1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic Macintosh NCR5380 driver
4 *
5 * Copyright 1998, Michael Schmitz <mschmitz@lbl.gov>
6 *
7 * Copyright 2019 Finn Thain
8 *
9 * derived in part from:
10 */
11/*
12 * Generic Generic NCR5380 driver
13 *
14 * Copyright 1995, Russell King
15 */
16
17#include <linux/delay.h>
18#include <linux/types.h>
19#include <linux/module.h>
20#include <linux/ioport.h>
21#include <linux/init.h>
22#include <linux/blkdev.h>
23#include <linux/interrupt.h>
24#include <linux/platform_device.h>
25
26#include <asm/hwtest.h>
27#include <asm/io.h>
28#include <asm/macintosh.h>
29#include <asm/macints.h>
30#include <asm/setup.h>
31
32#include <scsi/scsi_host.h>
33
34/* Definitions for the core NCR5380 driver. */
35
36#define NCR5380_implementation_fields   int pdma_residual
37
38#define NCR5380_read(reg)           in_8(hostdata->io + ((reg) << 4))
39#define NCR5380_write(reg, value)   out_8(hostdata->io + ((reg) << 4), value)
40
41#define NCR5380_dma_xfer_len            macscsi_dma_xfer_len
42#define NCR5380_dma_recv_setup          macscsi_pread
43#define NCR5380_dma_send_setup          macscsi_pwrite
44#define NCR5380_dma_residual            macscsi_dma_residual
45
46#define NCR5380_intr                    macscsi_intr
47#define NCR5380_queue_command           macscsi_queue_command
48#define NCR5380_abort                   macscsi_abort
49#define NCR5380_host_reset              macscsi_host_reset
50#define NCR5380_info                    macscsi_info
51
52#include "NCR5380.h"
53
54static int setup_can_queue = -1;
55module_param(setup_can_queue, int, 0);
56static int setup_cmd_per_lun = -1;
57module_param(setup_cmd_per_lun, int, 0);
58static int setup_sg_tablesize = -1;
59module_param(setup_sg_tablesize, int, 0);
60static int setup_use_pdma = 512;
61module_param(setup_use_pdma, int, 0);
62static int setup_hostid = -1;
63module_param(setup_hostid, int, 0);
64static int setup_toshiba_delay = -1;
65module_param(setup_toshiba_delay, int, 0);
66
67#ifndef MODULE
68static int __init mac_scsi_setup(char *str)
69{
70	int ints[8];
71
72	(void)get_options(str, ARRAY_SIZE(ints), ints);
73
74	if (ints[0] < 1) {
75		pr_err("Usage: mac5380=<can_queue>[,<cmd_per_lun>[,<sg_tablesize>[,<hostid>[,<use_tags>[,<use_pdma>[,<toshiba_delay>]]]]]]\n");
76		return 0;
77	}
78	if (ints[0] >= 1)
79		setup_can_queue = ints[1];
80	if (ints[0] >= 2)
81		setup_cmd_per_lun = ints[2];
82	if (ints[0] >= 3)
83		setup_sg_tablesize = ints[3];
84	if (ints[0] >= 4)
85		setup_hostid = ints[4];
86	/* ints[5] (use_tagged_queuing) is ignored */
87	if (ints[0] >= 6)
88		setup_use_pdma = ints[6];
89	if (ints[0] >= 7)
90		setup_toshiba_delay = ints[7];
91	return 1;
92}
93
94__setup("mac5380=", mac_scsi_setup);
95#endif /* !MODULE */
96
97/*
98 * According to "Inside Macintosh: Devices", Mac OS requires disk drivers to
99 * specify the number of bytes between the delays expected from a SCSI target.
100 * This allows the operating system to "prevent bus errors when a target fails
101 * to deliver the next byte within the processor bus error timeout period."
102 * Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets
103 * so bus errors are unavoidable.
104 *
105 * If a MOVE.B instruction faults, we assume that zero bytes were transferred
106 * and simply retry. That assumption probably depends on target behaviour but
107 * seems to hold up okay. The NOP provides synchronization: without it the
108 * fault can sometimes occur after the program counter has moved past the
109 * offending instruction. Post-increment addressing can't be used.
