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 * Notes for Falcon SCSI DMA
20 * The 5380 device is one of several that all share the DMA chip. Hence
21 * "locking" and "unlocking" access to this chip is required.
23 * Two possible schemes for ST DMA acquisition by atari_scsi are:
24 * 1) The lock is taken for each command separately (i.e. can_queue == 1).
25 * 2) The lock is taken when the first command arrives and released
26 * when the last command is finished (i.e. can_queue > 1).
28 * The first alternative limits SCSI bus utilization, since interleaving
29 * commands is not possible. The second gives better performance but is
30 * unfair to other drivers needing to use the ST DMA chip. In order to
31 * allow the IDE and floppy drivers equal access to the ST DMA chip
32 * the default is can_queue == 1.
35 #include <linux/module.h>
36 #include <linux/types.h>
37 #include <linux/blkdev.h>
38 #include <linux/interrupt.h>
39 #include <linux/init.h>
40 #include <linux/nvram.h>
41 #include <linux/bitops.h>
42 #include <linux/wait.h>
43 #include <linux/platform_device.h>
45 #include <asm/setup.h>
46 #include <asm/atarihw.h>
47 #include <asm/atariints.h>
48 #include <asm/atari_stdma.h>
49 #include <asm/atari_stram.h>
52 #include <scsi/scsi_host.h>
54 #define DMA_MIN_SIZE 32
56 /* Definitions for the core NCR5380 driver. */
58 #define NCR5380_implementation_fields /* none */
60 static u8 (*atari_scsi_reg_read
)(unsigned int);
61 static void (*atari_scsi_reg_write
)(unsigned int, u8
);
63 #define NCR5380_read(reg) atari_scsi_reg_read(reg)
64 #define NCR5380_write(reg, value) atari_scsi_reg_write(reg, value)
66 #define NCR5380_queue_command atari_scsi_queue_command
67 #define NCR5380_abort atari_scsi_abort
68 #define NCR5380_info atari_scsi_info
70 #define NCR5380_dma_xfer_len atari_scsi_dma_xfer_len
71 #define NCR5380_dma_recv_setup atari_scsi_dma_recv_setup
72 #define NCR5380_dma_send_setup atari_scsi_dma_send_setup
73 #define NCR5380_dma_residual atari_scsi_dma_residual
75 #define NCR5380_acquire_dma_irq(instance) falcon_get_lock(instance)
76 #define NCR5380_release_dma_irq(instance) falcon_release_lock()
81 #define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)
83 #define SCSI_DMA_WRITE_P(elt,val) \
85 unsigned long v = val; \
86 tt_scsi_dma.elt##_lo = v & 0xff; \
88 tt_scsi_dma.elt##_lmd = v & 0xff; \
90 tt_scsi_dma.elt##_hmd = v & 0xff; \
92 tt_scsi_dma.elt##_hi = v & 0xff; \
95 #define SCSI_DMA_READ_P(elt) \
96 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \
97 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \
98 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \
99 (unsigned long)tt_scsi_dma.elt##_lo)
102 static inline void SCSI_DMA_SETADR(unsigned long adr
)
104 st_dma
.dma_lo
= (unsigned char)adr
;
107 st_dma
.dma_md
= (unsigned char)adr
;
110 st_dma
.dma_hi
= (unsigned char)adr
;
114 static inline unsigned long SCSI_DMA_GETADR(void)
119 adr
|= (st_dma
.dma_md
& 0xff) << 8;
121 adr
|= (st_dma
.dma_hi
& 0xff) << 16;
126 static void atari_scsi_fetch_restbytes(void);
128 static unsigned long atari_dma_residual
, atari_dma_startaddr
;
129 static short atari_dma_active
;
130 /* pointer to the dribble buffer */
131 static char *atari_dma_buffer
;
132 /* precalculated physical address of the dribble buffer */
133 static unsigned long atari_dma_phys_buffer
;
134 /* != 0 tells the Falcon int handler to copy data from the dribble buffer */
135 static char *atari_dma_orig_addr
;
136 /* size of the dribble buffer; 4k seems enough, since the Falcon cannot use
137 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare
138 * cases where requests to physical contiguous buffers have been merged, this
139 * request is <= 4k (one page). So I don't think we have to split transfers
140 * just due to this buffer size...
