goku_udc.c

LINUX2.4.18内核下的usb GADGET驱动程序

/*
 * Toshiba TC86C001 ("Goku-S") USB Device Controller driver
 *
 * Copyright (C) 2000-2002 Lineo
 *      by Stuart Lynne, Tom Rushworth, and Bruce Balden
 * Copyright (C) 2002 Toshiba Corporation
 * Copyright (C) 2003 MontaVista Software ([e-mail])
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

/*
 * This device has ep0 and three semi-configurable bulk/interrupt endpoints.
 *
 *  - Endpoint numbering is fixed: ep{1,2,3}-bulk
 *  - Gadget drivers can choose ep maxpacket (8/16/32/64)
 *  - Gadget drivers can choose direction (IN, OUT)
 *  - DMA works with ep1 (OUT transfers) and ep2 (IN transfers).
 */

#undef DEBUG
// #define	VERBOSE		/* extra debug messages (success too) */
// #define	USB_TRACE	/* packet-level success messages */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.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/proc_fs.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>


#include "goku_udc.h"

#define	DRIVER_DESC		"TC86C001 USB Device Controller"
#define	DRIVER_VERSION		"30-Oct 2003"

#define	DMA_ADDR_INVALID	(~(dma_addr_t)0)

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

MODULE_AUTHOR("[e-mail]");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");


/*
 * IN dma behaves ok under testing, though the IN-dma abort paths don't
 * seem to behave quite as expected.  Used by default.
 *
 * OUT dma documents design problems handling the common "short packet"
 * transfer termination policy; it couldn't enabled by default, even
 * if the OUT-dma abort problems had a resolution.
 */
static unsigned use_dma = 1;

#if 0
//#include <linux/moduleparam.h>
/* "modprobe goku_udc use_dma=1" etc
 *	0 to disable dma
 *	1 to use IN dma only (normal operation)
 *	2 to use IN and OUT dma
 */
module_param(use_dma, uint, S_IRUGO);
#endif

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

static void nuke(struct goku_ep *, int status);

static inline void
command(struct goku_udc_regs *regs, int command, unsigned epnum)
{
	writel(COMMAND_EP(epnum) | command, &regs->Command);
	udelay(300);
}

static int
goku_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
	struct goku_udc	*dev;
	struct goku_ep	*ep;
	u32		mode;
	u16		max;
	unsigned long	flags;

	ep = container_of(_ep, struct goku_ep, ep);
	if (!_ep || !desc || ep->desc
			|| desc->bDescriptorType != USB_DT_ENDPOINT)
		return -EINVAL;
	dev = ep->dev;
	if (ep == &dev->ep[0])
		return -EINVAL;
	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;
	if (ep->num != (desc->bEndpointAddress & 0x0f))
		return -EINVAL;

	switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
	case USB_ENDPOINT_XFER_BULK:
	case USB_ENDPOINT_XFER_INT:
		break;
	default:
		return -EINVAL;
	}

	if ((readl(ep->reg_status) & EPxSTATUS_EP_MASK)
			!= EPxSTATUS_EP_INVALID)
		return -EBUSY;

	/* enabling the no-toggle interrupt mode would need an api hook */
	mode = 0;
	max = le16_to_cpu(get_unaligned(&desc->wMaxPacketSize));
	switch (max) {
	case 64:	mode++;
	case 32:	mode++;
	case 16:	mode++;
	case 8:		mode <<= 3;
			break;
	default:
		return -EINVAL;
	}
	mode |= 2 << 1;		/* bulk, or intr-with-toggle */

	/* ep1/ep2 dma direction is chosen early; it works in the other
	 * direction, with pio.  be cautious with out-dma.
	 */
	ep->is_in = (USB_DIR_IN & desc->bEndpointAddress) != 0;
	if (ep->is_in) {
		mode |= 1;
		ep->dma = (use_dma != 0) && (ep->num == UDC_MSTRD_ENDPOINT);
	} else {
		ep->dma = (use_dma == 2) && (ep->num == UDC_MSTWR_ENDPOINT);
		if (ep->dma)
			DBG(dev, "%s out-dma hides short packets\n",
				ep->ep.name);
	}

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

	/* ep1 and ep2 can do double buffering and/or dma */
	if (ep->num < 3) {
		struct goku_udc_regs	*regs = ep->dev->regs;
		u32			tmp;

