2 * File: drivers/spi/bfin5xx_spi.c
4 * Bryan Wu <bryan.wu@analog.com>
6 * Luke Yang (Analog Devices Inc.)
8 * Created: March. 10th 2006
9 * Description: SPI controller driver for Blackfin BF5xx
10 * Bugs: Enter bugs at http://blackfin.uclinux.org/
13 * March 10, 2006 bfin5xx_spi.c Created. (Luke Yang)
14 * August 7, 2006 added full duplex mode (Axel Weiss & Luke Yang)
15 * July 17, 2007 add support for BF54x SPI0 controller (Bryan Wu)
17 * Copyright 2004-2007 Analog Devices Inc.
19 * This program is free software ; you can redistribute it and/or modify
20 * it under the terms of the GNU General Public License as published by
21 * the Free Software Foundation ; either version 2, or (at your option)
24 * This program is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY ; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
29 * You should have received a copy of the GNU General Public License
30 * along with this program ; see the file COPYING.
31 * If not, write to the Free Software Foundation,
32 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
35 #include <linux/init.h>
36 #include <linux/module.h>
37 #include <linux/delay.h>
38 #include <linux/device.h>
40 #include <linux/ioport.h>
41 #include <linux/irq.h>
42 #include <linux/errno.h>
43 #include <linux/interrupt.h>
44 #include <linux/platform_device.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/spi/spi.h>
47 #include <linux/workqueue.h>
50 #include <asm/portmux.h>
51 #include <asm/bfin5xx_spi.h>
53 MODULE_AUTHOR("Bryan Wu, Luke Yang");
54 MODULE_DESCRIPTION("Blackfin BF5xx SPI Contoller Driver");
55 MODULE_LICENSE("GPL");
57 #define DRV_NAME "bfin-spi-master"
58 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
60 #define DEFINE_SPI_REG(reg, off) \
61 static inline u16 read_##reg(void) \
62 { return *(volatile unsigned short*)(SPI0_REGBASE + off); } \
63 static inline void write_##reg(u16 v) \
64 {*(volatile unsigned short*)(SPI0_REGBASE + off) = v;\
67 DEFINE_SPI_REG(CTRL, 0x00)
68 DEFINE_SPI_REG(FLAG, 0x04)
69 DEFINE_SPI_REG(STAT, 0x08)
70 DEFINE_SPI_REG(TDBR, 0x0C)
71 DEFINE_SPI_REG(RDBR, 0x10)
72 DEFINE_SPI_REG(BAUD, 0x14)
73 DEFINE_SPI_REG(SHAW, 0x18)
74 #define START_STATE ((void*)0)
75 #define RUNNING_STATE ((void*)1)
76 #define DONE_STATE ((void*)2)
77 #define ERROR_STATE ((void*)-1)
78 #define QUEUE_RUNNING 0
79 #define QUEUE_STOPPED 1
83 /* Driver model hookup */
84 struct platform_device *pdev;
86 /* SPI framework hookup */
87 struct spi_master *master;
90 struct bfin5xx_spi_master *master_info;
92 /* Driver message queue */
93 struct workqueue_struct *workqueue;
94 struct work_struct pump_messages;
96 struct list_head queue;
100 /* Message Transfer pump */
101 struct tasklet_struct pump_transfers;
103 /* Current message transfer state info */
104 struct spi_message *cur_msg;
105 struct spi_transfer *cur_transfer;
106 struct chip_data *cur_chip;
119 void (*write) (struct driver_data *);
120 void (*read) (struct driver_data *);
121 void (*duplex) (struct driver_data *);
130 u8 chip_select_requested;
132 u8 width; /* 0 or 1 */
134 u8 bits_per_word; /* 8 or 16 */
135 u8 cs_change_per_word;
137 void (*write) (struct driver_data *);
138 void (*read) (struct driver_data *);
139 void (*duplex) (struct driver_data *);
142 static void bfin_spi_enable(struct driver_data *drv_data)
147 write_CTRL(cr | BIT_CTL_ENABLE);
151 static void bfin_spi_disable(struct driver_data *drv_data)
156 write_CTRL(cr & (~BIT_CTL_ENABLE));
160 /* Caculate the SPI_BAUD register value based on input HZ */
161 static u16 hz_to_spi_baud(u32 speed_hz)
163 u_long sclk = get_sclk();
