xref: /openbmc/linux/drivers/scsi/am53c974.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AMD am53c974 driver.
4  * Copyright (c) 2014 Hannes Reinecke, SUSE Linux GmbH
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/delay.h>
11 #include <linux/pci.h>
12 #include <linux/interrupt.h>
13 
14 #include <scsi/scsi_host.h>
15 
16 #include "esp_scsi.h"
17 
18 #define DRV_MODULE_NAME "am53c974"
19 #define DRV_MODULE_VERSION "1.00"
20 
21 static bool am53c974_debug;
22 static bool am53c974_fenab = true;
23 
24 #define esp_dma_log(f, a...)						\
25 	do {								\
26 		if (am53c974_debug)					\
27 			shost_printk(KERN_DEBUG, esp->host, f, ##a);	\
28 	} while (0)
29 
30 #define ESP_DMA_CMD 0x10
31 #define ESP_DMA_STC 0x11
32 #define ESP_DMA_SPA 0x12
33 #define ESP_DMA_WBC 0x13
34 #define ESP_DMA_WAC 0x14
35 #define ESP_DMA_STATUS 0x15
36 #define ESP_DMA_SMDLA 0x16
37 #define ESP_DMA_WMAC 0x17
38 
39 #define ESP_DMA_CMD_IDLE 0x00
40 #define ESP_DMA_CMD_BLAST 0x01
41 #define ESP_DMA_CMD_ABORT 0x02
42 #define ESP_DMA_CMD_START 0x03
43 #define ESP_DMA_CMD_MASK  0x03
44 #define ESP_DMA_CMD_DIAG 0x04
45 #define ESP_DMA_CMD_MDL 0x10
46 #define ESP_DMA_CMD_INTE_P 0x20
47 #define ESP_DMA_CMD_INTE_D 0x40
48 #define ESP_DMA_CMD_DIR 0x80
49 
50 #define ESP_DMA_STAT_PWDN 0x01
51 #define ESP_DMA_STAT_ERROR 0x02
52 #define ESP_DMA_STAT_ABORT 0x04
53 #define ESP_DMA_STAT_DONE 0x08
54 #define ESP_DMA_STAT_SCSIINT 0x10
55 #define ESP_DMA_STAT_BCMPLT 0x20
56 
57 /* EEPROM is accessed with 16-bit values */
58 #define DC390_EEPROM_READ 0x80
59 #define DC390_EEPROM_LEN 0x40
60 
61 /*
62  * DC390 EEPROM
63  *
64  * 8 * 4 bytes of per-device options
65  * followed by HBA specific options
66  */
67 
68 /* Per-device options */
69 #define DC390_EE_MODE1 0x00
70 #define DC390_EE_SPEED 0x01
71 
72 /* HBA-specific options */
73 #define DC390_EE_ADAPT_SCSI_ID 0x40
74 #define DC390_EE_MODE2 0x41
75 #define DC390_EE_DELAY 0x42
76 #define DC390_EE_TAG_CMD_NUM 0x43
77 
78 #define DC390_EE_MODE1_PARITY_CHK   0x01
79 #define DC390_EE_MODE1_SYNC_NEGO    0x02
80 #define DC390_EE_MODE1_EN_DISC      0x04
81 #define DC390_EE_MODE1_SEND_START   0x08
82 #define DC390_EE_MODE1_TCQ          0x10
83 
84 #define DC390_EE_MODE2_MORE_2DRV    0x01
85 #define DC390_EE_MODE2_GREATER_1G   0x02
86 #define DC390_EE_MODE2_RST_SCSI_BUS 0x04
87 #define DC390_EE_MODE2_ACTIVE_NEGATION 0x08
88 #define DC390_EE_MODE2_NO_SEEK      0x10
89 #define DC390_EE_MODE2_LUN_CHECK    0x20
90 
91 struct pci_esp_priv {
92 	struct esp *esp;
93 	u8 dma_status;
94 };
95 
96 static void pci_esp_dma_drain(struct esp *esp);
97 
98 static inline struct pci_esp_priv *pci_esp_get_priv(struct esp *esp)
99 {
100 	return dev_get_drvdata(esp->dev);
101 }
102 
103 static void pci_esp_write8(struct esp *esp, u8 val, unsigned long reg)
104 {
105 	iowrite8(val, esp->regs + (reg * 4UL));
106 }
107 