		/* double buffer except (for now) with pio in */
		tmp = ((ep->dma || !ep->is_in)
				? 0x10	/* double buffered */
				: 0x11	/* single buffer */
			) << ep->num;
		tmp |= readl(&regs->EPxSingle);
		writel(tmp, &regs->EPxSingle);

		tmp = (ep->dma ? 0x10/*dma*/ : 0x11/*pio*/) << ep->num;
		tmp |= readl(&regs->EPxBCS);
		writel(tmp, &regs->EPxBCS);
	}
	writel(mode, ep->reg_mode);
	command(ep->dev->regs, COMMAND_RESET, ep->num);
	ep->ep.maxpacket = max;
	ep->stopped = 0;
	ep->desc = desc;
	spin_unlock_irqrestore(&ep->dev->lock, flags);

	DBG(dev, "enable %s %s %s maxpacket %u\n", ep->ep.name,
		ep->is_in ? "IN" : "OUT",
		ep->dma ? "dma" : "pio",
		max);

	return 0;
}

static void ep_reset(struct goku_udc_regs *regs, struct goku_ep *ep)
{
	struct goku_udc		*dev = ep->dev;

	if (regs) {
		command(regs, COMMAND_INVALID, ep->num);
		if (ep->num) {
			if (ep->num == UDC_MSTWR_ENDPOINT)
				dev->int_enable &= ~(INT_MSTWREND
							|INT_MSTWRTMOUT);
			else if (ep->num == UDC_MSTRD_ENDPOINT)
				dev->int_enable &= ~INT_MSTRDEND;
			dev->int_enable &= ~INT_EPxDATASET (ep->num);
		} else
			dev->int_enable &= ~INT_EP0;
		writel(dev->int_enable, &regs->int_enable);
		readl(&regs->int_enable);
		if (ep->num < 3) {
			struct goku_udc_regs	*regs = ep->dev->regs;
			u32			tmp;

			tmp = readl(&regs->EPxSingle);
			tmp &= ~(0x11 << ep->num);
			writel(tmp, &regs->EPxSingle);

			tmp = readl(&regs->EPxBCS);
			tmp &= ~(0x11 << ep->num);
			writel(tmp, &regs->EPxBCS);
		}
		/* reset dma in case we're still using it */
		if (ep->dma) {
			u32	master;

			master = readl(&regs->dma_master) & MST_RW_BITS;
			if (ep->num == UDC_MSTWR_ENDPOINT) {
				master &= ~MST_W_BITS;
				master |= MST_WR_RESET;
			} else {
				master &= ~MST_R_BITS;
				master |= MST_RD_RESET;
			}
			writel(master, &regs->dma_master);
		}
	}

	ep->ep.maxpacket = MAX_FIFO_SIZE;
	ep->desc = 0;
	ep->stopped = 1;
	ep->irqs = 0;
	ep->dma = 0;
}

static int goku_ep_disable(struct usb_ep *_ep)
{
	struct goku_ep	*ep;
	struct goku_udc	*dev;
	unsigned long	flags;

	ep = container_of(_ep, struct goku_ep, ep);
	if (!_ep || !ep->desc)
		return -ENODEV;
	dev = ep->dev;
	if (dev->ep0state == EP0_SUSPEND)
		return -EBUSY;

	VDBG(dev, "disable %s\n", _ep->name);

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

	return 0;
}

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

static struct usb_request *
goku_alloc_request(struct usb_ep *_ep, int gfp_flags)
{
	struct goku_request	*req;

	if (!_ep)
		return 0;
	req = kmalloc(sizeof *req, gfp_flags);
	if (!req)
		return 0;

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

static void
goku_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
	struct goku_request	*req;

	if (!_ep || !_req)
		return;

	req = container_of(_req, struct goku_request, req);
	WARN_ON(!list_empty(&req->queue));
	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 2.6 having a moderately general
 * solution except for the common "buffer is smaller than a page" case.
 */
#if	defined(CONFIG_X86)
#define USE_KMALLOC

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

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

#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 *
goku_alloc_buffer(struct usb_ep *_ep, unsigned bytes,
			dma_addr_t *dma, int  gfp_flags)
{
	void		*retval;
	struct goku_ep	*ep;

	ep = container_of(_ep, struct goku_ep, ep);
	if (!_ep)
		return 0;
	*dma = DMA_ADDR_INVALID;

