xref: /linux/drivers/ata/sata_dwc_460ex.c (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
1 /*
2  * drivers/ata/sata_dwc_460ex.c
3  *
4  * Synopsys DesignWare Cores (DWC) SATA host driver
5  *
6  * Author: Mark Miesfeld <mmiesfeld@amcc.com>
7  *
8  * Ported from 2.6.19.2 to 2.6.25/26 by Stefan Roese <sr@denx.de>
9  * Copyright 2008 DENX Software Engineering
10  *
11  * Based on versions provided by AMCC and Synopsys which are:
12  *          Copyright 2006 Applied Micro Circuits Corporation
13  *          COPYRIGHT (C) 2005  SYNOPSYS, INC.  ALL RIGHTS RESERVED
14  *
15  * This program is free software; you can redistribute  it and/or modify it
16  * under  the terms of  the GNU General  Public License as published by the
17  * Free Software Foundation;  either version 2 of the  License, or (at your
18  * option) any later version.
19  */
20 
21 #ifdef CONFIG_SATA_DWC_DEBUG
22 #define DEBUG
23 #endif
24 
25 #ifdef CONFIG_SATA_DWC_VDEBUG
26 #define VERBOSE_DEBUG
27 #define DEBUG_NCQ
28 #endif
29 
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/device.h>
33 #include <linux/of_address.h>
34 #include <linux/of_irq.h>
35 #include <linux/of_platform.h>
36 #include <linux/platform_device.h>
37 #include <linux/libata.h>
38 #include <linux/slab.h>
39 
40 #include "libata.h"
41 
42 #include <scsi/scsi_host.h>
43 #include <scsi/scsi_cmnd.h>
44 
45 /* Supported DMA engine drivers */
46 #include <linux/platform_data/dma-dw.h>
47 #include <linux/dma/dw.h>
48 
49 /* These two are defined in "libata.h" */
50 #undef	DRV_NAME
51 #undef	DRV_VERSION
52 
53 #define DRV_NAME        "sata-dwc"
54 #define DRV_VERSION     "1.3"
55 
56 #ifndef out_le32
57 #define out_le32(a, v)	__raw_writel(__cpu_to_le32(v), (void __iomem *)(a))
58 #endif
59 
60 #ifndef in_le32
61 #define in_le32(a)	__le32_to_cpu(__raw_readl((void __iomem *)(a)))
62 #endif
63 
64 #ifndef NO_IRQ
65 #define NO_IRQ		0
66 #endif
67 
68 #define AHB_DMA_BRST_DFLT	64	/* 16 data items burst length*/
69 
70 enum {
71 	SATA_DWC_MAX_PORTS = 1,
72 
73 	SATA_DWC_SCR_OFFSET = 0x24,
74 	SATA_DWC_REG_OFFSET = 0x64,
75 };
76 
77 /* DWC SATA Registers */
78 struct sata_dwc_regs {
79 	u32 fptagr;		/* 1st party DMA tag */
80 	u32 fpbor;		/* 1st party DMA buffer offset */
81 	u32 fptcr;		/* 1st party DMA Xfr count */
82 	u32 dmacr;		/* DMA Control */
83 	u32 dbtsr;		/* DMA Burst Transac size */
84 	u32 intpr;		/* Interrupt Pending */
85 	u32 intmr;		/* Interrupt Mask */
86 	u32 errmr;		/* Error Mask */
87 	u32 llcr;		/* Link Layer Control */
88 	u32 phycr;		/* PHY Control */
89 	u32 physr;		/* PHY Status */
90 	u32 rxbistpd;		/* Recvd BIST pattern def register */
91 	u32 rxbistpd1;		/* Recvd BIST data dword1 */
92 	u32 rxbistpd2;		/* Recvd BIST pattern data dword2 */
93 	u32 txbistpd;		/* Trans BIST pattern def register */
94 	u32 txbistpd1;		/* Trans BIST data dword1 */
95 	u32 txbistpd2;		/* Trans BIST data dword2 */
96 	u32 bistcr;		/* BIST Control Register */
97 	u32 bistfctr;		/* BIST FIS Count Register */
98 	u32 bistsr;		/* BIST Status Register */
99 	u32 bistdecr;		/* BIST Dword Error count register */
100 	u32 res[15];		/* Reserved locations */
101 	u32 testr;		/* Test Register */
102 	u32 versionr;		/* Version Register */
103 	u32 idr;		/* ID Register */
104 	u32 unimpl[192];	/* Unimplemented */
105 	u32 dmadr[256];	/* FIFO Locations in DMA Mode */
106 };
107 
108 enum {
109 	SCR_SCONTROL_DET_ENABLE	=	0x00000001,
110 	SCR_SSTATUS_DET_PRESENT	=	0x00000001,
111 	SCR_SERROR_DIAG_X	=	0x04000000,
112 /* DWC SATA Register Operations */
113 	SATA_DWC_TXFIFO_DEPTH	=	0x01FF,
114 	SATA_DWC_RXFIFO_DEPTH	=	0x01FF,
115 	SATA_DWC_DMACR_TMOD_TXCHEN =	0x00000004,
116 	SATA_DWC_DMACR_TXCHEN	= (0x00000001 | SATA_DWC_DMACR_TMOD_TXCHEN),
117 	SATA_DWC_DMACR_RXCHEN	= (0x00000002 | SATA_DWC_DMACR_TMOD_TXCHEN),
118 	SATA_DWC_DMACR_TXRXCH_CLEAR =	SATA_DWC_DMACR_TMOD_TXCHEN,
119 	SATA_DWC_INTPR_DMAT	=	0x00000001,
120 	SATA_DWC_INTPR_NEWFP	=	0x00000002,
121 	SATA_DWC_INTPR_PMABRT	=	0x00000004,
122 	SATA_DWC_INTPR_ERR	=	0x00000008,
123 	SATA_DWC_INTPR_NEWBIST	=	0x00000010,
124 	SATA_DWC_INTPR_IPF	=	0x10000000,
125 	SATA_DWC_INTMR_DMATM	=	0x00000001,
126 	SATA_DWC_INTMR_NEWFPM	=	0x00000002,
127 	SATA_DWC_INTMR_PMABRTM	=	0x00000004,
128 	SATA_DWC_INTMR_ERRM	=	0x00000008,
129 	SATA_DWC_INTMR_NEWBISTM	=	0x00000010,
130 	SATA_DWC_LLCR_SCRAMEN	=	0x00000001,
131 	SATA_DWC_LLCR_DESCRAMEN	=	0x00000002,
132 	SATA_DWC_LLCR_RPDEN	=	0x00000004,
133 /* This is all error bits, zero's are reserved fields. */
134 	SATA_DWC_SERROR_ERR_BITS =	0x0FFF0F03
135 };
136 
137 #define SATA_DWC_SCR0_SPD_GET(v)	(((v) >> 4) & 0x0000000F)
138 #define SATA_DWC_DMACR_TX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_TXCHEN) |\
139 						 SATA_DWC_DMACR_TMOD_TXCHEN)
140 #define SATA_DWC_DMACR_RX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_RXCHEN) |\
141 						 SATA_DWC_DMACR_TMOD_TXCHEN)
142 #define SATA_DWC_DBTSR_MWR(size)	(((size)/4) & SATA_DWC_TXFIFO_DEPTH)
143 #define SATA_DWC_DBTSR_MRD(size)	((((size)/4) & SATA_DWC_RXFIFO_DEPTH)\
144 						 << 16)
145 struct sata_dwc_device {
146 	struct device		*dev;		/* generic device struct */
147 	struct ata_probe_ent	*pe;		/* ptr to probe-ent */
148 	struct ata_host		*host;
149 	u8 __iomem		*reg_base;
150 	struct sata_dwc_regs	*sata_dwc_regs;	/* DW Synopsys SATA specific */
151 	struct dw_dma_chip	*dma;
152 };
153 
