1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Xilinx SystemACE device driver
4 *
5 * Copyright 2007 Secret Lab Technologies Ltd.
6 */
7
8/*
9 * The SystemACE chip is designed to configure FPGAs by loading an FPGA
10 * bitstream from a file on a CF card and squirting it into FPGAs connected
11 * to the SystemACE JTAG chain.  It also has the advantage of providing an
12 * MPU interface which can be used to control the FPGA configuration process
13 * and to use the attached CF card for general purpose storage.
14 *
15 * This driver is a block device driver for the SystemACE.
16 *
17 * Initialization:
18 *    The driver registers itself as a platform_device driver at module
19 *    load time.  The platform bus will take care of calling the
20 *    ace_probe() method for all SystemACE instances in the system.  Any
21 *    number of SystemACE instances are supported.  ace_probe() calls
22 *    ace_setup() which initialized all data structures, reads the CF
23 *    id structure and registers the device.
24 *
25 * Processing:
26 *    Just about all of the heavy lifting in this driver is performed by
27 *    a Finite State Machine (FSM).  The driver needs to wait on a number
28 *    of events; some raised by interrupts, some which need to be polled
29 *    for.  Describing all of the behaviour in a FSM seems to be the
30 *    easiest way to keep the complexity low and make it easy to
31 *    understand what the driver is doing.  If the block ops or the
32 *    request function need to interact with the hardware, then they
33 *    simply need to flag the request and kick of FSM processing.
34 *
35 *    The FSM itself is atomic-safe code which can be run from any
36 *    context.  The general process flow is:
37 *    1. obtain the ace->lock spinlock.
38 *    2. loop on ace_fsm_dostate() until the ace->fsm_continue flag is
39 *       cleared.
40 *    3. release the lock.
41 *
42 *    Individual states do not sleep in any way.  If a condition needs to
43 *    be waited for then the state much clear the fsm_continue flag and
44 *    either schedule the FSM to be run again at a later time, or expect
45 *    an interrupt to call the FSM when the desired condition is met.
46 *
47 *    In normal operation, the FSM is processed at interrupt context
48 *    either when the driver's tasklet is scheduled, or when an irq is
49 *    raised by the hardware.  The tasklet can be scheduled at any time.
50 *    The request method in particular schedules the tasklet when a new
51 *    request has been indicated by the block layer.  Once started, the
52 *    FSM proceeds as far as it can processing the request until it
53 *    needs on a hardware event.  At this point, it must yield execution.
54 *
55 *    A state has two options when yielding execution:
56 *    1. ace_fsm_yield()
57 *       - Call if need to poll for event.
58 *       - clears the fsm_continue flag to exit the processing loop
59 *       - reschedules the tasklet to run again as soon as possible
60 *    2. ace_fsm_yieldirq()
61 *       - Call if an irq is expected from the HW
62 *       - clears the fsm_continue flag to exit the processing loop
63 *       - does not reschedule the tasklet so the FSM will not be processed
64 *         again until an irq is received.
65 *    After calling a yield function, the state must return control back
66 *    to the FSM main loop.
67 *
68 *    Additionally, the driver maintains a kernel timer which can process
69 *    the FSM.  If the FSM gets stalled, typically due to a missed
70 *    interrupt, then the kernel timer will expire and the driver can
71 *    continue where it left off.
72 *
73 * To Do:
74 *    - Add FPGA configuration control interface.
75 *    - Request major number from lanana
76 */
77
78#undef DEBUG
79
80#include <linux/module.h>
81#include <linux/ctype.h>
82#include <linux/init.h>
83#include <linux/interrupt.h>
84#include <linux/errno.h>
85#include <linux/kernel.h>
86#include <linux/delay.h>
87#include <linux/slab.h>
88#include <linux/blk-mq.h>
89#include <linux/mutex.h>
90#include <linux/ata.h>
91#include <linux/hdreg.h>
92#include <linux/platform_device.h>
93#if defined(CONFIG_OF)
94#include <linux/of_address.h>
95#include <linux/of_device.h>
96#include <linux/of_platform.h>
97#endif
98
99MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
100MODULE_DESCRIPTION("Xilinx SystemACE device driver");
101MODULE_LICENSE("GPL");
102
103/* SystemACE register definitions */
104#define ACE_BUSMODE (0x00)
105
106#define ACE_STATUS (0x04)
107#define ACE_STATUS_CFGLOCK      (0x00000001)
108#define ACE_STATUS_MPULOCK      (0x00000002)
109#define ACE_STATUS_CFGERROR     (0x00000004)	/* config controller error */
110#define ACE_STATUS_CFCERROR     (0x00000008)	/* CF controller error */
