--- /dev/null
+/*
+ pg.c (c) 1998 Grant R. Guenther <grant@torque.net>
+ Under the terms of the GNU General Public License.
+
+ The pg driver provides a simple character device interface for
+ sending ATAPI commands to a device. With the exception of the
+ ATAPI reset operation, all operations are performed by a pair
+ of read and write operations to the appropriate /dev/pgN device.
+ A write operation delivers a command and any outbound data in
+ a single buffer. Normally, the write will succeed unless the
+ device is offline or malfunctioning, or there is already another
+ command pending. If the write succeeds, it should be followed
+ immediately by a read operation, to obtain any returned data and
+ status information. A read will fail if there is no operation
+ in progress.
+
+ As a special case, the device can be reset with a write operation,
+ and in this case, no following read is expected, or permitted.
+
+ There are no ioctl() operations. Any single operation
+ may transfer at most PG_MAX_DATA bytes. Note that the driver must
+ copy the data through an internal buffer. In keeping with all
+ current ATAPI devices, command packets are assumed to be exactly
+ 12 bytes in length.
+
+ To permit future changes to this interface, the headers in the
+ read and write buffers contain a single character "magic" flag.
+ Currently this flag must be the character "P".
+
+ By default, the driver will autoprobe for a single parallel
+ port ATAPI device, but if their individual parameters are
+ specified, the driver can handle up to 4 devices.
+
+ To use this device, you must have the following device
+ special files defined:
+
+ /dev/pg0 c 97 0
+ /dev/pg1 c 97 1
+ /dev/pg2 c 97 2
+ /dev/pg3 c 97 3
+
+ (You'll need to change the 97 to something else if you use
+ the 'major' parameter to install the driver on a different
+ major number.)
+
+ The behaviour of the pg driver can be altered by setting
+ some parameters from the insmod command line. The following
+ parameters are adjustable:
+
+ drive0 These four arguments can be arrays of
+ drive1 1-6 integers as follows:
+ drive2
+ drive3 <prt>,<pro>,<uni>,<mod>,<slv>,<dly>
+
+ Where,
+
+ <prt> is the base of the parallel port address for
+ the corresponding drive. (required)
+
+ <pro> is the protocol number for the adapter that
+ supports this drive. These numbers are
+ logged by 'paride' when the protocol modules
+ are initialised. (0 if not given)
+
+ <uni> for those adapters that support chained
+ devices, this is the unit selector for the
+ chain of devices on the given port. It should
+ be zero for devices that don't support chaining.
+ (0 if not given)
+
+ <mod> this can be -1 to choose the best mode, or one
+ of the mode numbers supported by the adapter.
+ (-1 if not given)
+
+ <slv> ATAPI devices can be jumpered to master or slave.
+ Set this to 0 to choose the master drive, 1 to
+ choose the slave, -1 (the default) to choose the
+ first drive found.
+
+ <dly> some parallel ports require the driver to
+ go more slowly. -1 sets a default value that
+ should work with the chosen protocol. Otherwise,
+ set this to a small integer, the larger it is
+ the slower the port i/o. In some cases, setting
+ this to zero will speed up the device. (default -1)
+
+ major You may use this parameter to overide the
+ default major number (97) that this driver
+ will use. Be sure to change the device
+ name as well.
+
+ name This parameter is a character string that
+ contains the name the kernel will use for this
+ device (in /proc output, for instance).
+ (default "pg").
+
+ verbose This parameter controls the amount of logging
+ that is done by the driver. Set it to 0 for
+ quiet operation, to 1 to enable progress
+ messages while the driver probes for devices,
+ or to 2 for full debug logging. (default 0)
+
+ If this driver is built into the kernel, you can use
+ the following command line parameters, with the same values
+ as the corresponding module parameters listed above:
+
+ pg.drive0
+ pg.drive1
+ pg.drive2
+ pg.drive3
+
+ In addition, you can use the parameter pg.disable to disable
+ the driver entirely.
+
+*/
+
+/* Changes:
+
+ 1.01 GRG 1998.06.16 Bug fixes
+ 1.02 GRG 1998.09.24 Added jumbo support
+
+*/
+
+#define PG_VERSION "1.02"
+#define PG_MAJOR 97
+#define PG_NAME "pg"
+#define PG_UNITS 4
+
+#ifndef PI_PG
+#define PI_PG 4
+#endif
+
+#include <linux/types.h>
+/* Here are things one can override from the insmod command.
