2 * File: drivers/spi/bfin5xx_spi.c
4 * Author: Luke Yang (Analog Devices Inc.)
6 * Created: March. 10th 2006
7 * Description: SPI controller driver for Blackfin 5xx
8 * Bugs: Enter bugs at http://blackfin.uclinux.org/
11 * March 10, 2006 bfin5xx_spi.c Created. (Luke Yang)
12 * August 7, 2006 added full duplex mode (Axel Weiss & Luke Yang)
14 * Copyright 2004-2006 Analog Devices Inc.
16 * This program is free software ; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation ; either version 2, or (at your option)
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY ; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program ; see the file COPYING.
28 * If not, write to the Free Software Foundation,
29 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
32 #include <linux/init.h>
33 #include <linux/module.h>
34 #include <linux/device.h>
35 #include <linux/ioport.h>
36 #include <linux/errno.h>
37 #include <linux/interrupt.h>
38 #include <linux/platform_device.h>
39 #include <linux/dma-mapping.h>
40 #include <linux/spi/spi.h>
41 #include <linux/workqueue.h>
42 #include <linux/delay.h>
46 #include <asm/delay.h>
49 #include <asm/bfin5xx_spi.h>
51 MODULE_AUTHOR("Luke Yang");
52 MODULE_DESCRIPTION("Blackfin 5xx SPI Contoller");
53 MODULE_LICENSE("GPL");
55 #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0)
57 #define DEFINE_SPI_REG(reg, off) \
58 static inline u16 read_##reg(void) \
59 { return *(volatile unsigned short*)(SPI0_REGBASE + off); } \
60 static inline void write_##reg(u16 v) \
61 {*(volatile unsigned short*)(SPI0_REGBASE + off) = v;\
64 DEFINE_SPI_REG(CTRL, 0x00)
65 DEFINE_SPI_REG(FLAG, 0x04)
66 DEFINE_SPI_REG(STAT, 0x08)
67 DEFINE_SPI_REG(TDBR, 0x0C)
68 DEFINE_SPI_REG(RDBR, 0x10)
69 DEFINE_SPI_REG(BAUD, 0x14)
70 DEFINE_SPI_REG(SHAW, 0x18)
71 #define START_STATE ((void*)0)
72 #define RUNNING_STATE ((void*)1)
73 #define DONE_STATE ((void*)2)
74 #define ERROR_STATE ((void*)-1)
75 #define QUEUE_RUNNING 0
76 #define QUEUE_STOPPED 1
80 /* Driver model hookup */
81 struct platform_device *pdev;
83 /* SPI framework hookup */
84 struct spi_master *master;
87 struct bfin5xx_spi_master *master_info;
89 /* Driver message queue */
90 struct workqueue_struct *workqueue;
91 struct work_struct pump_messages;
93 struct list_head queue;
97 /* Message Transfer pump */
98 struct tasklet_struct pump_transfers;
100 /* Current message transfer state info */
101 struct spi_message *cur_msg;
102 struct spi_transfer *cur_transfer;
103 struct chip_data *cur_chip;
116 void (*write) (struct driver_data *);
117 void (*read) (struct driver_data *);
118 void (*duplex) (struct driver_data *);
128 u8 width; /* 0 or 1 */
130 u8 bits_per_word; /* 8 or 16 */
131 u8 cs_change_per_word;
133 void (*write) (struct driver_data *);
134 void (*read) (struct driver_data *);
135 void (*duplex) (struct driver_data *);
138 static void bfin_spi_enable(struct driver_data *drv_data)
143 write_CTRL(cr | BIT_CTL_ENABLE);
147 static void bfin_spi_disable(struct driver_data *drv_data)
152 write_CTRL(cr & (~BIT_CTL_ENABLE));
156 /* Caculate the SPI_BAUD register value based on input HZ */
157 static u16 hz_to_spi_baud(u32 speed_hz)
159 u_long sclk = get_sclk();
160 u16 spi_baud = (sclk / (2 * speed_hz));
162 if ((sclk % (2 * speed_hz)) > 0)
168 static int flush(struct driver_data *drv_data)
170 unsigned long limit = loops_per_jiffy << 1;
172 /* wait for stop and clear stat */
173 while (!(read_STAT() & BIT_STAT_SPIF) && limit--)
176 write_STAT(BIT_STAT_CLR);
181 /* stop controller and re-config current chip*/
182 static void restore_state(struct driver_data *drv_data)
184 struct chip_data *chip = drv_data->cur_chip;
186 /* Clear status and disable clock */