154 #define SATA_DWC_QCMD_MAX	32
155 
156 struct sata_dwc_device_port {
157 	struct sata_dwc_device	*hsdev;
158 	int			cmd_issued[SATA_DWC_QCMD_MAX];
159 	int			dma_pending[SATA_DWC_QCMD_MAX];
160 
161 	/* DMA info */
162 	struct dw_dma_slave		*dws;
163 	struct dma_chan			*chan;
164 	struct dma_async_tx_descriptor	*desc[SATA_DWC_QCMD_MAX];
165 	u32				dma_interrupt_count;
166 };
167 
168 /*
169  * Commonly used DWC SATA driver Macros
170  */
171 #define HSDEV_FROM_HOST(host)  ((struct sata_dwc_device *)\
172 					(host)->private_data)
173 #define HSDEV_FROM_AP(ap)  ((struct sata_dwc_device *)\
174 					(ap)->host->private_data)
175 #define HSDEVP_FROM_AP(ap)   ((struct sata_dwc_device_port *)\
176 					(ap)->private_data)
177 #define HSDEV_FROM_QC(qc)	((struct sata_dwc_device *)\
178 					(qc)->ap->host->private_data)
179 #define HSDEV_FROM_HSDEVP(p)	((struct sata_dwc_device *)\
180 						(hsdevp)->hsdev)
181 
182 enum {
183 	SATA_DWC_CMD_ISSUED_NOT		= 0,
184 	SATA_DWC_CMD_ISSUED_PEND	= 1,
185 	SATA_DWC_CMD_ISSUED_EXEC	= 2,
186 	SATA_DWC_CMD_ISSUED_NODATA	= 3,
187 
188 	SATA_DWC_DMA_PENDING_NONE	= 0,
189 	SATA_DWC_DMA_PENDING_TX		= 1,
190 	SATA_DWC_DMA_PENDING_RX		= 2,
191 };
192 
193 struct sata_dwc_host_priv {
194 	void	__iomem	 *scr_addr_sstatus;
195 	u32	sata_dwc_sactive_issued ;
196 	u32	sata_dwc_sactive_queued ;
197 };
198 
199 static struct sata_dwc_host_priv host_pvt;
200 
201 static struct dw_dma_slave sata_dwc_dma_dws = {
202 	.src_id = 0,
203 	.dst_id = 0,
204 	.src_master = 0,
205 	.dst_master = 1,
206 };
207 
208 /*
209  * Prototypes
210  */
211 static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag);
212 static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
213 				u32 check_status);
214 static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status);
215 static void sata_dwc_port_stop(struct ata_port *ap);
216 static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag);
217 
218 static const char *get_prot_descript(u8 protocol)
219 {
220 	switch ((enum ata_tf_protocols)protocol) {
221 	case ATA_PROT_NODATA:
222 		return "ATA no data";
223 	case ATA_PROT_PIO:
224 		return "ATA PIO";
225 	case ATA_PROT_DMA:
226 		return "ATA DMA";
227 	case ATA_PROT_NCQ:
228 		return "ATA NCQ";
229 	case ATAPI_PROT_NODATA:
230 		return "ATAPI no data";
231 	case ATAPI_PROT_PIO:
232 		return "ATAPI PIO";
233 	case ATAPI_PROT_DMA:
234 		return "ATAPI DMA";
235 	default:
236 		return "unknown";
237 	}
238 }
239 
240 static const char *get_dma_dir_descript(int dma_dir)
241 {
242 	switch ((enum dma_data_direction)dma_dir) {
243 	case DMA_BIDIRECTIONAL:
244 		return "bidirectional";
245 	case DMA_TO_DEVICE:
246 		return "to device";
247 	case DMA_FROM_DEVICE:
248 		return "from device";
249 	default:
250 		return "none";
251 	}
252 }
253 
254 static void sata_dwc_tf_dump(struct ata_port *ap, struct ata_taskfile *tf)
255 {
256 	dev_vdbg(ap->dev,
257 		"taskfile cmd: 0x%02x protocol: %s flags: 0x%lx device: %x\n",
258 		tf->command, get_prot_descript(tf->protocol), tf->flags,
259 		tf->device);
260 	dev_vdbg(ap->dev,
261 		"feature: 0x%02x nsect: 0x%x lbal: 0x%x lbam: 0x%x lbah: 0x%x\n",
262 		tf->feature, tf->nsect, tf->lbal, tf->lbam, tf->lbah);
263 	dev_vdbg(ap->dev,
264 		"hob_feature: 0x%02x hob_nsect: 0x%x hob_lbal: 0x%x hob_lbam: 0x%x hob_lbah: 0x%x\n",
265 		tf->hob_feature, tf->hob_nsect, tf->hob_lbal, tf->hob_lbam,
266 		tf->hob_lbah);
267 }
268 
269 static void dma_dwc_xfer_done(void *hsdev_instance)
270 {
271 	unsigned long flags;
272 	struct sata_dwc_device *hsdev = hsdev_instance;
273 	struct ata_host *host = (struct ata_host *)hsdev->host;
274 	struct ata_port *ap;
275 	struct sata_dwc_device_port *hsdevp;
276 	u8 tag = 0;
277 	unsigned int port = 0;
278 
279 	spin_lock_irqsave(&host->lock, flags);
280 	ap = host->ports[port];
281 	hsdevp = HSDEVP_FROM_AP(ap);
282 	tag = ap->link.active_tag;
283 
284 	/*
285 	 * Each DMA command produces 2 interrupts.  Only
286 	 * complete the command after both interrupts have been
287 	 * seen. (See sata_dwc_isr())
288 	 */
289 	hsdevp->dma_interrupt_count++;
290 	sata_dwc_clear_dmacr(hsdevp, tag);
291 
292 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_NONE) {
293 		dev_err(ap->dev, "DMA not pending tag=0x%02x pending=%d\n",
294 			tag, hsdevp->dma_pending[tag]);
295 	}
296 
297 	if ((hsdevp->dma_interrupt_count % 2) == 0)
298 		sata_dwc_dma_xfer_complete(ap, 1);
299 
300 	spin_unlock_irqrestore(&host->lock, flags);
301 }
302 
303 static struct dma_async_tx_descriptor *dma_dwc_xfer_setup(struct ata_queued_cmd *qc)
304 {
305 	struct ata_port *ap = qc->ap;
306 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
307 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
308 	dma_addr_t addr = (dma_addr_t)&hsdev->sata_dwc_regs->dmadr;
309 	struct dma_slave_config sconf;
310 	struct dma_async_tx_descriptor *desc;
311 
312 	if (qc->dma_dir == DMA_DEV_TO_MEM) {
313 		sconf.src_addr = addr;
314 		sconf.device_fc = true;
315 	} else {	/* DMA_MEM_TO_DEV */
316 		sconf.dst_addr = addr;
317 		sconf.device_fc = false;
318 	}
319 
320 	sconf.direction = qc->dma_dir;
321 	sconf.src_maxburst = AHB_DMA_BRST_DFLT;
322 	sconf.dst_maxburst = AHB_DMA_BRST_DFLT;
323 	sconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
324 	sconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
325 
