xref: /openbmc/linux/drivers/scsi/am53c974.c (revision 6d99a79c)
1 /*
2  * AMD am53c974 driver.
3  * Copyright (c) 2014 Hannes Reinecke, SUSE Linux GmbH
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/delay.h>
10 #include <linux/pci.h>
11 #include <linux/interrupt.h>
12 
13 #include <scsi/scsi_host.h>
14 
15 #include "esp_scsi.h"
16 
17 #define DRV_MODULE_NAME "am53c974"
18 #define DRV_MODULE_VERSION "1.00"
19 
20 static bool am53c974_debug;
21 static bool am53c974_fenab = true;
22 
23 #define esp_dma_log(f, a...)						\
24 	do {								\
25 		if (am53c974_debug)					\
26 			shost_printk(KERN_DEBUG, esp->host, f, ##a);	\
27 	} while (0)
28 
29 #define ESP_DMA_CMD 0x10
30 #define ESP_DMA_STC 0x11
31 #define ESP_DMA_SPA 0x12
32 #define ESP_DMA_WBC 0x13
33 #define ESP_DMA_WAC 0x14
34 #define ESP_DMA_STATUS 0x15
35 #define ESP_DMA_SMDLA 0x16
36 #define ESP_DMA_WMAC 0x17
37 
38 #define ESP_DMA_CMD_IDLE 0x00
39 #define ESP_DMA_CMD_BLAST 0x01
40 #define ESP_DMA_CMD_ABORT 0x02
41 #define ESP_DMA_CMD_START 0x03
42 #define ESP_DMA_CMD_MASK  0x03
43 #define ESP_DMA_CMD_DIAG 0x04
44 #define ESP_DMA_CMD_MDL 0x10
45 #define ESP_DMA_CMD_INTE_P 0x20
46 #define ESP_DMA_CMD_INTE_D 0x40
47 #define ESP_DMA_CMD_DIR 0x80
48 
49 #define ESP_DMA_STAT_PWDN 0x01
50 #define ESP_DMA_STAT_ERROR 0x02
51 #define ESP_DMA_STAT_ABORT 0x04
52 #define ESP_DMA_STAT_DONE 0x08
53 #define ESP_DMA_STAT_SCSIINT 0x10
54 #define ESP_DMA_STAT_BCMPLT 0x20
55 
56 /* EEPROM is accessed with 16-bit values */
57 #define DC390_EEPROM_READ 0x80
58 #define DC390_EEPROM_LEN 0x40
59 
60 /*
61  * DC390 EEPROM
62  *
63  * 8 * 4 bytes of per-device options
64  * followed by HBA specific options
65  */
66 
67 /* Per-device options */
68 #define DC390_EE_MODE1 0x00
69 #define DC390_EE_SPEED 0x01
70 
71 /* HBA-specific options */
72 #define DC390_EE_ADAPT_SCSI_ID 0x40
73 #define DC390_EE_MODE2 0x41
74 #define DC390_EE_DELAY 0x42
75 #define DC390_EE_TAG_CMD_NUM 0x43
76 
77 #define DC390_EE_MODE1_PARITY_CHK   0x01
78 #define DC390_EE_MODE1_SYNC_NEGO    0x02
79 #define DC390_EE_MODE1_EN_DISC      0x04
80 #define DC390_EE_MODE1_SEND_START   0x08
81 #define DC390_EE_MODE1_TCQ          0x10
82 
83 #define DC390_EE_MODE2_MORE_2DRV    0x01
84 #define DC390_EE_MODE2_GREATER_1G   0x02
85 #define DC390_EE_MODE2_RST_SCSI_BUS 0x04
86 #define DC390_EE_MODE2_ACTIVE_NEGATION 0x08
87 #define DC390_EE_MODE2_NO_SEEK      0x10
88 #define DC390_EE_MODE2_LUN_CHECK    0x20
89 
90 struct pci_esp_priv {
91 	struct esp *esp;
92 	u8 dma_status;
93 };
94 
95 static void pci_esp_dma_drain(struct esp *esp);
96 
97 static inline struct pci_esp_priv *pci_esp_get_priv(struct esp *esp)
98 {
99 	return dev_get_drvdata(esp->dev);
100 }
101 
102 static void pci_esp_write8(struct esp *esp, u8 val, unsigned long reg)
103 {
104 	iowrite8(val, esp->regs + (reg * 4UL));
105 }
106 