110 */
111
112#define MOVE_BYTE(operands) \
113	asm volatile ( \
114		"1:     moveb " operands "     \n" \
115		"11:    nop                    \n" \
116		"       addq #1,%0             \n" \
117		"       subq #1,%1             \n" \
118		"40:                           \n" \
119		"                              \n" \
120		".section .fixup,\"ax\"        \n" \
121		".even                         \n" \
122		"90:    movel #1, %2           \n" \
123		"       jra 40b                \n" \
124		".previous                     \n" \
125		"                              \n" \
126		".section __ex_table,\"a\"     \n" \
127		".align  4                     \n" \
128		".long   1b,90b                \n" \
129		".long  11b,90b                \n" \
130		".previous                     \n" \
131		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
132
133/*
134 * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because
135 * the residual byte count would be uncertain. In that situation the MOVE_WORD
136 * macro clears n in the fixup section to abort the transfer.
137 */
138
139#define MOVE_WORD(operands) \
140	asm volatile ( \
141		"1:     movew " operands "     \n" \
142		"11:    nop                    \n" \
143		"       subq #2,%1             \n" \
144		"40:                           \n" \
145		"                              \n" \
146		".section .fixup,\"ax\"        \n" \
147		".even                         \n" \
148		"90:    movel #0, %1           \n" \
149		"       movel #2, %2           \n" \
150		"       jra 40b                \n" \
151		".previous                     \n" \
152		"                              \n" \
153		".section __ex_table,\"a\"     \n" \
154		".align  4                     \n" \
155		".long   1b,90b                \n" \
156		".long  11b,90b                \n" \
157		".previous                     \n" \
158		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
159
160#define MOVE_16_WORDS(operands) \
161	asm volatile ( \
162		"1:     movew " operands "     \n" \
163		"2:     movew " operands "     \n" \
164		"3:     movew " operands "     \n" \
165		"4:     movew " operands "     \n" \
166		"5:     movew " operands "     \n" \
167		"6:     movew " operands "     \n" \
168		"7:     movew " operands "     \n" \
169		"8:     movew " operands "     \n" \
170		"9:     movew " operands "     \n" \
171		"10:    movew " operands "     \n" \
172		"11:    movew " operands "     \n" \
173		"12:    movew " operands "     \n" \
174		"13:    movew " operands "     \n" \
175		"14:    movew " operands "     \n" \
176		"15:    movew " operands "     \n" \
177		"16:    movew " operands "     \n" \
178		"17:    nop                    \n" \
179		"       subl  #32,%1           \n" \
180		"40:                           \n" \
181		"                              \n" \
182		".section .fixup,\"ax\"        \n" \
183		".even                         \n" \
184		"90:    movel #0, %1           \n" \
185		"       movel #2, %2           \n" \
186		"       jra 40b                \n" \
187		".previous                     \n" \
188		"                              \n" \
189		".section __ex_table,\"a\"     \n" \
190		".align  4                     \n" \
191		".long   1b,90b                \n" \
192		".long   2b,90b                \n" \
193		".long   3b,90b                \n" \
194		".long   4b,90b                \n" \
195		".long   5b,90b                \n" \
196		".long   6b,90b                \n" \
197		".long   7b,90b                \n" \
198		".long   8b,90b                \n" \
199		".long   9b,90b                \n" \
200		".long  10b,90b                \n" \
201		".long  11b,90b                \n" \
202		".long  12b,90b                \n" \
203		".long  13b,90b                \n" \
204		".long  14b,90b                \n" \
205		".long  15b,90b                \n" \
206		".long  16b,90b                \n" \
207		".long  17b,90b                \n" \
208		".previous                     \n" \
209		: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
210
211#define MAC_PDMA_DELAY		32
212
213static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
214{
215	unsigned char *addr = start;
216	int result = 0;
217
218	if (n >= 1) {
219		MOVE_BYTE("%3@,%0@");
220		if (result)
221			goto out;
222	}
223	if (n >= 1 && ((unsigned long)addr & 1)) {
224		MOVE_BYTE("%3@,%0@");
225		if (result)
226			goto out;
227	}
228	while (n >= 32)
229		MOVE_16_WORDS("%3@,%0@+");
230	while (n >= 2)
231		MOVE_WORD("%3@,%0@+");
232	if (result)
233		return start - addr; /* Negated to indicate uncertain length */
234	if (n == 1)
235		MOVE_BYTE("%3@,%0@");
