atmel_usba_udc.c

linux 内核源代码

/*
 * Driver for the Atmel USBA high speed USB device controller
 *
 * Copyright (C) 2005-2007 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/platform_device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/delay.h>

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

#include "atmel_usba_udc.h"


static struct usba_udc the_udc;

#ifdef CONFIG_USB_GADGET_DEBUG_FS
#include <linux/debugfs.h>
#include <linux/uaccess.h>

static int queue_dbg_open(struct inode *inode, struct file *file)
{
	struct usba_ep *ep = inode->i_private;
	struct usba_request *req, *req_copy;
	struct list_head *queue_data;

	queue_data = kmalloc(sizeof(*queue_data), GFP_KERNEL);
	if (!queue_data)
		return -ENOMEM;
	INIT_LIST_HEAD(queue_data);

	spin_lock_irq(&ep->udc->lock);
	list_for_each_entry(req, &ep->queue, queue) {
		req_copy = kmalloc(sizeof(*req_copy), GFP_ATOMIC);
		if (!req_copy)
			goto fail;
		memcpy(req_copy, req, sizeof(*req_copy));
		list_add_tail(&req_copy->queue, queue_data);
	}
	spin_unlock_irq(&ep->udc->lock);

	file->private_data = queue_data;
	return 0;

fail:
	spin_unlock_irq(&ep->udc->lock);
	list_for_each_entry_safe(req, req_copy, queue_data, queue) {
		list_del(&req->queue);
		kfree(req);
	}
	kfree(queue_data);
	return -ENOMEM;
}

/*
 * bbbbbbbb llllllll IZS sssss nnnn FDL\n\0
 *
 * b: buffer address
 * l: buffer length
 * I/i: interrupt/no interrupt
 * Z/z: zero/no zero
 * S/s: short ok/short not ok
 * s: status
 * n: nr_packets
 * F/f: submitted/not submitted to FIFO
 * D/d: using/not using DMA
 * L/l: last transaction/not last transaction
 */
static ssize_t queue_dbg_read(struct file *file, char __user *buf,
		size_t nbytes, loff_t *ppos)
{
	struct list_head *queue = file->private_data;
	struct usba_request *req, *tmp_req;
	size_t len, remaining, actual = 0;
	char tmpbuf[38];

	if (!access_ok(VERIFY_WRITE, buf, nbytes))
		return -EFAULT;

	mutex_lock(&file->f_dentry->d_inode->i_mutex);
	list_for_each_entry_safe(req, tmp_req, queue, queue) {
		len = snprintf(tmpbuf, sizeof(tmpbuf),
				"%8p %08x %c%c%c %5d %c%c%c\n",
				req->req.buf, req->req.length,
				req->req.no_interrupt ? 'i' : 'I',
				req->req.zero ? 'Z' : 'z',
				req->req.short_not_ok ? 's' : 'S',
				req->req.status,
				req->submitted ? 'F' : 'f',
				req->using_dma ? 'D' : 'd',
				req->last_transaction ? 'L' : 'l');
		len = min(len, sizeof(tmpbuf));
		if (len > nbytes)
			break;

		list_del(&req->queue);
		kfree(req);

		remaining = __copy_to_user(buf, tmpbuf, len);
		actual += len - remaining;
		if (remaining)
			break;

		nbytes -= len;
		buf += len;
	}
	mutex_unlock(&file->f_dentry->d_inode->i_mutex);

	return actual;
}

static int queue_dbg_release(struct inode *inode, struct file *file)
{
	struct list_head *queue_data = file->private_data;
	struct usba_request *req, *tmp_req;

	list_for_each_entry_safe(req, tmp_req, queue_data, queue) {
		list_del(&req->queue);
		kfree(req);
	}
	kfree(queue_data);
	return 0;
}

static int regs_dbg_open(struct inode *inode, struct file *file)
{
	struct usba_udc *udc;
	unsigned int i;
	u32 *data;
	int ret = -ENOMEM;

	mutex_lock(&inode->i_mutex);
	udc = inode->i_private;
	data = kmalloc(inode->i_size, GFP_KERNEL);
	if (!data)
		goto out;

	spin_lock_irq(&udc->lock);
	for (i = 0; i < inode->i_size / 4; i++)
		data[i] = __raw_readl(udc->regs + i * 4);
	spin_unlock_irq(&udc->lock);

	file->private_data = data;
	ret = 0;

out:
	mutex_unlock(&inode->i_mutex);

	return ret;
}

static ssize_t regs_dbg_read(struct file *file, char __user *buf,
		size_t nbytes, loff_t *ppos)
{
	struct inode *inode = file->f_dentry->d_inode;
	int ret;

	mutex_lock(&inode->i_mutex);
	ret = simple_read_from_buffer(buf, nbytes, ppos,
			file->private_data,
			file->f_dentry->d_inode->i_size);
	mutex_unlock(&inode->i_mutex);

	return ret;
}

static int regs_dbg_release(struct inode *inode, struct file *file)
{
	kfree(file->private_data);
	return 0;
}

