Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[linux-2.6] / drivers / spi / spi_bfin5xx.c
1 /*
2  * File:         drivers/spi/bfin5xx_spi.c
3  * Based on:     N/A
4  * Author:       Luke Yang (Analog Devices Inc.)
5  *
6  * Created:      March. 10th 2006
7  * Description:  SPI controller driver for Blackfin 5xx
8  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
9  *
10  * Modified:
11  *      March 10, 2006  bfin5xx_spi.c Created. (Luke Yang)
12  *      August 7, 2006  added full duplex mode (Axel Weiss & Luke Yang)
13  *
14  * Copyright 2004-2006 Analog Devices Inc.
15  *
16  * This program is free software ;  you can redistribute it and/or modify
17  * it under the terms of the GNU General Public License as published by
18  * the Free Software Foundation ;  either version 2, or (at your option)
19  * any later version.
20  *
21  * This program is distributed in the hope that it will be useful,
22  * but WITHOUT ANY WARRANTY ;  without even the implied warranty of
23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24  * GNU General Public License for more details.
25  *
26  * You should have received a copy of the GNU General Public License
27  * along with this program ;  see the file COPYING.
28  * If not, write to the Free Software Foundation,
29  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
30  */
31
32 #include <linux/init.h>
33 #include <linux/module.h>
34 #include <linux/device.h>
35 #include <linux/ioport.h>
36 #include <linux/errno.h>
37 #include <linux/interrupt.h>
38 #include <linux/platform_device.h>
39 #include <linux/dma-mapping.h>
40 #include <linux/spi/spi.h>
41 #include <linux/workqueue.h>
42 #include <linux/errno.h>
43 #include <linux/delay.h>
44
45 #include <asm/io.h>
46 #include <asm/irq.h>
47 #include <asm/delay.h>
48 #include <asm/dma.h>
49
50 #include <asm/bfin5xx_spi.h>
51
52 MODULE_AUTHOR("Luke Yang");
53 MODULE_DESCRIPTION("Blackfin 5xx SPI Contoller");
54 MODULE_LICENSE("GPL");
55
56 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
57
58 #define DEFINE_SPI_REG(reg, off) \
59 static inline u16 read_##reg(void) \
60             { return *(volatile unsigned short*)(SPI0_REGBASE + off); } \
61 static inline void write_##reg(u16 v) \
62             {*(volatile unsigned short*)(SPI0_REGBASE + off) = v;\
63              SSYNC();}
64
65 DEFINE_SPI_REG(CTRL, 0x00)
66 DEFINE_SPI_REG(FLAG, 0x04)
67 DEFINE_SPI_REG(STAT, 0x08)
68 DEFINE_SPI_REG(TDBR, 0x0C)
69 DEFINE_SPI_REG(RDBR, 0x10)
70 DEFINE_SPI_REG(BAUD, 0x14)
71 DEFINE_SPI_REG(SHAW, 0x18)
72 #define START_STATE ((void*)0)
73 #define RUNNING_STATE ((void*)1)
74 #define DONE_STATE ((void*)2)
75 #define ERROR_STATE ((void*)-1)
76 #define QUEUE_RUNNING 0
77 #define QUEUE_STOPPED 1
78 int dma_requested;
79
80 struct driver_data {
81         /* Driver model hookup */
82         struct platform_device *pdev;
83
84         /* SPI framework hookup */
85         struct spi_master *master;
86
87         /* BFIN hookup */
88         struct bfin5xx_spi_master *master_info;
89
90         /* Driver message queue */
91         struct workqueue_struct *workqueue;
92         struct work_struct pump_messages;
93         spinlock_t lock;
94         struct list_head queue;
95         int busy;
96         int run;
97
98         /* Message Transfer pump */
99         struct tasklet_struct pump_transfers;
100
101         /* Current message transfer state info */
102         struct spi_message *cur_msg;
103         struct spi_transfer *cur_transfer;
104         struct chip_data *cur_chip;
105         size_t len_in_bytes;
106         size_t len;
107         void *tx;
108         void *tx_end;
109         void *rx;
110         void *rx_end;
111         int dma_mapped;
112         dma_addr_t rx_dma;
113         dma_addr_t tx_dma;
114         size_t rx_map_len;
115         size_t tx_map_len;
116         u8 n_bytes;
117         void (*write) (struct driver_data *);
118         void (*read) (struct driver_data *);
119         void (*duplex) (struct driver_data *);
120 };
121
122 struct chip_data {
123         u16 ctl_reg;
124         u16 baud;
125         u16 flag;
126
127         u8 chip_select_num;
128         u8 n_bytes;
129         u32 width;              /* 0 or 1 */
130         u8 enable_dma;
131         u8 bits_per_word;       /* 8 or 16 */
132         u8 cs_change_per_word;
133         u8 cs_chg_udelay;
134         void (*write) (struct driver_data *);
135         void (*read) (struct driver_data *);
136         void (*duplex) (struct driver_data *);
137 };
138
139 void bfin_spi_enable(struct driver_data *drv_data)
140 {
141         u16 cr;
142
143         cr = read_CTRL();
144         write_CTRL(cr | BIT_CTL_ENABLE);
145         SSYNC();
146 }
147
148 void bfin_spi_disable(struct driver_data *drv_data)
149 {
150         u16 cr;
151
152         cr = read_CTRL();
153         write_CTRL(cr & (~BIT_CTL_ENABLE));
154         SSYNC();
155 }
156
157 /* Caculate the SPI_BAUD register value based on input HZ */
158 static u16 hz_to_spi_baud(u32 speed_hz)
159 {
160         u_long sclk = get_sclk();
161         u16 spi_baud = (sclk / (2 * speed_hz));
162
163         if ((sclk % (2 * speed_hz)) > 0)
164                 spi_baud++;
165
166         pr_debug("sclk = %ld, speed_hz = %d, spi_baud = %d\n", sclk, speed_hz,
167                  spi_baud);
168
169         return spi_baud;
170 }
171
172 static int flush(struct driver_data *drv_data)
173 {
174         unsigned long limit = loops_per_jiffy << 1;
175
176         /* wait for stop and clear stat */
177         while (!(read_STAT() & BIT_STAT_SPIF) && limit--)
178                 continue;
179
180         write_STAT(BIT_STAT_CLR);
181
182         return limit;
183 }
184
185 /* stop controller and re-config current chip*/
186 static void restore_state(struct driver_data *drv_data)
187 {
188         struct chip_data *chip = drv_data->cur_chip;
189
190         /* Clear status and disable clock */
191         write_STAT(BIT_STAT_CLR);
192         bfin_spi_disable(drv_data);
