sched: make early bootup sched_clock() use safer
[wrt350n-kernel.git] / drivers / spi / spi_bfin5xx.c
blobd853fceb6bf01bebfa9f3386a6dee184dbc21c20
1 /*
2 * Blackfin On-Chip SPI Driver
4 * Copyright 2004-2007 Analog Devices Inc.
6 * Enter bugs at http://blackfin.uclinux.org/
8 * Licensed under the GPL-2 or later.
9 */
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/io.h>
16 #include <linux/ioport.h>
17 #include <linux/irq.h>
18 #include <linux/errno.h>
19 #include <linux/interrupt.h>
20 #include <linux/platform_device.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/spi/spi.h>
23 #include <linux/workqueue.h>
25 #include <asm/dma.h>
26 #include <asm/portmux.h>
27 #include <asm/bfin5xx_spi.h>
29 #define DRV_NAME "bfin-spi"
30 #define DRV_AUTHOR "Bryan Wu, Luke Yang"
31 #define DRV_DESC "Blackfin BF5xx on-chip SPI Controller Driver"
32 #define DRV_VERSION "1.0"
34 MODULE_AUTHOR(DRV_AUTHOR);
35 MODULE_DESCRIPTION(DRV_DESC);
36 MODULE_LICENSE("GPL");
38 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07) == 0)
40 #define START_STATE ((void *)0)
41 #define RUNNING_STATE ((void *)1)
42 #define DONE_STATE ((void *)2)
43 #define ERROR_STATE ((void *)-1)
44 #define QUEUE_RUNNING 0
45 #define QUEUE_STOPPED 1
47 struct driver_data {
48 /* Driver model hookup */
49 struct platform_device *pdev;
51 /* SPI framework hookup */
52 struct spi_master *master;
54 /* Regs base of SPI controller */
55 void __iomem *regs_base;
57 /* Pin request list */
58 u16 *pin_req;
60 /* BFIN hookup */
61 struct bfin5xx_spi_master *master_info;
63 /* Driver message queue */
64 struct workqueue_struct *workqueue;
65 struct work_struct pump_messages;
66 spinlock_t lock;
67 struct list_head queue;
68 int busy;
69 int run;
71 /* Message Transfer pump */
72 struct tasklet_struct pump_transfers;
74 /* Current message transfer state info */
75 struct spi_message *cur_msg;
76 struct spi_transfer *cur_transfer;
77 struct chip_data *cur_chip;
78 size_t len_in_bytes;
79 size_t len;
80 void *tx;
81 void *tx_end;
82 void *rx;
83 void *rx_end;
85 /* DMA stuffs */
86 int dma_channel;
87 int dma_mapped;
88 int dma_requested;
89 dma_addr_t rx_dma;
90 dma_addr_t tx_dma;
92 size_t rx_map_len;
93 size_t tx_map_len;
94 u8 n_bytes;
95 int cs_change;
96 void (*write) (struct driver_data *);
97 void (*read) (struct driver_data *);
98 void (*duplex) (struct driver_data *);
101 struct chip_data {
102 u16 ctl_reg;
103 u16 baud;
104 u16 flag;
106 u8 chip_select_num;
107 u8 n_bytes;
108 u8 width; /* 0 or 1 */
109 u8 enable_dma;
110 u8 bits_per_word; /* 8 or 16 */
111 u8 cs_change_per_word;
112 u16 cs_chg_udelay; /* Some devices require > 255usec delay */
113 void (*write) (struct driver_data *);
114 void (*read) (struct driver_data *);
115 void (*duplex) (struct driver_data *);
118 #define DEFINE_SPI_REG(reg, off) \
119 static inline u16 read_##reg(struct driver_data *drv_data) \
120 { return bfin_read16(drv_data->regs_base + off); } \
121 static inline void write_##reg(struct driver_data *drv_data, u16 v) \
122 { bfin_write16(drv_data->regs_base + off, v); }
124 DEFINE_SPI_REG(CTRL, 0x00)
125 DEFINE_SPI_REG(FLAG, 0x04)
126 DEFINE_SPI_REG(STAT, 0x08)
127 DEFINE_SPI_REG(TDBR, 0x0C)
128 DEFINE_SPI_REG(RDBR, 0x10)
129 DEFINE_SPI_REG(BAUD, 0x14)
130 DEFINE_SPI_REG(SHAW, 0x18)
132 static void bfin_spi_enable(struct driver_data *drv_data)
134 u16 cr;
136 cr = read_CTRL(drv_data);
137 write_CTRL(drv_data, (cr | BIT_CTL_ENABLE));
140 static void bfin_spi_disable(struct driver_data *drv_data)
142 u16 cr;
144 cr = read_CTRL(drv_data);
145 write_CTRL(drv_data, (cr & (~BIT_CTL_ENABLE)));
148 /* Caculate the SPI_BAUD register value based on input HZ */
149 static u16 hz_to_spi_baud(u32 speed_hz)
151 u_long sclk = get_sclk();
152 u16 spi_baud = (sclk / (2 * speed_hz));
154 if ((sclk % (2 * speed_hz)) > 0)
155 spi_baud++;
157 return spi_baud;
160 static int flush(struct driver_data *drv_data)
162 unsigned long limit = loops_per_jiffy << 1;
164 /* wait for stop and clear stat */
165 while (!(read_STAT(drv_data) & BIT_STAT_SPIF) && limit--)
166 cpu_relax();
168 write_STAT(drv_data, BIT_STAT_CLR);
170 return limit;
173 /* Chip select operation functions for cs_change flag */
174 static void cs_active(struct driver_data *drv_data, struct chip_data *chip)
176 u16 flag = read_FLAG(drv_data);
178 flag |= chip->flag;
179 flag &= ~(chip->flag << 8);
181 write_FLAG(drv_data, flag);
184 static void cs_deactive(struct driver_data *drv_data, struct chip_data *chip)
186 u16 flag = read_FLAG(drv_data);
