xref: /openbmc/linux/drivers/ata/sata_dwc_460ex.c (revision 8dde5715)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * drivers/ata/sata_dwc_460ex.c
4  *
5  * Synopsys DesignWare Cores (DWC) SATA host driver
6  *
7  * Author: Mark Miesfeld <mmiesfeld@amcc.com>
8  *
9  * Ported from 2.6.19.2 to 2.6.25/26 by Stefan Roese <sr@denx.de>
10  * Copyright 2008 DENX Software Engineering
11  *
12  * Based on versions provided by AMCC and Synopsys which are:
13  *          Copyright 2006 Applied Micro Circuits Corporation
14  *          COPYRIGHT (C) 2005  SYNOPSYS, INC.  ALL RIGHTS RESERVED
15  */
16 
17 #ifdef CONFIG_SATA_DWC_DEBUG
18 #define DEBUG
19 #endif
20 
21 #ifdef CONFIG_SATA_DWC_VDEBUG
22 #define VERBOSE_DEBUG
23 #define DEBUG_NCQ
24 #endif
25 
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/device.h>
29 #include <linux/dmaengine.h>
30 #include <linux/of_address.h>
31 #include <linux/of_irq.h>
32 #include <linux/of_platform.h>
33 #include <linux/platform_device.h>
34 #include <linux/phy/phy.h>
35 #include <linux/libata.h>
36 #include <linux/slab.h>
37 
38 #include "libata.h"
39 
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi_cmnd.h>
42 
43 /* These two are defined in "libata.h" */
44 #undef	DRV_NAME
45 #undef	DRV_VERSION
46 
47 #define DRV_NAME        "sata-dwc"
48 #define DRV_VERSION     "1.3"
49 
50 #define sata_dwc_writel(a, v)	writel_relaxed(v, a)
51 #define sata_dwc_readl(a)	readl_relaxed(a)
52 
53 #ifndef NO_IRQ
54 #define NO_IRQ		0
55 #endif
56 
57 #define AHB_DMA_BRST_DFLT	64	/* 16 data items burst length */
58 
59 enum {
60 	SATA_DWC_MAX_PORTS = 1,
61 
62 	SATA_DWC_SCR_OFFSET = 0x24,
63 	SATA_DWC_REG_OFFSET = 0x64,
64 };
65 
66 /* DWC SATA Registers */
67 struct sata_dwc_regs {
68 	u32 fptagr;		/* 1st party DMA tag */
69 	u32 fpbor;		/* 1st party DMA buffer offset */
70 	u32 fptcr;		/* 1st party DMA Xfr count */
71 	u32 dmacr;		/* DMA Control */
72 	u32 dbtsr;		/* DMA Burst Transac size */
73 	u32 intpr;		/* Interrupt Pending */
74 	u32 intmr;		/* Interrupt Mask */
75 	u32 errmr;		/* Error Mask */
76 	u32 llcr;		/* Link Layer Control */
77 	u32 phycr;		/* PHY Control */
78 	u32 physr;		/* PHY Status */
79 	u32 rxbistpd;		/* Recvd BIST pattern def register */
80 	u32 rxbistpd1;		/* Recvd BIST data dword1 */
81 	u32 rxbistpd2;		/* Recvd BIST pattern data dword2 */
82 	u32 txbistpd;		/* Trans BIST pattern def register */
83 	u32 txbistpd1;		/* Trans BIST data dword1 */
84 	u32 txbistpd2;		/* Trans BIST data dword2 */
85 	u32 bistcr;		/* BIST Control Register */
86 	u32 bistfctr;		/* BIST FIS Count Register */
87 	u32 bistsr;		/* BIST Status Register */
88 	u32 bistdecr;		/* BIST Dword Error count register */
89 	u32 res[15];		/* Reserved locations */
90 	u32 testr;		/* Test Register */
91 	u32 versionr;		/* Version Register */
92 	u32 idr;		/* ID Register */
93 	u32 unimpl[192];	/* Unimplemented */
94 	u32 dmadr[256];		/* FIFO Locations in DMA Mode */
95 };
96 
97 enum {
98 	SCR_SCONTROL_DET_ENABLE	=	0x00000001,
99 	SCR_SSTATUS_DET_PRESENT	=	0x00000001,
100 	SCR_SERROR_DIAG_X	=	0x04000000,
101 /* DWC SATA Register Operations */
102 	SATA_DWC_TXFIFO_DEPTH	=	0x01FF,
103 	SATA_DWC_RXFIFO_DEPTH	=	0x01FF,
104 	SATA_DWC_DMACR_TMOD_TXCHEN =	0x00000004,
105 	SATA_DWC_DMACR_TXCHEN	= (0x00000001 | SATA_DWC_DMACR_TMOD_TXCHEN),
106 	SATA_DWC_DMACR_RXCHEN	= (0x00000002 | SATA_DWC_DMACR_TMOD_TXCHEN),
107 	SATA_DWC_DMACR_TXRXCH_CLEAR =	SATA_DWC_DMACR_TMOD_TXCHEN,
108 	SATA_DWC_INTPR_DMAT	=	0x00000001,
109 	SATA_DWC_INTPR_NEWFP	=	0x00000002,
110 	SATA_DWC_INTPR_PMABRT	=	0x00000004,
111 	SATA_DWC_INTPR_ERR	=	0x00000008,
112 	SATA_DWC_INTPR_NEWBIST	=	0x00000010,
113 	SATA_DWC_INTPR_IPF	=	0x10000000,
114 	SATA_DWC_INTMR_DMATM	=	0x00000001,
115 	SATA_DWC_INTMR_NEWFPM	=	0x00000002,
116 	SATA_DWC_INTMR_PMABRTM	=	0x00000004,
117 	SATA_DWC_INTMR_ERRM	=	0x00000008,
118 	SATA_DWC_INTMR_NEWBISTM	=	0x00000010,
119 	SATA_DWC_LLCR_SCRAMEN	=	0x00000001,
120 	SATA_DWC_LLCR_DESCRAMEN	=	0x00000002,
121 	SATA_DWC_LLCR_RPDEN	=	0x00000004,
122 /* This is all error bits, zero's are reserved fields. */
123 	SATA_DWC_SERROR_ERR_BITS =	0x0FFF0F03
124 };
125 
126 #define SATA_DWC_SCR0_SPD_GET(v)	(((v) >> 4) & 0x0000000F)
127 #define SATA_DWC_DMACR_TX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_TXCHEN) |\
128 						 SATA_DWC_DMACR_TMOD_TXCHEN)
129 #define SATA_DWC_DMACR_RX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_RXCHEN) |\
130 						 SATA_DWC_DMACR_TMOD_TXCHEN)
131 #define SATA_DWC_DBTSR_MWR(size)	(((size)/4) & SATA_DWC_TXFIFO_DEPTH)
132 #define SATA_DWC_DBTSR_MRD(size)	((((size)/4) & SATA_DWC_RXFIFO_DEPTH)\
133 						 << 16)
134 struct sata_dwc_device {
135 	struct device		*dev;		/* generic device struct */
136 	struct ata_probe_ent	*pe;		/* ptr to probe-ent */
137 	struct ata_host		*host;
138 	struct sata_dwc_regs __iomem *sata_dwc_regs;	/* DW SATA specific */
139 	u32			sactive_issued;
140 	u32			sactive_queued;
141 	struct phy		*phy;
142 	phys_addr_t		dmadr;
143 #ifdef CONFIG_SATA_DWC_OLD_DMA
144 	struct dw_dma_chip	*dma;
145 #endif
146 };
147 
148 #define SATA_DWC_QCMD_MAX	32
149 
150 struct sata_dwc_device_port {
151 	struct sata_dwc_device	*hsdev;
152 	int			cmd_issued[SATA_DWC_QCMD_MAX];
153 	int			dma_pending[SATA_DWC_QCMD_MAX];
