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|
/*
* SCR24x PCMCIA Smart Card Reader Driver
*
* Copyright (C) 2005-2006 TL Sudheendran
* Copyright (C) 2016 Lubomir Rintel
*
* Derived from "scr24x_v4.2.6_Release.tar.gz" driver by TL Sudheendran.
*
* 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, 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; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/ds.h>
#define CCID_HEADER_SIZE 10
#define CCID_LENGTH_OFFSET 1
#define CCID_MAX_LEN 271
#define SCR24X_DATA(n) (1 + n)
#define SCR24X_CMD_STATUS 7
#define CMD_START 0x40
#define CMD_WRITE_BYTE 0x41
#define CMD_READ_BYTE 0x42
#define STATUS_BUSY 0x80
struct scr24x_dev {
struct device *dev;
struct cdev c_dev;
unsigned char buf[CCID_MAX_LEN];
int devno;
struct mutex lock;
struct kref refcnt;
u8 __iomem *regs;
};
#define SCR24X_DEVS 8
static DECLARE_BITMAP(scr24x_minors, SCR24X_DEVS);
static struct class *scr24x_class;
static dev_t scr24x_devt;
static void scr24x_delete(struct kref *kref)
{
struct scr24x_dev *dev = container_of(kref, struct scr24x_dev,
refcnt);
kfree(dev);
}
static int scr24x_wait_ready(struct scr24x_dev *dev)
{
u_char status;
int timeout = 100;
do {
status = ioread8(dev->regs + SCR24X_CMD_STATUS);
if (!(status & STATUS_BUSY))
return 0;
msleep(20);
} while (--timeout);
return -EIO;
}
static int scr24x_open(struct inode *inode, struct file *filp)
{
struct scr24x_dev *dev = container_of(inode->i_cdev,
struct scr24x_dev, c_dev);
kref_get(&dev->refcnt);
filp->private_data = dev;
return nonseekable_open(inode, filp);
}
static int scr24x_release(struct inode *inode, struct file *filp)
{
struct scr24x_dev *dev = filp->private_data;
/* We must not take the dev->lock here as scr24x_delete()
* might be called to remove the dev structure altogether.
* We don't need the lock anyway, since after the reference
* acquired in probe() is released in remove() the chrdev
* is already unregistered and noone can possibly acquire
* a reference via open() anymore. */
kref_put(&dev->refcnt, scr24x_delete);
return 0;
}
static int read_chunk(struct scr24x_dev *dev, size_t offset, size_t limit)
{
size_t i, y;
int ret;
for (i = offset; i < limit; i += 5) {
iowrite8(CMD_READ_BYTE, dev->regs + SCR24X_CMD_STATUS);
ret = scr24x_wait_ready(dev);
if (ret < 0)
return ret;
for (y = 0; y < 5 && i + y < limit; y++)
dev->buf[i + y] = ioread8(dev->regs + SCR24X_DATA(y));
}
return 0;
}
static ssize_t scr24x_read(struct file *filp, char __user *buf, size_t count,
loff_t *ppos)
{
struct scr24x_dev *dev = filp->private_data;
int ret;
int len;
if (count < CCID_HEADER_SIZE)
return -EINVAL;
if (mutex_lock_interruptible(&dev->lock))
return -ERESTARTSYS;
if (!dev->dev) {
ret = -ENODEV;
goto out;
}
ret = scr24x_wait_ready(dev);
if (ret < 0)
goto out;
len = CCID_HEADER_SIZE;
ret = read_chunk(dev, 0, len);
if (ret < 0)
goto out;
len += le32_to_cpu(*(__le32 *)(&dev->buf[CCID_LENGTH_OFFSET]));
if (len > sizeof(dev->buf)) {
ret = -EIO;
goto out;
}
ret = read_chunk(dev, CCID_HEADER_SIZE, len);
if (ret < 0)
goto out;
if (len < count)
count = len;
if (copy_to_user(buf, dev->buf, count)) {
ret = -EFAULT;
goto out;
}
ret = count;
out:
mutex_unlock(&dev->lock);
return ret;
}
static ssize_t scr24x_write(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos)
{
struct scr24x_dev *dev = filp->private_data;
size_t i, y;
int ret;
if (mutex_lock_interruptible(&dev->lock))
return -ERESTARTSYS;
if (!dev->dev) {
ret = -ENODEV;
goto out;
}
if (count > sizeof(dev->buf)) {
ret = -EINVAL;
goto out;
}
if (copy_from_user(dev->buf, buf, count)) {
ret = -EFAULT;
goto out;
}
ret = scr24x_wait_ready(dev);
if (ret < 0)
goto out;
iowrite8(CMD_START, dev->regs + SCR24X_CMD_STATUS);
ret = scr24x_wait_ready(dev);
if (ret < 0)
goto out;
for (i = 0; i < count; i += 5) {
for (y = 0; y < 5 && i + y < count; y++)
iowrite8(dev->buf[i + y], dev->regs + SCR24X_DATA(y));
iowrite8(CMD_WRITE_BYTE, dev->regs + SCR24X_CMD_STATUS);
ret = scr24x_wait_ready(dev);
if (ret < 0)
goto out;
}
ret = count;
out:
mutex_unlock(&dev->lock);
return ret;
}
static const struct file_operations scr24x_fops = {
.owner = THIS_MODULE,
.read = scr24x_read,
.write = scr24x_write,
.open = scr24x_open,
.release = scr24x_release,
.llseek = no_llseek,
};
static int scr24x_config_check(struct pcmcia_device *link, void *priv_data)
{
if (resource_size(link->resource[PCMCIA_IOPORT_0]) != 0x11)
return -ENODEV;
return pcmcia_request_io(link);
}
static int scr24x_probe(struct pcmcia_device *link)
{
struct scr24x_dev *dev;
int ret;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
dev->devno = find_first_zero_bit(scr24x_minors, SCR24X_DEVS);
if (dev->devno >= SCR24X_DEVS) {
ret = -EBUSY;
goto err;
}
mutex_init(&dev->lock);
kref_init(&dev->refcnt);
link->priv = dev;
link->config_flags |= CONF_ENABLE_IRQ | CONF_AUTO_SET_IO;
ret = pcmcia_loop_config(link, scr24x_config_check, NULL);
if (ret < 0)
goto err;
dev->dev = &link->dev;
dev->regs = devm_ioport_map(&link->dev,
link->resource[PCMCIA_IOPORT_0]->start,
resource_size(link->resource[PCMCIA_IOPORT_0]));
if (!dev->regs) {
ret = -EIO;
goto err;
}
cdev_init(&am
|