108 static u8 pci_esp_read8(struct esp *esp, unsigned long reg)
109 {
110 	return ioread8(esp->regs + (reg * 4UL));
111 }
112 
113 static void pci_esp_write32(struct esp *esp, u32 val, unsigned long reg)
114 {
115 	return iowrite32(val, esp->regs + (reg * 4UL));
116 }
117 
118 static int pci_esp_irq_pending(struct esp *esp)
119 {
120 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
121 
122 	pep->dma_status = pci_esp_read8(esp, ESP_DMA_STATUS);
123 	esp_dma_log("dma intr dreg[%02x]\n", pep->dma_status);
124 
125 	if (pep->dma_status & (ESP_DMA_STAT_ERROR |
126 			       ESP_DMA_STAT_ABORT |
127 			       ESP_DMA_STAT_DONE |
128 			       ESP_DMA_STAT_SCSIINT))
129 		return 1;
130 
131 	return 0;
132 }
133 
134 static void pci_esp_reset_dma(struct esp *esp)
135 {
136 	/* Nothing to do ? */
137 }
138 
139 static void pci_esp_dma_drain(struct esp *esp)
140 {
141 	u8 resid;
142 	int lim = 1000;
143 
144 
145 	if ((esp->sreg & ESP_STAT_PMASK) == ESP_DOP ||
146 	    (esp->sreg & ESP_STAT_PMASK) == ESP_DIP)
147 		/* Data-In or Data-Out, nothing to be done */
148 		return;
149 
150 	while (--lim > 0) {
151 		resid = pci_esp_read8(esp, ESP_FFLAGS) & ESP_FF_FBYTES;
152 		if (resid <= 1)
153 			break;
154 		cpu_relax();
155 	}
156 
157 	/*
158 	 * When there is a residual BCMPLT will never be set
159 	 * (obviously). But we still have to issue the BLAST
160 	 * command, otherwise the data will not being transferred.
161 	 * But we'll never know when the BLAST operation is
162 	 * finished. So check for some time and give up eventually.
163 	 */
164 	lim = 1000;
165 	pci_esp_write8(esp, ESP_DMA_CMD_DIR | ESP_DMA_CMD_BLAST, ESP_DMA_CMD);
166 	while (pci_esp_read8(esp, ESP_DMA_STATUS) & ESP_DMA_STAT_BCMPLT) {
167 		if (--lim == 0)
168 			break;
169 		cpu_relax();
170 	}
171 	pci_esp_write8(esp, ESP_DMA_CMD_DIR | ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
172 	esp_dma_log("DMA blast done (%d tries, %d bytes left)\n", lim, resid);
173 	/* BLAST residual handling is currently untested */
174 	if (WARN_ON_ONCE(resid == 1)) {
175 		struct esp_cmd_entry *ent = esp->active_cmd;
176 
177 		ent->flags |= ESP_CMD_FLAG_RESIDUAL;
178 	}
179 }
180 
181 static void pci_esp_dma_invalidate(struct esp *esp)
182 {
183 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
184 
185 	esp_dma_log("invalidate DMA\n");
186 
187 	pci_esp_write8(esp, ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
188 	pep->dma_status = 0;
189 }
190 
191 static int pci_esp_dma_error(struct esp *esp)
192 {
193 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
194 
195 	if (pep->dma_status & ESP_DMA_STAT_ERROR) {
196 		u8 dma_cmd = pci_esp_read8(esp, ESP_DMA_CMD);
197 
198 		if ((dma_cmd & ESP_DMA_CMD_MASK) == ESP_DMA_CMD_START)
199 			pci_esp_write8(esp, ESP_DMA_CMD_ABORT, ESP_DMA_CMD);
200 
201 		return 1;
202 	}
203 	if (pep->dma_status & ESP_DMA_STAT_ABORT) {