326 	dmaengine_slave_config(hsdevp->chan, &sconf);
327 
328 	/* Convert SG list to linked list of items (LLIs) for AHB DMA */
329 	desc = dmaengine_prep_slave_sg(hsdevp->chan, qc->sg, qc->n_elem,
330 				       qc->dma_dir,
331 				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
332 
333 	if (!desc)
334 		return NULL;
335 
336 	desc->callback = dma_dwc_xfer_done;
337 	desc->callback_param = hsdev;
338 
339 	dev_dbg(hsdev->dev, "%s sg: 0x%p, count: %d addr: %pad\n",
340 		__func__, qc->sg, qc->n_elem, &addr);
341 
342 	return desc;
343 }
344 
345 static int sata_dwc_scr_read(struct ata_link *link, unsigned int scr, u32 *val)
346 {
347 	if (scr > SCR_NOTIFICATION) {
348 		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
349 			__func__, scr);
350 		return -EINVAL;
351 	}
352 
353 	*val = in_le32(link->ap->ioaddr.scr_addr + (scr * 4));
354 	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=val=0x%08x\n",
355 		__func__, link->ap->print_id, scr, *val);
356 
357 	return 0;
358 }
359 
360 static int sata_dwc_scr_write(struct ata_link *link, unsigned int scr, u32 val)
361 {
362 	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=val=0x%08x\n",
363 		__func__, link->ap->print_id, scr, val);
364 	if (scr > SCR_NOTIFICATION) {
365 		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
366 			 __func__, scr);
367 		return -EINVAL;
368 	}
369 	out_le32(link->ap->ioaddr.scr_addr + (scr * 4), val);
370 
371 	return 0;
372 }
373 
374 static u32 core_scr_read(unsigned int scr)
375 {
376 	return in_le32(host_pvt.scr_addr_sstatus + (scr * 4));
377 }
378 
379 static void core_scr_write(unsigned int scr, u32 val)
380 {
381 	out_le32(host_pvt.scr_addr_sstatus + (scr * 4), val);
382 }
383 
384 static void clear_serror(void)
385 {
386 	u32 val;
387 	val = core_scr_read(SCR_ERROR);
388 	core_scr_write(SCR_ERROR, val);
389 }
390 
391 static void clear_interrupt_bit(struct sata_dwc_device *hsdev, u32 bit)
392 {
393 	out_le32(&hsdev->sata_dwc_regs->intpr,
394 		 in_le32(&hsdev->sata_dwc_regs->intpr));
395 }
396 
397 static u32 qcmd_tag_to_mask(u8 tag)
398 {
399 	return 0x00000001 << (tag & 0x1f);
400 }
401 
402 /* See ahci.c */
403 static void sata_dwc_error_intr(struct ata_port *ap,
404 				struct sata_dwc_device *hsdev, uint intpr)
405 {
406 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
407 	struct ata_eh_info *ehi = &ap->link.eh_info;
408 	unsigned int err_mask = 0, action = 0;
409 	struct ata_queued_cmd *qc;
410 	u32 serror;
411 	u8 status, tag;
412 
413 	ata_ehi_clear_desc(ehi);
414 
415 	serror = core_scr_read(SCR_ERROR);
416 	status = ap->ops->sff_check_status(ap);
417 
418 	tag = ap->link.active_tag;
419 
420 	dev_err(ap->dev,
421 		"%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x dma_intp=%d pending=%d issued=%d",
422 		__func__, serror, intpr, status, hsdevp->dma_interrupt_count,
423 		hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag]);
424 
425 	/* Clear error register and interrupt bit */
426 	clear_serror();
427 	clear_interrupt_bit(hsdev, SATA_DWC_INTPR_ERR);
428 
429 	/* This is the only error happening now.  TODO check for exact error */
430 
431 	err_mask |= AC_ERR_HOST_BUS;
432 	action |= ATA_EH_RESET;
433 
434 	/* Pass this on to EH */
435 	ehi->serror |= serror;
436 	ehi->action |= action;
437 
438 	qc = ata_qc_from_tag(ap, tag);
439 	if (qc)
440 		qc->err_mask |= err_mask;
441 	else
442 		ehi->err_mask |= err_mask;
443 
444 	ata_port_abort(ap);
445 }
446 
447 /*
448  * Function : sata_dwc_isr
449  * arguments : irq, void *dev_instance, struct pt_regs *regs
450  * Return value : irqreturn_t - status of IRQ
451  * This Interrupt handler called via port ops registered function.
452  * .irq_handler = sata_dwc_isr
453  */
454 static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)
455 {
456 	struct ata_host *host = (struct ata_host *)dev_instance;
457 	struct sata_dwc_device *hsdev = HSDEV_FROM_HOST(host);
458 	struct ata_port *ap;
459 	struct ata_queued_cmd *qc;
460 	unsigned long flags;
461 	u8 status, tag;
462 	int handled, num_processed, port = 0;
463 	uint intpr, sactive, sactive2, tag_mask;
464 	struct sata_dwc_device_port *hsdevp;
465 	host_pvt.sata_dwc_sactive_issued = 0;
466 
467 	spin_lock_irqsave(&host->lock, flags);
468 
469 	/* Read the interrupt register */
470 	intpr = in_le32(&hsdev->sata_dwc_regs->intpr);
471 
472 	ap = host->ports[port];
473 	hsdevp = HSDEVP_FROM_AP(ap);
474 
475 	dev_dbg(ap->dev, "%s intpr=0x%08x active_tag=%d\n", __func__, intpr,
476 		ap->link.active_tag);
477 
478 	/* Check for error interrupt */
479 	if (intpr & SATA_DWC_INTPR_ERR) {
480 		sata_dwc_error_intr(ap, hsdev, intpr);
481 		handled = 1;
482 		goto DONE;
483 	}
484 
485 	/* Check for DMA SETUP FIS (FP DMA) interrupt */
486 	if (intpr & SATA_DWC_INTPR_NEWFP) {
487 		clear_interrupt_bit(hsdev, SATA_DWC_INTPR_NEWFP);
488 
489 		tag = (u8)(in_le32(&hsdev->sata_dwc_regs->fptagr));
490 		dev_dbg(ap->dev, "%s: NEWFP tag=%d\n", __func__, tag);
491 		if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_PEND)
492 			dev_warn(ap->dev, "CMD tag=%d not pending?\n", tag);
493 
494 		host_pvt.sata_dwc_sactive_issued |= qcmd_tag_to_mask(tag);
495 
496 		qc = ata_qc_from_tag(ap, tag);
497 		/*
498 		 * Start FP DMA for NCQ command.  At this point the tag is the
499 		 * active tag.  It is the tag that matches the command about to
500 		 * be completed.