142 #define STRAM_BUFFER_SIZE (4096)
143 /* mask for address bits that can't be used with the ST-DMA */
144 static unsigned long atari_dma_stram_mask
;
145 #define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
147 static int setup_can_queue
= -1;
148 module_param(setup_can_queue
, int, 0);
149 static int setup_cmd_per_lun
= -1;
150 module_param(setup_cmd_per_lun
, int, 0);
151 static int setup_sg_tablesize
= -1;
152 module_param(setup_sg_tablesize
, int, 0);
153 static int setup_hostid
= -1;
154 module_param(setup_hostid
, int, 0);
155 static int setup_toshiba_delay
= -1;
156 module_param(setup_toshiba_delay
, int, 0);
159 static int scsi_dma_is_ignored_buserr(unsigned char dma_stat
)
162 unsigned long addr
= SCSI_DMA_READ_P(dma_addr
), end_addr
;
164 if (dma_stat
& 0x01) {
166 /* A bus error happens when DMA-ing from the last page of a
167 * physical memory chunk (DMA prefetch!), but that doesn't hurt.
168 * Check for this case:
171 for (i
= 0; i
< m68k_num_memory
; ++i
) {
172 end_addr
= m68k_memory
[i
].addr
+ m68k_memory
[i
].size
;
173 if (end_addr
<= addr
&& addr
<= end_addr
+ 4)
182 /* Dead code... wasn't called anyway :-) and causes some trouble, because at
183 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has
184 * to clear the DMA int pending bit before it allows other level 6 interrupts.
186 static void scsi_dma_buserr(int irq
, void *dummy
)
188 unsigned char dma_stat
= tt_scsi_dma
.dma_ctrl
;
190 /* Don't do anything if a NCR interrupt is pending. Probably it's just
192 if (atari_irq_pending(IRQ_TT_MFP_SCSI
))
195 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n",
196 SCSI_DMA_READ_P(dma_addr
), dma_stat
, SCSI_DMA_READ_P(dma_cnt
));
197 if (dma_stat
& 0x80) {
198 if (!scsi_dma_is_ignored_buserr(dma_stat
))
199 printk("SCSI DMA bus error -- bad DMA programming!\n");
201 /* Under normal circumstances we never should get to this point,
202 * since both interrupts are triggered simultaneously and the 5380
203 * int has higher priority. When this irq is handled, that DMA
204 * interrupt is cleared. So a warning message is printed here.
206 printk("SCSI DMA intr ?? -- this shouldn't happen!\n");
212 static irqreturn_t
scsi_tt_intr(int irq
, void *dev
)
214 struct Scsi_Host
*instance
= dev
;
215 struct NCR5380_hostdata
*hostdata
= shost_priv(instance
);
218 dma_stat
= tt_scsi_dma
.dma_ctrl
;
220 dsprintk(NDEBUG_INTR
, instance
, "NCR5380 interrupt, DMA status = %02x\n",
223 /* Look if it was the DMA that has interrupted: First possibility
224 * is that a bus error occurred...
226 if (dma_stat
& 0x80) {
227 if (!scsi_dma_is_ignored_buserr(dma_stat
)) {
228 printk(KERN_ERR
"SCSI DMA caused bus error near 0x%08lx\n",
229 SCSI_DMA_READ_P(dma_addr
));
230 printk(KERN_CRIT
"SCSI DMA bus error -- bad DMA programming!");
234 /* If the DMA is active but not finished, we have the case
235 * that some other 5380 interrupt occurred within the DMA transfer.
236 * This means we have residual bytes, if the desired end address
237 * is not yet reached. Maybe we have to fetch some bytes from the
238 * rest data register, too. The residual must be calculated from
239 * the address pointer, not the counter register, because only the
240 * addr reg counts bytes not yet written and pending in the rest
243 if ((dma_stat
& 0x02) && !(dma_stat
& 0x40)) {
244 atari_dma_residual
= hostdata
->dma_len
-
245 (SCSI_DMA_READ_P(dma_addr
) - atari_dma_startaddr
);
247 dprintk(NDEBUG_DMA
, "SCSI DMA: There are %ld residual bytes.\n",
250 if ((signed int)atari_dma_residual
< 0)
251 atari_dma_residual
= 0;
252 if ((dma_stat
& 1) == 0) {
254 * After read operations, we maybe have to
255 * transport some rest bytes
257 atari_scsi_fetch_restbytes();
260 * There seems to be a nasty bug in some SCSI-DMA/NCR
261 * combinations: If a target disconnects while a write
262 * operation is going on, the address register of the
263 * DMA may be a few bytes farer than it actually read.
