2 * atari_scsi.c -- Device dependent functions for the Atari generic SCSI port
4 * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
6 * Loosely based on the work of Robert De Vries' team and added:
8 * - Falcon support (untested yet!) ++bjoern fixed and now it works
9 * - lots of extensions and bug fixes.
11 * This file is subject to the terms and conditions of the GNU General Public
12 * License. See the file COPYING in the main directory of this archive
18 /**************************************************************************/
20 /* Notes for Falcon SCSI: */
21 /* ---------------------- */
23 /* Since the Falcon SCSI uses the ST-DMA chip, that is shared among */
24 /* several device drivers, locking and unlocking the access to this */
25 /* chip is required. But locking is not possible from an interrupt, */
26 /* since it puts the process to sleep if the lock is not available. */
27 /* This prevents "late" locking of the DMA chip, i.e. locking it just */
28 /* before using it, since in case of disconnection-reconnection */
29 /* commands, the DMA is started from the reselection interrupt. */
31 /* Two possible schemes for ST-DMA-locking would be: */
32 /* 1) The lock is taken for each command separately and disconnecting */
33 /* is forbidden (i.e. can_queue = 1). */
34 /* 2) The DMA chip is locked when the first command comes in and */
35 /* released when the last command is finished and all queues are */
37 /* The first alternative would result in bad performance, since the */
38 /* interleaving of commands would not be used. The second is unfair to */
39 /* other drivers using the ST-DMA, because the queues will seldom be */
40 /* totally empty if there is a lot of disk traffic. */
42 /* For this reasons I decided to employ a more elaborate scheme: */
43 /* - First, we give up the lock every time we can (for fairness), this */
44 /* means every time a command finishes and there are no other commands */
45 /* on the disconnected queue. */
46 /* - If there are others waiting to lock the DMA chip, we stop */
47 /* issuing commands, i.e. moving them onto the issue queue. */
48 /* Because of that, the disconnected queue will run empty in a */
49 /* while. Instead we go to sleep on a 'fairness_queue'. */
50 /* - If the lock is released, all processes waiting on the fairness */
51 /* queue will be woken. The first of them tries to re-lock the DMA, */
52 /* the others wait for the first to finish this task. After that, */
53 /* they can all run on and do their commands... */
54 /* This sounds complicated (and it is it :-(), but it seems to be a */
55 /* good compromise between fairness and performance: As long as no one */
56 /* else wants to work with the ST-DMA chip, SCSI can go along as */
57 /* usual. If now someone else comes, this behaviour is changed to a */
58 /* "fairness mode": just already initiated commands are finished and */
59 /* then the lock is released. The other one waiting will probably win */
60 /* the race for locking the DMA, since it was waiting for longer. And */
61 /* after it has finished, SCSI can go ahead again. Finally: I hope I */
62 /* have not produced any deadlock possibilities! */
64 /**************************************************************************/
67 #include <linux/module.h>
68 #include <linux/types.h>
69 #include <linux/blkdev.h>
70 #include <linux/interrupt.h>
71 #include <linux/init.h>
72 #include <linux/nvram.h>
73 #include <linux/bitops.h>
74 #include <linux/wait.h>
75 #include <linux/platform_device.h>
77 #include <asm/setup.h>
78 #include <asm/atarihw.h>
79 #include <asm/atariints.h>
80 #include <asm/atari_stdma.h>
81 #include <asm/atari_stram.h>
84 #include <scsi/scsi_host.h>
86 /* Definitions for the core NCR5380 driver. */
91 #define DMA_MIN_SIZE 32
93 #define NCR5380_implementation_fields /* none */
95 #define NCR5380_read(reg) atari_scsi_reg_read(reg)
96 #define NCR5380_write(reg, value) atari_scsi_reg_write(reg, value)
98 #define NCR5380_queue_command atari_scsi_queue_command
99 #define NCR5380_abort atari_scsi_abort