164 u16 spi_baud = (sclk / (2 * speed_hz));
166 if ((sclk % (2 * speed_hz)) > 0)
172 static int flush(struct driver_data *drv_data)
174 unsigned long limit = loops_per_jiffy << 1;
176 /* wait for stop and clear stat */
177 while (!(read_STAT() & BIT_STAT_SPIF) && limit--)
180 write_STAT(BIT_STAT_CLR);
185 /* stop controller and re-config current chip*/
186 static void restore_state(struct driver_data *drv_data)
188 struct chip_data *chip = drv_data->cur_chip;
190 /* Clear status and disable clock */
191 write_STAT(BIT_STAT_CLR);
192 bfin_spi_disable(drv_data);
193 dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
195 if (!chip->chip_select_requested) {
197 dev_dbg(&drv_data->pdev->dev,
198 "chip select number is %d\n", chip->chip_select_num);
200 switch (chip->chip_select_num) {
202 peripheral_request(P_SPI0_SSEL1, DRV_NAME);
205 peripheral_request(P_SPI0_SSEL2, DRV_NAME);
208 peripheral_request(P_SPI0_SSEL3, DRV_NAME);
211 peripheral_request(P_SPI0_SSEL4, DRV_NAME);
214 peripheral_request(P_SPI0_SSEL5, DRV_NAME);
217 peripheral_request(P_SPI0_SSEL6, DRV_NAME);
220 peripheral_request(P_SPI0_SSEL7, DRV_NAME);
224 chip->chip_select_requested = 1;
227 /* Load the registers */
228 write_CTRL(chip->ctl_reg);
229 write_BAUD(chip->baud);
230 write_FLAG(chip->flag);
233 /* used to kick off transfer in rx mode */
234 static unsigned short dummy_read(void)
241 static void null_writer(struct driver_data *drv_data)
243 u8 n_bytes = drv_data->n_bytes;
245 while (drv_data->tx < drv_data->tx_end) {
247 while ((read_STAT() & BIT_STAT_TXS))
249 drv_data->tx += n_bytes;
253 static void null_reader(struct driver_data *drv_data)
255 u8 n_bytes = drv_data->n_bytes;
258 while (drv_data->rx < drv_data->rx_end) {
259 while (!(read_STAT() & BIT_STAT_RXS))
262 drv_data->rx += n_bytes;
266 static void u8_writer(struct driver_data *drv_data)
268 dev_dbg(&drv_data->pdev->dev,
269 "cr8-s is 0x%x\n", read_STAT());
270 while (drv_data->tx < drv_data->tx_end) {
271 write_TDBR(*(u8 *) (drv_data->tx));
272 while (read_STAT() & BIT_STAT_TXS)
277 /* poll for SPI completion before returning */
278 while (!(read_STAT() & BIT_STAT_SPIF))
282 static void u8_cs_chg_writer(struct driver_data *drv_data)
284 struct chip_data *chip = drv_data->cur_chip;
286 while (drv_data->tx < drv_data->tx_end) {
287 write_FLAG(chip->flag);
290 write_TDBR(*(u8 *) (drv_data->tx));
291 while (read_STAT() & BIT_STAT_TXS)
293 while (!(read_STAT() & BIT_STAT_SPIF))
295 write_FLAG(0xFF00 | chip->flag);
297 if (chip->cs_chg_udelay)
298 udelay(chip->cs_chg_udelay);
305 static void u8_reader(struct driver_data *drv_data)
307 dev_dbg(&drv_data->pdev->dev,
308 "cr-8 is 0x%x\n", read_STAT());
310 /* clear TDBR buffer before read(else it will be shifted out) */
315 while (drv_data->rx < drv_data->rx_end - 1) {
316 while (!(read_STAT() & BIT_STAT_RXS))
318 *(u8 *) (drv_data->rx) = read_RDBR();
322 while (!(read_STAT() & BIT_STAT_RXS))
324 *(u8 *) (drv_data->rx) = read_SHAW();
328 static void u8_cs_chg_reader(struct driver_data *drv_data)
330 struct chip_data *chip = drv_data->cur_chip;
332 while (drv_data->rx < drv_data->rx_end) {
333 write_FLAG(chip->flag);
336 read_RDBR(); /* kick off */
337 while (!(read_STAT() & BIT_STAT_RXS))
339 while (!(read_STAT() & BIT_STAT_SPIF))
341 *(u8 *) (drv_data->rx) = read_SHAW();
342 write_FLAG(0xFF00 | chip->flag);
344 if (chip->cs_chg_udelay)
345 udelay(chip->cs_chg_udelay);
352 static void u8_duplex(struct driver_data *drv_data)
354 /* in duplex mode, clk is triggered by writing of TDBR */
355 while (drv_data->rx < drv_data->rx_end) {
356 write_TDBR(*(u8 *) (drv_data->tx));
