at91_udc.c

linux下面gadget设备驱动

/*
 * at91_udc -- driver for at91-series USB peripheral controller
 *
 * Copyright (C) 2004 by Thomas Rathbone
 * Copyright (C) 2005 by HP Labs
 * Copyright (C) 2005 by David Brownell
 *
 * 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
#undef	VERBOSE
#undef	PACKET_TRACE

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/clk.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include <asm/byteorder.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/mach-types.h>

#include <asm/arch/gpio.h>
#include <asm/arch/board.h>
#include <asm/arch/cpu.h>
#include <asm/arch/at91sam9261_matrix.h>

#include "at91_udc.h"


/*
 * This controller is simple and PIO-only.  It's used in many AT91-series
 * full speed USB controllers, including the at91rm9200 (arm920T, with MMU),
 * at91sam926x (arm926ejs, with MMU), and several no-mmu versions.
 *
 * This driver expects the board has been wired with two GPIOs suppporting
 * a VBUS sensing IRQ, and a D+ pullup.  (They may be omitted, but the
 * testing hasn't covered such cases.)
 *
 * The pullup is most important (so it's integrated on sam926x parts).  It
 * provides software control over whether the host enumerates the device.
 *
 * The VBUS sensing helps during enumeration, and allows both USB clocks
 * (and the transceiver) to stay gated off until they're necessary, saving
 * power.  During USB suspend, the 48 MHz clock is gated off in hardware;
 * it may also be gated off by software during some Linux sleep states.
 */

#define	DRIVER_VERSION	"3 May 2006"

static const char driver_name [] = "at91_udc";
static const char ep0name[] = "ep0";


#define at91_udp_read(dev, reg) \
	__raw_readl((dev)->udp_baseaddr + (reg))
#define at91_udp_write(dev, reg, val) \
	__raw_writel((val), (dev)->udp_baseaddr + (reg))

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

#ifdef CONFIG_USB_GADGET_DEBUG_FILES

#include <linux/seq_file.h>

static const char debug_filename[] = "driver/udc";

#define FOURBITS "%s%s%s%s"
#define EIGHTBITS FOURBITS FOURBITS

static void proc_ep_show(struct seq_file *s, struct at91_ep *ep)
{
	static char		*types[] = {
		"control", "out-iso", "out-bulk", "out-int",
		"BOGUS",   "in-iso",  "in-bulk",  "in-int"};

	u32			csr;
	struct at91_request	*req;
	unsigned long	flags;

	local_irq_save(flags);

	csr = __raw_readl(ep->creg);

	/* NOTE:  not collecting per-endpoint irq statistics... */

	seq_printf(s, "\n");
	seq_printf(s, "%s, maxpacket %d %s%s %s%s\n",
			ep->ep.name, ep->ep.maxpacket,
			ep->is_in ? "in" : "out",
			ep->is_iso ? " iso" : "",
			ep->is_pingpong
				? (ep->fifo_bank ? "pong" : "ping")
				: "",
			ep->stopped ? " stopped" : "");
	seq_printf(s, "csr %08x rxbytes=%d %s %s %s" EIGHTBITS "\n",
		csr,
		(csr & 0x07ff0000) >> 16,
		(csr & (1 << 15)) ? "enabled" : "disabled",
		(csr & (1 << 11)) ? "DATA1" : "DATA0",
		types[(csr & 0x700) >> 8],

		/* iff type is control then print current direction */
		(!(csr & 0x700))
			? ((csr & (1 << 7)) ? " IN" : " OUT")
			: "",
		(csr & (1 << 6)) ? " rxdatabk1" : "",
		(csr & (1 << 5)) ? " forcestall" : "",
		(csr & (1 << 4)) ? " txpktrdy" : "",

		(csr & (1 << 3)) ? " stallsent" : "",
		(csr & (1 << 2)) ? " rxsetup" : "",
		(csr & (1 << 1)) ? " rxdatabk0" : "",
		(csr & (1 << 0)) ? " txcomp" : "");
	if (list_empty (&ep->queue))
		seq_printf(s, "\t(queue empty)\n");

	else list_for_each_entry (req, &ep->queue, queue) {
		unsigned	length = req->req.actual;

		seq_printf(s, "\treq %p len %d/%d buf %p\n",
				&req->req, length,
				req->req.length, req->req.buf);
	}
	local_irq_restore(flags);
}

static void proc_irq_show(struct seq_file *s, const char *label, u32 mask)
{
	int i;

	seq_printf(s, "%s %04x:%s%s" FOURBITS, label, mask,
		(mask & (1 << 13)) ? " wakeup" : "",
		(mask & (1 << 12)) ? " endbusres" : "",