204 		pci_esp_write8(esp, ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
205 		pep->dma_status = pci_esp_read8(esp, ESP_DMA_CMD);
206 		return 1;
207 	}
208 	return 0;
209 }
210 
211 static void pci_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
212 				 u32 dma_count, int write, u8 cmd)
213 {
214 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
215 	u32 val = 0;
216 
217 	BUG_ON(!(cmd & ESP_CMD_DMA));
218 
219 	pep->dma_status = 0;
220 
221 	/* Set DMA engine to IDLE */
222 	if (write)
223 		/* DMA write direction logic is inverted */
224 		val |= ESP_DMA_CMD_DIR;
225 	pci_esp_write8(esp, ESP_DMA_CMD_IDLE | val, ESP_DMA_CMD);
226 
227 	pci_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
228 	pci_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
229 	if (esp->config2 & ESP_CONFIG2_FENAB)
230 		pci_esp_write8(esp, (esp_count >> 16) & 0xff, ESP_TCHI);
231 
232 	pci_esp_write32(esp, esp_count, ESP_DMA_STC);
233 	pci_esp_write32(esp, addr, ESP_DMA_SPA);
234 
235 	esp_dma_log("start dma addr[%x] count[%d:%d]\n",
236 		    addr, esp_count, dma_count);
237 
238 	scsi_esp_cmd(esp, cmd);
239 	/* Send DMA Start command */
240 	pci_esp_write8(esp, ESP_DMA_CMD_START | val, ESP_DMA_CMD);
241 }
242 
243 static u32 pci_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
244 {
245 	int dma_limit = 16;
246 	u32 base, end;
247 
248 	/*
249 	 * If CONFIG2_FENAB is set we can
250 	 * handle up to 24 bit addresses
251 	 */
252 	if (esp->config2 & ESP_CONFIG2_FENAB)
253 		dma_limit = 24;
254 
255 	if (dma_len > (1U << dma_limit))
256 		dma_len = (1U << dma_limit);
257 
258 	/*
259 	 * Prevent crossing a 24-bit address boundary.
260 	 */
261 	base = dma_addr & ((1U << 24) - 1U);
262 	end = base + dma_len;
263 	if (end > (1U << 24))
264 		end = (1U <<24);
265 	dma_len = end - base;
266 
267 	return dma_len;
268 }
269 
270 static const struct esp_driver_ops pci_esp_ops = {
271 	.esp_write8	=	pci_esp_write8,
272 	.esp_read8	=	pci_esp_read8,
273 	.irq_pending	=	pci_esp_irq_pending,
274 	.reset_dma	=	pci_esp_reset_dma,
275 	.dma_drain	=	pci_esp_dma_drain,
276 	.dma_invalidate	=	pci_esp_dma_invalidate,
277 	.send_dma_cmd	=	pci_esp_send_dma_cmd,
278 	.dma_error	=	pci_esp_dma_error,
279 	.dma_length_limit =	pci_esp_dma_length_limit,
280 };
281 
282 /*
283  * Read DC-390 eeprom
284  */
285 static void dc390_eeprom_prepare_read(struct pci_dev *pdev, u8 cmd)
286 {
287 	u8 carry_flag = 1, j = 0x80, bval;
288 	int i;
289 
290 	for (i = 0; i < 9; i++) {
291 		if (carry_flag) {
292 			pci_write_config_byte(pdev, 0x80, 0x40);
293 			bval = 0xc0;
294 		} else
295 			bval = 0x80;
296 
297 		udelay(160);
298 		pci_write_config_byte(pdev, 0x80, bval);
299 		udelay(160);
300 		pci_write_config_byte(pdev, 0x80, 0);
301 		udelay(160);
302 
303 		carry_flag = (cmd & j) ? 1 : 0;
304 		j >>= 1;
305 	}
306 }
307 
308 static u16 dc390_eeprom_get_data(struct pci_dev *pdev)