357 while (!(read_STAT() & BIT_STAT_SPIF))
359 while (!(read_STAT() & BIT_STAT_RXS))
361 *(u8 *) (drv_data->rx) = read_RDBR();
367 static void u8_cs_chg_duplex(struct driver_data *drv_data)
369 struct chip_data *chip = drv_data->cur_chip;
371 while (drv_data->rx < drv_data->rx_end) {
372 write_FLAG(chip->flag);
375 write_TDBR(*(u8 *) (drv_data->tx));
376 while (!(read_STAT() & BIT_STAT_SPIF))
378 while (!(read_STAT() & BIT_STAT_RXS))
380 *(u8 *) (drv_data->rx) = read_RDBR();
381 write_FLAG(0xFF00 | chip->flag);
383 if (chip->cs_chg_udelay)
384 udelay(chip->cs_chg_udelay);
392 static void u16_writer(struct driver_data *drv_data)
394 dev_dbg(&drv_data->pdev->dev,
395 "cr16 is 0x%x\n", read_STAT());
397 while (drv_data->tx < drv_data->tx_end) {
398 write_TDBR(*(u16 *) (drv_data->tx));
399 while ((read_STAT() & BIT_STAT_TXS))
404 /* poll for SPI completion before returning */
405 while (!(read_STAT() & BIT_STAT_SPIF))
409 static void u16_cs_chg_writer(struct driver_data *drv_data)
411 struct chip_data *chip = drv_data->cur_chip;
413 while (drv_data->tx < drv_data->tx_end) {
414 write_FLAG(chip->flag);
417 write_TDBR(*(u16 *) (drv_data->tx));
418 while ((read_STAT() & BIT_STAT_TXS))
420 while (!(read_STAT() & BIT_STAT_SPIF))
422 write_FLAG(0xFF00 | chip->flag);
424 if (chip->cs_chg_udelay)
425 udelay(chip->cs_chg_udelay);
432 static void u16_reader(struct driver_data *drv_data)
434 dev_dbg(&drv_data->pdev->dev,
435 "cr-16 is 0x%x\n", read_STAT());
438 while (drv_data->rx < (drv_data->rx_end - 2)) {
439 while (!(read_STAT() & BIT_STAT_RXS))
441 *(u16 *) (drv_data->rx) = read_RDBR();
445 while (!(read_STAT() & BIT_STAT_RXS))
447 *(u16 *) (drv_data->rx) = read_SHAW();
451 static void u16_cs_chg_reader(struct driver_data *drv_data)
453 struct chip_data *chip = drv_data->cur_chip;
455 while (drv_data->rx < drv_data->rx_end) {
456 write_FLAG(chip->flag);
459 read_RDBR(); /* kick off */
460 while (!(read_STAT() & BIT_STAT_RXS))
462 while (!(read_STAT() & BIT_STAT_SPIF))
464 *(u16 *) (drv_data->rx) = read_SHAW();
465 write_FLAG(0xFF00 | chip->flag);
467 if (chip->cs_chg_udelay)
468 udelay(chip->cs_chg_udelay);
475 static void u16_duplex(struct driver_data *drv_data)
477 /* in duplex mode, clk is triggered by writing of TDBR */
478 while (drv_data->tx < drv_data->tx_end) {
479 write_TDBR(*(u16 *) (drv_data->tx));
480 while (!(read_STAT() & BIT_STAT_SPIF))
482 while (!(read_STAT() & BIT_STAT_RXS))
484 *(u16 *) (drv_data->rx) = read_RDBR();
490 static void u16_cs_chg_duplex(struct driver_data *drv_data)
492 struct chip_data *chip = drv_data->cur_chip;
494 while (drv_data->tx < drv_data->tx_end) {
495 write_FLAG(chip->flag);
498 write_TDBR(*(u16 *) (drv_data->tx));
499 while (!(read_STAT() & BIT_STAT_SPIF))
501 while (!(read_STAT() & BIT_STAT_RXS))
503 *(u16 *) (drv_data->rx) = read_RDBR();
504 write_FLAG(0xFF00 | chip->flag);
506 if (chip->cs_chg_udelay)
507 udelay(chip->cs_chg_udelay);
515 /* test if ther is more transfer to be done */
516 static void *next_transfer(struct driver_data *drv_data)
518 struct spi_message *msg = drv_data->cur_msg;
519 struct spi_transfer *trans = drv_data->cur_transfer;
521 /* Move to next transfer */
522 if (trans->transfer_list.next != &msg->transfers) {
523 drv_data->cur_transfer =
524 list_entry(trans->transfer_list.next,
525 struct spi_transfer, transfer_list);
526 return RUNNING_STATE;
532 * caller already set message->status;
533 * dma and pio irqs are blocked give finished message back
535 static void giveback(struct driver_data *drv_data)
537 struct spi_transfer *last_transfer;
539 struct spi_message *msg;
