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.
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/delay.h>
14 #include <linux/device.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>
26 #include <asm/portmux.h>
27 #include <asm/bfin5xx_spi.h>
28 #include <asm/cacheflush.h>
30 #define DRV_NAME "bfin-spi"
31 #define DRV_AUTHOR "Bryan Wu, Luke Yang"
32 #define DRV_DESC "Blackfin BF5xx on-chip SPI Controller Driver"
33 #define DRV_VERSION "1.0"
35 MODULE_AUTHOR(DRV_AUTHOR
);
36 MODULE_DESCRIPTION(DRV_DESC
);
37 MODULE_LICENSE("GPL");
39 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07) == 0)
41 #define START_STATE ((void *)0)
42 #define RUNNING_STATE ((void *)1)
43 #define DONE_STATE ((void *)2)
44 #define ERROR_STATE ((void *)-1)
45 #define QUEUE_RUNNING 0
46 #define QUEUE_STOPPED 1
49 /* Driver model hookup */
50 struct platform_device
*pdev
;
52 /* SPI framework hookup */
53 struct spi_master
*master
;
55 /* Regs base of SPI controller */
56 void __iomem
*regs_base
;
58 /* Pin request list */
62 struct bfin5xx_spi_master
*master_info
;
64 /* Driver message queue */
65 struct workqueue_struct
*workqueue
;
66 struct work_struct pump_messages
;
68 struct list_head queue
;
72 /* Message Transfer pump */
73 struct tasklet_struct pump_transfers
;
75 /* Current message transfer state info */
76 struct spi_message
*cur_msg
;
77 struct spi_transfer
*cur_transfer
;
78 struct chip_data
*cur_chip
;
97 void (*write
) (struct driver_data
*);
98 void (*read
) (struct driver_data
*);
99 void (*duplex
) (struct driver_data
*);
109 u8 width
; /* 0 or 1 */
111 u8 bits_per_word
; /* 8 or 16 */
112 u8 cs_change_per_word
;
113 u16 cs_chg_udelay
; /* Some devices require > 255usec delay */
114 void (*write
) (struct driver_data
*);
115 void (*read
) (struct driver_data
*);
116 void (*duplex
) (struct driver_data
*);
119 #define DEFINE_SPI_REG(reg, off) \
120 static inline u16 read_##reg(struct driver_data *drv_data) \
121 { return bfin_read16(drv_data->regs_base + off); } \
122 static inline void write_##reg(struct driver_data *drv_data, u16 v) \
123 { bfin_write16(drv_data->regs_base + off, v); }
125 DEFINE_SPI_REG(CTRL
, 0x00)
126 DEFINE_SPI_REG(FLAG
, 0x04)
127 DEFINE_SPI_REG(STAT
, 0x08)
128 DEFINE_SPI_REG(TDBR
, 0x0C)
129 DEFINE_SPI_REG(RDBR
, 0x10)
130 DEFINE_SPI_REG(BAUD
, 0x14)
131 DEFINE_SPI_REG(SHAW
, 0x18)
133 static void bfin_spi_enable(struct driver_data
*drv_data
)
137 cr
= read_CTRL(drv_data
);
138 write_CTRL(drv_data
, (cr
| BIT_CTL_ENABLE
));
141 static void bfin_spi_disable(struct driver_data
*drv_data
)
145 cr
= read_CTRL(drv_data
);
146 write_CTRL(drv_data
, (cr
& (~BIT_CTL_ENABLE
)));
149 /* Caculate the SPI_BAUD register value based on input HZ */
150 static u16
hz_to_spi_baud(u32 speed_hz
)
152 u_long sclk
= get_sclk();
153 u16 spi_baud
= (sclk
/ (2 * speed_hz
));
155 if ((sclk
% (2 * speed_hz
)) > 0)
158 if (spi_baud
< MIN_SPI_BAUD_VAL
)
159 spi_baud
= MIN_SPI_BAUD_VAL
;
164 static int flush(struct driver_data
*drv_data
)
166 unsigned long limit
= loops_per_jiffy
<< 1;
168 /* wait for stop and clear stat */
169 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
) && limit
--)
172 write_STAT(drv_data
, BIT_STAT_CLR
);
177 /* Chip select operation functions for cs_change flag */
178 static void cs_active(struct driver_data
*drv_data
, struct chip_data
*chip
)
180 u16 flag
= read_FLAG(drv_data
);
183 flag
&= ~(chip
->flag
<< 8);
185 write_FLAG(drv_data
, flag
);
188 static void cs_deactive(struct driver_data
*drv_data
, struct chip_data
*chip
)
190 u16 flag
= read_FLAG(drv_data
);
192 flag
|= (chip
->flag
<< 8);
194 write_FLAG(drv_data
, flag
);
196 /* Move delay here for consistency */
197 if (chip
->cs_chg_udelay
)
198 udelay(chip
->cs_chg_udelay
);
201 /* stop controller and re-config current chip*/
202 static void restore_state(struct driver_data
*drv_data
)
204 struct chip_data
*chip
= drv_data
->cur_chip
;
206 /* Clear status and disable clock */
207 write_STAT(drv_data
, BIT_STAT_CLR
);
208 bfin_spi_disable(drv_data
);
209 dev_dbg(&drv_data
->pdev
->dev
, "restoring spi ctl state\n");
211 /* Load the registers */
212 write_CTRL(drv_data
, chip
->ctl_reg
);
213 write_BAUD(drv_data
, chip
->baud
);
215 bfin_spi_enable(drv_data
);
216 cs_active(drv_data
, chip
);
219 /* used to kick off transfer in rx mode */
220 static unsigned short dummy_read(struct driver_data
*drv_data
)
223 tmp
= read_RDBR(drv_data
);
227 static void null_writer(struct driver_data
*drv_data
)
229 u8 n_bytes