309 {
310 	int i;
311 	u16 wval = 0;
312 	u8 bval;
313 
314 	for (i = 0; i < 16; i++) {
315 		wval <<= 1;
316 
317 		pci_write_config_byte(pdev, 0x80, 0x80);
318 		udelay(160);
319 		pci_write_config_byte(pdev, 0x80, 0x40);
320 		udelay(160);
321 		pci_read_config_byte(pdev, 0x00, &bval);
322 
323 		if (bval == 0x22)
324 			wval |= 1;
325 	}
326 
327 	return wval;
328 }
329 
330 static void dc390_read_eeprom(struct pci_dev *pdev, u16 *ptr)
331 {
332 	u8 cmd = DC390_EEPROM_READ, i;
333 
334 	for (i = 0; i < DC390_EEPROM_LEN; i++) {
335 		pci_write_config_byte(pdev, 0xc0, 0);
336 		udelay(160);
337 
338 		dc390_eeprom_prepare_read(pdev, cmd++);
339 		*ptr++ = dc390_eeprom_get_data(pdev);
340 
341 		pci_write_config_byte(pdev, 0x80, 0);
342 		pci_write_config_byte(pdev, 0x80, 0);
343 		udelay(160);
344 	}
345 }
346 
347 static void dc390_check_eeprom(struct esp *esp)
348 {
349 	struct pci_dev *pdev = to_pci_dev(esp->dev);
350 	u8 EEbuf[128];
351 	u16 *ptr = (u16 *)EEbuf, wval = 0;
352 	int i;
353 
354 	dc390_read_eeprom(pdev, ptr);
355 
356 	for (i = 0; i < DC390_EEPROM_LEN; i++, ptr++)
357 		wval += *ptr;
358 
359 	/* no Tekram EEprom found */
360 	if (wval != 0x1234) {
361 		dev_printk(KERN_INFO, &pdev->dev,
362 			   "No valid Tekram EEprom found\n");
363 		return;
364 	}
365 	esp->scsi_id = EEbuf[DC390_EE_ADAPT_SCSI_ID];
366 	esp->num_tags = 2 << EEbuf[DC390_EE_TAG_CMD_NUM];
367 	if (EEbuf[DC390_EE_MODE2] & DC390_EE_MODE2_ACTIVE_NEGATION)
368 		esp->config4 |= ESP_CONFIG4_RADE | ESP_CONFIG4_RAE;
369 }
370 
371 static int pci_esp_probe_one(struct pci_dev *pdev,
372 			      const struct pci_device_id *id)
373 {
374 	struct scsi_host_template *hostt = &scsi_esp_template;
375 	int err = -ENODEV;
376 	struct Scsi_Host *shost;
377 	struct esp *esp;
378 	struct pci_esp_priv *pep;
379 
380 	if (pci_enable_device(pdev)) {
381 		dev_printk(KERN_INFO, &pdev->dev, "cannot enable device\n");
382 		return -ENODEV;
383 	}
384 
385 	if (dma_set_mask(&pdev->dev, DMA_BIT_MASK(32))) {
386 		dev_printk(KERN_INFO, &pdev->dev,
387 			   "failed to set 32bit DMA mask\n");
388 		goto fail_disable_device;
389 	}
390 
391 	shost = scsi_host_alloc(hostt, sizeof(struct esp));
392 	if (!shost) {
393 		dev_printk(KERN_INFO, &pdev->dev,
394 			   "failed to allocate scsi host\n");
395 		err = -ENOMEM;
396 		goto fail_disable_device;
397 	}
398 
399 	pep = kzalloc(sizeof(struct pci_esp_priv), GFP_KERNEL);
400 	if (!pep) {
401 		dev_printk(KERN_INFO, &pdev->dev,
402 			   "failed to allocate esp_priv\n");
403 		err = -ENOMEM;
404 		goto fail_host_alloc;
405 	}
406 
407 	esp = shost_priv(shost);
408 	esp->host = shost;
409 	esp->dev = &pdev->dev;
410 	esp->ops = &pci_esp_ops;
411 	/*
412 	 * The am53c974 HBA has a design flaw of generating
413 	 * spurious DMA completion interrupts when using
414 	 * DMA for command submission.