111#define ACE_STATUS_CFDETECT     (0x00000010)
112#define ACE_STATUS_DATABUFRDY   (0x00000020)
113#define ACE_STATUS_DATABUFMODE  (0x00000040)
114#define ACE_STATUS_CFGDONE      (0x00000080)
115#define ACE_STATUS_RDYFORCFCMD  (0x00000100)
116#define ACE_STATUS_CFGMODEPIN   (0x00000200)
117#define ACE_STATUS_CFGADDR_MASK (0x0000e000)
118#define ACE_STATUS_CFBSY        (0x00020000)
119#define ACE_STATUS_CFRDY        (0x00040000)
120#define ACE_STATUS_CFDWF        (0x00080000)
121#define ACE_STATUS_CFDSC        (0x00100000)
122#define ACE_STATUS_CFDRQ        (0x00200000)
123#define ACE_STATUS_CFCORR       (0x00400000)
124#define ACE_STATUS_CFERR        (0x00800000)
125
126#define ACE_ERROR (0x08)
127#define ACE_CFGLBA (0x0c)
128#define ACE_MPULBA (0x10)
129
130#define ACE_SECCNTCMD (0x14)
131#define ACE_SECCNTCMD_RESET      (0x0100)
132#define ACE_SECCNTCMD_IDENTIFY   (0x0200)
133#define ACE_SECCNTCMD_READ_DATA  (0x0300)
134#define ACE_SECCNTCMD_WRITE_DATA (0x0400)
135#define ACE_SECCNTCMD_ABORT      (0x0600)
136
137#define ACE_VERSION (0x16)
138#define ACE_VERSION_REVISION_MASK (0x00FF)
139#define ACE_VERSION_MINOR_MASK    (0x0F00)
140#define ACE_VERSION_MAJOR_MASK    (0xF000)
141
142#define ACE_CTRL (0x18)
143#define ACE_CTRL_FORCELOCKREQ   (0x0001)
144#define ACE_CTRL_LOCKREQ        (0x0002)
145#define ACE_CTRL_FORCECFGADDR   (0x0004)
146#define ACE_CTRL_FORCECFGMODE   (0x0008)
147#define ACE_CTRL_CFGMODE        (0x0010)
148#define ACE_CTRL_CFGSTART       (0x0020)
149#define ACE_CTRL_CFGSEL         (0x0040)
150#define ACE_CTRL_CFGRESET       (0x0080)
151#define ACE_CTRL_DATABUFRDYIRQ  (0x0100)
152#define ACE_CTRL_ERRORIRQ       (0x0200)
153#define ACE_CTRL_CFGDONEIRQ     (0x0400)
154#define ACE_CTRL_RESETIRQ       (0x0800)
155#define ACE_CTRL_CFGPROG        (0x1000)
156#define ACE_CTRL_CFGADDR_MASK   (0xe000)
157
158#define ACE_FATSTAT (0x1c)
159
160#define ACE_NUM_MINORS 16
161#define ACE_SECTOR_SIZE (512)
162#define ACE_FIFO_SIZE (32)
163#define ACE_BUF_PER_SECTOR (ACE_SECTOR_SIZE / ACE_FIFO_SIZE)
164
165#define ACE_BUS_WIDTH_8  0
166#define ACE_BUS_WIDTH_16 1
167
168struct ace_reg_ops;
169
170struct ace_device {
171	/* driver state data */
172	int id;
173	int media_change;
174	int users;
175	struct list_head list;
176
177	/* finite state machine data */
178	struct tasklet_struct fsm_tasklet;
179	uint fsm_task;		/* Current activity (ACE_TASK_*) */
180	uint fsm_state;		/* Current state (ACE_FSM_STATE_*) */
181	uint fsm_continue_flag;	/* cleared to exit FSM mainloop */
182	uint fsm_iter_num;
183	struct timer_list stall_timer;
184
185	/* Transfer state/result, use for both id and block request */
186	struct request *req;	/* request being processed */
187	void *data_ptr;		/* pointer to I/O buffer */
188	int data_count;		/* number of buffers remaining */
189	int data_result;	/* Result of transfer; 0 := success */
190
191	int id_req_count;	/* count of id requests */
192	int id_result;
193	struct completion id_completion;	/* used when id req finishes */
194	int in_irq;
195
196	/* Details of hardware device */
197	resource_size_t physaddr;
198	void __iomem *baseaddr;
199	int irq;
200	int bus_width;		/* 0 := 8 bit; 1 := 16 bit */
201	struct ace_reg_ops *reg_ops;
202	int lock_count;
203
204	/* Block device data structures */
205	spinlock_t lock;
206	struct device *dev;
207	struct request_queue *queue;
208	struct gendisk *gd;
209	struct blk_mq_tag_set tag_set;
210	struct list_head rq_list;
211
212	/* Inserted CF card parameters */
213	u16 cf_id[ATA_ID_WORDS];
214};
215
216static DEFINE_MUTEX(xsysace_mutex);
217static int ace_major;
218
219/* ---------------------------------------------------------------------
220 * Low level register access
221 */
222
223struct ace_reg_ops {
224	u16(*in) (struct ace_device * ace, int reg);
225	void (*out) (struct ace_device * ace, int reg, u16 val);
226	void (*datain) (struct ace_device * ace);
227	void (*dataout) (struct ace_device * ace);
228};
229
230/* 8 Bit bus width */
231static u16 ace_in_8(struct ace_device *ace, int reg)
232{
233	void __iomem *r = ace->baseaddr + reg;
234	return in_8(r) | (in_8(r + 1) << 8);
235}
236
237static void ace_out_8(struct ace_device *ace, int reg, u16 val)
238{
239	void __iomem *r = ace->baseaddr + reg;
240	out_8(r, val);
241	out_8(r + 1, val >> 8);
242}
243
244static void ace_datain_8(struct ace_device *ace)
245{
246	void __iomem *r = ace->baseaddr + 0x40;
247	u8 *dst = ace->data_ptr;
248	int i = ACE_FIFO_SIZE;
249	while (i--)
250		*dst++ = in_8(r++);
251	ace->data_ptr = dst;
252}
253
254static void ace_dataout_8(struct ace_device *ace)
255{
256	void __iomem *r = ace->baseaddr + 0x40;
257	u8 *src = ace->data_ptr;
258	int i = ACE_FIFO_SIZE;
259	while (i--)
260		out_8(r++, *src++);
261	ace->data_ptr = src;