= drv_data
->n_bytes
;
231 while (drv_data
->tx
< drv_data
->tx_end
) {
232 write_TDBR(drv_data
, 0);
233 while ((read_STAT(drv_data
) & BIT_STAT_TXS
))
235 drv_data
->tx
+= n_bytes
;
239 static void null_reader(struct driver_data
*drv_data
)
241 u8 n_bytes
= drv_data
->n_bytes
;
242 dummy_read(drv_data
);
244 while (drv_data
->rx
< drv_data
->rx_end
) {
245 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
247 dummy_read(drv_data
);
248 drv_data
->rx
+= n_bytes
;
252 static void u8_writer(struct driver_data
*drv_data
)
254 dev_dbg(&drv_data
->pdev
->dev
,
255 "cr8-s is 0x%x\n", read_STAT(drv_data
));
257 while (drv_data
->tx
< drv_data
->tx_end
) {
258 write_TDBR(drv_data
, (*(u8
*) (drv_data
->tx
)));
259 while (read_STAT(drv_data
) & BIT_STAT_TXS
)
264 /* poll for SPI completion before return */
265 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
269 static void u8_cs_chg_writer(struct driver_data
*drv_data
)
271 struct chip_data
*chip
= drv_data
->cur_chip
;
273 while (drv_data
->tx
< drv_data
->tx_end
) {
274 cs_active(drv_data
, chip
);
276 write_TDBR(drv_data
, (*(u8
*) (drv_data
->tx
)));
277 while (read_STAT(drv_data
) & BIT_STAT_TXS
)
279 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
282 cs_deactive(drv_data
, chip
);
288 static void u8_reader(struct driver_data
*drv_data
)
290 dev_dbg(&drv_data
->pdev
->dev
,
291 "cr-8 is 0x%x\n", read_STAT(drv_data
));
293 /* poll for SPI completion before start */
294 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
297 /* clear TDBR buffer before read(else it will be shifted out) */
298 write_TDBR(drv_data
, 0xFFFF);
300 dummy_read(drv_data
);
302 while (drv_data
->rx
< drv_data
->rx_end
- 1) {
303 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
305 *(u8
*) (drv_data
->rx
) = read_RDBR(drv_data
);
309 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
311 *(u8
*) (drv_data
->rx
) = read_SHAW(drv_data
);
315 static void u8_cs_chg_reader(struct driver_data
*drv_data
)
317 struct chip_data
*chip
= drv_data
->cur_chip
;
319 while (drv_data
->rx
< drv_data
->rx_end
) {
320 cs_active(drv_data
, chip
);
321 read_RDBR(drv_data
); /* kick off */
323 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
325 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
328 *(u8
*) (drv_data
->rx
) = read_SHAW(drv_data
);
329 cs_deactive(drv_data
, chip
);
335 static void u8_duplex(struct driver_data
*drv_data
)
337 /* in duplex mode, clk is triggered by writing of TDBR */
338 while (drv_data
->rx
< drv_data
->rx_end
) {
339 write_TDBR(drv_data
, (*(u8
*) (drv_data
->tx
)));
340 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
342 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
344 *(u8
*) (drv_data
->rx
) = read_RDBR(drv_data
);
350 static void u8_cs_chg_duplex(struct driver_data
*drv_data
)
352 struct chip_data
*chip
= drv_data
->cur_chip
;
354 while (drv_data
->rx
< drv_data
->rx_end
) {
355 cs_active(drv_data
, chip
);
357 write_TDBR(drv_data
, (*(u8
*) (drv_data
->tx
)));
359 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
361 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
363 *(u8
*) (drv_data
->rx
) = read_RDBR(drv_data
);
365 cs_deactive(drv_data
, chip
);
372 static void u16_writer(struct driver_data
*drv_data
)
374 dev_dbg(&drv_data
->pdev
->dev
,
375 "cr16 is 0x%x\n", read_STAT(drv_data
));
377 while (drv_data
->tx
< drv_data
->tx_end
) {
378 write_TDBR(drv_data
, (*(u16
*) (drv_data
->tx
)));
379 while ((read_STAT(drv_data
) & BIT_STAT_TXS
))
384 /* poll for SPI completion before return */
385 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
389 static void u16_cs_chg_writer(struct driver_data
*drv_data
)
391 struct chip_data
*chip
= drv_data
->cur_chip
;
393 while (drv_data
->tx
< drv_data
->tx_end
) {
394 cs_active(drv_data
, chip
);
396 write_TDBR(drv_data
, (*(u16
*) (drv_data
->tx
)));
397 while ((read_STAT(drv_data
) & BIT_STAT_TXS
))
399 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
402 cs_deactive(drv_data
, chip
);
408 static void u16_reader(struct driver_data
*drv_data
)
410 dev_dbg(&drv_data
->pdev
->dev
,
411 "cr-16 is 0x%x\n", read_STAT(drv_data
));
413 /* poll for SPI completion before start */
414 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
417 /* clear TDBR buffer before read(else it will be shifted out) */
418 write_TDBR(drv_data
, 0xFFFF);
420 dummy_read(drv_data
);
422 while (drv_data
->rx
< (drv_data
->rx_end
- 2)) {
423 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