187 write_STAT(BIT_STAT_CLR);
188 bfin_spi_disable(drv_data);
189 dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
191 #if defined(CONFIG_BF534) || defined(CONFIG_BF536) || defined(CONFIG_BF537)
192 dev_dbg(&drv_data->pdev->dev,
193 "chip select number is %d\n", chip->chip_select_num);
195 switch (chip->chip_select_num) {
197 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3c00);
203 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJSE_SPI);
205 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
210 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS4E_SPI);
212 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3840);
217 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS5E_SPI);
219 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3820);
224 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS6E_SPI);
226 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3810);
231 bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJCE_SPI);
233 bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800);
239 /* Load the registers */
240 write_CTRL(chip->ctl_reg);
241 write_BAUD(chip->baud);
242 write_FLAG(chip->flag);
245 /* used to kick off transfer in rx mode */
246 static unsigned short dummy_read(void)
253 static void null_writer(struct driver_data *drv_data)
255 u8 n_bytes = drv_data->n_bytes;
257 while (drv_data->tx < drv_data->tx_end) {
259 while ((read_STAT() & BIT_STAT_TXS))
261 drv_data->tx += n_bytes;
265 static void null_reader(struct driver_data *drv_data)
267 u8 n_bytes = drv_data->n_bytes;
270 while (drv_data->rx < drv_data->rx_end) {
271 while (!(read_STAT() & BIT_STAT_RXS))
274 drv_data->rx += n_bytes;
278 static void u8_writer(struct driver_data *drv_data)
280 dev_dbg(&drv_data->pdev->dev,
281 "cr8-s is 0x%x\n", read_STAT());
282 while (drv_data->tx < drv_data->tx_end) {
283 write_TDBR(*(u8 *) (drv_data->tx));
284 while (read_STAT() & BIT_STAT_TXS)
289 /* poll for SPI completion before returning */
290 while (!(read_STAT() & BIT_STAT_SPIF))
294 static void u8_cs_chg_writer(struct driver_data *drv_data)
296 struct chip_data *chip = drv_data->cur_chip;
298 while (drv_data->tx < drv_data->tx_end) {
299 write_FLAG(chip->flag);
302 write_TDBR(*(u8 *) (drv_data->tx));
303 while (read_STAT() & BIT_STAT_TXS)
305 while (!(read_STAT() & BIT_STAT_SPIF))
307 write_FLAG(0xFF00 | chip->flag);
309 if (chip->cs_chg_udelay)
310 udelay(chip->cs_chg_udelay);
317 static void u8_reader(struct driver_data *drv_data)
319 dev_dbg(&drv_data->pdev->dev,
320 "cr-8 is 0x%x\n", read_STAT());
322 /* clear TDBR buffer before read(else it will be shifted out) */
327 while (drv_data->rx < drv_data->rx_end - 1) {
328 while (!(read_STAT() & BIT_STAT_RXS))
330 *(u8 *) (drv_data->rx) = read_RDBR();
334 while (!(read_STAT() & BIT_STAT_RXS))
336 *(u8 *) (drv_data->rx) = read_SHAW();
340 static void u8_cs_chg_reader(struct driver_data *drv_data)
342 struct chip_data *chip = drv_data->cur_chip;
344 while (drv_data->rx < drv_data->rx_end) {
345 write_FLAG(chip->flag);
348 read_RDBR(); /* kick off */
349 while (!(read_STAT() & BIT_STAT_RXS))
351 while (!(read_STAT() & BIT_STAT_SPIF))
353 *(u8 *) (drv_data->rx) = read_SHAW();
354 write_FLAG(0xFF00 | chip->flag);
356 if (chip->cs_chg_udelay)
357 udelay(chip->cs_chg_udelay);
364 static void u8_duplex(struct driver_data *drv_data)
366 /* in duplex mode, clk is triggered by writing of TDBR */
367 while (drv_data->rx < drv_data->rx_end) {
368 write_TDBR(*(u8 *) (drv_data->tx));
369 while (!(read_STAT() & BIT_STAT_SPIF))
371 while (!(read_STAT() & BIT_STAT_RXS))
373 *(u8 *) (drv_data->rx) = read_RDBR();
379 static void u8_cs_chg_duplex(struct driver_data *drv_data)
