Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

Linux/drivers/spi/spi-bfin5xx.c

  1 /*
  2  * Blackfin On-Chip SPI Driver
  3  *
  4  * Copyright 2004-2010 Analog Devices Inc.
  5  *
  6  * Enter bugs at http://blackfin.uclinux.org/
  7  *
  8  * Licensed under the GPL-2 or later.
  9  */
 10 
 11 #include <linux/init.h>
 12 #include <linux/module.h>
 13 #include <linux/delay.h>
 14 #include <linux/device.h>
 15 #include <linux/gpio.h>
 16 #include <linux/slab.h>
 17 #include <linux/io.h>
 18 #include <linux/ioport.h>
 19 #include <linux/irq.h>
 20 #include <linux/errno.h>
 21 #include <linux/interrupt.h>
 22 #include <linux/platform_device.h>
 23 #include <linux/dma-mapping.h>
 24 #include <linux/spi/spi.h>
 25 #include <linux/workqueue.h>
 26 
 27 #include <asm/dma.h>
 28 #include <asm/portmux.h>
 29 #include <asm/bfin5xx_spi.h>
 30 #include <asm/cacheflush.h>
 31 
 32 #define DRV_NAME        "bfin-spi"
 33 #define DRV_AUTHOR      "Bryan Wu, Luke Yang"
 34 #define DRV_DESC        "Blackfin on-chip SPI Controller Driver"
 35 #define DRV_VERSION     "1.0"
 36 
 37 MODULE_AUTHOR(DRV_AUTHOR);
 38 MODULE_DESCRIPTION(DRV_DESC);
 39 MODULE_LICENSE("GPL");
 40 
 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 
 46 struct bfin_spi_master_data;
 47 
 48 struct bfin_spi_transfer_ops {
 49         void (*write) (struct bfin_spi_master_data *);
 50         void (*read) (struct bfin_spi_master_data *);
 51         void (*duplex) (struct bfin_spi_master_data *);
 52 };
 53 
 54 struct bfin_spi_master_data {
 55         /* Driver model hookup */
 56         struct platform_device *pdev;
 57 
 58         /* SPI framework hookup */
 59         struct spi_master *master;
 60 
 61         /* Regs base of SPI controller */
 62         struct bfin_spi_regs __iomem *regs;
 63 
 64         /* Pin request list */
 65         u16 *pin_req;
 66 
 67         /* BFIN hookup */
 68         struct bfin5xx_spi_master *master_info;
 69 
 70         /* Driver message queue */
 71         struct workqueue_struct *workqueue;
 72         struct work_struct pump_messages;
 73         spinlock_t lock;
 74         struct list_head queue;
 75         int busy;
 76         bool running;
 77 
 78         /* Message Transfer pump */
 79         struct tasklet_struct pump_transfers;
 80 
 81         /* Current message transfer state info */
 82         struct spi_message *cur_msg;
 83         struct spi_transfer *cur_transfer;
 84         struct bfin_spi_slave_data *cur_chip;
 85         size_t len_in_bytes;
 86         size_t len;
 87         void *tx;
 88         void *tx_end;
 89         void *rx;
 90         void *rx_end;
 91 
 92         /* DMA stuffs */
 93         int dma_channel;
 94         int dma_mapped;
 95         int dma_requested;
 96         dma_addr_t rx_dma;
 97         dma_addr_t tx_dma;
 98 
 99         int irq_requested;
100         int spi_irq;
101 
102         size_t rx_map_len;
103         size_t tx_map_len;
104         u8 n_bytes;
105         u16 ctrl_reg;
106         u16 flag_reg;
107 
108         int cs_change;
109         const struct bfin_spi_transfer_ops *ops;
110 };
111 
112 struct bfin_spi_slave_data {
113         u16 ctl_reg;
114         u16 baud;
115         u16 flag;
116 
117         u8 chip_select_num;
118         u8 enable_dma;
119         u16 cs_chg_udelay;      /* Some devices require > 255usec delay */
120         u32 cs_gpio;
121         u16 idle_tx_val;
122         u8 pio_interrupt;       /* use spi data irq */
123         const struct bfin_spi_transfer_ops *ops;
124 };
125 
126 static void bfin_spi_enable(struct bfin_spi_master_data *drv_data)
127 {
128         bfin_write_or(&drv_data->regs->ctl, BIT_CTL_ENABLE);
129 }
130 
131 static void bfin_spi_disable(struct bfin_spi_master_data *drv_data)
132 {