501 		 */
502 		qc->ap->link.active_tag = tag;
503 		sata_dwc_bmdma_start_by_tag(qc, tag);
504 
505 		handled = 1;
506 		goto DONE;
507 	}
508 	sactive = core_scr_read(SCR_ACTIVE);
509 	tag_mask = (host_pvt.sata_dwc_sactive_issued | sactive) ^ sactive;
510 
511 	/* If no sactive issued and tag_mask is zero then this is not NCQ */
512 	if (host_pvt.sata_dwc_sactive_issued == 0 && tag_mask == 0) {
513 		if (ap->link.active_tag == ATA_TAG_POISON)
514 			tag = 0;
515 		else
516 			tag = ap->link.active_tag;
517 		qc = ata_qc_from_tag(ap, tag);
518 
519 		/* DEV interrupt w/ no active qc? */
520 		if (unlikely(!qc || (qc->tf.flags & ATA_TFLAG_POLLING))) {
521 			dev_err(ap->dev,
522 				"%s interrupt with no active qc qc=%p\n",
523 				__func__, qc);
524 			ap->ops->sff_check_status(ap);
525 			handled = 1;
526 			goto DONE;
527 		}
528 		status = ap->ops->sff_check_status(ap);
529 
530 		qc->ap->link.active_tag = tag;
531 		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
532 
533 		if (status & ATA_ERR) {
534 			dev_dbg(ap->dev, "interrupt ATA_ERR (0x%x)\n", status);
535 			sata_dwc_qc_complete(ap, qc, 1);
536 			handled = 1;
537 			goto DONE;
538 		}
539 
540 		dev_dbg(ap->dev, "%s non-NCQ cmd interrupt, protocol: %s\n",
541 			__func__, get_prot_descript(qc->tf.protocol));
542 DRVSTILLBUSY:
543 		if (ata_is_dma(qc->tf.protocol)) {
544 			/*
545 			 * Each DMA transaction produces 2 interrupts. The DMAC
546 			 * transfer complete interrupt and the SATA controller
547 			 * operation done interrupt. The command should be
548 			 * completed only after both interrupts are seen.
549 			 */
550 			hsdevp->dma_interrupt_count++;
551 			if (hsdevp->dma_pending[tag] == \
552 					SATA_DWC_DMA_PENDING_NONE) {
553 				dev_err(ap->dev,
554 					"%s: DMA not pending intpr=0x%08x status=0x%08x pending=%d\n",
555 					__func__, intpr, status,
556 					hsdevp->dma_pending[tag]);
557 			}
558 
559 			if ((hsdevp->dma_interrupt_count % 2) == 0)
560 				sata_dwc_dma_xfer_complete(ap, 1);
561 		} else if (ata_is_pio(qc->tf.protocol)) {
562 			ata_sff_hsm_move(ap, qc, status, 0);
563 			handled = 1;
564 			goto DONE;
565 		} else {
566 			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
567 				goto DRVSTILLBUSY;
568 		}
569 
570 		handled = 1;
571 		goto DONE;
572 	}
573 
574 	/*
575 	 * This is a NCQ command. At this point we need to figure out for which
576 	 * tags we have gotten a completion interrupt.  One interrupt may serve
577 	 * as completion for more than one operation when commands are queued
578 	 * (NCQ).  We need to process each completed command.
579 	 */
580 
581 	 /* process completed commands */
582 	sactive = core_scr_read(SCR_ACTIVE);
583 	tag_mask = (host_pvt.sata_dwc_sactive_issued | sactive) ^ sactive;
584 
585 	if (sactive != 0 || (host_pvt.sata_dwc_sactive_issued) > 1 || \
586 							tag_mask > 1) {
587 		dev_dbg(ap->dev,
588 			"%s NCQ:sactive=0x%08x  sactive_issued=0x%08x tag_mask=0x%08x\n",
589 			__func__, sactive, host_pvt.sata_dwc_sactive_issued,
590 			tag_mask);
591 	}
592 
593 	if ((tag_mask | (host_pvt.sata_dwc_sactive_issued)) != \
594 					(host_pvt.sata_dwc_sactive_issued)) {
595 		dev_warn(ap->dev,
596 			 "Bad tag mask?  sactive=0x%08x (host_pvt.sata_dwc_sactive_issued)=0x%08x  tag_mask=0x%08x\n",
597 			 sactive, host_pvt.sata_dwc_sactive_issued, tag_mask);
598 	}
599 
600 	/* read just to clear ... not bad if currently still busy */
601 	status = ap->ops->sff_check_status(ap);
602 	dev_dbg(ap->dev, "%s ATA status register=0x%x\n", __func__, status);
603 
604 	tag = 0;
605 	num_processed = 0;
606 	while (tag_mask) {
607 		num_processed++;
608 		while (!(tag_mask & 0x00000001)) {
609 			tag++;
610 			tag_mask <<= 1;
611 		}
612 
613 		tag_mask &= (~0x00000001);
614 		qc = ata_qc_from_tag(ap, tag);
615 
616 		/* To be picked up by completion functions */
617 		qc->ap->link.active_tag = tag;
618 		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
619 
620 		/* Let libata/scsi layers handle error */
621 		if (status & ATA_ERR) {
622 			dev_dbg(ap->dev, "%s ATA_ERR (0x%x)\n", __func__,
623 				status);
624 			sata_dwc_qc_complete(ap, qc, 1);
625 			handled = 1;
626 			goto DONE;
627 		}
628 
629 		/* Process completed command */
630 		dev_dbg(ap->dev, "%s NCQ command, protocol: %s\n", __func__,
631 			get_prot_descript(qc->tf.protocol));
632 		if (ata_is_dma(qc->tf.protocol)) {
633 			hsdevp->dma_interrupt_count++;
634 			if (hsdevp->dma_pending[tag] == \
635 					SATA_DWC_DMA_PENDING_NONE)
636 				dev_warn(ap->dev, "%s: DMA not pending?\n",
637 					__func__);
638 			if ((hsdevp->dma_interrupt_count % 2) == 0)
639 				sata_dwc_dma_xfer_complete(ap, 1);
640 		} else {
641 			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
642 				goto STILLBUSY;
643 		}
644 		continue;
645 
646 STILLBUSY:
647 		ap->stats.idle_irq++;
648 		dev_warn(ap->dev, "STILL BUSY IRQ ata%d: irq trap\n",
649 			ap->print_id);
650 	} /* while tag_mask */
651 
652 	/*
653 	 * Check to see if any commands completed while we were processing our
654 	 * initial set of completed commands (read status clears interrupts,
655 	 * so we might miss a completed command interrupt if one came in while
656 	 * we were processing --we read status as part of processing a completed
657 	 * command).
