1 // SPDX-License-Identifier: GPL-2.0-only
3 * SCSI low-level driver for the 53c94 SCSI bus adaptor found
4 * on Power Macintosh computers, controlling the external SCSI chain.
5 * We assume the 53c94 is connected to a DBDMA (descriptor-based DMA)
8 * Paul Mackerras, August 1996.
9 * Copyright (C) 1996 Paul Mackerras.
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/types.h>
14 #include <linux/string.h>
15 #include <linux/slab.h>
16 #include <linux/blkdev.h>
17 #include <linux/proc_fs.h>
18 #include <linux/stat.h>
19 #include <linux/spinlock.h>
20 #include <linux/interrupt.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <asm/dbdma.h>
25 #include <asm/pgtable.h>
27 #include <asm/macio.h>
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_cmnd.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_host.h>
45 struct mac53c94_regs __iomem
*regs
;
47 struct dbdma_regs __iomem
*dma
;
50 struct Scsi_Host
*host
;
51 struct scsi_cmnd
*request_q
;
52 struct scsi_cmnd
*request_qtail
;
53 struct scsi_cmnd
*current_req
; /* req we're currently working on */
54 enum fsc_phase phase
; /* what we're currently trying to do */
55 struct dbdma_cmd
*dma_cmds
; /* space for dbdma commands, aligned */
59 struct macio_dev
*mdev
;
62 static void mac53c94_init(struct fsc_state
*);
63 static void mac53c94_start(struct fsc_state
*);
64 static void mac53c94_interrupt(int, void *);
65 static irqreturn_t
do_mac53c94_interrupt(int, void *);
66 static void cmd_done(struct fsc_state
*, int result
);
67 static void set_dma_cmds(struct fsc_state
*, struct scsi_cmnd
*);
70 static int mac53c94_queue_lck(struct scsi_cmnd
*cmd
, void (*done
)(struct scsi_cmnd
*))
72 struct fsc_state
*state
;
75 if (cmd
->sc_data_direction
== DMA_TO_DEVICE
) {
77 printk(KERN_DEBUG
"mac53c94_queue %p: command is", cmd
);
78 for (i
= 0; i
< cmd
->cmd_len
; ++i
)
79 printk(KERN_CONT
" %.2x", cmd
->cmnd
[i
]);
80 printk(KERN_CONT
"\n");
81 printk(KERN_DEBUG
"use_sg=%d request_bufflen=%d request_buffer=%p\n",
82 scsi_sg_count(cmd
), scsi_bufflen(cmd
), scsi_sglist(cmd
));
86 cmd
->scsi_done
= done
;
87 cmd
->host_scribble
= NULL
;
89 state
= (struct fsc_state
*) cmd
->device
->host
->hostdata
;
91 if (state
->request_q
== NULL
)
92 state
->request_q
= cmd
;
94 state
->request_qtail
->host_scribble
= (void *) cmd
;
95 state
->request_qtail
= cmd
;
97 if (state
->phase
== idle
)
98 mac53c94_start(state
);
103 static DEF_SCSI_QCMD(mac53c94_queue
)
105 static int mac53c94_host_reset(struct scsi_cmnd
*cmd
)
107 struct fsc_state
*state
= (struct fsc_state
*) cmd
->device
->host
->hostdata
;
108 struct mac53c94_regs __iomem
*regs
= state
->regs
;
109 struct dbdma_regs __iomem
*dma
= state
->dma
;
112 spin_lock_irqsave(cmd
->device
->host
->host_lock
, flags
);
114 writel((RUN
|PAUSE
|FLUSH
|WAKE
) << 16, &dma
->control
);
115 writeb(CMD_SCSI_RESET
, ®s
->command
); /* assert RST */
116 udelay(100); /* leave it on for a while (>= 25us) */
117 writeb(CMD_RESET
, ®s
->command
);
119 mac53c94_init(state
);
120 writeb(CMD_NOP
, ®s
->command
);
122 spin_unlock_irqrestore(cmd
->device
->host
->host_lock
, flags
);
126 static void mac53c94_init(struct fsc_state
*state
)
128 struct mac53c94_regs __iomem
*regs
= state
->regs
;
129 struct dbdma_regs __iomem
*dma
= state
->dma
;
132 writeb(state
->host
->this_id
| CF1_PAR_ENABLE
, ®s
->config1
);
133 writeb(TIMO_VAL(250), ®s
->sel_timeout
); /* 250ms */
134 writeb(CLKF_VAL(state
->clk_freq
), ®s
->clk_factor
);
135 writeb(CF2_FEATURE_EN
, ®s
->config2
);
136 writeb(0, ®s
->config3
);
137 writeb(0, ®s
->sync_period
);
138 writeb(0, ®s
->sync_offset
);
139 x
= readb(®s
->interrupt
);
140 writel((RUN
|PAUSE
|FLUSH
|WAKE
) << 16, &dma
->control
);
144 * Start the next command for a 53C94.