264 * This is probably due to DMA prefetching and a delay
265 * between DMA and NCR. Experiments showed that the
266 * dma_addr is 9 bytes to high, but this could vary.
267 * The problem is, that the residual is thus calculated
268 * wrong and the next transfer will start behind where
269 * it should. So we round up the residual to the next
270 * multiple of a sector size, if it isn't already a
271 * multiple and the originally expected transfer size
272 * was. The latter condition is there to ensure that
273 * the correction is taken only for "real" data
274 * transfers and not for, e.g., the parameters of some
275 * other command. These shouldn't disconnect anyway.
277 if (atari_dma_residual
& 0x1ff) {
278 dprintk(NDEBUG_DMA
, "SCSI DMA: DMA bug corrected, "
279 "difference %ld bytes\n",
280 512 - (atari_dma_residual
& 0x1ff));
281 atari_dma_residual
= (atari_dma_residual
+ 511) & ~0x1ff;
284 tt_scsi_dma
.dma_ctrl
= 0;
287 /* If the DMA is finished, fetch the rest bytes and turn it off */
288 if (dma_stat
& 0x40) {
289 atari_dma_residual
= 0;
290 if ((dma_stat
& 1) == 0)
291 atari_scsi_fetch_restbytes();
292 tt_scsi_dma
.dma_ctrl
= 0;
295 NCR5380_intr(irq
, dev
);
301 static irqreturn_t
scsi_falcon_intr(int irq
, void *dev
)
303 struct Scsi_Host
*instance
= dev
;
304 struct NCR5380_hostdata
*hostdata
= shost_priv(instance
);
307 /* Turn off DMA and select sector counter register before
308 * accessing the status register (Atari recommendation!)
310 st_dma
.dma_mode_status
= 0x90;
311 dma_stat
= st_dma
.dma_mode_status
;
313 /* Bit 0 indicates some error in the DMA process... don't know
314 * what happened exactly (no further docu).
316 if (!(dma_stat
& 0x01)) {
318 printk(KERN_CRIT
"SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
321 /* If the DMA was active, but now bit 1 is not clear, it is some
322 * other 5380 interrupt that finishes the DMA transfer. We have to
323 * calculate the number of residual bytes and give a warning if
324 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
326 if (atari_dma_active
&& (dma_stat
& 0x02)) {
327 unsigned long transferred
;
329 transferred
= SCSI_DMA_GETADR() - atari_dma_startaddr
;
330 /* The ST-DMA address is incremented in 2-byte steps, but the
331 * data are written only in 16-byte chunks. If the number of
332 * transferred bytes is not divisible by 16, the remainder is
333 * lost somewhere in outer space.
335 if (transferred
& 15)
336 printk(KERN_ERR
"SCSI DMA error: %ld bytes lost in "
337 "ST-DMA fifo\n", transferred
& 15);
339 atari_dma_residual
= hostdata
->dma_len
- transferred
;
340 dprintk(NDEBUG_DMA
, "SCSI DMA: There are %ld residual bytes.\n",
343 atari_dma_residual
= 0;
344 atari_dma_active
= 0;
346 if (atari_dma_orig_addr
) {
347 /* If the dribble buffer was used on a read operation, copy the DMA-ed
348 * data to the original destination address.
350 memcpy(atari_dma_orig_addr
, phys_to_virt(atari_dma_startaddr
),
351 hostdata
->dma_len
- atari_dma_residual
);
352 atari_dma_orig_addr
= NULL
;
355 NCR5380_intr(irq
, dev
);
361 static void atari_scsi_fetch_restbytes(void)
365 unsigned long phys_dst
;
367 /* fetch rest bytes in the DMA register */
368 phys_dst
= SCSI_DMA_READ_P(dma_addr
);
371 /* there are 'nr' bytes left for the last long address
372 before the DMA pointer */
374 dprintk(NDEBUG_DMA
, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
376 /* The content of the DMA pointer is a physical address! */
377 dst
= phys_to_virt(phys_dst
);
378 dprintk(NDEBUG_DMA
, " = virt addr %p\n", dst
);
379 for (src
= (char *)&tt_scsi_dma
.dma_restdata
; nr
!= 0; --nr
)
385 /* This function releases the lock on the DMA chip if there is no
386 * connected command and the disconnected queue is empty.