133         bfin_write_and(&drv_data->regs->ctl, ~BIT_CTL_ENABLE);
134 }
135 
136 /* Caculate the SPI_BAUD register value based on input HZ */
137 static u16 hz_to_spi_baud(u32 speed_hz)
138 {
139         u_long sclk = get_sclk();
140         u16 spi_baud = (sclk / (2 * speed_hz));
141 
142         if ((sclk % (2 * speed_hz)) > 0)
143                 spi_baud++;
144 
145         if (spi_baud < MIN_SPI_BAUD_VAL)
146                 spi_baud = MIN_SPI_BAUD_VAL;
147 
148         return spi_baud;
149 }
150 
151 static int bfin_spi_flush(struct bfin_spi_master_data *drv_data)
152 {
153         unsigned long limit = loops_per_jiffy << 1;
154 
155         /* wait for stop and clear stat */
156         while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_SPIF) && --limit)
157                 cpu_relax();
158 
159         bfin_write(&drv_data->regs->stat, BIT_STAT_CLR);
160 
161         return limit;
162 }
163 
164 /* Chip select operation functions for cs_change flag */
165 static void bfin_spi_cs_active(struct bfin_spi_master_data *drv_data, struct bfin_spi_slave_data *chip)
166 {
167         if (likely(chip->chip_select_num < MAX_CTRL_CS))
168                 bfin_write_and(&drv_data->regs->flg, ~chip->flag);
169         else
170                 gpio_set_value(chip->cs_gpio, 0);
171 }
172 
173 static void bfin_spi_cs_deactive(struct bfin_spi_master_data *drv_data,
174                                  struct bfin_spi_slave_data *chip)
175 {
176         if (likely(chip->chip_select_num < MAX_CTRL_CS))
177                 bfin_write_or(&drv_data->regs->flg, chip->flag);
178         else
179                 gpio_set_value(chip->cs_gpio, 1);
180 
181         /* Move delay here for consistency */
182         if (chip->cs_chg_udelay)
183                 udelay(chip->cs_chg_udelay);
184 }
185 
186 /* enable or disable the pin muxed by GPIO and SPI CS to work as SPI CS */
187 static inline void bfin_spi_cs_enable(struct bfin_spi_master_data *drv_data,
188                                       struct bfin_spi_slave_data *chip)
189 {
190         if (chip->chip_select_num < MAX_CTRL_CS)
191                 bfin_write_or(&drv_data->regs->flg, chip->flag >> 8);
192 }
193 
194 static inline void bfin_spi_cs_disable(struct bfin_spi_master_data *drv_data,
195                                        struct bfin_spi_slave_data *chip)
196 {
197         if (chip->chip_select_num < MAX_CTRL_CS)
198                 bfin_write_and(&drv_data->regs->flg, ~(chip->flag >> 8));
199 }
200 
201 /* stop controller and re-config current chip*/
202 static void bfin_spi_restore_state(struct bfin_spi_master_data *drv_data)
203 {
204         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
205 
206         /* Clear status and disable clock */
207         bfin_write(&drv_data->regs->stat, BIT_STAT_CLR);
208         bfin_spi_disable(drv_data);
209         dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
210 
211         SSYNC();
212 
213         /* Load the registers */
214         bfin_write(&drv_data->regs->ctl, chip->ctl_reg);
215         bfin_write(&drv_data->regs->baud, chip->baud);
216 
217         bfin_spi_enable(drv_data);
218         bfin_spi_cs_active(drv_data, chip);
219 }
220 
221 /* used to kick off transfer in rx mode and read unwanted RX data */
222 static inline void bfin_spi_dummy_read(struct bfin_spi_master_data *drv_data)
223 {
224         (void) bfin_read(&drv_data->regs->rdbr);
225 }
226 
227 static void bfin_spi_u8_writer(struct bfin_spi_master_data *drv_data)
228 {
229         /* clear RXS (we check for RXS inside the loop) */
230         bfin_spi_dummy_read(drv_data);
231 
232         while (drv_data->tx < drv_data->tx_end) {
233                 bfin_write(&drv_data->regs->tdbr, (*(u8 *) (drv_data->tx++)));
234                 /* wait until transfer finished.