		(mask & (1 << 11)) ? " sofint" : "",
		(mask & (1 << 10)) ? " extrsm" : "",
		(mask & (1 << 9)) ? " rxrsm" : "",
		(mask & (1 << 8)) ? " rxsusp" : "");
	for (i = 0; i < 8; i++) {
		if (mask & (1 << i))
			seq_printf(s, " ep%d", i);
	}
	seq_printf(s, "\n");
}

static int proc_udc_show(struct seq_file *s, void *unused)
{
	struct at91_udc	*udc = s->private;
	struct at91_ep	*ep;
	u32		tmp;

	seq_printf(s, "%s: version %s\n", driver_name, DRIVER_VERSION);

	seq_printf(s, "vbus %s, pullup %s, %s powered%s, gadget %s\n\n",
		udc->vbus ? "present" : "off",
		udc->enabled
			? (udc->vbus ? "active" : "enabled")
			: "disabled",
		udc->selfpowered ? "self" : "VBUS",
		udc->suspended ? ", suspended" : "",
		udc->driver ? udc->driver->driver.name : "(none)");

	/* don't access registers when interface isn't clocked */
	if (!udc->clocked) {
		seq_printf(s, "(not clocked)\n");
		return 0;
	}

	tmp = at91_udp_read(udc, AT91_UDP_FRM_NUM);
	seq_printf(s, "frame %05x:%s%s frame=%d\n", tmp,
		(tmp & AT91_UDP_FRM_OK) ? " ok" : "",
		(tmp & AT91_UDP_FRM_ERR) ? " err" : "",
		(tmp & AT91_UDP_NUM));

	tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
	seq_printf(s, "glbstate %02x:%s" FOURBITS "\n", tmp,
		(tmp & AT91_UDP_RMWUPE) ? " rmwupe" : "",
		(tmp & AT91_UDP_RSMINPR) ? " rsminpr" : "",
		(tmp & AT91_UDP_ESR) ? " esr" : "",
		(tmp & AT91_UDP_CONFG) ? " confg" : "",
		(tmp & AT91_UDP_FADDEN) ? " fadden" : "");

	tmp = at91_udp_read(udc, AT91_UDP_FADDR);
	seq_printf(s, "faddr   %03x:%s fadd=%d\n", tmp,
		(tmp & AT91_UDP_FEN) ? " fen" : "",
		(tmp & AT91_UDP_FADD));

	proc_irq_show(s, "imr   ", at91_udp_read(udc, AT91_UDP_IMR));
	proc_irq_show(s, "isr   ", at91_udp_read(udc, AT91_UDP_ISR));

	if (udc->enabled && udc->vbus) {
		proc_ep_show(s, &udc->ep[0]);
		list_for_each_entry (ep, &udc->gadget.ep_list, ep.ep_list) {
			if (ep->desc)
				proc_ep_show(s, ep);
		}
	}
	return 0;
}

static int proc_udc_open(struct inode *inode, struct file *file)
{
	return single_open(file, proc_udc_show, PDE(inode)->data);
}

static const struct file_operations proc_ops = {
	.open		= proc_udc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static void create_debug_file(struct at91_udc *udc)
{
	struct proc_dir_entry *pde;

	pde = create_proc_entry (debug_filename, 0, NULL);
	udc->pde = pde;
	if (pde == NULL)
		return;

	pde->proc_fops = &proc_ops;
	pde->data = udc;
}

static void remove_debug_file(struct at91_udc *udc)
{
	if (udc->pde)
		remove_proc_entry(debug_filename, NULL);
}

#else

static inline void create_debug_file(struct at91_udc *udc) {}
static inline void remove_debug_file(struct at91_udc *udc) {}

#endif


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

static void done(struct at91_ep *ep, struct at91_request *req, int status)
{
	unsigned	stopped = ep->stopped;
	struct at91_udc	*udc = ep->udc;

	list_del_init(&req->queue);
	if (req->req.status == -EINPROGRESS)
		req->req.status = status;
	else
		status = req->req.status;
	if (status && status != -ESHUTDOWN)
		VDBG("%s done %p, status %d\n", ep->ep.name, req, status);

	ep->stopped = 1;
	req->req.complete(&ep->ep, &req->req);
	ep->stopped = stopped;

	/* ep0 is always ready; other endpoints need a non-empty queue */
	if (list_empty(&ep->queue) && ep->int_mask != (1 << 0))
		at91_udp_write(udc, AT91_UDP_IDR, ep->int_mask);
}

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

/* bits indicating OUT fifo has data ready */
#define	RX_DATA_READY	(AT91_UDP_RX_DATA_BK0 | AT91_UDP_RX_DATA_BK1)

/*
 * Endpoint FIFO CSR bits have a mix of bits, making it unsafe to just write
 * back most of the value you just read (because of side effects, including
 * bits that may change after reading and before writing).
 *
 * Except when changing a specific bit, always write values which:
 *  - clear SET_FX bits (setting them could change something)
 *  - set CLR_FX bits (clearing them could change something)
 *
 * There are also state bits like FORCESTALL, EPEDS, DIR, and EPTYPE
 * that shouldn't normally be changed.
 *
 * NOTE at91sam9260 docs mention synch between UDPCK and MCK clock domains,
 * implying a need to wait for one write to complete (test relevant bits)
 * before starting the next write.  This shouldn't be an issue given how
 * infrequently we write, except maybe for write-then-read idioms.
 */
#define	SET_FX	(AT91_UDP_TXPKTRDY)
#define	CLR_FX	(RX_DATA_READY | AT91_UDP_RXSETUP \
		| AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)