107 static u8 pci_esp_read8(struct esp *esp, unsigned long reg)
108 {
109 	return ioread8(esp->regs + (reg * 4UL));
110 }
111 
112 static void pci_esp_write32(struct esp *esp, u32 val, unsigned long reg)
113 {
114 	return iowrite32(val, esp->regs + (reg * 4UL));
115 }
116 
117 static int pci_esp_irq_pending(struct esp *esp)
118 {
119 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
120 
121 	pep->dma_status = pci_esp_read8(esp, ESP_DMA_STATUS);
122 	esp_dma_log("dma intr dreg[%02x]\n", pep->dma_status);
123 
124 	if (pep->dma_status & (ESP_DMA_STAT_ERROR |
125 			       ESP_DMA_STAT_ABORT |
126 			       ESP_DMA_STAT_DONE |
127 			       ESP_DMA_STAT_SCSIINT))
128 		return 1;
129 
130 	return 0;
131 }
132 
133 static void pci_esp_reset_dma(struct esp *esp)
134 {
135 	/* Nothing to do ? */
136 }
137 
138 static void pci_esp_dma_drain(struct esp *esp)
139 {
140 	u8 resid;
141 	int lim = 1000;
142 
143 
144 	if ((esp->sreg & ESP_STAT_PMASK) == ESP_DOP ||
145 	    (esp->sreg & ESP_STAT_PMASK) == ESP_DIP)
146 		/* Data-In or Data-Out, nothing to be done */
147 		return;
148 
149 	while (--lim > 0) {
150 		resid = pci_esp_read8(esp, ESP_FFLAGS) & ESP_FF_FBYTES;
151 		if (resid <= 1)
152 			break;
153 		cpu_relax();
154 	}
155 
156 	/*
157 	 * When there is a residual BCMPLT will never be set
158 	 * (obviously). But we still have to issue the BLAST
159 	 * command, otherwise the data will not being transferred.
160 	 * But we'll never know when the BLAST operation is
161 	 * finished. So check for some time and give up eventually.
162 	 */
163 	lim = 1000;
164 	pci_esp_write8(esp, ESP_DMA_CMD_DIR | ESP_DMA_CMD_BLAST, ESP_DMA_CMD);
165 	while (pci_esp_read8(esp, ESP_DMA_STATUS) & ESP_DMA_STAT_BCMPLT) {
166 		if (--lim == 0)
167 			break;
168 		cpu_relax();
169 	}
170 	pci_esp_write8(esp, ESP_DMA_CMD_DIR | ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
171 	esp_dma_log("DMA blast done (%d tries, %d bytes left)\n", lim, resid);
172 	/* BLAST residual handling is currently untested */
173 	if (WARN_ON_ONCE(resid == 1)) {
174 		struct esp_cmd_entry *ent = esp->active_cmd;
175 
176 		ent->flags |= ESP_CMD_FLAG_RESIDUAL;
177 	}
178 }
179 
180 static void pci_esp_dma_invalidate(struct esp *esp)
181 {
182 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
183 
184 	esp_dma_log("invalidate DMA\n");
185 
186 	pci_esp_write8(esp, ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
187 	pep->dma_status = 0;
188 }
189 
190 static int pci_esp_dma_error(struct esp *esp)
191 {
192 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
193 
194 	if (pep->dma_status & ESP_DMA_STAT_ERROR) {
195 		u8 dma_cmd = pci_esp_read8(esp, ESP_DMA_CMD);
196 
197 		if ((dma_cmd & ESP_DMA_CMD_MASK) == ESP_DMA_CMD_START)
198 			pci_esp_write8(esp, ESP_DMA_CMD_ABORT, ESP_DMA_CMD);
199 
200 		return 1;
201 	}
202 	if (pep->dma_status & ESP_DMA_STAT_ABORT) {