193         pr_debug("restoring spi ctl state\n");
194
195 #if defined(CONFIG_BF534) || defined(CONFIG_BF536) || defined(CONFIG_BF537)
196         pr_debug("chip select number is %d\n", chip->chip_select_num);
197
198         switch (chip->chip_select_num) {
199         case 1:
200                 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3c00);
201                 SSYNC();
202                 break;
203
204         case 2:
205         case 3:
206                 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJSE_SPI);
207                 SSYNC();
208                 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
209                 SSYNC();
210                 break;
211
212         case 4:
213                 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS4E_SPI);
214                 SSYNC();
215                 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3840);
216                 SSYNC();
217                 break;
218
219         case 5:
220                 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS5E_SPI);
221                 SSYNC();
222                 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3820);
223                 SSYNC();
224                 break;
225
226         case 6:
227                 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS6E_SPI);
228                 SSYNC();
229                 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3810);
230                 SSYNC();
231                 break;
232
233         case 7:
234                 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJCE_SPI);
235                 SSYNC();
236                 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
237                 SSYNC();
238                 break;
239         }
240 #endif
241
242         /* Load the registers */
243         write_CTRL(chip->ctl_reg);
244         write_BAUD(chip->baud);
245         write_FLAG(chip->flag);
246 }
247
248 /* used to kick off transfer in rx mode */
249 static unsigned short dummy_read(void)
250 {
251         unsigned short tmp;
252         tmp = read_RDBR();
253         return tmp;
254 }
255
256 static void null_writer(struct driver_data *drv_data)
257 {
258         u8 n_bytes = drv_data->n_bytes;
259
260         while (drv_data->tx < drv_data->tx_end) {
261                 write_TDBR(0);
262                 while ((read_STAT() & BIT_STAT_TXS))
263                         continue;
264                 drv_data->tx += n_bytes;
265         }
266 }
267
268 static void null_reader(struct driver_data *drv_data)
269 {
270         u8 n_bytes = drv_data->n_bytes;
271         dummy_read();
272
273         while (drv_data->rx < drv_data->rx_end) {
274                 while (!(read_STAT() & BIT_STAT_RXS))
275                         continue;
276                 dummy_read();
277                 drv_data->rx += n_bytes;
278         }
279 }
280
281 static void u8_writer(struct driver_data *drv_data)
282 {
283         pr_debug("cr8-s is 0x%x\n", read_STAT());
284         while (drv_data->tx < drv_data->tx_end) {
285                 write_TDBR(*(u8 *) (drv_data->tx));
286                 while (read_STAT() & BIT_STAT_TXS)
287                         continue;
288                 ++drv_data->tx;
289         }
290
291         /* poll for SPI completion before returning */
292         while (!(read_STAT() & BIT_STAT_SPIF))
293                 continue;
294 }
295
296 static void u8_cs_chg_writer(struct driver_data *drv_data)
297 {
298         struct chip_data *chip = drv_data->cur_chip;
299
300         while (drv_data->tx < drv_data->tx_end) {
301                 write_FLAG(chip->flag);
302                 SSYNC();
303
304                 write_TDBR(*(u8 *) (drv_data->tx));
305                 while (read_STAT() & BIT_STAT_TXS)
306                         continue;
307                 while (!(read_STAT() & BIT_STAT_SPIF))
308                         continue;
309                 write_FLAG(0xFF00 | chip->flag);
310                 SSYNC();
311                 if (chip->cs_chg_udelay)
312                         udelay(chip->cs_chg_udelay);
313                 ++drv_data->tx;
314         }
315         write_FLAG(0xFF00);
316         SSYNC();
317 }
318
319 static void u8_reader(struct driver_data *drv_data)
320 {
321         pr_debug("cr-8 is 0x%x\n", read_STAT());
322
323         /* clear TDBR buffer before read(else it will be shifted out) */
324         write_TDBR(0xFFFF);
325
326         dummy_read();
327
328         while (drv_data->rx < drv_data->rx_end - 1) {
329                 while (!(read_STAT() & BIT_STAT_RXS))
330                         continue;
331                 *(u8 *) (drv_data->rx) = read_RDBR();
332                 ++drv_data->rx;
333         }
334
335         while (!(read_STAT() & BIT_STAT_RXS))
336                 continue;
337         *(u8 *) (drv_data->rx) = read_SHAW();
338         ++drv_data->rx;
339 }
340
341 static void u8_cs_chg_reader(struct driver_data *drv_data)
342 {
343         struct chip_data *chip = drv_data->cur_chip;
344
345         while (drv_data->rx < drv_data->rx_end) {
346                 write_FLAG(chip->flag);
347                 SSYNC();
348
349                 read_RDBR();    /* kick off */
350                 while (!(read_STAT() & BIT_STAT_RXS))
351                         continue;
352                 while (!(read_STAT() & BIT_STAT_SPIF))
353                         continue;
354                 *(u8 *) (drv_data->rx) = read_SHAW();
355                 write_FLAG(0xFF00 | chip->flag);
356                 SSYNC();
357                 if (chip->cs_chg_udelay)
358                         udelay(chip->cs_chg_udelay);
359                 ++drv_data->rx;
360         }
361         write_FLAG(0xFF00);
362         SSYNC();
363 }
364
365 static void u8_duplex(struct driver_data *drv_data)
366 {
367         /* in duplex mode, clk is triggered by writing of TDBR */
368         while (drv_data->rx < drv_data->rx_end) {
