xref: /openbmc/linux/drivers/ata/sata_dwc_460ex.c (revision bc000245)
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/init.h>
33 #include <linux/device.h>
34 #include <linux/of_address.h>
35 #include <linux/of_irq.h>
36 #include <linux/of_platform.h>
37 #include <linux/platform_device.h>
38 #include <linux/libata.h>
39 #include <linux/slab.h>
40 #include "libata.h"
41 
42 #include <scsi/scsi_host.h>
43 #include <scsi/scsi_cmnd.h>
44 
45 /* These two are defined in "libata.h" */
46 #undef	DRV_NAME
47 #undef	DRV_VERSION
48 
49 #define DRV_NAME        "sata-dwc"
50 #define DRV_VERSION     "1.3"
51 
52 /* SATA DMA driver Globals */
53 #define DMA_NUM_CHANS		1
54 #define DMA_NUM_CHAN_REGS	8
55 
56 /* SATA DMA Register definitions */
57 #define AHB_DMA_BRST_DFLT	64	/* 16 data items burst length*/
58 
59 struct dmareg {
60 	u32 low;		/* Low bits 0-31 */
61 	u32 high;		/* High bits 32-63 */
62 };
63 
64 /* DMA Per Channel registers */
65 struct dma_chan_regs {
66 	struct dmareg sar;	/* Source Address */
67 	struct dmareg dar;	/* Destination address */
68 	struct dmareg llp;	/* Linked List Pointer */
69 	struct dmareg ctl;	/* Control */
70 	struct dmareg sstat;	/* Source Status not implemented in core */
71 	struct dmareg dstat;	/* Destination Status not implemented in core*/
72 	struct dmareg sstatar;	/* Source Status Address not impl in core */
73 	struct dmareg dstatar;	/* Destination Status Address not implemente */
74 	struct dmareg cfg;	/* Config */
75 	struct dmareg sgr;	/* Source Gather */
76 	struct dmareg dsr;	/* Destination Scatter */
77 };
78 
79 /* Generic Interrupt Registers */
80 struct dma_interrupt_regs {
81 	struct dmareg tfr;	/* Transfer Interrupt */
82 	struct dmareg block;	/* Block Interrupt */
83 	struct dmareg srctran;	/* Source Transfer Interrupt */
84 	struct dmareg dsttran;	/* Dest Transfer Interrupt */
85 	struct dmareg error;	/* Error */
86 };
87 
88 struct ahb_dma_regs {
89 	struct dma_chan_regs	chan_regs[DMA_NUM_CHAN_REGS];
90 	struct dma_interrupt_regs interrupt_raw;	/* Raw Interrupt */
91 	struct dma_interrupt_regs interrupt_status;	/* Interrupt Status */
92 	struct dma_interrupt_regs interrupt_mask;	/* Interrupt Mask */
93 	struct dma_interrupt_regs interrupt_clear;	/* Interrupt Clear */
94 	struct dmareg		statusInt;	/* Interrupt combined*/
95 	struct dmareg		rq_srcreg;	/* Src Trans Req */
96 	struct dmareg		rq_dstreg;	/* Dst Trans Req */
97 	struct dmareg		rq_sgl_srcreg;	/* Sngl Src Trans Req*/
98 	struct dmareg		rq_sgl_dstreg;	/* Sngl Dst Trans Req*/
99 	struct dmareg		rq_lst_srcreg;	/* Last Src Trans Req*/
100 	struct dmareg		rq_lst_dstreg;	/* Last Dst Trans Req*/
101 	struct dmareg		dma_cfg;		/* DMA Config */
102 	struct dmareg		dma_chan_en;		/* DMA Channel Enable*/
103 	struct dmareg		dma_id;			/* DMA ID */
104 	struct dmareg		dma_test;		/* DMA Test */
105 	struct dmareg		res1;			/* reserved */
106 	struct dmareg		res2;			/* reserved */
107 	/*
108 	 * DMA Comp Params
109 	 * Param 6 = dma_param[0], Param 5 = dma_param[1],
110 	 * Param 4 = dma_param[2] ...
111 	 */
112 	struct dmareg		dma_params[6];
113 };
114 
115 /* Data structure for linked list item */
116 struct lli {
117 	u32		sar;		/* Source Address */
118 	u32		dar;		/* Destination address */
119 	u32		llp;		/* Linked List Pointer */
120 	struct dmareg	ctl;		/* Control */
121 	struct dmareg	dstat;		/* Destination Status */
122 };
123 
124 enum {
125 	SATA_DWC_DMAC_LLI_SZ =	(sizeof(struct lli)),
126 	SATA_DWC_DMAC_LLI_NUM =	256,
127 	SATA_DWC_DMAC_LLI_TBL_SZ = (SATA_DWC_DMAC_LLI_SZ * \
128 					SATA_DWC_DMAC_LLI_NUM),
129 	SATA_DWC_DMAC_TWIDTH_BYTES = 4,
130 	SATA_DWC_DMAC_CTRL_TSIZE_MAX = (0x00000800 * \
131 						SATA_DWC_DMAC_TWIDTH_BYTES),
132 };
133 
134 /* DMA Register Operation Bits */
135 enum {
136 	DMA_EN	=		0x00000001, /* Enable AHB DMA */
137 	DMA_CTL_LLP_SRCEN =	0x10000000, /* Blk chain enable Src */
138 	DMA_CTL_LLP_DSTEN =	0x08000000, /* Blk chain enable Dst */
139 };
140 
141 #define	DMA_CTL_BLK_TS(size)	((size) & 0x000000FFF)	/* Blk Transfer size */
142 #define DMA_CHANNEL(ch)		(0x00000001 << (ch))	/* Select channel */
143 	/* Enable channel */
144 #define	DMA_ENABLE_CHAN(ch)	((0x00000001 << (ch)) |			\
145 				 ((0x000000001 << (ch)) << 8))
146 	/* Disable channel */
147 #define	DMA_DISABLE_CHAN(ch)	(0x00000000 | ((0x000000001 << (ch)) << 8))
148 	/* Transfer Type & Flow Controller */
149 #define	DMA_CTL_TTFC(type)	(((type) & 0x7) << 20)
150 #define	DMA_CTL_SMS(num)	(((num) & 0x3) << 25) /* Src Master Select */
151 #define	DMA_CTL_DMS(num)	(((num) & 0x3) << 23)/* Dst Master Select */
152 	/* Src Burst Transaction Length */
153 #define DMA_CTL_SRC_MSIZE(size) (((size) & 0x7) << 14)
154 	/* Dst Burst Transaction Length */
155 #define	DMA_CTL_DST_MSIZE(size) (((size) & 0x7) << 11)
156 	/* Source Transfer Width */
157 #define	DMA_CTL_SRC_TRWID(size) (((size) & 0x7) << 4)
158 	/* Destination Transfer Width */
159 #define	DMA_CTL_DST_TRWID(size) (((size) & 0x7) << 1)
160 
161 /* Assign HW handshaking interface (x) to destination / source peripheral */
162 #define	DMA_CFG_HW_HS_DEST(int_num) (((int_num) & 0xF) << 11)
163 #define	DMA_CFG_HW_HS_SRC(int_num) (((int_num) & 0xF) << 7)
164 #define	DMA_CFG_HW_CH_PRIOR(int_num) (((int_num) & 0xF) << 5)
165 #define	DMA_LLP_LMS(addr, master) (((addr) & 0xfffffffc) | (master))
166 
167 /*
168  * This define is used to set block chaining disabled in the control low
169  * register.  It is already in little endian format so it can be &'d dirctly.