658 	 */
659 	sactive2 = core_scr_read(SCR_ACTIVE);
660 	if (sactive2 != sactive) {
661 		dev_dbg(ap->dev,
662 			"More completed - sactive=0x%x sactive2=0x%x\n",
663 			sactive, sactive2);
664 	}
665 	handled = 1;
666 
667 DONE:
668 	spin_unlock_irqrestore(&host->lock, flags);
669 	return IRQ_RETVAL(handled);
670 }
671 
672 static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag)
673 {
674 	struct sata_dwc_device *hsdev = HSDEV_FROM_HSDEVP(hsdevp);
675 
676 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX) {
677 		out_le32(&(hsdev->sata_dwc_regs->dmacr),
678 			 SATA_DWC_DMACR_RX_CLEAR(
679 				 in_le32(&(hsdev->sata_dwc_regs->dmacr))));
680 	} else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX) {
681 		out_le32(&(hsdev->sata_dwc_regs->dmacr),
682 			 SATA_DWC_DMACR_TX_CLEAR(
683 				 in_le32(&(hsdev->sata_dwc_regs->dmacr))));
684 	} else {
685 		/*
686 		 * This should not happen, it indicates the driver is out of
687 		 * sync.  If it does happen, clear dmacr anyway.
688 		 */
689 		dev_err(hsdev->dev,
690 			"%s DMA protocol RX and TX DMA not pending tag=0x%02x pending=%d dmacr: 0x%08x\n",
691 			__func__, tag, hsdevp->dma_pending[tag],
692 			in_le32(&hsdev->sata_dwc_regs->dmacr));
693 		out_le32(&(hsdev->sata_dwc_regs->dmacr),
694 			SATA_DWC_DMACR_TXRXCH_CLEAR);
695 	}
696 }
697 
698 static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status)
699 {
700 	struct ata_queued_cmd *qc;
701 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
702 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
703 	u8 tag = 0;
704 
705 	tag = ap->link.active_tag;
706 	qc = ata_qc_from_tag(ap, tag);
707 	if (!qc) {
708 		dev_err(ap->dev, "failed to get qc");
709 		return;
710 	}
711 
712 #ifdef DEBUG_NCQ
713 	if (tag > 0) {
714 		dev_info(ap->dev,
715 			 "%s tag=%u cmd=0x%02x dma dir=%s proto=%s dmacr=0x%08x\n",
716 			 __func__, qc->tag, qc->tf.command,
717 			 get_dma_dir_descript(qc->dma_dir),
718 			 get_prot_descript(qc->tf.protocol),
719 			 in_le32(&(hsdev->sata_dwc_regs->dmacr)));
720 	}
721 #endif
722 
723 	if (ata_is_dma(qc->tf.protocol)) {
724 		if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_NONE) {
725 			dev_err(ap->dev,
726 				"%s DMA protocol RX and TX DMA not pending dmacr: 0x%08x\n",
727 				__func__,
728 				in_le32(&(hsdev->sata_dwc_regs->dmacr)));
729 		}
730 
731 		hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_NONE;
732 		sata_dwc_qc_complete(ap, qc, check_status);
733 		ap->link.active_tag = ATA_TAG_POISON;
734 	} else {
735 		sata_dwc_qc_complete(ap, qc, check_status);
736 	}
737 }
738 
739 static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
740 				u32 check_status)
741 {
742 	u8 status = 0;
743 	u32 mask = 0x0;
744 	u8 tag = qc->tag;
745 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
746 	host_pvt.sata_dwc_sactive_queued = 0;
747 	dev_dbg(ap->dev, "%s checkstatus? %x\n", __func__, check_status);
748 
749 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX)
750 		dev_err(ap->dev, "TX DMA PENDING\n");
751 	else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX)
752 		dev_err(ap->dev, "RX DMA PENDING\n");
753 	dev_dbg(ap->dev,
754 		"QC complete cmd=0x%02x status=0x%02x ata%u: protocol=%d\n",
755 		qc->tf.command, status, ap->print_id, qc->tf.protocol);
756 
757 	/* clear active bit */
758 	mask = (~(qcmd_tag_to_mask(tag)));
759 	host_pvt.sata_dwc_sactive_queued = (host_pvt.sata_dwc_sactive_queued) \
760 						& mask;
761 	host_pvt.sata_dwc_sactive_issued = (host_pvt.sata_dwc_sactive_issued) \
762 						& mask;
763 	ata_qc_complete(qc);
764 	return 0;
765 }
766 
767 static void sata_dwc_enable_interrupts(struct sata_dwc_device *hsdev)
768 {
769 	/* Enable selective interrupts by setting the interrupt maskregister*/
770 	out_le32(&hsdev->sata_dwc_regs->intmr,
771 		 SATA_DWC_INTMR_ERRM |
772 		 SATA_DWC_INTMR_NEWFPM |
773 		 SATA_DWC_INTMR_PMABRTM |
774 		 SATA_DWC_INTMR_DMATM);
775 	/*
776 	 * Unmask the error bits that should trigger an error interrupt by
777 	 * setting the error mask register.