100 #define NCR5380_show_info atari_scsi_show_info
101 #define NCR5380_info atari_scsi_info
103 #define NCR5380_dma_read_setup(instance, data, count) \
104 atari_scsi_dma_setup(instance, data, count, 0)
105 #define NCR5380_dma_write_setup(instance, data, count) \
106 atari_scsi_dma_setup(instance, data, count, 1)
107 #define NCR5380_dma_residual(instance) \
108 atari_scsi_dma_residual(instance)
109 #define NCR5380_dma_xfer_len(instance, cmd, phase) \
110 atari_dma_xfer_len(cmd->SCp.this_residual, cmd, !((phase) & SR_IO))
112 #define NCR5380_acquire_dma_irq(instance) falcon_get_lock(instance)
113 #define NCR5380_release_dma_irq(instance) falcon_release_lock()
118 #define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)
120 #define SCSI_DMA_WRITE_P(elt,val) \
122 unsigned long v = val; \
123 tt_scsi_dma.elt##_lo = v & 0xff; \
125 tt_scsi_dma.elt##_lmd = v & 0xff; \
127 tt_scsi_dma.elt##_hmd = v & 0xff; \
129 tt_scsi_dma.elt##_hi = v & 0xff; \
132 #define SCSI_DMA_READ_P(elt) \
133 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \
134 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \
135 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \
136 (unsigned long)tt_scsi_dma.elt##_lo)
139 static inline void SCSI_DMA_SETADR(unsigned long adr
)
141 st_dma
.dma_lo
= (unsigned char)adr
;
144 st_dma
.dma_md
= (unsigned char)adr
;
147 st_dma
.dma_hi
= (unsigned char)adr
;
151 static inline unsigned long SCSI_DMA_GETADR(void)
156 adr
|= (st_dma
.dma_md
& 0xff) << 8;
158 adr
|= (st_dma
.dma_hi
& 0xff) << 16;
163 #define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \
164 (atari_scsi_host->hostdata))->dma_len)
167 static void atari_scsi_fetch_restbytes(void);
170 static struct Scsi_Host
*atari_scsi_host
;
171 static unsigned char (*atari_scsi_reg_read
)(unsigned char reg
);
172 static void (*atari_scsi_reg_write
)(unsigned char reg
, unsigned char value
);
175 static unsigned long atari_dma_residual
, atari_dma_startaddr
;
176 static short atari_dma_active
;
177 /* pointer to the dribble buffer */
178 static char *atari_dma_buffer
;
179 /* precalculated physical address of the dribble buffer */
180 static unsigned long atari_dma_phys_buffer
;
181 /* != 0 tells the Falcon int handler to copy data from the dribble buffer */
182 static char *atari_dma_orig_addr
;
183 /* size of the dribble buffer; 4k seems enough, since the Falcon cannot use
184 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare
185 * cases where requests to physical contiguous buffers have been merged, this
186 * request is <= 4k (one page). So I don't think we have to split transfers
187 * just due to this buffer size...
189 #define STRAM_BUFFER_SIZE (4096)
190 /* mask for address bits that can't be used with the ST-DMA */
191 static unsigned long atari_dma_stram_mask
;
192 #define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
195 static int setup_can_queue
= -1;
196 module_param(setup_can_queue
, int, 0);
197 static int setup_cmd_per_lun
= -1;
198 module_param(setup_cmd_per_lun
, int, 0);
199 static int setup_sg_tablesize
= -1;
200 module_param(setup_sg_tablesize
, int, 0);
201 static int setup_use_tagged_queuing
= -1;
202 module_param(setup_use_tagged_queuing
, int, 0);
203 static int setup_hostid
= -1;
204 module_param(setup_hostid
, int, 0);
205 static int setup_toshiba_delay
= -1;
206 module_param(setup_toshiba_delay
, int, 0);
209 #if defined(REAL_DMA)
211 static int scsi_dma_is_ignored_buserr(unsigned char dma_stat
)
214 unsigned long addr
= SCSI_DMA_READ_P(dma_addr
), end_addr
;
216 if (dma_stat
& 0x01) {
218 /* A bus error happens when DMA-ing from the last page of a
219 * physical memory chunk (DMA prefetch!), but that doesn't hurt.
220 * Check for this case:
223 for (i
= 0; i
< m68k_num_memory
; ++i
) {
224 end_addr
= m68k_memory
[i
].addr
+ m68k_memory
[i
].size
;
225 if (end_addr
<= addr
&& addr
<= end_addr
+ 4)
234 /* Dead code... wasn't called anyway :-) and causes some trouble, because at
235 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has
236 * to clear the DMA int pending bit before it allows other level 6 interrupts.
