GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / scsi / mac53c94.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
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)
6  * controller.
7  *
8  * Paul Mackerras, August 1996.
9  * Copyright (C) 1996 Paul Mackerras.
10  */
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 <linux/pgtable.h>
24 #include <asm/dbdma.h>
25 #include <asm/io.h>
26 #include <asm/prom.h>
27 #include <asm/macio.h>
28
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_cmnd.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_host.h>
33
34 #include "mac53c94.h"
35
36 enum fsc_phase {
37         idle,
38         selecting,
39         dataing,
40         completing,
41         busfreeing,
42 };
43
44 struct fsc_state {
45         struct  mac53c94_regs __iomem *regs;
46         int     intr;
47         struct  dbdma_regs __iomem *dma;
48         int     dmaintr;
49         int     clk_freq;
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 */
56         void    *dma_cmd_space;
57         struct  pci_dev *pdev;
58         dma_addr_t dma_addr;
59         struct macio_dev *mdev;
60 };
61
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 *);
68
69
70 static int mac53c94_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
71 {
72         struct fsc_state *state;
73
74 #if 0
75         if (cmd->sc_data_direction == DMA_TO_DEVICE) {
76                 int i;
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));
83         }
84 #endif
85
86         cmd->scsi_done = done;
87         cmd->host_scribble = NULL;
88
89         state = (struct fsc_state *) cmd->device->host->hostdata;
90
91         if (state->request_q == NULL)
92                 state->request_q = cmd;
93         else
94                 state->request_qtail->host_scribble = (void *) cmd;
95         state->request_qtail = cmd;
96
97         if (state->phase == idle)
98                 mac53c94_start(state);
99
100         return 0;
101 }
102
103 static DEF_SCSI_QCMD(mac53c94_queue)
104
105 static int mac53c94_host_reset(struct scsi_cmnd *cmd)
106 {
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;
110         unsigned long flags;
111
112         spin_lock_irqsave(cmd->device->host->host_lock, flags);
113
114         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
115         writeb(CMD_SCSI_RESET, &regs->command); /* assert RST */
116         udelay(100);                    /* leave it on for a while (>= 25us) */
117         writeb(CMD_RESET, &regs->command);
118         udelay(20);
119         mac53c94_init(state);
120         writeb(CMD_NOP, &regs->command);
121
122         spin_unlock_irqrestore(cmd->device->host->host_lock, flags);
123         return SUCCESS;
124 }
125
126 static void mac53c94_init(struct fsc_state *state)
127 {
128         struct mac53c94_regs __iomem *regs = state->regs;
129         struct dbdma_regs __iomem *dma = state->dma;
130         int x;
131
132         writeb(state->host->this_id | CF1_PAR_ENABLE, &regs->config1);
133         writeb(TIMO_VAL(250), &regs->sel_timeout);      /* 250ms */
134         writeb(CLKF_VAL(state->clk_freq), &regs->clk_factor);
135         writeb(CF2_FEATURE_EN, &regs->config2);
136         writeb(0, &regs->config3);
137         writeb(0, &regs->sync_period);
138         writeb(0, &regs->sync_offset);
139         x = readb(&regs->interrupt);
140         writel((RUN|PAUSE|FLUSH|WAKE) << 16, &dma->control);
141 }
142
143 /*
144  * Start the next command for a 53C94.
145  * Should be called with interrupts disabled.