188 flag |= (chip->flag << 8);
190 write_FLAG(drv_data, flag);
192 /* Move delay here for consistency */
193 if (chip->cs_chg_udelay)
194 udelay(chip->cs_chg_udelay);
197 #define MAX_SPI_SSEL 7
199 /* stop controller and re-config current chip*/
200 static void restore_state(struct driver_data *drv_data)
202 struct chip_data *chip = drv_data->cur_chip;
204 /* Clear status and disable clock */
205 write_STAT(drv_data, BIT_STAT_CLR);
206 bfin_spi_disable(drv_data);
207 dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
209 /* Load the registers */
210 write_CTRL(drv_data, chip->ctl_reg);
211 write_BAUD(drv_data, chip->baud);
213 bfin_spi_enable(drv_data);
214 cs_active(drv_data, chip);
217 /* used to kick off transfer in rx mode */
218 static unsigned short dummy_read(struct driver_data *drv_data)
220 unsigned short tmp;
221 tmp = read_RDBR(drv_data);
222 return tmp;
225 static void null_writer(struct driver_data *drv_data)
227 u8 n_bytes = drv_data->n_bytes;
229 while (drv_data->tx < drv_data->tx_end) {
230 write_TDBR(drv_data, 0);
231 while ((read_STAT(drv_data) & BIT_STAT_TXS))
232 cpu_relax();
233 drv_data->tx += n_bytes;
237 static void null_reader(struct driver_data *drv_data)
239 u8 n_bytes = drv_data->n_bytes;
240 dummy_read(drv_data);
242 while (drv_data->rx < drv_data->rx_end) {
243 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
244 cpu_relax();
245 dummy_read(drv_data);
246 drv_data->rx += n_bytes;
250 static void u8_writer(struct driver_data *drv_data)
252 dev_dbg(&drv_data->pdev->dev,
253 "cr8-s is 0x%x\n", read_STAT(drv_data));
255 while (drv_data->tx < drv_data->tx_end) {
256 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
257 while (read_STAT(drv_data) & BIT_STAT_TXS)
258 cpu_relax();
259 ++drv_data->tx;
262 /* poll for SPI completion before return */
263 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
264 cpu_relax();
267 static void u8_cs_chg_writer(struct driver_data *drv_data)
269 struct chip_data *chip = drv_data->cur_chip;
271 while (drv_data->tx < drv_data->tx_end) {
272 cs_active(drv_data, chip);
274 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
275 while (read_STAT(drv_data) & BIT_STAT_TXS)
276 cpu_relax();
277 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
278 cpu_relax();
280 cs_deactive(drv_data, chip);
282 ++drv_data->tx;
286 static void u8_reader(struct driver_data *drv_data)
288 dev_dbg(&drv_data->pdev->dev,
289 "cr-8 is 0x%x\n", read_STAT(drv_data));
291 /* poll for SPI completion before start */
292 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
293 cpu_relax();
295 /* clear TDBR buffer before read(else it will be shifted out) */
296 write_TDBR(drv_data, 0xFFFF);
298 dummy_read(drv_data);
300 while (drv_data->rx < drv_data->rx_end - 1) {
301 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
302 cpu_relax();
303 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
304 ++drv_data->rx;
307 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
308 cpu_relax();
309 *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
310 ++drv_data->rx;
313 static void u8_cs_chg_reader(struct driver_data *drv_data)
315 struct chip_data *chip = drv_data->cur_chip;
317 while (drv_data->rx < drv_data->rx_end) {
318 cs_active(drv_data, chip);
319 read_RDBR(drv_data); /* kick off */
321 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
322 cpu_relax();
323 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
324 cpu_relax();
326 *(u8 *) (drv_data->rx) = read_SHAW(drv_data);
327 cs_deactive(drv_data, chip);
329 ++drv_data->rx;
333 static void u8_duplex(struct driver_data *drv_data)
335 /* in duplex mode, clk is triggered by writing of TDBR */
336 while (drv_data->rx < drv_data->rx_end) {
337 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
338 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
339 cpu_relax();
340 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
341 cpu_relax();
342 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
343 ++drv_data->rx;
344 ++drv_data->tx;
348 static void u8_cs_chg_duplex(struct driver_data *drv_data)
350 struct chip_data *chip = drv_data->cur_chip;
352 while (drv_data->rx < drv_data->rx_end) {
353 cs_active(drv_data, chip);
355 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
357 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
358 cpu_relax();
359 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
360 cpu_relax();
361 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
363 cs_deactive(drv_data, chip);
365 ++drv_data->rx;
