2 pg.c (c) 1998 Grant R. Guenther <grant@torque.net>
3 Under the terms of the GNU General Public License.
5 The pg driver provides a simple character device interface for
6 sending ATAPI commands to a device. With the exception of the
7 ATAPI reset operation, all operations are performed by a pair
8 of read and write operations to the appropriate /dev/pgN device.
9 A write operation delivers a command and any outbound data in
10 a single buffer. Normally, the write will succeed unless the
11 device is offline or malfunctioning, or there is already another
12 command pending. If the write succeeds, it should be followed
13 immediately by a read operation, to obtain any returned data and
14 status information. A read will fail if there is no operation
17 As a special case, the device can be reset with a write operation,
18 and in this case, no following read is expected, or permitted.
20 There are no ioctl() operations. Any single operation
21 may transfer at most PG_MAX_DATA bytes. Note that the driver must
22 copy the data through an internal buffer. In keeping with all
23 current ATAPI devices, command packets are assumed to be exactly
26 To permit future changes to this interface, the headers in the
27 read and write buffers contain a single character "magic" flag.
28 Currently this flag must be the character "P".
30 By default, the driver will autoprobe for a single parallel
31 port ATAPI device, but if their individual parameters are
32 specified, the driver can handle up to 4 devices.
34 To use this device, you must have the following device
35 special files defined:
42 (You'll need to change the 97 to something else if you use
43 the 'major' parameter to install the driver on a different
46 The behaviour of the pg driver can be altered by setting
47 some parameters from the insmod command line. The following
48 parameters are adjustable:
50 drive0 These four arguments can be arrays of
51 drive1 1-6 integers as follows:
53 drive3 <prt>,<pro>,<uni>,<mod>,<slv>,<dly>
57 <prt> is the base of the parallel port address for
58 the corresponding drive. (required)
60 <pro> is the protocol number for the adapter that
61 supports this drive. These numbers are
62 logged by 'paride' when the protocol modules
63 are initialised. (0 if not given)
65 <uni> for those adapters that support chained
66 devices, this is the unit selector for the
67 chain of devices on the given port. It should
68 be zero for devices that don't support chaining.
71 <mod> this can be -1 to choose the best mode, or one
72 of the mode numbers supported by the adapter.
75 <slv> ATAPI devices can be jumpered to master or slave.
76 Set this to 0 to choose the master drive, 1 to
77 choose the slave, -1 (the default) to choose the
80 <dly> some parallel ports require the driver to
81 go more slowly. -1 sets a default value that
82 should work with the chosen protocol. Otherwise,
83 set this to a small integer, the larger it is
84 the slower the port i/o. In some cases, setting
85 this to zero will speed up the device. (default -1)
87 major You may use this parameter to overide the
88 default major number (97) that this driver
89 will use. Be sure to change the device
92 name This parameter is a character string that
93 contains the name the kernel will use for this
94 device (in /proc output, for instance).
97 verbose This parameter controls the amount of logging
98 that is done by the driver. Set it to 0 for
99 quiet operation, to 1 to enable progress
100 messages while the driver probes for devices,
101 or to 2 for full debug logging. (default 0)
103 If this driver is built into the kernel, you can use
104 the following command line parameters, with the same values
105 as the corresponding module parameters listed above:
112 In addition, you can use the parameter pg.disable to disable
119 1.01 GRG 1998.06.16 Bug fixes
120 1.02 GRG 1998.09.24 Added jumbo support
124 #define PG_VERSION "1.02"
133 /* Here are things one can override from the insmod command.