238 static void scsi_dma_buserr(int irq
, void *dummy
)
240 unsigned char dma_stat
= tt_scsi_dma
.dma_ctrl
;
242 /* Don't do anything if a NCR interrupt is pending. Probably it's just
244 if (atari_irq_pending(IRQ_TT_MFP_SCSI
))
247 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n",
248 SCSI_DMA_READ_P(dma_addr
), dma_stat
, SCSI_DMA_READ_P(dma_cnt
));
249 if (dma_stat
& 0x80) {
250 if (!scsi_dma_is_ignored_buserr(dma_stat
))
251 printk("SCSI DMA bus error -- bad DMA programming!\n");
253 /* Under normal circumstances we never should get to this point,
254 * since both interrupts are triggered simultaneously and the 5380
255 * int has higher priority. When this irq is handled, that DMA
256 * interrupt is cleared. So a warning message is printed here.
258 printk("SCSI DMA intr ?? -- this shouldn't happen!\n");
266 static irqreturn_t
scsi_tt_intr(int irq
, void *dummy
)
271 dma_stat
= tt_scsi_dma
.dma_ctrl
;
273 dprintk(NDEBUG_INTR
, "scsi%d: NCR5380 interrupt, DMA status = %02x\n",
274 atari_scsi_host
->host_no
, dma_stat
& 0xff);
276 /* Look if it was the DMA that has interrupted: First possibility
277 * is that a bus error occurred...
279 if (dma_stat
& 0x80) {
280 if (!scsi_dma_is_ignored_buserr(dma_stat
)) {
281 printk(KERN_ERR
"SCSI DMA caused bus error near 0x%08lx\n",
282 SCSI_DMA_READ_P(dma_addr
));
283 printk(KERN_CRIT
"SCSI DMA bus error -- bad DMA programming!");
287 /* If the DMA is active but not finished, we have the case
288 * that some other 5380 interrupt occurred within the DMA transfer.
289 * This means we have residual bytes, if the desired end address
290 * is not yet reached. Maybe we have to fetch some bytes from the
291 * rest data register, too. The residual must be calculated from
292 * the address pointer, not the counter register, because only the
293 * addr reg counts bytes not yet written and pending in the rest
296 if ((dma_stat
& 0x02) && !(dma_stat
& 0x40)) {
297 atari_dma_residual
= HOSTDATA_DMALEN
- (SCSI_DMA_READ_P(dma_addr
) - atari_dma_startaddr
);
299 dprintk(NDEBUG_DMA
, "SCSI DMA: There are %ld residual bytes.\n",
302 if ((signed int)atari_dma_residual
< 0)
303 atari_dma_residual
= 0;
304 if ((dma_stat
& 1) == 0) {
306 * After read operations, we maybe have to
307 * transport some rest bytes
309 atari_scsi_fetch_restbytes();
312 * There seems to be a nasty bug in some SCSI-DMA/NCR
313 * combinations: If a target disconnects while a write
314 * operation is going on, the address register of the
315 * DMA may be a few bytes farer than it actually read.
316 * This is probably due to DMA prefetching and a delay
317 * between DMA and NCR. Experiments showed that the
318 * dma_addr is 9 bytes to high, but this could vary.
319 * The problem is, that the residual is thus calculated
320 * wrong and the next transfer will start behind where
321 * it should. So we round up the residual to the next
322 * multiple of a sector size, if it isn't already a
323 * multiple and the originally expected transfer size
324 * was. The latter condition is there to ensure that
325 * the correction is taken only for "real" data
326 * transfers and not for, e.g., the parameters of some
327 * other command. These shouldn't disconnect anyway.