145 * Should be called with interrupts disabled.
147 static void mac53c94_start(struct fsc_state
*state
)
149 struct scsi_cmnd
*cmd
;
150 struct mac53c94_regs __iomem
*regs
= state
->regs
;
153 if (state
->phase
!= idle
|| state
->current_req
!= NULL
)
154 panic("inappropriate mac53c94_start (state=%p)", state
);
155 if (state
->request_q
== NULL
)
157 state
->current_req
= cmd
= state
->request_q
;
158 state
->request_q
= (struct scsi_cmnd
*) cmd
->host_scribble
;
161 writeb(0, ®s
->count_lo
);
162 writeb(0, ®s
->count_mid
);
163 writeb(0, ®s
->count_hi
);
164 writeb(CMD_NOP
+ CMD_DMA_MODE
, ®s
->command
);
166 writeb(CMD_FLUSH
, ®s
->command
);
168 writeb(cmd
->device
->id
, ®s
->dest_id
);
169 writeb(0, ®s
->sync_period
);
170 writeb(0, ®s
->sync_offset
);
172 /* load the command into the FIFO */
173 for (i
= 0; i
< cmd
->cmd_len
; ++i
)
174 writeb(cmd
->cmnd
[i
], ®s
->fifo
);
176 /* do select without ATN XXX */
177 writeb(CMD_SELECT
, ®s
->command
);
178 state
->phase
= selecting
;
180 set_dma_cmds(state
, cmd
);
183 static irqreturn_t
do_mac53c94_interrupt(int irq
, void *dev_id
)
186 struct Scsi_Host
*dev
= ((struct fsc_state
*) dev_id
)->current_req
->device
->host
;
188 spin_lock_irqsave(dev
->host_lock
, flags
);
189 mac53c94_interrupt(irq
, dev_id
);
190 spin_unlock_irqrestore(dev
->host_lock
, flags
);
194 static void mac53c94_interrupt(int irq
, void *dev_id
)
196 struct fsc_state
*state
= (struct fsc_state
*) dev_id
;
197 struct mac53c94_regs __iomem
*regs
= state
->regs
;
198 struct dbdma_regs __iomem
*dma
= state
->dma
;
199 struct scsi_cmnd
*cmd
= state
->current_req
;
200 int nb
, stat
, seq
, intr
;
201 static int mac53c94_errors
;
204 * Apparently, reading the interrupt register unlatches
205 * the status and sequence step registers.