425 *(u16
*) (drv_data
->rx
) = read_RDBR(drv_data
);
429 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
431 *(u16
*) (drv_data
->rx
) = read_SHAW(drv_data
);
435 static void u16_cs_chg_reader(struct driver_data
*drv_data
)
437 struct chip_data
*chip
= drv_data
->cur_chip
;
439 /* poll for SPI completion before start */
440 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
443 /* clear TDBR buffer before read(else it will be shifted out) */
444 write_TDBR(drv_data
, 0xFFFF);
446 cs_active(drv_data
, chip
);
447 dummy_read(drv_data
);
449 while (drv_data
->rx
< drv_data
->rx_end
- 2) {
450 cs_deactive(drv_data
, chip
);
452 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
454 cs_active(drv_data
, chip
);
455 *(u16
*) (drv_data
->rx
) = read_RDBR(drv_data
);
458 cs_deactive(drv_data
, chip
);
460 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
462 *(u16
*) (drv_data
->rx
) = read_SHAW(drv_data
);
466 static void u16_duplex(struct driver_data
*drv_data
)
468 /* in duplex mode, clk is triggered by writing of TDBR */
469 while (drv_data
->tx
< drv_data
->tx_end
) {
470 write_TDBR(drv_data
, (*(u16
*) (drv_data
->tx
)));
471 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
473 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
475 *(u16
*) (drv_data
->rx
) = read_RDBR(drv_data
);
481 static void u16_cs_chg_duplex(struct driver_data
*drv_data
)
483 struct chip_data
*chip
= drv_data
->cur_chip
;
485 while (drv_data
->tx
< drv_data
->tx_end
) {
486 cs_active(drv_data
, chip
);
488 write_TDBR(drv_data
, (*(u16
*) (drv_data
->tx
)));
489 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
491 while (!(read_STAT(drv_data
) & BIT_STAT_RXS
))
493 *(u16
*) (drv_data
->rx
) = read_RDBR(drv_data
);
495 cs_deactive(drv_data
, chip
);
502 /* test if ther is more transfer to be done */
503 static void *next_transfer(struct driver_data
*drv_data
)
505 struct spi_message
*msg
= drv_data
->cur_msg
;
506 struct spi_transfer
*trans
= drv_data
->cur_transfer
;
508 /* Move to next transfer */
509 if (trans
->transfer_list
.next
!= &msg
->transfers
) {
510 drv_data
->cur_transfer
=
511 list_entry(trans
->transfer_list
.next
,
512 struct spi_transfer
, transfer_list
);
513 return RUNNING_STATE
;
519 * caller already set message->status;
520 * dma and pio irqs are blocked give finished message back
522 static void giveback(struct driver_data
*drv_data
)
524 struct chip_data
*chip
= drv_data
->cur_chip
;
525 struct spi_transfer
*last_transfer
;
527 struct spi_message
*msg
;
529 spin_lock_irqsave(&drv_data
->lock
, flags
);
530 msg
= drv_data
->cur_msg
;
531 drv_data
->cur_msg
= NULL
;
532 drv_data
->cur_transfer
= NULL
;
533 drv_data
->cur_chip
= NULL
;
534 queue_work(drv_data
->workqueue
, &drv_data
->pump_messages
);
535 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
537 last_transfer
= list_entry(msg
->transfers
.prev
,
538 struct spi_transfer
, transfer_list
);
542 /* disable chip select signal. And not stop spi in autobuffer mode */
543 if (drv_data
->tx_dma
!= 0xFFFF) {
544 cs_deactive(drv_data
, chip
);
545 bfin_spi_disable(drv_data
);
548 if (!drv_data
->cs_change
)
549 cs_deactive(drv_data
, chip
);
552 msg
->complete(msg
->context
);
555 static irqreturn_t
dma_irq_handler(int irq
, void *dev_id
)
557 struct driver_data
*drv_data
= dev_id
;
558 struct chip_data
*chip
= drv_data
->cur_chip
;
559 struct spi_message
*msg
= drv_data
->cur_msg
;
560 unsigned short dmastat
= get_dma_curr_irqstat(drv_data
->dma_channel
);
561 u16 spistat
= read_STAT(drv_data
);
563 dev_dbg(&drv_data
->pdev
->dev
,
564 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
567 clear_dma_irqstat(drv_data
->dma_channel
);
569 /* Wait for DMA to complete */
570 while (get_dma_curr_irqstat(drv_data
->dma_channel
) & DMA_RUN
)
574 * wait for the last transaction shifted out. HRM states:
575 * at this point there may still be data in the SPI DMA FIFO waiting
576 * to be transmitted ... software needs to poll TXS in the SPI_STAT
577 * register until it goes low for 2 successive reads
579 if (drv_data
->tx
!= NULL
) {
580 while ((read_STAT(drv_data
) & TXS
) ||
581 (read_STAT(drv_data
) & TXS
))
585 while (!(read_STAT(drv_data
) & SPIF
))
588 if ((dmastat
& DMA_ERR
) && (spistat
& RBSY
)) {
589 msg
->state
= ERROR_STATE
;
590 dev_err(&drv_data
->pdev
->dev
, "dma receive: fifo/buffer overflow\n");
592 msg
->actual_length
+= drv_data
->len_in_bytes
;
594 if (drv_data
->cs_change
)
595 cs_deactive(drv_data
, chip
);