366 ++drv_data->tx;
370 static void u16_writer(struct driver_data *drv_data)
372 dev_dbg(&drv_data->pdev->dev,
373 "cr16 is 0x%x\n", read_STAT(drv_data));
375 while (drv_data->tx < drv_data->tx_end) {
376 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
377 while ((read_STAT(drv_data) & BIT_STAT_TXS))
378 cpu_relax();
379 drv_data->tx += 2;
382 /* poll for SPI completion before return */
383 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
384 cpu_relax();
387 static void u16_cs_chg_writer(struct driver_data *drv_data)
389 struct chip_data *chip = drv_data->cur_chip;
391 while (drv_data->tx < drv_data->tx_end) {
392 cs_active(drv_data, chip);
394 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
395 while ((read_STAT(drv_data) & BIT_STAT_TXS))
396 cpu_relax();
397 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
398 cpu_relax();
400 cs_deactive(drv_data, chip);
402 drv_data->tx += 2;
406 static void u16_reader(struct driver_data *drv_data)
408 dev_dbg(&drv_data->pdev->dev,
409 "cr-16 is 0x%x\n", read_STAT(drv_data));
411 /* poll for SPI completion before start */
412 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
413 cpu_relax();
415 /* clear TDBR buffer before read(else it will be shifted out) */
416 write_TDBR(drv_data, 0xFFFF);
418 dummy_read(drv_data);
420 while (drv_data->rx < (drv_data->rx_end - 2)) {
421 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
422 cpu_relax();
423 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
424 drv_data->rx += 2;
427 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
428 cpu_relax();
429 *(u16 *) (drv_data->rx) = read_SHAW(drv_data);
430 drv_data->rx += 2;
433 static void u16_cs_chg_reader(struct driver_data *drv_data)
435 struct chip_data *chip = drv_data->cur_chip;
437 /* poll for SPI completion before start */
438 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
439 cpu_relax();
441 /* clear TDBR buffer before read(else it will be shifted out) */
442 write_TDBR(drv_data, 0xFFFF);
444 cs_active(drv_data, chip);
445 dummy_read(drv_data);
447 while (drv_data->rx < drv_data->rx_end - 2) {
448 cs_deactive(drv_data, chip);
450 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
451 cpu_relax();
452 cs_active(drv_data, chip);
453 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
454 drv_data->rx += 2;
456 cs_deactive(drv_data, chip);
458 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
459 cpu_relax();
460 *(u16 *) (drv_data->rx) = read_SHAW(drv_data);
461 drv_data->rx += 2;
464 static void u16_duplex(struct driver_data *drv_data)
466 /* in duplex mode, clk is triggered by writing of TDBR */
467 while (drv_data->tx < drv_data->tx_end) {
468 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
469 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
470 cpu_relax();
471 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
472 cpu_relax();
473 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
474 drv_data->rx += 2;
475 drv_data->tx += 2;
479 static void u16_cs_chg_duplex(struct driver_data *drv_data)
481 struct chip_data *chip = drv_data->cur_chip;
483 while (drv_data->tx < drv_data->tx_end) {
484 cs_active(drv_data, chip);
486 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
487 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
488 cpu_relax();
489 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
490 cpu_relax();
491 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
493 cs_deactive(drv_data, chip);
495 drv_data->rx += 2;
496 drv_data->tx += 2;
500 /* test if ther is more transfer to be done */
501 static void *next_transfer(struct driver_data *drv_data)
503 struct spi_message *msg = drv_data->cur_msg;
504 struct spi_transfer *trans = drv_data->cur_transfer;
506 /* Move to next transfer */
507 if (trans->transfer_list.next != &msg->transfers) {
508 drv_data->cur_transfer =
509 list_entry(trans->transfer_list.next,
510 struct spi_transfer, transfer_list);
511 return RUNNING_STATE;
512 } else
513 return DONE_STATE;
517 * caller already set message->status;
518 * dma and pio irqs are blocked give finished message back
520 static void giveback(struct driver_data *drv_data)
522 struct chip_data *chip = drv_data->cur_chip;
523 struct spi_transfer *last_transfer;
524 unsigned long flags;
525 struct spi_message *msg;
527 spin_lock_irqsave(&drv_data->lock, flags);
528 msg = drv_data->cur_msg;
529 drv_data->cur_msg = NULL;
530 drv_data->cur_transfer = NULL;
531 drv_data->cur_chip = NULL;
532 queue_work(drv_data->workqueue, &drv_data->pump_messages);