329 if (atari_dma_residual
& 0x1ff) {
330 dprintk(NDEBUG_DMA
, "SCSI DMA: DMA bug corrected, "
331 "difference %ld bytes\n",
332 512 - (atari_dma_residual
& 0x1ff));
333 atari_dma_residual
= (atari_dma_residual
+ 511) & ~0x1ff;
336 tt_scsi_dma
.dma_ctrl
= 0;
339 /* If the DMA is finished, fetch the rest bytes and turn it off */
340 if (dma_stat
& 0x40) {
341 atari_dma_residual
= 0;
342 if ((dma_stat
& 1) == 0)
343 atari_scsi_fetch_restbytes();
344 tt_scsi_dma
.dma_ctrl
= 0;
347 #endif /* REAL_DMA */
349 NCR5380_intr(irq
, dummy
);
355 static irqreturn_t
scsi_falcon_intr(int irq
, void *dummy
)
360 /* Turn off DMA and select sector counter register before
361 * accessing the status register (Atari recommendation!)
363 st_dma
.dma_mode_status
= 0x90;
364 dma_stat
= st_dma
.dma_mode_status
;
366 /* Bit 0 indicates some error in the DMA process... don't know
367 * what happened exactly (no further docu).
369 if (!(dma_stat
& 0x01)) {
371 printk(KERN_CRIT
"SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
374 /* If the DMA was active, but now bit 1 is not clear, it is some
375 * other 5380 interrupt that finishes the DMA transfer. We have to
376 * calculate the number of residual bytes and give a warning if
377 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
379 if (atari_dma_active
&& (dma_stat
& 0x02)) {
380 unsigned long transferred
;
382 transferred
= SCSI_DMA_GETADR() - atari_dma_startaddr
;
383 /* The ST-DMA address is incremented in 2-byte steps, but the
384 * data are written only in 16-byte chunks. If the number of
385 * transferred bytes is not divisible by 16, the remainder is
386 * lost somewhere in outer space.
388 if (transferred
& 15)
389 printk(KERN_ERR
"SCSI DMA error: %ld bytes lost in "
390 "ST-DMA fifo\n", transferred
& 15);
392 atari_dma_residual
= HOSTDATA_DMALEN
- transferred
;
393 dprintk(NDEBUG_DMA
, "SCSI DMA: There are %ld residual bytes.\n",
396 atari_dma_residual
= 0;
397 atari_dma_active
= 0;
399 if (atari_dma_orig_addr
) {
400 /* If the dribble buffer was used on a read operation, copy the DMA-ed
401 * data to the original destination address.
403 memcpy(atari_dma_orig_addr
, phys_to_virt(atari_dma_startaddr
),
404 HOSTDATA_DMALEN
- atari_dma_residual
);
405 atari_dma_orig_addr
= NULL
;
408 #endif /* REAL_DMA */
410 NCR5380_intr(irq
, dummy
);
416 static void atari_scsi_fetch_restbytes(void)
420 unsigned long phys_dst
;
422 /* fetch rest bytes in the DMA register */
423 phys_dst
= SCSI_DMA_READ_P(dma_addr
);
426 /* there are 'nr' bytes left for the last long address
427 before the DMA pointer */
429 dprintk(NDEBUG_DMA
, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
431 /* The content of the DMA pointer is a physical address! */
432 dst
= phys_to_virt(phys_dst
);
433 dprintk(NDEBUG_DMA
, " = virt addr %p\n", dst
);
434 for (src
= (char *)&tt_scsi_dma
.dma_restdata
; nr
!= 0; --nr
)
438 #endif /* REAL_DMA */
441 /* This function releases the lock on the DMA chip if there is no
442 * connected command and the disconnected queue is empty.
445 static void falcon_release_lock(void)
450 if (stdma_is_locked_by(scsi_falcon_intr
))
454 /* This function manages the locking of the ST-DMA.
455 * If the DMA isn't locked already for SCSI, it tries to lock it by
456 * calling stdma_lock(). But if the DMA is locked by the SCSI code and
457 * there are other drivers waiting for the chip, we do not issue the
458 * command immediately but tell the SCSI mid-layer to defer.
461 static int falcon_get_lock(struct Scsi_Host
*instance
)
467 return stdma_try_lock(scsi_falcon_intr
, instance
);
469 stdma_lock(scsi_falcon_intr
, instance
);
474 static int __init
atari_scsi_setup(char *str
)
476 /* Format of atascsi parameter is:
477 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
478 * Defaults depend on TT or Falcon, determined at run time.
479 * Negative values mean don't change.