381 struct chip_data *chip = drv_data->cur_chip;
383 while (drv_data->rx < drv_data->rx_end) {
384 write_FLAG(chip->flag);
387 write_TDBR(*(u8 *) (drv_data->tx));
388 while (!(read_STAT() & BIT_STAT_SPIF))
390 while (!(read_STAT() & BIT_STAT_RXS))
392 *(u8 *) (drv_data->rx) = read_RDBR();
393 write_FLAG(0xFF00 | chip->flag);
395 if (chip->cs_chg_udelay)
396 udelay(chip->cs_chg_udelay);
404 static void u16_writer(struct driver_data *drv_data)
406 dev_dbg(&drv_data->pdev->dev,
407 "cr16 is 0x%x\n", read_STAT());
409 while (drv_data->tx < drv_data->tx_end) {
410 write_TDBR(*(u16 *) (drv_data->tx));
411 while ((read_STAT() & BIT_STAT_TXS))
416 /* poll for SPI completion before returning */
417 while (!(read_STAT() & BIT_STAT_SPIF))
421 static void u16_cs_chg_writer(struct driver_data *drv_data)
423 struct chip_data *chip = drv_data->cur_chip;
425 while (drv_data->tx < drv_data->tx_end) {
426 write_FLAG(chip->flag);
429 write_TDBR(*(u16 *) (drv_data->tx));
430 while ((read_STAT() & BIT_STAT_TXS))
432 while (!(read_STAT() & BIT_STAT_SPIF))
434 write_FLAG(0xFF00 | chip->flag);
436 if (chip->cs_chg_udelay)
437 udelay(chip->cs_chg_udelay);
444 static void u16_reader(struct driver_data *drv_data)
446 dev_dbg(&drv_data->pdev->dev,
447 "cr-16 is 0x%x\n", read_STAT());
450 while (drv_data->rx < (drv_data->rx_end - 2)) {
451 while (!(read_STAT() & BIT_STAT_RXS))
453 *(u16 *) (drv_data->rx) = read_RDBR();
457 while (!(read_STAT() & BIT_STAT_RXS))
459 *(u16 *) (drv_data->rx) = read_SHAW();
463 static void u16_cs_chg_reader(struct driver_data *drv_data)
465 struct chip_data *chip = drv_data->cur_chip;
467 while (drv_data->rx < drv_data->rx_end) {
468 write_FLAG(chip->flag);
471 read_RDBR(); /* kick off */
472 while (!(read_STAT() & BIT_STAT_RXS))
474 while (!(read_STAT() & BIT_STAT_SPIF))
476 *(u16 *) (drv_data->rx) = read_SHAW();
477 write_FLAG(0xFF00 | chip->flag);
479 if (chip->cs_chg_udelay)
480 udelay(chip->cs_chg_udelay);
487 static void u16_duplex(struct driver_data *drv_data)
489 /* in duplex mode, clk is triggered by writing of TDBR */
490 while (drv_data->tx < drv_data->tx_end) {
491 write_TDBR(*(u16 *) (drv_data->tx));
492 while (!(read_STAT() & BIT_STAT_SPIF))
494 while (!(read_STAT() & BIT_STAT_RXS))
496 *(u16 *) (drv_data->rx) = read_RDBR();
502 static void u16_cs_chg_duplex(struct driver_data *drv_data)
504 struct chip_data *chip = drv_data->cur_chip;
506 while (drv_data->tx < drv_data->tx_end) {
507 write_FLAG(chip->flag);
510 write_TDBR(*(u16 *) (drv_data->tx));
511 while (!(read_STAT() & BIT_STAT_SPIF))
513 while (!(read_STAT() & BIT_STAT_RXS))
515 *(u16 *) (drv_data->rx) = read_RDBR();
516 write_FLAG(0xFF00 | chip->flag);
518 if (chip->cs_chg_udelay)
519 udelay(chip->cs_chg_udelay);
527 /* test if ther is more transfer to be done */
528 static void *next_transfer(struct driver_data *drv_data)
530 struct spi_message *msg = drv_data->cur_msg;
531 struct spi_transfer *trans = drv_data->cur_transfer;
533 /* Move to next transfer */
534 if (trans->transfer_list.next != &msg->transfers) {
535 drv_data->cur_transfer =
536 list_entry(trans->transfer_list.next,
537 struct spi_transfer, transfer_list);
538 return RUNNING_STATE;
544 * caller already set message->status;
545 * dma and pio irqs are blocked give finished message back
547 static void giveback(struct driver_data *drv_data)
549 struct spi_transfer *last_transfer;
551 struct spi_message *msg;
553 spin_lock_irqsave(&drv_data->lock, flags);
554 msg = drv_data->cur_msg;
555 drv_data->cur_msg = NULL;
556 drv_data->cur_transfer = NULL;
557 drv_data->cur_chip = NULL;
558 queue_work(drv_data->workqueue, &drv_data->pump_messages);
559 spin_unlock_irqrestore(&drv_data->lock, flags);