170  * It is essentially: cpu_to_le32(~(DMA_CTL_LLP_SRCEN | DMA_CTL_LLP_DSTEN))
171  */
172 enum {
173 	DMA_CTL_LLP_DISABLE_LE32 = 0xffffffe7,
174 	DMA_CTL_TTFC_P2M_DMAC =	0x00000002, /* Per to mem, DMAC cntr */
175 	DMA_CTL_TTFC_M2P_PER =	0x00000003, /* Mem to per, peripheral cntr */
176 	DMA_CTL_SINC_INC =	0x00000000, /* Source Address Increment */
177 	DMA_CTL_SINC_DEC =	0x00000200,
178 	DMA_CTL_SINC_NOCHANGE =	0x00000400,
179 	DMA_CTL_DINC_INC =	0x00000000, /* Destination Address Increment */
180 	DMA_CTL_DINC_DEC =	0x00000080,
181 	DMA_CTL_DINC_NOCHANGE =	0x00000100,
182 	DMA_CTL_INT_EN =	0x00000001, /* Interrupt Enable */
183 
184 /* Channel Configuration Register high bits */
185 	DMA_CFG_FCMOD_REQ =	0x00000001, /* Flow Control - request based */
186 	DMA_CFG_PROTCTL	=	(0x00000003 << 2),/* Protection Control */
187 
188 /* Channel Configuration Register low bits */
189 	DMA_CFG_RELD_DST =	0x80000000, /* Reload Dest / Src Addr */
190 	DMA_CFG_RELD_SRC =	0x40000000,
191 	DMA_CFG_HS_SELSRC =	0x00000800, /* Software handshake Src/ Dest */
192 	DMA_CFG_HS_SELDST =	0x00000400,
193 	DMA_CFG_FIFOEMPTY =     (0x00000001 << 9), /* FIFO Empty bit */
194 
195 /* Channel Linked List Pointer Register */
196 	DMA_LLP_AHBMASTER1 =	0,	/* List Master Select */
197 	DMA_LLP_AHBMASTER2 =	1,
198 
199 	SATA_DWC_MAX_PORTS = 1,
200 
201 	SATA_DWC_SCR_OFFSET = 0x24,
202 	SATA_DWC_REG_OFFSET = 0x64,
203 };
204 
205 /* DWC SATA Registers */
206 struct sata_dwc_regs {
207 	u32 fptagr;		/* 1st party DMA tag */
208 	u32 fpbor;		/* 1st party DMA buffer offset */
209 	u32 fptcr;		/* 1st party DMA Xfr count */
210 	u32 dmacr;		/* DMA Control */
211 	u32 dbtsr;		/* DMA Burst Transac size */
212 	u32 intpr;		/* Interrupt Pending */
213 	u32 intmr;		/* Interrupt Mask */
214 	u32 errmr;		/* Error Mask */
215 	u32 llcr;		/* Link Layer Control */
216 	u32 phycr;		/* PHY Control */
217 	u32 physr;		/* PHY Status */
218 	u32 rxbistpd;		/* Recvd BIST pattern def register */
219 	u32 rxbistpd1;		/* Recvd BIST data dword1 */
220 	u32 rxbistpd2;		/* Recvd BIST pattern data dword2 */
221 	u32 txbistpd;		/* Trans BIST pattern def register */
222 	u32 txbistpd1;		/* Trans BIST data dword1 */
223 	u32 txbistpd2;		/* Trans BIST data dword2 */
224 	u32 bistcr;		/* BIST Control Register */
225 	u32 bistfctr;		/* BIST FIS Count Register */
226 	u32 bistsr;		/* BIST Status Register */
227 	u32 bistdecr;		/* BIST Dword Error count register */
228 	u32 res[15];		/* Reserved locations */
229 	u32 testr;		/* Test Register */
230 	u32 versionr;		/* Version Register */
231 	u32 idr;		/* ID Register */
232 	u32 unimpl[192];	/* Unimplemented */
233 	u32 dmadr[256];	/* FIFO Locations in DMA Mode */
234 };
235 
236 enum {
237 	SCR_SCONTROL_DET_ENABLE	=	0x00000001,
238 	SCR_SSTATUS_DET_PRESENT	=	0x00000001,
239 	SCR_SERROR_DIAG_X	=	0x04000000,
240 /* DWC SATA Register Operations */
241 	SATA_DWC_TXFIFO_DEPTH	=	0x01FF,
242 	SATA_DWC_RXFIFO_DEPTH	=	0x01FF,
243 	SATA_DWC_DMACR_TMOD_TXCHEN =	0x00000004,
244 	SATA_DWC_DMACR_TXCHEN	= (0x00000001 | SATA_DWC_DMACR_TMOD_TXCHEN),
245 	SATA_DWC_DMACR_RXCHEN	= (0x00000002 | SATA_DWC_DMACR_TMOD_TXCHEN),
246 	SATA_DWC_DMACR_TXRXCH_CLEAR =	SATA_DWC_DMACR_TMOD_TXCHEN,
247 	SATA_DWC_INTPR_DMAT	=	0x00000001,
248 	SATA_DWC_INTPR_NEWFP	=	0x00000002,
249 	SATA_DWC_INTPR_PMABRT	=	0x00000004,
250 	SATA_DWC_INTPR_ERR	=	0x00000008,
251 	SATA_DWC_INTPR_NEWBIST	=	0x00000010,
252 	SATA_DWC_INTPR_IPF	=	0x10000000,
253 	SATA_DWC_INTMR_DMATM	=	0x00000001,
254 	SATA_DWC_INTMR_NEWFPM	=	0x00000002,
255 	SATA_DWC_INTMR_PMABRTM	=	0x00000004,
256 	SATA_DWC_INTMR_ERRM	=	0x00000008,
257 	SATA_DWC_INTMR_NEWBISTM	=	0x00000010,
258 	SATA_DWC_LLCR_SCRAMEN	=	0x00000001,
259 	SATA_DWC_LLCR_DESCRAMEN	=	0x00000002,
260 	SATA_DWC_LLCR_RPDEN	=	0x00000004,
261 /* This is all error bits, zero's are reserved fields. */
262 	SATA_DWC_SERROR_ERR_BITS =	0x0FFF0F03
263 };
264 
265 #define SATA_DWC_SCR0_SPD_GET(v)	(((v) >> 4) & 0x0000000F)
266 #define SATA_DWC_DMACR_TX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_TXCHEN) |\
267 						 SATA_DWC_DMACR_TMOD_TXCHEN)
268 #define SATA_DWC_DMACR_RX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_RXCHEN) |\
269 						 SATA_DWC_DMACR_TMOD_TXCHEN)
270 #define SATA_DWC_DBTSR_MWR(size)	(((size)/4) & SATA_DWC_TXFIFO_DEPTH)
271 #define SATA_DWC_DBTSR_MRD(size)	((((size)/4) & SATA_DWC_RXFIFO_DEPTH)\
272 						 << 16)
273 struct sata_dwc_device {
274 	struct device		*dev;		/* generic device struct */
275 	struct ata_probe_ent	*pe;		/* ptr to probe-ent */
276 	struct ata_host		*host;
277 	u8			*reg_base;
278 	struct sata_dwc_regs	*sata_dwc_regs;	/* DW Synopsys SATA specific */
279 	int			irq_dma;
280 };
281 
282 #define SATA_DWC_QCMD_MAX	32
283 
284 struct sata_dwc_device_port {
285 	struct sata_dwc_device	*hsdev;
286 	int			cmd_issued[SATA_DWC_QCMD_MAX];
287 	struct lli		*llit[SATA_DWC_QCMD_MAX];  /* DMA LLI table */
288 	dma_addr_t		llit_dma[SATA_DWC_QCMD_MAX];
289 	u32			dma_chan[SATA_DWC_QCMD_MAX];
290 	int			dma_pending[SATA_DWC_QCMD_MAX];
291 };
292 
293 /*
294  * Commonly used DWC SATA driver Macros
295  */
296 #define HSDEV_FROM_HOST(host)  ((struct sata_dwc_device *)\
297 					(host)->private_data)
298 #define HSDEV_FROM_AP(ap)  ((struct sata_dwc_device *)\
299 					(ap)->host->private_data)
300 #define HSDEVP_FROM_AP(ap)   ((struct sata_dwc_device_port *)\
301 					(ap)->private_data)
302 #define HSDEV_FROM_QC(qc)	((struct sata_dwc_device *)\
303 					(qc)->ap->host->private_data)
304 #define HSDEV_FROM_HSDEVP(p)	((struct sata_dwc_device *)\
305 						(hsdevp)->hsdev)
306 
307 enum {
308 	SATA_DWC_CMD_ISSUED_NOT		= 0,
309 	SATA_DWC_CMD_ISSUED_PEND	= 1,
310 	SATA_DWC_CMD_ISSUED_EXEC	= 2,
311 	SATA_DWC_CMD_ISSUED_NODATA	= 3,
312 
313 	SATA_DWC_DMA_PENDING_NONE	= 0,
314 	SATA_DWC_DMA_PENDING_TX		= 1,
315 	SATA_DWC_DMA_PENDING_RX		= 2,
316 };
317 
318 struct sata_dwc_host_priv {
319 	void	__iomem	 *scr_addr_sstatus;
320 	u32	sata_dwc_sactive_issued ;
321 	u32	sata_dwc_sactive_queued ;
322 	u32	dma_interrupt_count;
323 	struct	ahb_dma_regs	*sata_dma_regs;
324 	struct	device	*dwc_dev;
325 	int	dma_channel;
326 };
327 struct sata_dwc_host_priv host_pvt;
328 /*
329  * Prototypes
330  */
331 static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag);
332 static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
333 				u32 check_status);
334 static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status);
335 static void sata_dwc_port_stop(struct ata_port *ap);
336 static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag);
337 static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq);
338 static void dma_dwc_exit(struct sata_dwc_device *hsdev);
339 static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
340 			      struct lli *lli, dma_addr_t dma_lli,
341 			      void __iomem *addr, int dir);
342 static void dma_dwc_xfer_start(int dma_ch);
343 
344 static const char *get_prot_descript(u8 protocol)
345 {
346 	switch ((enum ata_tf_protocols)protocol) {
347 	case ATA_PROT_NODATA:
348 		return "ATA no data";
349 	case ATA_PROT_PIO:
350 		return "ATA PIO";
351 	case ATA_PROT_DMA:
352 		return "ATA DMA";
353 	case ATA_PROT_NCQ:
354 		return "ATA NCQ";
355 	case ATAPI_PROT_NODATA:
356 		return "ATAPI no data";
357 	case ATAPI_PROT_PIO:
358 		return "ATAPI PIO";
359 	case ATAPI_PROT_DMA:
360 		return "ATAPI DMA";
361 	default:
362 		return "unknown";
363 	}
364 }
365 
366 static const char *get_dma_dir_descript(int dma_dir)
367 {
368 	switch ((enum dma_data_direction)dma_dir) {
369 	case DMA_BIDIRECTIONAL:
370 		return "bidirectional";
371 	case DMA_TO_DEVICE:
372 		return "to device";
373 	case DMA_FROM_DEVICE:
374 		return "from device";
375 	default:
376 		return "none";
377 	}
378 }
379 
380 static void sata_dwc_tf_dump(struct ata_taskfile *tf)
381 {
382 	dev_vdbg(host_pvt.dwc_dev, "taskfile cmd: 0x%02x protocol: %s flags:"
383 		"0x%lx device: %x\n", tf->command,
384 		get_prot_descript(tf->protocol), tf->flags, tf->device);