415 	 */
416 	esp->flags |= ESP_FLAG_USE_FIFO;
417 	/*
418 	 * Enable CONFIG2_FENAB to allow for large DMA transfers
419 	 */
420 	if (am53c974_fenab)
421 		esp->config2 |= ESP_CONFIG2_FENAB;
422 
423 	pep->esp = esp;
424 
425 	if (pci_request_regions(pdev, DRV_MODULE_NAME)) {
426 		dev_printk(KERN_ERR, &pdev->dev,
427 			   "pci memory selection failed\n");
428 		goto fail_priv_alloc;
429 	}
430 
431 	esp->regs = pci_iomap(pdev, 0, pci_resource_len(pdev, 0));
432 	if (!esp->regs) {
433 		dev_printk(KERN_ERR, &pdev->dev, "pci I/O map failed\n");
434 		err = -EINVAL;
435 		goto fail_release_regions;
436 	}
437 	esp->dma_regs = esp->regs;
438 
439 	pci_set_master(pdev);
440 
441 	esp->command_block = dma_alloc_coherent(&pdev->dev, 16,
442 			&esp->command_block_dma, GFP_KERNEL);
443 	if (!esp->command_block) {
444 		dev_printk(KERN_ERR, &pdev->dev,
445 			   "failed to allocate command block\n");
446 		err = -ENOMEM;
447 		goto fail_unmap_regs;
448 	}
449 
450 	pci_set_drvdata(pdev, pep);
451 
452 	err = request_irq(pdev->irq, scsi_esp_intr, IRQF_SHARED,
453 			  DRV_MODULE_NAME, esp);
454 	if (err < 0) {
455 		dev_printk(KERN_ERR, &pdev->dev, "failed to register IRQ\n");
456 		goto fail_unmap_command_block;
457 	}
458 
459 	esp->scsi_id = 7;
460 	dc390_check_eeprom(esp);
461 
462 	shost->this_id = esp->scsi_id;
463 	shost->max_id = 8;
464 	shost->irq = pdev->irq;
465 	shost->io_port = pci_resource_start(pdev, 0);
466 	shost->n_io_port = pci_resource_len(pdev, 0);
467 	shost->unique_id = shost->io_port;
468 	esp->scsi_id_mask = (1 << esp->scsi_id);
469 	/* Assume 40MHz clock */
470 	esp->cfreq = 40000000;
471 
472 	err = scsi_esp_register(esp);
473 	if (err)
474 		goto fail_free_irq;
475 
476 	return 0;
477 
478 fail_free_irq:
479 	free_irq(pdev->irq, esp);
480 fail_unmap_command_block:
481 	pci_set_drvdata(pdev, NULL);
482 	dma_free_coherent(&pdev->dev, 16, esp->command_block,
483 			  esp->command_block_dma);
484 fail_unmap_regs:
485 	pci_iounmap(pdev, esp->regs);
486 fail_release_regions:
487 	pci_release_regions(pdev);
488 fail_priv_alloc:
489 	kfree(pep);
490 fail_host_alloc:
491 	scsi_host_put(shost);
492 fail_disable_device:
493 	pci_disable_device(pdev);
494 
495 	return err;
496 }
497 
498 static void pci_esp_remove_one(struct pci_dev *pdev)
499 {
500 	struct pci_esp_priv *pep = pci_get_drvdata(pdev);
501 	struct esp *esp = pep->esp;
502 
503 	scsi_esp_unregister(esp);
504 	free_irq(pdev->irq, esp);
505 	pci_set_drvdata(pdev, NULL);
506 	dma_free_coherent(&pdev->dev, 16, esp->command_block,
507 			  esp->command_block_dma);
508 	pci_iounmap(pdev, esp->regs);
509 	pci_release_regions(pdev);
510 	pci_disable_device(pdev);
511 	kfree(pep);
512 
513 	scsi_host_put(esp->host);
514 }
515 
516 static struct pci_device_id am53c974_pci_tbl[] = {
517 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_SCSI,
518 		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
519 	{ }
520 };
521 MODULE_DEVICE_TABLE(pci, am53c974_pci_tbl);
522 
523 static struct pci_driver am53c974_driver = {
524 	.name           = DRV_MODULE_NAME,
525 	.id_table       = am53c974_pci_tbl,
526 	.probe          = pci_esp_probe_one,
527 	.remove         = pci_esp_remove_one,
528 };
529 
530 module_pci_driver(am53c974_driver);
531 
532 MODULE_DESCRIPTION("AM53C974 SCSI driver");
533 MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
534 MODULE_LICENSE("GPL");
535 MODULE_VERSION(DRV_MODULE_VERSION);
536 MODULE_ALIAS("tmscsim");
537 
538 module_param(am53c974_debug, bool, 0644);
539 MODULE_PARM_DESC(am53c974_debug, "Enable debugging");
540 
541 module_param(am53c974_fenab, bool, 0444);
542 MODULE_PARM_DESC(am53c974_fenab, "Enable 24-bit DMA transfer sizes");
543