203 		pci_esp_write8(esp, ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
204 		pep->dma_status = pci_esp_read8(esp, ESP_DMA_CMD);
205 		return 1;
206 	}
207 	return 0;
208 }
209 
210 static void pci_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
211 				 u32 dma_count, int write, u8 cmd)
212 {
213 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
214 	u32 val = 0;
215 
216 	BUG_ON(!(cmd & ESP_CMD_DMA));
217 
218 	pep->dma_status = 0;
219 
220 	/* Set DMA engine to IDLE */
221 	if (write)
222 		/* DMA write direction logic is inverted */
223 		val |= ESP_DMA_CMD_DIR;
224 	pci_esp_write8(esp, ESP_DMA_CMD_IDLE | val, ESP_DMA_CMD);
225 
226 	pci_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
227 	pci_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
228 	if (esp->config2 & ESP_CONFIG2_FENAB)
229 		pci_esp_write8(esp, (esp_count >> 16) & 0xff, ESP_TCHI);
230 
231 	pci_esp_write32(esp, esp_count, ESP_DMA_STC);
232 	pci_esp_write32(esp, addr, ESP_DMA_SPA);
233 
234 	esp_dma_log("start dma addr[%x] count[%d:%d]\n",
235 		    addr, esp_count, dma_count);
236 
237 	scsi_esp_cmd(esp, cmd);
238 	/* Send DMA Start command */
239 	pci_esp_write8(esp, ESP_DMA_CMD_START | val, ESP_DMA_CMD);
240 }
241 
242 static u32 pci_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
243 {
244 	int dma_limit = 16;
245 	u32 base, end;
246 
247 	/*
248 	 * If CONFIG2_FENAB is set we can
249 	 * handle up to 24 bit addresses
250 	 */
251 	if (esp->config2 & ESP_CONFIG2_FENAB)
252 		dma_limit = 24;
253 
254 	if (dma_len > (1U << dma_limit))
255 		dma_len = (1U << dma_limit);
256 
257 	/*
258 	 * Prevent crossing a 24-bit address boundary.
259 	 */
260 	base = dma_addr & ((1U << 24) - 1U);
261 	end = base + dma_len;
262 	if (end > (1U << 24))
263 		end = (1U <<24);
264 	dma_len = end - base;
265 
266 	return dma_len;
267 }
268 
269 static const struct esp_driver_ops pci_esp_ops = {
270 	.esp_write8	=	pci_esp_write8,
271 	.esp_read8	=	pci_esp_read8,
272 	.irq_pending	=	pci_esp_irq_pending,
273 	.reset_dma	=	pci_esp_reset_dma,
274 	.dma_drain	=	pci_esp_dma_drain,
275 	.dma_invalidate	=	pci_esp_dma_invalidate,
276 	.send_dma_cmd	=	pci_esp_send_dma_cmd,
277 	.dma_error	=	pci_esp_dma_error,
278 	.dma_length_limit =	pci_esp_dma_length_limit,
279 };
280 
281 /*
282  * Read DC-390 eeprom
283  */
284 static void dc390_eeprom_prepare_read(struct pci_dev *pdev, u8 cmd)
285 {
286 	u8 carry_flag = 1, j = 0x80, bval;
287 	int i;
288 
289 	for (i = 0; i < 9; i++) {
290 		if (carry_flag) {
291 			pci_write_config_byte(pdev, 0x80, 0x40);
292 			bval = 0xc0;
293 		} else
294 			bval = 0x80;
295 
296 		udelay(160);
297 		pci_write_config_byte(pdev, 0x80, bval);
298 		udelay(160);
299 		pci_write_config_byte(pdev, 0x80, 0);
300 		udelay(160);
301 
302 		carry_flag = (cmd & j) ? 1 : 0;
303 		j >>= 1;
304 	}
305 }
306 
307 static u16 dc390_eeprom_get_data(struct pci_dev *pdev)
