erratum 0112)
	 */
	tmp = (1 << SET_NAK_OUT_PACKETS_MODE)
		| (1 << SET_NAK_OUT_PACKETS)
		| (1 << CLEAR_EP_HIDE_STATUS_PHASE)
		| (1 << CLEAR_INTERRUPT_MODE);

	if (ep->num != 0) {
		tmp |= (1 << CLEAR_ENDPOINT_TOGGLE)
			| (1 << CLEAR_ENDPOINT_HALT);
	}
	writel (tmp, &ep->regs->ep_rsp);

	/* scrub most status bits, and flush any fifo state */
	writel (  (1 << TIMEOUT)
		| (1 << USB_STALL_SENT)
		| (1 << USB_IN_NAK_SENT)
		| (1 << USB_IN_ACK_RCVD)
		| (1 << USB_OUT_PING_NAK_SENT)
		| (1 << USB_OUT_ACK_SENT)
		| (1 << FIFO_OVERFLOW)
		| (1 << FIFO_UNDERFLOW)
		| (1 << FIFO_FLUSH)
		| (1 << SHORT_PACKET_OUT_DONE_INTERRUPT)
		| (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)
		| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
		| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
		| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
		| (1 << DATA_IN_TOKEN_INTERRUPT)
		, &ep->regs->ep_stat);

	/* fifo size is handled separately */
}

static void nuke (struct net2280_ep *);

static int net2280_disable (struct usb_ep *_ep)
{
	struct net2280_ep	*ep;
	unsigned long		flags;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep || !ep->desc || _ep->name == ep0name)
		return -EINVAL;

	spin_lock_irqsave (&ep->dev->lock, flags);
	nuke (ep);
	ep_reset (ep->dev->regs, ep);

	VDEBUG (ep->dev, "disabled %s %s\n",
			ep->dma ? "dma" : "pio", _ep->name);

	/* synch memory views with the device */
	(void) readl (&ep->regs->ep_cfg);

	if (use_dma && !ep->dma && ep->num >= 1 && ep->num <= 4)
		ep->dma = &ep->dev->dma [ep->num - 1];

	spin_unlock_irqrestore (&ep->dev->lock, flags);
	return 0;
}

/*-------------------------------------------------------------------------*/

static struct usb_request *
net2280_alloc_request (struct usb_ep *_ep, unsigned gfp_flags)
{
	struct net2280_ep	*ep;
	struct net2280_request	*req;

	if (!_ep)
		return NULL;
	ep = container_of (_ep, struct net2280_ep, ep);

	req = kmalloc (sizeof *req, gfp_flags);
	if (!req)
		return NULL;

	memset (req, 0, sizeof *req);
	req->req.dma = DMA_ADDR_INVALID;
	INIT_LIST_HEAD (&req->queue);

	/* this dma descriptor may be swapped with the previous dummy */
	if (ep->dma) {
		struct net2280_dma	*td;

		td = pci_pool_alloc (ep->dev->requests, gfp_flags,
				&req->td_dma);
		if (!td) {
			kfree (req);
			return NULL;
		}
		td->dmacount = 0;	/* not VALID */
		td->dmaaddr = __constant_cpu_to_le32 (DMA_ADDR_INVALID);
		td->dmadesc = td->dmaaddr;
		req->td = td;
	}
	return &req->req;
}

static void
net2280_free_request (struct usb_ep *_ep, struct usb_request *_req)
{
	struct net2280_ep	*ep;
	struct net2280_request	*req;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep || !_req)
		return;

	req = container_of (_req, struct net2280_request, req);
	WARN_ON (!list_empty (&req->queue));
	if (req->td)
		pci_pool_free (ep->dev->requests, req->td, req->td_dma);
	kfree (req);
}

/*-------------------------------------------------------------------------*/

#undef USE_KMALLOC

/* many common platforms have dma-coherent caches, which means that it's
 * safe to use kmalloc() memory for all i/o buffers without using any
 * cache flushing calls.  (unless you're trying to share cache lines
 * between dma and non-dma activities, which is a slow idea in any case.)
 *
 * other platforms need more care, with 2.5 having a moderately general
 * solution (which falls down for allocations smaller than one page)
 * that improves significantly on the 2.4 PCI allocators by removing
 * the restriction that memory never be freed in_interrupt().
 */
#if	defined(CONFIG_X86)
#define USE_KMALLOC

#elif	defined(CONFIG_PPC) && !defined(CONFIG_NOT_COHERENT_CACHE)
#define USE_KMALLOC

#elif	defined(CONFIG_MIPS) && !defined(CONFIG_DMA_NONCOHERENT)
#define USE_KMALLOC

/* FIXME there are other cases, including an x86-64 one ...  */
#endif

/* allocating buffers this way eliminates dma mapping overhead, which
 * on some platforms will mean eliminating a per-io buffer copy.  with
 * some kinds of system caches, further tweaks may still be needed.
 */
static void *
net2280_alloc_buffer (
	struct usb_ep		*_ep,
	unsigned		bytes,
	dma_addr_t		*dma,
	unsigned		gfp_flags
)
{
	void			*retval;
	struct net2280_ep	*ep;

	ep = container_of (_ep, struct net2280_ep, ep);
	if (!_ep)