533 spin_unlock_irqrestore(&drv_data->lock, flags);
535 last_transfer = list_entry(msg->transfers.prev,
536 struct spi_transfer, transfer_list);
538 msg->state = NULL;
540 /* disable chip select signal. And not stop spi in autobuffer mode */
541 if (drv_data->tx_dma != 0xFFFF) {
542 cs_deactive(drv_data, chip);
543 bfin_spi_disable(drv_data);
546 if (!drv_data->cs_change)
547 cs_deactive(drv_data, chip);
549 if (msg->complete)
550 msg->complete(msg->context);
553 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
555 struct driver_data *drv_data = dev_id;
556 struct chip_data *chip = drv_data->cur_chip;
557 struct spi_message *msg = drv_data->cur_msg;
559 dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");
560 clear_dma_irqstat(drv_data->dma_channel);
562 /* Wait for DMA to complete */
563 while (get_dma_curr_irqstat(drv_data->dma_channel) & DMA_RUN)
564 cpu_relax();
567 * wait for the last transaction shifted out. HRM states:
568 * at this point there may still be data in the SPI DMA FIFO waiting
569 * to be transmitted ... software needs to poll TXS in the SPI_STAT
570 * register until it goes low for 2 successive reads
572 if (drv_data->tx != NULL) {
573 while ((read_STAT(drv_data) & TXS) ||
574 (read_STAT(drv_data) & TXS))
575 cpu_relax();
578 while (!(read_STAT(drv_data) & SPIF))
579 cpu_relax();
581 msg->actual_length += drv_data->len_in_bytes;
583 if (drv_data->cs_change)
584 cs_deactive(drv_data, chip);
586 /* Move to next transfer */
587 msg->state = next_transfer(drv_data);
589 /* Schedule transfer tasklet */
590 tasklet_schedule(&drv_data->pump_transfers);
592 /* free the irq handler before next transfer */
593 dev_dbg(&drv_data->pdev->dev,
594 "disable dma channel irq%d\n",
595 drv_data->dma_channel);
596 dma_disable_irq(drv_data->dma_channel);
598 return IRQ_HANDLED;
601 static void pump_transfers(unsigned long data)
603 struct driver_data *drv_data = (struct driver_data *)data;
604 struct spi_message *message = NULL;
605 struct spi_transfer *transfer = NULL;
606 struct spi_transfer *previous = NULL;
607 struct chip_data *chip = NULL;
608 u8 width;
609 u16 cr, dma_width, dma_config;
610 u32 tranf_success = 1;
612 /* Get current state information */
613 message = drv_data->cur_msg;
614 transfer = drv_data->cur_transfer;
615 chip = drv_data->cur_chip;
618 * if msg is error or done, report it back using complete() callback
621 /* Handle for abort */
622 if (message->state == ERROR_STATE) {
623 message->status = -EIO;
624 giveback(drv_data);
625 return;
628 /* Handle end of message */
629 if (message->state == DONE_STATE) {
630 message->status = 0;
631 giveback(drv_data);
632 return;
635 /* Delay if requested at end of transfer */
636 if (message->state == RUNNING_STATE) {
637 previous = list_entry(transfer->transfer_list.prev,
638 struct spi_transfer, transfer_list);
639 if (previous->delay_usecs)
640 udelay(previous->delay_usecs);
643 /* Setup the transfer state based on the type of transfer */
644 if (flush(drv_data) == 0) {
645 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
646 message->status = -EIO;
647 giveback(drv_data);
648 return;
651 if (transfer->tx_buf != NULL) {
652 drv_data->tx = (void *)transfer->tx_buf;
653 drv_data->tx_end = drv_data->tx + transfer->len;
654 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
655 transfer->tx_buf, drv_data->tx_end);
656 } else {
657 drv_data->tx = NULL;
660 if (transfer->rx_buf != NULL) {
661 drv_data->rx = transfer->rx_buf;
662 drv_data->rx_end = drv_data->rx + transfer->len;
663 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
664 transfer->rx_buf, drv_data->rx_end);
665 } else {
666 drv_data->rx = NULL;
669 drv_data->rx_dma = transfer->rx_dma;
670 drv_data->tx_dma = transfer->tx_dma;
671 drv_data->len_in_bytes = transfer->len;
672 drv_data->cs_change = transfer->cs_change;
674 /* Bits per word setup */
675 switch (transfer->bits_per_word) {
676 case 8:
677 drv_data->n_bytes = 1;
678 width = CFG_SPI_WORDSIZE8;
679 drv_data->read = chip->cs_change_per_word ?
680 u8_cs_chg_reader : u8_reader;
681 drv_data->write = chip->cs_change_per_word ?
682 u8_cs_chg_writer : u8_writer;
683 drv_data->duplex = chip->cs_change_per_word ?
684 u8_cs_chg_duplex : u8_duplex;
685 break;
687 case 16:
688 drv_data->n_bytes = 2;
689 width = CFG_SPI_WORDSIZE16;
690 drv_data->read = chip->cs_change_per_word ?
691 u16_cs_chg_reader : u16_reader;
692 drv_data->write = chip->cs_change_per_word ?
693 u16_cs_chg_writer : u16_writer;
694 drv_data->duplex = chip->cs_change_per_word ?