541 spin_lock_irqsave(&drv_data->lock, flags);
542 msg = drv_data->cur_msg;
543 drv_data->cur_msg = NULL;
544 drv_data->cur_transfer = NULL;
545 drv_data->cur_chip = NULL;
546 queue_work(drv_data->workqueue, &drv_data->pump_messages);
547 spin_unlock_irqrestore(&drv_data->lock, flags);
549 last_transfer = list_entry(msg->transfers.prev,
550 struct spi_transfer, transfer_list);
554 /* disable chip select signal. And not stop spi in autobuffer mode */
555 if (drv_data->tx_dma != 0xFFFF) {
557 bfin_spi_disable(drv_data);
561 msg->complete(msg->context);
564 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
566 struct driver_data *drv_data = (struct driver_data *)dev_id;
567 struct spi_message *msg = drv_data->cur_msg;
569 dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");
570 clear_dma_irqstat(CH_SPI);
572 /* Wait for DMA to complete */
573 while (get_dma_curr_irqstat(CH_SPI) & DMA_RUN)
577 * wait for the last transaction shifted out. HRM states:
578 * at this point there may still be data in the SPI DMA FIFO waiting
579 * to be transmitted ... software needs to poll TXS in the SPI_STAT
580 * register until it goes low for 2 successive reads
582 if (drv_data->tx != NULL) {
583 while ((bfin_read_SPI_STAT() & TXS) ||
584 (bfin_read_SPI_STAT() & TXS))
588 while (!(bfin_read_SPI_STAT() & SPIF))
591 bfin_spi_disable(drv_data);
593 msg->actual_length += drv_data->len_in_bytes;
595 /* Move to next transfer */
596 msg->state = next_transfer(drv_data);
598 /* Schedule transfer tasklet */
599 tasklet_schedule(&drv_data->pump_transfers);
601 /* free the irq handler before next transfer */
602 dev_dbg(&drv_data->pdev->dev,
603 "disable dma channel irq%d\n",
605 dma_disable_irq(CH_SPI);
610 static void pump_transfers(unsigned long data)
612 struct driver_data *drv_data = (struct driver_data *)data;
613 struct spi_message *message = NULL;
614 struct spi_transfer *transfer = NULL;
615 struct spi_transfer *previous = NULL;
616 struct chip_data *chip = NULL;
618 u16 cr, dma_width, dma_config;
619 u32 tranf_success = 1;
621 /* Get current state information */
622 message = drv_data->cur_msg;
623 transfer = drv_data->cur_transfer;
624 chip = drv_data->cur_chip;
627 * if msg is error or done, report it back using complete() callback
630 /* Handle for abort */
631 if (message->state == ERROR_STATE) {
632 message->status = -EIO;
637 /* Handle end of message */
638 if (message->state == DONE_STATE) {
644 /* Delay if requested at end of transfer */
645 if (message->state == RUNNING_STATE) {
646 previous = list_entry(transfer->transfer_list.prev,
647 struct spi_transfer, transfer_list);
648 if (previous->delay_usecs)
649 udelay(previous->delay_usecs);
652 /* Setup the transfer state based on the type of transfer */
653 if (flush(drv_data) == 0) {
654 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
655 message->status = -EIO;
660 if (transfer->tx_buf != NULL) {
661 drv_data->tx = (void *)transfer->tx_buf;
662 drv_data->tx_end = drv_data->tx + transfer->len;
663 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
664 transfer->tx_buf, drv_data->tx_end);
669 if (transfer->rx_buf != NULL) {
670 drv_data->rx = transfer->rx_buf;
671 drv_data->rx_end = drv_data->rx + transfer->len;
672 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
673 transfer->rx_buf, drv_data->rx_end);
678 drv_data->rx_dma = transfer->rx_dma;
679 drv_data->tx_dma = transfer->tx_dma;
680 drv_data->len_in_bytes = transfer->len;
683 if (width == CFG_SPI_WORDSIZE16) {
684 drv_data->len = (transfer->len) >> 1;
686 drv_data->len = transfer->len;
688 drv_data->write = drv_data->tx ? chip->write : null_writer;
