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1/*
2 * SCR24x PCMCIA Smart Card Reader Driver
3 *
4 * Copyright (C) 2005-2006 TL Sudheendran
5 * Copyright (C) 2016 Lubomir Rintel
6 *
7 * Derived from "scr24x_v4.2.6_Release.tar.gz" driver by TL Sudheendran.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2, or (at your option)
12 * any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; see the file COPYING. If not, write to
21 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23
24#include <linux/device.h>
25#include <linux/module.h>
26#include <linux/delay.h>
27#include <linux/cdev.h>
28#include <linux/slab.h>
29#include <linux/fs.h>
30#include <linux/uaccess.h>
31
32#include <pcmcia/cistpl.h>
33#include <pcmcia/ds.h>
34
35#define CCID_HEADER_SIZE 10
36#define CCID_LENGTH_OFFSET 1
37#define CCID_MAX_LEN 271
38
39#define SCR24X_DATA(n) (1 + n)
40#define SCR24X_CMD_STATUS 7
41#define CMD_START 0x40
42#define CMD_WRITE_BYTE 0x41
43#define CMD_READ_BYTE 0x42
44#define STATUS_BUSY 0x80
45
46struct scr24x_dev {
47 struct device *dev;
48 struct cdev c_dev;
49 unsigned char buf[CCID_MAX_LEN];
50 int devno;
51 struct mutex lock;
52 struct kref refcnt;
53 u8 __iomem *regs;
54};
55
56#define SCR24X_DEVS 8
57static DECLARE_BITMAP(scr24x_minors, SCR24X_DEVS);
58
59static struct class *scr24x_class;
60static dev_t scr24x_devt;
61
62static void scr24x_delete(struct kref *kref)
63{
64 struct scr24x_dev *dev = container_of(kref, struct scr24x_dev,
65 refcnt);
66
67 kfree(dev);
68}
69
70static int scr24x_wait_ready(struct scr24x_dev *dev)
71{
72 u_char status;
73 int timeout = 100;
74
75 do {
76 status = ioread8(dev->regs + SCR24X_CMD_STATUS);
77 if (!(status & STATUS_BUSY))
78 return 0;
79
80 msleep(20);
81 } while (--timeout);
82
83 return -EIO;
84}
85
86static int scr24x_open(struct inode *inode, struct file *filp)
87{
88 struct scr24x_dev *dev = container_of(inode->i_cdev,
89 struct scr24x_dev, c_dev);
90
91 kref_get(&dev->refcnt);
92 filp->private_data = dev;
93
94 return nonseekable_open(inode, filp);
95}
96
97static int scr24x_release(struct inode *inode, struct file *filp)
98{
99 struct scr24x_dev *dev = filp->private_data;
100
101 /* We must not take the dev->lock here as scr24x_delete()
102 * might be called to remove the dev structure altogether.