389 static void falcon_release_lock(void)
394 if (stdma_is_locked_by(scsi_falcon_intr
))
398 /* This function manages the locking of the ST-DMA.
399 * If the DMA isn't locked already for SCSI, it tries to lock it by
400 * calling stdma_lock(). But if the DMA is locked by the SCSI code and
401 * there are other drivers waiting for the chip, we do not issue the
402 * command immediately but tell the SCSI mid-layer to defer.
405 static int falcon_get_lock(struct Scsi_Host
*instance
)
410 if (stdma_is_locked_by(scsi_falcon_intr
) &&
411 instance
->hostt
->can_queue
> 1)
415 return stdma_try_lock(scsi_falcon_intr
, instance
);
417 stdma_lock(scsi_falcon_intr
, instance
);
422 static int __init
atari_scsi_setup(char *str
)
424 /* Format of atascsi parameter is:
425 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
426 * Defaults depend on TT or Falcon, determined at run time.
427 * Negative values mean don't change.
431 get_options(str
, ARRAY_SIZE(ints
), ints
);
434 printk("atari_scsi_setup: no arguments!\n");
438 setup_can_queue
= ints
[1];
440 setup_cmd_per_lun
= ints
[2];
442 setup_sg_tablesize
= ints
[3];
444 setup_hostid
= ints
[4];
445 /* ints[5] (use_tagged_queuing) is ignored */
446 /* ints[6] (use_pdma) is ignored */
448 setup_toshiba_delay
= ints
[7];
453 __setup("atascsi=", atari_scsi_setup
);
456 static unsigned long atari_scsi_dma_setup(struct NCR5380_hostdata
*hostdata
,
457 void *data
, unsigned long count
,
460 unsigned long addr
= virt_to_phys(data
);
462 dprintk(NDEBUG_DMA
, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, dir = %d\n",
463 hostdata
->host
->host_no
, data
, addr
, count
, dir
);
465 if (!IS_A_TT() && !STRAM_ADDR(addr
)) {
466 /* If we have a non-DMAable address on a Falcon, use the dribble
467 * buffer; 'orig_addr' != 0 in the read case tells the interrupt
468 * handler to copy data from the dribble buffer to the originally
472 memcpy(atari_dma_buffer
, data
, count
);
474 atari_dma_orig_addr
= data
;
475 addr
= atari_dma_phys_buffer
;
478 atari_dma_startaddr
= addr
; /* Needed for calculating residual later. */
480 /* Cache cleanup stuff: On writes, push any dirty cache out before sending
481 * it to the peripheral. (Must be done before DMA setup, since at least
482 * the ST-DMA begins to fill internal buffers right after setup. For
483 * reads, invalidate any cache, may be altered after DMA without CPU
486 * ++roman: For the Medusa, there's no need at all for that cache stuff,
487 * because the hardware does bus snooping (fine!).
489 dma_cache_maintenance(addr
, count
, dir
);
492 tt_scsi_dma
.dma_ctrl
= dir
;
493 SCSI_DMA_WRITE_P(dma_addr
, addr
);
494 SCSI_DMA_WRITE_P(dma_cnt
, count
);
495 tt_scsi_dma
.dma_ctrl
= dir
| 2;
496 } else { /* ! IS_A_TT */
499 SCSI_DMA_SETADR(addr
);
501 /* toggle direction bit to clear FIFO and set DMA direction */
503 st_dma
.dma_mode_status
= 0x90 | dir
;
504 st_dma
.dma_mode_status
= 0x90 | (dir
^ 0x100);
505 st_dma
.dma_mode_status
= 0x90 | dir
;
507 /* On writes, round up the transfer length to the next multiple of 512
508 * (see also comment at atari_dma_xfer_len()). */
509 st_dma
.fdc_acces_seccount
= (count
+ (dir
? 511 : 0)) >> 9;
511 st_dma
.dma_mode_status
= 0x10 | dir
;
513 /* need not restore value of dir, only boolean value is tested */
514 atari_dma_active
= 1;
520 static inline int atari_scsi_dma_recv_setup(struct NCR5380_hostdata
*hostdata
,
521 unsigned char *data
, int count
)
523 return atari_scsi_dma_setup(hostdata
, data
, count
, 0);
526 static inline int atari_scsi_dma_send_setup(struct NCR5380_hostdata
*hostdata
,
527 unsigned char *data
, int count
)
529 return atari_scsi_dma_setup(hostdata
, data
, count
, 1);
532 static int atari_scsi_dma_residual(struct NCR5380_hostdata
*hostdata
)
534 return atari_dma_residual
;
538 #define CMD_SURELY_BLOCK_MODE 0
539 #define CMD_SURELY_BYTE_MODE 1
540 #define CMD_MODE_UNKNOWN 2
542 static int falcon_classify_cmd(struct scsi_cmnd