236out:
237	return addr - start;
238}
239
240static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
241{
242	unsigned char *addr = start;
243	int result = 0;
244
245	if (n >= 1) {
246		MOVE_BYTE("%0@,%3@");
247		if (result)
248			goto out;
249	}
250	if (n >= 1 && ((unsigned long)addr & 1)) {
251		MOVE_BYTE("%0@,%3@");
252		if (result)
253			goto out;
254	}
255	while (n >= 32)
256		MOVE_16_WORDS("%0@+,%3@");
257	while (n >= 2)
258		MOVE_WORD("%0@+,%3@");
259	if (result)
260		return start - addr; /* Negated to indicate uncertain length */
261	if (n == 1)
262		MOVE_BYTE("%0@,%3@");
263out:
264	return addr - start;
265}
266
267/* The "SCSI DMA" chip on the IIfx implements this register. */
268#define CTRL_REG                0x8
269#define CTRL_INTERRUPTS_ENABLE  BIT(1)
270#define CTRL_HANDSHAKE_MODE     BIT(3)
271
272static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
273{
274	out_be32(hostdata->io + (CTRL_REG << 4), value);
275}
276
277static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
278                                unsigned char *dst, int len)
279{
280	u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
281	unsigned char *d = dst;
282	int result = 0;
283
284	hostdata->pdma_residual = len;
285
286	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
287	                              BASR_DRQ | BASR_PHASE_MATCH,
288	                              BASR_DRQ | BASR_PHASE_MATCH, 0)) {
289		int bytes;
290
291		if (macintosh_config->ident == MAC_MODEL_IIFX)
292			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
293			                         CTRL_INTERRUPTS_ENABLE);
294
295		bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512));
296
297		if (bytes > 0) {
298			d += bytes;
299			hostdata->pdma_residual -= bytes;
300		}
301
302		if (hostdata->pdma_residual == 0)
303			goto out;
304
305		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
306		                           BUS_AND_STATUS_REG, BASR_ACK,
307		                           BASR_ACK, 0) < 0)
308			scmd_printk(KERN_DEBUG, hostdata->connected,
309			            "%s: !REQ and !ACK\n", __func__);
310		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
311			goto out;
312
313		if (bytes == 0)
314			udelay(MAC_PDMA_DELAY);
315
316		if (bytes >= 0)
317			continue;
318
319		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
320		         "%s: bus error (%d/%d)\n", __func__, d - dst, len);
321		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
322		result = -1;
323		goto out;
324	}
325
326	scmd_printk(KERN_ERR, hostdata->connected,
327	            "%s: phase mismatch or !DRQ\n", __func__);
328	NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
329	result = -1;
330out:
331	if (macintosh_config->ident == MAC_MODEL_IIFX)
332		write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
333	return result;
334}
335
336static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
337                                 unsigned char *src, int len)
338{
339	unsigned char *s = src;
340	u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
341	int result = 0;
342
343	hostdata->pdma_residual = len;
344
345	while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
346	                              BASR_DRQ | BASR_PHASE_MATCH,
347	                              BASR_DRQ | BASR_PHASE_MATCH, 0)) {
348		int bytes;
349
350		if (macintosh_config->ident == MAC_MODEL_IIFX)
351			write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
352			                         CTRL_INTERRUPTS_ENABLE);
353
354		bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512));
355
356		if (bytes > 0) {
357			s += bytes;
358			hostdata->pdma_residual -= bytes;
359		}
360
361		if (hostdata->pdma_residual == 0) {
362			if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
363			                          TCR_LAST_BYTE_SENT,
364			                          TCR_LAST_BYTE_SENT,
365			                          0) < 0) {
366				scmd_printk(KERN_ERR, hostdata->connected,
367				            "%s: Last Byte Sent timeout\n", __func__);
368				result = -1;
369			}
370			goto out;
371		}
372
373		if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
374		                           BUS_AND_STATUS_REG, BASR_ACK,
375		                           BASR_ACK, 0) < 0)
376			scmd_printk(KERN_DEBUG, hostdata->connected,
377			            "%s: !REQ and !ACK\n", __func__);
378		if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
379			goto out;
380
381		if (bytes == 0)
382			udelay(MAC_PDMA_DELAY);
383
384		if (bytes >= 0)
385			continue;
386