262}
263
264static struct ace_reg_ops ace_reg_8_ops = {
265	.in = ace_in_8,
266	.out = ace_out_8,
267	.datain = ace_datain_8,
268	.dataout = ace_dataout_8,
269};
270
271/* 16 bit big endian bus attachment */
272static u16 ace_in_be16(struct ace_device *ace, int reg)
273{
274	return in_be16(ace->baseaddr + reg);
275}
276
277static void ace_out_be16(struct ace_device *ace, int reg, u16 val)
278{
279	out_be16(ace->baseaddr + reg, val);
280}
281
282static void ace_datain_be16(struct ace_device *ace)
283{
284	int i = ACE_FIFO_SIZE / 2;
285	u16 *dst = ace->data_ptr;
286	while (i--)
287		*dst++ = in_le16(ace->baseaddr + 0x40);
288	ace->data_ptr = dst;
289}
290
291static void ace_dataout_be16(struct ace_device *ace)
292{
293	int i = ACE_FIFO_SIZE / 2;
294	u16 *src = ace->data_ptr;
295	while (i--)
296		out_le16(ace->baseaddr + 0x40, *src++);
297	ace->data_ptr = src;
298}
299
300/* 16 bit little endian bus attachment */
301static u16 ace_in_le16(struct ace_device *ace, int reg)
302{
303	return in_le16(ace->baseaddr + reg);
304}
305
306static void ace_out_le16(struct ace_device *ace, int reg, u16 val)
307{
308	out_le16(ace->baseaddr + reg, val);
309}
310
311static void ace_datain_le16(struct ace_device *ace)
312{
313	int i = ACE_FIFO_SIZE / 2;
314	u16 *dst = ace->data_ptr;
315	while (i--)
316		*dst++ = in_be16(ace->baseaddr + 0x40);
317	ace->data_ptr = dst;
318}
319
320static void ace_dataout_le16(struct ace_device *ace)
321{
322	int i = ACE_FIFO_SIZE / 2;
323	u16 *src = ace->data_ptr;
324	while (i--)
325		out_be16(ace->baseaddr + 0x40, *src++);
326	ace->data_ptr = src;
327}
328
329static struct ace_reg_ops ace_reg_be16_ops = {
330	.in = ace_in_be16,
331	.out = ace_out_be16,
332	.datain = ace_datain_be16,
333	.dataout = ace_dataout_be16,
334};
335
336static struct ace_reg_ops ace_reg_le16_ops = {
337	.in = ace_in_le16,
338	.out = ace_out_le16,
339	.datain = ace_datain_le16,
340	.dataout = ace_dataout_le16,
341};
342
343static inline u16 ace_in(struct ace_device *ace, int reg)
344{
345	return ace->reg_ops->in(ace, reg);
346}
347
348static inline u32 ace_in32(struct ace_device *ace, int reg)
349{
350	return ace_in(ace, reg) | (ace_in(ace, reg + 2) << 16);
351}
352
353static inline void ace_out(struct ace_device *ace, int reg, u16 val)
354{
355	ace->reg_ops->out(ace, reg, val);
356}
357
358static inline void ace_out32(struct ace_device *ace, int reg, u32 val)
359{
360	ace_out(ace, reg, val);
361	ace_out(ace, reg + 2, val >> 16);
362}
363
364/* ---------------------------------------------------------------------
365 * Debug support functions
366 */
367
368#if defined(DEBUG)
369static void ace_dump_mem(void *base, int len)
370{
371	const char *ptr = base;
372	int i, j;
373
374	for (i = 0; i < len; i += 16) {
375		printk(KERN_INFO "%.8x:", i);
376		for (j = 0; j < 16; j++) {
377			if (!(j % 4))
378				printk(" ");
379			printk("%.2x", ptr[i + j]);
380		}
381		printk(" ");
382		for (j = 0; j < 16; j++)
383			printk("%c", isprint(ptr[i + j]) ? ptr[i + j] : '.');
384		printk("\n");
385	}
386}
387#else
388static inline void ace_dump_mem(void *base, int len)
389{
390}
391#endif
392
393static void ace_dump_regs(struct ace_device *ace)
394{
395	dev_info(ace->dev,
396		 "    ctrl:  %.8x  seccnt/cmd: %.4x      ver:%.4x\n"
397		 "    status:%.8x  mpu_lba:%.8x  busmode:%4x\n"
398		 "    error: %.8x  cfg_lba:%.8x  fatstat:%.4x\n",
399		 ace_in32(ace, ACE_CTRL),
400		 ace_in(ace, ACE_SECCNTCMD),
401		 ace_in(ace, ACE_VERSION),
402		 ace_in32(ace, ACE_STATUS),
403		 ace_in32(ace, ACE_MPULBA),
404		 ace_in(ace, ACE_BUSMODE),
405		 ace_in32(ace, ACE_ERROR),
406		 ace_in32(ace, ACE_CFGLBA), ace_in(ace, ACE_FATSTAT));
407}
408
409static void ace_fix_driveid(u16 *id)
410{
411#if defined(__BIG_ENDIAN)
412	int i;
413
414	/* All half words have wrong byte order; swap the bytes */
415	for (i = 0; i < ATA_ID_WORDS; i++, id++)
416		*id = le16_to_cpu(*id);
417#endif
418}
419
420/* ---------------------------------------------------------------------
421 * Finite State Machine (FSM) implementation
422 */
423
424/* FSM tasks; used to direct state transitions */
425#define ACE_TASK_IDLE      0
426#define ACE_TASK_IDENTIFY  1
427#define ACE_TASK_READ      2
428#define ACE_TASK_WRITE     3
429#define ACE_FSM_NUM_TASKS  4
430
431/* FSM state definitions */
432#define ACE_FSM_STATE_IDLE               0
433#define ACE_FSM_STATE_REQ_LOCK           1
434#define ACE_FSM_STATE_WAIT_LOCK          2
435#define ACE_FSM_STATE_WAIT_CFREADY       3
436#define ACE_FSM_STATE_IDENTIFY_PREPARE   4
437#define ACE_FSM_STATE_IDENTIFY_TRANSFER  5
438#define ACE_FSM_STATE_IDENTIFY_COMPLETE  6
439#define ACE_FSM_STATE_REQ_PREPARE        7
440#define ACE_FSM_STATE_REQ_TRANSFER       8
441#define ACE_FSM_STATE_REQ_COMPLETE       9