369                 write_TDBR(*(u8 *) (drv_data->tx));
370                 while (!(read_STAT() & BIT_STAT_SPIF))
371                         continue;
372                 while (!(read_STAT() & BIT_STAT_RXS))
373                         continue;
374                 *(u8 *) (drv_data->rx) = read_RDBR();
375                 ++drv_data->rx;
376                 ++drv_data->tx;
377         }
378 }
379
380 static void u8_cs_chg_duplex(struct driver_data *drv_data)
381 {
382         struct chip_data *chip = drv_data->cur_chip;
383
384         while (drv_data->rx < drv_data->rx_end) {
385                 write_FLAG(chip->flag);
386                 SSYNC();
387
388                 write_TDBR(*(u8 *) (drv_data->tx));
389                 while (!(read_STAT() & BIT_STAT_SPIF))
390                         continue;
391                 while (!(read_STAT() & BIT_STAT_RXS))
392                         continue;
393                 *(u8 *) (drv_data->rx) = read_RDBR();
394                 write_FLAG(0xFF00 | chip->flag);
395                 SSYNC();
396                 if (chip->cs_chg_udelay)
397                         udelay(chip->cs_chg_udelay);
398                 ++drv_data->rx;
399                 ++drv_data->tx;
400         }
401         write_FLAG(0xFF00);
402         SSYNC();
403 }
404
405 static void u16_writer(struct driver_data *drv_data)
406 {
407         pr_debug("cr16 is 0x%x\n", read_STAT());
408         while (drv_data->tx < drv_data->tx_end) {
409                 write_TDBR(*(u16 *) (drv_data->tx));
410                 while ((read_STAT() & BIT_STAT_TXS))
411                         continue;
412                 drv_data->tx += 2;
413         }
414
415         /* poll for SPI completion before returning */
416         while (!(read_STAT() & BIT_STAT_SPIF))
417                 continue;
418 }
419
420 static void u16_cs_chg_writer(struct driver_data *drv_data)
421 {
422         struct chip_data *chip = drv_data->cur_chip;
423
424         while (drv_data->tx < drv_data->tx_end) {
425                 write_FLAG(chip->flag);
426                 SSYNC();
427
428                 write_TDBR(*(u16 *) (drv_data->tx));
429                 while ((read_STAT() & BIT_STAT_TXS))
430                         continue;
431                 while (!(read_STAT() & BIT_STAT_SPIF))
432                         continue;
433                 write_FLAG(0xFF00 | chip->flag);
434                 SSYNC();
435                 if (chip->cs_chg_udelay)
436                         udelay(chip->cs_chg_udelay);
437                 drv_data->tx += 2;
438         }
439         write_FLAG(0xFF00);
440         SSYNC();
441 }
442
443 static void u16_reader(struct driver_data *drv_data)
444 {
445         pr_debug("cr-16 is 0x%x\n", read_STAT());
446         dummy_read();
447
448         while (drv_data->rx < (drv_data->rx_end - 2)) {
449                 while (!(read_STAT() & BIT_STAT_RXS))
450                         continue;
451                 *(u16 *) (drv_data->rx) = read_RDBR();
452                 drv_data->rx += 2;
453         }
454
455         while (!(read_STAT() & BIT_STAT_RXS))
456                 continue;
457         *(u16 *) (drv_data->rx) = read_SHAW();
458         drv_data->rx += 2;
459 }
460
461 static void u16_cs_chg_reader(struct driver_data *drv_data)
462 {
463         struct chip_data *chip = drv_data->cur_chip;
464
465         while (drv_data->rx < drv_data->rx_end) {
466                 write_FLAG(chip->flag);
467                 SSYNC();
468
469                 read_RDBR();    /* kick off */
470                 while (!(read_STAT() & BIT_STAT_RXS))
471                         continue;
472                 while (!(read_STAT() & BIT_STAT_SPIF))
473                         continue;
474                 *(u16 *) (drv_data->rx) = read_SHAW();
475                 write_FLAG(0xFF00 | chip->flag);
476                 SSYNC();
477                 if (chip->cs_chg_udelay)
478                         udelay(chip->cs_chg_udelay);
479                 drv_data->rx += 2;
480         }
481         write_FLAG(0xFF00);
482         SSYNC();
483 }
484
485 static void u16_duplex(struct driver_data *drv_data)
486 {
487         /* in duplex mode, clk is triggered by writing of TDBR */
488         while (drv_data->tx < drv_data->tx_end) {
489                 write_TDBR(*(u16 *) (drv_data->tx));
490                 while (!(read_STAT() & BIT_STAT_SPIF))
491                         continue;
492                 while (!(read_STAT() & BIT_STAT_RXS))
493                         continue;
494                 *(u16 *) (drv_data->rx) = read_RDBR();
495                 drv_data->rx += 2;
496                 drv_data->tx += 2;
497         }
498 }
499
500 static void u16_cs_chg_duplex(struct driver_data *drv_data)
501 {
502         struct chip_data *chip = drv_data->cur_chip;
503
504         while (drv_data->tx < drv_data->tx_end) {
505                 write_FLAG(chip->flag);
506                 SSYNC();
507
508                 write_TDBR(*(u16 *) (drv_data->tx));
509                 while (!(read_STAT() & BIT_STAT_SPIF))
510                         continue;
511                 while (!(read_STAT() & BIT_STAT_RXS))
512                         continue;
513                 *(u16 *) (drv_data->rx) = read_RDBR();
514                 write_FLAG(0xFF00 | chip->flag);
515                 SSYNC();
516                 if (chip->cs_chg_udelay)
517                         udelay(chip->cs_chg_udelay);
518                 drv_data->rx += 2;
519                 drv_data->tx += 2;
520         }
521         write_FLAG(0xFF00);
522         SSYNC();
523 }
524
525 /* test if ther is more transfer to be done */
526 static void *next_transfer(struct driver_data *drv_data)
527 {
528         struct spi_message *msg = drv_data->cur_msg;
529         struct spi_transfer *trans = drv_data->cur_transfer;
530
531         /* Move to next transfer */
532         if (trans->transfer_list.next != &msg->transfers) {
533                 drv_data->cur_transfer =