*cmd
)
544 unsigned char opcode
= cmd
->cmnd
[0];
546 if (opcode
== READ_DEFECT_DATA
|| opcode
== READ_LONG
||
547 opcode
== READ_BUFFER
)
548 return CMD_SURELY_BYTE_MODE
;
549 else if (opcode
== READ_6
|| opcode
== READ_10
||
550 opcode
== 0xa8 /* READ_12 */ || opcode
== READ_REVERSE
||
551 opcode
== RECOVER_BUFFERED_DATA
) {
552 /* In case of a sequential-access target (tape), special care is
553 * needed here: The transfer is block-mode only if the 'fixed' bit is
555 if (cmd
->device
->type
== TYPE_TAPE
&& !(cmd
->cmnd
[1] & 1))
556 return CMD_SURELY_BYTE_MODE
;
558 return CMD_SURELY_BLOCK_MODE
;
560 return CMD_MODE_UNKNOWN
;
564 /* This function calculates the number of bytes that can be transferred via
565 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
566 * ST-DMA chip. There are only multiples of 512 bytes possible and max.
567 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
568 * possible on the Falcon, since that would require to program the DMA for
569 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
570 * the overrun problem, so this question is academic :-)
573 static int atari_scsi_dma_xfer_len(struct NCR5380_hostdata
*hostdata
,
574 struct scsi_cmnd
*cmd
)
576 int wanted_len
= cmd
->SCp
.this_residual
;
577 int possible_len
, limit
;
579 if (wanted_len
< DMA_MIN_SIZE
)
583 /* TT SCSI DMA can transfer arbitrary #bytes */
586 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
587 * 255*512 bytes, but this should be enough)
589 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
590 * that return a number of bytes which cannot be known beforehand. In this
591 * case, the given transfer length is an "allocation length". Now it
592 * can happen that this allocation length is a multiple of 512 bytes and
593 * the DMA is used. But if not n*512 bytes really arrive, some input data
594 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
595 * between commands that do block transfers and those that do byte
596 * transfers. But this isn't easy... there are lots of vendor specific
597 * commands, and the user can issue any command via the
598 * SCSI_IOCTL_SEND_COMMAND.
600 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
601 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
602 * and 3), the thing to do is obvious: allow any number of blocks via DMA
603 * or none. In case 2), we apply some heuristic: Byte mode is assumed if
604 * the transfer (allocation) length is < 1024, hoping that no cmd. not
605 * explicitly known as byte mode have such big allocation lengths...
606 * BTW, all the discussion above applies only to reads. DMA writes are
607 * unproblematic anyways, since the targets aborts the transfer after
608 * receiving a sufficient number of bytes.
610 * Another point: If the transfer is from/to an non-ST-RAM address, we
611 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
614 if (cmd
->sc_data_direction
== DMA_TO_DEVICE
) {
615 /* Write operation can always use the DMA, but the transfer size must
616 * be rounded up to the next multiple of 512 (atari_dma_setup() does
619 possible_len
= wanted_len
;
621 /* Read operations: if the wanted transfer length is not a multiple of
622 * 512, we cannot use DMA, since the ST-DMA cannot split transfers
623 * (no interrupt on DMA finished!)
625 if (wanted_len
& 0x1ff)
628 /* Now classify the command (see above) and decide whether it is
629 * allowed to do DMA at all */
630 switch (falcon_classify_cmd(cmd
)) {
631 case CMD_SURELY_BLOCK_MODE
:
632 possible_len
= wanted_len
;
634 case CMD_SURELY_BYTE_MODE
:
635 possible_len
= 0; /* DMA prohibited */
637 case CMD_MODE_UNKNOWN
:
639 /* For unknown commands assume block transfers if the transfer
640 * size/allocation length is >= 1024 */
641 possible_len
= (wanted_len
< 1024) ? 0 : wanted_len
;
647 /* Last step: apply the hard limit on DMA transfers */
648 limit
= (atari_dma_buffer
&& !STRAM_ADDR(virt_to_phys(cmd
->SCp
.ptr
))) ?