597 /* Move to next transfer */
598 msg
->state
= next_transfer(drv_data
);
601 /* Schedule transfer tasklet */
602 tasklet_schedule(&drv_data
->pump_transfers
);
604 /* free the irq handler before next transfer */
605 dev_dbg(&drv_data
->pdev
->dev
,
606 "disable dma channel irq%d\n",
607 drv_data
->dma_channel
);
608 dma_disable_irq(drv_data
->dma_channel
);
613 static void pump_transfers(unsigned long data
)
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
;
621 u16 cr
, dma_width
, dma_config
;
622 u32 tranf_success
= 1;
625 /* Get current state information */
626 message
= drv_data
->cur_msg
;
627 transfer
= drv_data
->cur_transfer
;
628 chip
= drv_data
->cur_chip
;
631 * if msg is error or done, report it back using complete() callback
634 /* Handle for abort */
635 if (message
->state
== ERROR_STATE
) {
636 dev_dbg(&drv_data
->pdev
->dev
, "transfer: we've hit an error\n");
637 message
->status
= -EIO
;
642 /* Handle end of message */
643 if (message
->state
== DONE_STATE
) {
644 dev_dbg(&drv_data
->pdev
->dev
, "transfer: all done!\n");
650 /* Delay if requested at end of transfer */
651 if (message
->state
== RUNNING_STATE
) {
652 dev_dbg(&drv_data
->pdev
->dev
, "transfer: still running ...\n");
653 previous
= list_entry(transfer
->transfer_list
.prev
,
654 struct spi_transfer
, transfer_list
);
655 if (previous
->delay_usecs
)
656 udelay(previous
->delay_usecs
);
659 /* Setup the transfer state based on the type of transfer */
660 if (flush(drv_data
) == 0) {
661 dev_err(&drv_data
->pdev
->dev
, "pump_transfers: flush failed\n");
662 message
->status
= -EIO
;
667 if (transfer
->tx_buf
!= NULL
) {
668 drv_data
->tx
= (void *)transfer
->tx_buf
;
669 drv_data
->tx_end
= drv_data
->tx
+ transfer
->len
;
670 dev_dbg(&drv_data
->pdev
->dev
, "tx_buf is %p, tx_end is %p\n",
671 transfer
->tx_buf
, drv_data
->tx_end
);
676 if (transfer
->rx_buf
!= NULL
) {
677 full_duplex
= transfer
->tx_buf
!= NULL
;
678 drv_data
->rx
= transfer
->rx_buf
;
679 drv_data
->rx_end
= drv_data
->rx
+ transfer
->len
;
680 dev_dbg(&drv_data
->pdev
->dev
, "rx_buf is %p, rx_end is %p\n",
681 transfer
->rx_buf
, drv_data
->rx_end
);
686 drv_data
->rx_dma
= transfer
->rx_dma
;
687 drv_data
->tx_dma
= transfer
->tx_dma
;
688 drv_data
->len_in_bytes
= transfer
->len
;
689 drv_data
->cs_change
= transfer
->cs_change
;
691 /* Bits per word setup */
692 switch (transfer
->bits_per_word
) {
694 drv_data
->n_bytes
= 1;
695 width
= CFG_SPI_WORDSIZE8
;
696 drv_data
->read
= chip
->cs_change_per_word
?
697 u8_cs_chg_reader
: u8_reader
;
698 drv_data
->write
= chip
->cs_change_per_word
?
699 u8_cs_chg_writer
: u8_writer
;
700 drv_data
->duplex
= chip
->cs_change_per_word
?
701 u8_cs_chg_duplex
: u8_duplex
;
705 drv_data
->n_bytes
= 2;
706 width
= CFG_SPI_WORDSIZE16
;
707 drv_data
->read
= chip
->cs_change_per_word
?
708 u16_cs_chg_reader
: u16_reader
;
709 drv_data
->write
= chip
->cs_change_per_word
?
710 u16_cs_chg_writer
: u16_writer
;
711 drv_data
->duplex
= chip
->cs_change_per_word
?
712 u16_cs_chg_duplex
: u16_duplex
;
716 /* No change, the same as default setting */
717 drv_data
->n_bytes
= chip
->n_bytes
;
719 drv_data
->write
= drv_data
->tx
? chip
->write
: null_writer
;
720 drv_data
->read
= drv_data
->rx
? chip
->read
: null_reader
;
721 drv_data
->duplex
= chip
->duplex
? chip
->duplex
: null_writer
;
724 cr
= (read_CTRL(drv_data
) & (~BIT_CTL_TIMOD
));
726 write_CTRL(drv_data
, cr
);
728 if (width
== CFG_SPI_WORDSIZE16
) {
729 drv_data
->len
= (transfer
->len
) >> 1;
731 drv_data
->len
= transfer
->len
;
733 dev_dbg(&drv_data
->pdev
->dev
,
734 "transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
735 drv_data
->write
, chip
->write
, null_writer
);
737 /* speed and width has been set on per message */
738 message
->state
= RUNNING_STATE
;
741 /* Speed setup (surely valid because already checked) */
742 if (transfer
->speed_hz
)
743 write_BAUD(drv_data
, hz_to_spi_baud(transfer
->speed_hz
));
745 write_BAUD(drv_data
, chip
->baud
);
747 write_STAT(drv_data
, BIT_STAT_CLR
);
748 cr
= (read_CTRL(drv_data
) & (~BIT_CTL_TIMOD
));
749 cs_active(drv_data
, chip
);
751 dev_dbg(&drv_data
->pdev
->dev
,
752 "now pumping a transfer: width is %d, len is %d\n",
753 width
, transfer
->len
);
756 * Try to map dma buffer and do a dma transfer. If successful use,
757 * different way to r/w according to the enable_dma settings and if
758 * we are not doing a full duplex transfer (since the hardware does
759 * not support full duplex DMA transfers).