689 drv_data->read = drv_data->rx ? chip->read : null_reader;
690 drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
691 dev_dbg(&drv_data->pdev->dev, "transfer: ",
692 "drv_data->write is %p, chip->write is %p, null_wr is %p\n",
693 drv_data->write, chip->write, null_writer);
695 /* speed and width has been set on per message */
696 message->state = RUNNING_STATE;
699 /* restore spi status for each spi transfer */
700 if (transfer->speed_hz) {
701 write_BAUD(hz_to_spi_baud(transfer->speed_hz));
703 write_BAUD(chip->baud);
705 write_FLAG(chip->flag);
707 dev_dbg(&drv_data->pdev->dev,
708 "now pumping a transfer: width is %d, len is %d\n",
709 width, transfer->len);
712 * Try to map dma buffer and do a dma transfer if
713 * successful use different way to r/w according to
714 * drv_data->cur_chip->enable_dma
716 if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
718 write_STAT(BIT_STAT_CLR);
720 clear_dma_irqstat(CH_SPI);
721 bfin_spi_disable(drv_data);
723 /* config dma channel */
724 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
725 if (width == CFG_SPI_WORDSIZE16) {
726 set_dma_x_count(CH_SPI, drv_data->len);
727 set_dma_x_modify(CH_SPI, 2);
728 dma_width = WDSIZE_16;
730 set_dma_x_count(CH_SPI, drv_data->len);
731 set_dma_x_modify(CH_SPI, 1);
732 dma_width = WDSIZE_8;
735 /* set transfer width,direction. And enable spi */
736 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
738 /* dirty hack for autobuffer DMA mode */
739 if (drv_data->tx_dma == 0xFFFF) {
740 dev_dbg(&drv_data->pdev->dev,
741 "doing autobuffer DMA out.\n");
743 /* no irq in autobuffer mode */
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);
749 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
750 (CFG_SPI_ENABLE << 14));
752 /* just return here, there can only be one transfer in this mode */
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 dev_dbg(&drv_data->pdev->dev, "doing DMA in.\n");
763 /* disable SPI before write to TDBR */
764 write_CTRL(cr & ~BIT_CTL_ENABLE);
766 /* clear tx reg soformer data is not shifted out */
769 set_dma_x_count(CH_SPI, drv_data->len);
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);
779 CFG_SPI_DMAREAD | (width << 8) | (CFG_SPI_ENABLE <<
781 /* set transfer mode, and enable SPI */
783 } else if (drv_data->tx != NULL) {
784 dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
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);
793 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
794 (CFG_SPI_ENABLE << 14));
798 /* IO mode write then read */
799 dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
801 write_STAT(BIT_STAT_CLR);
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));
808 cr |= CFG_SPI_WRITE | (width << 8) |
809 (CFG_SPI_ENABLE << 14);
810 dev_dbg(&drv_data->pdev->dev,
811 "IO duplex: cr is 0x%x\n", cr);
816 drv_data->duplex(drv_data);
818 if (drv_data->tx != drv_data->tx_end)
820 } else if (drv_data->tx != NULL) {
821 /* write only half duplex */
822 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
823 cr |= CFG_SPI_WRITE | (width << 8) |
824 (CFG_SPI_ENABLE << 14);
825 dev_dbg(&drv_data->pdev->dev,
826 "IO write: cr is 0x%x\n", cr);
831 drv_data->write(drv_data);
833 if (drv_data->tx != drv_data->tx_end)
835 } else if (drv_data->rx != NULL) {
836 /* read only half duplex */
837 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
838 cr |= CFG_SPI_READ | (width << 8) |
839 (CFG_SPI_ENABLE << 14);
840 dev_dbg(&drv_data->pdev->dev,
841 "IO read: cr is 0x%x\n", cr);
846 drv_data->read(drv_data);
847 if (drv_data->rx != drv_data->rx_end)
851 if (!tranf_success) {