103 * We don't need the lock anyway, since after the reference
104 * acquired in probe() is released in remove() the chrdev
105 * is already unregistered and noone can possibly acquire
106 * a reference via open() anymore. */
107 kref_put(&dev->refcnt, scr24x_delete);
108 return 0;
109}
110
111static int read_chunk(struct scr24x_dev *dev, size_t offset, size_t limit)
112{
113 size_t i, y;
114 int ret;
115
116 for (i = offset; i < limit; i += 5) {
117 iowrite8(CMD_READ_BYTE, dev->regs + SCR24X_CMD_STATUS);
118 ret = scr24x_wait_ready(dev);
119 if (ret < 0)
120 return ret;
121
122 for (y = 0; y < 5 && i + y < limit; y++)
123 dev->buf[i + y] = ioread8(dev->regs + SCR24X_DATA(y));
124 }
125
126 return 0;
127}
128
129static ssize_t scr24x_read(struct file *filp, char __user *buf, size_t count,
130 loff_t *ppos)
131{
132 struct scr24x_dev *dev = filp->private_data;
133 int ret;
134 int len;
135
136 if (count < CCID_HEADER_SIZE)
137 return -EINVAL;
138
139 if (mutex_lock_interruptible(&dev->lock))
140 return -ERESTARTSYS;
141
142 if (!dev->dev) {
143 ret = -ENODEV;
144 goto out;
145 }
146
147 ret = scr24x_wait_ready(dev);
148 if (ret < 0)
149 goto out;
150 len = CCID_HEADER_SIZE;
151 ret = read_chunk(dev, 0, len);
152 if (ret < 0)
153 goto out;
154
155 len += le32_to_cpu(*(__le32 *)(&dev->buf[CCID_LENGTH_OFFSET]));
156 if (len > sizeof(dev->buf)) {
157 ret = -EIO;
158 goto out;
159 }
160 read_chunk(dev, CCID_HEADER_SIZE, len);
161 if (ret < 0)
162 goto out;
163
164 if (len < count)
165 count = len;
166
167 if (copy_to_user(buf, dev->buf, count)) {
168 ret = -EFAULT;
169 goto out;
170 }
171
172 ret = count;
173out:
174 mutex_unlock(&dev->lock);
175 return ret;
176}
177
178static ssize_t scr24x_write(struct file *filp, const char __user *buf,
179 size_t count, loff_t *ppos)
180{
181 struct scr24x_dev *dev = filp->private_data;
182 size_t i, y;
183 int ret;
184
185 if (mutex_lock_interruptible(&dev->lock))
186 return -ERESTARTSYS;
187
188 if (!dev->dev) {
189 ret = -ENODEV;
190 goto out;
191 }
192
193 if (count > sizeof(dev->buf)) {
194 ret = -EINVAL;
195 goto out;
196 }
197
198 if (copy_from_user(dev->buf, buf, count)) {
199 ret = -EFAULT;
200 goto out;
201 }
202
203 ret = scr24x_wait_ready(dev);
204 if (ret < 0)
205 goto out;
206
207 iowrite8(CMD_START, dev->regs + SCR24X_CMD_STATUS);
208 ret = scr24x_wait_ready(dev);
209 if (ret < 0)
210 goto out;
211
212 for (i = 0; i < count; i += 5) {
213 for (y = 0; y < 5 && i + y < count; y++)
214 iowrite8(dev->buf[i + y], dev->regs + SCR24X_DATA(y));
215
216 iowrite8(CMD_WRITE_BYTE, dev->regs + SCR24X_CMD_STATUS);
217 ret = scr24x_wait_ready(dev);
218 if (ret < 0)
219 goto out;
220 }
221
222 ret = count;
223out:
224 mutex_unlock(&dev->lock);
225 return ret;
226}
227
228static const struct file_operations scr24x_fops = {
229 .owner = THIS_MODULE,
230 .read = scr24x_read,
231 .write = scr24x_write,
232 .open = scr24x_open,
233 .release = scr24x_release,
234 .llseek = no_llseek,
235};
236
237static int scr24x_config_check(struct pcmcia_device *link, void *priv_data)
238{
239 if (resource_size(link->resource[PCMCIA_IOPORT_0]) != 0x11)
240 return -ENODEV;
241 return pcmcia_request_io(link);
242}
243
244static int scr24x_probe(struct pcmcia_device *link)
245{
246 struct scr24x_dev *dev;
247 int ret;
248