385 	dev_vdbg(host_pvt.dwc_dev, "feature: 0x%02x nsect: 0x%x lbal: 0x%x "
386 		"lbam: 0x%x lbah: 0x%x\n", tf->feature, tf->nsect, tf->lbal,
387 		 tf->lbam, tf->lbah);
388 	dev_vdbg(host_pvt.dwc_dev, "hob_feature: 0x%02x hob_nsect: 0x%x "
389 		"hob_lbal: 0x%x hob_lbam: 0x%x hob_lbah: 0x%x\n",
390 		tf->hob_feature, tf->hob_nsect, tf->hob_lbal, tf->hob_lbam,
391 		tf->hob_lbah);
392 }
393 
394 /*
395  * Function: get_burst_length_encode
396  * arguments: datalength: length in bytes of data
397  * returns value to be programmed in register corresponding to data length
398  * This value is effectively the log(base 2) of the length
399  */
400 static  int get_burst_length_encode(int datalength)
401 {
402 	int items = datalength >> 2;	/* div by 4 to get lword count */
403 
404 	if (items >= 64)
405 		return 5;
406 
407 	if (items >= 32)
408 		return 4;
409 
410 	if (items >= 16)
411 		return 3;
412 
413 	if (items >= 8)
414 		return 2;
415 
416 	if (items >= 4)
417 		return 1;
418 
419 	return 0;
420 }
421 
422 static  void clear_chan_interrupts(int c)
423 {
424 	out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.tfr.low),
425 		 DMA_CHANNEL(c));
426 	out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.block.low),
427 		 DMA_CHANNEL(c));
428 	out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.srctran.low),
429 		 DMA_CHANNEL(c));
430 	out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.dsttran.low),
431 		 DMA_CHANNEL(c));
432 	out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.error.low),
433 		 DMA_CHANNEL(c));
434 }
435 
436 /*
437  * Function: dma_request_channel
438  * arguments: None
439  * returns channel number if available else -1
440  * This function assigns the next available DMA channel from the list to the
441  * requester
442  */
443 static int dma_request_channel(void)
444 {
445 	/* Check if the channel is not currently in use */
446 	if (!(in_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low)) &
447 		DMA_CHANNEL(host_pvt.dma_channel)))
448 		return host_pvt.dma_channel;
449 	dev_err(host_pvt.dwc_dev, "%s Channel %d is currently in use\n",
450 		__func__, host_pvt.dma_channel);
451 	return -1;
452 }
453 
454 /*
455  * Function: dma_dwc_interrupt
456  * arguments: irq, dev_id, pt_regs
457  * returns channel number if available else -1
458  * Interrupt Handler for DW AHB SATA DMA
459  */
460 static irqreturn_t dma_dwc_interrupt(int irq, void *hsdev_instance)
461 {
462 	int chan;
463 	u32 tfr_reg, err_reg;
464 	unsigned long flags;
465 	struct sata_dwc_device *hsdev =
466 		(struct sata_dwc_device *)hsdev_instance;
467 	struct ata_host *host = (struct ata_host *)hsdev->host;
468 	struct ata_port *ap;
469 	struct sata_dwc_device_port *hsdevp;
470 	u8 tag = 0;
471 	unsigned int port = 0;
472 
473 	spin_lock_irqsave(&host->lock, flags);
474 	ap = host->ports[port];
475 	hsdevp = HSDEVP_FROM_AP(ap);
476 	tag = ap->link.active_tag;
477 
478 	tfr_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.tfr\
479 			.low));
480 	err_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.error\
481 			.low));
482 
483 	dev_dbg(ap->dev, "eot=0x%08x err=0x%08x pending=%d active port=%d\n",
484 		tfr_reg, err_reg, hsdevp->dma_pending[tag], port);
485 
486 	chan = host_pvt.dma_channel;
487 	if (chan >= 0) {
488 		/* Check for end-of-transfer interrupt. */
489 		if (tfr_reg & DMA_CHANNEL(chan)) {
490 			/*
491 			 * Each DMA command produces 2 interrupts.  Only
492 			 * complete the command after both interrupts have been
493 			 * seen. (See sata_dwc_isr())
494 			 */
495 			host_pvt.dma_interrupt_count++;
496 			sata_dwc_clear_dmacr(hsdevp, tag);
497 
498 			if (hsdevp->dma_pending[tag] ==
499 			    SATA_DWC_DMA_PENDING_NONE) {
500 				dev_err(ap->dev, "DMA not pending eot=0x%08x "
501 					"err=0x%08x tag=0x%02x pending=%d\n",
502 					tfr_reg, err_reg, tag,
503 					hsdevp->dma_pending[tag]);
504 			}
505 
506 			if ((host_pvt.dma_interrupt_count % 2) == 0)
507 				sata_dwc_dma_xfer_complete(ap, 1);
508 
509 			/* Clear the interrupt */
510 			out_le32(&(host_pvt.sata_dma_regs->interrupt_clear\
511 				.tfr.low),
512 				 DMA_CHANNEL(chan));
513 		}
514 
515 		/* Check for error interrupt. */
516 		if (err_reg & DMA_CHANNEL(chan)) {
517 			/* TODO Need error handler ! */
518 			dev_err(ap->dev, "error interrupt err_reg=0x%08x\n",
519 				err_reg);
520 
521 			/* Clear the interrupt. */
522 			out_le32(&(host_pvt.sata_dma_regs->interrupt_clear\
523 				.error.low),
524 				 DMA_CHANNEL(chan));
525 		}
526 	}
527 	spin_unlock_irqrestore(&host->lock, flags);
528 	return IRQ_HANDLED;
529 }
530 
531 /*
532  * Function: dma_request_interrupts
533  * arguments: hsdev
534  * returns status
535  * This function registers ISR for a particular DMA channel interrupt
536  */
537 static int dma_request_interrupts(struct sata_dwc_device *hsdev, int irq)
538 {
539 	int retval = 0;
540 	int chan = host_pvt.dma_channel;
541 
542 	if (chan >= 0) {
543 		/* Unmask error interrupt */
544 		out_le32(&(host_pvt.sata_dma_regs)->interrupt_mask.error.low,
545 			 DMA_ENABLE_CHAN(chan));
546 
547 		/* Unmask end-of-transfer interrupt */
548 		out_le32(&(host_pvt.sata_dma_regs)->interrupt_mask.tfr.low,
549 			 DMA_ENABLE_CHAN(chan));
550 	}
551 
552 	retval = request_irq(irq, dma_dwc_interrupt, 0, "SATA DMA", hsdev);
553 	if (retval) {
554 		dev_err(host_pvt.dwc_dev, "%s: could not get IRQ %d\n",
555 		__func__, irq);
556 		return -ENODEV;
557 	}
558 
559 	/* Mark this interrupt as requested */
560 	hsdev->irq_dma = irq;
561 	return 0;
562 }
563 
564 /*
565  * Function: map_sg_to_lli
566  * The Synopsis driver has a comment proposing that better performance
567  * is possible by only enabling interrupts on the last item in the linked list.
568  * However, it seems that could be a problem if an error happened on one of the
569  * first items.  The transfer would halt, but no error interrupt would occur.
570  * Currently this function sets interrupts enabled for each linked list item:
571  * DMA_CTL_INT_EN.
572  */
573 static int map_sg_to_lli(struct scatterlist *sg, int num_elems,
574 			struct lli *lli, dma_addr_t dma_lli,
575 			void __iomem *dmadr_addr, int dir)
576 {
577 	int i, idx = 0;
578 	int fis_len = 0;
579 	dma_addr_t next_llp;
580 	int bl;
581 	int sms_val, dms_val;
582 
583 	sms_val = 0;
584 	dms_val = 1 + host_pvt.dma_channel;
585 	dev_dbg(host_pvt.dwc_dev, "%s: sg=%p nelem=%d lli=%p dma_lli=0x%08x"
586 		" dmadr=0x%08x\n", __func__, sg, num_elems, lli, (u32)dma_lli,
587 		(u32)dmadr_addr);
588 
589 	bl = get_burst_length_encode(AHB_DMA_BRST_DFLT);
590 
591 	for (i = 0; i < num_elems; i++, sg++) {
592 		u32 addr, offset;
593 		u32 sg_len, len;
594 
595 		addr = (u32) sg_dma_address(sg);
596 		sg_len = sg_dma_len(sg);
597 
598 		dev_dbg(host_pvt.dwc_dev, "%s: elem=%d sg_addr=0x%x sg_len"
599 			"=%d\n", __func__, i, addr, sg_len);
600 
601 		while (sg_len) {
602 			if (idx >= SATA_DWC_DMAC_LLI_NUM) {
603 				/* The LLI table is not large enough. */
604 				dev_err(host_pvt.dwc_dev, "LLI table overrun "
605 				"(idx=%d)\n", idx);
606 				break;
607 			}
608 			len = (sg_len > SATA_DWC_DMAC_CTRL_TSIZE_MAX) ?
609 				SATA_DWC_DMAC_CTRL_TSIZE_MAX : sg_len;
610 
611 			offset = addr & 0xffff;
612 			if ((offset + sg_len) > 0x10000)
613 				len = 0x10000 - offset;
614 
615 			/*
616 			 * Make sure a LLI block is not created that will span
617 			 * 8K max FIS boundary.  If the block spans such a FIS
618 			 * boundary, there is a chance that a DMA burst will
619 			 * cross that boundary -- this results in an error in
620 			 * the host controller.
621 			 */
622 			if (fis_len + len > 8192) {
623 				dev_dbg(host_pvt.dwc_dev, "SPLITTING: fis_len="
624 					"%d(0x%x) len=%d(0x%x)\n", fis_len,
625 					 fis_len, len, len);
626 				len = 8192 - fis_len;
627 				fis_len = 0;
628 			} else {
629 				fis_len += len;
630 			}
631 			if (fis_len == 8192)
632 				fis_len = 0;
633 
634 			/*
635 			 * Set DMA addresses and lower half of control register
636 			 * based on direction.