483 get_options(str
, ARRAY_SIZE(ints
), ints
);
486 printk("atari_scsi_setup: no arguments!\n");
490 setup_can_queue
= ints
[1];
492 setup_cmd_per_lun
= ints
[2];
494 setup_sg_tablesize
= ints
[3];
496 setup_hostid
= ints
[4];
498 setup_use_tagged_queuing
= ints
[5];
499 /* ints[6] (use_pdma) is ignored */
501 setup_toshiba_delay
= ints
[7];
506 __setup("atascsi=", atari_scsi_setup
);
510 #if defined(REAL_DMA)
512 static unsigned long atari_scsi_dma_setup(struct Scsi_Host
*instance
,
513 void *data
, unsigned long count
,
516 unsigned long addr
= virt_to_phys(data
);
518 dprintk(NDEBUG_DMA
, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, "
519 "dir = %d\n", instance
->host_no
, data
, addr
, count
, dir
);
521 if (!IS_A_TT() && !STRAM_ADDR(addr
)) {
522 /* If we have a non-DMAable address on a Falcon, use the dribble
523 * buffer; 'orig_addr' != 0 in the read case tells the interrupt
524 * handler to copy data from the dribble buffer to the originally
528 memcpy(atari_dma_buffer
, data
, count
);
530 atari_dma_orig_addr
= data
;
531 addr
= atari_dma_phys_buffer
;
534 atari_dma_startaddr
= addr
; /* Needed for calculating residual later. */
536 /* Cache cleanup stuff: On writes, push any dirty cache out before sending
537 * it to the peripheral. (Must be done before DMA setup, since at least
538 * the ST-DMA begins to fill internal buffers right after setup. For
539 * reads, invalidate any cache, may be altered after DMA without CPU
542 * ++roman: For the Medusa, there's no need at all for that cache stuff,
543 * because the hardware does bus snooping (fine!).
545 dma_cache_maintenance(addr
, count
, dir
);
548 printk(KERN_NOTICE
"SCSI warning: DMA programmed for 0 bytes !\n");
551 tt_scsi_dma
.dma_ctrl
= dir
;
552 SCSI_DMA_WRITE_P(dma_addr
, addr
);
553 SCSI_DMA_WRITE_P(dma_cnt
, count
);
554 tt_scsi_dma
.dma_ctrl
= dir
| 2;
555 } else { /* ! IS_A_TT */
558 SCSI_DMA_SETADR(addr
);
560 /* toggle direction bit to clear FIFO and set DMA direction */
562 st_dma
.dma_mode_status
= 0x90 | dir
;
563 st_dma
.dma_mode_status
= 0x90 | (dir
^ 0x100);
564 st_dma
.dma_mode_status
= 0x90 | dir
;
566 /* On writes, round up the transfer length to the next multiple of 512
567 * (see also comment at atari_dma_xfer_len()). */
568 st_dma
.fdc_acces_seccount
= (count
+ (dir
? 511 : 0)) >> 9;
570 st_dma
.dma_mode_status
= 0x10 | dir
;
572 /* need not restore value of dir, only boolean value is tested */
573 atari_dma_active
= 1;
580 static long atari_scsi_dma_residual(struct Scsi_Host
*instance
)
582 return atari_dma_residual
;
586 #define CMD_SURELY_BLOCK_MODE 0
587 #define CMD_SURELY_BYTE_MODE 1
588 #define CMD_MODE_UNKNOWN 2
590 static int falcon_classify_cmd(struct scsi_cmnd
*cmd
)
592 unsigned char opcode
= cmd
->cmnd
[0];
594 if (opcode
== READ_DEFECT_DATA
|| opcode
== READ_LONG
||
595 opcode
== READ_BUFFER
)
596 return CMD_SURELY_BYTE_MODE
;
597 else if (opcode
== READ_6
|| opcode
== READ_10
||
598 opcode
== 0xa8 /* READ_12 */ || opcode
== READ_REVERSE
||
599 opcode
== RECOVER_BUFFERED_DATA
) {
600 /* In case of a sequential-access target (tape), special care is
601 * needed here: The transfer is block-mode only if the 'fixed' bit is
603 if (cmd
->device
->type
== TYPE_TAPE
&& !(cmd
->cmnd
[1] & 1))
604 return CMD_SURELY_BYTE_MODE
;
606 return CMD_SURELY_BLOCK_MODE
;
608 return CMD_MODE_UNKNOWN
;
612 /* This function calculates the number of bytes that can be transferred via
613 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
614 * ST-DMA chip. There are only multiples of 512 bytes possible and max.