387		dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
388		         "%s: bus error (%d/%d)\n", __func__, s - src, len);
389		NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
390		result = -1;
391		goto out;
392	}
393
394	scmd_printk(KERN_ERR, hostdata->connected,
395	            "%s: phase mismatch or !DRQ\n", __func__);
396	NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
397	result = -1;
398out:
399	if (macintosh_config->ident == MAC_MODEL_IIFX)
400		write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
401	return result;
402}
403
404static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
405                                struct scsi_cmnd *cmd)
406{
407	int resid = NCR5380_to_ncmd(cmd)->this_residual;
408
409	if (hostdata->flags & FLAG_NO_PSEUDO_DMA || resid < setup_use_pdma)
410		return 0;
411
412	return resid;
413}
414
415static int macscsi_dma_residual(struct NCR5380_hostdata *hostdata)
416{
417	return hostdata->pdma_residual;
418}
419
420#include "NCR5380.c"
421
422#define DRV_MODULE_NAME         "mac_scsi"
423#define PFX                     DRV_MODULE_NAME ": "
424
425static struct scsi_host_template mac_scsi_template = {
426	.module			= THIS_MODULE,
427	.proc_name		= DRV_MODULE_NAME,
428	.name			= "Macintosh NCR5380 SCSI",
429	.info			= macscsi_info,
430	.queuecommand		= macscsi_queue_command,
431	.eh_abort_handler	= macscsi_abort,
432	.eh_host_reset_handler	= macscsi_host_reset,
433	.can_queue		= 16,
434	.this_id		= 7,
435	.sg_tablesize		= 1,
436	.cmd_per_lun		= 2,
437	.dma_boundary		= PAGE_SIZE - 1,
438	.cmd_size		= sizeof(struct NCR5380_cmd),
439	.max_sectors		= 128,
440};
441
442static int __init mac_scsi_probe(struct platform_device *pdev)
443{
444	struct Scsi_Host *instance;
445	struct NCR5380_hostdata *hostdata;
446	int error;
447	int host_flags = 0;
448	struct resource *irq, *pio_mem, *pdma_mem = NULL;
449
450	pio_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
451	if (!pio_mem)
452		return -ENODEV;
453
454	pdma_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
455
456	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
457
458	if (!hwreg_present((unsigned char *)pio_mem->start +
459	                   (STATUS_REG << 4))) {
460		pr_info(PFX "no device detected at %pap\n", &pio_mem->start);
461		return -ENODEV;
462	}
463
464	if (setup_can_queue > 0)
465		mac_scsi_template.can_queue = setup_can_queue;
466	if (setup_cmd_per_lun > 0)
467		mac_scsi_template.cmd_per_lun = setup_cmd_per_lun;
468	if (setup_sg_tablesize > 0)
469		mac_scsi_template.sg_tablesize = setup_sg_tablesize;
470	if (setup_hostid >= 0)
471		mac_scsi_template.this_id = setup_hostid & 7;
472
473	instance = scsi_host_alloc(&mac_scsi_template,
474	                           sizeof(struct NCR5380_hostdata));
475	if (!instance)
476		return -ENOMEM;
477
478	if (irq)
479		instance->irq = irq->start;
480	else
481		instance->irq = NO_IRQ;
482
483	hostdata = shost_priv(instance);
484	hostdata->base = pio_mem->start;
485	hostdata->io = (u8 __iomem *)pio_mem->start;
486
487	if (pdma_mem && setup_use_pdma)
488		hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
489	else
490		host_flags |= FLAG_NO_PSEUDO_DMA;
491
492	host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
493
494	error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
495	if (error)
496		goto fail_init;
497
498	if (instance->irq != NO_IRQ) {
499		error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
500		                    "NCR5380", instance);
501		if (error)
502			goto fail_irq;
503	}
504
505	NCR5380_maybe_reset_bus(instance);
506
507	error = scsi_add_host(instance, NULL);
508	if (error)
509		goto fail_host;
510
511	platform_set_drvdata(pdev, instance);
512
513	scsi_scan_host(instance);
514	return 0;
515
516fail_host:
517	if (instance->irq != NO_IRQ)
518		free_irq(instance->irq, instance);
519fail_irq:
520	NCR5380_exit(instance);
521fail_init:
522	scsi_host_put(instance);
523	return error;
524}
525
526static void __exit mac_scsi_remove(struct platform_device *pdev)
527{
528	struct Scsi_Host *instance = platform_get_drvdata(pdev);
529
530	scsi_remove_host(instance);
531	if (instance->irq != NO_IRQ)
532		free_irq(instance->irq, instance);
533	NCR5380_exit(instance);
534	scsi_host_put(instance);
535}
536
537static struct platform_driver mac_scsi_driver = {
538	.remove_new = __exit_p(mac_scsi_remove),
539	.driver = {
540		.name	= DRV_MODULE_NAME,
541	},
542};
543
544module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);
545
546MODULE_ALIAS("platform:" DRV_MODULE_NAME);
547MODULE_LICENSE("GPL");
548