154 
155 	/* DMA info */
156 	struct dma_chan			*chan;
157 	struct dma_async_tx_descriptor	*desc[SATA_DWC_QCMD_MAX];
158 	u32				dma_interrupt_count;
159 };
160 
161 /*
162  * Commonly used DWC SATA driver macros
163  */
164 #define HSDEV_FROM_HOST(host)	((struct sata_dwc_device *)(host)->private_data)
165 #define HSDEV_FROM_AP(ap)	((struct sata_dwc_device *)(ap)->host->private_data)
166 #define HSDEVP_FROM_AP(ap)	((struct sata_dwc_device_port *)(ap)->private_data)
167 #define HSDEV_FROM_QC(qc)	((struct sata_dwc_device *)(qc)->ap->host->private_data)
168 #define HSDEV_FROM_HSDEVP(p)	((struct sata_dwc_device *)(p)->hsdev)
169 
170 enum {
171 	SATA_DWC_CMD_ISSUED_NOT		= 0,
172 	SATA_DWC_CMD_ISSUED_PEND	= 1,
173 	SATA_DWC_CMD_ISSUED_EXEC	= 2,
174 	SATA_DWC_CMD_ISSUED_NODATA	= 3,
175 
176 	SATA_DWC_DMA_PENDING_NONE	= 0,
177 	SATA_DWC_DMA_PENDING_TX		= 1,
178 	SATA_DWC_DMA_PENDING_RX		= 2,
179 };
180 
181 /*
182  * Prototypes
183  */
184 static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag);
185 static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
186 				u32 check_status);
187 static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status);
188 static void sata_dwc_port_stop(struct ata_port *ap);
189 static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag);
190 
191 #ifdef CONFIG_SATA_DWC_OLD_DMA
192 
193 #include <linux/platform_data/dma-dw.h>
194 #include <linux/dma/dw.h>
195 
196 static struct dw_dma_slave sata_dwc_dma_dws = {
197 	.src_id = 0,
198 	.dst_id = 0,
199 	.m_master = 1,
200 	.p_master = 0,
201 };
202 
203 static bool sata_dwc_dma_filter(struct dma_chan *chan, void *param)
204 {
205 	struct dw_dma_slave *dws = &sata_dwc_dma_dws;
206 
207 	if (dws->dma_dev != chan->device->dev)
208 		return false;
209 
210 	chan->private = dws;
211 	return true;
212 }
213 
214 static int sata_dwc_dma_get_channel_old(struct sata_dwc_device_port *hsdevp)
215 {
216 	struct sata_dwc_device *hsdev = hsdevp->hsdev;
217 	struct dw_dma_slave *dws = &sata_dwc_dma_dws;
218 	dma_cap_mask_t mask;
219 
220 	dws->dma_dev = hsdev->dev;
221 
222 	dma_cap_zero(mask);
223 	dma_cap_set(DMA_SLAVE, mask);
224 
225 	/* Acquire DMA channel */
226 	hsdevp->chan = dma_request_channel(mask, sata_dwc_dma_filter, hsdevp);
227 	if (!hsdevp->chan) {
228 		dev_err(hsdev->dev, "%s: dma channel unavailable\n",
229 			 __func__);
230 		return -EAGAIN;
231 	}
232 
233 	return 0;
234 }
235 
236 static int sata_dwc_dma_init_old(struct platform_device *pdev,
237 				 struct sata_dwc_device *hsdev)
238 {
239 	struct device_node *np = pdev->dev.of_node;
240 	struct resource *res;
241 
242 	hsdev->dma = devm_kzalloc(&pdev->dev, sizeof(*hsdev->dma), GFP_KERNEL);
243 	if (!hsdev->dma)
244 		return -ENOMEM;
245 
246 	hsdev->dma->dev = &pdev->dev;
247 	hsdev->dma->id = pdev->id;
248 
249 	/* Get SATA DMA interrupt number */
250 	hsdev->dma->irq = irq_of_parse_and_map(np, 1);
251 	if (hsdev->dma->irq == NO_IRQ) {
252 		dev_err(&pdev->dev, "no SATA DMA irq\n");
253 		return -ENODEV;
254 	}
255 
256 	/* Get physical SATA DMA register base address */
257 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
258 	hsdev->dma->regs = devm_ioremap_resource(&pdev->dev, res);
259 	if (IS_ERR(hsdev->dma->regs))
260 		return PTR_ERR(hsdev->dma->regs);
261 
262 	/* Initialize AHB DMAC */
263 	return dw_dma_probe(hsdev->dma);
264 }
265 
266 static void sata_dwc_dma_exit_old(struct sata_dwc_device *hsdev)
267 {
268 	if (!hsdev->dma)
269 		return;
270 
271 	dw_dma_remove(hsdev->dma);
272 }
273 
274 #endif
275 
276 static const char *get_prot_descript(u8 protocol)
277 {
278 	switch (protocol) {
279 	case ATA_PROT_NODATA:
280 		return "ATA no data";
281 	case ATA_PROT_PIO:
282 		return "ATA PIO";
283 	case ATA_PROT_DMA:
284 		return "ATA DMA";
285 	case ATA_PROT_NCQ:
286 		return "ATA NCQ";
287 	case ATA_PROT_NCQ_NODATA:
288 		return "ATA NCQ no data";
289 	case ATAPI_PROT_NODATA:
290 		return "ATAPI no data";
291 	case ATAPI_PROT_PIO:
292 		return "ATAPI PIO";
293 	case ATAPI_PROT_DMA:
294 		return "ATAPI DMA";
295 	default:
296 		return "unknown";
297 	}
298 }
299 
300 static const char *get_dma_dir_descript(int dma_dir)
301 {
302 	switch ((enum dma_data_direction)dma_dir) {
303 	case DMA_BIDIRECTIONAL:
304 		return "bidirectional";
305 	case DMA_TO_DEVICE:
306 		return "to device";
307 	case DMA_FROM_DEVICE:
308 		return "from device";
309 	default:
310 		return "none";
311 	}
312 }
313 
314 static void sata_dwc_tf_dump(struct ata_port *ap, struct ata_taskfile *tf)
315 {
316 	dev_vdbg(ap->dev,
317 		"taskfile cmd: 0x%02x protocol: %s flags: 0x%lx device: %x\n",
318 		tf->command, get_prot_descript(tf->protocol), tf->flags,
319 		tf->device);
320 	dev_vdbg(ap->dev,
321 		"feature: 0x%02x nsect: 0x%x lbal: 0x%x lbam: 0x%x lbah: 0x%x\n",
322 		tf->feature, tf->nsect, tf->lbal, tf->lbam, tf->lbah);
323 	dev_vdbg(ap->dev,
324 		"hob_feature: 0x%02x hob_nsect: 0x%x hob_lbal: 0x%x hob_lbam: 0x%x hob_lbah: 0x%x\n",
325 		tf->hob_feature, tf->hob_nsect, tf->hob_lbal, tf->hob_lbam,
326 		tf->hob_lbah);
327 }
328 
329 static void dma_dwc_xfer_done(void *hsdev_instance)
330 {
331 	unsigned long flags;
332 	struct sata_dwc_device *hsdev = hsdev_instance;
333 	struct ata_host *host = (struct ata_host *)hsdev->host;