134 Most are autoprobed by paride unless set here. Verbose is 0
139 static int verbose = 0;
140 static int major = PG_MAJOR;
141 static char *name = PG_NAME;
142 static int disable = 0;
144 static int drive0[6] = { 0, 0, 0, -1, -1, -1 };
145 static int drive1[6] = { 0, 0, 0, -1, -1, -1 };
146 static int drive2[6] = { 0, 0, 0, -1, -1, -1 };
147 static int drive3[6] = { 0, 0, 0, -1, -1, -1 };
149 static int (*drives[4])[6] = {&drive0, &drive1, &drive2, &drive3};
150 static int pg_drive_count;
152 enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_DLY};
154 /* end of parameters */
156 #include <linux/module.h>
157 #include <linux/init.h>
158 #include <linux/fs.h>
159 #include <linux/delay.h>
160 #include <linux/slab.h>
161 #include <linux/mtio.h>
162 #include <linux/pg.h>
163 #include <linux/device.h>
164 #include <linux/sched.h> /* current, TASK_* */
165 #include <linux/mutex.h>
166 #include <linux/jiffies.h>
168 #include <asm/uaccess.h>
170 module_param(verbose, bool, 0644);
171 module_param(major, int, 0);
172 module_param(name, charp, 0);
173 module_param_array(drive0, int, NULL, 0);
174 module_param_array(drive1, int, NULL, 0);
175 module_param_array(drive2, int, NULL, 0);
176 module_param_array(drive3, int, NULL, 0);
180 #define PG_SPIN_DEL 50 /* spin delay in micro-seconds */
183 #define PG_RESET_TMO 10*HZ
185 #define STAT_ERR 0x01
186 #define STAT_INDEX 0x02
187 #define STAT_ECC 0x04
188 #define STAT_DRQ 0x08
189 #define STAT_SEEK 0x10
190 #define STAT_WRERR 0x20
191 #define STAT_READY 0x40
192 #define STAT_BUSY 0x80
194 #define ATAPI_IDENTIFY 0x12
196 static DEFINE_MUTEX(pg_mutex);
197 static int pg_open(struct inode *inode, struct file *file);
198 static int pg_release(struct inode *inode, struct file *file);
199 static ssize_t pg_read(struct file *filp, char __user *buf,
200 size_t count, loff_t * ppos);
201 static ssize_t pg_write(struct file *filp, const char __user *buf,
202 size_t count, loff_t * ppos);
203 static int pg_detect(void);
208 struct pi_adapter pia; /* interface to paride layer */
209 struct pi_adapter *pi;
210 int busy; /* write done, read expected */
211 int start; /* jiffies at command start */
212 int dlen; /* transfer size requested */
213 unsigned long timeout; /* timeout requested */
214 int status; /* last sense key */
215 int drive; /* drive */
216 unsigned long access; /* count of active opens ... */
217 int present; /* device present ? */
219 char name[PG_NAMELEN]; /* pg0, pg1, ... */
222 static struct pg devices[PG_UNITS];
224 static int pg_identify(struct pg *dev, int log);
226 static char pg_scratch[512]; /* scratch block buffer */
228 static struct class *pg_class;
230 /* kernel glue structures */
232 static const struct file_operations pg_fops = {
233 .owner = THIS_MODULE,
237 .release = pg_release,
240 static void pg_init_units(void)
245 for (unit = 0; unit < PG_UNITS; unit++) {
246 int *parm = *drives[unit];
247 struct pg *dev = &devices[unit];
249 clear_bit(0, &dev->access);
253 dev->drive = parm[D_SLV];
254 snprintf(dev->name, PG_NAMELEN, "%s%c", name, 'a'+unit);
260 static inline int status_reg(struct pg *dev)
262 return pi_read_regr(dev->pi, 1, 6);
265 static inline int read_reg(struct pg *dev, int reg)
267 return pi_read_regr(dev->pi, 0, reg);
270 static inline void write_reg(struct pg *dev, int reg, int val)