761 if (!full_duplex
&& drv_data
->cur_chip
->enable_dma
762 && drv_data
->len
> 6) {
764 unsigned long dma_start_addr
, flags
;
766 disable_dma(drv_data
->dma_channel
);
767 clear_dma_irqstat(drv_data
->dma_channel
);
769 /* config dma channel */
770 dev_dbg(&drv_data
->pdev
->dev
, "doing dma transfer\n");
771 set_dma_x_count(drv_data
->dma_channel
, drv_data
->len
);
772 if (width
== CFG_SPI_WORDSIZE16
) {
773 set_dma_x_modify(drv_data
->dma_channel
, 2);
774 dma_width
= WDSIZE_16
;
776 set_dma_x_modify(drv_data
->dma_channel
, 1);
777 dma_width
= WDSIZE_8
;
780 /* poll for SPI completion before start */
781 while (!(read_STAT(drv_data
) & BIT_STAT_SPIF
))
784 /* dirty hack for autobuffer DMA mode */
785 if (drv_data
->tx_dma
== 0xFFFF) {
786 dev_dbg(&drv_data
->pdev
->dev
,
787 "doing autobuffer DMA out.\n");
789 /* no irq in autobuffer mode */
791 (DMAFLOW_AUTO
| RESTART
| dma_width
| DI_EN
);
792 set_dma_config(drv_data
->dma_channel
, dma_config
);
793 set_dma_start_addr(drv_data
->dma_channel
,
794 (unsigned long)drv_data
->tx
);
795 enable_dma(drv_data
->dma_channel
);
797 /* start SPI transfer */
798 write_CTRL(drv_data
, cr
| BIT_CTL_TIMOD_DMA_TX
);
800 /* just return here, there can only be one transfer
808 /* In dma mode, rx or tx must be NULL in one transfer */
809 dma_config
= (RESTART
| dma_width
| DI_EN
);
810 if (drv_data
->rx
!= NULL
) {
811 /* set transfer mode, and enable SPI */
812 dev_dbg(&drv_data
->pdev
->dev
, "doing DMA in to %p (size %zx)\n",
813 drv_data
->rx
, drv_data
->len_in_bytes
);
815 /* invalidate caches, if needed */
816 if (bfin_addr_dcachable((unsigned long) drv_data
->rx
))
817 invalidate_dcache_range((unsigned long) drv_data
->rx
,
818 (unsigned long) (drv_data
->rx
+
819 drv_data
->len_in_bytes
));
821 /* clear tx reg soformer data is not shifted out */
822 write_TDBR(drv_data
, 0xFFFF);
825 dma_start_addr
= (unsigned long)drv_data
->rx
;
826 cr
|= BIT_CTL_TIMOD_DMA_RX
| BIT_CTL_SENDOPT
;
828 } else if (drv_data
->tx
!= NULL
) {
829 dev_dbg(&drv_data
->pdev
->dev
, "doing DMA out.\n");
831 /* flush caches, if needed */
832 if (bfin_addr_dcachable((unsigned long) drv_data
->tx
))
833 flush_dcache_range((unsigned long) drv_data
->tx
,
834 (unsigned long) (drv_data
->tx
+
835 drv_data
->len_in_bytes
));
837 dma_start_addr
= (unsigned long)drv_data
->tx
;
838 cr
|= BIT_CTL_TIMOD_DMA_TX
;
843 /* oh man, here there be monsters ... and i dont mean the
844 * fluffy cute ones from pixar, i mean the kind that'll eat
845 * your data, kick your dog, and love it all. do *not* try
846 * and change these lines unless you (1) heavily test DMA
847 * with SPI flashes on a loaded system (e.g. ping floods),
848 * (2) know just how broken the DMA engine interaction with
849 * the SPI peripheral is, and (3) have someone else to blame
850 * when you screw it all up anyways.
852 set_dma_start_addr(drv_data
->dma_channel
, dma_start_addr
);
853 set_dma_config(drv_data
->dma_channel
, dma_config
);
854 local_irq_save(flags
);
855 enable_dma(drv_data
->dma_channel
);
856 write_CTRL(drv_data
, cr
);
857 dma_enable_irq(drv_data
->dma_channel
);
858 local_irq_restore(flags
);
861 /* IO mode write then read */
862 dev_dbg(&drv_data
->pdev
->dev
, "doing IO transfer\n");
865 /* full duplex mode */
866 BUG_ON((drv_data
->tx_end
- drv_data
->tx
) !=
867 (drv_data
->rx_end
- drv_data
->rx
));
868 dev_dbg(&drv_data
->pdev
->dev
,
869 "IO duplex: cr is 0x%x\n", cr
);
871 /* set SPI transfer mode */
872 write_CTRL(drv_data
, (cr
| CFG_SPI_WRITE
));
874 drv_data
->duplex(drv_data
);
876 if (drv_data
->tx
!= drv_data
->tx_end
)
878 } else if (drv_data
->tx
!= NULL
) {
879 /* write only half duplex */
880 dev_dbg(&drv_data
->pdev
->dev
,
881 "IO write: cr is 0x%x\n", cr
);
883 /* set SPI transfer mode */
884 write_CTRL(drv_data
, (cr
| CFG_SPI_WRITE
));
886 drv_data
->write(drv_data
);
888 if (drv_data
->tx
!= drv_data
->tx_end
)
890 } else if (drv_data
->rx
!= NULL
) {
891 /* read only half duplex */
892 dev_dbg(&drv_data
->pdev
->dev
,
893 "IO read: cr is 0x%x\n", cr
);
895 /* set SPI transfer mode */
896 write_CTRL(drv_data
, (cr
| CFG_SPI_READ
));
898 drv_data
->read(drv_data
);
899 if (drv_data
->rx
!= drv_data
->rx_end
)
903 if (!tranf_success
) {
904 dev_dbg(&drv_data
->pdev
->dev
,
905 "IO write error!\n");
906 message
->state
= ERROR_STATE
;
908 /* Update total byte transfered */
909 message
->actual_length
+= drv_data
->len_in_bytes
;
911 /* Move to next transfer of this msg */
912 message
->state
= next_transfer(drv_data
);
915 /* Schedule next transfer tasklet */
916 tasklet_schedule(&drv_data
->pump_transfers
);
921 /* pop a msg from queue and kick off real transfer */
922 static void pump_messages(struct work_struct
*work
)
924 struct driver_data
*drv_data
;
927 drv_data
= container_of(work
, struct driver_data
, pump_messages
);
929 /* Lock queue and check for queue work */
930 spin_lock_irqsave(&drv_data
->lock
, flags
);
931 if (list_empty(&drv_data
->queue
) || drv_data
->run
== QUEUE_STOPPED
) {
932 /* pumper kicked off but no work to do */
934 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
938 /* Make sure we are not already running a message */
939 if (drv_data
->cur_msg
) {
940 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
944 /* Extract head of queue */
945 drv_data
->cur_msg
= list_entry(drv_data
->queue
.next
,
946 struct spi_message
, queue
);
948 /* Setup the SSP using the per chip configuration */
949 drv_data
->cur_chip
= spi_get_ctldata(drv_data
->cur_msg
->spi
);
950 restore_state(drv_data
);
952 list_del_init(&drv_data
->cur_msg
->queue
);
954 /* Initial message state */
955 drv_data
->cur_msg
->state
= START_STATE
;
956 drv_data
->cur_transfer
= list_entry(drv_data
->cur_msg
->transfers
.next
,
957 struct spi_transfer
, transfer_list
);
959 dev_dbg(&drv_data
->pdev
->dev
, "got a message to pump, "
960 "state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
961 drv_data
->cur_chip
->baud
, drv_data
->cur_chip
->flag
,
962 drv_data
->cur_chip
->ctl_reg
);
964 dev_dbg(&drv_data
->pdev
->dev
,
965 "the first transfer len is %d\n",
966 drv_data
->cur_transfer
->len
);
968 /* Mark as busy and launch transfers */
969 tasklet_schedule(&drv_data
->pump_transfers
);
972 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
976 * got a msg to transfer, queue it in drv_data->queue.