695 u16_cs_chg_duplex : u16_duplex;
696 break;
698 default:
699 /* No change, the same as default setting */
700 drv_data->n_bytes = chip->n_bytes;
701 width = chip->width;
702 drv_data->write = drv_data->tx ? chip->write : null_writer;
703 drv_data->read = drv_data->rx ? chip->read : null_reader;
704 drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
705 break;
707 cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
708 cr |= (width << 8);
709 write_CTRL(drv_data, cr);
711 if (width == CFG_SPI_WORDSIZE16) {
712 drv_data->len = (transfer->len) >> 1;
713 } else {
714 drv_data->len = transfer->len;
716 dev_dbg(&drv_data->pdev->dev, "transfer: ",
717 "drv_data->write is %p, chip->write is %p, null_wr is %p\n",
718 drv_data->write, chip->write, null_writer);
720 /* speed and width has been set on per message */
721 message->state = RUNNING_STATE;
722 dma_config = 0;
724 /* Speed setup (surely valid because already checked) */
725 if (transfer->speed_hz)
726 write_BAUD(drv_data, hz_to_spi_baud(transfer->speed_hz));
727 else
728 write_BAUD(drv_data, chip->baud);
730 write_STAT(drv_data, BIT_STAT_CLR);
731 cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
732 cs_active(drv_data, chip);
734 dev_dbg(&drv_data->pdev->dev,
735 "now pumping a transfer: width is %d, len is %d\n",
736 width, transfer->len);
739 * Try to map dma buffer and do a dma transfer if
740 * successful use different way to r/w according to
741 * drv_data->cur_chip->enable_dma
743 if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
745 disable_dma(drv_data->dma_channel);
746 clear_dma_irqstat(drv_data->dma_channel);
747 bfin_spi_disable(drv_data);
749 /* config dma channel */
750 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
751 if (width == CFG_SPI_WORDSIZE16) {
752 set_dma_x_count(drv_data->dma_channel, drv_data->len);
753 set_dma_x_modify(drv_data->dma_channel, 2);
754 dma_width = WDSIZE_16;
755 } else {
756 set_dma_x_count(drv_data->dma_channel, drv_data->len);
757 set_dma_x_modify(drv_data->dma_channel, 1);
758 dma_width = WDSIZE_8;
761 /* poll for SPI completion before start */
762 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
763 cpu_relax();
765 /* dirty hack for autobuffer DMA mode */
766 if (drv_data->tx_dma == 0xFFFF) {
767 dev_dbg(&drv_data->pdev->dev,
768 "doing autobuffer DMA out.\n");
770 /* no irq in autobuffer mode */
771 dma_config =
772 (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
773 set_dma_config(drv_data->dma_channel, dma_config);
774 set_dma_start_addr(drv_data->dma_channel,
775 (unsigned long)drv_data->tx);
776 enable_dma(drv_data->dma_channel);
778 /* start SPI transfer */
779 write_CTRL(drv_data,
780 (cr | CFG_SPI_DMAWRITE | BIT_CTL_ENABLE));
782 /* just return here, there can only be one transfer
783 * in this mode
785 message->status = 0;
786 giveback(drv_data);
787 return;
790 /* In dma mode, rx or tx must be NULL in one transfer */
791 if (drv_data->rx != NULL) {
792 /* set transfer mode, and enable SPI */
793 dev_dbg(&drv_data->pdev->dev, "doing DMA in.\n");
795 /* clear tx reg soformer data is not shifted out */
796 write_TDBR(drv_data, 0xFFFF);
798 set_dma_x_count(drv_data->dma_channel, drv_data->len);
800 /* start dma */
801 dma_enable_irq(drv_data->dma_channel);
802 dma_config = (WNR | RESTART | dma_width | DI_EN);
803 set_dma_config(drv_data->dma_channel, dma_config);
804 set_dma_start_addr(drv_data->dma_channel,
805 (unsigned long)drv_data->rx);
806 enable_dma(drv_data->dma_channel);
808 /* start SPI transfer */
809 write_CTRL(drv_data,
810 (cr | CFG_SPI_DMAREAD | BIT_CTL_ENABLE));
812 } else if (drv_data->tx != NULL) {
813 dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
815 /* start dma */
816 dma_enable_irq(drv_data->dma_channel);
817 dma_config = (RESTART | dma_width | DI_EN);
818 set_dma_config(drv_data->dma_channel, dma_config);
819 set_dma_start_addr(drv_data->dma_channel,
820 (unsigned long)drv_data->tx);
821 enable_dma(drv_data->dma_channel);
823 /* start SPI transfer */
824 write_CTRL(drv_data,
825 (cr | CFG_SPI_DMAWRITE | BIT_CTL_ENABLE));
827 } else {
828 /* IO mode write then read */
829 dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
831 if (drv_data->tx != NULL && drv_data->rx != NULL) {
832 /* full duplex mode */
833 BUG_ON((drv_data->tx_end - drv_data->tx) !=
834 (drv_data->rx_end - drv_data->rx));
835 dev_dbg(&drv_data->pdev->dev,
836 "IO duplex: cr is 0x%x\n", cr);
838 /* set SPI transfer mode */
839 write_CTRL(drv_data, (cr | CFG_SPI_WRITE));
841 drv_data->duplex(drv_data);
843 if (drv_data->tx != drv_data->tx_end)
844 tranf_success = 0;
845 } else if (drv_data->tx != NULL) {
846 /* write only half duplex */
847 dev_dbg(&drv_data->pdev->dev,
848 "IO write: cr is 0x%x\n", cr);
850 /* set SPI transfer mode */
851 write_CTRL(drv_data, (cr | CFG_SPI_WRITE));
853 drv_data->write(drv_data);
855 if (drv_data->tx != drv_data->tx_end)
856 tranf_success = 0;
857 } else if (drv_data->rx != NULL) {
858 /* read only half duplex */
859 dev_dbg(&drv_data->pdev->dev,
860 "IO read: cr is 0x%x\n", cr);
862 /* set SPI transfer mode */
863 write_CTRL(drv_data, (cr | CFG_SPI_READ));
865 drv_data->read(drv_data);
866 if (drv_data->rx != drv_data->rx_end)
867 tranf_success = 0;
870 if (!tranf_success) {
871 dev_dbg(&drv_data->pdev->dev,
872 "IO write error!\n");
873 message->state = ERROR_STATE;
874 } else {
875 /* Update total byte transfered */
876 message->actual_length += drv_data->len;
878 /* Move to next transfer of this msg */
879 message->state = next_transfer(drv_data);
882 /* Schedule next transfer tasklet */
883 tasklet_schedule(&drv_data->pump_transfers);
888 /* pop a msg from queue and kick off real transfer */
889 static void pump_messages(struct work_struct *work)
891 struct driver_data *drv_data;
892 unsigned long flags;
894 drv_data = container_of(work, struct driver_data, pump_messages);
896 /* Lock queue and check for queue work */
897 spin_lock_irqsave(&drv_data->lock, flags);
898 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
899 /* pumper kicked off but no work to do */
900 drv_data->busy = 0;
901 spin_unlock_irqrestore(&drv_data->lock, flags);
902 return;
905 /* Make sure we are not already running a message */
906 if (drv_data->cur_msg) {
907 spin_unlock_irqrestore(&drv_data->lock, flags);
908 return;
911 /* Extract head of queue */
912 drv_data->cur_msg = list_entry(drv_data->queue.next,
913 struct spi_message, queue);
915 /* Setup the SSP using the per chip configuration */
916 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
917 restore_state(drv_data);
919 list_del_init(&drv_data->cur_msg->queue);
921 /* Initial message state */
922 drv_data->cur_msg->state = START_STATE;
923 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
924 struct spi_transfer, transfer_list);
926 dev_dbg(&drv_data->pdev->dev, "got a message to pump, "
927 "state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
928 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
929 drv_data->cur_chip->ctl_reg);
931 dev_dbg(&drv_data->pdev->dev,
932 "the first transfer len is %d\n",
933 drv_data->cur_transfer->len);
935 /* Mark as busy and launch transfers */
936 tasklet_schedule(&drv_data->pump_transfers);
938 drv_data->busy = 1;
939 spin_unlock_irqrestore(&drv_data->lock, flags);
943 * got a msg to transfer, queue it in drv_data->queue.