637 			 */
638 			if (dir == DMA_FROM_DEVICE) {
639 				lli[idx].dar = cpu_to_le32(addr);
640 				lli[idx].sar = cpu_to_le32((u32)dmadr_addr);
641 
642 				lli[idx].ctl.low = cpu_to_le32(
643 					DMA_CTL_TTFC(DMA_CTL_TTFC_P2M_DMAC) |
644 					DMA_CTL_SMS(sms_val) |
645 					DMA_CTL_DMS(dms_val) |
646 					DMA_CTL_SRC_MSIZE(bl) |
647 					DMA_CTL_DST_MSIZE(bl) |
648 					DMA_CTL_SINC_NOCHANGE |
649 					DMA_CTL_SRC_TRWID(2) |
650 					DMA_CTL_DST_TRWID(2) |
651 					DMA_CTL_INT_EN |
652 					DMA_CTL_LLP_SRCEN |
653 					DMA_CTL_LLP_DSTEN);
654 			} else {	/* DMA_TO_DEVICE */
655 				lli[idx].sar = cpu_to_le32(addr);
656 				lli[idx].dar = cpu_to_le32((u32)dmadr_addr);
657 
658 				lli[idx].ctl.low = cpu_to_le32(
659 					DMA_CTL_TTFC(DMA_CTL_TTFC_M2P_PER) |
660 					DMA_CTL_SMS(dms_val) |
661 					DMA_CTL_DMS(sms_val) |
662 					DMA_CTL_SRC_MSIZE(bl) |
663 					DMA_CTL_DST_MSIZE(bl) |
664 					DMA_CTL_DINC_NOCHANGE |
665 					DMA_CTL_SRC_TRWID(2) |
666 					DMA_CTL_DST_TRWID(2) |
667 					DMA_CTL_INT_EN |
668 					DMA_CTL_LLP_SRCEN |
669 					DMA_CTL_LLP_DSTEN);
670 			}
671 
672 			dev_dbg(host_pvt.dwc_dev, "%s setting ctl.high len: "
673 				"0x%08x val: 0x%08x\n", __func__,
674 				len, DMA_CTL_BLK_TS(len / 4));
675 
676 			/* Program the LLI CTL high register */
677 			lli[idx].ctl.high = cpu_to_le32(DMA_CTL_BLK_TS\
678 						(len / 4));
679 
680 			/* Program the next pointer.  The next pointer must be
681 			 * the physical address, not the virtual address.
682 			 */
683 			next_llp = (dma_lli + ((idx + 1) * sizeof(struct \
684 							lli)));
685 
686 			/* The last 2 bits encode the list master select. */
687 			next_llp = DMA_LLP_LMS(next_llp, DMA_LLP_AHBMASTER2);
688 
689 			lli[idx].llp = cpu_to_le32(next_llp);
690 			idx++;
691 			sg_len -= len;
692 			addr += len;
693 		}
694 	}
695 
696 	/*
697 	 * The last next ptr has to be zero and the last control low register
698 	 * has to have LLP_SRC_EN and LLP_DST_EN (linked list pointer source
699 	 * and destination enable) set back to 0 (disabled.) This is what tells
700 	 * the core that this is the last item in the linked list.
701 	 */
702 	if (idx) {
703 		lli[idx-1].llp = 0x00000000;
704 		lli[idx-1].ctl.low &= DMA_CTL_LLP_DISABLE_LE32;
705 
706 		/* Flush cache to memory */
707 		dma_cache_sync(NULL, lli, (sizeof(struct lli) * idx),
708 			       DMA_BIDIRECTIONAL);
709 	}
710 
711 	return idx;
712 }
713 
714 /*
715  * Function: dma_dwc_xfer_start
716  * arguments: Channel number
717  * Return : None
718  * Enables the DMA channel
719  */
720 static void dma_dwc_xfer_start(int dma_ch)
721 {
722 	/* Enable the DMA channel */
723 	out_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low),
724 		 in_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low)) |
725 		 DMA_ENABLE_CHAN(dma_ch));
726 }
727 
728 static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
729 			      struct lli *lli, dma_addr_t dma_lli,
730 			      void __iomem *addr, int dir)
731 {
732 	int dma_ch;
733 	int num_lli;
734 	/* Acquire DMA channel */
735 	dma_ch = dma_request_channel();
736 	if (dma_ch == -1) {
737 		dev_err(host_pvt.dwc_dev, "%s: dma channel unavailable\n",
738 			 __func__);
739 		return -EAGAIN;
740 	}
741 
742 	/* Convert SG list to linked list of items (LLIs) for AHB DMA */
743 	num_lli = map_sg_to_lli(sg, num_elems, lli, dma_lli, addr, dir);
744 
745 	dev_dbg(host_pvt.dwc_dev, "%s sg: 0x%p, count: %d lli: %p dma_lli:"
746 		" 0x%0xlx addr: %p lli count: %d\n", __func__, sg, num_elems,
747 		 lli, (u32)dma_lli, addr, num_lli);
748 
749 	clear_chan_interrupts(dma_ch);
750 
751 	/* Program the CFG register. */
752 	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].cfg.high),
753 		 DMA_CFG_HW_HS_SRC(dma_ch) | DMA_CFG_HW_HS_DEST(dma_ch) |
754 		 DMA_CFG_PROTCTL | DMA_CFG_FCMOD_REQ);
755 	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].cfg.low),
756 		 DMA_CFG_HW_CH_PRIOR(dma_ch));
757 
758 	/* Program the address of the linked list */
759 	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].llp.low),
760 		 DMA_LLP_LMS(dma_lli, DMA_LLP_AHBMASTER2));
761 
762 	/* Program the CTL register with src enable / dst enable */
763 	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].ctl.low),
764 		 DMA_CTL_LLP_SRCEN | DMA_CTL_LLP_DSTEN);
765 	return dma_ch;
766 }
767 
768 /*
769  * Function: dma_dwc_exit
770  * arguments: None
771  * returns status
772  * This function exits the SATA DMA driver
773  */
774 static void dma_dwc_exit(struct sata_dwc_device *hsdev)
775 {
776 	dev_dbg(host_pvt.dwc_dev, "%s:\n", __func__);
777 	if (host_pvt.sata_dma_regs) {
778 		iounmap(host_pvt.sata_dma_regs);
779 		host_pvt.sata_dma_regs = NULL;
780 	}
781 
782 	if (hsdev->irq_dma) {
783 		free_irq(hsdev->irq_dma, hsdev);
784 		hsdev->irq_dma = 0;
785 	}
786 }
787 
788 /*
789  * Function: dma_dwc_init
790  * arguments: hsdev
791  * returns status
792  * This function initializes the SATA DMA driver
793  */
794 static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq)
795 {
796 	int err;
797 
798 	err = dma_request_interrupts(hsdev, irq);
799 	if (err) {
800 		dev_err(host_pvt.dwc_dev, "%s: dma_request_interrupts returns"
801 			" %d\n", __func__, err);
802 		goto error_out;
803 	}
804 
805 	/* Enabe DMA */
806 	out_le32(&(host_pvt.sata_dma_regs->dma_cfg.low), DMA_EN);
807 
808 	dev_notice(host_pvt.dwc_dev, "DMA initialized\n");
809 	dev_dbg(host_pvt.dwc_dev, "SATA DMA registers=0x%p\n", host_pvt.\
810 		sata_dma_regs);
811 
812 	return 0;
813 
814 error_out:
815 	dma_dwc_exit(hsdev);
816 
817 	return err;
818 }
819 
820 static int sata_dwc_scr_read(struct ata_link *link, unsigned int scr, u32 *val)
821 {
822 	if (scr > SCR_NOTIFICATION) {
823 		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
824 			__func__, scr);
825 		return -EINVAL;
826 	}
827 
828 	*val = in_le32((void *)link->ap->ioaddr.scr_addr + (scr * 4));
829 	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=val=0x%08x\n",
830 		__func__, link->ap->print_id, scr, *val);
831 
832 	return 0;
833 }
834 
835 static int sata_dwc_scr_write(struct ata_link *link, unsigned int scr, u32 val)
836 {
837 	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=val=0x%08x\n",
838 		__func__, link->ap->print_id, scr, val);
839 	if (scr > SCR_NOTIFICATION) {
840 		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
841 			 __func__, scr);
842 		return -EINVAL;
843 	}
844 	out_le32((void *)link->ap->ioaddr.scr_addr + (scr * 4), val);
845 
846 	return 0;
847 }
848 
849 static u32 core_scr_read(unsigned int scr)
850 {
851 	return in_le32((void __iomem *)(host_pvt.scr_addr_sstatus) +\
852 			(scr * 4));
853 }
854 
855 static void core_scr_write(unsigned int scr, u32 val)
856 {
857 	out_le32((void __iomem *)(host_pvt.scr_addr_sstatus) + (scr * 4),
858 		val);
859 }
860 
861 static void clear_serror(void)
862 {
863 	u32 val;
864 	val = core_scr_read(SCR_ERROR);
865 	core_scr_write(SCR_ERROR, val);
866 
867 }
868 
869 static void clear_interrupt_bit(struct sata_dwc_device *hsdev, u32 bit)
870 {
871 	out_le32(&hsdev->sata_dwc_regs->intpr,
872 		 in_le32(&hsdev->sata_dwc_regs->intpr));
873 }
874 
875 static u32 qcmd_tag_to_mask(u8 tag)
876 {
877 	return 0x00000001 << (tag & 0x1f);
878 }
879 
880 /* See ahci.c */
881 static void sata_dwc_error_intr(struct ata_port *ap,
882 				struct sata_dwc_device *hsdev, uint intpr)
883 {
884 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
885 	struct ata_eh_info *ehi = &ap->link.eh_info;
886 	unsigned int err_mask = 0, action = 0;
887 	struct ata_queued_cmd *qc;
888 	u32 serror;
889 	u8 status, tag;
890 	u32 err_reg;
891 
892 	ata_ehi_clear_desc(ehi);
893 
894 	serror = core_scr_read(SCR_ERROR);
895 	status = ap->ops->sff_check_status(ap);
896 
897 	err_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.error.\
898 			low));
899 	tag = ap->link.active_tag;
900 
901 	dev_err(ap->dev, "%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x "
902 		"dma_intp=%d pending=%d issued=%d dma_err_status=0x%08x\n",
903 		__func__, serror, intpr, status, host_pvt.dma_interrupt_count,
904 		hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag], err_reg);
905 
906 	/* Clear error register and interrupt bit */
907 	clear_serror();
908 	clear_interrupt_bit(hsdev, SATA_DWC_INTPR_ERR);
909 
910 	/* This is the only error happening now.  TODO check for exact error */
911 
912 	err_mask |= AC_ERR_HOST_BUS;
913 	action |= ATA_EH_RESET;
914 
915 	/* Pass this on to EH */
916 	ehi->serror |= serror;
917 	ehi->action |= action;
918 
919 	qc = ata_qc_from_tag(ap, tag);
920 	if (qc)
921 		qc->err_mask |= err_mask;
922 	else
923 		ehi->err_mask |= err_mask;
924 
925 	ata_port_abort(ap);
926 }
927 
928 /*
929  * Function : sata_dwc_isr
930  * arguments : irq, void *dev_instance, struct pt_regs *regs
931  * Return value : irqreturn_t - status of IRQ
932  * This Interrupt handler called via port ops registered function.