334 	struct ata_port *ap;
335 	struct sata_dwc_device_port *hsdevp;
336 	u8 tag = 0;
337 	unsigned int port = 0;
338 
339 	spin_lock_irqsave(&host->lock, flags);
340 	ap = host->ports[port];
341 	hsdevp = HSDEVP_FROM_AP(ap);
342 	tag = ap->link.active_tag;
343 
344 	/*
345 	 * Each DMA command produces 2 interrupts.  Only
346 	 * complete the command after both interrupts have been
347 	 * seen. (See sata_dwc_isr())
348 	 */
349 	hsdevp->dma_interrupt_count++;
350 	sata_dwc_clear_dmacr(hsdevp, tag);
351 
352 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_NONE) {
353 		dev_err(ap->dev, "DMA not pending tag=0x%02x pending=%d\n",
354 			tag, hsdevp->dma_pending[tag]);
355 	}
356 
357 	if ((hsdevp->dma_interrupt_count % 2) == 0)
358 		sata_dwc_dma_xfer_complete(ap, 1);
359 
360 	spin_unlock_irqrestore(&host->lock, flags);
361 }
362 
363 static struct dma_async_tx_descriptor *dma_dwc_xfer_setup(struct ata_queued_cmd *qc)
364 {
365 	struct ata_port *ap = qc->ap;
366 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
367 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
368 	struct dma_slave_config sconf;
369 	struct dma_async_tx_descriptor *desc;
370 
371 	if (qc->dma_dir == DMA_DEV_TO_MEM) {
372 		sconf.src_addr = hsdev->dmadr;
373 		sconf.device_fc = false;
374 	} else {	/* DMA_MEM_TO_DEV */
375 		sconf.dst_addr = hsdev->dmadr;
376 		sconf.device_fc = false;
377 	}
378 
379 	sconf.direction = qc->dma_dir;
380 	sconf.src_maxburst = AHB_DMA_BRST_DFLT / 4;	/* in items */
381 	sconf.dst_maxburst = AHB_DMA_BRST_DFLT / 4;	/* in items */
382 	sconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
383 	sconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
384 
385 	dmaengine_slave_config(hsdevp->chan, &sconf);
386 
387 	/* Convert SG list to linked list of items (LLIs) for AHB DMA */
388 	desc = dmaengine_prep_slave_sg(hsdevp->chan, qc->sg, qc->n_elem,
389 				       qc->dma_dir,
390 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
391 
392 	if (!desc)
393 		return NULL;
394 
395 	desc->callback = dma_dwc_xfer_done;
396 	desc->callback_param = hsdev;
397 
398 	dev_dbg(hsdev->dev, "%s sg: 0x%p, count: %d addr: %pa\n", __func__,
399 		qc->sg, qc->n_elem, &hsdev->dmadr);
400 
401 	return desc;
402 }
403 
404 static int sata_dwc_scr_read(struct ata_link *link, unsigned int scr, u32 *val)
405 {
406 	if (scr > SCR_NOTIFICATION) {
407 		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
408 			__func__, scr);
409 		return -EINVAL;
410 	}
411 
412 	*val = sata_dwc_readl(link->ap->ioaddr.scr_addr + (scr * 4));
413 	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=0x%08x\n", __func__,
414 		link->ap->print_id, scr, *val);
415 
416 	return 0;
417 }
418 
419 static int sata_dwc_scr_write(struct ata_link *link, unsigned int scr, u32 val)
420 {
421 	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=0x%08x\n", __func__,
422 		link->ap->print_id, scr, val);
423 	if (scr > SCR_NOTIFICATION) {
424 		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
425 			 __func__, scr);
426 		return -EINVAL;
427 	}
428 	sata_dwc_writel(link->ap->ioaddr.scr_addr + (scr * 4), val);
429 
430 	return 0;
431 }
432 
433 static void clear_serror(struct ata_port *ap)
434 {
435 	u32 val;
436 	sata_dwc_scr_read(&ap->link, SCR_ERROR, &val);
437 	sata_dwc_scr_write(&ap->link, SCR_ERROR, val);
438 }
439 
440 static void clear_interrupt_bit(struct sata_dwc_device *hsdev, u32 bit)
441 {
442 	sata_dwc_writel(&hsdev->sata_dwc_regs->intpr,
443 			sata_dwc_readl(&hsdev->sata_dwc_regs->intpr));
444 }
445 
446 static u32 qcmd_tag_to_mask(u8 tag)
447 {
448 	return 0x00000001 << (tag & 0x1f);
449 }
450 
451 /* See ahci.c */
452 static void sata_dwc_error_intr(struct ata_port *ap,
453 				struct sata_dwc_device *hsdev, uint intpr)
454 {
455 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
456 	struct ata_eh_info *ehi = &ap->link.eh_info;
457 	unsigned int err_mask = 0, action = 0;
458 	struct ata_queued_cmd *qc;
459 	u32 serror;
460 	u8 status, tag;
461 
462 	ata_ehi_clear_desc(ehi);
463 
464 	sata_dwc_scr_read(&ap->link, SCR_ERROR, &serror);
465 	status = ap->ops->sff_check_status(ap);
466 
467 	tag = ap->link.active_tag;
468 
469 	dev_err(ap->dev,
470 		"%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x dma_intp=%d pending=%d issued=%d",
471 		__func__, serror, intpr, status, hsdevp->dma_interrupt_count,
472 		hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag]);
473 
474 	/* Clear error register and interrupt bit */
475 	clear_serror(ap);
476 	clear_interrupt_bit(hsdev, SATA_DWC_INTPR_ERR);
477 
478 	/* This is the only error happening now.  TODO check for exact error */
479 
480 	err_mask |= AC_ERR_HOST_BUS;
481 	action |= ATA_EH_RESET;
482 
483 	/* Pass this on to EH */
484 	ehi->serror |= serror;
485 	ehi->action |= action;
486 
487 	qc = ata_qc_from_tag(ap, tag);
488 	if (qc)
489 		qc->err_mask |= err_mask;
490 	else
491 		ehi->err_mask |= err_mask;
492 
493 	ata_port_abort(ap);
494 }
495 
496 /*
497  * Function : sata_dwc_isr
498  * arguments : irq, void *dev_instance, struct pt_regs *regs
499  * Return value : irqreturn_t - status of IRQ
500  * This Interrupt handler called via port ops registered function.