308 {
309 	int i;
310 	u16 wval = 0;
311 	u8 bval;
312 
313 	for (i = 0; i < 16; i++) {
314 		wval <<= 1;
315 
316 		pci_write_config_byte(pdev, 0x80, 0x80);
317 		udelay(160);
318 		pci_write_config_byte(pdev, 0x80, 0x40);
319 		udelay(160);
320 		pci_read_config_byte(pdev, 0x00, &bval);
321 
322 		if (bval == 0x22)
323 			wval |= 1;
324 	}
325 
326 	return wval;
327 }
328 
329 static void dc390_read_eeprom(struct pci_dev *pdev, u16 *ptr)
330 {
331 	u8 cmd = DC390_EEPROM_READ, i;
332 
333 	for (i = 0; i < DC390_EEPROM_LEN; i++) {
334 		pci_write_config_byte(pdev, 0xc0, 0);
335 		udelay(160);
336 
337 		dc390_eeprom_prepare_read(pdev, cmd++);
338 		*ptr++ = dc390_eeprom_get_data(pdev);
339 
340 		pci_write_config_byte(pdev, 0x80, 0);
341 		pci_write_config_byte(pdev, 0x80, 0);
342 		udelay(160);
343 	}
344 }
345 
346 static void dc390_check_eeprom(struct esp *esp)
347 {
348 	struct pci_dev *pdev = to_pci_dev(esp->dev);
349 	u8 EEbuf[128];
350 	u16 *ptr = (u16 *)EEbuf, wval = 0;
351 	int i;
352 
353 	dc390_read_eeprom(pdev, ptr);
354 
355 	for (i = 0; i < DC390_EEPROM_LEN; i++, ptr++)
356 		wval += *ptr;
357 
358 	/* no Tekram EEprom found */
359 	if (wval != 0x1234) {
360 		dev_printk(KERN_INFO, &pdev->dev,
361 			   "No valid Tekram EEprom found\n");
362 		return;
363 	}
364 	esp->scsi_id = EEbuf[DC390_EE_ADAPT_SCSI_ID];
365 	esp->num_tags = 2 << EEbuf[DC390_EE_TAG_CMD_NUM];
366 	if (EEbuf[DC390_EE_MODE2] & DC390_EE_MODE2_ACTIVE_NEGATION)
367 		esp->config4 |= ESP_CONFIG4_RADE | ESP_CONFIG4_RAE;
368 }
369 
370 static int pci_esp_probe_one(struct pci_dev *pdev,
371 			      const struct pci_device_id *id)
372 {
373 	struct scsi_host_template *hostt = &scsi_esp_template;
374 	int err = -ENODEV;
375 	struct Scsi_Host *shost;
376 	struct esp *esp;
377 	struct pci_esp_priv *pep;
378 
379 	if (pci_enable_device(pdev)) {
380 		dev_printk(KERN_INFO, &pdev->dev, "cannot enable device\n");
381 		return -ENODEV;
382 	}
383 
384 	if (dma_set_mask(&pdev->dev, DMA_BIT_MASK(32))) {
385 		dev_printk(KERN_INFO, &pdev->dev,
386 			   "failed to set 32bit DMA mask\n");
387 		goto fail_disable_device;
388 	}
389 
390 	shost = scsi_host_alloc(hostt, sizeof(struct esp));
391 	if (!shost) {
392 		dev_printk(KERN_INFO, &pdev->dev,
393 			   "failed to allocate scsi host\n");
394 		err = -ENOMEM;
395 		goto fail_disable_device;
396 	}
397 
398 	pep = kzalloc(sizeof(struct pci_esp_priv), GFP_KERNEL);
399 	if (!pep) {
400 		dev_printk(KERN_INFO, &pdev->dev,
401 			   "failed to allocate esp_priv\n");
402 		err = -ENOMEM;
403 		goto fail_host_alloc;
404 	}
405 
406 	esp = shost_priv(shost);
407 	esp->host = shost;
408 	esp->dev = &pdev->dev;
409 	esp->ops = &pci_esp_ops;
410 	/*
411 	 * The am53c974 HBA has a design flaw of generating
412 	 * spurious DMA completion interrupts when using
413 	 * DMA for command submission.