207 seq
= readb(®s
->seqstep
);
208 stat
= readb(®s
->status
);
209 intr
= readb(®s
->interrupt
);
212 printk(KERN_DEBUG
"mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
213 intr
, stat
, seq
, state
->phase
);
216 if (intr
& INTR_RESET
) {
217 /* SCSI bus was reset */
218 printk(KERN_INFO
"external SCSI bus reset detected\n");
219 writeb(CMD_NOP
, ®s
->command
);
220 writel(RUN
<< 16, &dma
->control
); /* stop dma */
221 cmd_done(state
, DID_RESET
<< 16);
224 if (intr
& INTR_ILL_CMD
) {
225 printk(KERN_ERR
"53c94: invalid cmd, intr=%x stat=%x seq=%x phase=%d\n",
226 intr
, stat
, seq
, state
->phase
);
227 cmd_done(state
, DID_ERROR
<< 16);
230 if (stat
& STAT_ERROR
) {
232 /* XXX these seem to be harmless? */
233 printk("53c94: bad error, intr=%x stat=%x seq=%x phase=%d\n",
234 intr
, stat
, seq
, state
->phase
);
237 writeb(CMD_NOP
+ CMD_DMA_MODE
, ®s
->command
);
240 printk(KERN_DEBUG
"53c94: interrupt with no command active?\n");
243 if (stat
& STAT_PARITY
) {
244 printk(KERN_ERR
"mac53c94: parity error\n");
245 cmd_done(state
, DID_PARITY
<< 16);
248 switch (state
->phase
) {
250 if (intr
& INTR_DISCONNECT
) {
251 /* selection timed out */
252 cmd_done(state
, DID_BAD_TARGET
<< 16);
255 if (intr
!= INTR_BUS_SERV
+ INTR_DONE
) {
256 printk(KERN_DEBUG
"got intr %x during selection\n", intr
);
257 cmd_done(state
, DID_ERROR
<< 16);
260 if ((seq
& SS_MASK
) != SS_DONE
) {
261 printk(KERN_DEBUG
"seq step %x after command\n", seq
);
262 cmd_done(state
, DID_ERROR
<< 16);
265 writeb(CMD_NOP
, ®s
->command
);
266 /* set DMA controller going if any data to transfer */
267 if ((stat
& (STAT_MSG
|STAT_CD
)) == 0
268 && (scsi_sg_count(cmd
) > 0 || scsi_bufflen(cmd
))) {
269 nb
= cmd
->SCp
.this_residual
;
272 cmd
->SCp
.this_residual
-= nb
;
273 writeb(nb
, ®s
->count_lo
);
274 writeb(nb
>> 8, ®s
->count_mid
);
275 writeb(CMD_DMA_MODE
+ CMD_NOP
, ®s
->command
);
276 writel(virt_to_phys(state
->dma_cmds
), &dma
->cmdptr
);
277 writel((RUN
<< 16) | RUN
, &dma
->control
);
278 writeb(CMD_DMA_MODE
+ CMD_XFER_DATA
, ®s
->command
);
279 state
->phase
= dataing
;
281 } else if ((stat
& STAT_PHASE
) == STAT_CD
+ STAT_IO
) {
282 /* up to status phase already */
283 writeb(CMD_I_COMPLETE
, ®s
->command
);
284 state
->phase
= completing
;
286 printk(KERN_DEBUG
"in unexpected phase %x after cmd\n",
288 cmd_done(state
, DID_ERROR
<< 16);
294 if (intr
!= INTR_BUS_SERV
) {
295 printk(KERN_DEBUG
"got intr %x before status\n", intr
);
296 cmd_done(state
, DID_ERROR
<< 16);
299 if (cmd
->SCp
.this_residual
!= 0
300 && (stat
& (STAT_MSG
|STAT_CD
)) == 0) {
301 /* Set up the count regs to transfer more */
302 nb
= cmd
->SCp
.this_residual
;
305 cmd
->SCp
.this_residual
-= nb
;
306 writeb(nb
, ®s
->count_lo
);
307 writeb(nb
>> 8, ®s
->count_mid
);
308 writeb(CMD_DMA_MODE
+ CMD_NOP
, ®s
->command
);
309 writeb(CMD_DMA_MODE
+ CMD_XFER_DATA
, ®s
->command
);
312 if ((stat