272 pi_write_regr(dev->pi, 0, reg, val);
275 static inline u8 DRIVE(struct pg *dev)
277 return 0xa0+0x10*dev->drive;
280 static void pg_sleep(int cs)
282 schedule_timeout_interruptible(cs);
285 static int pg_wait(struct pg *dev, int go, int stop, unsigned long tmo, char *msg)
287 int j, r, e, s, p, to;
292 while ((((r = status_reg(dev)) & go) || (stop && (!(r & stop))))
293 && time_before(jiffies, tmo)) {
300 to = time_after_eq(jiffies, tmo);
302 if ((r & (STAT_ERR & stop)) || to) {
303 s = read_reg(dev, 7);
304 e = read_reg(dev, 1);
305 p = read_reg(dev, 2);
307 printk("%s: %s: stat=0x%x err=0x%x phase=%d%s\n",
308 dev->name, msg, s, e, p, to ? " timeout" : "");
311 dev->status = (e >> 4) & 0xff;
317 static int pg_command(struct pg *dev, char *cmd, int dlen, unsigned long tmo)
323 write_reg(dev, 6, DRIVE(dev));
325 if (pg_wait(dev, STAT_BUSY | STAT_DRQ, 0, tmo, "before command"))
328 write_reg(dev, 4, dlen % 256);
329 write_reg(dev, 5, dlen / 256);
330 write_reg(dev, 7, 0xa0); /* ATAPI packet command */
332 if (pg_wait(dev, STAT_BUSY, STAT_DRQ, tmo, "command DRQ"))
335 if (read_reg(dev, 2) != 1) {
336 printk("%s: command phase error\n", dev->name);
340 pi_write_block(dev->pi, cmd, 12);
343 printk("%s: Command sent, dlen=%d packet= ", dev->name, dlen);
344 for (k = 0; k < 12; k++)
345 printk("%02x ", cmd[k] & 0xff);
350 pi_disconnect(dev->pi);
354 static int pg_completion(struct pg *dev, char *buf, unsigned long tmo)
358 r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
363 while (read_reg(dev, 7) & STAT_DRQ) {
364 d = (read_reg(dev, 4) + 256 * read_reg(dev, 5));
365 n = ((d + 3) & 0xfffc);
366 p = read_reg(dev, 2) & 3;
368 pi_write_block(dev->pi, buf, n);
370 pi_read_block(dev->pi, buf, n);
372 printk("%s: %s %d bytes\n", dev->name,
373 p ? "Read" : "Write", n);
374 dev->dlen += (1 - p) * d;
376 r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
380 pi_disconnect(dev->pi);
385 static int pg_reset(struct pg *dev)
388 int expect[5] = { 1, 1, 1, 0x14, 0xeb };
392 write_reg(dev, 6, DRIVE(dev));
393 write_reg(dev, 7, 8);
395 pg_sleep(20 * HZ / 1000);
398 while ((k++ < PG_RESET_TMO) && (status_reg(dev) & STAT_BUSY))
401 for (i = 0; i < 5; i++)
402 got[i] = read_reg(dev, i + 1);
404 err = memcmp(expect, got, sizeof(got)) ? -1 : 0;
407 printk("%s: Reset (%d) signature = ", dev->name, k);
408 for (i = 0; i < 5; i++)
409 printk("%3x", got[i]);
411 printk(" (incorrect)");
415 pi_disconnect(dev->pi);
419 static void xs(char *buf, char *targ, int len)
424 for (k = 0; k < len; k++) {
426 if (c != ' ' && c != l)
434 static int pg_identify(struct pg *dev, int log)
437 char *ms[2] = { "master", "slave" };
439 char id_cmd[12] = { ATAPI_IDENTIFY, 0, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0 };
442 s = pg_command(dev, id_cmd, 36, jiffies + PG_TMO);
445 s = pg_completion(dev, buf, jiffies + PG_TMO);
451 xs(buf + 16, id, 16);
452 printk("%s: %s %s, %s\n", dev->name, mf, id, ms[dev->drive]);
459 * returns 0, with id set if drive is detected
460 * -1, if drive detection failed
462 static int pg_probe(struct pg *dev)
464 if (dev->drive == -1) {
465 for (dev->drive = 0; dev->drive <= 1; dev->drive++)
467 return pg_identify(dev, 1);
470 return pg_identify(dev, 1);
475 static int pg_detect(void)
477 struct pg *dev = &devices[0];