501  * .irq_handler = sata_dwc_isr
502  */
503 static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)
504 {
505 	struct ata_host *host = (struct ata_host *)dev_instance;
506 	struct sata_dwc_device *hsdev = HSDEV_FROM_HOST(host);
507 	struct ata_port *ap;
508 	struct ata_queued_cmd *qc;
509 	unsigned long flags;
510 	u8 status, tag;
511 	int handled, num_processed, port = 0;
512 	uint intpr, sactive, sactive2, tag_mask;
513 	struct sata_dwc_device_port *hsdevp;
514 	hsdev->sactive_issued = 0;
515 
516 	spin_lock_irqsave(&host->lock, flags);
517 
518 	/* Read the interrupt register */
519 	intpr = sata_dwc_readl(&hsdev->sata_dwc_regs->intpr);
520 
521 	ap = host->ports[port];
522 	hsdevp = HSDEVP_FROM_AP(ap);
523 
524 	dev_dbg(ap->dev, "%s intpr=0x%08x active_tag=%d\n", __func__, intpr,
525 		ap->link.active_tag);
526 
527 	/* Check for error interrupt */
528 	if (intpr & SATA_DWC_INTPR_ERR) {
529 		sata_dwc_error_intr(ap, hsdev, intpr);
530 		handled = 1;
531 		goto DONE;
532 	}
533 
534 	/* Check for DMA SETUP FIS (FP DMA) interrupt */
535 	if (intpr & SATA_DWC_INTPR_NEWFP) {
536 		clear_interrupt_bit(hsdev, SATA_DWC_INTPR_NEWFP);
537 
538 		tag = (u8)(sata_dwc_readl(&hsdev->sata_dwc_regs->fptagr));
539 		dev_dbg(ap->dev, "%s: NEWFP tag=%d\n", __func__, tag);
540 		if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_PEND)
541 			dev_warn(ap->dev, "CMD tag=%d not pending?\n", tag);
542 
543 		hsdev->sactive_issued |= qcmd_tag_to_mask(tag);
544 
545 		qc = ata_qc_from_tag(ap, tag);
546 		/*
547 		 * Start FP DMA for NCQ command.  At this point the tag is the
548 		 * active tag.  It is the tag that matches the command about to
549 		 * be completed.
550 		 */
551 		qc->ap->link.active_tag = tag;
552 		sata_dwc_bmdma_start_by_tag(qc, tag);
553 
554 		handled = 1;
555 		goto DONE;
556 	}
557 	sata_dwc_scr_read(&ap->link, SCR_ACTIVE, &sactive);
558 	tag_mask = (hsdev->sactive_issued | sactive) ^ sactive;
559 
560 	/* If no sactive issued and tag_mask is zero then this is not NCQ */
561 	if (hsdev->sactive_issued == 0 && tag_mask == 0) {
562 		if (ap->link.active_tag == ATA_TAG_POISON)
563 			tag = 0;
564 		else
565 			tag = ap->link.active_tag;
566 		qc = ata_qc_from_tag(ap, tag);
567 
568 		/* DEV interrupt w/ no active qc? */
569 		if (unlikely(!qc || (qc->tf.flags & ATA_TFLAG_POLLING))) {
570 			dev_err(ap->dev,
571 				"%s interrupt with no active qc qc=%p\n",
572 				__func__, qc);
573 			ap->ops->sff_check_status(ap);
574 			handled = 1;
575 			goto DONE;
576 		}
577 		status = ap->ops->sff_check_status(ap);
578 
579 		qc->ap->link.active_tag = tag;
580 		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
581 
582 		if (status & ATA_ERR) {
583 			dev_dbg(ap->dev, "interrupt ATA_ERR (0x%x)\n", status);
584 			sata_dwc_qc_complete(ap, qc, 1);
585 			handled = 1;
586 			goto DONE;
587 		}
588 
589 		dev_dbg(ap->dev, "%s non-NCQ cmd interrupt, protocol: %s\n",
590 			__func__, get_prot_descript(qc->tf.protocol));
591 DRVSTILLBUSY:
592 		if (ata_is_dma(qc->tf.protocol)) {
593 			/*
594 			 * Each DMA transaction produces 2 interrupts. The DMAC
595 			 * transfer complete interrupt and the SATA controller
596 			 * operation done interrupt. The command should be
597 			 * completed only after both interrupts are seen.
598 			 */
599 			hsdevp->dma_interrupt_count++;
600 			if (hsdevp->dma_pending[tag] == \
601 					SATA_DWC_DMA_PENDING_NONE) {
602 				dev_err(ap->dev,
603 					"%s: DMA not pending intpr=0x%08x status=0x%08x pending=%d\n",
604 					__func__, intpr, status,
605 					hsdevp->dma_pending[tag]);
606 			}
607 
608 			if ((hsdevp->dma_interrupt_count % 2) == 0)
609 				sata_dwc_dma_xfer_complete(ap, 1);
610 		} else if (ata_is_pio(qc->tf.protocol)) {
611 			ata_sff_hsm_move(ap, qc, status, 0);
612 			handled = 1;
613 			goto DONE;
614 		} else {
615 			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
616 				goto DRVSTILLBUSY;
617 		}
618 
619 		handled = 1;
620 		goto DONE;
621 	}
622 
623 	/*
624 	 * This is a NCQ command. At this point we need to figure out for which
625 	 * tags we have gotten a completion interrupt.  One interrupt may serve
626 	 * as completion for more than one operation when commands are queued
627 	 * (NCQ).  We need to process each completed command.