& STAT_PHASE
) != STAT_CD
+ STAT_IO
) {
313 printk(KERN_DEBUG
"intr %x before data xfer complete\n", intr
);
315 writel(RUN
<< 16, &dma
->control
); /* stop dma */
317 /* should check dma status */
318 writeb(CMD_I_COMPLETE
, ®s
->command
);
319 state
->phase
= completing
;
322 if (intr
!= INTR_DONE
) {
323 printk(KERN_DEBUG
"got intr %x on completion\n", intr
);
324 cmd_done(state
, DID_ERROR
<< 16);
327 cmd
->SCp
.Status
= readb(®s
->fifo
);
328 cmd
->SCp
.Message
= readb(®s
->fifo
);
329 cmd
->result
= CMD_ACCEPT_MSG
;
330 writeb(CMD_ACCEPT_MSG
, ®s
->command
);
331 state
->phase
= busfreeing
;
334 if (intr
!= INTR_DISCONNECT
) {
335 printk(KERN_DEBUG
"got intr %x when expected disconnect\n", intr
);
337 cmd_done(state
, (DID_OK
<< 16) + (cmd
->SCp
.Message
<< 8)
341 printk(KERN_DEBUG
"don't know about phase %d\n", state
->phase
);
345 static void cmd_done(struct fsc_state
*state
, int result
)
347 struct scsi_cmnd
*cmd
;
349 cmd
= state
->current_req
;
351 cmd
->result
= result
;
352 (*cmd
->scsi_done
)(cmd
);
353 state
->current_req
= NULL
;
356 mac53c94_start(state
);
360 * Set up DMA commands for transferring data.
362 static void set_dma_cmds(struct fsc_state
*state
, struct scsi_cmnd
*cmd
)
364 int i
, dma_cmd
, total
, nseg
;
365 struct scatterlist
*scl
;
366 struct dbdma_cmd
*dcmds
;
370 nseg
= scsi_dma_map(cmd
);
375 dma_cmd
= cmd
->sc_data_direction
== DMA_TO_DEVICE
?
376 OUTPUT_MORE
: INPUT_MORE
;
377 dcmds
= state
->dma_cmds
;
380 scsi_for_each_sg(cmd
, scl
, nseg
, i
) {
381 dma_addr
= sg_dma_address(scl
);
382 dma_len
= sg_dma_len(scl
);
383 if (dma_len
> 0xffff)
384 panic("mac53c94: scatterlist element >= 64k");
386 dcmds
->req_count
= cpu_to_le16(dma_len
);
387 dcmds
->command
= cpu_to_le16(dma_cmd
);
388 dcmds
->phy_addr
= cpu_to_le32(dma_addr
);
389 dcmds
->xfer_status
= 0;
393 dma_cmd
+= OUTPUT_LAST
- OUTPUT_MORE
;
394 dcmds
[-1].command
= cpu_to_le16(dma_cmd
);
395 dcmds
->command
= cpu_to_le16(DBDMA_STOP
);
396 cmd
->SCp
.this_residual
= total
;
399 static struct scsi_host_template mac53c94_template
= {
400 .proc_name
= "53c94",
402 .queuecommand
= mac53c94_queue
,
403 .eh_host_reset_handler
= mac53c94_host_reset
,
406 .sg_tablesize
= SG_ALL
,
407 .max_segment_size
= 65535,
410 static int mac53c94_probe(struct macio_dev
*mdev
, const struct of_device_id
*match
)
412 struct device_node
*node
= macio_get_of_node(mdev
);
413 struct pci_dev
*pdev
= macio_get_pci_dev(mdev
);
414 struct fsc_state
*state
;
415 struct Scsi_Host
*host
;
417 const unsigned char *clkprop
;
418 int proplen
, rc
= -ENODEV
;
420 if (macio_resource_count(mdev
) != 2 || macio_irq_count(mdev
) != 2) {
421 printk(KERN_ERR
"mac53c94: expected 2 addrs and intrs"
423 macio_resource_count(mdev
), macio_irq_count(mdev
));
427 if (macio_request_resources(mdev
, "mac53c94") != 0) {
428 printk(KERN_ERR
"mac53c94: unable to request memory resources");
432 host