442#define ACE_FSM_STATE_ERROR             10
443#define ACE_FSM_NUM_STATES              11
444
445/* Set flag to exit FSM loop and reschedule tasklet */
446static inline void ace_fsm_yieldpoll(struct ace_device *ace)
447{
448	tasklet_schedule(&ace->fsm_tasklet);
449	ace->fsm_continue_flag = 0;
450}
451
452static inline void ace_fsm_yield(struct ace_device *ace)
453{
454	dev_dbg(ace->dev, "%s()\n", __func__);
455	ace_fsm_yieldpoll(ace);
456}
457
458/* Set flag to exit FSM loop and wait for IRQ to reschedule tasklet */
459static inline void ace_fsm_yieldirq(struct ace_device *ace)
460{
461	dev_dbg(ace->dev, "ace_fsm_yieldirq()\n");
462
463	if (ace->irq > 0)
464		ace->fsm_continue_flag = 0;
465	else
466		ace_fsm_yieldpoll(ace);
467}
468
469static bool ace_has_next_request(struct request_queue *q)
470{
471	struct ace_device *ace = q->queuedata;
472
473	return !list_empty(&ace->rq_list);
474}
475
476/* Get the next read/write request; ending requests that we don't handle */
477static struct request *ace_get_next_request(struct request_queue *q)
478{
479	struct ace_device *ace = q->queuedata;
480	struct request *rq;
481
482	rq = list_first_entry_or_null(&ace->rq_list, struct request, queuelist);
483	if (rq) {
484		list_del_init(&rq->queuelist);
485		blk_mq_start_request(rq);
486	}
487
488	return NULL;
489}
490
491static void ace_fsm_dostate(struct ace_device *ace)
492{
493	struct request *req;
494	u32 status;
495	u16 val;
496	int count;
497
498#if defined(DEBUG)
499	dev_dbg(ace->dev, "fsm_state=%i, id_req_count=%i\n",
500		ace->fsm_state, ace->id_req_count);
501#endif
502
503	/* Verify that there is actually a CF in the slot. If not, then
504	 * bail out back to the idle state and wake up all the waiters */
505	status = ace_in32(ace, ACE_STATUS);
506	if ((status & ACE_STATUS_CFDETECT) == 0) {
507		ace->fsm_state = ACE_FSM_STATE_IDLE;
508		ace->media_change = 1;
509		set_capacity(ace->gd, 0);
510		dev_info(ace->dev, "No CF in slot\n");
511
512		/* Drop all in-flight and pending requests */
513		if (ace->req) {
514			blk_mq_end_request(ace->req, BLK_STS_IOERR);
515			ace->req = NULL;
516		}
517		while ((req = ace_get_next_request(ace->queue)) != NULL)
518			blk_mq_end_request(req, BLK_STS_IOERR);
519
520		/* Drop back to IDLE state and notify waiters */
521		ace->fsm_state = ACE_FSM_STATE_IDLE;
522		ace->id_result = -EIO;
523		while (ace->id_req_count) {
524			complete(&ace->id_completion);
525			ace->id_req_count--;
526		}
527	}
528
529	switch (ace->fsm_state) {
530	case ACE_FSM_STATE_IDLE:
531		/* See if there is anything to do */
532		if (ace->id_req_count || ace_has_next_request(ace->queue)) {
533			ace->fsm_iter_num++;
534			ace->fsm_state = ACE_FSM_STATE_REQ_LOCK;
535			mod_timer(&ace->stall_timer, jiffies + HZ);
536			if (!timer_pending(&ace->stall_timer))
537				add_timer(&ace->stall_timer);
538			break;
539		}
540		del_timer(&ace->stall_timer);
541		ace->fsm_continue_flag = 0;
542		break;
543
544	case ACE_FSM_STATE_REQ_LOCK:
545		if (ace_in(ace, ACE_STATUS) & ACE_STATUS_MPULOCK) {
546			/* Already have the lock, jump to next state */
547			ace->fsm_state = ACE_FSM_STATE_WAIT_CFREADY;
548			break;
549		}
550
551		/* Request the lock */
552		val = ace_in(ace, ACE_CTRL);
553		ace_out(ace, ACE_CTRL, val | ACE_CTRL_LOCKREQ);
554		ace->fsm_state = ACE_FSM_STATE_WAIT_LOCK;
555		break;
556
557	case ACE_FSM_STATE_WAIT_LOCK:
558		if (ace_in(ace, ACE_STATUS) & ACE_STATUS_MPULOCK) {
559			/* got the lock; move to next state */
560			ace->fsm_state = ACE_FSM_STATE_WAIT_CFREADY;
561			break;
562		}
563
564		/* wait a bit for the lock */
565		ace_fsm_yield(ace);
566		break;
567
568	case ACE_FSM_STATE_WAIT_CFREADY:
569		status = ace_in32(ace, ACE_STATUS);
570		if (!(status & ACE_STATUS_RDYFORCFCMD) ||
571		    (status & ACE_STATUS_CFBSY)) {
572			/* CF card isn't ready; it needs to be polled */
573			ace_fsm_yield(ace);
574			break;
575		}
576
577		/* Device is ready for command; determine what to do next */
578		if (ace->id_req_count)
579			ace->fsm_state = ACE_FSM_STATE_IDENTIFY_PREPARE;
580		else
581			ace->fsm_state = ACE_FSM_STATE_REQ_PREPARE;
582		break;
583
584	case ACE_FSM_STATE_IDENTIFY_PREPARE:
585		/* Send identify command */
586		ace->fsm_task = ACE_TASK_IDENTIFY;
587		ace->data_ptr = ace->cf_id;
588		ace->data_count = ACE_BUF_PER_SECTOR;
589		ace_out(ace, ACE_SECCNTCMD, ACE_SECCNTCMD_IDENTIFY);
590
591		/* As per datasheet, put config controller in reset */
592		val = ace_in(ace, ACE_CTRL);
593		ace_out(ace, ACE_CTRL, val | ACE_CTRL_CFGRESET);
594
595		/* irq handler takes over from this point; wait for the
596		 * transfer to complete */
597		ace->fsm_state = ACE_FSM_STATE_IDENTIFY_TRANSFER;
598		ace_fsm_yieldirq(ace);
599		break;
600
601	case ACE_FSM_STATE_IDENTIFY_TRANSFER:
602		/* Check that the sysace is ready to receive data */
603		status = ace_in32(ace, ACE_STATUS);
604		if (status & ACE_STATUS_CFBSY) {
605			dev_dbg(ace->dev, "CFBSY set; t=%i iter=%i dc=%i\n",
606				ace->fsm_task, ace->fsm_iter_num,
607				ace->data_count);
608			ace_fsm_yield(ace);
609			break;
610		}
611		if (!(status & ACE_STATUS_DATABUFRDY)) {
612			ace_fsm_yield(ace);
613			break;
614		}
615
616		/* Transfer the next buffer */
617		ace->reg_ops->datain(ace);
618		ace->data_count--;
619
620		/* If there are still buffers to be transfers; jump out here */
621		if (ace->data_count != 0) {
622			ace_fsm_yieldirq(ace);
623			break;
624		}
625
626		/* transfer finished; kick state machine */
627		dev_dbg(ace->dev, "identify finished\n");
628		ace->fsm_state = ACE_FSM_STATE_IDENTIFY_COMPLETE;
629		break;
630
631	case ACE_FSM_STATE_IDENTIFY_COMPLETE:
632		ace_fix_driveid(ace->cf_id);
633		ace_dump_mem(ace->cf_id, 512);	/* Debug: Dump out disk ID */
634
635		if (ace->data_result) {
636			/* Error occurred, disable the disk */
637			ace->media_change = 1;
638			set_capacity(ace->gd, 0);
639			dev_err(ace->dev, "error fetching CF id (%i)\n",
640				ace->data_result);
641		} else {
642			ace->media_change = 0;
643
644			/* Record disk parameters */
645			set_capacity(ace->gd,
646				ata_id_u32(ace->cf_id, ATA_ID_LBA_CAPACITY));
647			dev_info(ace->dev, "capacity: %i sectors\n",
648				ata_id_u32(ace->cf_id, ATA_ID_LBA_CAPACITY));
649		}
650
651		/* We're done, drop to IDLE state and notify waiters */
652		ace->fsm_state = ACE_FSM_STATE_IDLE;
653		ace->id_result = ace->data_result;
654		while (ace->id_req_count) {
655			complete(&ace->id_completion);
656			ace->id_req_count--;
657		}
658		break;
659
660	case ACE_FSM_STATE_REQ_PREPARE:
661		req = ace_get_next_request(ace->queue);
662		if (!req) {
663			ace->fsm_state = ACE_FSM_STATE_IDLE;
664			break;
665		}
666
667		/* Okay, it's a data request, set it up for transfer */
668		dev_dbg(ace->dev,
669			"request: sec=%llx hcnt=%x, ccnt=%x, dir=%i\n",
670			(unsigned long long)blk_rq_pos(req),
671			blk_rq_sectors(req), blk_rq_cur_sectors(req),
672			rq_data_dir(req));
673
674		ace->req = req;
675		ace->data_ptr = bio_data(req->bio);
676		ace->data_count = blk_rq_cur_sectors(req) * ACE_BUF_PER_SECTOR;
677		ace_out32(ace, ACE_MPULBA, blk_rq_pos(req) & 0x0FFFFFFF);
678
679		count = blk_rq_sectors(req);
680		if (rq_data_dir(req)) {
681			/* Kick off write request */
682			dev_dbg(ace->dev, "write data\n");
683			ace->fsm_task = ACE_TASK_WRITE;
684			ace_out(ace, ACE_SECCNTCMD,
685				count | ACE_SECCNTCMD_WRITE_DATA);
686		} else {
687			/* Kick off read request */
688			dev_dbg(ace->dev, "read data\n");
689			ace->fsm_task = ACE_TASK_READ;
690			ace_out(ace, ACE_SECCNTCMD,
691				count | ACE_SECCNTCMD_READ_DATA);
692		}
693
694		/* As per datasheet, put config controller in reset */
695		val = ace_in(ace, ACE_CTRL);
696		ace_out(ace, ACE_CTRL, val | ACE_CTRL_CFGRESET);
697
698		/* Move to the transfer state.  The systemace will raise
699		 * an interrupt once there is something to do
700		 */
701		ace->fsm_state = ACE_FSM_STATE_REQ_TRANSFER;
702		if (ace->fsm_task == ACE_TASK_READ)
703			ace_fsm_yieldirq(ace);	/* wait for data ready */
704		break;
705
706	case ACE_FSM_STATE_REQ_TRANSFER:
707		/* Check that the sysace is ready to receive data */
708		status = ace_in32(ace, ACE_STATUS);
709		if (status & ACE_STATUS_CFBSY) {
710			dev_dbg(ace->dev,
711				"CFBSY set; t=%i iter=%i c=%i dc=%i irq=%i\n",
712				ace->fsm_task, ace->fsm_iter_num,
713				blk_rq_cur_sectors(ace->req) * 16,
714				ace->data_count, ace->in_irq);
715			ace_fsm_yield(ace);	/* need to poll CFBSY bit */
716			break;
717		}
718		if (!(status & ACE_STATUS_DATABUFRDY)) {
719			dev_dbg(ace->dev,
720				"DATABUF not set; t=%i iter=%i c=%i dc=%i irq=%i\n",
721				ace->fsm_task, ace->fsm_iter_num,
722				blk_rq_cur_sectors(ace->req) * 16,
723				ace->data_count, ace->in_irq);
724			ace_fsm_yieldirq(ace);
725			break;
726		}
727
728		/* Transfer the next buffer */
729		if (ace->fsm_task == ACE_TASK_WRITE)
730			ace->reg_ops->dataout(ace);
731		else
732			ace->reg_ops->datain(ace);
733		ace->data_count--;
734
735		/* If there are still buffers to be transfers; jump out here */
736		if (ace->data_count != 0) {
737			ace_fsm_yieldirq(ace);
738			break;
739		}
740
741		/* bio finished; is there another one? */
742		if (blk_update_request(ace->req, BLK_STS_OK,
743		    blk_rq_cur_bytes(ace->req))) {
744			/* dev_dbg(ace->dev, "next block; h=%u c=%u\n",
745			 *      blk_rq_sectors(ace->req),
746			 *      blk_rq_cur_sectors(ace->req));
747			 */
748			ace->data_ptr = bio_data(ace->req->bio);
749			ace->data_count = blk_rq_cur_sectors(ace->req) * 16;