852 dev_dbg(&drv_data->pdev->dev,
853 "IO write error!\n");
854 message->state = ERROR_STATE;
856 /* Update total byte transfered */
857 message->actual_length += drv_data->len;
859 /* Move to next transfer of this msg */
860 message->state = next_transfer(drv_data);
863 /* Schedule next transfer tasklet */
864 tasklet_schedule(&drv_data->pump_transfers);
869 /* pop a msg from queue and kick off real transfer */
870 static void pump_messages(struct work_struct *work)
872 struct driver_data *drv_data;
875 drv_data = container_of(work, struct driver_data, pump_messages);
877 /* Lock queue and check for queue work */
878 spin_lock_irqsave(&drv_data->lock, flags);
879 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
880 /* pumper kicked off but no work to do */
882 spin_unlock_irqrestore(&drv_data->lock, flags);
886 /* Make sure we are not already running a message */
887 if (drv_data->cur_msg) {
888 spin_unlock_irqrestore(&drv_data->lock, flags);
892 /* Extract head of queue */
893 drv_data->cur_msg = list_entry(drv_data->queue.next,
894 struct spi_message, queue);
895 list_del_init(&drv_data->cur_msg->queue);
897 /* Initial message state */
898 drv_data->cur_msg->state = START_STATE;
899 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
900 struct spi_transfer, transfer_list);
902 /* Setup the SSP using the per chip configuration */
903 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
904 restore_state(drv_data);
905 dev_dbg(&drv_data->pdev->dev,
906 "got a message to pump, state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
907 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
908 drv_data->cur_chip->ctl_reg);
910 dev_dbg(&drv_data->pdev->dev,
911 "the first transfer len is %d\n",
912 drv_data->cur_transfer->len);
914 /* Mark as busy and launch transfers */
915 tasklet_schedule(&drv_data->pump_transfers);
918 spin_unlock_irqrestore(&drv_data->lock, flags);
922 * got a msg to transfer, queue it in drv_data->queue.
923 * And kick off message pumper
925 static int transfer(struct spi_device *spi, struct spi_message *msg)
927 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
930 spin_lock_irqsave(&drv_data->lock, flags);
932 if (drv_data->run == QUEUE_STOPPED) {
933 spin_unlock_irqrestore(&drv_data->lock, flags);
937 msg->actual_length = 0;
938 msg->status = -EINPROGRESS;
939 msg->state = START_STATE;
941 dev_dbg(&spi->dev, "adding an msg in transfer() \n");
942 list_add_tail(&msg->queue, &drv_data->queue);
944 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
945 queue_work(drv_data->workqueue, &drv_data->pump_messages);
947 spin_unlock_irqrestore(&drv_data->lock, flags);
952 /* first setup for new devices */
953 static int setup(struct spi_device *spi)
955 struct bfin5xx_spi_chip *chip_info = NULL;
956 struct chip_data *chip;
957 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
960 /* Abort device setup if requested features are not supported */
961 if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
962 dev_err(&spi->dev, "requested mode not fully supported\n");
966 /* Zero (the default) here means 8 bits */
967 if (!spi->bits_per_word)
968 spi->bits_per_word = 8;
970 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
973 /* Only alloc (or use chip_info) on first setup */
974 chip = spi_get_ctldata(spi);
976 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
980 chip->enable_dma = 0;
981 chip_info = spi->controller_data;
984 /* chip_info isn't always needed */
986 chip->enable_dma = chip_info->enable_dma != 0
987 && drv_data->master_info->enable_dma;
988 chip->ctl_reg = chip_info->ctl_reg;