615 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
616 * possible on the Falcon, since that would require to program the DMA for
617 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
618 * the overrun problem, so this question is academic :-)
621 static unsigned long atari_dma_xfer_len(unsigned long wanted_len
,
622 struct scsi_cmnd
*cmd
, int write_flag
)
624 unsigned long possible_len
, limit
;
627 /* TT SCSI DMA can transfer arbitrary #bytes */
630 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
631 * 255*512 bytes, but this should be enough)
633 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
634 * that return a number of bytes which cannot be known beforehand. In this
635 * case, the given transfer length is an "allocation length". Now it
636 * can happen that this allocation length is a multiple of 512 bytes and
637 * the DMA is used. But if not n*512 bytes really arrive, some input data
638 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
639 * between commands that do block transfers and those that do byte
640 * transfers. But this isn't easy... there are lots of vendor specific
641 * commands, and the user can issue any command via the
642 * SCSI_IOCTL_SEND_COMMAND.
644 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
645 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
646 * and 3), the thing to do is obvious: allow any number of blocks via DMA
647 * or none. In case 2), we apply some heuristic: Byte mode is assumed if
648 * the transfer (allocation) length is < 1024, hoping that no cmd. not
649 * explicitly known as byte mode have such big allocation lengths...
650 * BTW, all the discussion above applies only to reads. DMA writes are
651 * unproblematic anyways, since the targets aborts the transfer after
652 * receiving a sufficient number of bytes.
654 * Another point: If the transfer is from/to an non-ST-RAM address, we
655 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
659 /* Write operation can always use the DMA, but the transfer size must
660 * be rounded up to the next multiple of 512 (atari_dma_setup() does
663 possible_len
= wanted_len
;
665 /* Read operations: if the wanted transfer length is not a multiple of
666 * 512, we cannot use DMA, since the ST-DMA cannot split transfers
667 * (no interrupt on DMA finished!)
669 if (wanted_len
& 0x1ff)
672 /* Now classify the command (see above) and decide whether it is
673 * allowed to do DMA at all */
674 switch (falcon_classify_cmd(cmd
)) {
675 case CMD_SURELY_BLOCK_MODE
:
676 possible_len
= wanted_len
;
678 case CMD_SURELY_BYTE_MODE
:
679 possible_len
= 0; /* DMA prohibited */
681 case CMD_MODE_UNKNOWN
:
683 /* For unknown commands assume block transfers if the transfer
684 * size/allocation length is >= 1024 */
685 possible_len
= (wanted_len
< 1024) ? 0 : wanted_len
;
691 /* Last step: apply the hard limit on DMA transfers */
692 limit
= (atari_dma_buffer
&& !STRAM_ADDR(virt_to_phys(cmd
->SCp
.ptr
))) ?
693 STRAM_BUFFER_SIZE
: 255*512;
694 if (possible_len
> limit
)
695 possible_len
= limit
;
697 if (possible_len
!= wanted_len
)
698 dprintk(NDEBUG_DMA
, "Sorry, must cut DMA transfer size to %ld bytes "
699 "instead of %ld\n", possible_len
, wanted_len
);
705 #endif /* REAL_DMA */
708 /* NCR5380 register access functions
710 * There are separate functions for TT and Falcon, because the access
711 * methods are quite different. The calling macros NCR5380_read and
712 * NCR5380_write call these functions via function pointers.