628 	 */
629 
630 	 /* process completed commands */
631 	sata_dwc_scr_read(&ap->link, SCR_ACTIVE, &sactive);
632 	tag_mask = (hsdev->sactive_issued | sactive) ^ sactive;
633 
634 	if (sactive != 0 || hsdev->sactive_issued > 1 || tag_mask > 1) {
635 		dev_dbg(ap->dev,
636 			"%s NCQ:sactive=0x%08x  sactive_issued=0x%08x tag_mask=0x%08x\n",
637 			__func__, sactive, hsdev->sactive_issued, tag_mask);
638 	}
639 
640 	if ((tag_mask | hsdev->sactive_issued) != hsdev->sactive_issued) {
641 		dev_warn(ap->dev,
642 			 "Bad tag mask?  sactive=0x%08x sactive_issued=0x%08x  tag_mask=0x%08x\n",
643 			 sactive, hsdev->sactive_issued, tag_mask);
644 	}
645 
646 	/* read just to clear ... not bad if currently still busy */
647 	status = ap->ops->sff_check_status(ap);
648 	dev_dbg(ap->dev, "%s ATA status register=0x%x\n", __func__, status);
649 
650 	tag = 0;
651 	num_processed = 0;
652 	while (tag_mask) {
653 		num_processed++;
654 		while (!(tag_mask & 0x00000001)) {
655 			tag++;
656 			tag_mask <<= 1;
657 		}
658 
659 		tag_mask &= (~0x00000001);
660 		qc = ata_qc_from_tag(ap, tag);
661 
662 		/* To be picked up by completion functions */
663 		qc->ap->link.active_tag = tag;
664 		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
665 
666 		/* Let libata/scsi layers handle error */
667 		if (status & ATA_ERR) {
668 			dev_dbg(ap->dev, "%s ATA_ERR (0x%x)\n", __func__,
669 				status);
670 			sata_dwc_qc_complete(ap, qc, 1);
671 			handled = 1;
672 			goto DONE;
673 		}
674 
675 		/* Process completed command */
676 		dev_dbg(ap->dev, "%s NCQ command, protocol: %s\n", __func__,
677 			get_prot_descript(qc->tf.protocol));
678 		if (ata_is_dma(qc->tf.protocol)) {
679 			hsdevp->dma_interrupt_count++;
680 			if (hsdevp->dma_pending[tag] == \
681 					SATA_DWC_DMA_PENDING_NONE)
682 				dev_warn(ap->dev, "%s: DMA not pending?\n",
683 					__func__);
684 			if ((hsdevp->dma_interrupt_count % 2) == 0)
685 				sata_dwc_dma_xfer_complete(ap, 1);
686 		} else {
687 			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
688 				goto STILLBUSY;
689 		}
690 		continue;
691 
692 STILLBUSY:
693 		ap->stats.idle_irq++;
694 		dev_warn(ap->dev, "STILL BUSY IRQ ata%d: irq trap\n",
695 			ap->print_id);
696 	} /* while tag_mask */
697 
698 	/*
699 	 * Check to see if any commands completed while we were processing our
700 	 * initial set of completed commands (read status clears interrupts,
701 	 * so we might miss a completed command interrupt if one came in while
702 	 * we were processing --we read status as part of processing a completed
703 	 * command).
704 	 */
705 	sata_dwc_scr_read(&ap->link, SCR_ACTIVE, &sactive2);
706 	if (sactive2 != sactive) {
707 		dev_dbg(ap->dev,
708 			"More completed - sactive=0x%x sactive2=0x%x\n",
709 			sactive, sactive2);
710 	}
711 	handled = 1;
712 
713 DONE:
714 	spin_unlock_irqrestore(&host->lock, flags);
715 	return IRQ_RETVAL(handled);
716 }
717 
718 static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag)
719 {
720 	struct sata_dwc_device *hsdev = HSDEV_FROM_HSDEVP(hsdevp);
721 	u32 dmacr = sata_dwc_readl(&hsdev->sata_dwc_regs->dmacr);
722 
723 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX) {
724 		dmacr = SATA_DWC_DMACR_RX_CLEAR(dmacr);
725 		sata_dwc_writel(&hsdev->sata_dwc_regs->dmacr, dmacr);
726 	} else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX) {
727 		dmacr = SATA_DWC_DMACR_TX_CLEAR(dmacr);
728 		sata_dwc_writel(&hsdev->sata_dwc_regs->dmacr, dmacr);
729 	} else {
730 		/*
731 		 * This should not happen, it indicates the driver is out of
732 		 * sync.  If it does happen, clear dmacr anyway.
733 		 */
734 		dev_err(hsdev->dev,
735 			"%s DMA protocol RX and TX DMA not pending tag=0x%02x pending=%d dmacr: 0x%08x\n",
736 			__func__, tag, hsdevp->dma_pending[tag], dmacr);
737 		sata_dwc_writel(&hsdev->sata_dwc_regs->dmacr,
738 				SATA_DWC_DMACR_TXRXCH_CLEAR);
739 	}
740 }
741 
742 static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status)
743 {
744 	struct ata_queued_cmd *qc;
745 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
746 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
747 	u8 tag = 0;
748 
749 	tag = ap->link.active_tag;
750 	qc = ata_qc_from_tag(ap, tag);
751 	if (!qc) {
752 		dev_err(ap->dev, "failed to get qc");
753 		return;
754 	}
755 
756 #ifdef DEBUG_NCQ
757 	if (tag > 0) {
758 		dev_info(ap->dev,
759 			 "%s tag=%u cmd=0x%02x dma dir=%s proto=%s dmacr=0x%08x\n",
760 			 __func__, qc->hw_tag, qc->tf.command,
761 			 get_dma_dir_descript(qc->dma_dir),
762 			 get_prot_descript(qc->tf.protocol),
763 			 sata_dwc_readl(&hsdev->sata_dwc_regs->dmacr));
764 	}
765 #endif
766 
767 	if (ata_is_dma(qc->tf.protocol)) {
768 		if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_NONE) {
769 			dev_err(ap->dev,
770 				"%s DMA protocol RX and TX DMA not pending dmacr: 0x%08x\n",
771 				__func__,
772 				sata_dwc_readl(&hsdev->sata_dwc_regs->dmacr));
773 		}
774 
775 		hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_NONE;
776 		sata_dwc_qc_complete(ap, qc, check_status);
777 		ap->link.active_tag = ATA_TAG_POISON;
778 	} else {
779 		sata_dwc_qc_complete(ap, qc, check_status);
780 	}
781 }
782 
783 static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
784 				u32 check_status)
785 {
786 	u8 status = 0;
787 	u32 mask = 0x0;
788 	u8 tag = qc->hw_tag;
789 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
790 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
791 	hsdev->sactive_queued = 0;
792 	dev_dbg(ap->dev, "%s checkstatus? %x\n", __func__, check_status);
793 
794 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX)
795 		dev_err(ap->dev, "TX DMA PENDING\n");
796 	else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX)
797 		dev_err(ap->dev, "RX DMA PENDING\n");
798 	dev_dbg(ap->dev,
799 		"QC complete cmd=0x%02x status=0x%02x ata%u: protocol=%d\n",
800 		qc->tf.command, status, ap->print_id, qc->tf.protocol);
801 
802 	/* clear active bit */
803 	mask = (~(qcmd_tag_to_mask(tag)));
804 	hsdev->sactive_queued = hsdev->sactive_queued & mask;
805 	hsdev->sactive_issued = hsdev->sactive_issued & mask;
806 	ata_qc_complete(qc);
807 	return 0;
808 }
809 
810 static void sata_dwc_enable_interrupts(struct sata_dwc_device *hsdev)
811 {
812 	/* Enable selective interrupts by setting the interrupt maskregister*/
813 	sata_dwc_writel(&hsdev->sata_dwc_regs->intmr,
814 			SATA_DWC_INTMR_ERRM |
815 			SATA_DWC_INTMR_NEWFPM |
816 			SATA_DWC_INTMR_PMABRTM |
817 			SATA_DWC_INTMR_DMATM);
818 	/*
819 	 * Unmask the error bits that should trigger an error interrupt by
820 	 * setting the error mask register.