989 chip->bits_per_word = chip_info->bits_per_word;
990 chip->cs_change_per_word = chip_info->cs_change_per_word;
991 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
994 /* translate common spi framework into our register */
995 if (spi->mode & SPI_CPOL)
996 chip->ctl_reg |= CPOL;
997 if (spi->mode & SPI_CPHA)
998 chip->ctl_reg |= CPHA;
999 if (spi->mode & SPI_LSB_FIRST)
1000 chip->ctl_reg |= LSBF;
1001 /* we dont support running in slave mode (yet?) */
1002 chip->ctl_reg |= MSTR;
1005 * if any one SPI chip is registered and wants DMA, request the
1006 * DMA channel for it
1008 if (chip->enable_dma && !dma_requested) {
1009 /* register dma irq handler */
1010 if (request_dma(CH_SPI, "BF53x_SPI_DMA") < 0) {
1012 "Unable to request BlackFin SPI DMA channel\n");
1015 if (set_dma_callback(CH_SPI, (void *)dma_irq_handler, drv_data)
1017 dev_dbg(&spi->dev, "Unable to set dma callback\n");
1020 dma_disable_irq(CH_SPI);
1025 * Notice: for blackfin, the speed_hz is the value of register
1026 * SPI_BAUD, not the real baudrate
1028 chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1029 spi_flg = ~(1 << (spi->chip_select));
1030 chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
1031 chip->chip_select_num = spi->chip_select;
1033 switch (chip->bits_per_word) {
1036 chip->width = CFG_SPI_WORDSIZE8;
1037 chip->read = chip->cs_change_per_word ?
1038 u8_cs_chg_reader : u8_reader;
1039 chip->write = chip->cs_change_per_word ?
1040 u8_cs_chg_writer : u8_writer;
1041 chip->duplex = chip->cs_change_per_word ?
1042 u8_cs_chg_duplex : u8_duplex;
1047 chip->width = CFG_SPI_WORDSIZE16;
1048 chip->read = chip->cs_change_per_word ?
1049 u16_cs_chg_reader : u16_reader;
1050 chip->write = chip->cs_change_per_word ?
1051 u16_cs_chg_writer : u16_writer;
1052 chip->duplex = chip->cs_change_per_word ?
1053 u16_cs_chg_duplex : u16_duplex;
1057 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1058 chip->bits_per_word);
1063 dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1064 spi->modalias, chip->width, chip->enable_dma);
1065 dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1066 chip->ctl_reg, chip->flag);
1068 spi_set_ctldata(spi, chip);
1074 * callback for spi framework.
1075 * clean driver specific data
1077 static void cleanup(struct spi_device *spi)
1079 struct chip_data *chip = spi_get_ctldata(spi);
1084 static inline int init_queue(struct driver_data *drv_data)
1086 INIT_LIST_HEAD(&drv_data->queue);
1087 spin_lock_init(&drv_data->lock);
1089 drv_data->run = QUEUE_STOPPED;
1092 /* init transfer tasklet */
1093 tasklet_init(&drv_data->pump_transfers,
1094 pump_transfers, (unsigned long)drv_data);
1096 /* init messages workqueue */
1097 INIT_WORK(&drv_data->pump_messages, pump_messages);
1098 drv_data->workqueue =
1099 create_singlethread_workqueue(drv_data->master->dev.parent->bus_id);
1100 if (drv_data->workqueue == NULL)
1106 static inline int start_queue(struct driver_data *drv_data)
1108 unsigned long flags;
1110 spin_lock_irqsave(&drv_data->lock, flags);
1112 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1113 spin_unlock_irqrestore(&drv_data->lock, flags);
1117 drv_data->run = QUEUE_RUNNING;
1118 drv_data->cur_msg = NULL;
1119 drv_data->cur_transfer = NULL;
1120 drv_data->cur_chip = NULL;
1121 spin_unlock_irqrestore(&drv_data->lock, flags);
1123 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1128 static inline int stop_queue(struct driver_data *drv_data)
1130 unsigned long flags;
1131 unsigned limit = 500;
1134 spin_lock_irqsave(&drv_data->lock, flags);
1137 * This is a bit lame, but is optimized for the common execution path.