+ Most are autoprobed by paride unless set here. Verbose is 0
+ by default.
+
+*/
+
+static int verbose;
+static int major = PG_MAJOR;
+static char *name = PG_NAME;
+static int disable = 0;
+
+static int drive0[6] = { 0, 0, 0, -1, -1, -1 };
+static int drive1[6] = { 0, 0, 0, -1, -1, -1 };
+static int drive2[6] = { 0, 0, 0, -1, -1, -1 };
+static int drive3[6] = { 0, 0, 0, -1, -1, -1 };
+
+static int (*drives[4])[6] = {&drive0, &drive1, &drive2, &drive3};
+static int pg_drive_count;
+
+enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_DLY};
+
+/* end of parameters */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/mtio.h>
+#include <linux/pg.h>
+#include <linux/device.h>
+#include <linux/sched.h> /* current, TASK_* */
+#include <linux/mutex.h>
+#include <linux/jiffies.h>
+
+#include <asm/uaccess.h>
+
+module_param(verbose, int, 0644);
+module_param(major, int, 0);
+module_param(name, charp, 0);
+module_param_array(drive0, int, NULL, 0);
+module_param_array(drive1, int, NULL, 0);
+module_param_array(drive2, int, NULL, 0);
+module_param_array(drive3, int, NULL, 0);
+
+#include "paride.h"
+
+#define PG_SPIN_DEL 50 /* spin delay in micro-seconds */
+#define PG_SPIN 200
+#define PG_TMO HZ
+#define PG_RESET_TMO 10*HZ
+
+#define STAT_ERR 0x01
+#define STAT_INDEX 0x02
+#define STAT_ECC 0x04
+#define STAT_DRQ 0x08
+#define STAT_SEEK 0x10
+#define STAT_WRERR 0x20
+#define STAT_READY 0x40
+#define STAT_BUSY 0x80
+
+#define ATAPI_IDENTIFY 0x12
+
+static DEFINE_MUTEX(pg_mutex);
+static int pg_open(struct inode *inode, struct file *file);
+static int pg_release(struct inode *inode, struct file *file);
+static ssize_t pg_read(struct file *filp, char __user *buf,
+ size_t count, loff_t * ppos);
+static ssize_t pg_write(struct file *filp, const char __user *buf,
+ size_t count, loff_t * ppos);
+static int pg_detect(void);
+
+#define PG_NAMELEN 8
+
+struct pg {
+ struct pi_adapter pia; /* interface to paride layer */
+ struct pi_adapter *pi;
+ int busy; /* write done, read expected */
+ int start; /* jiffies at command start */
+ int dlen; /* transfer size requested */
+ unsigned long timeout; /* timeout requested */
+ int status; /* last sense key */
+ int drive; /* drive */
+ unsigned long access; /* count of active opens ... */
+ int present; /* device present ? */
+ char *bufptr;
+ char name[PG_NAMELEN]; /* pg0, pg1, ... */
+};
+
+static struct pg devices[PG_UNITS];
+
+static int pg_identify(struct pg *dev, int log);
+
+static char pg_scratch[512]; /* scratch block buffer */
+
+static struct class *pg_class;
+
+/* kernel glue structures */
+
+static const struct file_operations pg_fops = {
+ .owner = THIS_MODULE,
+ .read = pg_read,
+ .write = pg_write,
+ .open = pg_open,
+ .release = pg_release,
+ .llseek = noop_llseek,
+};
+
+static void pg_init_units(void)
+{
+ int unit;
+
+ pg_drive_count = 0;
+ for (unit = 0; unit < PG_UNITS; unit++) {
+ int *parm = *drives[unit];
+ struct pg *dev = &devices[unit];
+ dev->pi = &dev->pia;
+ clear_bit(0, &dev->access);
+ dev->busy = 0;
+ dev->present = 0;
+ dev->bufptr = NULL;
+ dev->drive = parm[D_SLV];
+ snprintf(dev->name, PG_NAMELEN, "%s%c", name, 'a'+unit);
