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