534                     list_entry(trans->transfer_list.next,
535                                struct spi_transfer, transfer_list);
536                 return RUNNING_STATE;
537         } else
538                 return DONE_STATE;
539 }
540
541 /*
542  * caller already set message->status;
543  * dma and pio irqs are blocked give finished message back
544  */
545 static void giveback(struct driver_data *drv_data)
546 {
547         struct spi_transfer *last_transfer;
548         unsigned long flags;
549         struct spi_message *msg;
550
551         spin_lock_irqsave(&drv_data->lock, flags);
552         msg = drv_data->cur_msg;
553         drv_data->cur_msg = NULL;
554         drv_data->cur_transfer = NULL;
555         drv_data->cur_chip = NULL;
556         queue_work(drv_data->workqueue, &drv_data->pump_messages);
557         spin_unlock_irqrestore(&drv_data->lock, flags);
558
559         last_transfer = list_entry(msg->transfers.prev,
560                                    struct spi_transfer, transfer_list);
561
562         msg->state = NULL;
563
564         /* disable chip select signal. And not stop spi in autobuffer mode */
565         if (drv_data->tx_dma != 0xFFFF) {
566                 write_FLAG(0xFF00);
567                 bfin_spi_disable(drv_data);
568         }
569
570         if (msg->complete)
571                 msg->complete(msg->context);
572 }
573
574 static irqreturn_t dma_irq_handler(int irq, void *dev_id, struct pt_regs *regs)
575 {
576         struct driver_data *drv_data = (struct driver_data *)dev_id;
577         struct spi_message *msg = drv_data->cur_msg;
578
579         pr_debug("in dma_irq_handler\n");
580         clear_dma_irqstat(CH_SPI);
581
582         /*
583          * wait for the last transaction shifted out.  yes, these two
584          * while loops are supposed to be the same (see the HRM).
585          */
586         if (drv_data->tx != NULL) {
587                 while (bfin_read_SPI_STAT() & TXS)
588                         continue;
589                 while (bfin_read_SPI_STAT() & TXS)
590                         continue;
591         }
592
593         while (!(bfin_read_SPI_STAT() & SPIF))
594                 continue;
595
596         bfin_spi_disable(drv_data);
597
598         msg->actual_length += drv_data->len_in_bytes;
599
600         /* Move to next transfer */
601         msg->state = next_transfer(drv_data);
602
603         /* Schedule transfer tasklet */
604         tasklet_schedule(&drv_data->pump_transfers);
605
606         /* free the irq handler before next transfer */
607         pr_debug("disable dma channel irq%d\n", CH_SPI);
608         dma_disable_irq(CH_SPI);
609
610         return IRQ_HANDLED;
611 }
612
613 static void pump_transfers(unsigned long data)
614 {
615         struct driver_data *drv_data = (struct driver_data *)data;
616         struct spi_message *message = NULL;
617         struct spi_transfer *transfer = NULL;
618         struct spi_transfer *previous = NULL;
619         struct chip_data *chip = NULL;
620         u16 cr, width, dma_width, dma_config;
621         u32 tranf_success = 1;
622
623         /* Get current state information */
624         message = drv_data->cur_msg;
625         transfer = drv_data->cur_transfer;
626         chip = drv_data->cur_chip;
627
628         /*
629          * if msg is error or done, report it back using complete() callback
630          */
631
632          /* Handle for abort */
633         if (message->state == ERROR_STATE) {
634                 message->status = -EIO;
635                 giveback(drv_data);
636                 return;
637         }
638
639         /* Handle end of message */
640         if (message->state == DONE_STATE) {
641                 message->status = 0;
642                 giveback(drv_data);
643                 return;
644         }
645
646         /* Delay if requested at end of transfer */
647         if (message->state == RUNNING_STATE) {
648                 previous = list_entry(transfer->transfer_list.prev,
649                                       struct spi_transfer, transfer_list);
650                 if (previous->delay_usecs)
651                         udelay(previous->delay_usecs);
652         }
653
654         /* Setup the transfer state based on the type of transfer */
655         if (flush(drv_data) == 0) {
656                 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
657                 message->status = -EIO;
658                 giveback(drv_data);
659                 return;
660         }
661
662         if (transfer->tx_buf != NULL) {
663                 drv_data->tx = (void *)transfer->tx_buf;
664                 drv_data->tx_end = drv_data->tx + transfer->len;
665                 pr_debug("tx_buf is %p, tx_end is %p\n", transfer->tx_buf,
666                          drv_data->tx_end);
667         } else {
668                 drv_data->tx = NULL;
669         }
670
671         if (transfer->rx_buf != NULL) {
672                 drv_data->rx = transfer->rx_buf;
673                 drv_data->rx_end = drv_data->rx + transfer->len;
674                 pr_debug("rx_buf is %p, rx_end is %p\n", transfer->rx_buf,
675                          drv_data->rx_end);
676         } else {
677                 drv_data->rx = NULL;
678         }
679
680         drv_data->rx_dma = transfer->rx_dma;
681         drv_data->tx_dma = transfer->tx_dma;
682         drv_data->len_in_bytes = transfer->len;
683
684         width = chip->width;
685         if (width == CFG_SPI_WORDSIZE16) {
686                 drv_data->len = (transfer->len) >> 1;
687         } else {
688                 drv_data->len = transfer->len;
689         }
690         drv_data->write = drv_data->tx ? chip->write : null_writer;
691         drv_data->read = drv_data->rx ? chip->read : null_reader;
692         drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
693         pr_debug
694             ("transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
695              drv_data->write, chip->write, null_writer);