+ if (parm[D_PRT])
+ pg_drive_count++;
+ }
+}
+
+static inline int status_reg(struct pg *dev)
+{
+ return pi_read_regr(dev->pi, 1, 6);
+}
+
+static inline int read_reg(struct pg *dev, int reg)
+{
+ return pi_read_regr(dev->pi, 0, reg);
+}
+
+static inline void write_reg(struct pg *dev, int reg, int val)
+{
+ pi_write_regr(dev->pi, 0, reg, val);
+}
+
+static inline u8 DRIVE(struct pg *dev)
+{
+ return 0xa0+0x10*dev->drive;
+}
+
+static void pg_sleep(int cs)
+{
+ schedule_timeout_interruptible(cs);
+}
+
+static int pg_wait(struct pg *dev, int go, int stop, unsigned long tmo, char *msg)
+{
+ int j, r, e, s, p, to;
+
+ dev->status = 0;
+
+ j = 0;
+ while ((((r = status_reg(dev)) & go) || (stop && (!(r & stop))))
+ && time_before(jiffies, tmo)) {
+ if (j++ < PG_SPIN)
+ udelay(PG_SPIN_DEL);
+ else
+ pg_sleep(1);
+ }
+
+ to = time_after_eq(jiffies, tmo);
+
+ if ((r & (STAT_ERR & stop)) || to) {
+ s = read_reg(dev, 7);
+ e = read_reg(dev, 1);
+ p = read_reg(dev, 2);
+ if (verbose > 1)
+ printk("%s: %s: stat=0x%x err=0x%x phase=%d%s\n",
+ dev->name, msg, s, e, p, to ? " timeout" : "");
+ if (to)
+ e |= 0x100;
+ dev->status = (e >> 4) & 0xff;
+ return -1;
+ }
+ return 0;
+}
+
+static int pg_command(struct pg *dev, char *cmd, int dlen, unsigned long tmo)
+{
+ int k;
+
+ pi_connect(dev->pi);
+
+ write_reg(dev, 6, DRIVE(dev));
+
+ if (pg_wait(dev, STAT_BUSY | STAT_DRQ, 0, tmo, "before command"))
+ goto fail;
+
+ write_reg(dev, 4, dlen % 256);
+ write_reg(dev, 5, dlen / 256);
+ write_reg(dev, 7, 0xa0); /* ATAPI packet command */
+
+ if (pg_wait(dev, STAT_BUSY, STAT_DRQ, tmo, "command DRQ"))
+ goto fail;
+
+ if (read_reg(dev, 2) != 1) {
+ printk("%s: command phase error\n", dev->name);
+ goto fail;
+ }
+
+ pi_write_block(dev->pi, cmd, 12);
+
+ if (verbose > 1) {
+ printk("%s: Command sent, dlen=%d packet= ", dev->name, dlen);
+ for (k = 0; k < 12; k++)
+ printk("%02x ", cmd[k] & 0xff);
+ printk("\n");
+ }
+ return 0;
+fail:
+ pi_disconnect(dev->pi);
+ return -1;
+}
+
+static int pg_completion(struct pg *dev, char *buf, unsigned long tmo)
+{
+ int r, d, n, p;
+
+ r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
+ tmo, "completion");
+
+ dev->dlen = 0;
+
+ while (read_reg(dev, 7) & STAT_DRQ) {
+ d = (read_reg(dev, 4) + 256 * read_reg(dev, 5));
+ n = ((d + 3) & 0xfffc);
+ p = read_reg(dev, 2) & 3;
+ if (p == 0)
+ pi_write_block(dev->pi, buf, n);
+ if (p == 2)
+ pi_read_block(dev->pi, buf, n);
+ if (verbose > 1)
+ printk("%s: %s %d bytes\n", dev->name,
+ p ? "Read" : "Write", n);
+ dev->dlen += (1 - p) * d;
+ buf += d;
+ r = pg_wait(dev, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
+ tmo, "completion");
+ }
+
+ pi_disconnect(dev->pi);
+
+ return r;
+}
+
+static int pg_reset(struct pg *dev)
+{
+ int i, k, err;
+ int expect[5] = { 1, 1, 1, 0x14, 0xeb };
+ int got[5];
+
+ pi_connect(dev->pi);
+ write_reg(dev, 6, DRIVE(dev));
+ write_reg(dev, 7, 8);
+
+ pg_sleep(20 * HZ / 1000);
+
+ k = 0;
+ while ((k++ < PG_RESET_TMO) && (status_reg(dev) & STAT_BUSY))
+ pg_sleep(1);
+
+ for (i = 0; i < 5; i++)
+ got[i] = read_reg(dev, i + 1);
+
+ err = memcmp(expect, got, sizeof(got)) ? -1 : 0;
+
+ if (verbose) {