561 last_transfer = list_entry(msg->transfers.prev,
562 struct spi_transfer, transfer_list);
566 /* disable chip select signal. And not stop spi in autobuffer mode */
567 if (drv_data->tx_dma != 0xFFFF) {
569 bfin_spi_disable(drv_data);
573 msg->complete(msg->context);
576 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
578 struct driver_data *drv_data = (struct driver_data *)dev_id;
579 struct spi_message *msg = drv_data->cur_msg;
581 dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");
582 clear_dma_irqstat(CH_SPI);
584 /* Wait for DMA to complete */
585 while (get_dma_curr_irqstat(CH_SPI) & DMA_RUN)
589 * wait for the last transaction shifted out. HRM states:
590 * at this point there may still be data in the SPI DMA FIFO waiting
591 * to be transmitted ... software needs to poll TXS in the SPI_STAT
592 * register until it goes low for 2 successive reads
594 if (drv_data->tx != NULL) {
595 while ((bfin_read_SPI_STAT() & TXS) ||
596 (bfin_read_SPI_STAT() & TXS))
600 while (!(bfin_read_SPI_STAT() & SPIF))
603 bfin_spi_disable(drv_data);
605 msg->actual_length += drv_data->len_in_bytes;
607 /* Move to next transfer */
608 msg->state = next_transfer(drv_data);
610 /* Schedule transfer tasklet */
611 tasklet_schedule(&drv_data->pump_transfers);
613 /* free the irq handler before next transfer */
614 dev_dbg(&drv_data->pdev->dev,
615 "disable dma channel irq%d\n",
617 dma_disable_irq(CH_SPI);
622 static void pump_transfers(unsigned long data)
624 struct driver_data *drv_data = (struct driver_data *)data;
625 struct spi_message *message = NULL;
626 struct spi_transfer *transfer = NULL;
627 struct spi_transfer *previous = NULL;
628 struct chip_data *chip = NULL;
630 u16 cr, dma_width, dma_config;
631 u32 tranf_success = 1;
633 /* Get current state information */
634 message = drv_data->cur_msg;
635 transfer = drv_data->cur_transfer;
636 chip = drv_data->cur_chip;
639 * if msg is error or done, report it back using complete() callback
642 /* Handle for abort */
643 if (message->state == ERROR_STATE) {
644 message->status = -EIO;
649 /* Handle end of message */
650 if (message->state == DONE_STATE) {
656 /* Delay if requested at end of transfer */
657 if (message->state == RUNNING_STATE) {
658 previous = list_entry(transfer->transfer_list.prev,
659 struct spi_transfer, transfer_list);
660 if (previous->delay_usecs)
661 udelay(previous->delay_usecs);
664 /* Setup the transfer state based on the type of transfer */
665 if (flush(drv_data) == 0) {
666 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
667 message->status = -EIO;
672 if (transfer->tx_buf != NULL) {
673 drv_data->tx = (void *)transfer->tx_buf;
674 drv_data->tx_end = drv_data->tx + transfer->len;
675 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
676 transfer->tx_buf, drv_data->tx_end);
681 if (transfer->rx_buf != NULL) {
682 drv_data->rx = transfer->rx_buf;
683 drv_data->rx_end = drv_data->rx + transfer->len;
684 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
685 transfer->rx_buf, drv_data->rx_end);
690 drv_data->rx_dma = transfer->rx_dma;
691 drv_data->tx_dma = transfer->tx_dma;
692 drv_data->len_in_bytes = transfer->len;
695 if (width == CFG_SPI_WORDSIZE16) {
696 drv_data->len = (transfer->len) >> 1;
698 drv_data->len = transfer->len;
700 drv_data->write = drv_data->tx ? chip->write : null_writer;
701 drv_data->read = drv_data->rx ? chip->read : null_reader;
702 drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
703 dev_dbg(&drv_data->pdev->dev,
704 "transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
705 drv_data->write, chip->write, null_writer);
707 /* speed and width has been set on per message */
708 message->state = RUNNING_STATE;