778 	 */
779 	out_le32(&hsdev->sata_dwc_regs->errmr, SATA_DWC_SERROR_ERR_BITS);
780 
781 	dev_dbg(hsdev->dev, "%s: INTMR = 0x%08x, ERRMR = 0x%08x\n",
782 		 __func__, in_le32(&hsdev->sata_dwc_regs->intmr),
783 		in_le32(&hsdev->sata_dwc_regs->errmr));
784 }
785 
786 static bool sata_dwc_dma_filter(struct dma_chan *chan, void *param)
787 {
788 	struct sata_dwc_device_port *hsdevp = param;
789 	struct dw_dma_slave *dws = hsdevp->dws;
790 
791 	if (dws->dma_dev != chan->device->dev)
792 		return false;
793 
794 	chan->private = dws;
795 	return true;
796 }
797 
798 static void sata_dwc_setup_port(struct ata_ioports *port, unsigned long base)
799 {
800 	port->cmd_addr = (void __iomem *)base + 0x00;
801 	port->data_addr = (void __iomem *)base + 0x00;
802 
803 	port->error_addr = (void __iomem *)base + 0x04;
804 	port->feature_addr = (void __iomem *)base + 0x04;
805 
806 	port->nsect_addr = (void __iomem *)base + 0x08;
807 
808 	port->lbal_addr = (void __iomem *)base + 0x0c;
809 	port->lbam_addr = (void __iomem *)base + 0x10;
810 	port->lbah_addr = (void __iomem *)base + 0x14;
811 
812 	port->device_addr = (void __iomem *)base + 0x18;
813 	port->command_addr = (void __iomem *)base + 0x1c;
814 	port->status_addr = (void __iomem *)base + 0x1c;
815 
816 	port->altstatus_addr = (void __iomem *)base + 0x20;
817 	port->ctl_addr = (void __iomem *)base + 0x20;
818 }
819 
820 /*
821  * Function : sata_dwc_port_start
822  * arguments : struct ata_ioports *port
823  * Return value : returns 0 if success, error code otherwise
824  * This function allocates the scatter gather LLI table for AHB DMA
825  */
826 static int sata_dwc_port_start(struct ata_port *ap)
827 {
828 	int err = 0;
829 	struct sata_dwc_device *hsdev;
830 	struct sata_dwc_device_port *hsdevp = NULL;
831 	struct device *pdev;
832 	dma_cap_mask_t mask;
833 	int i;
834 
835 	hsdev = HSDEV_FROM_AP(ap);
836 
837 	dev_dbg(ap->dev, "%s: port_no=%d\n", __func__, ap->port_no);
838 
839 	hsdev->host = ap->host;
840 	pdev = ap->host->dev;
841 	if (!pdev) {
842 		dev_err(ap->dev, "%s: no ap->host->dev\n", __func__);
843 		err = -ENODEV;
844 		goto CLEANUP;
845 	}
846 
847 	/* Allocate Port Struct */
848 	hsdevp = kzalloc(sizeof(*hsdevp), GFP_KERNEL);
849 	if (!hsdevp) {
850 		dev_err(ap->dev, "%s: kmalloc failed for hsdevp\n", __func__);
851 		err = -ENOMEM;
852 		goto CLEANUP;
853 	}
854 	hsdevp->hsdev = hsdev;
855 
856 	hsdevp->dws = &sata_dwc_dma_dws;
857 	hsdevp->dws->dma_dev = hsdev->dev;
858 
859 	dma_cap_zero(mask);
860 	dma_cap_set(DMA_SLAVE, mask);
861 
862 	/* Acquire DMA channel */
863 	hsdevp->chan = dma_request_channel(mask, sata_dwc_dma_filter, hsdevp);
864 	if (!hsdevp->chan) {
865 		dev_err(hsdev->dev, "%s: dma channel unavailable\n",
866 			 __func__);
867 		err = -EAGAIN;
868 		goto CLEANUP_ALLOC;
869 	}
870 
871 	for (i = 0; i < SATA_DWC_QCMD_MAX; i++)
872 		hsdevp->cmd_issued[i] = SATA_DWC_CMD_ISSUED_NOT;
873 
874 	ap->bmdma_prd = NULL;	/* set these so libata doesn't use them */
875 	ap->bmdma_prd_dma = 0;
876 
877 	if (ap->port_no == 0)  {
878 		dev_dbg(ap->dev, "%s: clearing TXCHEN, RXCHEN in DMAC\n",
879 			__func__);
880 		out_le32(&hsdev->sata_dwc_regs->dmacr,
881 			 SATA_DWC_DMACR_TXRXCH_CLEAR);
882 
883 		dev_dbg(ap->dev, "%s: setting burst size in DBTSR\n",
884 			 __func__);
885 		out_le32(&hsdev->sata_dwc_regs->dbtsr,
886 			 (SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
887 			  SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT)));
888 	}
889 
890 	/* Clear any error bits before libata starts issuing commands */
891 	clear_serror();
892 	ap->private_data = hsdevp;
893 	dev_dbg(ap->dev, "%s: done\n", __func__);
894 	return 0;
895 
896 CLEANUP_ALLOC:
897 	kfree(hsdevp);
898 CLEANUP:
899 	dev_dbg(ap->dev, "%s: fail. ap->id = %d\n", __func__, ap->print_id);
900 	return err;
901 }
902 
903 static void sata_dwc_port_stop(struct ata_port *ap)
904 {
905 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
906 
907 	dev_dbg(ap->dev, "%s: ap->id = %d\n", __func__, ap->print_id);
908 
909 	dmaengine_terminate_all(hsdevp->chan);
910 	dma_release_channel(hsdevp->chan);
911 
912 	kfree(hsdevp);
913 	ap->private_data = NULL;
914 }
915 
916 /*
917  * Function : sata_dwc_exec_command_by_tag
918  * arguments : ata_port *ap, ata_taskfile *tf, u8 tag, u32 cmd_issued
919  * Return value : None
920  * This function keeps track of individual command tag ids and calls
921  * ata_exec_command in libata
922  */
923 static void sata_dwc_exec_command_by_tag(struct ata_port *ap,
924 					 struct ata_taskfile *tf,
925 					 u8 tag, u32 cmd_issued)
926 {
927 	unsigned long flags;
928 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
929 
930 	dev_dbg(ap->dev, "%s cmd(0x%02x): %s tag=%d\n", __func__, tf->command,
931 		ata_get_cmd_descript(tf->command), tag);
932 
933 	spin_lock_irqsave(&ap->host->lock, flags);
934 	hsdevp->cmd_issued[tag] = cmd_issued;
935 	spin_unlock_irqrestore(&ap->host->lock, flags);
936 	/*
937 	 * Clear SError before executing a new command.
938 	 * sata_dwc_scr_write and read can not be used here. Clearing the PM
939 	 * managed SError register for the disk needs to be done before the
940 	 * task file is loaded.
941 	 */
942 	clear_serror();
943 	ata_sff_exec_command(ap, tf);
944 }
945 
946 static void sata_dwc_bmdma_setup_by_tag(struct ata_queued_cmd *qc, u8 tag)
947 {
948 	sata_dwc_exec_command_by_tag(qc->ap, &qc->tf, tag,
949 				     SATA_DWC_CMD_ISSUED_PEND);
950 }
951 
952 static void sata_dwc_bmdma_setup(struct ata_queued_cmd *qc)
953 {
954 	u8 tag = qc->tag;
955 
956 	if (ata_is_ncq(qc->tf.protocol)) {
957 		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
958 			__func__, qc->ap->link.sactive, tag);
959 	} else {
960 		tag = 0;
961 	}
962 	sata_dwc_bmdma_setup_by_tag(qc, tag);