+ printk("%s: Reset (%d) signature = ", dev->name, k);
+ for (i = 0; i < 5; i++)
+ printk("%3x", got[i]);
+ if (err)
+ printk(" (incorrect)");
+ printk("\n");
+ }
+
+ pi_disconnect(dev->pi);
+ return err;
+}
+
+static void xs(char *buf, char *targ, int len)
+{
+ char l = '\0';
+ int k;
+
+ for (k = 0; k < len; k++) {
+ char c = *buf++;
+ if (c != ' ' && c != l)
+ l = *targ++ = c;
+ }
+ if (l == ' ')
+ targ--;
+ *targ = '\0';
+}
+
+static int pg_identify(struct pg *dev, int log)
+{
+ int s;
+ char *ms[2] = { "master", "slave" };
+ char mf[10], id[18];
+ char id_cmd[12] = { ATAPI_IDENTIFY, 0, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0 };
+ char buf[36];
+
+ s = pg_command(dev, id_cmd, 36, jiffies + PG_TMO);
+ if (s)
+ return -1;
+ s = pg_completion(dev, buf, jiffies + PG_TMO);
+ if (s)
+ return -1;
+
+ if (log) {
+ xs(buf + 8, mf, 8);
+ xs(buf + 16, id, 16);
+ printk("%s: %s %s, %s\n", dev->name, mf, id, ms[dev->drive]);
+ }
+
+ return 0;
+}
+
+/*
+ * returns 0, with id set if drive is detected
+ * -1, if drive detection failed
+ */
+static int pg_probe(struct pg *dev)
+{
+ if (dev->drive == -1) {
+ for (dev->drive = 0; dev->drive <= 1; dev->drive++)
+ if (!pg_reset(dev))
+ return pg_identify(dev, 1);
+ } else {
+ if (!pg_reset(dev))
+ return pg_identify(dev, 1);
+ }
+ return -1;
+}
+
+static int pg_detect(void)
+{
+ struct pg *dev = &devices[0];
+ int k, unit;
+
+ printk("%s: %s version %s, major %d\n", name, name, PG_VERSION, major);
+
+ k = 0;
+ if (pg_drive_count == 0) {
+ if (pi_init(dev->pi, 1, -1, -1, -1, -1, -1, pg_scratch,
+ PI_PG, verbose, dev->name)) {
+ if (!pg_probe(dev)) {
+ dev->present = 1;
+ k++;
+ } else
+ pi_release(dev->pi);
+ }
+
+ } else
+ for (unit = 0; unit < PG_UNITS; unit++, dev++) {
+ int *parm = *drives[unit];
+ if (!parm[D_PRT])
+ continue;
+ if (pi_init(dev->pi, 0, parm[D_PRT], parm[D_MOD],
+ parm[D_UNI], parm[D_PRO], parm[D_DLY],
+ pg_scratch, PI_PG, verbose, dev->name)) {
+ if (!pg_probe(dev)) {
+ dev->present = 1;
+ k++;
+ } else
+ pi_release(dev->pi);
+ }
+ }
+
+ if (k)
+ return 0;
+
+ printk("%s: No ATAPI device detected\n", name);
+ return -1;
+}
+
+static int pg_open(struct inode *inode, struct file *file)
+{
+ int unit = iminor(inode) & 0x7f;
+ struct pg *dev = &devices[unit];
+ int ret = 0;
+
+ mutex_lock(&pg_mutex);
+ if ((unit >= PG_UNITS) || (!dev->present)) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (test_and_set_bit(0, &dev->access)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ if (dev->busy) {
+ pg_reset(dev);
+ dev->busy = 0;
+ }
+
+ pg_identify(dev, (verbose > 1));
+
+ dev->bufptr = kmalloc(PG_MAX_DATA, GFP_KERNEL);
+ if (dev->bufptr == NULL) {
+ clear_bit(0, &dev->access);
+ printk("%s: buffer allocation failed\n", dev->name);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ file->private_data = dev;
+
+out:
+ mutex_unlock(&pg_mutex);
+ return ret;
+}
+
+static int pg_release(struct inode *inode, struct file *file)
+{
+ struct pg *dev = file->private_data;
+
+ kfree(dev->bufptr);
+ dev->bufptr = NULL;
+ clear_bit(0, &dev->access);
+
+ return 0;
+}
+
+static ssize_t pg_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos)
+{