711 /* restore spi status for each spi transfer */
712 if (transfer->speed_hz) {
713 write_BAUD(hz_to_spi_baud(transfer->speed_hz));
715 write_BAUD(chip->baud);
717 write_FLAG(chip->flag);
719 dev_dbg(&drv_data->pdev->dev,
720 "now pumping a transfer: width is %d, len is %d\n",
721 width, transfer->len);
724 * Try to map dma buffer and do a dma transfer if
725 * successful use different way to r/w according to
726 * drv_data->cur_chip->enable_dma
728 if (drv_data->cur_chip->enable_dma && drv_data->len > 6) {
730 write_STAT(BIT_STAT_CLR);
732 clear_dma_irqstat(CH_SPI);
733 bfin_spi_disable(drv_data);
735 /* config dma channel */
736 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
737 if (width == CFG_SPI_WORDSIZE16) {
738 set_dma_x_count(CH_SPI, drv_data->len);
739 set_dma_x_modify(CH_SPI, 2);
740 dma_width = WDSIZE_16;
742 set_dma_x_count(CH_SPI, drv_data->len);
743 set_dma_x_modify(CH_SPI, 1);
744 dma_width = WDSIZE_8;
747 /* set transfer width,direction. And enable spi */
748 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
750 /* dirty hack for autobuffer DMA mode */
751 if (drv_data->tx_dma == 0xFFFF) {
752 dev_dbg(&drv_data->pdev->dev,
753 "doing autobuffer DMA out.\n");
755 /* no irq in autobuffer mode */
757 (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
758 set_dma_config(CH_SPI, dma_config);
759 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
761 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
762 (CFG_SPI_ENABLE << 14));
764 /* just return here, there can only be one transfer in this mode */
770 /* In dma mode, rx or tx must be NULL in one transfer */
771 if (drv_data->rx != NULL) {
772 /* set transfer mode, and enable SPI */
773 dev_dbg(&drv_data->pdev->dev, "doing DMA in.\n");
775 /* disable SPI before write to TDBR */
776 write_CTRL(cr & ~BIT_CTL_ENABLE);
778 /* clear tx reg soformer data is not shifted out */
781 set_dma_x_count(CH_SPI, drv_data->len);
784 dma_enable_irq(CH_SPI);
785 dma_config = (WNR | RESTART | dma_width | DI_EN);
786 set_dma_config(CH_SPI, dma_config);
787 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->rx);
791 CFG_SPI_DMAREAD | (width << 8) | (CFG_SPI_ENABLE <<
793 /* set transfer mode, and enable SPI */
795 } else if (drv_data->tx != NULL) {
796 dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
799 dma_enable_irq(CH_SPI);
800 dma_config = (RESTART | dma_width | DI_EN);
801 set_dma_config(CH_SPI, dma_config);
802 set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx);
805 write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) |
806 (CFG_SPI_ENABLE << 14));
810 /* IO mode write then read */
811 dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
813 write_STAT(BIT_STAT_CLR);
815 if (drv_data->tx != NULL && drv_data->rx != NULL) {
816 /* full duplex mode */
817 BUG_ON((drv_data->tx_end - drv_data->tx) !=
818 (drv_data->rx_end - drv_data->rx));
819 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
820 cr |= CFG_SPI_WRITE | (width << 8) |
821 (CFG_SPI_ENABLE << 14);
822 dev_dbg(&drv_data->pdev->dev,
823 "IO duplex: cr is 0x%x\n", cr);
828 drv_data->duplex(drv_data);
830 if (drv_data->tx != drv_data->tx_end)
832 } else if (drv_data->tx != NULL) {
833 /* write only half duplex */
834 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
835 cr |= CFG_SPI_WRITE | (width << 8) |
836 (CFG_SPI_ENABLE << 14);
837 dev_dbg(&drv_data->pdev->dev,
838 "IO write: cr is 0x%x\n", cr);
843 drv_data->write(drv_data);
845 if (drv_data->tx != drv_data->tx_end)
847 } else if (drv_data->rx != NULL) {
848 /* read only half duplex */
849 cr = (read_CTRL() & (~BIT_CTL_TIMOD));
850 cr |= CFG_SPI_READ | (width << 8) |
851 (CFG_SPI_ENABLE << 14);