#if	defined(USE_KMALLOC)
	retval = kmalloc(bytes, gfp_flags);
	if (retval)
		*dma = virt_to_phys(retval);
#else
	if (ep->dma) {
		/* one problem with this call is that it wastes memory on
		 * typical 1/N page allocations: it allocates 1-N pages.
		 * another is that it always uses GFP_ATOMIC.
		 */
#warning Using pci_alloc_consistent even with buffers smaller than a page.
		retval = pci_alloc_consistent(ep->dev->pdev, bytes, dma);
	} else
		retval = kmalloc(bytes, gfp_flags);
#endif
	return retval;
}

static void
goku_free_buffer(struct usb_ep *_ep, void *buf, dma_addr_t dma, unsigned bytes)
{
	/* free memory into the right allocator */
#ifndef	USE_KMALLOC
	if (dma != DMA_ADDR_INVALID) {
		struct goku_ep	*ep;

		ep = container_of(_ep, struct goku_ep, ep);
		if (!_ep)
			return;
		/* one problem with this call is that some platforms
		 * don't allow it to be used in_irq().
		 */
		pci_free_consistent(ep->dev->pdev, bytes, buf, dma);
	} else
#endif
		kfree (buf);
}

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

static void
done(struct goku_ep *ep, struct goku_request *req, int status)
{
	struct goku_udc		*dev;
	unsigned		stopped = ep->stopped;

	list_del_init(&req->queue);

	if (likely(req->req.status == -EINPROGRESS))
		req->req.status = status;
	else
		status = req->req.status;

	dev = ep->dev;
	if (req->mapped) {
		pci_unmap_single(dev->pdev, req->req.dma, req->req.length,
			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
		req->req.dma = DMA_ADDR_INVALID;
		req->mapped = 0;
	}

#ifndef USB_TRACE
	if (status && status != -ESHUTDOWN)
#endif
		VDBG(dev, "complete %s req %p stat %d len %u/%u\n",
			ep->ep.name, &req->req, status,
			req->req.actual, req->req.length);

	/* don't modify queue heads during completion callback */
	ep->stopped = 1;
	spin_unlock(&dev->lock);
	req->req.complete(&ep->ep, &req->req);
	spin_lock(&dev->lock);
	ep->stopped = stopped;
}

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

static inline int
write_packet(u32 *fifo, u8 *buf, struct goku_request *req, unsigned max)
{
	unsigned	length, count;

	length = min(req->req.length - req->req.actual, max);
	req->req.actual += length;

	count = length;
	while (likely(count--))
		writel(*buf++, fifo);
	return length;
}

// return:  0 = still running, 1 = completed, negative = errno
static int write_fifo(struct goku_ep *ep, struct goku_request *req)
{
	struct goku_udc	*dev = ep->dev;
	u32		tmp;
	u8		*buf;
	unsigned	count;
	int		is_last;

	tmp = readl(&dev->regs->DataSet);
	buf = req->req.buf + req->req.actual;
	prefetch(buf);

	dev = ep->dev;
	if (unlikely(ep->num == 0 && dev->ep0state != EP0_IN))
		return -EL2HLT;

	/* NOTE:  just single-buffered PIO-IN for now.  */
	if (unlikely((tmp & DATASET_A(ep->num)) != 0))
		return 0;

	/* clear our "packet available" irq */
	if (ep->num != 0)
		writel(~INT_EPxDATASET(ep->num), &dev->regs->int_status);

	count = write_packet(ep->reg_fifo, buf, req, ep->ep.maxpacket);

	/* last packet often short (sometimes a zlp, especially on ep0) */
	if (unlikely(count != ep->ep.maxpacket)) {
		writel(~(1<<ep->num), &dev->regs->EOP);
		if (ep->num == 0) {
			dev->ep[0].stopped = 1;
			dev->ep0state = EP0_STATUS;
		}
		is_last = 1;
	} else {
		if (likely(req->req.length != req->req.actual)
				|| req->req.zero)
			is_last = 0;
		else
			is_last = 1;
	}
#if 0		/* printk seemed to trash is_last...*/
//#ifdef USB_TRACE
	VDBG(dev, "wrote %s %u bytes%s IN %u left %p\n",
		ep->ep.name, count, is_last ? "/last" : "",
		req->req.length - req->req.actual, req);
#endif

	/* requests complete when all IN data is in the FIFO,
	 * or sometimes later, if a zlp was needed.
	 */
	if (is_last) {
		done(ep, req, 0);
		return 1;
	}

	return 0;
}

static int read_fifo(struct goku_ep *ep, struct goku_request *req)
{
	struct goku_udc_regs	*regs;
	u32			size, set;