+ struct pg *dev = filp->private_data;
+ struct pg_write_hdr hdr;
+ int hs = sizeof (hdr);
+
+ if (dev->busy)
+ return -EBUSY;
+ if (count < hs)
+ return -EINVAL;
+
+ if (copy_from_user(&hdr, buf, hs))
+ return -EFAULT;
+
+ if (hdr.magic != PG_MAGIC)
+ return -EINVAL;
+ if (hdr.dlen < 0 || hdr.dlen > PG_MAX_DATA)
+ return -EINVAL;
+ if ((count - hs) > PG_MAX_DATA)
+ return -EINVAL;
+
+ if (hdr.func == PG_RESET) {
+ if (count != hs)
+ return -EINVAL;
+ if (pg_reset(dev))
+ return -EIO;
+ return count;
+ }
+
+ if (hdr.func != PG_COMMAND)
+ return -EINVAL;
+
+ dev->start = jiffies;
+ dev->timeout = hdr.timeout * HZ + HZ / 2 + jiffies;
+
+ if (pg_command(dev, hdr.packet, hdr.dlen, jiffies + PG_TMO)) {
+ if (dev->status & 0x10)
+ return -ETIME;
+ return -EIO;
+ }
+
+ dev->busy = 1;
+
+ if (copy_from_user(dev->bufptr, buf + hs, count - hs))
+ return -EFAULT;
+ return count;
+}
+
+static ssize_t pg_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
+{
+ struct pg *dev = filp->private_data;
+ struct pg_read_hdr hdr;
+ int hs = sizeof (hdr);
+ int copy;
+
+ if (!dev->busy)
+ return -EINVAL;
+ if (count < hs)
+ return -EINVAL;
+
+ dev->busy = 0;
+
+ if (pg_completion(dev, dev->bufptr, dev->timeout))
+ if (dev->status & 0x10)
+ return -ETIME;
+
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.magic = PG_MAGIC;
+ hdr.dlen = dev->dlen;
+ copy = 0;
+
+ if (hdr.dlen < 0) {
+ hdr.dlen = -1 * hdr.dlen;
+ copy = hdr.dlen;
+ if (copy > (count - hs))
+ copy = count - hs;
+ }
+
+ hdr.duration = (jiffies - dev->start + HZ / 2) / HZ;
+ hdr.scsi = dev->status & 0x0f;
+
+ if (copy_to_user(buf, &hdr, hs))
+ return -EFAULT;
+ if (copy > 0)
+ if (copy_to_user(buf + hs, dev->bufptr, copy))
+ return -EFAULT;
+ return copy + hs;
+}
+
+static int __init pg_init(void)
+{
+ int unit;
+ int err;
+
+ if (disable){
+ err = -EINVAL;
+ goto out;
+ }
+
+ pg_init_units();
+
+ if (pg_detect()) {
+ err = -ENODEV;
+ goto out;
+ }
+
+ err = register_chrdev(major, name, &pg_fops);
+ if (err < 0) {
+ printk("pg_init: unable to get major number %d\n", major);
+ for (unit = 0; unit < PG_UNITS; unit++) {
+ struct pg *dev = &devices[unit];
+ if (dev->present)
+ pi_release(dev->pi);
+ }
+ goto out;
+ }
+ major = err; /* In case the user specified `major=0' (dynamic) */
+ pg_class = class_create(THIS_MODULE, "pg");
+ if (IS_ERR(pg_class)) {
+ err = PTR_ERR(pg_class);
+ goto out_chrdev;
+ }
+ for (unit = 0; unit < PG_UNITS; unit++) {
+ struct pg *dev = &devices[unit];
+ if (dev->present)
+ device_create(pg_class, NULL, MKDEV(major, unit), NULL,
+ "pg%u", unit);
+ }
+ err = 0;
+ goto out;
+
+out_chrdev:
+ unregister_chrdev(major, "pg");
+out:
+ return err;
+}
+
+static void __exit pg_exit(void)
+{
+ int unit;
+
+ for (unit = 0; unit < PG_UNITS; unit++) {
+ struct pg *dev = &devices[unit];
+ if (dev->present)
+ device_destroy(pg_class, MKDEV(major, unit));
+ }
+ class_destroy(pg_class);
+ unregister_chrdev(major, name);
+
+ for (unit = 0; unit < PG_UNITS; unit++) {
+ struct pg *dev = &devices[unit];
+ if (dev->present)
+ pi_release(dev->pi);
+ }
+}
+
+MODULE_LICENSE("GPL");
+module_init(pg_init)
+module_exit(pg_exit)
Code Review / kvmfornfv.git / blobdiff