235                    checking SPIF or TXS may not guarantee transfer completion */
236                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
237                         cpu_relax();
238                 /* discard RX data and clear RXS */
239                 bfin_spi_dummy_read(drv_data);
240         }
241 }
242 
243 static void bfin_spi_u8_reader(struct bfin_spi_master_data *drv_data)
244 {
245         u16 tx_val = drv_data->cur_chip->idle_tx_val;
246 
247         /* discard old RX data and clear RXS */
248         bfin_spi_dummy_read(drv_data);
249 
250         while (drv_data->rx < drv_data->rx_end) {
251                 bfin_write(&drv_data->regs->tdbr, tx_val);
252                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
253                         cpu_relax();
254                 *(u8 *) (drv_data->rx++) = bfin_read(&drv_data->regs->rdbr);
255         }
256 }
257 
258 static void bfin_spi_u8_duplex(struct bfin_spi_master_data *drv_data)
259 {
260         /* discard old RX data and clear RXS */
261         bfin_spi_dummy_read(drv_data);
262 
263         while (drv_data->rx < drv_data->rx_end) {
264                 bfin_write(&drv_data->regs->tdbr, (*(u8 *) (drv_data->tx++)));
265                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
266                         cpu_relax();
267                 *(u8 *) (drv_data->rx++) = bfin_read(&drv_data->regs->rdbr);
268         }
269 }
270 
271 static const struct bfin_spi_transfer_ops bfin_bfin_spi_transfer_ops_u8 = {
272         .write  = bfin_spi_u8_writer,
273         .read   = bfin_spi_u8_reader,
274         .duplex = bfin_spi_u8_duplex,
275 };
276 
277 static void bfin_spi_u16_writer(struct bfin_spi_master_data *drv_data)
278 {
279         /* clear RXS (we check for RXS inside the loop) */
280         bfin_spi_dummy_read(drv_data);
281 
282         while (drv_data->tx < drv_data->tx_end) {
283                 bfin_write(&drv_data->regs->tdbr, (*(u16 *) (drv_data->tx)));
284                 drv_data->tx += 2;
285                 /* wait until transfer finished.
286                    checking SPIF or TXS may not guarantee transfer completion */
287                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
288                         cpu_relax();
289                 /* discard RX data and clear RXS */
290                 bfin_spi_dummy_read(drv_data);
291         }
292 }
293 
294 static void bfin_spi_u16_reader(struct bfin_spi_master_data *drv_data)
295 {
296         u16 tx_val = drv_data->cur_chip->idle_tx_val;
297 
298         /* discard old RX data and clear RXS */
299         bfin_spi_dummy_read(drv_data);
300 
301         while (drv_data->rx < drv_data->rx_end) {
302                 bfin_write(&drv_data->regs->tdbr, tx_val);
303                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
304                         cpu_relax();
305                 *(u16 *) (drv_data->rx) = bfin_read(&drv_data->regs->rdbr);
306                 drv_data->rx += 2;
307         }
308 }
309 
310 static void bfin_spi_u16_duplex(struct bfin_spi_master_data *drv_data)
311 {
312         /* discard old RX data and clear RXS */
313         bfin_spi_dummy_read(drv_data);
314 
315         while (drv_data->rx < drv_data->rx_end) {
316                 bfin_write(&drv_data->regs->tdbr, (*(u16 *) (drv_data->tx)));
317                 drv_data->tx += 2;
318                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
319                         cpu_relax();
320                 *(u16 *) (drv_data->rx) = bfin_read(&drv_data->regs->rdbr);
321                 drv_data->rx += 2;
322         }
323 }
324 
325 static const struct bfin_spi_transfer_ops bfin_bfin_spi_transfer_ops_u16 = {
326         .write  = bfin_spi_u16_writer,
327         .read   = bfin_spi_u16_reader,
328         .duplex = bfin_spi_u16_duplex,
329 };
330 
331 /* test if there is more transfer to be done */
332 static void *bfin_spi_next_transfer(struct bfin_spi_master_data *drv_data)
333 {
334         struct spi_message *msg = drv_data->cur_msg;
335         struct spi_transfer *trans = drv_data->cur_transfer;
336 
337         /* Move to next transfer */
338         if (trans->transfer_list.next != &msg->transfers) {
339                 drv_data->cur_transfer =