963 }
964 
965 static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag)
966 {
967 	int start_dma;
968 	u32 reg;
969 	struct sata_dwc_device *hsdev = HSDEV_FROM_QC(qc);
970 	struct ata_port *ap = qc->ap;
971 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
972 	struct dma_async_tx_descriptor *desc = hsdevp->desc[tag];
973 	int dir = qc->dma_dir;
974 
975 	if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_NOT) {
976 		start_dma = 1;
977 		if (dir == DMA_TO_DEVICE)
978 			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_TX;
979 		else
980 			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_RX;
981 	} else {
982 		dev_err(ap->dev,
983 			"%s: Command not pending cmd_issued=%d (tag=%d) DMA NOT started\n",
984 			__func__, hsdevp->cmd_issued[tag], tag);
985 		start_dma = 0;
986 	}
987 
988 	dev_dbg(ap->dev,
989 		"%s qc=%p tag: %x cmd: 0x%02x dma_dir: %s start_dma? %x\n",
990 		__func__, qc, tag, qc->tf.command,
991 		get_dma_dir_descript(qc->dma_dir), start_dma);
992 	sata_dwc_tf_dump(ap, &qc->tf);
993 
994 	if (start_dma) {
995 		reg = core_scr_read(SCR_ERROR);
996 		if (reg & SATA_DWC_SERROR_ERR_BITS) {
997 			dev_err(ap->dev, "%s: ****** SError=0x%08x ******\n",
998 				__func__, reg);
999 		}
1000 
1001 		if (dir == DMA_TO_DEVICE)
1002 			out_le32(&hsdev->sata_dwc_regs->dmacr,
1003 				SATA_DWC_DMACR_TXCHEN);
1004 		else
1005 			out_le32(&hsdev->sata_dwc_regs->dmacr,
1006 				SATA_DWC_DMACR_RXCHEN);
1007 
1008 		/* Enable AHB DMA transfer on the specified channel */
1009 		dmaengine_submit(desc);
1010 		dma_async_issue_pending(hsdevp->chan);
1011 	}
1012 }
1013 
1014 static void sata_dwc_bmdma_start(struct ata_queued_cmd *qc)
1015 {
1016 	u8 tag = qc->tag;
1017 
1018 	if (ata_is_ncq(qc->tf.protocol)) {
1019 		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
1020 			__func__, qc->ap->link.sactive, tag);
1021 	} else {
1022 		tag = 0;
1023 	}
1024 	dev_dbg(qc->ap->dev, "%s\n", __func__);
1025 	sata_dwc_bmdma_start_by_tag(qc, tag);
1026 }
1027 
1028 /*
1029  * Function : sata_dwc_qc_prep_by_tag
1030  * arguments : ata_queued_cmd *qc, u8 tag
1031  * Return value : None
1032  * qc_prep for a particular queued command based on tag
1033  */
1034 static void sata_dwc_qc_prep_by_tag(struct ata_queued_cmd *qc, u8 tag)
1035 {
1036 	struct dma_async_tx_descriptor *desc;
1037 	struct ata_port *ap = qc->ap;
1038 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1039 
1040 	dev_dbg(ap->dev, "%s: port=%d dma dir=%s n_elem=%d\n",
1041 		__func__, ap->port_no, get_dma_dir_descript(qc->dma_dir),
1042 		 qc->n_elem);
1043 
1044 	desc = dma_dwc_xfer_setup(qc);
1045 	if (!desc) {
1046 		dev_err(ap->dev, "%s: dma_dwc_xfer_setup returns NULL\n",
1047 			__func__);
1048 		return;
1049 	}
1050 	hsdevp->desc[tag] = desc;
1051 }
1052 
1053 static unsigned int sata_dwc_qc_issue(struct ata_queued_cmd *qc)
1054 {
1055 	u32 sactive;
1056 	u8 tag = qc->tag;
1057 	struct ata_port *ap = qc->ap;
1058 
1059 #ifdef DEBUG_NCQ
1060 	if (qc->tag > 0 || ap->link.sactive > 1)
1061 		dev_info(ap->dev,
1062 			 "%s ap id=%d cmd(0x%02x)=%s qc tag=%d prot=%s ap active_tag=0x%08x ap sactive=0x%08x\n",
1063 			 __func__, ap->print_id, qc->tf.command,
1064 			 ata_get_cmd_descript(qc->tf.command),
1065 			 qc->tag, get_prot_descript(qc->tf.protocol),
1066 			 ap->link.active_tag, ap->link.sactive);
1067 #endif
1068 
1069 	if (!ata_is_ncq(qc->tf.protocol))
1070 		tag = 0;
1071 	sata_dwc_qc_prep_by_tag(qc, tag);
1072 
1073 	if (ata_is_ncq(qc->tf.protocol)) {
1074 		sactive = core_scr_read(SCR_ACTIVE);
1075 		sactive |= (0x00000001 << tag);
1076 		core_scr_write(SCR_ACTIVE, sactive);
1077 
1078 		dev_dbg(qc->ap->dev,
1079 			"%s: tag=%d ap->link.sactive = 0x%08x sactive=0x%08x\n",
1080 			__func__, tag, qc->ap->link.sactive, sactive);
1081 
1082 		ap->ops->sff_tf_load(ap, &qc->tf);
1083 		sata_dwc_exec_command_by_tag(ap, &qc->tf, qc->tag,
1084 					     SATA_DWC_CMD_ISSUED_PEND);
1085 	} else {
1086 		ata_sff_qc_issue(qc);
1087 	}
1088 	return 0;
1089 }
1090 
1091 /*
1092  * Function : sata_dwc_qc_prep
1093  * arguments : ata_queued_cmd *qc
1094  * Return value : None
1095  * qc_prep for a particular queued command
1096  */
1097 
1098 static void sata_dwc_qc_prep(struct ata_queued_cmd *qc)
1099 {
1100 	if ((qc->dma_dir == DMA_NONE) || (qc->tf.protocol == ATA_PROT_PIO))
1101 		return;
1102 
1103 #ifdef DEBUG_NCQ
1104 	if (qc->tag > 0)
1105 		dev_info(qc->ap->dev, "%s: qc->tag=%d ap->active_tag=0x%08x\n",
1106 			 __func__, qc->tag, qc->ap->link.active_tag);
1107 
1108 	return ;
1109 #endif
1110 }
1111 
1112 static void sata_dwc_error_handler(struct ata_port *ap)
1113 {
1114 	ata_sff_error_handler(ap);
1115 }
1116 
1117 static int sata_dwc_hardreset(struct ata_link *link, unsigned int *class,
1118 			      unsigned long deadline)
1119 {
1120 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(link->ap);
1121 	int ret;
1122 
1123 	ret = sata_sff_hardreset(link, class, deadline);
1124 
1125 	sata_dwc_enable_interrupts(hsdev);
1126 
1127 	/* Reconfigure the DMA control register */
1128 	out_le32(&hsdev->sata_dwc_regs->dmacr,
1129 		 SATA_DWC_DMACR_TXRXCH_CLEAR);
1130 
1131 	/* Reconfigure the DMA Burst Transaction Size register */
1132 	out_le32(&hsdev->sata_dwc_regs->dbtsr,
1133 		 SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
1134 		 SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT));
1135 
1136 	return ret;
1137 }
1138 
1139 /*
1140  * scsi mid-layer and libata interface structures
1141  */
1142 static struct scsi_host_template sata_dwc_sht = {
1143 	ATA_NCQ_SHT(DRV_NAME),
1144 	/*
1145 	 * test-only: Currently this driver doesn't handle NCQ
1146 	 * correctly. We enable NCQ but set the queue depth to a
1147 	 * max of 1. This will get fixed in in a future release.