821 	 */
822 	sata_dwc_writel(&hsdev->sata_dwc_regs->errmr, SATA_DWC_SERROR_ERR_BITS);
823 
824 	dev_dbg(hsdev->dev, "%s: INTMR = 0x%08x, ERRMR = 0x%08x\n",
825 		 __func__, sata_dwc_readl(&hsdev->sata_dwc_regs->intmr),
826 		sata_dwc_readl(&hsdev->sata_dwc_regs->errmr));
827 }
828 
829 static void sata_dwc_setup_port(struct ata_ioports *port, void __iomem *base)
830 {
831 	port->cmd_addr		= base + 0x00;
832 	port->data_addr		= base + 0x00;
833 
834 	port->error_addr	= base + 0x04;
835 	port->feature_addr	= base + 0x04;
836 
837 	port->nsect_addr	= base + 0x08;
838 
839 	port->lbal_addr		= base + 0x0c;
840 	port->lbam_addr		= base + 0x10;
841 	port->lbah_addr		= base + 0x14;
842 
843 	port->device_addr	= base + 0x18;
844 	port->command_addr	= base + 0x1c;
845 	port->status_addr	= base + 0x1c;
846 
847 	port->altstatus_addr	= base + 0x20;
848 	port->ctl_addr		= base + 0x20;
849 }
850 
851 static int sata_dwc_dma_get_channel(struct sata_dwc_device_port *hsdevp)
852 {
853 	struct sata_dwc_device *hsdev = hsdevp->hsdev;
854 	struct device *dev = hsdev->dev;
855 
856 #ifdef CONFIG_SATA_DWC_OLD_DMA
857 	if (!of_find_property(dev->of_node, "dmas", NULL))
858 		return sata_dwc_dma_get_channel_old(hsdevp);
859 #endif
860 
861 	hsdevp->chan = dma_request_chan(dev, "sata-dma");
862 	if (IS_ERR(hsdevp->chan)) {
863 		dev_err(dev, "failed to allocate dma channel: %ld\n",
864 			PTR_ERR(hsdevp->chan));
865 		return PTR_ERR(hsdevp->chan);
866 	}
867 
868 	return 0;
869 }
870 
871 /*
872  * Function : sata_dwc_port_start
873  * arguments : struct ata_ioports *port
874  * Return value : returns 0 if success, error code otherwise
875  * This function allocates the scatter gather LLI table for AHB DMA
876  */
877 static int sata_dwc_port_start(struct ata_port *ap)
878 {
879 	int err = 0;
880 	struct sata_dwc_device *hsdev;
881 	struct sata_dwc_device_port *hsdevp = NULL;
882 	struct device *pdev;
883 	int i;
884 
885 	hsdev = HSDEV_FROM_AP(ap);
886 
887 	dev_dbg(ap->dev, "%s: port_no=%d\n", __func__, ap->port_no);
888 
889 	hsdev->host = ap->host;
890 	pdev = ap->host->dev;
891 	if (!pdev) {
892 		dev_err(ap->dev, "%s: no ap->host->dev\n", __func__);
893 		err = -ENODEV;
894 		goto CLEANUP;
895 	}
896 
897 	/* Allocate Port Struct */
898 	hsdevp = kzalloc(sizeof(*hsdevp), GFP_KERNEL);
899 	if (!hsdevp) {
900 		err = -ENOMEM;
901 		goto CLEANUP;
902 	}
903 	hsdevp->hsdev = hsdev;
904 
905 	err = sata_dwc_dma_get_channel(hsdevp);
906 	if (err)
907 		goto CLEANUP_ALLOC;
908 
909 	err = phy_power_on(hsdev->phy);
910 	if (err)
911 		goto CLEANUP_ALLOC;
912 
913 	for (i = 0; i < SATA_DWC_QCMD_MAX; i++)
914 		hsdevp->cmd_issued[i] = SATA_DWC_CMD_ISSUED_NOT;
915 
916 	ap->bmdma_prd = NULL;	/* set these so libata doesn't use them */
917 	ap->bmdma_prd_dma = 0;
918 
919 	if (ap->port_no == 0)  {
920 		dev_dbg(ap->dev, "%s: clearing TXCHEN, RXCHEN in DMAC\n",
921 			__func__);
922 		sata_dwc_writel(&hsdev->sata_dwc_regs->dmacr,
923 				SATA_DWC_DMACR_TXRXCH_CLEAR);
924 
925 		dev_dbg(ap->dev, "%s: setting burst size in DBTSR\n",
926 			 __func__);
927 		sata_dwc_writel(&hsdev->sata_dwc_regs->dbtsr,
928 				(SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
929 				 SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT)));
930 	}
931 
932 	/* Clear any error bits before libata starts issuing commands */
933 	clear_serror(ap);
934 	ap->private_data = hsdevp;
935 	dev_dbg(ap->dev, "%s: done\n", __func__);
936 	return 0;
937 
938 CLEANUP_ALLOC:
939 	kfree(hsdevp);
940 CLEANUP:
941 	dev_dbg(ap->dev, "%s: fail. ap->id = %d\n", __func__, ap->print_id);
942 	return err;
943 }
944 
945 static void sata_dwc_port_stop(struct ata_port *ap)
946 {
947 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
948 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
949 
950 	dev_dbg(ap->dev, "%s: ap->id = %d\n", __func__, ap->print_id);
951 
952 	dmaengine_terminate_sync(hsdevp->chan);
953 	dma_release_channel(hsdevp->chan);
954 	phy_power_off(hsdev->phy);
955 
956 	kfree(hsdevp);
957 	ap->private_data = NULL;
958 }
959 
960 /*
961  * Function : sata_dwc_exec_command_by_tag
962  * arguments : ata_port *ap, ata_taskfile *tf, u8 tag, u32 cmd_issued
963  * Return value : None
964  * This function keeps track of individual command tag ids and calls
965  * ata_exec_command in libata
966  */
967 static void sata_dwc_exec_command_by_tag(struct ata_port *ap,
968 					 struct ata_taskfile *tf,
969 					 u8 tag, u32 cmd_issued)
970 {
971 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
972 
973 	dev_dbg(ap->dev, "%s cmd(0x%02x): %s tag=%d\n", __func__, tf->command,
974 		ata_get_cmd_descript(tf->command), tag);
975 
976 	hsdevp->cmd_issued[tag] = cmd_issued;
977 
978 	/*
979 	 * Clear SError before executing a new command.
980 	 * sata_dwc_scr_write and read can not be used here. Clearing the PM
981 	 * managed SError register for the disk needs to be done before the
982 	 * task file is loaded.