649 STRAM_BUFFER_SIZE
: 255*512;
650 if (possible_len
> limit
)
651 possible_len
= limit
;
653 if (possible_len
!= wanted_len
)
654 dprintk(NDEBUG_DMA
, "DMA transfer now %d bytes instead of %d\n",
655 possible_len
, wanted_len
);
661 /* NCR5380 register access functions
663 * There are separate functions for TT and Falcon, because the access
664 * methods are quite different. The calling macros NCR5380_read and
665 * NCR5380_write call these functions via function pointers.
668 static u8
atari_scsi_tt_reg_read(unsigned int reg
)
670 return tt_scsi_regp
[reg
* 2];
673 static void atari_scsi_tt_reg_write(unsigned int reg
, u8 value
)
675 tt_scsi_regp
[reg
* 2] = value
;
678 static u8
atari_scsi_falcon_reg_read(unsigned int reg
)
684 local_irq_save(flags
);
685 dma_wd
.dma_mode_status
= (u_short
)reg
;
686 result
= (u8
)dma_wd
.fdc_acces_seccount
;
687 local_irq_restore(flags
);
691 static void atari_scsi_falcon_reg_write(unsigned int reg
, u8 value
)
696 local_irq_save(flags
);
697 dma_wd
.dma_mode_status
= (u_short
)reg
;
698 dma_wd
.fdc_acces_seccount
= (u_short
)value
;
699 local_irq_restore(flags
);
705 static int atari_scsi_bus_reset(struct scsi_cmnd
*cmd
)
710 local_irq_save(flags
);
712 /* Abort a maybe active DMA transfer */
714 tt_scsi_dma
.dma_ctrl
= 0;
716 st_dma
.dma_mode_status
= 0x90;
717 atari_dma_active
= 0;
718 atari_dma_orig_addr
= NULL
;
721 rv
= NCR5380_bus_reset(cmd
);
723 /* The 5380 raises its IRQ line while _RST is active but the ST DMA
724 * "lock" has been released so this interrupt may end up handled by
725 * floppy or IDE driver (if one of them holds the lock). The NCR5380
726 * interrupt flag has been cleared already.
729 local_irq_restore(flags
);
734 #define DRV_MODULE_NAME "atari_scsi"
735 #define PFX DRV_MODULE_NAME ": "
737 static struct scsi_host_template atari_scsi_template
= {
738 .module
= THIS_MODULE
,
739 .proc_name
= DRV_MODULE_NAME
,
740 .name
= "Atari native SCSI",
741 .info
= atari_scsi_info
,
742 .queuecommand
= atari_scsi_queue_command
,
743 .eh_abort_handler
= atari_scsi_abort
,
744 .eh_bus_reset_handler
= atari_scsi_bus_reset
,
747 .use_clustering
= DISABLE_CLUSTERING
,
748 .cmd_size
= NCR5380_CMD_SIZE
,
751 static int __init
atari_scsi_probe(struct platform_device
*pdev
)
753 struct Scsi_Host
*instance
;
755 struct resource
*irq
;
758 irq
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
762 if (ATARIHW_PRESENT(TT_SCSI
)) {
763 atari_scsi_reg_read
= atari_scsi_tt_reg_read
;
764 atari_scsi_reg_write
= atari_scsi_tt_reg_write
;
766 atari_scsi_reg_read
= atari_scsi_falcon_reg_read
;
767 atari_scsi_reg_write
= atari_scsi_falcon_reg_write
;
770 if (ATARIHW_PRESENT(TT_SCSI
)) {
771 atari_scsi_template
.can_queue
= 16;
772 atari_scsi_template
.sg_tablesize
= SG_ALL
;
774 atari_scsi_template
.can_queue
= 1;
775 atari_scsi_template
.sg_tablesize
= SG_NONE
;
778 if (setup_can_queue
> 0)
779 atari_scsi_template
.can_queue
= setup_can_queue
;
781 if (setup_cmd_per_lun
> 0)
782 atari_scsi_template
.cmd_per_lun
= setup_cmd_per_lun
;
784 /* Leave sg_tablesize at 0 on a Falcon! */
785 if (ATARIHW_PRESENT(TT_SCSI
) && setup_sg_tablesize
>= 0)
786 atari_scsi_template
.sg_tablesize
= setup_sg_tablesize
;
788 if (setup_hostid
>= 0) {
789 atari_scsi_template
.this_id
= setup_hostid
& 7;
791 /* Test if a host id is set in the NVRam */
792 if (ATARIHW_PRESENT(TT_CLK
) && nvram_check_checksum()) {
793 unsigned char b
= nvram_read_byte(16);
795 /* Arbitration enabled? (for TOS)
796 * If yes, use configured host ID
799 atari_scsi_template
.this_id
= b
& 7;
803 /* If running on a Falcon and if there's TT-Ram (i.e., more than one
804 * memory block, since there's always ST-Ram in a Falcon), then
805 * allocate a STRAM_BUFFER_SIZE byte dribble buffer for transfers
806 * from/to alternative Ram.