1148 	 */
1149 	.sg_tablesize		= LIBATA_MAX_PRD,
1150 	/* .can_queue		= ATA_MAX_QUEUE, */
1151 	.dma_boundary		= ATA_DMA_BOUNDARY,
1152 };
1153 
1154 static struct ata_port_operations sata_dwc_ops = {
1155 	.inherits		= &ata_sff_port_ops,
1156 
1157 	.error_handler		= sata_dwc_error_handler,
1158 	.hardreset		= sata_dwc_hardreset,
1159 
1160 	.qc_prep		= sata_dwc_qc_prep,
1161 	.qc_issue		= sata_dwc_qc_issue,
1162 
1163 	.scr_read		= sata_dwc_scr_read,
1164 	.scr_write		= sata_dwc_scr_write,
1165 
1166 	.port_start		= sata_dwc_port_start,
1167 	.port_stop		= sata_dwc_port_stop,
1168 
1169 	.bmdma_setup		= sata_dwc_bmdma_setup,
1170 	.bmdma_start		= sata_dwc_bmdma_start,
1171 };
1172 
1173 static const struct ata_port_info sata_dwc_port_info[] = {
1174 	{
1175 		.flags		= ATA_FLAG_SATA | ATA_FLAG_NCQ,
1176 		.pio_mask	= ATA_PIO4,
1177 		.udma_mask	= ATA_UDMA6,
1178 		.port_ops	= &sata_dwc_ops,
1179 	},
1180 };
1181 
1182 static int sata_dwc_probe(struct platform_device *ofdev)
1183 {
1184 	struct sata_dwc_device *hsdev;
1185 	u32 idr, versionr;
1186 	char *ver = (char *)&versionr;
1187 	u8 __iomem *base;
1188 	int err = 0;
1189 	int irq;
1190 	struct ata_host *host;
1191 	struct ata_port_info pi = sata_dwc_port_info[0];
1192 	const struct ata_port_info *ppi[] = { &pi, NULL };
1193 	struct device_node *np = ofdev->dev.of_node;
1194 
1195 	/* Allocate DWC SATA device */
1196 	host = ata_host_alloc_pinfo(&ofdev->dev, ppi, SATA_DWC_MAX_PORTS);
1197 	hsdev = devm_kzalloc(&ofdev->dev, sizeof(*hsdev), GFP_KERNEL);
1198 	if (!host || !hsdev)
1199 		return -ENOMEM;
1200 
1201 	host->private_data = hsdev;
1202 
1203 	/* Ioremap SATA registers */
1204 	base = of_iomap(np, 0);
1205 	if (!base) {
1206 		dev_err(&ofdev->dev,
1207 			"ioremap failed for SATA register address\n");
1208 		return -ENODEV;
1209 	}
1210 	hsdev->reg_base = base;
1211 	dev_dbg(&ofdev->dev, "ioremap done for SATA register address\n");
1212 
1213 	/* Synopsys DWC SATA specific Registers */
1214 	hsdev->sata_dwc_regs = (void *__iomem)(base + SATA_DWC_REG_OFFSET);
1215 
1216 	/* Setup port */
1217 	host->ports[0]->ioaddr.cmd_addr = base;
1218 	host->ports[0]->ioaddr.scr_addr = base + SATA_DWC_SCR_OFFSET;
1219 	host_pvt.scr_addr_sstatus = base + SATA_DWC_SCR_OFFSET;
1220 	sata_dwc_setup_port(&host->ports[0]->ioaddr, (unsigned long)base);
1221 
1222 	/* Read the ID and Version Registers */
1223 	idr = in_le32(&hsdev->sata_dwc_regs->idr);
1224 	versionr = in_le32(&hsdev->sata_dwc_regs->versionr);
1225 	dev_notice(&ofdev->dev, "id %d, controller version %c.%c%c\n",
1226 		   idr, ver[0], ver[1], ver[2]);
1227 
1228 	/* Get SATA DMA interrupt number */
1229 	hsdev->dma->irq = irq_of_parse_and_map(np, 1);
1230 	if (hsdev->dma->irq == NO_IRQ) {
1231 		dev_err(&ofdev->dev, "no SATA DMA irq\n");
1232 		err = -ENODEV;
1233 		goto error_iomap;
1234 	}
1235 
1236 	/* Get physical SATA DMA register base address */
1237 	hsdev->dma->regs = of_iomap(np, 1);
1238 	if (!hsdev->dma->regs) {
1239 		dev_err(&ofdev->dev,
1240 			"ioremap failed for AHBDMA register address\n");
1241 		err = -ENODEV;
1242 		goto error_iomap;
1243 	}
1244 
1245 	/* Save dev for later use in dev_xxx() routines */
1246 	hsdev->dev = &ofdev->dev;
1247 
1248 	hsdev->dma->dev = &ofdev->dev;
1249 
1250 	/* Initialize AHB DMAC */
1251 	err = dw_dma_probe(hsdev->dma, NULL);
1252 	if (err)
1253 		goto error_dma_iomap;
1254 
1255 	/* Enable SATA Interrupts */
1256 	sata_dwc_enable_interrupts(hsdev);
1257 
1258 	/* Get SATA interrupt number */
1259 	irq = irq_of_parse_and_map(np, 0);
1260 	if (irq == NO_IRQ) {
1261 		dev_err(&ofdev->dev, "no SATA DMA irq\n");
1262 		err = -ENODEV;
1263 		goto error_out;
1264 	}
1265 
1266 	/*
1267 	 * Now, register with libATA core, this will also initiate the
1268 	 * device discovery process, invoking our port_start() handler &
1269 	 * error_handler() to execute a dummy Softreset EH session
1270 	 */
1271 	err = ata_host_activate(host, irq, sata_dwc_isr, 0, &sata_dwc_sht);
1272 	if (err)
1273 		dev_err(&ofdev->dev, "failed to activate host");
1274 
1275 	dev_set_drvdata(&ofdev->dev, host);
1276 	return 0;
1277 
1278 error_out:
1279 	/* Free SATA DMA resources */
1280 	dw_dma_remove(hsdev->dma);
1281 error_dma_iomap:
1282 	iounmap(hsdev->dma->regs);
1283 error_iomap:
1284 	iounmap(base);
1285 	return err;
1286 }
1287 
1288 static int sata_dwc_remove(struct platform_device *ofdev)
1289 {
1290 	struct device *dev = &ofdev->dev;
1291 	struct ata_host *host = dev_get_drvdata(dev);
1292 	struct sata_dwc_device *hsdev = host->private_data;
1293 
1294 	ata_host_detach(host);
1295 
1296 	/* Free SATA DMA resources */
1297 	dw_dma_remove(hsdev->dma);
1298 
1299 	iounmap(hsdev->dma->regs);
1300 	iounmap(hsdev->reg_base);
1301 	dev_dbg(&ofdev->dev, "done\n");
1302 	return 0;
1303 }
1304 
1305 static const struct of_device_id sata_dwc_match[] = {
1306 	{ .compatible = "amcc,sata-460ex", },
1307 	{}
1308 };
1309 MODULE_DEVICE_TABLE(of, sata_dwc_match);
1310 
1311 static struct platform_driver sata_dwc_driver = {
1312 	.driver = {
1313 		.name = DRV_NAME,
1314 		.of_match_table = sata_dwc_match,
1315 	},
1316 	.probe = sata_dwc_probe,
1317 	.remove = sata_dwc_remove,
1318 };
1319 
1320 module_platform_driver(sata_dwc_driver);
1321 
1322 MODULE_LICENSE("GPL");
1323 MODULE_AUTHOR("Mark Miesfeld <mmiesfeld@amcc.com>");
1324 MODULE_DESCRIPTION("DesignWare Cores SATA controller low level driver");
1325 MODULE_VERSION(DRV_VERSION);
1326