852 dev_dbg(&drv_data->pdev->dev,
853 "IO read: cr is 0x%x\n", cr);
858 drv_data->read(drv_data);
859 if (drv_data->rx != drv_data->rx_end)
863 if (!tranf_success) {
864 dev_dbg(&drv_data->pdev->dev,
865 "IO write error!\n");
866 message->state = ERROR_STATE;
868 /* Update total byte transfered */
869 message->actual_length += drv_data->len;
871 /* Move to next transfer of this msg */
872 message->state = next_transfer(drv_data);
875 /* Schedule next transfer tasklet */
876 tasklet_schedule(&drv_data->pump_transfers);
881 /* pop a msg from queue and kick off real transfer */
882 static void pump_messages(struct work_struct *work)
884 struct driver_data *drv_data = container_of(work, struct driver_data, pump_messages);
887 /* Lock queue and check for queue work */
888 spin_lock_irqsave(&drv_data->lock, flags);
889 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
890 /* pumper kicked off but no work to do */
892 spin_unlock_irqrestore(&drv_data->lock, flags);
896 /* Make sure we are not already running a message */
897 if (drv_data->cur_msg) {
898 spin_unlock_irqrestore(&drv_data->lock, flags);
902 /* Extract head of queue */
903 drv_data->cur_msg = list_entry(drv_data->queue.next,
904 struct spi_message, queue);
905 list_del_init(&drv_data->cur_msg->queue);
907 /* Initial message state */
908 drv_data->cur_msg->state = START_STATE;
909 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
910 struct spi_transfer, transfer_list);
912 /* Setup the SSP using the per chip configuration */
913 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
914 restore_state(drv_data);
915 dev_dbg(&drv_data->pdev->dev,
916 "got a message to pump, state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
917 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
918 drv_data->cur_chip->ctl_reg);
920 dev_dbg(&drv_data->pdev->dev,
921 "the first transfer len is %d\n",
922 drv_data->cur_transfer->len);
924 /* Mark as busy and launch transfers */
925 tasklet_schedule(&drv_data->pump_transfers);
928 spin_unlock_irqrestore(&drv_data->lock, flags);
932 * got a msg to transfer, queue it in drv_data->queue.
933 * And kick off message pumper
935 static int transfer(struct spi_device *spi, struct spi_message *msg)
937 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
940 spin_lock_irqsave(&drv_data->lock, flags);
942 if (drv_data->run == QUEUE_STOPPED) {
943 spin_unlock_irqrestore(&drv_data->lock, flags);
947 msg->actual_length = 0;
948 msg->status = -EINPROGRESS;
949 msg->state = START_STATE;
951 dev_dbg(&spi->dev, "adding an msg in transfer() \n");
952 list_add_tail(&msg->queue, &drv_data->queue);
954 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
955 queue_work(drv_data->workqueue, &drv_data->pump_messages);
957 spin_unlock_irqrestore(&drv_data->lock, flags);
962 /* first setup for new devices */
963 static int setup(struct spi_device *spi)
965 struct bfin5xx_spi_chip *chip_info = NULL;
966 struct chip_data *chip;
967 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
970 /* Abort device setup if requested features are not supported */
971 if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
972 dev_err(&spi->dev, "requested mode not fully supported\n");
976 /* Zero (the default) here means 8 bits */
977 if (!spi->bits_per_word)
978 spi->bits_per_word = 8;
980 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
983 /* Only alloc (or use chip_info) on first setup */
984 chip = spi_get_ctldata(spi);
986 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
990 chip->enable_dma = 0;
991 chip_info = spi->controller_data;
994 /* chip_info isn't always needed */
996 chip->enable_dma = chip_info->enable_dma != 0
997 && drv_data->master_info->enable_dma;