/* pull OUT packet data from the endpoint's fifo */
static int read_fifo (struct at91_ep *ep, struct at91_request *req)
{
	u32 __iomem	*creg = ep->creg;
	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
	u32		csr;
	u8		*buf;
	unsigned int	count, bufferspace, is_done;

	buf = req->req.buf + req->req.actual;
	bufferspace = req->req.length - req->req.actual;

	/*
	 * there might be nothing to read if ep_queue() calls us,
	 * or if we already emptied both pingpong buffers
	 */
rescan:
	csr = __raw_readl(creg);
	if ((csr & RX_DATA_READY) == 0)
		return 0;

	count = (csr & AT91_UDP_RXBYTECNT) >> 16;
	if (count > ep->ep.maxpacket)
		count = ep->ep.maxpacket;
	if (count > bufferspace) {
		DBG("%s buffer overflow\n", ep->ep.name);
		req->req.status = -EOVERFLOW;
		count = bufferspace;
	}
	__raw_readsb(dreg, buf, count);

	/* release and swap pingpong mem bank */
	csr |= CLR_FX;
	if (ep->is_pingpong) {
		if (ep->fifo_bank == 0) {
			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
			ep->fifo_bank = 1;
		} else {
			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK1);
			ep->fifo_bank = 0;
		}
	} else
		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
	__raw_writel(csr, creg);

	req->req.actual += count;
	is_done = (count < ep->ep.maxpacket);
	if (count == bufferspace)
		is_done = 1;

	PACKET("%s %p out/%d%s\n", ep->ep.name, &req->req, count,
			is_done ? " (done)" : "");

	/*
	 * avoid extra trips through IRQ logic for packets already in
	 * the fifo ... maybe preventing an extra (expensive) OUT-NAK
	 */
	if (is_done)
		done(ep, req, 0);
	else if (ep->is_pingpong) {
		bufferspace -= count;
		buf += count;
		goto rescan;
	}

	return is_done;
}

/* load fifo for an IN packet */
static int write_fifo(struct at91_ep *ep, struct at91_request *req)
{
	u32 __iomem	*creg = ep->creg;
	u32		csr = __raw_readl(creg);
	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
	unsigned	total, count, is_last;

	/*
	 * TODO: allow for writing two packets to the fifo ... that'll
	 * reduce the amount of IN-NAKing, but probably won't affect
	 * throughput much.  (Unlike preventing OUT-NAKing!)
	 */

	/*
	 * If ep_queue() calls us, the queue is empty and possibly in
	 * odd states like TXCOMP not yet cleared (we do it, saving at
	 * least one IRQ) or the fifo not yet being free.  Those aren't
	 * issues normally (IRQ handler fast path).
	 */
	if (unlikely(csr & (AT91_UDP_TXCOMP | AT91_UDP_TXPKTRDY))) {
		if (csr & AT91_UDP_TXCOMP) {
			csr |= CLR_FX;
			csr &= ~(SET_FX | AT91_UDP_TXCOMP);
			__raw_writel(csr, creg);
			csr = __raw_readl(creg);
		}
		if (csr & AT91_UDP_TXPKTRDY)
			return 0;
	}

	total = req->req.length - req->req.actual;
	if (ep->ep.maxpacket < total) {
		count = ep->ep.maxpacket;
		is_last = 0;
	} else {
		count = total;
		is_last = (count < ep->ep.maxpacket) || !req->req.zero;
	}

	/*
	 * Write the packet, maybe it's a ZLP.
	 *
	 * NOTE:  incrementing req->actual before we receive the ACK means
	 * gadget driver IN bytecounts can be wrong in fault cases.  That's
	 * fixable with PIO drivers like this one (save "count" here, and
	 * do the increment later on TX irq), but not for most DMA hardware.
	 *
	 * So all gadget drivers must accept that potential error.  Some
	 * hardware supports precise fifo status reporting, letting them
	 * recover when the actual bytecount matters (e.g. for USB Test
	 * and Measurement Class devices).
	 */
	__raw_writesb(dreg, req->req.buf + req->req.actual, count);
	csr &= ~SET_FX;
	csr |= CLR_FX | AT91_UDP_TXPKTRDY;
	__raw_writel(csr, creg);
	req->req.actual += count;

	PACKET("%s %p in/%d%s\n", ep->ep.name, &req->req, count,
			is_last ? " (done)" : "");
	if (is_last)
		done(ep, req, 0);
	return is_last;
}

static void nuke(struct at91_ep *ep, int status)
{
	struct at91_request *req;

	// terminer chaque requete dans la queue
	ep->stopped = 1;
	if (list_empty(&ep->queue))
		return;

	VDBG("%s %s\n", __FUNCTION__, ep->ep.name);