696
697         /* speed and width has been set on per message */
698         message->state = RUNNING_STATE;
699         dma_config = 0;
700
701         /* restore spi status for each spi transfer */
702         if (transfer->speed_hz) {
703                 write_BAUD(hz_to_spi_baud(transfer->speed_hz));
704         } else {
705                 write_BAUD(chip->baud);
706         }
707         write_FLAG(chip->flag);
708
709         pr_debug("now pumping a transfer: width is %d, len is %d\n", width,
710                  transfer->len);
711
712         /*
713          * Try to map dma buffer and do a dma transfer if
714          * successful use different way to r/w according to
715          * drv_data->cur_chip->enable_dma
716          */
717         if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
718
719                 write_STAT(BIT_STAT_CLR);
720                 disable_dma(CH_SPI);
721                 clear_dma_irqstat(CH_SPI);
722                 bfin_spi_disable(drv_data);
723
724                 /* config dma channel */
725                 pr_debug("doing dma transfer\n");
726                 if (width == CFG_SPI_WORDSIZE16) {
727                         set_dma_x_count(CH_SPI, drv_data->len);
728                         set_dma_x_modify(CH_SPI, 2);
729                         dma_width = WDSIZE_16;
730                 } else {
731                         set_dma_x_count(CH_SPI, drv_data->len);
732                         set_dma_x_modify(CH_SPI, 1);
733                         dma_width = WDSIZE_8;
734                 }
735
736                 /* set transfer width,direction. And enable spi */
737                 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
738
739                 /* dirty hack for autobuffer DMA mode */
740                 if (drv_data->tx_dma == 0xFFFF) {
741                         pr_debug("doing autobuffer DMA out.\n");
742
743                         /* no irq in autobuffer mode */
744                         dma_config =
745                             (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
746                         set_dma_config(CH_SPI, dma_config);
747                         set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
748                         enable_dma(CH_SPI);
749                         write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
750                                    (CFG_SPI_ENABLE << 14));
751
752                         /* just return here, there can only be one transfer in this mode */
753                         message->status = 0;
754                         giveback(drv_data);
755                         return;
756                 }
757
758                 /* In dma mode, rx or tx must be NULL in one transfer */
759                 if (drv_data->rx != NULL) {
760                         /* set transfer mode, and enable SPI */
761                         pr_debug("doing DMA in.\n");
762
763                         /* disable SPI before write to TDBR */
764                         write_CTRL(cr & ~BIT_CTL_ENABLE);
765
766                         /* clear tx reg soformer data is not shifted out */
767                         write_TDBR(0xFF);
768
769                         set_dma_x_count(CH_SPI, drv_data->len);
770
771                         /* start dma */
772                         dma_enable_irq(CH_SPI);
773                         dma_config = (WNR | RESTART | dma_width | DI_EN);
774                         set_dma_config(CH_SPI, dma_config);
775                         set_dma_start_addr(CH_SPI, (unsigned long)drv_data->rx);
776                         enable_dma(CH_SPI);
777
778                         cr |=
779                             CFG_SPI_DMAREAD | (width << 8) | (CFG_SPI_ENABLE <<
780                                                               14);
781                         /* set transfer mode, and enable SPI */
782                         write_CTRL(cr);
783                 } else if (drv_data->tx != NULL) {
784                         pr_debug("doing DMA out.\n");
785
786                         /* start dma */
787                         dma_enable_irq(CH_SPI);
788                         dma_config = (RESTART | dma_width | DI_EN);
789                         set_dma_config(CH_SPI, dma_config);
790                         set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
791                         enable_dma(CH_SPI);
792
793                         write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
794                                    (CFG_SPI_ENABLE << 14));
795
796                 }
797         } else {
798                 /* IO mode write then read */
799                 pr_debug("doing IO transfer\n");
800
801                 write_STAT(BIT_STAT_CLR);
802
803                 if (drv_data->tx != NULL && drv_data->rx != NULL) {
804                         /* full duplex mode */
805                         BUG_ON((drv_data->tx_end - drv_data->tx) !=
806                                (drv_data->rx_end - drv_data->rx));
807                         cr = (read_CTRL() & (~BIT_CTL_TIMOD));  /* clear the TIMOD bits */
808                         cr |=
809                             CFG_SPI_WRITE | (width << 8) | (CFG_SPI_ENABLE <<
810                                                             14);
811                         pr_debug("IO duplex: cr is 0x%x\n", cr);
812
813                         write_CTRL(cr);
814                         SSYNC();
815
816                         drv_data->duplex(drv_data);
817
818                         if (drv_data->tx != drv_data->tx_end)
819                                 tranf_success = 0;
820                 } else if (drv_data->tx != NULL) {
821                         /* write only half duplex */
822                         cr = (read_CTRL() & (~BIT_CTL_TIMOD));  /* clear the TIMOD bits */
823                         cr |=
824                             CFG_SPI_WRITE | (width << 8) | (CFG_SPI_ENABLE <<