933  * .irq_handler = sata_dwc_isr
934  */
935 static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)
936 {
937 	struct ata_host *host = (struct ata_host *)dev_instance;
938 	struct sata_dwc_device *hsdev = HSDEV_FROM_HOST(host);
939 	struct ata_port *ap;
940 	struct ata_queued_cmd *qc;
941 	unsigned long flags;
942 	u8 status, tag;
943 	int handled, num_processed, port = 0;
944 	uint intpr, sactive, sactive2, tag_mask;
945 	struct sata_dwc_device_port *hsdevp;
946 	host_pvt.sata_dwc_sactive_issued = 0;
947 
948 	spin_lock_irqsave(&host->lock, flags);
949 
950 	/* Read the interrupt register */
951 	intpr = in_le32(&hsdev->sata_dwc_regs->intpr);
952 
953 	ap = host->ports[port];
954 	hsdevp = HSDEVP_FROM_AP(ap);
955 
956 	dev_dbg(ap->dev, "%s intpr=0x%08x active_tag=%d\n", __func__, intpr,
957 		ap->link.active_tag);
958 
959 	/* Check for error interrupt */
960 	if (intpr & SATA_DWC_INTPR_ERR) {
961 		sata_dwc_error_intr(ap, hsdev, intpr);
962 		handled = 1;
963 		goto DONE;
964 	}
965 
966 	/* Check for DMA SETUP FIS (FP DMA) interrupt */
967 	if (intpr & SATA_DWC_INTPR_NEWFP) {
968 		clear_interrupt_bit(hsdev, SATA_DWC_INTPR_NEWFP);
969 
970 		tag = (u8)(in_le32(&hsdev->sata_dwc_regs->fptagr));
971 		dev_dbg(ap->dev, "%s: NEWFP tag=%d\n", __func__, tag);
972 		if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_PEND)
973 			dev_warn(ap->dev, "CMD tag=%d not pending?\n", tag);
974 
975 		host_pvt.sata_dwc_sactive_issued |= qcmd_tag_to_mask(tag);
976 
977 		qc = ata_qc_from_tag(ap, tag);
978 		/*
979 		 * Start FP DMA for NCQ command.  At this point the tag is the
980 		 * active tag.  It is the tag that matches the command about to
981 		 * be completed.
982 		 */
983 		qc->ap->link.active_tag = tag;
984 		sata_dwc_bmdma_start_by_tag(qc, tag);
985 
986 		handled = 1;
987 		goto DONE;
988 	}
989 	sactive = core_scr_read(SCR_ACTIVE);
990 	tag_mask = (host_pvt.sata_dwc_sactive_issued | sactive) ^ sactive;
991 
992 	/* If no sactive issued and tag_mask is zero then this is not NCQ */
993 	if (host_pvt.sata_dwc_sactive_issued == 0 && tag_mask == 0) {
994 		if (ap->link.active_tag == ATA_TAG_POISON)
995 			tag = 0;
996 		else
997 			tag = ap->link.active_tag;
998 		qc = ata_qc_from_tag(ap, tag);
999 
1000 		/* DEV interrupt w/ no active qc? */
1001 		if (unlikely(!qc || (qc->tf.flags & ATA_TFLAG_POLLING))) {
1002 			dev_err(ap->dev, "%s interrupt with no active qc "
1003 				"qc=%p\n", __func__, qc);
1004 			ap->ops->sff_check_status(ap);
1005 			handled = 1;
1006 			goto DONE;
1007 		}
1008 		status = ap->ops->sff_check_status(ap);
1009 
1010 		qc->ap->link.active_tag = tag;
1011 		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
1012 
1013 		if (status & ATA_ERR) {
1014 			dev_dbg(ap->dev, "interrupt ATA_ERR (0x%x)\n", status);
1015 			sata_dwc_qc_complete(ap, qc, 1);
1016 			handled = 1;
1017 			goto DONE;
1018 		}
1019 
1020 		dev_dbg(ap->dev, "%s non-NCQ cmd interrupt, protocol: %s\n",
1021 			__func__, get_prot_descript(qc->tf.protocol));
1022 DRVSTILLBUSY:
1023 		if (ata_is_dma(qc->tf.protocol)) {
1024 			/*
1025 			 * Each DMA transaction produces 2 interrupts. The DMAC
1026 			 * transfer complete interrupt and the SATA controller
1027 			 * operation done interrupt. The command should be
1028 			 * completed only after both interrupts are seen.
1029 			 */
1030 			host_pvt.dma_interrupt_count++;
1031 			if (hsdevp->dma_pending[tag] == \
1032 					SATA_DWC_DMA_PENDING_NONE) {
1033 				dev_err(ap->dev, "%s: DMA not pending "
1034 					"intpr=0x%08x status=0x%08x pending"
1035 					"=%d\n", __func__, intpr, status,
1036 					hsdevp->dma_pending[tag]);
1037 			}
1038 
1039 			if ((host_pvt.dma_interrupt_count % 2) == 0)
1040 				sata_dwc_dma_xfer_complete(ap, 1);
1041 		} else if (ata_is_pio(qc->tf.protocol)) {
1042 			ata_sff_hsm_move(ap, qc, status, 0);
1043 			handled = 1;
1044 			goto DONE;
1045 		} else {
1046 			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
1047 				goto DRVSTILLBUSY;
1048 		}
1049 
1050 		handled = 1;
1051 		goto DONE;
1052 	}
1053 
1054 	/*
1055 	 * This is a NCQ command. At this point we need to figure out for which
1056 	 * tags we have gotten a completion interrupt.  One interrupt may serve
1057 	 * as completion for more than one operation when commands are queued
1058 	 * (NCQ).  We need to process each completed command.
1059 	 */
1060 
1061 	 /* process completed commands */
1062 	sactive = core_scr_read(SCR_ACTIVE);
1063 	tag_mask = (host_pvt.sata_dwc_sactive_issued | sactive) ^ sactive;
1064 
1065 	if (sactive != 0 || (host_pvt.sata_dwc_sactive_issued) > 1 || \
1066 							tag_mask > 1) {
1067 		dev_dbg(ap->dev, "%s NCQ:sactive=0x%08x  sactive_issued=0x%08x"
1068 			"tag_mask=0x%08x\n", __func__, sactive,
1069 			host_pvt.sata_dwc_sactive_issued, tag_mask);
1070 	}
1071 
1072 	if ((tag_mask | (host_pvt.sata_dwc_sactive_issued)) != \
1073 					(host_pvt.sata_dwc_sactive_issued)) {
1074 		dev_warn(ap->dev, "Bad tag mask?  sactive=0x%08x "
1075 			 "(host_pvt.sata_dwc_sactive_issued)=0x%08x  tag_mask"
1076 			 "=0x%08x\n", sactive, host_pvt.sata_dwc_sactive_issued,
1077 			  tag_mask);
1078 	}
1079 
1080 	/* read just to clear ... not bad if currently still busy */
1081 	status = ap->ops->sff_check_status(ap);
1082 	dev_dbg(ap->dev, "%s ATA status register=0x%x\n", __func__, status);
1083 
1084 	tag = 0;
1085 	num_processed = 0;
1086 	while (tag_mask) {
1087 		num_processed++;
1088 		while (!(tag_mask & 0x00000001)) {
1089 			tag++;
1090 			tag_mask <<= 1;
1091 		}
1092 
1093 		tag_mask &= (~0x00000001);
1094 		qc = ata_qc_from_tag(ap, tag);
1095 
1096 		/* To be picked up by completion functions */
1097 		qc->ap->link.active_tag = tag;
1098 		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
1099 
1100 		/* Let libata/scsi layers handle error */
1101 		if (status & ATA_ERR) {
1102 			dev_dbg(ap->dev, "%s ATA_ERR (0x%x)\n", __func__,
1103 				status);
1104 			sata_dwc_qc_complete(ap, qc, 1);
1105 			handled = 1;
1106 			goto DONE;
1107 		}
1108 
1109 		/* Process completed command */
1110 		dev_dbg(ap->dev, "%s NCQ command, protocol: %s\n", __func__,
1111 			get_prot_descript(qc->tf.protocol));
1112 		if (ata_is_dma(qc->tf.protocol)) {
1113 			host_pvt.dma_interrupt_count++;
1114 			if (hsdevp->dma_pending[tag] == \
1115 					SATA_DWC_DMA_PENDING_NONE)
1116 				dev_warn(ap->dev, "%s: DMA not pending?\n",
1117 					__func__);
1118 			if ((host_pvt.dma_interrupt_count % 2) == 0)
1119 				sata_dwc_dma_xfer_complete(ap, 1);
1120 		} else {
1121 			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
1122 				goto STILLBUSY;
1123 		}
1124 		continue;
1125 
1126 STILLBUSY:
1127 		ap->stats.idle_irq++;
1128 		dev_warn(ap->dev, "STILL BUSY IRQ ata%d: irq trap\n",
1129 			ap->print_id);
1130 	} /* while tag_mask */
1131 
1132 	/*
1133 	 * Check to see if any commands completed while we were processing our
1134 	 * initial set of completed commands (read status clears interrupts,
1135 	 * so we might miss a completed command interrupt if one came in while
1136 	 * we were processing --we read status as part of processing a completed
1137 	 * command).