977 * And kick off message pumper
979 static int transfer(struct spi_device
*spi
, struct spi_message
*msg
)
981 struct driver_data
*drv_data
= spi_master_get_devdata(spi
->master
);
984 spin_lock_irqsave(&drv_data
->lock
, flags
);
986 if (drv_data
->run
== QUEUE_STOPPED
) {
987 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
991 msg
->actual_length
= 0;
992 msg
->status
= -EINPROGRESS
;
993 msg
->state
= START_STATE
;
995 dev_dbg(&spi
->dev
, "adding an msg in transfer() \n");
996 list_add_tail(&msg
->queue
, &drv_data
->queue
);
998 if (drv_data
->run
== QUEUE_RUNNING
&& !drv_data
->busy
)
999 queue_work(drv_data
->workqueue
, &drv_data
->pump_messages
);
1001 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
1006 #define MAX_SPI_SSEL 7
1008 static u16 ssel
[][MAX_SPI_SSEL
] = {
1009 {P_SPI0_SSEL1
, P_SPI0_SSEL2
, P_SPI0_SSEL3
,
1010 P_SPI0_SSEL4
, P_SPI0_SSEL5
,
1011 P_SPI0_SSEL6
, P_SPI0_SSEL7
},
1013 {P_SPI1_SSEL1
, P_SPI1_SSEL2
, P_SPI1_SSEL3
,
1014 P_SPI1_SSEL4
, P_SPI1_SSEL5
,
1015 P_SPI1_SSEL6
, P_SPI1_SSEL7
},
1017 {P_SPI2_SSEL1
, P_SPI2_SSEL2
, P_SPI2_SSEL3
,
1018 P_SPI2_SSEL4
, P_SPI2_SSEL5
,
1019 P_SPI2_SSEL6
, P_SPI2_SSEL7
},
1022 /* first setup for new devices */
1023 static int setup(struct spi_device
*spi
)
1025 struct bfin5xx_spi_chip
*chip_info
= NULL
;
1026 struct chip_data
*chip
;
1027 struct driver_data
*drv_data
= spi_master_get_devdata(spi
->master
);
1030 /* Abort device setup if requested features are not supported */
1031 if (spi
->mode
& ~(SPI_CPOL
| SPI_CPHA
| SPI_LSB_FIRST
)) {
1032 dev_err(&spi
->dev
, "requested mode not fully supported\n");
1036 /* Zero (the default) here means 8 bits */
1037 if (!spi
->bits_per_word
)
1038 spi
->bits_per_word
= 8;
1040 if (spi
->bits_per_word
!= 8 && spi
->bits_per_word
!= 16)
1043 /* Only alloc (or use chip_info) on first setup */
1044 chip
= spi_get_ctldata(spi
);
1046 chip
= kzalloc(sizeof(struct chip_data
), GFP_KERNEL
);
1050 chip
->enable_dma
= 0;
1051 chip_info
= spi
->controller_data
;
1054 /* chip_info isn't always needed */
1056 /* Make sure people stop trying to set fields via ctl_reg
1057 * when they should actually be using common SPI framework.
1058 * Currently we let through: WOM EMISO PSSE GM SZ TIMOD.
1059 * Not sure if a user actually needs/uses any of these,
1060 * but let's assume (for now) they do.