480 printk("%s: %s version %s, major %d\n", name, name, PG_VERSION, major);
483 if (pg_drive_count == 0) {
484 if (pi_init(dev->pi, 1, -1, -1, -1, -1, -1, pg_scratch,
485 PI_PG, verbose, dev->name)) {
486 if (!pg_probe(dev)) {
494 for (unit = 0; unit < PG_UNITS; unit++, dev++) {
495 int *parm = *drives[unit];
498 if (pi_init(dev->pi, 0, parm[D_PRT], parm[D_MOD],
499 parm[D_UNI], parm[D_PRO], parm[D_DLY],
500 pg_scratch, PI_PG, verbose, dev->name)) {
501 if (!pg_probe(dev)) {
512 printk("%s: No ATAPI device detected\n", name);
516 static int pg_open(struct inode *inode, struct file *file)
518 int unit = iminor(inode) & 0x7f;
519 struct pg *dev = &devices[unit];
522 mutex_lock(&pg_mutex);
523 if ((unit >= PG_UNITS) || (!dev->present)) {
528 if (test_and_set_bit(0, &dev->access)) {
538 pg_identify(dev, (verbose > 1));
540 dev->bufptr = kmalloc(PG_MAX_DATA, GFP_KERNEL);
541 if (dev->bufptr == NULL) {
542 clear_bit(0, &dev->access);
543 printk("%s: buffer allocation failed\n", dev->name);
548 file->private_data = dev;
551 mutex_unlock(&pg_mutex);
555 static int pg_release(struct inode *inode, struct file *file)
557 struct pg *dev = file->private_data;
561 clear_bit(0, &dev->access);
566 static ssize_t pg_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos)
568 struct pg *dev = filp->private_data;
569 struct pg_write_hdr hdr;
570 int hs = sizeof (hdr);
577 if (copy_from_user(&hdr, buf, hs))
580 if (hdr.magic != PG_MAGIC)
582 if (hdr.dlen > PG_MAX_DATA)
584 if ((count - hs) > PG_MAX_DATA)
587 if (hdr.func == PG_RESET) {
595 if (hdr.func != PG_COMMAND)
598 dev->start = jiffies;
599 dev->timeout = hdr.timeout * HZ + HZ / 2 + jiffies;
601 if (pg_command(dev, hdr.packet, hdr.dlen, jiffies + PG_TMO)) {
602 if (dev->status & 0x10)
609 if (copy_from_user(dev->bufptr, buf + hs, count - hs))
614 static ssize_t pg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
616 struct pg *dev = filp->private_data;
617 struct pg_read_hdr hdr;
618 int hs = sizeof (hdr);
628 if (pg_completion(dev, dev->bufptr, dev->timeout))
629 if (dev->status & 0x10)
632 hdr.magic = PG_MAGIC;
633 hdr.dlen = dev->dlen;
637 hdr.dlen = -1 * hdr.dlen;
639 if (copy > (count - hs))
643 hdr.duration = (jiffies - dev->start + HZ / 2) / HZ;
644 hdr.scsi = dev->status & 0x0f;
646 if (copy_to_user(buf, &hdr, hs))
649 if (copy_to_user(buf + hs, dev->bufptr, copy))
654 static int __init pg_init(void)
671 err = register_chrdev(major, name, &pg_fops);
673 printk("pg_init: unable to get major number %d\n", major);
674 for (unit = 0; unit < PG_UNITS; unit++) {
675 struct pg *dev = &devices[unit];
681 major = err; /* In case the user specified `major=0' (dynamic) */
682 pg_class = class_create(THIS_MODULE, "pg");
683 if (IS_ERR(pg_class)) {
684 err = PTR_ERR(pg_class);
687 for (unit = 0; unit < PG_UNITS; unit++) {
688 struct pg *dev = &devices[unit];
690 device_create(pg_class, NULL, MKDEV(major, unit), NULL,
697 unregister_chrdev(major, "pg");
702 static void __exit pg_exit(void)
706 for (unit = 0; unit < PG_UNITS; unit++) {
707 struct pg *dev = &devices[unit];
709 device_destroy(pg_class, MKDEV(major, unit));
711 class_destroy(pg_class);
712 unregister_chrdev(major, name);
714 for (unit = 0; unit < PG_UNITS; unit++) {
715 struct pg *dev = &devices[unit];
721 MODULE_LICENSE("GPL");