1138 	 */
1139 	sactive2 = core_scr_read(SCR_ACTIVE);
1140 	if (sactive2 != sactive) {
1141 		dev_dbg(ap->dev, "More completed - sactive=0x%x sactive2"
1142 			"=0x%x\n", sactive, sactive2);
1143 	}
1144 	handled = 1;
1145 
1146 DONE:
1147 	spin_unlock_irqrestore(&host->lock, flags);
1148 	return IRQ_RETVAL(handled);
1149 }
1150 
1151 static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag)
1152 {
1153 	struct sata_dwc_device *hsdev = HSDEV_FROM_HSDEVP(hsdevp);
1154 
1155 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX) {
1156 		out_le32(&(hsdev->sata_dwc_regs->dmacr),
1157 			 SATA_DWC_DMACR_RX_CLEAR(
1158 				 in_le32(&(hsdev->sata_dwc_regs->dmacr))));
1159 	} else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX) {
1160 		out_le32(&(hsdev->sata_dwc_regs->dmacr),
1161 			 SATA_DWC_DMACR_TX_CLEAR(
1162 				 in_le32(&(hsdev->sata_dwc_regs->dmacr))));
1163 	} else {
1164 		/*
1165 		 * This should not happen, it indicates the driver is out of
1166 		 * sync.  If it does happen, clear dmacr anyway.
1167 		 */
1168 		dev_err(host_pvt.dwc_dev, "%s DMA protocol RX and"
1169 			"TX DMA not pending tag=0x%02x pending=%d"
1170 			" dmacr: 0x%08x\n", __func__, tag,
1171 			hsdevp->dma_pending[tag],
1172 			in_le32(&(hsdev->sata_dwc_regs->dmacr)));
1173 		out_le32(&(hsdev->sata_dwc_regs->dmacr),
1174 			SATA_DWC_DMACR_TXRXCH_CLEAR);
1175 	}
1176 }
1177 
1178 static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status)
1179 {
1180 	struct ata_queued_cmd *qc;
1181 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1182 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
1183 	u8 tag = 0;
1184 
1185 	tag = ap->link.active_tag;
1186 	qc = ata_qc_from_tag(ap, tag);
1187 	if (!qc) {
1188 		dev_err(ap->dev, "failed to get qc");
1189 		return;
1190 	}
1191 
1192 #ifdef DEBUG_NCQ
1193 	if (tag > 0) {
1194 		dev_info(ap->dev, "%s tag=%u cmd=0x%02x dma dir=%s proto=%s "
1195 			 "dmacr=0x%08x\n", __func__, qc->tag, qc->tf.command,
1196 			 get_dma_dir_descript(qc->dma_dir),
1197 			 get_prot_descript(qc->tf.protocol),
1198 			 in_le32(&(hsdev->sata_dwc_regs->dmacr)));
1199 	}
1200 #endif
1201 
1202 	if (ata_is_dma(qc->tf.protocol)) {
1203 		if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_NONE) {
1204 			dev_err(ap->dev, "%s DMA protocol RX and TX DMA not "
1205 				"pending dmacr: 0x%08x\n", __func__,
1206 				in_le32(&(hsdev->sata_dwc_regs->dmacr)));
1207 		}
1208 
1209 		hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_NONE;
1210 		sata_dwc_qc_complete(ap, qc, check_status);
1211 		ap->link.active_tag = ATA_TAG_POISON;
1212 	} else {
1213 		sata_dwc_qc_complete(ap, qc, check_status);
1214 	}
1215 }
1216 
1217 static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
1218 				u32 check_status)
1219 {
1220 	u8 status = 0;
1221 	u32 mask = 0x0;
1222 	u8 tag = qc->tag;
1223 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1224 	host_pvt.sata_dwc_sactive_queued = 0;
1225 	dev_dbg(ap->dev, "%s checkstatus? %x\n", __func__, check_status);
1226 
1227 	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX)
1228 		dev_err(ap->dev, "TX DMA PENDING\n");
1229 	else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX)
1230 		dev_err(ap->dev, "RX DMA PENDING\n");
1231 	dev_dbg(ap->dev, "QC complete cmd=0x%02x status=0x%02x ata%u:"
1232 		" protocol=%d\n", qc->tf.command, status, ap->print_id,
1233 		 qc->tf.protocol);
1234 
1235 	/* clear active bit */
1236 	mask = (~(qcmd_tag_to_mask(tag)));
1237 	host_pvt.sata_dwc_sactive_queued = (host_pvt.sata_dwc_sactive_queued) \
1238 						& mask;
1239 	host_pvt.sata_dwc_sactive_issued = (host_pvt.sata_dwc_sactive_issued) \
1240 						& mask;
1241 	ata_qc_complete(qc);
1242 	return 0;
1243 }
1244 
1245 static void sata_dwc_enable_interrupts(struct sata_dwc_device *hsdev)
1246 {
1247 	/* Enable selective interrupts by setting the interrupt maskregister*/
1248 	out_le32(&hsdev->sata_dwc_regs->intmr,
1249 		 SATA_DWC_INTMR_ERRM |
1250 		 SATA_DWC_INTMR_NEWFPM |
1251 		 SATA_DWC_INTMR_PMABRTM |
1252 		 SATA_DWC_INTMR_DMATM);
1253 	/*
1254 	 * Unmask the error bits that should trigger an error interrupt by
1255 	 * setting the error mask register.
1256 	 */
1257 	out_le32(&hsdev->sata_dwc_regs->errmr, SATA_DWC_SERROR_ERR_BITS);
1258 
1259 	dev_dbg(host_pvt.dwc_dev, "%s: INTMR = 0x%08x, ERRMR = 0x%08x\n",
1260 		 __func__, in_le32(&hsdev->sata_dwc_regs->intmr),
1261 		in_le32(&hsdev->sata_dwc_regs->errmr));
1262 }
1263 
1264 static void sata_dwc_setup_port(struct ata_ioports *port, unsigned long base)
1265 {
1266 	port->cmd_addr = (void *)base + 0x00;
1267 	port->data_addr = (void *)base + 0x00;
1268 
1269 	port->error_addr = (void *)base + 0x04;
1270 	port->feature_addr = (void *)base + 0x04;
1271 
1272 	port->nsect_addr = (void *)base + 0x08;
1273 
1274 	port->lbal_addr = (void *)base + 0x0c;
1275 	port->lbam_addr = (void *)base + 0x10;
1276 	port->lbah_addr = (void *)base + 0x14;
1277 
1278 	port->device_addr = (void *)base + 0x18;
1279 	port->command_addr = (void *)base + 0x1c;
1280 	port->status_addr = (void *)base + 0x1c;
1281 
1282 	port->altstatus_addr = (void *)base + 0x20;
1283 	port->ctl_addr = (void *)base + 0x20;
1284 }
1285 
1286 /*
1287  * Function : sata_dwc_port_start
1288  * arguments : struct ata_ioports *port
1289  * Return value : returns 0 if success, error code otherwise
1290  * This function allocates the scatter gather LLI table for AHB DMA
1291  */
1292 static int sata_dwc_port_start(struct ata_port *ap)
1293 {
1294 	int err = 0;
1295 	struct sata_dwc_device *hsdev;
1296 	struct sata_dwc_device_port *hsdevp = NULL;
1297 	struct device *pdev;
1298 	int i;
1299 
1300 	hsdev = HSDEV_FROM_AP(ap);
1301 
1302 	dev_dbg(ap->dev, "%s: port_no=%d\n", __func__, ap->port_no);
1303 
1304 	hsdev->host = ap->host;
1305 	pdev = ap->host->dev;
1306 	if (!pdev) {
1307 		dev_err(ap->dev, "%s: no ap->host->dev\n", __func__);
1308 		err = -ENODEV;
1309 		goto CLEANUP;
1310 	}
1311 
1312 	/* Allocate Port Struct */
1313 	hsdevp = kzalloc(sizeof(*hsdevp), GFP_KERNEL);
1314 	if (!hsdevp) {
1315 		dev_err(ap->dev, "%s: kmalloc failed for hsdevp\n", __func__);
1316 		err = -ENOMEM;
1317 		goto CLEANUP;
1318 	}
1319 	hsdevp->hsdev = hsdev;
1320 
1321 	for (i = 0; i < SATA_DWC_QCMD_MAX; i++)
1322 		hsdevp->cmd_issued[i] = SATA_DWC_CMD_ISSUED_NOT;
1323 
1324 	ap->bmdma_prd = 0;	/* set these so libata doesn't use them */
1325 	ap->bmdma_prd_dma = 0;
1326 
1327 	/*
1328 	 * DMA - Assign scatter gather LLI table. We can't use the libata
1329 	 * version since it's PRD is IDE PCI specific.