1062 if (chip_info
->ctl_reg
& (SPE
|MSTR
|CPOL
|CPHA
|LSBF
|SIZE
)) {
1063 dev_err(&spi
->dev
, "do not set bits in ctl_reg "
1064 "that the SPI framework manages\n");
1068 chip
->enable_dma
= chip_info
->enable_dma
!= 0
1069 && drv_data
->master_info
->enable_dma
;
1070 chip
->ctl_reg
= chip_info
->ctl_reg
;
1071 chip
->bits_per_word
= chip_info
->bits_per_word
;
1072 chip
->cs_change_per_word
= chip_info
->cs_change_per_word
;
1073 chip
->cs_chg_udelay
= chip_info
->cs_chg_udelay
;
1076 /* translate common spi framework into our register */
1077 if (spi
->mode
& SPI_CPOL
)
1078 chip
->ctl_reg
|= CPOL
;
1079 if (spi
->mode
& SPI_CPHA
)
1080 chip
->ctl_reg
|= CPHA
;
1081 if (spi
->mode
& SPI_LSB_FIRST
)
1082 chip
->ctl_reg
|= LSBF
;
1083 /* we dont support running in slave mode (yet?) */
1084 chip
->ctl_reg
|= MSTR
;
1087 * if any one SPI chip is registered and wants DMA, request the
1088 * DMA channel for it
1090 if (chip
->enable_dma
&& !drv_data
->dma_requested
) {
1091 /* register dma irq handler */
1092 if (request_dma(drv_data
->dma_channel
, "BFIN_SPI_DMA") < 0) {
1094 "Unable to request BlackFin SPI DMA channel\n");
1097 if (set_dma_callback(drv_data
->dma_channel
,
1098 dma_irq_handler
, drv_data
) < 0) {
1099 dev_dbg(&spi
->dev
, "Unable to set dma callback\n");
1102 dma_disable_irq(drv_data
->dma_channel
);
1103 drv_data
->dma_requested
= 1;
1107 * Notice: for blackfin, the speed_hz is the value of register
1108 * SPI_BAUD, not the real baudrate
1110 chip
->baud
= hz_to_spi_baud(spi
->max_speed_hz
);
1111 spi_flg
= ~(1 << (spi
->chip_select
));
1112 chip
->flag
= ((u16
) spi_flg
<< 8) | (1 << (spi
->chip_select
));
1113 chip
->chip_select_num
= spi
->chip_select
;
1115 switch (chip
->bits_per_word
) {
1118 chip
->width
= CFG_SPI_WORDSIZE8
;
1119 chip
->read
= chip
->cs_change_per_word
?
1120 u8_cs_chg_reader
: u8_reader
;
1121 chip
->write
= chip
->cs_change_per_word
?
1122 u8_cs_chg_writer
: u8_writer
;
1123 chip
->duplex
= chip
->cs_change_per_word
?
1124 u8_cs_chg_duplex
: u8_duplex
;
1129 chip
->width
= CFG_SPI_WORDSIZE16
;
1130 chip
->read
= chip
->cs_change_per_word
?
1131 u16_cs_chg_reader
: u16_reader
;
1132 chip
->write
= chip
->cs_change_per_word
?
1133 u16_cs_chg_writer
: u16_writer
;
1134 chip
->duplex
= chip
->cs_change_per_word
?
1135 u16_cs_chg_duplex
: u16_duplex
;
1139 dev_err(&spi
->dev
, "%d bits_per_word is not supported\n",
1140 chip
->bits_per_word
);
1145 dev_dbg(&spi
->dev
, "setup spi chip %s, width is %d, dma is %d\n",
1146 spi
->modalias
, chip
->width
, chip
->enable_dma
);
1147 dev_dbg(&spi
->dev
, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1148 chip
->ctl_reg
, chip
->flag
);
1150 spi_set_ctldata(spi
, chip
);
1152 dev_dbg(&spi
->dev
, "chip select number is %d\n", chip
->chip_select_num
);
1153 if ((chip
->chip_select_num
> 0)
1154 && (chip
->chip_select_num
<= spi
->master
->num_chipselect
))
1155 peripheral_request(ssel
[spi
->master
->bus_num
]
1156 [chip
->chip_select_num
-1], spi
->modalias
);
1158 cs_deactive(drv_data
, chip
);
1164 * callback for spi framework.
1165 * clean driver specific data
1167 static void cleanup(struct spi_device
*spi
)
1169 struct chip_data
*chip
= spi_get_ctldata(spi
);
1171 if ((chip
->chip_select_num
> 0)
1172 && (chip
->chip_select_num
<= spi
->master
->num_chipselect
))
1173 peripheral_free(ssel
[spi
->master
->bus_num
]
1174 [chip
->chip_select_num
-1]);
1179 static inline int init_queue(struct driver_data
*drv_data
)
1181 INIT_LIST_HEAD(&drv_data
->queue
);
1182 spin_lock_init(&drv_data
->lock
);
1184 drv_data
->run
= QUEUE_STOPPED
;
1187 /* init transfer tasklet */
1188 tasklet_init(&drv_data
->pump_transfers
,
1189 pump_transfers
, (unsigned long)drv_data
);
1191 /* init messages workqueue */
1192 INIT_WORK(&drv_data
->pump_messages
, pump_messages
);
1193 drv_data
->workqueue
= create_singlethread_workqueue(
1194 dev_name(drv_data
->master
->dev
.parent
));
1195 if (drv_data
->workqueue
== NULL
)
1201 static inline int start_queue(struct driver_data
*drv_data
)
1203 unsigned long flags
;
1205 spin_lock_irqsave(&drv_data
->lock
, flags
);
1207 if (drv_data
->run
== QUEUE_RUNNING
|| drv_data
->busy
) {
1208 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
1212 drv_data
->run
= QUEUE_RUNNING
;
1213 drv_data
->cur_msg
= NULL
;
1214 drv_data
->cur_transfer
= NULL
;
1215 drv_data
->cur_chip
= NULL
;
1216 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
1218 queue_work(drv_data
->workqueue
, &drv_data
->pump_messages
);
1223 static inline int stop_queue(struct driver_data
*drv_data
)
1225 unsigned long flags
;
1226 unsigned limit
= 500;
1229 spin_lock_irqsave(&drv_data
->lock
, flags
);
1232 * This is a bit lame, but is optimized for the common execution path.