750			ace_fsm_yieldirq(ace);
751			break;
752		}
753
754		ace->fsm_state = ACE_FSM_STATE_REQ_COMPLETE;
755		break;
756
757	case ACE_FSM_STATE_REQ_COMPLETE:
758		ace->req = NULL;
759
760		/* Finished request; go to idle state */
761		ace->fsm_state = ACE_FSM_STATE_IDLE;
762		break;
763
764	default:
765		ace->fsm_state = ACE_FSM_STATE_IDLE;
766		break;
767	}
768}
769
770static void ace_fsm_tasklet(unsigned long data)
771{
772	struct ace_device *ace = (void *)data;
773	unsigned long flags;
774
775	spin_lock_irqsave(&ace->lock, flags);
776
777	/* Loop over state machine until told to stop */
778	ace->fsm_continue_flag = 1;
779	while (ace->fsm_continue_flag)
780		ace_fsm_dostate(ace);
781
782	spin_unlock_irqrestore(&ace->lock, flags);
783}
784
785static void ace_stall_timer(struct timer_list *t)
786{
787	struct ace_device *ace = from_timer(ace, t, stall_timer);
788	unsigned long flags;
789
790	dev_warn(ace->dev,
791		 "kicking stalled fsm; state=%i task=%i iter=%i dc=%i\n",
792		 ace->fsm_state, ace->fsm_task, ace->fsm_iter_num,
793		 ace->data_count);
794	spin_lock_irqsave(&ace->lock, flags);
795
796	/* Rearm the stall timer *before* entering FSM (which may then
797	 * delete the timer) */
798	mod_timer(&ace->stall_timer, jiffies + HZ);
799
800	/* Loop over state machine until told to stop */
801	ace->fsm_continue_flag = 1;
802	while (ace->fsm_continue_flag)
803		ace_fsm_dostate(ace);
804
805	spin_unlock_irqrestore(&ace->lock, flags);
806}
807
808/* ---------------------------------------------------------------------
809 * Interrupt handling routines
810 */
811static int ace_interrupt_checkstate(struct ace_device *ace)
812{
813	u32 sreg = ace_in32(ace, ACE_STATUS);
814	u16 creg = ace_in(ace, ACE_CTRL);
815
816	/* Check for error occurrence */
817	if ((sreg & (ACE_STATUS_CFGERROR | ACE_STATUS_CFCERROR)) &&
818	    (creg & ACE_CTRL_ERRORIRQ)) {
819		dev_err(ace->dev, "transfer failure\n");
820		ace_dump_regs(ace);
821		return -EIO;
822	}
823
824	return 0;
825}
826
827static irqreturn_t ace_interrupt(int irq, void *dev_id)
828{
829	u16 creg;
830	struct ace_device *ace = dev_id;
831
832	/* be safe and get the lock */
833	spin_lock(&ace->lock);
834	ace->in_irq = 1;
835
836	/* clear the interrupt */
837	creg = ace_in(ace, ACE_CTRL);
838	ace_out(ace, ACE_CTRL, creg | ACE_CTRL_RESETIRQ);
839	ace_out(ace, ACE_CTRL, creg);
840
841	/* check for IO failures */
842	if (ace_interrupt_checkstate(ace))
843		ace->data_result = -EIO;
844
845	if (ace->fsm_task == 0) {
846		dev_err(ace->dev,
847			"spurious irq; stat=%.8x ctrl=%.8x cmd=%.4x\n",
848			ace_in32(ace, ACE_STATUS), ace_in32(ace, ACE_CTRL),
849			ace_in(ace, ACE_SECCNTCMD));
850		dev_err(ace->dev, "fsm_task=%i fsm_state=%i data_count=%i\n",
851			ace->fsm_task, ace->fsm_state, ace->data_count);
852	}
853
854	/* Loop over state machine until told to stop */
855	ace->fsm_continue_flag = 1;
856	while (ace->fsm_continue_flag)
857		ace_fsm_dostate(ace);
858
859	/* done with interrupt; drop the lock */
860	ace->in_irq = 0;
861	spin_unlock(&ace->lock);
862
863	return IRQ_HANDLED;
864}
865
866/* ---------------------------------------------------------------------
867 * Block ops
868 */
869static blk_status_t ace_queue_rq(struct blk_mq_hw_ctx *hctx,
870				 const struct blk_mq_queue_data *bd)
871{
872	struct ace_device *ace = hctx->queue->queuedata;
873	struct request *req = bd->rq;
874
875	if (blk_rq_is_passthrough(req)) {
876		blk_mq_start_request(req);
877		return BLK_STS_IOERR;
878	}
879
880	spin_lock_irq(&ace->lock);
881	list_add_tail(&req->queuelist, &ace->rq_list);
882	spin_unlock_irq(&ace->lock);
883
884	tasklet_schedule(&ace->fsm_tasklet);
885	return BLK_STS_OK;
886}
887
888static unsigned int ace_check_events(struct gendisk *gd, unsigned int clearing)
889{
890	struct ace_device *ace = gd->private_data;
891	dev_dbg(ace->dev, "ace_check_events(): %i\n", ace->media_change);
892
893	return ace->media_change ? DISK_EVENT_MEDIA_CHANGE : 0;
894}
895
896static void ace_media_changed(struct ace_device *ace)
897{
898	unsigned long flags;
899
900	dev_dbg(ace->dev, "requesting cf id and scheduling tasklet\n");
901
902	spin_lock_irqsave(&ace->lock, flags);
903	ace->id_req_count++;
904	spin_unlock_irqrestore(&ace->lock, flags);
905
906	tasklet_schedule(&ace->fsm_tasklet);
907	wait_for_completion(&ace->id_completion);
908
909	dev_dbg(ace->dev, "revalidate complete\n");
910}
911
912static int ace_open(struct block_device *bdev, fmode_t mode)
913{
914	struct ace_device *ace = bdev->bd_disk->private_data;
915	unsigned long flags;
916
917	dev_dbg(ace->dev, "ace_open() users=%i\n", ace->users + 1);
918
919	mutex_lock(&xsysace_mutex);
920	spin_lock_irqsave(&ace->lock, flags);
921	ace->users++;
922	spin_unlock_irqrestore(&ace->lock, flags);
923