1330 	 */
1331 	for (i = 0; i < SATA_DWC_QCMD_MAX; i++) {
1332 		hsdevp->llit[i] = dma_alloc_coherent(pdev,
1333 						     SATA_DWC_DMAC_LLI_TBL_SZ,
1334 						     &(hsdevp->llit_dma[i]),
1335 						     GFP_ATOMIC);
1336 		if (!hsdevp->llit[i]) {
1337 			dev_err(ap->dev, "%s: dma_alloc_coherent failed\n",
1338 				 __func__);
1339 			err = -ENOMEM;
1340 			goto CLEANUP_ALLOC;
1341 		}
1342 	}
1343 
1344 	if (ap->port_no == 0)  {
1345 		dev_dbg(ap->dev, "%s: clearing TXCHEN, RXCHEN in DMAC\n",
1346 			__func__);
1347 		out_le32(&hsdev->sata_dwc_regs->dmacr,
1348 			 SATA_DWC_DMACR_TXRXCH_CLEAR);
1349 
1350 		dev_dbg(ap->dev, "%s: setting burst size in DBTSR\n",
1351 			 __func__);
1352 		out_le32(&hsdev->sata_dwc_regs->dbtsr,
1353 			 (SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
1354 			  SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT)));
1355 	}
1356 
1357 	/* Clear any error bits before libata starts issuing commands */
1358 	clear_serror();
1359 	ap->private_data = hsdevp;
1360 	dev_dbg(ap->dev, "%s: done\n", __func__);
1361 	return 0;
1362 
1363 CLEANUP_ALLOC:
1364 	kfree(hsdevp);
1365 CLEANUP:
1366 	dev_dbg(ap->dev, "%s: fail. ap->id = %d\n", __func__, ap->print_id);
1367 	return err;
1368 }
1369 
1370 static void sata_dwc_port_stop(struct ata_port *ap)
1371 {
1372 	int i;
1373 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
1374 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1375 
1376 	dev_dbg(ap->dev, "%s: ap->id = %d\n", __func__, ap->print_id);
1377 
1378 	if (hsdevp && hsdev) {
1379 		/* deallocate LLI table */
1380 		for (i = 0; i < SATA_DWC_QCMD_MAX; i++) {
1381 			dma_free_coherent(ap->host->dev,
1382 					  SATA_DWC_DMAC_LLI_TBL_SZ,
1383 					 hsdevp->llit[i], hsdevp->llit_dma[i]);
1384 		}
1385 
1386 		kfree(hsdevp);
1387 	}
1388 	ap->private_data = NULL;
1389 }
1390 
1391 /*
1392  * Function : sata_dwc_exec_command_by_tag
1393  * arguments : ata_port *ap, ata_taskfile *tf, u8 tag, u32 cmd_issued
1394  * Return value : None
1395  * This function keeps track of individual command tag ids and calls
1396  * ata_exec_command in libata
1397  */
1398 static void sata_dwc_exec_command_by_tag(struct ata_port *ap,
1399 					 struct ata_taskfile *tf,
1400 					 u8 tag, u32 cmd_issued)
1401 {
1402 	unsigned long flags;
1403 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1404 
1405 	dev_dbg(ap->dev, "%s cmd(0x%02x): %s tag=%d\n", __func__, tf->command,
1406 		ata_get_cmd_descript(tf->command), tag);
1407 
1408 	spin_lock_irqsave(&ap->host->lock, flags);
1409 	hsdevp->cmd_issued[tag] = cmd_issued;
1410 	spin_unlock_irqrestore(&ap->host->lock, flags);
1411 	/*
1412 	 * Clear SError before executing a new command.
1413 	 * sata_dwc_scr_write and read can not be used here. Clearing the PM
1414 	 * managed SError register for the disk needs to be done before the
1415 	 * task file is loaded.
1416 	 */
1417 	clear_serror();
1418 	ata_sff_exec_command(ap, tf);
1419 }
1420 
1421 static void sata_dwc_bmdma_setup_by_tag(struct ata_queued_cmd *qc, u8 tag)
1422 {
1423 	sata_dwc_exec_command_by_tag(qc->ap, &qc->tf, tag,
1424 				     SATA_DWC_CMD_ISSUED_PEND);
1425 }
1426 
1427 static void sata_dwc_bmdma_setup(struct ata_queued_cmd *qc)
1428 {
1429 	u8 tag = qc->tag;
1430 
1431 	if (ata_is_ncq(qc->tf.protocol)) {
1432 		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
1433 			__func__, qc->ap->link.sactive, tag);
1434 	} else {
1435 		tag = 0;
1436 	}
1437 	sata_dwc_bmdma_setup_by_tag(qc, tag);
1438 }
1439 
1440 static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag)
1441 {
1442 	int start_dma;
1443 	u32 reg, dma_chan;
1444 	struct sata_dwc_device *hsdev = HSDEV_FROM_QC(qc);
1445 	struct ata_port *ap = qc->ap;
1446 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1447 	int dir = qc->dma_dir;
1448 	dma_chan = hsdevp->dma_chan[tag];
1449 
1450 	if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_NOT) {
1451 		start_dma = 1;
1452 		if (dir == DMA_TO_DEVICE)
1453 			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_TX;
1454 		else
1455 			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_RX;
1456 	} else {
1457 		dev_err(ap->dev, "%s: Command not pending cmd_issued=%d "
1458 			"(tag=%d) DMA NOT started\n", __func__,
1459 			hsdevp->cmd_issued[tag], tag);
1460 		start_dma = 0;
1461 	}
1462 
1463 	dev_dbg(ap->dev, "%s qc=%p tag: %x cmd: 0x%02x dma_dir: %s "
1464 		"start_dma? %x\n", __func__, qc, tag, qc->tf.command,
1465 		get_dma_dir_descript(qc->dma_dir), start_dma);
1466 	sata_dwc_tf_dump(&(qc->tf));
1467 
1468 	if (start_dma) {
1469 		reg = core_scr_read(SCR_ERROR);
1470 		if (reg & SATA_DWC_SERROR_ERR_BITS) {
1471 			dev_err(ap->dev, "%s: ****** SError=0x%08x ******\n",
1472 				__func__, reg);
1473 		}
1474 
1475 		if (dir == DMA_TO_DEVICE)
1476 			out_le32(&hsdev->sata_dwc_regs->dmacr,
1477 				SATA_DWC_DMACR_TXCHEN);
1478 		else
1479 			out_le32(&hsdev->sata_dwc_regs->dmacr,
1480 				SATA_DWC_DMACR_RXCHEN);
1481 
1482 		/* Enable AHB DMA transfer on the specified channel */
1483 		dma_dwc_xfer_start(dma_chan);
1484 	}
1485 }
1486 
1487 static void sata_dwc_bmdma_start(struct ata_queued_cmd *qc)
1488 {
1489 	u8 tag = qc->tag;
1490 
1491 	if (ata_is_ncq(qc->tf.protocol)) {
1492 		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
1493 			__func__, qc->ap->link.sactive, tag);
1494 	} else {
1495 		tag = 0;
1496 	}
1497 	dev_dbg(qc->ap->dev, "%s\n", __func__);
1498 	sata_dwc_bmdma_start_by_tag(qc, tag);
1499 }
1500 
1501 /*
1502  * Function : sata_dwc_qc_prep_by_tag
1503  * arguments : ata_queued_cmd *qc, u8 tag
1504  * Return value : None
1505  * qc_prep for a particular queued command based on tag
1506  */
1507 static void sata_dwc_qc_prep_by_tag(struct ata_queued_cmd *qc, u8 tag)
1508 {
1509 	struct scatterlist *sg = qc->sg;
1510 	struct ata_port *ap = qc->ap;
1511 	int dma_chan;
1512 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
1513 	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
1514 
1515 	dev_dbg(ap->dev, "%s: port=%d dma dir=%s n_elem=%d\n",
1516 		__func__, ap->port_no, get_dma_dir_descript(qc->dma_dir),
1517 		 qc->n_elem);
1518 
1519 	dma_chan = dma_dwc_xfer_setup(sg, qc->n_elem, hsdevp->llit[tag],
1520 				      hsdevp->llit_dma[tag],
1521 				      (void *__iomem)(&hsdev->sata_dwc_regs->\
1522 				      dmadr), qc->dma_dir);
1523 	if (dma_chan < 0) {
1524 		dev_err(ap->dev, "%s: dma_dwc_xfer_setup returns err %d\n",
1525 			__func__, dma_chan);
1526 		return;
1527 	}
1528 	hsdevp->dma_chan[tag] = dma_chan;
1529 }
1530 
1531 static unsigned int sata_dwc_qc_issue(struct ata_queued_cmd *qc)
1532 {
1533 	u32 sactive;
1534 	u8 tag = qc->tag;
1535 	struct ata_port *ap = qc->ap;
1536 
1537 #ifdef DEBUG_NCQ
1538 	if (qc->tag > 0 || ap->link.sactive > 1)
1539 		dev_info(ap->dev, "%s ap id=%d cmd(0x%02x)=%s qc tag=%d "
1540 			 "prot=%s ap active_tag=0x%08x ap sactive=0x%08x\n",
1541 			 __func__, ap->print_id, qc->tf.command,
1542 			 ata_get_cmd_descript(qc->tf.command),
1543 			 qc->tag, get_prot_descript(qc->tf.protocol),
1544 			 ap->link.active_tag, ap->link.sactive);
1545 #endif
1546 
1547 	if (!ata_is_ncq(qc->tf.protocol))
1548 		tag = 0;
1549 	sata_dwc_qc_prep_by_tag(qc, tag);
1550 
1551 	if (ata_is_ncq(qc->tf.protocol)) {
1552 		sactive = core_scr_read(SCR_ACTIVE);
1553 		sactive |= (0x00000001 << tag);
1554 		core_scr_write(SCR_ACTIVE, sactive);
1555 
1556 		dev_dbg(qc->ap->dev, "%s: tag=%d ap->link.sactive = 0x%08x "
1557 			"sactive=0x%08x\n", __func__, tag, qc->ap->link.sactive,
1558 			sactive);
1559 
1560 		ap->ops->sff_tf_load(ap, &qc->tf);
1561 		sata_dwc_exec_command_by_tag(ap, &qc->tf, qc->tag,
1562 					     SATA_DWC_CMD_ISSUED_PEND);
1563 	} else {
1564 		ata_sff_qc_issue(qc);
1565 	}
1566 	return 0;
1567 }
1568 
1569 /*
1570  * Function : sata_dwc_qc_prep
1571  * arguments : ata_queued_cmd *qc
1572  * Return value : None
1573  * qc_prep for a particular queued command
1574  */
1575 
1576 static void sata_dwc_qc_prep(struct ata_queued_cmd *qc)
1577 {
1578 	if ((qc->dma_dir == DMA_NONE) || (qc->tf.protocol == ATA_PROT_PIO))
1579 		return;
1580 
1581 #ifdef DEBUG_NCQ
1582 	if (qc->tag > 0)
1583 		dev_info(qc->ap->dev, "%s: qc->tag=%d ap->active_tag=0x%08x\n",
1584 			 __func__, qc->tag, qc->ap->link.active_tag);
1585 
1586 	return ;
1587 #endif
1588 }
1589 
1590 static void sata_dwc_error_handler(struct ata_port *ap)
1591 {
1592 	ata_sff_error_handler(ap);
1593 }
1594 
1595 int sata_dwc_hardreset(struct ata_link *link, unsigned int *class,
1596 			unsigned long deadline)
1597 {
1598 	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(link->ap);
1599 	int ret;
1600 
1601 	ret = sata_sff_hardreset(link, class, deadline);
1602 
1603 	sata_dwc_enable_interrupts(hsdev);
1604 
1605 	/* Reconfigure the DMA control register */
1606 	out_le32(&hsdev->sata_dwc_regs->dmacr,
1607 		 SATA_DWC_DMACR_TXRXCH_CLEAR);
1608 
1609 	/* Reconfigure the DMA Burst Transaction Size register */
1610 	out_le32(&hsdev->sata_dwc_regs->dbtsr,
1611 		 SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
1612 		 SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT));
1613 
1614 	return ret;
1615 }
1616 
1617 /*
1618  * scsi mid-layer and libata interface structures
1619  */
1620 static struct scsi_host_template sata_dwc_sht = {
1621 	ATA_NCQ_SHT(DRV_NAME),
1622 	/*
1623 	 * test-only: Currently this driver doesn't handle NCQ
1624 	 * correctly. We enable NCQ but set the queue depth to a
1625 	 * max of 1. This will get fixed in in a future release.