998 chip->ctl_reg = chip_info->ctl_reg;
999 chip->bits_per_word = chip_info->bits_per_word;
1000 chip->cs_change_per_word = chip_info->cs_change_per_word;
1001 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
1004 /* translate common spi framework into our register */
1005 if (spi->mode & SPI_CPOL)
1006 chip->ctl_reg |= CPOL;
1007 if (spi->mode & SPI_CPHA)
1008 chip->ctl_reg |= CPHA;
1009 if (spi->mode & SPI_LSB_FIRST)
1010 chip->ctl_reg |= LSBF;
1011 /* we dont support running in slave mode (yet?) */
1012 chip->ctl_reg |= MSTR;
1015 * if any one SPI chip is registered and wants DMA, request the
1016 * DMA channel for it
1018 if (chip->enable_dma && !dma_requested) {
1019 /* register dma irq handler */
1020 if (request_dma(CH_SPI, "BF53x_SPI_DMA") < 0) {
1022 "Unable to request BlackFin SPI DMA channel\n");
1025 if (set_dma_callback(CH_SPI, (void *)dma_irq_handler, drv_data)
1027 dev_dbg(&spi->dev, "Unable to set dma callback\n");
1030 dma_disable_irq(CH_SPI);
1035 * Notice: for blackfin, the speed_hz is the value of register
1036 * SPI_BAUD, not the real baudrate
1038 chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1039 spi_flg = ~(1 << (spi->chip_select));
1040 chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
1041 chip->chip_select_num = spi->chip_select;
1043 switch (chip->bits_per_word) {
1046 chip->width = CFG_SPI_WORDSIZE8;
1047 chip->read = chip->cs_change_per_word ?
1048 u8_cs_chg_reader : u8_reader;
1049 chip->write = chip->cs_change_per_word ?
1050 u8_cs_chg_writer : u8_writer;
1051 chip->duplex = chip->cs_change_per_word ?
1052 u8_cs_chg_duplex : u8_duplex;
1057 chip->width = CFG_SPI_WORDSIZE16;
1058 chip->read = chip->cs_change_per_word ?
1059 u16_cs_chg_reader : u16_reader;
1060 chip->write = chip->cs_change_per_word ?
1061 u16_cs_chg_writer : u16_writer;
1062 chip->duplex = chip->cs_change_per_word ?
1063 u16_cs_chg_duplex : u16_duplex;
1067 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1068 chip->bits_per_word);
1073 dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1074 spi->modalias, chip->width, chip->enable_dma);
1075 dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1076 chip->ctl_reg, chip->flag);
1078 spi_set_ctldata(spi, chip);
1084 * callback for spi framework.
1085 * clean driver specific data
1087 static void cleanup(struct spi_device *spi)
1089 struct chip_data *chip = spi_get_ctldata(spi);
1094 static inline int init_queue(struct driver_data *drv_data)
1096 INIT_LIST_HEAD(&drv_data->queue);
1097 spin_lock_init(&drv_data->lock);
1099 drv_data->run = QUEUE_STOPPED;
1102 /* init transfer tasklet */
1103 tasklet_init(&drv_data->pump_transfers,
1104 pump_transfers, (unsigned long)drv_data);
1106 /* init messages workqueue */
1107 INIT_WORK(&drv_data->pump_messages, pump_messages);
1108 drv_data->workqueue =
1109 create_singlethread_workqueue(drv_data->master->dev.parent->bus_id);
1110 if (drv_data->workqueue == NULL)
1116 static inline int start_queue(struct driver_data *drv_data)
1118 unsigned long flags;
1120 spin_lock_irqsave(&drv_data->lock, flags);
1122 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1123 spin_unlock_irqrestore(&drv_data->lock, flags);
1127 drv_data->run = QUEUE_RUNNING;
1128 drv_data->cur_msg = NULL;
1129 drv_data->cur_transfer = NULL;
1130 drv_data->cur_chip = NULL;
1131 spin_unlock_irqrestore(&drv_data->lock, flags);
1133 queue_work(drv_data->workqueue, &drv_data->pump_messages);
1138 static inline int stop_queue(struct driver_data *drv_data)
1140 unsigned long flags;
1141 unsigned limit = 500;
1144 spin_lock_irqsave(&drv_data->lock, flags);
1147 * This is a bit lame, but is optimized for the common execution path.