924	if (bdev_check_media_change(bdev) && ace->media_change)
925		ace_media_changed(ace);
926	mutex_unlock(&xsysace_mutex);
927
928	return 0;
929}
930
931static void ace_release(struct gendisk *disk, fmode_t mode)
932{
933	struct ace_device *ace = disk->private_data;
934	unsigned long flags;
935	u16 val;
936
937	dev_dbg(ace->dev, "ace_release() users=%i\n", ace->users - 1);
938
939	mutex_lock(&xsysace_mutex);
940	spin_lock_irqsave(&ace->lock, flags);
941	ace->users--;
942	if (ace->users == 0) {
943		val = ace_in(ace, ACE_CTRL);
944		ace_out(ace, ACE_CTRL, val & ~ACE_CTRL_LOCKREQ);
945	}
946	spin_unlock_irqrestore(&ace->lock, flags);
947	mutex_unlock(&xsysace_mutex);
948}
949
950static int ace_getgeo(struct block_device *bdev, struct hd_geometry *geo)
951{
952	struct ace_device *ace = bdev->bd_disk->private_data;
953	u16 *cf_id = ace->cf_id;
954
955	dev_dbg(ace->dev, "ace_getgeo()\n");
956
957	geo->heads	= cf_id[ATA_ID_HEADS];
958	geo->sectors	= cf_id[ATA_ID_SECTORS];
959	geo->cylinders	= cf_id[ATA_ID_CYLS];
960
961	return 0;
962}
963
964static const struct block_device_operations ace_fops = {
965	.owner = THIS_MODULE,
966	.open = ace_open,
967	.release = ace_release,
968	.check_events = ace_check_events,
969	.getgeo = ace_getgeo,
970};
971
972static const struct blk_mq_ops ace_mq_ops = {
973	.queue_rq	= ace_queue_rq,
974};
975
976/* --------------------------------------------------------------------
977 * SystemACE device setup/teardown code
978 */
979static int ace_setup(struct ace_device *ace)
980{
981	u16 version;
982	u16 val;
983	int rc;
984
985	dev_dbg(ace->dev, "ace_setup(ace=0x%p)\n", ace);
986	dev_dbg(ace->dev, "physaddr=0x%llx irq=%i\n",
987		(unsigned long long)ace->physaddr, ace->irq);
988
989	spin_lock_init(&ace->lock);
990	init_completion(&ace->id_completion);
991	INIT_LIST_HEAD(&ace->rq_list);
992
993	/*
994	 * Map the device
995	 */
996	ace->baseaddr = ioremap(ace->physaddr, 0x80);
997	if (!ace->baseaddr)
998		goto err_ioremap;
999
1000	/*
1001	 * Initialize the state machine tasklet and stall timer
1002	 */
1003	tasklet_init(&ace->fsm_tasklet, ace_fsm_tasklet, (unsigned long)ace);
1004	timer_setup(&ace->stall_timer, ace_stall_timer, 0);
1005
1006	/*
1007	 * Initialize the request queue
1008	 */
1009	ace->queue = blk_mq_init_sq_queue(&ace->tag_set, &ace_mq_ops, 2,
1010						BLK_MQ_F_SHOULD_MERGE);
1011	if (IS_ERR(ace->queue)) {
1012		rc = PTR_ERR(ace->queue);
1013		ace->queue = NULL;
1014		goto err_blk_initq;
1015	}
1016	ace->queue->queuedata = ace;
1017
1018	blk_queue_logical_block_size(ace->queue, 512);
1019	blk_queue_bounce_limit(ace->queue, BLK_BOUNCE_HIGH);
1020
1021	/*
1022	 * Allocate and initialize GD structure
1023	 */
1024	ace->gd = alloc_disk(ACE_NUM_MINORS);
1025	if (!ace->gd)
1026		goto err_alloc_disk;
1027
1028	ace->gd->major = ace_major;
1029	ace->gd->first_minor = ace->id * ACE_NUM_MINORS;
1030	ace->gd->fops = &ace_fops;
1031	ace->gd->events = DISK_EVENT_MEDIA_CHANGE;
1032	ace->gd->queue = ace->queue;
1033	ace->gd->private_data = ace;
1034	snprintf(ace->gd->disk_name, 32, "xs%c", ace->id + 'a');
1035
1036	/* set bus width */
1037	if (ace->bus_width == ACE_BUS_WIDTH_16) {
1038		/* 0x0101 should work regardless of endianess */
1039		ace_out_le16(ace, ACE_BUSMODE, 0x0101);
1040
1041		/* read it back to determine endianess */
1042		if (ace_in_le16(ace, ACE_BUSMODE) == 0x0001)
1043			ace->reg_ops = &ace_reg_le16_ops;
1044		else
1045			ace->reg_ops = &ace_reg_be16_ops;
1046	} else {
1047		ace_out_8(ace, ACE_BUSMODE, 0x00);
1048		ace->reg_ops = &ace_reg_8_ops;
1049	}
1050
1051	/* Make sure version register is sane */
1052	version = ace_in(ace, ACE_VERSION);
1053	if ((version == 0) || (version == 0xFFFF))
1054		goto err_read;
1055
1056	/* Put sysace in a sane state by clearing most control reg bits */
1057	ace_out(ace, ACE_CTRL, ACE_CTRL_FORCECFGMODE |
1058		ACE_CTRL_DATABUFRDYIRQ | ACE_CTRL_ERRORIRQ);
1059
1060	/* Now we can hook up the irq handler */
1061	if (ace->irq > 0) {
1062		rc = request_irq(ace->irq, ace_interrupt, 0, "systemace", ace);
1063		if (rc) {
1064			/* Failure - fall back to polled mode */
1065			dev_err(ace->dev, "request_irq failed\n");
1066			ace->irq = rc;
1067		}
1068	}
1069
1070	/* Enable interrupts */
1071	val = ace_in(ace, ACE_CTRL);
1072	val |= ACE_CTRL_DATABUFRDYIRQ | ACE_CTRL_ERRORIRQ;
1073	ace_out(ace, ACE_CTRL, val);
1074
1075	/* Print the identification */
1076	dev_info(ace->dev, "Xilinx SystemACE revision %i.%i.%i\n",
1077		 (version >> 12) & 0xf, (version >> 8) & 0x0f, version & 0xff);
1078	dev_dbg(ace->dev, "physaddr 0x%llx, mapped to 0x%p, irq=%i\n",
1079		(unsigned long long) ace->physaddr, ace->baseaddr, ace->irq);
1080
1081	ace->media_change = 1;
1082	ace_media_changed(ace);
1083
1084	/* Make the sysace device 'live' */