825                                                             14);
826                         pr_debug("IO write: cr is 0x%x\n", cr);
827
828                         write_CTRL(cr);
829                         SSYNC();
830
831                         drv_data->write(drv_data);
832
833                         if (drv_data->tx != drv_data->tx_end)
834                                 tranf_success = 0;
835                 } else if (drv_data->rx != NULL) {
836                         /* read only half duplex */
837                         cr = (read_CTRL() & (~BIT_CTL_TIMOD));  /* cleare the TIMOD bits */
838                         cr |=
839                             CFG_SPI_READ | (width << 8) | (CFG_SPI_ENABLE <<
840                                                            14);
841                         pr_debug("IO read: cr is 0x%x\n", cr);
842
843                         write_CTRL(cr);
844                         SSYNC();
845
846                         drv_data->read(drv_data);
847                         if (drv_data->rx != drv_data->rx_end)
848                                 tranf_success = 0;
849                 }
850
851                 if (!tranf_success) {
852                         pr_debug("IO write error!\n");
853                         message->state = ERROR_STATE;
854                 } else {
855                         /* Update total byte transfered */
856                         message->actual_length += drv_data->len;
857
858                         /* Move to next transfer of this msg */
859                         message->state = next_transfer(drv_data);
860                 }
861
862                 /* Schedule next transfer tasklet */
863                 tasklet_schedule(&drv_data->pump_transfers);
864
865         }
866 }
867
868 /* pop a msg from queue and kick off real transfer */
869 static void pump_messages(struct work_struct *work)
870 {
871         struct driver_data *drv_data = container_of(work, struct driver_data, pump_messages);
872         unsigned long flags;
873
874         /* Lock queue and check for queue work */
875         spin_lock_irqsave(&drv_data->lock, flags);
876         if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
877                 /* pumper kicked off but no work to do */
878                 drv_data->busy = 0;
879                 spin_unlock_irqrestore(&drv_data->lock, flags);
880                 return;
881         }
882
883         /* Make sure we are not already running a message */
884         if (drv_data->cur_msg) {
885                 spin_unlock_irqrestore(&drv_data->lock, flags);
886                 return;
887         }
888
889         /* Extract head of queue */
890         drv_data->cur_msg = list_entry(drv_data->queue.next,
891                                        struct spi_message, queue);
892         list_del_init(&drv_data->cur_msg->queue);
893
894         /* Initial message state */
895         drv_data->cur_msg->state = START_STATE;
896         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
897                                             struct spi_transfer, transfer_list);
898
899         /* Setup the SSP using the per chip configuration */
900         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
901         restore_state(drv_data);
902         pr_debug
903             ("got a message to pump, state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
904              drv_data->cur_chip->baud, drv_data->cur_chip->flag,
905              drv_data->cur_chip->ctl_reg);
906         pr_debug("the first transfer len is %d\n", drv_data->cur_transfer->len);
907
908         /* Mark as busy and launch transfers */
909         tasklet_schedule(&drv_data->pump_transfers);
910
911         drv_data->busy = 1;
912         spin_unlock_irqrestore(&drv_data->lock, flags);
913 }
914
915 /*
916  * got a msg to transfer, queue it in drv_data->queue.
917  * And kick off message pumper
918  */
919 static int transfer(struct spi_device *spi, struct spi_message *msg)
920 {
921         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
922         unsigned long flags;
923
924         spin_lock_irqsave(&drv_data->lock, flags);
925
926         if (drv_data->run == QUEUE_STOPPED) {
927                 spin_unlock_irqrestore(&drv_data->lock, flags);
928                 return -ESHUTDOWN;
929         }
930
931         msg->actual_length = 0;
932         msg->status = -EINPROGRESS;
933         msg->state = START_STATE;
934
935         pr_debug("adding an msg in transfer() \n");
936         list_add_tail(&msg->queue, &drv_data->queue);
937
938         if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
939                 queue_work(drv_data->workqueue, &drv_data->pump_messages);
940
941         spin_unlock_irqrestore(&drv_data->lock, flags);
942
943         return 0;
944 }
945
946 /* first setup for new devices */
947 static int setup(struct spi_device *spi)
948 {
949         struct bfin5xx_spi_chip *chip_info = NULL;
950         struct chip_data *chip;
951         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
952         u8 spi_flg;
953
954         /* Abort device setup if requested features are not supported */
955         if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
956                 dev_err(&spi->dev, "requested mode not fully supported\n");
957                 return -EINVAL;
958         }
959
960         /* Zero (the default) here means 8 bits */
961         if (!spi->bits_per_word)
962                 spi->bits_per_word = 8;
963
964         if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
965                 return -EINVAL;
966
967         /* Only alloc (or use chip_info) on first setup */
968         chip = spi_get_ctldata(spi);
969         if (chip == NULL) {
970                 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
971                 if (!chip)
972                         return -ENOMEM;
973
974                 chip->enable_dma = 0;