const struct file_operations queue_dbg_fops = {
	.owner		= THIS_MODULE,
	.open		= queue_dbg_open,
	.llseek		= no_llseek,
	.read		= queue_dbg_read,
	.release	= queue_dbg_release,
};

const struct file_operations regs_dbg_fops = {
	.owner		= THIS_MODULE,
	.open		= regs_dbg_open,
	.llseek		= generic_file_llseek,
	.read		= regs_dbg_read,
	.release	= regs_dbg_release,
};

static void usba_ep_init_debugfs(struct usba_udc *udc,
		struct usba_ep *ep)
{
	struct dentry *ep_root;

	ep_root = debugfs_create_dir(ep->ep.name, udc->debugfs_root);
	if (!ep_root)
		goto err_root;
	ep->debugfs_dir = ep_root;

	ep->debugfs_queue = debugfs_create_file("queue", 0400, ep_root,
						ep, &queue_dbg_fops);
	if (!ep->debugfs_queue)
		goto err_queue;

	if (ep->can_dma) {
		ep->debugfs_dma_status
			= debugfs_create_u32("dma_status", 0400, ep_root,
					&ep->last_dma_status);
		if (!ep->debugfs_dma_status)
			goto err_dma_status;
	}
	if (ep_is_control(ep)) {
		ep->debugfs_state
			= debugfs_create_u32("state", 0400, ep_root,
					&ep->state);
		if (!ep->debugfs_state)
			goto err_state;
	}

	return;

err_state:
	if (ep->can_dma)
		debugfs_remove(ep->debugfs_dma_status);
err_dma_status:
	debugfs_remove(ep->debugfs_queue);
err_queue:
	debugfs_remove(ep_root);
err_root:
	dev_err(&ep->udc->pdev->dev,
		"failed to create debugfs directory for %s\n", ep->ep.name);
}

static void usba_ep_cleanup_debugfs(struct usba_ep *ep)
{
	debugfs_remove(ep->debugfs_queue);
	debugfs_remove(ep->debugfs_dma_status);
	debugfs_remove(ep->debugfs_state);
	debugfs_remove(ep->debugfs_dir);
	ep->debugfs_dma_status = NULL;
	ep->debugfs_dir = NULL;
}

static void usba_init_debugfs(struct usba_udc *udc)
{
	struct dentry *root, *regs;
	struct resource *regs_resource;

	root = debugfs_create_dir(udc->gadget.name, NULL);
	if (IS_ERR(root) || !root)
		goto err_root;
	udc->debugfs_root = root;

	regs = debugfs_create_file("regs", 0400, root, udc, &regs_dbg_fops);
	if (!regs)
		goto err_regs;

	regs_resource = platform_get_resource(udc->pdev, IORESOURCE_MEM,
				CTRL_IOMEM_ID);
	regs->d_inode->i_size = regs_resource->end - regs_resource->start + 1;
	udc->debugfs_regs = regs;

	usba_ep_init_debugfs(udc, to_usba_ep(udc->gadget.ep0));

	return;

err_regs:
	debugfs_remove(root);
err_root:
	udc->debugfs_root = NULL;
	dev_err(&udc->pdev->dev, "debugfs is not available\n");
}

static void usba_cleanup_debugfs(struct usba_udc *udc)
{
	usba_ep_cleanup_debugfs(to_usba_ep(udc->gadget.ep0));
	debugfs_remove(udc->debugfs_regs);
	debugfs_remove(udc->debugfs_root);
	udc->debugfs_regs = NULL;
	udc->debugfs_root = NULL;
}
#else
static inline void usba_ep_init_debugfs(struct usba_udc *udc,
					 struct usba_ep *ep)
{

}

static inline void usba_ep_cleanup_debugfs(struct usba_ep *ep)
{

}

static inline void usba_init_debugfs(struct usba_udc *udc)
{

}

static inline void usba_cleanup_debugfs(struct usba_udc *udc)
{

}
#endif

static int vbus_is_present(struct usba_udc *udc)
{
	if (udc->vbus_pin != -1)
		return gpio_get_value(udc->vbus_pin);

	/* No Vbus detection: Assume always present */
	return 1;
}

static void copy_to_fifo(void __iomem *fifo, const void *buf, int len)
{
	unsigned long tmp;

	DBG(DBG_FIFO, "copy to FIFO (len %d):\n", len);
	for (; len > 0; len -= 4, buf += 4, fifo += 4) {
		tmp = *(unsigned long *)buf;
		if (len >= 4) {
			DBG(DBG_FIFO, "  -> %08lx\n", tmp);
			__raw_writel(tmp, fifo);
		} else {
			do {
				DBG(DBG_FIFO, "  -> %02lx\n", tmp >> 24);
				__raw_writeb(tmp >> 24, fifo);
				fifo++;
				tmp <<= 8;
			} while (--len);
			break;
		}
	}
}

static void copy_from_fifo(void *buf, void __iomem *fifo, int len)
{
	union {
		unsigned long *w;
		unsigned char *b;
	} p;
	unsigned long tmp;