1148 * A wait_queue on the drv_data->busy could be used, but then the common
1149 * execution path (pump_messages) would be required to call wake_up or
1150 * friends on every SPI message. Do this instead
1152 drv_data->run = QUEUE_STOPPED;
1153 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1154 spin_unlock_irqrestore(&drv_data->lock, flags);
1156 spin_lock_irqsave(&drv_data->lock, flags);
1159 if (!list_empty(&drv_data->queue) || drv_data->busy)
1162 spin_unlock_irqrestore(&drv_data->lock, flags);
1167 static inline int destroy_queue(struct driver_data *drv_data)
1171 status = stop_queue(drv_data);
1175 destroy_workqueue(drv_data->workqueue);
1180 static int __init bfin5xx_spi_probe(struct platform_device *pdev)
1182 struct device *dev = &pdev->dev;
1183 struct bfin5xx_spi_master *platform_info;
1184 struct spi_master *master;
1185 struct driver_data *drv_data = 0;
1188 platform_info = dev->platform_data;
1190 /* Allocate master with space for drv_data */
1191 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1193 dev_err(&pdev->dev, "can not alloc spi_master\n");
1196 drv_data = spi_master_get_devdata(master);
1197 drv_data->master = master;
1198 drv_data->master_info = platform_info;
1199 drv_data->pdev = pdev;
1201 master->bus_num = pdev->id;
1202 master->num_chipselect = platform_info->num_chipselect;
1203 master->cleanup = cleanup;
1204 master->setup = setup;
1205 master->transfer = transfer;
1207 /* Initial and start queue */
1208 status = init_queue(drv_data);
1210 dev_err(&pdev->dev, "problem initializing queue\n");
1211 goto out_error_queue_alloc;
1213 status = start_queue(drv_data);
1215 dev_err(&pdev->dev, "problem starting queue\n");
1216 goto out_error_queue_alloc;
1219 /* Register with the SPI framework */
1220 platform_set_drvdata(pdev, drv_data);
1221 status = spi_register_master(master);
1223 dev_err(&pdev->dev, "problem registering spi master\n");
1224 goto out_error_queue_alloc;
1226 dev_dbg(&pdev->dev, "controller probe successfully\n");
1229 out_error_queue_alloc:
1230 destroy_queue(drv_data);
1231 spi_master_put(master);
1235 /* stop hardware and remove the driver */
1236 static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
1238 struct driver_data *drv_data = platform_get_drvdata(pdev);
1244 /* Remove the queue */
1245 status = destroy_queue(drv_data);
1249 /* Disable the SSP at the peripheral and SOC level */
1250 bfin_spi_disable(drv_data);
1253 if (drv_data->master_info->enable_dma) {
1254 if (dma_channel_active(CH_SPI))
1258 /* Disconnect from the SPI framework */
1259 spi_unregister_master(drv_data->master);
1261 /* Prevent double remove */
1262 platform_set_drvdata(pdev, NULL);
1268 static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
1270 struct driver_data *drv_data = platform_get_drvdata(pdev);
1273 status = stop_queue(drv_data);
1278 bfin_spi_disable(drv_data);
1283 static int bfin5xx_spi_resume(struct platform_device *pdev)
1285 struct driver_data *drv_data = platform_get_drvdata(pdev);
1288 /* Enable the SPI interface */
1289 bfin_spi_enable(drv_data);
1291 /* Start the queue running */
1292 status = start_queue(drv_data);
1294 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1301 #define bfin5xx_spi_suspend NULL
1302 #define bfin5xx_spi_resume NULL
1303 #endif /* CONFIG_PM */
1305 MODULE_ALIAS("bfin-spi-master"); /* for platform bus hotplug */
1306 static struct platform_driver bfin5xx_spi_driver = {
1308 .name = "bfin-spi-master",
1309 .owner = THIS_MODULE,
1311 .suspend = bfin5xx_spi_suspend,
1312 .resume = bfin5xx_spi_resume,
1313 .remove = __devexit_p(bfin5xx_spi_remove),
1316 static int __init bfin5xx_spi_init(void)
1318 return platform_driver_probe(&bfin5xx_spi_driver, bfin5xx_spi_probe);
1320 module_init(bfin5xx_spi_init);
1322 static void __exit bfin5xx_spi_exit(void)
1324 platform_driver_unregister(&bfin5xx_spi_driver);
1326 module_exit(bfin5xx_spi_exit);