975                 chip_info = spi->controller_data;
976         }
977
978         /* chip_info isn't always needed */
979         if (chip_info) {
980                 chip->enable_dma = chip_info->enable_dma != 0
981                     && drv_data->master_info->enable_dma;
982                 chip->ctl_reg = chip_info->ctl_reg;
983                 chip->bits_per_word = chip_info->bits_per_word;
984                 chip->cs_change_per_word = chip_info->cs_change_per_word;
985                 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
986         }
987
988         /* translate common spi framework into our register */
989         if (spi->mode & SPI_CPOL)
990                 chip->ctl_reg |= CPOL;
991         if (spi->mode & SPI_CPHA)
992                 chip->ctl_reg |= CPHA;
993         if (spi->mode & SPI_LSB_FIRST)
994                 chip->ctl_reg |= LSBF;
995         /* we dont support running in slave mode (yet?) */
996         chip->ctl_reg |= MSTR;
997
998         /*
999          * if any one SPI chip is registered and wants DMA, request the
1000          * DMA channel for it
1001          */
1002         if (chip->enable_dma && !dma_requested) {
1003                 /* register dma irq handler */
1004                 if (request_dma(CH_SPI, "BF53x_SPI_DMA") < 0) {
1005                         pr_debug
1006                             ("Unable to request BlackFin SPI DMA channel\n");
1007                         return -ENODEV;
1008                 }
1009                 if (set_dma_callback(CH_SPI, (void *)dma_irq_handler, drv_data)
1010                     < 0) {
1011                         pr_debug("Unable to set dma callback\n");
1012                         return -EPERM;
1013                 }
1014                 dma_disable_irq(CH_SPI);
1015                 dma_requested = 1;
1016         }
1017
1018         /*
1019          * Notice: for blackfin, the speed_hz is the value of register
1020          * SPI_BAUD, not the real baudrate
1021          */
1022         chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1023         spi_flg = ~(1 << (spi->chip_select));
1024         chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
1025         chip->chip_select_num = spi->chip_select;
1026
1027         switch (chip->bits_per_word) {
1028         case 8:
1029                 chip->n_bytes = 1;
1030                 chip->width = CFG_SPI_WORDSIZE8;
1031                 chip->read = chip->cs_change_per_word ?
1032                         u8_cs_chg_reader : u8_reader;
1033                 chip->write = chip->cs_change_per_word ?
1034                         u8_cs_chg_writer : u8_writer;
1035                 chip->duplex = chip->cs_change_per_word ?
1036                         u8_cs_chg_duplex : u8_duplex;
1037                 break;
1038
1039         case 16:
1040                 chip->n_bytes = 2;
1041                 chip->width = CFG_SPI_WORDSIZE16;
1042                 chip->read = chip->cs_change_per_word ?
1043                         u16_cs_chg_reader : u16_reader;
1044                 chip->write = chip->cs_change_per_word ?
1045                         u16_cs_chg_writer : u16_writer;
1046                 chip->duplex = chip->cs_change_per_word ?
1047                         u16_cs_chg_duplex : u16_duplex;
1048                 break;
1049
1050         default:
1051                 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1052                                 chip->bits_per_word);
1053                 kfree(chip);
1054                 return -ENODEV;
1055         }
1056
1057         pr_debug("setup spi chip %s, width is %d, dma is %d,",
1058                         spi->modalias, chip->width, chip->enable_dma);
1059         pr_debug("ctl_reg is 0x%x, flag_reg is 0x%x\n",
1060                         chip->ctl_reg, chip->flag);
1061
1062         spi_set_ctldata(spi, chip);
1063
1064         return 0;
1065 }
1066
1067 /*
1068  * callback for spi framework.
1069  * clean driver specific data
1070  */
1071 static void cleanup(const struct spi_device *spi)
1072 {
1073         struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
1074
1075         kfree(chip);
1076 }
1077
1078 static inline int init_queue(struct driver_data *drv_data)
1079 {
1080         INIT_LIST_HEAD(&drv_data->queue);
1081         spin_lock_init(&drv_data->lock);
1082
1083         drv_data->run = QUEUE_STOPPED;
1084         drv_data->busy = 0;
1085
1086         /* init transfer tasklet */
1087         tasklet_init(&drv_data->pump_transfers,
1088                      pump_transfers, (unsigned long)drv_data);
1089
1090         /* init messages workqueue */
1091         INIT_WORK(&drv_data->pump_messages, pump_messages);
1092         drv_data->workqueue =
1093             create_singlethread_workqueue(drv_data->master->cdev.dev->bus_id);
1094         if (drv_data->workqueue == NULL)
1095                 return -EBUSY;
1096
1097         return 0;
1098 }
1099
1100 static inline int start_queue(struct driver_data *drv_data)
1101 {
1102         unsigned long flags;
1103
1104         spin_lock_irqsave(&drv_data->lock, flags);
1105
1106         if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1107                 spin_unlock_irqrestore(&drv_data->lock, flags);
1108                 return -EBUSY;
1109         }
1110
1111         drv_data->run = QUEUE_RUNNING;
1112         drv_data->cur_msg = NULL;
1113         drv_data->cur_transfer = NULL;
1114         drv_data->cur_chip = NULL;
1115         spin_unlock_irqrestore(&drv_data->lock, flags);
1116
1117         queue_work(drv_data->workqueue, &drv_data->pump_messages);
1118
1119         return 0;
1120 }
1121
1122 static inline int stop_queue(struct driver_data *drv_data)
1123 {
1124         unsigned long flags;
1125         unsigned limit = 500;
1126         int status = 0;
1127
1128         spin_lock_irqsave(&drv_data->lock, flags);
1129
1130         /*
1131          * This is a bit lame, but is optimized for the common execution path.