715 static unsigned char atari_scsi_tt_reg_read(unsigned char reg
)
717 return tt_scsi_regp
[reg
* 2];
720 static void atari_scsi_tt_reg_write(unsigned char reg
, unsigned char value
)
722 tt_scsi_regp
[reg
* 2] = value
;
725 static unsigned char atari_scsi_falcon_reg_read(unsigned char reg
)
727 dma_wd
.dma_mode_status
= (u_short
)(0x88 + reg
);
728 return (u_char
)dma_wd
.fdc_acces_seccount
;
731 static void atari_scsi_falcon_reg_write(unsigned char reg
, unsigned char value
)
733 dma_wd
.dma_mode_status
= (u_short
)(0x88 + reg
);
734 dma_wd
.fdc_acces_seccount
= (u_short
)value
;
738 #include "atari_NCR5380.c"
740 static int atari_scsi_bus_reset(struct scsi_cmnd
*cmd
)
745 local_irq_save(flags
);
748 /* Abort a maybe active DMA transfer */
750 tt_scsi_dma
.dma_ctrl
= 0;
752 st_dma
.dma_mode_status
= 0x90;
753 atari_dma_active
= 0;
754 atari_dma_orig_addr
= NULL
;
758 rv
= NCR5380_bus_reset(cmd
);
760 /* The 5380 raises its IRQ line while _RST is active but the ST DMA
761 * "lock" has been released so this interrupt may end up handled by
762 * floppy or IDE driver (if one of them holds the lock). The NCR5380
763 * interrupt flag has been cleared already.
766 local_irq_restore(flags
);
771 #define DRV_MODULE_NAME "atari_scsi"
772 #define PFX DRV_MODULE_NAME ": "
774 static struct scsi_host_template atari_scsi_template
= {
775 .module
= THIS_MODULE
,
776 .proc_name
= DRV_MODULE_NAME
,
777 .show_info
= atari_scsi_show_info
,
778 .name
= "Atari native SCSI",
779 .info
= atari_scsi_info
,
780 .queuecommand
= atari_scsi_queue_command
,
781 .eh_abort_handler
= atari_scsi_abort
,
782 .eh_bus_reset_handler
= atari_scsi_bus_reset
,
784 .use_clustering
= DISABLE_CLUSTERING
787 static int __init
atari_scsi_probe(struct platform_device
*pdev
)
789 struct Scsi_Host
*instance
;
791 struct resource
*irq
;
794 irq
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
798 if (ATARIHW_PRESENT(TT_SCSI
)) {
799 atari_scsi_reg_read
= atari_scsi_tt_reg_read
;
800 atari_scsi_reg_write
= atari_scsi_tt_reg_write
;
802 atari_scsi_reg_read
= atari_scsi_falcon_reg_read
;
803 atari_scsi_reg_write
= atari_scsi_falcon_reg_write
;
806 /* The values for CMD_PER_LUN and CAN_QUEUE are somehow arbitrary.
807 * Higher values should work, too; try it!
808 * (But cmd_per_lun costs memory!)
810 * But there seems to be a bug somewhere that requires CAN_QUEUE to be
811 * 2*CMD_PER_LUN. At least on a TT, no spurious timeouts seen since
812 * changed CMD_PER_LUN...
814 * Note: The Falcon currently uses 8/1 setting due to unsolved problems
815 * with cmd_per_lun != 1
817 if (ATARIHW_PRESENT(TT_SCSI
)) {
818 atari_scsi_template
.can_queue
= 16;
819 atari_scsi_template
.cmd_per_lun
= 8;
820 atari_scsi_template
.sg_tablesize
= SG_ALL
;
822 atari_scsi_template
.can_queue
= 8;
823 atari_scsi_template
.cmd_per_lun
= 1;
824 atari_scsi_template
.sg_tablesize
= SG_NONE
;
827 if (setup_can_queue
> 0)
828 atari_scsi_template
.can_queue
= setup_can_queue
;
830 if (setup_cmd_per_lun
> 0)
831 atari_scsi_template
.cmd_per_lun
= setup_cmd_per_lun
;
833 /* Leave sg_tablesize at 0 on a Falcon! */
834 if (ATARIHW_PRESENT(TT_SCSI
) && setup_sg_tablesize
>= 0)
835 atari_scsi_template
.sg_tablesize
= setup_sg_tablesize
;
837 if (setup_hostid
>= 0) {
838 atari_scsi_template
.this_id
= setup_hostid
& 7;
840 /* Test if a host id is set in the NVRam */
841 if (ATARIHW_PRESENT(TT_CLK
) && nvram_check_checksum()) {
842 unsigned char b
= nvram_read_byte(16);
844 /* Arbitration enabled? (for TOS)
845 * If yes, use configured host ID
848 atari_scsi_template
.this_id
= b
& 7;
854 /* If running on a Falcon and if there's TT-Ram (i.e., more than one
855 * memory block, since there's always ST-Ram in a Falcon), then
856 * allocate a STRAM_BUFFER_SIZE byte dribble buffer for transfers
857 * from/to alternative Ram.