944 * And kick off message pumper
946 static int transfer(struct spi_device *spi, struct spi_message *msg)
948 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
949 unsigned long flags;
951 spin_lock_irqsave(&drv_data->lock, flags);
953 if (drv_data->run == QUEUE_STOPPED) {
954 spin_unlock_irqrestore(&drv_data->lock, flags);
955 return -ESHUTDOWN;
958 msg->actual_length = 0;
959 msg->status = -EINPROGRESS;
960 msg->state = START_STATE;
962 dev_dbg(&spi->dev, "adding an msg in transfer() \n");
963 list_add_tail(&msg->queue, &drv_data->queue);
965 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
966 queue_work(drv_data->workqueue, &drv_data->pump_messages);
968 spin_unlock_irqrestore(&drv_data->lock, flags);
970 return 0;
973 #define MAX_SPI_SSEL 7
975 static u16 ssel[3][MAX_SPI_SSEL] = {
976 {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
977 P_SPI0_SSEL4, P_SPI0_SSEL5,
978 P_SPI0_SSEL6, P_SPI0_SSEL7},
980 {P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
981 P_SPI1_SSEL4, P_SPI1_SSEL5,
982 P_SPI1_SSEL6, P_SPI1_SSEL7},
984 {P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
985 P_SPI2_SSEL4, P_SPI2_SSEL5,
986 P_SPI2_SSEL6, P_SPI2_SSEL7},
989 /* first setup for new devices */
990 static int setup(struct spi_device *spi)
992 struct bfin5xx_spi_chip *chip_info = NULL;
993 struct chip_data *chip;
994 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
995 u8 spi_flg;
997 /* Abort device setup if requested features are not supported */
998 if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
999 dev_err(&spi->dev, "requested mode not fully supported\n");
1000 return -EINVAL;
1003 /* Zero (the default) here means 8 bits */
1004 if (!spi->bits_per_word)
1005 spi->bits_per_word = 8;
1007 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
1008 return -EINVAL;
1010 /* Only alloc (or use chip_info) on first setup */
1011 chip = spi_get_ctldata(spi);
1012 if (chip == NULL) {
1013 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1014 if (!chip)
1015 return -ENOMEM;
1017 chip->enable_dma = 0;
1018 chip_info = spi->controller_data;
1021 /* chip_info isn't always needed */
1022 if (chip_info) {
1023 /* Make sure people stop trying to set fields via ctl_reg
1024 * when they should actually be using common SPI framework.
1025 * Currently we let through: WOM EMISO PSSE GM SZ TIMOD.
1026 * Not sure if a user actually needs/uses any of these,
1027 * but let's assume (for now) they do.
1029 if (chip_info->ctl_reg & (SPE|MSTR|CPOL|CPHA|LSBF|SIZE)) {
1030 dev_err(&spi->dev, "do not set bits in ctl_reg "
1031 "that the SPI framework manages\n");
1032 return -EINVAL;
1035 chip->enable_dma = chip_info->enable_dma != 0
1036 && drv_data->master_info->enable_dma;
1037 chip->ctl_reg = chip_info->ctl_reg;
1038 chip->bits_per_word = chip_info->bits_per_word;
1039 chip->cs_change_per_word = chip_info->cs_change_per_word;
1040 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
1043 /* translate common spi framework into our register */
1044 if (spi->mode & SPI_CPOL)
1045 chip->ctl_reg |= CPOL;
1046 if (spi->mode & SPI_CPHA)
1047 chip->ctl_reg |= CPHA;
1048 if (spi->mode & SPI_LSB_FIRST)
1049 chip->ctl_reg |= LSBF;
1050 /* we dont support running in slave mode (yet?) */
1051 chip->ctl_reg |= MSTR;
1054 * if any one SPI chip is registered and wants DMA, request the
1055 * DMA channel for it
1057 if (chip->enable_dma && !drv_data->dma_requested) {
1058 /* register dma irq handler */
1059 if (request_dma(drv_data->dma_channel, "BF53x_SPI_DMA") < 0) {
1060 dev_dbg(&spi->dev,
1061 "Unable to request BlackFin SPI DMA channel\n");
1062 return -ENODEV;
1064 if (set_dma_callback(drv_data->dma_channel,
1065 (void *)dma_irq_handler, drv_data) < 0) {
1066 dev_dbg(&spi->dev, "Unable to set dma callback\n");
1067 return -EPERM;
1069 dma_disable_irq(drv_data->dma_channel);
1070 drv_data->dma_requested = 1;
1074 * Notice: for blackfin, the speed_hz is the value of register
1075 * SPI_BAUD, not the real baudrate
1077 chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1078 spi_flg = ~(1 << (spi->chip_select));
1079 chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
1080 chip->chip_select_num = spi->chip_select;
1082 switch (chip->bits_per_word) {
1083 case 8:
1084 chip->n_bytes = 1;
1085 chip->width = CFG_SPI_WORDSIZE8;
1086 chip->read = chip->cs_change_per_word ?