414 	 */
415 	esp->flags |= ESP_FLAG_USE_FIFO;
416 	/*
417 	 * Enable CONFIG2_FENAB to allow for large DMA transfers
418 	 */
419 	if (am53c974_fenab)
420 		esp->config2 |= ESP_CONFIG2_FENAB;
421 
422 	pep->esp = esp;
423 
424 	if (pci_request_regions(pdev, DRV_MODULE_NAME)) {
425 		dev_printk(KERN_ERR, &pdev->dev,
426 			   "pci memory selection failed\n");
427 		goto fail_priv_alloc;
428 	}
429 
430 	esp->regs = pci_iomap(pdev, 0, pci_resource_len(pdev, 0));
431 	if (!esp->regs) {
432 		dev_printk(KERN_ERR, &pdev->dev, "pci I/O map failed\n");
433 		err = -EINVAL;
434 		goto fail_release_regions;
435 	}
436 	esp->dma_regs = esp->regs;
437 
438 	pci_set_master(pdev);
439 
440 	esp->command_block = dma_alloc_coherent(&pdev->dev, 16,
441 			&esp->command_block_dma, GFP_KERNEL);
442 	if (!esp->command_block) {
443 		dev_printk(KERN_ERR, &pdev->dev,
444 			   "failed to allocate command block\n");
445 		err = -ENOMEM;
446 		goto fail_unmap_regs;
447 	}
448 
449 	pci_set_drvdata(pdev, pep);
450 
451 	err = request_irq(pdev->irq, scsi_esp_intr, IRQF_SHARED,
452 			  DRV_MODULE_NAME, esp);
453 	if (err < 0) {
454 		dev_printk(KERN_ERR, &pdev->dev, "failed to register IRQ\n");
455 		goto fail_unmap_command_block;
456 	}
457 
458 	esp->scsi_id = 7;
459 	dc390_check_eeprom(esp);
460 
461 	shost->this_id = esp->scsi_id;
462 	shost->max_id = 8;
463 	shost->irq = pdev->irq;
464 	shost->io_port = pci_resource_start(pdev, 0);
465 	shost->n_io_port = pci_resource_len(pdev, 0);
466 	shost->unique_id = shost->io_port;
467 	esp->scsi_id_mask = (1 << esp->scsi_id);
468 	/* Assume 40MHz clock */
469 	esp->cfreq = 40000000;
470 
471 	err = scsi_esp_register(esp);
472 	if (err)
473 		goto fail_free_irq;
474 
475 	return 0;
476 
477 fail_free_irq:
478 	free_irq(pdev->irq, esp);
479 fail_unmap_command_block:
480 	pci_set_drvdata(pdev, NULL);
481 	dma_free_coherent(&pdev->dev, 16, esp->command_block,
482 			  esp->command_block_dma);
483 fail_unmap_regs:
484 	pci_iounmap(pdev, esp->regs);
485 fail_release_regions:
486 	pci_release_regions(pdev);
487 fail_priv_alloc:
488 	kfree(pep);
489 fail_host_alloc:
490 	scsi_host_put(shost);
491 fail_disable_device:
492 	pci_disable_device(pdev);
493 
494 	return err;
495 }
496 
497 static void pci_esp_remove_one(struct pci_dev *pdev)
498 {
499 	struct pci_esp_priv *pep = pci_get_drvdata(pdev);
500 	struct esp *esp = pep->esp;
501 
502 	scsi_esp_unregister(esp);
503 	free_irq(pdev->irq, esp);
504 	pci_set_drvdata(pdev, NULL);
505 	dma_free_coherent(&pdev->dev, 16, esp->command_block,
506 			  esp->command_block_dma);
507 	pci_iounmap(pdev, esp->regs);
508 	pci_release_regions(pdev);
509 	pci_disable_device(pdev);
510 	kfree(pep);
511 
512 	scsi_host_put(esp->host);
513 }
514 
515 static struct pci_device_id am53c974_pci_tbl[] = {
516 	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_SCSI,
517 		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
518 	{ }
519 };
520 MODULE_DEVICE_TABLE(pci, am53c974_pci_tbl);
521 
522 static struct pci_driver am53c974_driver = {
523 	.name           = DRV_MODULE_NAME,
524 	.id_table       = am53c974_pci_tbl,
525 	.probe          = pci_esp_probe_one,
526 	.remove         = pci_esp_remove_one,
527 };
528 
529 module_pci_driver(am53c974_driver);
530 
531 MODULE_DESCRIPTION("AM53C974 SCSI driver");
532 MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
533 MODULE_LICENSE("GPL");
534 MODULE_VERSION(DRV_MODULE_VERSION);
535 MODULE_ALIAS("tmscsim");
536 
537 module_param(am53c974_debug, bool, 0644);
538 MODULE_PARM_DESC(am53c974_debug, "Enable debugging");
539 
540 module_param(am53c974_fenab, bool, 0444);
541 MODULE_PARM_DESC(am53c974_fenab, "Enable 24-bit DMA transfer sizes");
542