146  */
147 static void mac53c94_start(struct fsc_state *state)
148 {
149         struct scsi_cmnd *cmd;
150         struct mac53c94_regs __iomem *regs = state->regs;
151         int i;
152
153         if (state->phase != idle || state->current_req != NULL)
154                 panic("inappropriate mac53c94_start (state=%p)", state);
155         if (state->request_q == NULL)
156                 return;
157         state->current_req = cmd = state->request_q;
158         state->request_q = (struct scsi_cmnd *) cmd->host_scribble;
159
160         /* Off we go */
161         writeb(0, &regs->count_lo);
162         writeb(0, &regs->count_mid);
163         writeb(0, &regs->count_hi);
164         writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
165         udelay(1);
166         writeb(CMD_FLUSH, &regs->command);
167         udelay(1);
168         writeb(cmd->device->id, &regs->dest_id);
169         writeb(0, &regs->sync_period);
170         writeb(0, &regs->sync_offset);
171
172         /* load the command into the FIFO */
173         for (i = 0; i < cmd->cmd_len; ++i)
174                 writeb(cmd->cmnd[i], &regs->fifo);
175
176         /* do select without ATN XXX */
177         writeb(CMD_SELECT, &regs->command);
178         state->phase = selecting;
179
180         set_dma_cmds(state, cmd);
181 }
182
183 static irqreturn_t do_mac53c94_interrupt(int irq, void *dev_id)
184 {
185         unsigned long flags;
186         struct Scsi_Host *dev = ((struct fsc_state *) dev_id)->current_req->device->host;
187         
188         spin_lock_irqsave(dev->host_lock, flags);
189         mac53c94_interrupt(irq, dev_id);
190         spin_unlock_irqrestore(dev->host_lock, flags);
191         return IRQ_HANDLED;
192 }
193
194 static void mac53c94_interrupt(int irq, void *dev_id)
195 {
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;
202
203         /*
204          * Apparently, reading the interrupt register unlatches
205          * the status and sequence step registers.
206          */
207         seq = readb(&regs->seqstep);
208         stat = readb(&regs->status);
209         intr = readb(&regs->interrupt);
210
211 #if 0
212         printk(KERN_DEBUG "mac53c94_intr, intr=%x stat=%x seq=%x phase=%d\n",
213                intr, stat, seq, state->phase);
214 #endif
215
216         if (intr & INTR_RESET) {
217                 /* SCSI bus was reset */
218                 printk(KERN_INFO "external SCSI bus reset detected\n");
219                 writeb(CMD_NOP, &regs->command);
220                 writel(RUN << 16, &dma->control);       /* stop dma */
221                 cmd_done(state, DID_RESET << 16);
222                 return;
223         }
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);
228                 return;
229         }
230         if (stat & STAT_ERROR) {
231 #if 0
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);
235 #endif
236                 ++mac53c94_errors;
237                 writeb(CMD_NOP + CMD_DMA_MODE, &regs->command);
238         }
239         if (cmd == 0) {
240                 printk(KERN_DEBUG "53c94: interrupt with no command active?\n");
241                 return;
242         }
243         if (stat & STAT_PARITY) {
244                 printk(KERN_ERR "mac53c94: parity error\n");
245                 cmd_done(state, DID_PARITY << 16);
246                 return;
247         }
248         switch (state->phase) {
249         case selecting:
250                 if (intr & INTR_DISCONNECT) {
251                         /* selection timed out */
252                         cmd_done(state, DID_BAD_TARGET << 16);
253                         return;
254                 }
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);
258                         return;
259                 }
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);
263                         return;
264                 }
265                 writeb(CMD_NOP, &regs->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;
270                         if (nb > 0xfff0)
271                                 nb = 0xfff0;
272                         cmd->SCp.this_residual -= nb;