983 	 */
984 	clear_serror(ap);
985 	ata_sff_exec_command(ap, tf);
986 }
987 
988 static void sata_dwc_bmdma_setup_by_tag(struct ata_queued_cmd *qc, u8 tag)
989 {
990 	sata_dwc_exec_command_by_tag(qc->ap, &qc->tf, tag,
991 				     SATA_DWC_CMD_ISSUED_PEND);
992 }
993 
994 static void sata_dwc_bmdma_setup(struct ata_queued_cmd *qc)
995 {
996 	u8 tag = qc->hw_tag;
997 
998 	if (ata_is_ncq(qc->tf.protocol)) {
999 		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
1000 			__func__, qc->ap->link.sactive, tag);
1001 	} else {
1002 		tag = 0;
1003 	}
1004 	sata_dwc_bmdma_setup_by_tag(qc, tag);
1005 }
1006 
1007 static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag)
1008 {
1009 	int start_dma;
1010 	u32 reg;
1011 	struct sata_dwc_device *hsdev = HSDEV_FROM_QC(qc);
1012 	struct ata_port *ap = qc->ap;
1013 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1014 	struct dma_async_tx_descriptor *desc = hsdevp->desc[tag];
1015 	int dir = qc->dma_dir;
1016 
1017 	if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_NOT) {
1018 		start_dma = 1;
1019 		if (dir == DMA_TO_DEVICE)
1020 			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_TX;
1021 		else
1022 			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_RX;
1023 	} else {
1024 		dev_err(ap->dev,
1025 			"%s: Command not pending cmd_issued=%d (tag=%d) DMA NOT started\n",
1026 			__func__, hsdevp->cmd_issued[tag], tag);
1027 		start_dma = 0;
1028 	}
1029 
1030 	dev_dbg(ap->dev,
1031 		"%s qc=%p tag: %x cmd: 0x%02x dma_dir: %s start_dma? %x\n",
1032 		__func__, qc, tag, qc->tf.command,
1033 		get_dma_dir_descript(qc->dma_dir), start_dma);
1034 	sata_dwc_tf_dump(ap, &qc->tf);
1035 
1036 	if (start_dma) {
1037 		sata_dwc_scr_read(&ap->link, SCR_ERROR, &reg);
1038 		if (reg & SATA_DWC_SERROR_ERR_BITS) {
1039 			dev_err(ap->dev, "%s: ****** SError=0x%08x ******\n",
1040 				__func__, reg);
1041 		}
1042 
1043 		if (dir == DMA_TO_DEVICE)
1044 			sata_dwc_writel(&hsdev->sata_dwc_regs->dmacr,
1045 					SATA_DWC_DMACR_TXCHEN);
1046 		else
1047 			sata_dwc_writel(&hsdev->sata_dwc_regs->dmacr,
1048 					SATA_DWC_DMACR_RXCHEN);
1049 
1050 		/* Enable AHB DMA transfer on the specified channel */
1051 		dmaengine_submit(desc);
1052 		dma_async_issue_pending(hsdevp->chan);
1053 	}
1054 }
1055 
1056 static void sata_dwc_bmdma_start(struct ata_queued_cmd *qc)
1057 {
1058 	u8 tag = qc->hw_tag;
1059 
1060 	if (ata_is_ncq(qc->tf.protocol)) {
1061 		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
1062 			__func__, qc->ap->link.sactive, tag);
1063 	} else {
1064 		tag = 0;
1065 	}
1066 	dev_dbg(qc->ap->dev, "%s\n", __func__);
1067 	sata_dwc_bmdma_start_by_tag(qc, tag);
1068 }
1069 
1070 static unsigned int sata_dwc_qc_issue(struct ata_queued_cmd *qc)
1071 {
1072 	u32 sactive;
1073 	u8 tag = qc->hw_tag;
1074 	struct ata_port *ap = qc->ap;
1075 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1076 
1077 #ifdef DEBUG_NCQ
1078 	if (qc->hw_tag > 0 || ap->link.sactive > 1)
1079 		dev_info(ap->dev,
1080 			 "%s ap id=%d cmd(0x%02x)=%s qc tag=%d prot=%s ap active_tag=0x%08x ap sactive=0x%08x\n",
1081 			 __func__, ap->print_id, qc->tf.command,
1082 			 ata_get_cmd_descript(qc->tf.command),
1083 			 qc->hw_tag, get_prot_descript(qc->tf.protocol),
1084 			 ap->link.active_tag, ap->link.sactive);
1085 #endif
1086 
1087 	if (!ata_is_ncq(qc->tf.protocol))
1088 		tag = 0;
1089 
1090 	if (ata_is_dma(qc->tf.protocol)) {
1091 		hsdevp->desc[tag] = dma_dwc_xfer_setup(qc);
1092 		if (!hsdevp->desc[tag])
1093 			return AC_ERR_SYSTEM;
1094 	} else {
1095 		hsdevp->desc[tag] = NULL;
1096 	}
1097 
1098 	if (ata_is_ncq(qc->tf.protocol)) {
1099 		sata_dwc_scr_read(&ap->link, SCR_ACTIVE, &sactive);
1100 		sactive |= (0x00000001 << tag);
1101 		sata_dwc_scr_write(&ap->link, SCR_ACTIVE, sactive);
1102 
1103 		dev_dbg(qc->ap->dev,
1104 			"%s: tag=%d ap->link.sactive = 0x%08x sactive=0x%08x\n",
1105 			__func__, tag, qc->ap->link.sactive, sactive);
1106 
1107 		ap->ops->sff_tf_load(ap, &qc->tf);
1108 		sata_dwc_exec_command_by_tag(ap, &qc->tf, tag,
1109 					     SATA_DWC_CMD_ISSUED_PEND);
1110 	} else {
1111 		return ata_bmdma_qc_issue(qc);
1112 	}
1113 	return 0;
1114 }
1115 
1116 static void sata_dwc_error_handler(struct ata_port *ap)
1117 {
1118 	ata_sff_error_handler(ap);
1119 }
1120 
1121 static int sata_dwc_hardreset(struct ata_link *link, unsigned int *class,
1122 			      unsigned long deadline)
1123 {
1124 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(link->ap);
1125 	int ret;
1126 
1127 	ret = sata_sff_hardreset(link, class, deadline);
1128 
1129 	sata_dwc_enable_interrupts(hsdev);
1130 
1131 	/* Reconfigure the DMA control register */
1132 	sata_dwc_writel(&hsdev->sata_dwc_regs->dmacr,
1133 			SATA_DWC_DMACR_TXRXCH_CLEAR);
1134 
1135 	/* Reconfigure the DMA Burst Transaction Size register */
1136 	sata_dwc_writel(&hsdev->sata_dwc_regs->dbtsr,
1137 			SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
1138 			SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT));
1139 
1140 	return ret;
1141 }
1142 
1143 static void sata_dwc_dev_select(struct ata_port *ap, unsigned int device)
1144 {
1145 	/* SATA DWC is master only */
1146 }
1147 
1148 /*
1149  * scsi mid-layer and libata interface structures
1150  */
1151 static struct scsi_host_template sata_dwc_sht = {
1152 	ATA_NCQ_SHT(DRV_NAME),
1153 	/*
1154 	 * test-only: Currently this driver doesn't handle NCQ
1155 	 * correctly. We enable NCQ but set the queue depth to a
1156 	 * max of 1. This will get fixed in in a future release.
1157 	 */
1158 	.sg_tablesize		= LIBATA_MAX_PRD,
1159 	/* .can_queue		= ATA_MAX_QUEUE, */
1160 	/*
1161 	 * Make sure a LLI block is not created that will span 8K max FIS
1162 	 * boundary. If the block spans such a FIS boundary, there is a chance
1163 	 * that a DMA burst will cross that boundary -- this results in an
1164 	 * error in the host controller.