808 if (ATARIHW_PRESENT(ST_SCSI
) && !ATARIHW_PRESENT(EXTD_DMA
) &&
809 m68k_num_memory
> 1) {
810 atari_dma_buffer
= atari_stram_alloc(STRAM_BUFFER_SIZE
, "SCSI");
811 if (!atari_dma_buffer
) {
812 pr_err(PFX
"can't allocate ST-RAM double buffer\n");
815 atari_dma_phys_buffer
= atari_stram_to_phys(atari_dma_buffer
);
816 atari_dma_orig_addr
= 0;
819 instance
= scsi_host_alloc(&atari_scsi_template
,
820 sizeof(struct NCR5380_hostdata
));
826 instance
->irq
= irq
->start
;
828 host_flags
|= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP
;
829 host_flags
|= setup_toshiba_delay
> 0 ? FLAG_TOSHIBA_DELAY
: 0;
831 error
= NCR5380_init(instance
, host_flags
);
836 error
= request_irq(instance
->irq
, scsi_tt_intr
, 0,
837 "NCR5380", instance
);
839 pr_err(PFX
"request irq %d failed, aborting\n",
843 tt_mfp
.active_edge
|= 0x80; /* SCSI int on L->H */
845 tt_scsi_dma
.dma_ctrl
= 0;
846 atari_dma_residual
= 0;
848 /* While the read overruns (described by Drew Eckhardt in
849 * NCR5380.c) never happened on TTs, they do in fact on the
850 * Medusa (This was the cause why SCSI didn't work right for
851 * so long there.) Since handling the overruns slows down
852 * a bit, I turned the #ifdef's into a runtime condition.
854 * In principle it should be sufficient to do max. 1 byte with
855 * PIO, but there is another problem on the Medusa with the DMA
856 * rest data register. So read_overruns is currently set
857 * to 4 to avoid having transfers that aren't a multiple of 4.
858 * If the rest data bug is fixed, this can be lowered to 1.
860 if (MACH_IS_MEDUSA
) {
861 struct NCR5380_hostdata
*hostdata
=
862 shost_priv(instance
);
864 hostdata
->read_overruns
= 4;
867 /* Nothing to do for the interrupt: the ST-DMA is initialized
870 atari_dma_residual
= 0;
871 atari_dma_active
= 0;
872 atari_dma_stram_mask
= (ATARIHW_PRESENT(EXTD_DMA
) ? 0x00000000
876 NCR5380_maybe_reset_bus(instance
);
878 error
= scsi_add_host(instance
, NULL
);
882 platform_set_drvdata(pdev
, instance
);
884 scsi_scan_host(instance
);
889 free_irq(instance
->irq
, instance
);
891 NCR5380_exit(instance
);
893 scsi_host_put(instance
);
895 if (atari_dma_buffer
)
896 atari_stram_free(atari_dma_buffer
);
900 static int __exit
atari_scsi_remove(struct platform_device
*pdev
)
902 struct Scsi_Host
*instance
= platform_get_drvdata(pdev
);
904 scsi_remove_host(instance
);
906 free_irq(instance
->irq
, instance
);
907 NCR5380_exit(instance
);
908 scsi_host_put(instance
);
909 if (atari_dma_buffer
)
910 atari_stram_free(atari_dma_buffer
);
914 static struct platform_driver atari_scsi_driver
= {
915 .remove
= __exit_p(atari_scsi_remove
),
917 .name
= DRV_MODULE_NAME
,
921 module_platform_driver_probe(atari_scsi_driver
, atari_scsi_probe
);
923 MODULE_ALIAS("platform:" DRV_MODULE_NAME
);
924 MODULE_LICENSE("GPL");