1087 u8_cs_chg_reader : u8_reader;
1088 chip->write = chip->cs_change_per_word ?
1089 u8_cs_chg_writer : u8_writer;
1090 chip->duplex = chip->cs_change_per_word ?
1091 u8_cs_chg_duplex : u8_duplex;
1092 break;
1094 case 16:
1095 chip->n_bytes = 2;
1096 chip->width = CFG_SPI_WORDSIZE16;
1097 chip->read = chip->cs_change_per_word ?
1098 u16_cs_chg_reader : u16_reader;
1099 chip->write = chip->cs_change_per_word ?
1100 u16_cs_chg_writer : u16_writer;
1101 chip->duplex = chip->cs_change_per_word ?
1102 u16_cs_chg_duplex : u16_duplex;
1103 break;
1105 default:
1106 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1107 chip->bits_per_word);
1108 kfree(chip);
1109 return -ENODEV;
1112 dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1113 spi->modalias, chip->width, chip->enable_dma);
1114 dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1115 chip->ctl_reg, chip->flag);
1117 spi_set_ctldata(spi, chip);
1119 dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
1120 if ((chip->chip_select_num > 0)
1121 && (chip->chip_select_num <= spi->master->num_chipselect))
1122 peripheral_request(ssel[spi->master->bus_num]
1123 [chip->chip_select_num-1], spi->modalias);
1125 cs_deactive(drv_data, chip);
1127 return 0;
1131 * callback for spi framework.
1132 * clean driver specific data
1134 static void cleanup(struct spi_device *spi)
1136 struct chip_data *chip = spi_get_ctldata(spi);
1138 if ((chip->chip_select_num > 0)
1139 && (chip->chip_select_num <= spi->master->num_chipselect))
1140 peripheral_free(ssel[spi->master->bus_num]
1141 [chip->chip_select_num-1]);
1143 kfree(chip);
1146 static inline int init_queue(struct driver_data *drv_data)
1148 INIT_LIST_HEAD(&drv_data->queue);
1149 spin_lock_init(&drv_data->lock);
1151 drv_data->run = QUEUE_STOPPED;
1152 drv_data->busy = 0;
1154 /* init transfer tasklet */
1155 tasklet_init(&drv_data->pump_transfers,
1156 pump_transfers, (unsigned long)drv_data);
1158 /* init messages workqueue */
1159 INIT_WORK(&drv_data->pump_messages, pump_messages);
1160 drv_data->workqueue =
1161 create_singlethread_workqueue(drv_data->master->dev.parent->bus_id);
1162 if (drv_data->workqueue == NULL)
1163 return -EBUSY;
1165 return 0;
1168 static inline int start_queue(struct driver_data *drv_data)
1170 unsigned long flags;
1172 spin_lock_irqsave(&drv_data->lock, flags);
1174 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1175 spin_unlock_irqrestore(&drv_data->lock, flags);
1176 return -EBUSY;
1179 drv_data->run = QUEUE_RUNNING;
1180 drv_data->cur_msg = NULL;
1181 drv_data->cur_transfer = NULL;
1182 drv_data->cur_chip = NULL;
1183 spin_unlock_irqrestore(&drv_data->lock, flags);
1185 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1187 return 0;
1190 static inline int stop_queue(struct driver_data *drv_data)
1192 unsigned long flags;
1193 unsigned limit = 500;
1194 int status = 0;
1196 spin_lock_irqsave(&drv_data->lock, flags);
1199 * This is a bit lame, but is optimized for the common execution path.