1233 * A wait_queue on the drv_data->busy could be used, but then the common
1234 * execution path (pump_messages) would be required to call wake_up or
1235 * friends on every SPI message. Do this instead
1237 drv_data
->run
= QUEUE_STOPPED
;
1238 while (!list_empty(&drv_data
->queue
) && drv_data
->busy
&& limit
--) {
1239 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
1241 spin_lock_irqsave(&drv_data
->lock
, flags
);
1244 if (!list_empty(&drv_data
->queue
) || drv_data
->busy
)
1247 spin_unlock_irqrestore(&drv_data
->lock
, flags
);
1252 static inline int destroy_queue(struct driver_data
*drv_data
)
1256 status
= stop_queue(drv_data
);
1260 destroy_workqueue(drv_data
->workqueue
);
1265 static int __init
bfin5xx_spi_probe(struct platform_device
*pdev
)
1267 struct device
*dev
= &pdev
->dev
;
1268 struct bfin5xx_spi_master
*platform_info
;
1269 struct spi_master
*master
;
1270 struct driver_data
*drv_data
= 0;
1271 struct resource
*res
;
1274 platform_info
= dev
->platform_data
;
1276 /* Allocate master with space for drv_data */
1277 master
= spi_alloc_master(dev
, sizeof(struct driver_data
) + 16);
1279 dev_err(&pdev
->dev
, "can not alloc spi_master\n");
1283 drv_data
= spi_master_get_devdata(master
);
1284 drv_data
->master
= master
;
1285 drv_data
->master_info
= platform_info
;
1286 drv_data
->pdev
= pdev
;
1287 drv_data
->pin_req
= platform_info
->pin_req
;
1289 master
->bus_num
= pdev
->id
;
1290 master
->num_chipselect
= platform_info
->num_chipselect
;
1291 master
->cleanup
= cleanup
;
1292 master
->setup
= setup
;
1293 master
->transfer
= transfer
;
1295 /* Find and map our resources */
1296 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
1298 dev_err(dev
, "Cannot get IORESOURCE_MEM\n");
1300 goto out_error_get_res
;
1303 drv_data
->regs_base
= ioremap(res
->start
, (res
->end
- res
->start
+ 1));
1304 if (drv_data
->regs_base
== NULL
) {
1305 dev_err(dev
, "Cannot map IO\n");
1307 goto out_error_ioremap
;
1310 drv_data
->dma_channel
= platform_get_irq(pdev
, 0);
1311 if (drv_data
->dma_channel
< 0) {
1312 dev_err(dev
, "No DMA channel specified\n");
1314 goto out_error_no_dma_ch
;
1317 /* Initial and start queue */
1318 status
= init_queue(drv_data
);
1320 dev_err(dev
, "problem initializing queue\n");
1321 goto out_error_queue_alloc
;
1324 status
= start_queue(drv_data
);
1326 dev_err(dev
, "problem starting queue\n");
1327 goto out_error_queue_alloc
;
1330 status
= peripheral_request_list(drv_data
->pin_req
, DRV_NAME
);
1332 dev_err(&pdev
->dev
, ": Requesting Peripherals failed\n");
1333 goto out_error_queue_alloc
;
1336 /* Register with the SPI framework */
1337 platform_set_drvdata(pdev
, drv_data
);
1338 status
= spi_register_master(master
);
1340 dev_err(dev
, "problem registering spi master\n");
1341 goto out_error_queue_alloc
;
1344 dev_info(dev
, "%s, Version %s, regs_base@%p, dma channel@%d\n",
1345 DRV_DESC
, DRV_VERSION
, drv_data
->regs_base
,
1346 drv_data
->dma_channel
);
1349 out_error_queue_alloc
:
1350 destroy_queue(drv_data
);
1351 out_error_no_dma_ch
:
1352 iounmap((void *) drv_data
->regs_base
);
1355 spi_master_put(master
);
1360 /* stop hardware and remove the driver */
1361 static int __devexit
bfin5xx_spi_remove(struct platform_device
*pdev
)
1363 struct driver_data
*drv_data
= platform_get_drvdata(pdev
);
1369 /* Remove the queue */
1370 status
= destroy_queue(drv_data
);
1374 /* Disable the SSP at the peripheral and SOC level */
1375 bfin_spi_disable(drv_data
);
1378 if (drv_data
->master_info
->enable_dma
) {
1379 if (dma_channel_active(drv_data
->dma_channel
))
1380 free_dma(drv_data
->dma_channel
);
1383 /* Disconnect from the SPI framework */
1384 spi_unregister_master(drv_data
->master
);
1386 peripheral_free_list(drv_data
->pin_req
);
1388 /* Prevent double remove */
1389 platform_set_drvdata(pdev
, NULL
);
1395 static int bfin5xx_spi_suspend(struct platform_device
*pdev
, pm_message_t state
)
1397 struct driver_data
*drv_data
= platform_get_drvdata(pdev
);
1400 status
= stop_queue(drv_data
);
1405 bfin_spi_disable(drv_data
);
1410 static int bfin5xx_spi_resume(struct platform_device
*pdev
)
1412 struct driver_data
*drv_data
= platform_get_drvdata(pdev
);
1415 /* Enable the SPI interface */
1416 bfin_spi_enable(drv_data
);
1418 /* Start the queue running */
1419 status
= start_queue(drv_data
);
1421 dev_err(&pdev
->dev
, "problem starting queue (%d)\n", status
);
1428 #define bfin5xx_spi_suspend NULL
1429 #define bfin5xx_spi_resume NULL
1430 #endif /* CONFIG_PM */
1432 MODULE_ALIAS("platform:bfin-spi");
1433 static struct platform_driver bfin5xx_spi_driver
= {
1436 .owner
= THIS_MODULE
,
1438 .suspend
= bfin5xx_spi_suspend
,
1439 .resume
= bfin5xx_spi_resume
,
1440 .remove
= __devexit_p(bfin5xx_spi_remove
),
1443 static int __init
bfin5xx_spi_init(void)
1445 return platform_driver_probe(&bfin5xx_spi_driver
, bfin5xx_spi_probe
);
1447 module_init(bfin5xx_spi_init
);
1449 static void __exit
bfin5xx_spi_exit(void)
1451 platform_driver_unregister(&bfin5xx_spi_driver
);
1453 module_exit(bfin5xx_spi_exit
);