1165 	 */
1166 	.dma_boundary		= 0x1fff /* ATA_DMA_BOUNDARY */,
1167 };
1168 
1169 static struct ata_port_operations sata_dwc_ops = {
1170 	.inherits		= &ata_sff_port_ops,
1171 
1172 	.error_handler		= sata_dwc_error_handler,
1173 	.hardreset		= sata_dwc_hardreset,
1174 
1175 	.qc_issue		= sata_dwc_qc_issue,
1176 
1177 	.scr_read		= sata_dwc_scr_read,
1178 	.scr_write		= sata_dwc_scr_write,
1179 
1180 	.port_start		= sata_dwc_port_start,
1181 	.port_stop		= sata_dwc_port_stop,
1182 
1183 	.sff_dev_select		= sata_dwc_dev_select,
1184 
1185 	.bmdma_setup		= sata_dwc_bmdma_setup,
1186 	.bmdma_start		= sata_dwc_bmdma_start,
1187 };
1188 
1189 static const struct ata_port_info sata_dwc_port_info[] = {
1190 	{
1191 		.flags		= ATA_FLAG_SATA | ATA_FLAG_NCQ,
1192 		.pio_mask	= ATA_PIO4,
1193 		.udma_mask	= ATA_UDMA6,
1194 		.port_ops	= &sata_dwc_ops,
1195 	},
1196 };
1197 
1198 static int sata_dwc_probe(struct platform_device *ofdev)
1199 {
1200 	struct sata_dwc_device *hsdev;
1201 	u32 idr, versionr;
1202 	char *ver = (char *)&versionr;
1203 	void __iomem *base;
1204 	int err = 0;
1205 	int irq;
1206 	struct ata_host *host;
1207 	struct ata_port_info pi = sata_dwc_port_info[0];
1208 	const struct ata_port_info *ppi[] = { &pi, NULL };
1209 	struct device_node *np = ofdev->dev.of_node;
1210 	struct resource *res;
1211 
1212 	/* Allocate DWC SATA device */
1213 	host = ata_host_alloc_pinfo(&ofdev->dev, ppi, SATA_DWC_MAX_PORTS);
1214 	hsdev = devm_kzalloc(&ofdev->dev, sizeof(*hsdev), GFP_KERNEL);
1215 	if (!host || !hsdev)
1216 		return -ENOMEM;
1217 
1218 	host->private_data = hsdev;
1219 
1220 	/* Ioremap SATA registers */
1221 	res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
1222 	base = devm_ioremap_resource(&ofdev->dev, res);
1223 	if (IS_ERR(base))
1224 		return PTR_ERR(base);
1225 	dev_dbg(&ofdev->dev, "ioremap done for SATA register address\n");
1226 
1227 	/* Synopsys DWC SATA specific Registers */
1228 	hsdev->sata_dwc_regs = base + SATA_DWC_REG_OFFSET;
1229 	hsdev->dmadr = res->start + SATA_DWC_REG_OFFSET + offsetof(struct sata_dwc_regs, dmadr);
1230 
1231 	/* Setup port */
1232 	host->ports[0]->ioaddr.cmd_addr = base;
1233 	host->ports[0]->ioaddr.scr_addr = base + SATA_DWC_SCR_OFFSET;
1234 	sata_dwc_setup_port(&host->ports[0]->ioaddr, base);
1235 
1236 	/* Read the ID and Version Registers */
1237 	idr = sata_dwc_readl(&hsdev->sata_dwc_regs->idr);
1238 	versionr = sata_dwc_readl(&hsdev->sata_dwc_regs->versionr);
1239 	dev_notice(&ofdev->dev, "id %d, controller version %c.%c%c\n",
1240 		   idr, ver[0], ver[1], ver[2]);
1241 
1242 	/* Save dev for later use in dev_xxx() routines */
1243 	hsdev->dev = &ofdev->dev;
1244 
1245 	/* Enable SATA Interrupts */
1246 	sata_dwc_enable_interrupts(hsdev);
1247 
1248 	/* Get SATA interrupt number */
1249 	irq = irq_of_parse_and_map(np, 0);
1250 	if (irq == NO_IRQ) {
1251 		dev_err(&ofdev->dev, "no SATA DMA irq\n");
1252 		err = -ENODEV;
1253 		goto error_out;
1254 	}
1255 
1256 #ifdef CONFIG_SATA_DWC_OLD_DMA
1257 	if (!of_find_property(np, "dmas", NULL)) {
1258 		err = sata_dwc_dma_init_old(ofdev, hsdev);
1259 		if (err)
1260 			goto error_out;
1261 	}
1262 #endif
1263 
1264 	hsdev->phy = devm_phy_optional_get(hsdev->dev, "sata-phy");
1265 	if (IS_ERR(hsdev->phy)) {
1266 		err = PTR_ERR(hsdev->phy);
1267 		hsdev->phy = NULL;
1268 		goto error_out;
1269 	}
1270 
1271 	err = phy_init(hsdev->phy);
1272 	if (err)
1273 		goto error_out;
1274 
1275 	/*
1276 	 * Now, register with libATA core, this will also initiate the
1277 	 * device discovery process, invoking our port_start() handler &
1278 	 * error_handler() to execute a dummy Softreset EH session
1279 	 */
1280 	err = ata_host_activate(host, irq, sata_dwc_isr, 0, &sata_dwc_sht);
1281 	if (err)
1282 		dev_err(&ofdev->dev, "failed to activate host");
1283 
1284 	return 0;
1285 
1286 error_out:
1287 	phy_exit(hsdev->phy);
1288 	return err;
1289 }
1290 
1291 static int sata_dwc_remove(struct platform_device *ofdev)
1292 {
1293 	struct device *dev = &ofdev->dev;
1294 	struct ata_host *host = dev_get_drvdata(dev);
1295 	struct sata_dwc_device *hsdev = host->private_data;
1296 
1297 	ata_host_detach(host);
1298 
1299 	phy_exit(hsdev->phy);
1300 
1301 #ifdef CONFIG_SATA_DWC_OLD_DMA
1302 	/* Free SATA DMA resources */
1303 	sata_dwc_dma_exit_old(hsdev);
1304 #endif
1305 
1306 	dev_dbg(&ofdev->dev, "done\n");
1307 	return 0;
1308 }
1309 
1310 static const struct of_device_id sata_dwc_match[] = {
1311 	{ .compatible = "amcc,sata-460ex", },
1312 	{}
1313 };
1314 MODULE_DEVICE_TABLE(of, sata_dwc_match);
1315 
1316 static struct platform_driver sata_dwc_driver = {
1317 	.driver = {
1318 		.name = DRV_NAME,
1319 		.of_match_table = sata_dwc_match,
1320 	},
1321 	.probe = sata_dwc_probe,
1322 	.remove = sata_dwc_remove,
1323 };
1324 
1325 module_platform_driver(sata_dwc_driver);
1326 
1327 MODULE_LICENSE("GPL");
1328 MODULE_AUTHOR("Mark Miesfeld <mmiesfeld@amcc.com>");
1329 MODULE_DESCRIPTION("DesignWare Cores SATA controller low level driver");
1330 MODULE_VERSION(DRV_VERSION);
1331