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