	DBG(DBG_FIFO, "copy from FIFO (len %d):\n", len);
	for (p.w = buf; len > 0; len -= 4, p.w++, fifo += 4) {
		if (len >= 4) {
			tmp = __raw_readl(fifo);
			*p.w = tmp;
			DBG(DBG_FIFO, "  -> %08lx\n", tmp);
		} else {
			do {
				tmp = __raw_readb(fifo);
				*p.b = tmp;
				DBG(DBG_FIFO, " -> %02lx\n", tmp);
				fifo++, p.b++;
			} while (--len);
		}
	}
}

static void next_fifo_transaction(struct usba_ep *ep, struct usba_request *req)
{
	unsigned int transaction_len;

	transaction_len = req->req.length - req->req.actual;
	req->last_transaction = 1;
	if (transaction_len > ep->ep.maxpacket) {
		transaction_len = ep->ep.maxpacket;
		req->last_transaction = 0;
	} else if (transaction_len == ep->ep.maxpacket && req->req.zero)
		req->last_transaction = 0;

	DBG(DBG_QUEUE, "%s: submit_transaction, req %p (length %d)%s\n",
		ep->ep.name, req, transaction_len,
		req->last_transaction ? ", done" : "");

	copy_to_fifo(ep->fifo, req->req.buf + req->req.actual, transaction_len);
	usba_ep_writel(ep, SET_STA, USBA_TX_PK_RDY);
	req->req.actual += transaction_len;
}

static void submit_request(struct usba_ep *ep, struct usba_request *req)
{
	DBG(DBG_QUEUE, "%s: submit_request: req %p (length %d)\n",
		ep->ep.name, req, req->req.length);

	req->req.actual = 0;
	req->submitted = 1;

	if (req->using_dma) {
		if (req->req.length == 0) {
			usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY);
			return;
		}

		if (req->req.zero)
			usba_ep_writel(ep, CTL_ENB, USBA_SHORT_PACKET);
		else
			usba_ep_writel(ep, CTL_DIS, USBA_SHORT_PACKET);

		usba_dma_writel(ep, ADDRESS, req->req.dma);
		usba_dma_writel(ep, CONTROL, req->ctrl);
	} else {
		next_fifo_transaction(ep, req);
		if (req->last_transaction) {
			usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY);
			usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE);
		} else {
			usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
			usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY);
		}
	}
}

static void submit_next_request(struct usba_ep *ep)
{
	struct usba_request *req;

	if (list_empty(&ep->queue)) {
		usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY | USBA_RX_BK_RDY);
		return;
	}

	req = list_entry(ep->queue.next, struct usba_request, queue);
	if (!req->submitted)
		submit_request(ep, req);
}

static void send_status(struct usba_udc *udc, struct usba_ep *ep)
{
	ep->state = STATUS_STAGE_IN;
	usba_ep_writel(ep, SET_STA, USBA_TX_PK_RDY);
	usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE);
}

static void receive_data(struct usba_ep *ep)
{
	struct usba_udc *udc = ep->udc;
	struct usba_request *req;
	unsigned long status;
	unsigned int bytecount, nr_busy;
	int is_complete = 0;

	status = usba_ep_readl(ep, STA);
	nr_busy = USBA_BFEXT(BUSY_BANKS, status);

	DBG(DBG_QUEUE, "receive data: nr_busy=%u\n", nr_busy);

	while (nr_busy > 0) {
		if (list_empty(&ep->queue)) {
			usba_ep_writel(ep, CTL_DIS, USBA_RX_BK_RDY);
			break;
		}
		req = list_entry(ep->queue.next,
				 struct usba_request, queue);

		bytecount = USBA_BFEXT(BYTE_COUNT, status);

		if (status & (1 << 31))
			is_complete = 1;
		if (req->req.actual + bytecount >= req->req.length) {
			is_complete = 1;
			bytecount = req->req.length - req->req.actual;
		}

		copy_from_fifo(req->req.buf + req->req.actual,
				ep->fifo, bytecount);
		req->req.actual += bytecount;

		usba_ep_writel(ep, CLR_STA, USBA_RX_BK_RDY);

		if (is_complete) {
			DBG(DBG_QUEUE, "%s: request done\n", ep->ep.name);
			req->req.status = 0;
			list_del_init(&req->queue);
			usba_ep_writel(ep, CTL_DIS, USBA_RX_BK_RDY);
			spin_unlock(&udc->lock);
			req->req.complete(&ep->ep, &req->req);
			spin_lock(&udc->lock);
		}

		status = usba_ep_readl(ep, STA);
		nr_busy = USBA_BFEXT(BUSY_BANKS, status);

		if (is_complete && ep_is_control(ep)) {
			send_status(udc, ep);
			break;
		}
	}
}

static void
request_complete(struct usba_ep *ep, struct usba_request *req, int status)
{
	struct usba_udc *udc = ep->udc;

	WARN_ON(!list_empty(&req->queue));

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

	if (req->mapped) {
		dma_unmap_single(
			&udc->pdev->dev, req->req.dma, req->req.length,
			ep->is_in ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
		req->req.dma = DMA_ADDR_INVALID;
		req->mapped = 0;