= scsi_host_alloc(&mac53c94_template
, sizeof(struct fsc_state
));
434 printk(KERN_ERR
"mac53c94: couldn't register host");
439 state
= (struct fsc_state
*) host
->hostdata
;
440 macio_set_drvdata(mdev
, state
);
445 state
->regs
= (struct mac53c94_regs __iomem
*)
446 ioremap(macio_resource_start(mdev
, 0), 0x1000);
447 state
->intr
= macio_irq(mdev
, 0);
448 state
->dma
= (struct dbdma_regs __iomem
*)
449 ioremap(macio_resource_start(mdev
, 1), 0x1000);
450 state
->dmaintr
= macio_irq(mdev
, 1);
451 if (state
->regs
== NULL
|| state
->dma
== NULL
) {
452 printk(KERN_ERR
"mac53c94: ioremap failed for %pOF\n", node
);
456 clkprop
= of_get_property(node
, "clock-frequency", &proplen
);
457 if (clkprop
== NULL
|| proplen
!= sizeof(int)) {
458 printk(KERN_ERR
"%pOF: can't get clock frequency, "
459 "assuming 25MHz\n", node
);
460 state
->clk_freq
= 25000000;
462 state
->clk_freq
= *(int *)clkprop
;
464 /* Space for dma command list: +1 for stop command,
465 * +1 to allow for aligning.
466 * XXX FIXME: Use DMA consistent routines
468 dma_cmd_space
= kmalloc_array(host
->sg_tablesize
+ 2,
469 sizeof(struct dbdma_cmd
),
471 if (dma_cmd_space
== 0) {
472 printk(KERN_ERR
"mac53c94: couldn't allocate dma "
473 "command space for %pOF\n", node
);
477 state
->dma_cmds
= (struct dbdma_cmd
*)DBDMA_ALIGN(dma_cmd_space
);
478 memset(state
->dma_cmds
, 0, (host
->sg_tablesize
+ 1)
479 * sizeof(struct dbdma_cmd
));
480 state
->dma_cmd_space
= dma_cmd_space
;
482 mac53c94_init(state
);
484 if (request_irq(state
->intr
, do_mac53c94_interrupt
, 0, "53C94",state
)) {
485 printk(KERN_ERR
"mac53C94: can't get irq %d for %pOF\n",
490 rc
= scsi_add_host(host
, &mdev
->ofdev
.dev
);
492 goto out_release_irq
;
494 scsi_scan_host(host
);
498 free_irq(state
->intr
, state
);
500 kfree(state
->dma_cmd_space
);
502 if (state
->dma
!= NULL
)
504 if (state
->regs
!= NULL
)
505 iounmap(state
->regs
);
508 macio_release_resources(mdev
);
513 static int mac53c94_remove(struct macio_dev
*mdev
)
515 struct fsc_state
*fp
= (struct fsc_state
*)macio_get_drvdata(mdev
);
516 struct Scsi_Host
*host
= fp
->host
;
518 scsi_remove_host(host
);
520 free_irq(fp
->intr
, fp
);
526 kfree(fp
->dma_cmd_space
);
530 macio_release_resources(mdev
);
536 static struct of_device_id mac53c94_match
[] =
543 MODULE_DEVICE_TABLE (of
, mac53c94_match
);
545 static struct macio_driver mac53c94_driver
=
549 .owner
= THIS_MODULE
,
550 .of_match_table
= mac53c94_match
,
552 .probe
= mac53c94_probe
,
553 .remove
= mac53c94_remove
,
557 static int __init
init_mac53c94(void)
559 return macio_register_driver(&mac53c94_driver
);
562 static void __exit
exit_mac53c94(void)
564 return macio_unregister_driver(&mac53c94_driver
);
567 module_init(init_mac53c94
);
568 module_exit(exit_mac53c94
);
570 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
571 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
572 MODULE_LICENSE("GPL");