1626 	 */
1627 	.sg_tablesize		= LIBATA_MAX_PRD,
1628 	.can_queue		= ATA_DEF_QUEUE,	/* ATA_MAX_QUEUE */
1629 	.dma_boundary		= ATA_DMA_BOUNDARY,
1630 };
1631 
1632 static struct ata_port_operations sata_dwc_ops = {
1633 	.inherits		= &ata_sff_port_ops,
1634 
1635 	.error_handler		= sata_dwc_error_handler,
1636 	.hardreset		= sata_dwc_hardreset,
1637 
1638 	.qc_prep		= sata_dwc_qc_prep,
1639 	.qc_issue		= sata_dwc_qc_issue,
1640 
1641 	.scr_read		= sata_dwc_scr_read,
1642 	.scr_write		= sata_dwc_scr_write,
1643 
1644 	.port_start		= sata_dwc_port_start,
1645 	.port_stop		= sata_dwc_port_stop,
1646 
1647 	.bmdma_setup		= sata_dwc_bmdma_setup,
1648 	.bmdma_start		= sata_dwc_bmdma_start,
1649 };
1650 
1651 static const struct ata_port_info sata_dwc_port_info[] = {
1652 	{
1653 		.flags		= ATA_FLAG_SATA | ATA_FLAG_NCQ,
1654 		.pio_mask	= ATA_PIO4,
1655 		.udma_mask	= ATA_UDMA6,
1656 		.port_ops	= &sata_dwc_ops,
1657 	},
1658 };
1659 
1660 static int sata_dwc_probe(struct platform_device *ofdev)
1661 {
1662 	struct sata_dwc_device *hsdev;
1663 	u32 idr, versionr;
1664 	char *ver = (char *)&versionr;
1665 	u8 *base = NULL;
1666 	int err = 0;
1667 	int irq, rc;
1668 	struct ata_host *host;
1669 	struct ata_port_info pi = sata_dwc_port_info[0];
1670 	const struct ata_port_info *ppi[] = { &pi, NULL };
1671 	struct device_node *np = ofdev->dev.of_node;
1672 	u32 dma_chan;
1673 
1674 	/* Allocate DWC SATA device */
1675 	hsdev = kzalloc(sizeof(*hsdev), GFP_KERNEL);
1676 	if (hsdev == NULL) {
1677 		dev_err(&ofdev->dev, "kmalloc failed for hsdev\n");
1678 		err = -ENOMEM;
1679 		goto error;
1680 	}
1681 
1682 	if (of_property_read_u32(np, "dma-channel", &dma_chan)) {
1683 		dev_warn(&ofdev->dev, "no dma-channel property set."
1684 			 " Use channel 0\n");
1685 		dma_chan = 0;
1686 	}
1687 	host_pvt.dma_channel = dma_chan;
1688 
1689 	/* Ioremap SATA registers */
1690 	base = of_iomap(ofdev->dev.of_node, 0);
1691 	if (!base) {
1692 		dev_err(&ofdev->dev, "ioremap failed for SATA register"
1693 			" address\n");
1694 		err = -ENODEV;
1695 		goto error_kmalloc;
1696 	}
1697 	hsdev->reg_base = base;
1698 	dev_dbg(&ofdev->dev, "ioremap done for SATA register address\n");
1699 
1700 	/* Synopsys DWC SATA specific Registers */
1701 	hsdev->sata_dwc_regs = (void *__iomem)(base + SATA_DWC_REG_OFFSET);
1702 
1703 	/* Allocate and fill host */
1704 	host = ata_host_alloc_pinfo(&ofdev->dev, ppi, SATA_DWC_MAX_PORTS);
1705 	if (!host) {
1706 		dev_err(&ofdev->dev, "ata_host_alloc_pinfo failed\n");
1707 		err = -ENOMEM;
1708 		goto error_iomap;
1709 	}
1710 
1711 	host->private_data = hsdev;
1712 
1713 	/* Setup port */
1714 	host->ports[0]->ioaddr.cmd_addr = base;
1715 	host->ports[0]->ioaddr.scr_addr = base + SATA_DWC_SCR_OFFSET;
1716 	host_pvt.scr_addr_sstatus = base + SATA_DWC_SCR_OFFSET;
1717 	sata_dwc_setup_port(&host->ports[0]->ioaddr, (unsigned long)base);
1718 
1719 	/* Read the ID and Version Registers */
1720 	idr = in_le32(&hsdev->sata_dwc_regs->idr);
1721 	versionr = in_le32(&hsdev->sata_dwc_regs->versionr);
1722 	dev_notice(&ofdev->dev, "id %d, controller version %c.%c%c\n",
1723 		   idr, ver[0], ver[1], ver[2]);
1724 
1725 	/* Get SATA DMA interrupt number */
1726 	irq = irq_of_parse_and_map(ofdev->dev.of_node, 1);
1727 	if (irq == NO_IRQ) {
1728 		dev_err(&ofdev->dev, "no SATA DMA irq\n");
1729 		err = -ENODEV;
1730 		goto error_out;
1731 	}
1732 
1733 	/* Get physical SATA DMA register base address */
1734 	host_pvt.sata_dma_regs = of_iomap(ofdev->dev.of_node, 1);
1735 	if (!(host_pvt.sata_dma_regs)) {
1736 		dev_err(&ofdev->dev, "ioremap failed for AHBDMA register"
1737 			" address\n");
1738 		err = -ENODEV;
1739 		goto error_out;
1740 	}
1741 
1742 	/* Save dev for later use in dev_xxx() routines */
1743 	host_pvt.dwc_dev = &ofdev->dev;
1744 
1745 	/* Initialize AHB DMAC */
1746 	dma_dwc_init(hsdev, irq);
1747 
1748 	/* Enable SATA Interrupts */
1749 	sata_dwc_enable_interrupts(hsdev);
1750 
1751 	/* Get SATA interrupt number */
1752 	irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
1753 	if (irq == NO_IRQ) {
1754 		dev_err(&ofdev->dev, "no SATA DMA irq\n");
1755 		err = -ENODEV;
1756 		goto error_out;
1757 	}
1758 
1759 	/*
1760 	 * Now, register with libATA core, this will also initiate the
1761 	 * device discovery process, invoking our port_start() handler &
1762 	 * error_handler() to execute a dummy Softreset EH session
1763 	 */
1764 	rc = ata_host_activate(host, irq, sata_dwc_isr, 0, &sata_dwc_sht);
1765 
1766 	if (rc != 0)
1767 		dev_err(&ofdev->dev, "failed to activate host");
1768 
1769 	dev_set_drvdata(&ofdev->dev, host);
1770 	return 0;
1771 
1772 error_out:
1773 	/* Free SATA DMA resources */
1774 	dma_dwc_exit(hsdev);
1775 
1776 error_iomap:
1777 	iounmap(base);
1778 error_kmalloc:
1779 	kfree(hsdev);
1780 error:
1781 	return err;
1782 }
1783 
1784 static int sata_dwc_remove(struct platform_device *ofdev)
1785 {
1786 	struct device *dev = &ofdev->dev;
1787 	struct ata_host *host = dev_get_drvdata(dev);
1788 	struct sata_dwc_device *hsdev = host->private_data;
1789 
1790 	ata_host_detach(host);
1791 	dev_set_drvdata(dev, NULL);
1792 
1793 	/* Free SATA DMA resources */
1794 	dma_dwc_exit(hsdev);
1795 
1796 	iounmap(hsdev->reg_base);
1797 	kfree(hsdev);
1798 	kfree(host);
1799 	dev_dbg(&ofdev->dev, "done\n");
1800 	return 0;
1801 }
1802 
1803 static const struct of_device_id sata_dwc_match[] = {
1804 	{ .compatible = "amcc,sata-460ex", },
1805 	{}
1806 };
1807 MODULE_DEVICE_TABLE(of, sata_dwc_match);
1808 
1809 static struct platform_driver sata_dwc_driver = {
1810 	.driver = {
1811 		.name = DRV_NAME,
1812 		.owner = THIS_MODULE,
1813 		.of_match_table = sata_dwc_match,
1814 	},
1815 	.probe = sata_dwc_probe,
1816 	.remove = sata_dwc_remove,
1817 };
1818 
1819 module_platform_driver(sata_dwc_driver);
1820 
1821 MODULE_LICENSE("GPL");
1822 MODULE_AUTHOR("Mark Miesfeld <mmiesfeld@amcc.com>");
1823 MODULE_DESCRIPTION("DesignWare Cores SATA controller low lever driver");
1824 MODULE_VERSION(DRV_VERSION);
1825