249 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
250 if (!dev)
251 return -ENOMEM;
252
253 dev->devno = find_first_zero_bit(scr24x_minors, SCR24X_DEVS);
254 if (dev->devno >= SCR24X_DEVS) {
255 ret = -EBUSY;
256 goto err;
257 }
258
259 mutex_init(&dev->lock);
260 kref_init(&dev->refcnt);
261
262 link->priv = dev;
263 link->config_flags |= CONF_ENABLE_IRQ | CONF_AUTO_SET_IO;
264
265 ret = pcmcia_loop_config(link, scr24x_config_check, NULL);
266 if (ret < 0)
267 goto err;
268
269 dev->dev = &link->dev;
270 dev->regs = devm_ioport_map(&link->dev,
271 link->resource[PCMCIA_IOPORT_0]->start,
272 resource_size(link->resource[PCMCIA_IOPORT_0]));
273 if (!dev->regs) {
274 ret = -EIO;
275 goto err;
276 }
277
278 cdev_init(&dev->c_dev, &scr24x_fops);
279 dev->c_dev.owner = THIS_MODULE;
280 dev->c_dev.ops = &scr24x_fops;
281 ret = cdev_add(&dev->c_dev, MKDEV(MAJOR(scr24x_devt), dev->devno), 1);
282 if (ret < 0)
283 goto err;
284
285 ret = pcmcia_enable_device(link);
286 if (ret < 0) {
287 pcmcia_disable_device(link);
288 goto err;
289 }
290
291 device_create(scr24x_class, NULL, MKDEV(MAJOR(scr24x_devt), dev->devno),
292 NULL, "scr24x%d", dev->devno);
293
294 dev_info(&link->dev, "SCR24x Chip Card Interface\n");
295 return 0;
296
297err:
298 if (dev->devno < SCR24X_DEVS)
299 clear_bit(dev->devno, scr24x_minors);
300 kfree (dev);
301 return ret;
302}
303
304static void scr24x_remove(struct pcmcia_device *link)
305{
306 struct scr24x_dev *dev = (struct scr24x_dev *)link->priv;
307
308 device_destroy(scr24x_class, MKDEV(MAJOR(scr24x_devt), dev->devno));
309 mutex_lock(&dev->lock);
310 pcmcia_disable_device(link);
311 cdev_del(&dev->c_dev);
312 clear_bit(dev->devno, scr24x_minors);
313 dev->dev = NULL;
314 mutex_unlock(&dev->lock);
315
316 kref_put(&dev->refcnt, scr24x_delete);
317}
318
319static const struct pcmcia_device_id scr24x_ids[] = {
320 PCMCIA_DEVICE_PROD_ID12("HP", "PC Card Smart Card Reader",
321 0x53cb94f9, 0xbfdf89a5),
322 PCMCIA_DEVICE_PROD_ID1("SCR241 PCMCIA", 0x6271efa3),
323 PCMCIA_DEVICE_PROD_ID1("SCR243 PCMCIA", 0x2054e8de),
324 PCMCIA_DEVICE_PROD_ID1("SCR24x PCMCIA", 0x54a33665),
325 PCMCIA_DEVICE_NULL
326};
327MODULE_DEVICE_TABLE(pcmcia, scr24x_ids);
328
329static struct pcmcia_driver scr24x_driver = {
330 .owner = THIS_MODULE,
331 .name = "scr24x_cs",
332 .probe = scr24x_probe,
333 .remove = scr24x_remove,
334 .id_table = scr24x_ids,
335};
336
337static int __init scr24x_init(void)
338{
339 int ret;
340
341 scr24x_class = class_create(THIS_MODULE, "scr24x");
342 if (IS_ERR(scr24x_class))
343 return PTR_ERR(scr24x_class);
344
345 ret = alloc_chrdev_region(&scr24x_devt, 0, SCR24X_DEVS, "scr24x");
346 if (ret < 0) {
347 class_destroy(scr24x_class);
348 return ret;
349 }
350
351 ret = pcmcia_register_driver(&scr24x_driver);
352 if (ret < 0) {
353 unregister_chrdev_region(scr24x_devt, SCR24X_DEVS);
354 class_destroy(scr24x_class);
355 }
356
357 return ret;
358}
359
360static void __exit scr24x_exit(void)
361{
362 pcmcia_unregister_driver(&scr24x_driver);
363 unregister_chrdev_region(scr24x_devt, SCR24X_DEVS);
364 class_destroy(scr24x_class);
365}
366
367module_init(scr24x_init);
368module_exit(scr24x_exit);
369
370MODULE_AUTHOR("Lubomir Rintel");
371MODULE_DESCRIPTION("SCR24x PCMCIA Smart Card Reader Driver");
372MODULE_LICENSE("GPL");