1085	add_disk(ace->gd);
1086
1087	return 0;
1088
1089err_read:
1090	/* prevent double queue cleanup */
1091	ace->gd->queue = NULL;
1092	put_disk(ace->gd);
1093err_alloc_disk:
1094	blk_cleanup_queue(ace->queue);
1095	blk_mq_free_tag_set(&ace->tag_set);
1096err_blk_initq:
1097	iounmap(ace->baseaddr);
1098err_ioremap:
1099	dev_info(ace->dev, "xsysace: error initializing device at 0x%llx\n",
1100		 (unsigned long long) ace->physaddr);
1101	return -ENOMEM;
1102}
1103
1104static void ace_teardown(struct ace_device *ace)
1105{
1106	if (ace->gd) {
1107		del_gendisk(ace->gd);
1108		put_disk(ace->gd);
1109	}
1110
1111	if (ace->queue) {
1112		blk_cleanup_queue(ace->queue);
1113		blk_mq_free_tag_set(&ace->tag_set);
1114	}
1115
1116	tasklet_kill(&ace->fsm_tasklet);
1117
1118	if (ace->irq > 0)
1119		free_irq(ace->irq, ace);
1120
1121	iounmap(ace->baseaddr);
1122}
1123
1124static int ace_alloc(struct device *dev, int id, resource_size_t physaddr,
1125		     int irq, int bus_width)
1126{
1127	struct ace_device *ace;
1128	int rc;
1129	dev_dbg(dev, "ace_alloc(%p)\n", dev);
1130
1131	/* Allocate and initialize the ace device structure */
1132	ace = kzalloc(sizeof(struct ace_device), GFP_KERNEL);
1133	if (!ace) {
1134		rc = -ENOMEM;
1135		goto err_alloc;
1136	}
1137
1138	ace->dev = dev;
1139	ace->id = id;
1140	ace->physaddr = physaddr;
1141	ace->irq = irq;
1142	ace->bus_width = bus_width;
1143
1144	/* Call the setup code */
1145	rc = ace_setup(ace);
1146	if (rc)
1147		goto err_setup;
1148
1149	dev_set_drvdata(dev, ace);
1150	return 0;
1151
1152err_setup:
1153	dev_set_drvdata(dev, NULL);
1154	kfree(ace);
1155err_alloc:
1156	dev_err(dev, "could not initialize device, err=%i\n", rc);
1157	return rc;
1158}
1159
1160static void ace_free(struct device *dev)
1161{
1162	struct ace_device *ace = dev_get_drvdata(dev);
1163	dev_dbg(dev, "ace_free(%p)\n", dev);
1164
1165	if (ace) {
1166		ace_teardown(ace);
1167		dev_set_drvdata(dev, NULL);
1168		kfree(ace);
1169	}
1170}
1171
1172/* ---------------------------------------------------------------------
1173 * Platform Bus Support
1174 */
1175
1176static int ace_probe(struct platform_device *dev)
1177{
1178	int bus_width = ACE_BUS_WIDTH_16; /* FIXME: should not be hard coded */
1179	resource_size_t physaddr;
1180	struct resource *res;
1181	u32 id = dev->id;
1182	int irq;
1183	int i;
1184
1185	dev_dbg(&dev->dev, "ace_probe(%p)\n", dev);
1186
1187	/* device id and bus width */
1188	if (of_property_read_u32(dev->dev.of_node, "port-number", &id))
1189		id = 0;
1190	if (of_find_property(dev->dev.of_node, "8-bit", NULL))
1191		bus_width = ACE_BUS_WIDTH_8;
1192
1193	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
1194	if (!res)
1195		return -EINVAL;
1196
1197	physaddr = res->start;
1198	if (!physaddr)
1199		return -ENODEV;
1200
1201	irq = platform_get_irq_optional(dev, 0);
1202
1203	/* Call the bus-independent setup code */
1204	return ace_alloc(&dev->dev, id, physaddr, irq, bus_width);
1205}
1206
1207/*
1208 * Platform bus remove() method
1209 */
1210static int ace_remove(struct platform_device *dev)
1211{
1212	ace_free(&dev->dev);
1213	return 0;
1214}
1215
1216#if defined(CONFIG_OF)
1217/* Match table for of_platform binding */
1218static const struct of_device_id ace_of_match[] = {
1219	{ .compatible = "xlnx,opb-sysace-1.00.b", },
1220	{ .compatible = "xlnx,opb-sysace-1.00.c", },
1221	{ .compatible = "xlnx,xps-sysace-1.00.a", },
1222	{ .compatible = "xlnx,sysace", },
1223	{},
1224};
1225MODULE_DEVICE_TABLE(of, ace_of_match);
1226#else /* CONFIG_OF */
1227#define ace_of_match NULL
1228#endif /* CONFIG_OF */
1229
1230static struct platform_driver ace_platform_driver = {
1231	.probe = ace_probe,
1232	.remove = ace_remove,
1233	.driver = {
1234		.name = "xsysace",
1235		.of_match_table = ace_of_match,
1236	},
1237};
1238
1239/* ---------------------------------------------------------------------
1240 * Module init/exit routines
1241 */
1242static int __init ace_init(void)
1243{
1244	int rc;
1245
1246	ace_major = register_blkdev(ace_major, "xsysace");
1247	if (ace_major <= 0) {
1248		rc = -ENOMEM;
1249		goto err_blk;
1250	}
1251
1252	rc = platform_driver_register(&ace_platform_driver);
1253	if (rc)
1254		goto err_plat;
1255
1256	pr_info("Xilinx SystemACE device driver, major=%i\n", ace_major);
1257	return 0;
1258
1259err_plat:
1260	unregister_blkdev(ace_major, "xsysace");
1261err_blk:
1262	printk(KERN_ERR "xsysace: registration failed; err=%i\n", rc);
1263	return rc;
1264}
1265module_init(ace_init);
1266
1267static void __exit ace_exit(void)
1268{
1269	pr_debug("Unregistering Xilinx SystemACE driver\n");
1270	platform_driver_unregister(&ace_platform_driver);
1271	unregister_blkdev(ace_major, "xsysace");
1272}
1273module_exit(ace_exit);
1274