1132          * A wait_queue on the drv_data->busy could be used, but then the common
1133          * execution path (pump_messages) would be required to call wake_up or
1134          * friends on every SPI message. Do this instead
1135          */
1136         drv_data->run = QUEUE_STOPPED;
1137         while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1138                 spin_unlock_irqrestore(&drv_data->lock, flags);
1139                 msleep(10);
1140                 spin_lock_irqsave(&drv_data->lock, flags);
1141         }
1142
1143         if (!list_empty(&drv_data->queue) || drv_data->busy)
1144                 status = -EBUSY;
1145
1146         spin_unlock_irqrestore(&drv_data->lock, flags);
1147
1148         return status;
1149 }
1150
1151 static inline int destroy_queue(struct driver_data *drv_data)
1152 {
1153         int status;
1154
1155         status = stop_queue(drv_data);
1156         if (status != 0)
1157                 return status;
1158
1159         destroy_workqueue(drv_data->workqueue);
1160
1161         return 0;
1162 }
1163
1164 static int __init bfin5xx_spi_probe(struct platform_device *pdev)
1165 {
1166         struct device *dev = &pdev->dev;
1167         struct bfin5xx_spi_master *platform_info;
1168         struct spi_master *master;
1169         struct driver_data *drv_data = 0;
1170         int status = 0;
1171
1172         platform_info = dev->platform_data;
1173
1174         /* Allocate master with space for drv_data */
1175         master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1176         if (!master) {
1177                 dev_err(&pdev->dev, "can not alloc spi_master\n");
1178                 return -ENOMEM;
1179         }
1180         drv_data = spi_master_get_devdata(master);
1181         drv_data->master = master;
1182         drv_data->master_info = platform_info;
1183         drv_data->pdev = pdev;
1184
1185         master->bus_num = pdev->id;
1186         master->num_chipselect = platform_info->num_chipselect;
1187         master->cleanup = cleanup;
1188         master->setup = setup;
1189         master->transfer = transfer;
1190
1191         /* Initial and start queue */
1192         status = init_queue(drv_data);
1193         if (status != 0) {
1194                 dev_err(&pdev->dev, "problem initializing queue\n");
1195                 goto out_error_queue_alloc;
1196         }
1197         status = start_queue(drv_data);
1198         if (status != 0) {
1199                 dev_err(&pdev->dev, "problem starting queue\n");
1200                 goto out_error_queue_alloc;
1201         }
1202
1203         /* Register with the SPI framework */
1204         platform_set_drvdata(pdev, drv_data);
1205         status = spi_register_master(master);
1206         if (status != 0) {
1207                 dev_err(&pdev->dev, "problem registering spi master\n");
1208                 goto out_error_queue_alloc;
1209         }
1210         pr_debug("controller probe successfully\n");
1211         return status;
1212
1213       out_error_queue_alloc:
1214         destroy_queue(drv_data);
1215         spi_master_put(master);
1216         return status;
1217 }
1218
1219 /* stop hardware and remove the driver */
1220 static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
1221 {
1222         struct driver_data *drv_data = platform_get_drvdata(pdev);
1223         int status = 0;
1224
1225         if (!drv_data)
1226                 return 0;
1227
1228         /* Remove the queue */
1229         status = destroy_queue(drv_data);
1230         if (status != 0)
1231                 return status;
1232
1233         /* Disable the SSP at the peripheral and SOC level */
1234         bfin_spi_disable(drv_data);
1235
1236         /* Release DMA */
1237         if (drv_data->master_info->enable_dma) {
1238                 if (dma_channel_active(CH_SPI))
1239                         free_dma(CH_SPI);
1240         }
1241
1242         /* Disconnect from the SPI framework */
1243         spi_unregister_master(drv_data->master);
1244
1245         /* Prevent double remove */
1246         platform_set_drvdata(pdev, NULL);
1247
1248         return 0;
1249 }
1250
1251 #ifdef CONFIG_PM
1252 static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1253 {
1254         struct driver_data *drv_data = platform_get_drvdata(pdev);
1255         int status = 0;
1256
1257         status = stop_queue(drv_data);
1258         if (status != 0)
1259                 return status;
1260
1261         /* stop hardware */
1262         bfin_spi_disable(drv_data);
1263
1264         return 0;
1265 }
1266
1267 static int bfin5xx_spi_resume(struct platform_device *pdev)
1268 {
1269         struct driver_data *drv_data = platform_get_drvdata(pdev);
1270         int status = 0;
1271
1272         /* Enable the SPI interface */
1273         bfin_spi_enable(drv_data);
1274
1275         /* Start the queue running */
1276         status = start_queue(drv_data);
1277         if (status != 0) {
1278                 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1279                 return status;
1280         }
1281
1282         return 0;
1283 }
1284 #else
1285 #define bfin5xx_spi_suspend NULL
1286 #define bfin5xx_spi_resume NULL
1287 #endif                          /* CONFIG_PM */
1288
1289 static struct platform_driver bfin5xx_spi_driver = {
1290         .driver = {
1291                    .name = "bfin-spi-master",
1292                    .bus = &platform_bus_type,
1293                    .owner = THIS_MODULE,
1294                    },
1295         .probe = bfin5xx_spi_probe,
1296         .remove = __devexit_p(bfin5xx_spi_remove),
1297         .suspend = bfin5xx_spi_suspend,
1298         .resume = bfin5xx_spi_resume,
1299 };
1300
1301 static int __init bfin5xx_spi_init(void)
1302 {
1303         return platform_driver_register(&bfin5xx_spi_driver);
1304 }
1305
1306 module_init(bfin5xx_spi_init);
1307
1308 static void __exit bfin5xx_spi_exit(void)
1309 {
1310         platform_driver_unregister(&bfin5xx_spi_driver);
1311 }
1312
1313 module_exit(bfin5xx_spi_exit);