273                         writeb(nb, &regs->count_lo);
274                         writeb(nb >> 8, &regs->count_mid);
275                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->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, &regs->command);
279                         state->phase = dataing;
280                         break;
281                 } else if ((stat & STAT_PHASE) == STAT_CD + STAT_IO) {
282                         /* up to status phase already */
283                         writeb(CMD_I_COMPLETE, &regs->command);
284                         state->phase = completing;
285                 } else {
286                         printk(KERN_DEBUG "in unexpected phase %x after cmd\n",
287                                stat & STAT_PHASE);
288                         cmd_done(state, DID_ERROR << 16);
289                         return;
290                 }
291                 break;
292
293         case dataing:
294                 if (intr != INTR_BUS_SERV) {
295                         printk(KERN_DEBUG "got intr %x before status\n", intr);
296                         cmd_done(state, DID_ERROR << 16);
297                         return;
298                 }
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;
303                         if (nb > 0xfff0)
304                                 nb = 0xfff0;
305                         cmd->SCp.this_residual -= nb;
306                         writeb(nb, &regs->count_lo);
307                         writeb(nb >> 8, &regs->count_mid);
308                         writeb(CMD_DMA_MODE + CMD_NOP, &regs->command);
309                         writeb(CMD_DMA_MODE + CMD_XFER_DATA, &regs->command);
310                         break;
311                 }
312                 if ((stat & STAT_PHASE) != STAT_CD + STAT_IO) {
313                         printk(KERN_DEBUG "intr %x before data xfer complete\n", intr);
314                 }
315                 writel(RUN << 16, &dma->control);       /* stop dma */
316                 scsi_dma_unmap(cmd);
317                 /* should check dma status */
318                 writeb(CMD_I_COMPLETE, &regs->command);
319                 state->phase = completing;
320                 break;
321         case completing:
322                 if (intr != INTR_DONE) {
323                         printk(KERN_DEBUG "got intr %x on completion\n", intr);
324                         cmd_done(state, DID_ERROR << 16);
325                         return;
326                 }
327                 cmd->SCp.Status = readb(&regs->fifo);
328                 cmd->SCp.Message = readb(&regs->fifo);
329                 cmd->result = CMD_ACCEPT_MSG;
330                 writeb(CMD_ACCEPT_MSG, &regs->command);
331                 state->phase = busfreeing;
332                 break;
333         case busfreeing:
334                 if (intr != INTR_DISCONNECT) {
335                         printk(KERN_DEBUG "got intr %x when expected disconnect\n", intr);
336                 }
337                 cmd_done(state, (DID_OK << 16) + (cmd->SCp.Message << 8)
338                          + cmd->SCp.Status);
339                 break;
340         default:
341                 printk(KERN_DEBUG "don't know about phase %d\n", state->phase);
342         }
343 }
344
345 static void cmd_done(struct fsc_state *state, int result)
346 {
347         struct scsi_cmnd *cmd;
348
349         cmd = state->current_req;
350         if (cmd != 0) {
351                 cmd->result = result;
352                 (*cmd->scsi_done)(cmd);
353                 state->current_req = NULL;
354         }
355         state->phase = idle;
356         mac53c94_start(state);
357 }
358
359 /*
360  * Set up DMA commands for transferring data.
361  */
362 static void set_dma_cmds(struct fsc_state *state, struct scsi_cmnd *cmd)
363 {
364         int i, dma_cmd, total, nseg;
365         struct scatterlist *scl;
366         struct dbdma_cmd *dcmds;
367         dma_addr_t dma_addr;
368         u32 dma_len;
369
370         nseg = scsi_dma_map(cmd);
371         BUG_ON(nseg < 0);
372         if (!nseg)
373                 return;
374
375         dma_cmd = cmd->sc_data_direction == DMA_TO_DEVICE ?