1138 * A wait_queue on the drv_data->busy could be used, but then the common
1139 * execution path (pump_messages) would be required to call wake_up or
1140 * friends on every SPI message. Do this instead
1142 drv_data->run = QUEUE_STOPPED;
1143 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1144 spin_unlock_irqrestore(&drv_data->lock, flags);
1146 spin_lock_irqsave(&drv_data->lock, flags);
1149 if (!list_empty(&drv_data->queue) || drv_data->busy)
1152 spin_unlock_irqrestore(&drv_data->lock, flags);
1157 static inline int destroy_queue(struct driver_data *drv_data)
1161 status = stop_queue(drv_data);
1165 destroy_workqueue(drv_data->workqueue);
1170 static int __init bfin5xx_spi_probe(struct platform_device *pdev)
1172 struct device *dev = &pdev->dev;
1173 struct bfin5xx_spi_master *platform_info;
1174 struct spi_master *master;
1175 struct driver_data *drv_data = 0;
1178 platform_info = dev->platform_data;
1180 /* Allocate master with space for drv_data */
1181 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1183 dev_err(&pdev->dev, "can not alloc spi_master\n");
1187 if (peripheral_request(P_SPI0_SCK, DRV_NAME) ||
1188 peripheral_request(P_SPI0_MISO, DRV_NAME) ||
1189 peripheral_request(P_SPI0_MOSI, DRV_NAME)) {
1191 dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
1192 goto out_error_queue_alloc;
1195 drv_data = spi_master_get_devdata(master);
1196 drv_data->master = master;
1197 drv_data->master_info = platform_info;
1198 drv_data->pdev = pdev;
1200 master->bus_num = pdev->id;
1201 master->num_chipselect = platform_info->num_chipselect;
1202 master->cleanup = cleanup;
1203 master->setup = setup;
1204 master->transfer = transfer;
1206 /* Initial and start queue */
1207 status = init_queue(drv_data);
1209 dev_err(&pdev->dev, "problem initializing queue\n");
1210 goto out_error_queue_alloc;
1212 status = start_queue(drv_data);
1214 dev_err(&pdev->dev, "problem starting queue\n");
1215 goto out_error_queue_alloc;
1218 /* Register with the SPI framework */
1219 platform_set_drvdata(pdev, drv_data);
1220 status = spi_register_master(master);
1222 dev_err(&pdev->dev, "problem registering spi master\n");
1223 goto out_error_queue_alloc;
1225 dev_dbg(&pdev->dev, "controller probe successfully\n");
1228 out_error_queue_alloc:
1229 destroy_queue(drv_data);
1230 spi_master_put(master);
1234 /* stop hardware and remove the driver */
1235 static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
1237 struct driver_data *drv_data = platform_get_drvdata(pdev);
1243 /* Remove the queue */
1244 status = destroy_queue(drv_data);
1248 /* Disable the SSP at the peripheral and SOC level */
1249 bfin_spi_disable(drv_data);
1252 if (drv_data->master_info->enable_dma) {
1253 if (dma_channel_active(CH_SPI))
1257 /* Disconnect from the SPI framework */
1258 spi_unregister_master(drv_data->master);
1260 /* Prevent double remove */
1261 platform_set_drvdata(pdev, NULL);
1267 static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1269 struct driver_data *drv_data = platform_get_drvdata(pdev);
1272 status = stop_queue(drv_data);
1277 bfin_spi_disable(drv_data);
1282 static int bfin5xx_spi_resume(struct platform_device *pdev)
1284 struct driver_data *drv_data = platform_get_drvdata(pdev);
1287 /* Enable the SPI interface */
1288 bfin_spi_enable(drv_data);
1290 /* Start the queue running */
1291 status = start_queue(drv_data);
1293 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1300 #define bfin5xx_spi_suspend NULL
1301 #define bfin5xx_spi_resume NULL
1302 #endif /* CONFIG_PM */
1304 MODULE_ALIAS("bfin-spi-master"); /* for platform bus hotplug */
1305 static struct platform_driver bfin5xx_spi_driver = {
1307 .name = "bfin-spi-master",
1308 .owner = THIS_MODULE,
1310 .suspend = bfin5xx_spi_suspend,
1311 .resume = bfin5xx_spi_resume,
1312 .remove = __devexit_p(bfin5xx_spi_remove),
1315 static int __init bfin5xx_spi_init(void)
1317 return platform_driver_probe(&bfin5xx_spi_driver, bfin5xx_spi_probe);
1319 module_init(bfin5xx_spi_init);
1321 static void __exit bfin5xx_spi_exit(void)
1323 platform_driver_unregister(&bfin5xx_spi_driver);
1325 module_exit(bfin5xx_spi_exit);