1200 * A wait_queue on the drv_data->busy could be used, but then the common
1201 * execution path (pump_messages) would be required to call wake_up or
1202 * friends on every SPI message. Do this instead
1204 drv_data->run = QUEUE_STOPPED;
1205 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1206 spin_unlock_irqrestore(&drv_data->lock, flags);
1207 msleep(10);
1208 spin_lock_irqsave(&drv_data->lock, flags);
1211 if (!list_empty(&drv_data->queue) || drv_data->busy)
1212 status = -EBUSY;
1214 spin_unlock_irqrestore(&drv_data->lock, flags);
1216 return status;
1219 static inline int destroy_queue(struct driver_data *drv_data)
1221 int status;
1223 status = stop_queue(drv_data);
1224 if (status != 0)
1225 return status;
1227 destroy_workqueue(drv_data->workqueue);
1229 return 0;
1232 static int __init bfin5xx_spi_probe(struct platform_device *pdev)
1234 struct device *dev = &pdev->dev;
1235 struct bfin5xx_spi_master *platform_info;
1236 struct spi_master *master;
1237 struct driver_data *drv_data = 0;
1238 struct resource *res;
1239 int status = 0;
1241 platform_info = dev->platform_data;
1243 /* Allocate master with space for drv_data */
1244 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1245 if (!master) {
1246 dev_err(&pdev->dev, "can not alloc spi_master\n");
1247 return -ENOMEM;
1250 drv_data = spi_master_get_devdata(master);
1251 drv_data->master = master;
1252 drv_data->master_info = platform_info;
1253 drv_data->pdev = pdev;
1254 drv_data->pin_req = platform_info->pin_req;
1256 master->bus_num = pdev->id;
1257 master->num_chipselect = platform_info->num_chipselect;
1258 master->cleanup = cleanup;
1259 master->setup = setup;
1260 master->transfer = transfer;
1262 /* Find and map our resources */
1263 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1264 if (res == NULL) {
1265 dev_err(dev, "Cannot get IORESOURCE_MEM\n");
1266 status = -ENOENT;
1267 goto out_error_get_res;
1270 drv_data->regs_base = ioremap(res->start, (res->end - res->start + 1));
1271 if (drv_data->regs_base == NULL) {
1272 dev_err(dev, "Cannot map IO\n");
1273 status = -ENXIO;
1274 goto out_error_ioremap;
1277 drv_data->dma_channel = platform_get_irq(pdev, 0);
1278 if (drv_data->dma_channel < 0) {
1279 dev_err(dev, "No DMA channel specified\n");
1280 status = -ENOENT;
1281 goto out_error_no_dma_ch;
1284 /* Initial and start queue */
1285 status = init_queue(drv_data);
1286 if (status != 0) {
1287 dev_err(dev, "problem initializing queue\n");
1288 goto out_error_queue_alloc;
1291 status = start_queue(drv_data);
1292 if (status != 0) {
1293 dev_err(dev, "problem starting queue\n");
1294 goto out_error_queue_alloc;
1297 /* Register with the SPI framework */
1298 platform_set_drvdata(pdev, drv_data);
1299 status = spi_register_master(master);
1300 if (status != 0) {
1301 dev_err(dev, "problem registering spi master\n");
1302 goto out_error_queue_alloc;
1305 status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
1306 if (status != 0) {
1307 dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
1308 goto out_error;
1311 dev_info(dev, "%s, Version %s, regs_base@%p, dma channel@%d\n",
1312 DRV_DESC, DRV_VERSION, drv_data->regs_base,
1313 drv_data->dma_channel);
1314 return status;
1316 out_error_queue_alloc:
1317 destroy_queue(drv_data);
1318 out_error_no_dma_ch:
1319 iounmap((void *) drv_data->regs_base);
1320 out_error_ioremap:
1321 out_error_get_res:
1322 out_error:
1323 spi_master_put(master);
1325 return status;
1328 /* stop hardware and remove the driver */
1329 static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
1331 struct driver_data *drv_data = platform_get_drvdata(pdev);
1332 int status = 0;
1334 if (!drv_data)
1335 return 0;
1337 /* Remove the queue */
1338 status = destroy_queue(drv_data);
1339 if (status != 0)
1340 return status;
1342 /* Disable the SSP at the peripheral and SOC level */
1343 bfin_spi_disable(drv_data);
1345 /* Release DMA */
1346 if (drv_data->master_info->enable_dma) {
1347 if (dma_channel_active(drv_data->dma_channel))
1348 free_dma(drv_data->dma_channel);
1351 /* Disconnect from the SPI framework */
1352 spi_unregister_master(drv_data->master);
1354 peripheral_free_list(drv_data->pin_req);
1356 /* Prevent double remove */
1357 platform_set_drvdata(pdev, NULL);
1359 return 0;
1362 #ifdef CONFIG_PM
1363 static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1365 struct driver_data *drv_data = platform_get_drvdata(pdev);
1366 int status = 0;
1368 status = stop_queue(drv_data);
1369 if (status != 0)
1370 return status;
1372 /* stop hardware */
1373 bfin_spi_disable(drv_data);
1375 return 0;
1378 static int bfin5xx_spi_resume(struct platform_device *pdev)
1380 struct driver_data *drv_data = platform_get_drvdata(pdev);
1381 int status = 0;
1383 /* Enable the SPI interface */
1384 bfin_spi_enable(drv_data);
1386 /* Start the queue running */
1387 status = start_queue(drv_data);
1388 if (status != 0) {
1389 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1390 return status;
1393 return 0;
1395 #else
1396 #define bfin5xx_spi_suspend NULL
1397 #define bfin5xx_spi_resume NULL
1398 #endif /* CONFIG_PM */
1400 MODULE_ALIAS("bfin-spi-master"); /* for platform bus hotplug */
1401 static struct platform_driver bfin5xx_spi_driver = {
1402 .driver = {
1403 .name = DRV_NAME,
1404 .owner = THIS_MODULE,
1406 .suspend = bfin5xx_spi_suspend,
1407 .resume = bfin5xx_spi_resume,
1408 .remove = __devexit_p(bfin5xx_spi_remove),
1411 static int __init bfin5xx_spi_init(void)
1413 return platform_driver_probe(&bfin5xx_spi_driver, bfin5xx_spi_probe);
1415 module_init(bfin5xx_spi_init);
1417 static void __exit bfin5xx_spi_exit(void)
1419 platform_driver_unregister(&bfin5xx_spi_driver);
1421 module_exit(bfin5xx_spi_exit);