376                         OUTPUT_MORE : INPUT_MORE;
377         dcmds = state->dma_cmds;
378         total = 0;
379
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");
385                 total += dma_len;
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;
390                 ++dcmds;
391         }
392
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;
397 }
398
399 static struct scsi_host_template mac53c94_template = {
400         .proc_name      = "53c94",
401         .name           = "53C94",
402         .queuecommand   = mac53c94_queue,
403         .eh_host_reset_handler = mac53c94_host_reset,
404         .can_queue      = 1,
405         .this_id        = 7,
406         .sg_tablesize   = SG_ALL,
407         .max_segment_size = 65535,
408 };
409
410 static int mac53c94_probe(struct macio_dev *mdev, const struct of_device_id *match)
411 {
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;
416         void *dma_cmd_space;
417         const unsigned char *clkprop;
418         int proplen, rc = -ENODEV;
419
420         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
421                 printk(KERN_ERR "mac53c94: expected 2 addrs and intrs"
422                        " (got %d/%d)\n",
423                        macio_resource_count(mdev), macio_irq_count(mdev));
424                 return -ENODEV;
425         }
426
427         if (macio_request_resources(mdev, "mac53c94") != 0) {
428                 printk(KERN_ERR "mac53c94: unable to request memory resources");
429                 return -EBUSY;
430         }
431
432         host = scsi_host_alloc(&mac53c94_template, sizeof(struct fsc_state));
433         if (host == NULL) {
434                 printk(KERN_ERR "mac53c94: couldn't register host");
435                 rc = -ENOMEM;
436                 goto out_release;
437         }
438
439         state = (struct fsc_state *) host->hostdata;
440         macio_set_drvdata(mdev, state);
441         state->host = host;
442         state->pdev = pdev;
443         state->mdev = mdev;
444
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);
453                 goto out_free;
454         }
455
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;
461         } else
462                 state->clk_freq = *(int *)clkprop;
463
464         /* Space for dma command list: +1 for stop command,
465          * +1 to allow for aligning.
466          * XXX FIXME: Use DMA consistent routines
467          */
468         dma_cmd_space = kmalloc_array(host->sg_tablesize + 2,
469                                              sizeof(struct dbdma_cmd),
470                                              GFP_KERNEL);
471         if (dma_cmd_space == 0) {
472                 printk(KERN_ERR "mac53c94: couldn't allocate dma "
473                        "command space for %pOF\n", node);
474                 rc = -ENOMEM;
475                 goto out_free;
476         }
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;
481
482         mac53c94_init(state);
483
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",
486                        state->intr, node);
487                 goto out_free_dma;
488         }
489
490         rc = scsi_add_host(host, &mdev->ofdev.dev);
491         if (rc != 0)
492                 goto out_release_irq;
493
494         scsi_scan_host(host);
495         return 0;
496
497  out_release_irq:
498         free_irq(state->intr, state);
499  out_free_dma:
500         kfree(state->dma_cmd_space);
501  out_free:
502         if (state->dma != NULL)
503                 iounmap(state->dma);
504         if (state->regs != NULL)
505                 iounmap(state->regs);
506         scsi_host_put(host);
507  out_release:
508         macio_release_resources(mdev);
509
510         return rc;
511 }
512
513 static int mac53c94_remove(struct macio_dev *mdev)
514 {
515         struct fsc_state *fp = (struct fsc_state *)macio_get_drvdata(mdev);
516         struct Scsi_Host *host = fp->host;
517
518         scsi_remove_host(host);
519
520         free_irq(fp->intr, fp);
521
522         if (fp->regs)
523                 iounmap(fp->regs);
524         if (fp->dma)
525                 iounmap(fp->dma);
526         kfree(fp->dma_cmd_space);
527
528         scsi_host_put(host);
529
530         macio_release_resources(mdev);
531
532         return 0;
533 }
534
535
536 static struct of_device_id mac53c94_match[] = 
537 {
538         {
539         .name           = "53c94",
540         },
541         {},
542 };
543 MODULE_DEVICE_TABLE (of, mac53c94_match);
544
545 static struct macio_driver mac53c94_driver = 
546 {
547         .driver = {
548                 .name           = "mac53c94",
549                 .owner          = THIS_MODULE,
550                 .of_match_table = mac53c94_match,
551         },
552         .probe          = mac53c94_probe,
553         .remove         = mac53c94_remove,
554 };
555
556
557 static int __init init_mac53c94(void)
558 {
559         return macio_register_driver(&mac53c94_driver);
560 }
561
562 static void __exit exit_mac53c94(void)
563 {
564         return macio_unregister_driver(&mac53c94_driver);
565 }
566
567 module_init(init_mac53c94);
568 module_exit(exit_mac53c94);
569
570 MODULE_DESCRIPTION("PowerMac 53c94 SCSI driver");
571 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
572 MODULE_LICENSE("GPL");