859 if (ATARIHW_PRESENT(ST_SCSI
) && !ATARIHW_PRESENT(EXTD_DMA
) &&
860 m68k_num_memory
> 1) {
861 atari_dma_buffer
= atari_stram_alloc(STRAM_BUFFER_SIZE
, "SCSI");
862 if (!atari_dma_buffer
) {
863 pr_err(PFX
"can't allocate ST-RAM double buffer\n");
866 atari_dma_phys_buffer
= atari_stram_to_phys(atari_dma_buffer
);
867 atari_dma_orig_addr
= 0;
871 instance
= scsi_host_alloc(&atari_scsi_template
,
872 sizeof(struct NCR5380_hostdata
));
877 atari_scsi_host
= instance
;
879 instance
->irq
= irq
->start
;
881 host_flags
|= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP
;
883 host_flags
|= setup_use_tagged_queuing
> 0 ? FLAG_TAGGED_QUEUING
: 0;
885 host_flags
|= setup_toshiba_delay
> 0 ? FLAG_TOSHIBA_DELAY
: 0;
887 error
= NCR5380_init(instance
, host_flags
);
892 error
= request_irq(instance
->irq
, scsi_tt_intr
, 0,
893 "NCR5380", instance
);
895 pr_err(PFX
"request irq %d failed, aborting\n",
899 tt_mfp
.active_edge
|= 0x80; /* SCSI int on L->H */
901 tt_scsi_dma
.dma_ctrl
= 0;
902 atari_dma_residual
= 0;
904 /* While the read overruns (described by Drew Eckhardt in
905 * NCR5380.c) never happened on TTs, they do in fact on the
906 * Medusa (This was the cause why SCSI didn't work right for
907 * so long there.) Since handling the overruns slows down
908 * a bit, I turned the #ifdef's into a runtime condition.
910 * In principle it should be sufficient to do max. 1 byte with
911 * PIO, but there is another problem on the Medusa with the DMA
912 * rest data register. So read_overruns is currently set
913 * to 4 to avoid having transfers that aren't a multiple of 4.
914 * If the rest data bug is fixed, this can be lowered to 1.
916 if (MACH_IS_MEDUSA
) {
917 struct NCR5380_hostdata
*hostdata
=
918 shost_priv(instance
);
920 hostdata
->read_overruns
= 4;
924 /* Nothing to do for the interrupt: the ST-DMA is initialized
928 atari_dma_residual
= 0;
929 atari_dma_active
= 0;
930 atari_dma_stram_mask
= (ATARIHW_PRESENT(EXTD_DMA
) ? 0x00000000
935 NCR5380_maybe_reset_bus(instance
);
937 error
= scsi_add_host(instance
, NULL
);
941 platform_set_drvdata(pdev
, instance
);
943 scsi_scan_host(instance
);
948 free_irq(instance
->irq
, instance
);
950 NCR5380_exit(instance
);
952 scsi_host_put(instance
);
954 if (atari_dma_buffer
)
955 atari_stram_free(atari_dma_buffer
);
959 static int __exit
atari_scsi_remove(struct platform_device
*pdev
)
961 struct Scsi_Host
*instance
= platform_get_drvdata(pdev
);
963 scsi_remove_host(instance
);
965 free_irq(instance
->irq
, instance
);
966 NCR5380_exit(instance
);
967 scsi_host_put(instance
);
968 if (atari_dma_buffer
)
969 atari_stram_free(atari_dma_buffer
);
973 static struct platform_driver atari_scsi_driver
= {
974 .remove
= __exit_p(atari_scsi_remove
),
976 .name
= DRV_MODULE_NAME
,
980 module_platform_driver_probe(atari_scsi_driver
, atari_scsi_probe
);
982 MODULE_ALIAS("platform:" DRV_MODULE_NAME
);
983 MODULE_LICENSE("GPL");