340                     list_entry(trans->transfer_list.next,
341                                struct spi_transfer, transfer_list);
342                 return RUNNING_STATE;
343         } else
344                 return DONE_STATE;
345 }
346 
347 /*
348  * caller already set message->status;
349  * dma and pio irqs are blocked give finished message back
350  */
351 static void bfin_spi_giveback(struct bfin_spi_master_data *drv_data)
352 {
353         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
354         unsigned long flags;
355         struct spi_message *msg;
356 
357         spin_lock_irqsave(&drv_data->lock, flags);
358         msg = drv_data->cur_msg;
359         drv_data->cur_msg = NULL;
360         drv_data->cur_transfer = NULL;
361         drv_data->cur_chip = NULL;
362         queue_work(drv_data->workqueue, &drv_data->pump_messages);
363         spin_unlock_irqrestore(&drv_data->lock, flags);
364 
365         msg->state = NULL;
366 
367         if (!drv_data->cs_change)
368                 bfin_spi_cs_deactive(drv_data, chip);
369 
370         /* Not stop spi in autobuffer mode */
371         if (drv_data->tx_dma != 0xFFFF)
372                 bfin_spi_disable(drv_data);
373 
374         if (msg->complete)
375                 msg->complete(msg->context);
376 }
377 
378 /* spi data irq handler */
379 static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
380 {
381         struct bfin_spi_master_data *drv_data = dev_id;
382         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
383         struct spi_message *msg = drv_data->cur_msg;
384         int n_bytes = drv_data->n_bytes;
385         int loop = 0;
386 
387         /* wait until transfer finished. */
388         while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_RXS))
389                 cpu_relax();
390 
391         if ((drv_data->tx && drv_data->tx >= drv_data->tx_end) ||
392                 (drv_data->rx && drv_data->rx >= (drv_data->rx_end - n_bytes))) {
393                 /* last read */
394                 if (drv_data->rx) {
395                         dev_dbg(&drv_data->pdev->dev, "last read\n");
396                         if (!(n_bytes % 2)) {
397                                 u16 *buf = (u16 *)drv_data->rx;
398                                 for (loop = 0; loop < n_bytes / 2; loop++)
399                                         *buf++ = bfin_read(&drv_data->regs->rdbr);
400                         } else {
401                                 u8 *buf = (u8 *)drv_data->rx;
402                                 for (loop = 0; loop < n_bytes; loop++)
403                                         *buf++ = bfin_read(&drv_data->regs->rdbr);
404                         }
405                         drv_data->rx += n_bytes;
406                 }
407 
408                 msg->actual_length += drv_data->len_in_bytes;
409                 if (drv_data->cs_change)
410                         bfin_spi_cs_deactive(drv_data, chip);
411                 /* Move to next transfer */
412                 msg->state = bfin_spi_next_transfer(drv_data);
413 
414                 disable_irq_nosync(drv_data->spi_irq);
415 
416                 /* Schedule transfer tasklet */
417                 tasklet_schedule(&drv_data->pump_transfers);
418                 return IRQ_HANDLED;
419         }
420 
421         if (drv_data->rx && drv_data->tx) {
422                 /* duplex */
423                 dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n");
424                 if (!(n_bytes % 2)) {
425                         u16 *buf = (u16 *)drv_data->rx;
426                         u16 *buf2 = (u16 *)drv_data->tx;
427                         for (loop = 0; loop < n_bytes / 2; loop++) {
428                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
429                                 bfin_write(&drv_data->regs->tdbr, *buf2++);
430                         }
431                 } else {
432                         u8 *buf = (u8 *)drv_data->rx;
433                         u8 *buf2 = (u8 *)drv_data->tx;
434                         for (loop = 0; loop < n_bytes; loop++) {
435                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
436                                 bfin_write(&drv_data->regs->tdbr, *buf2++);
437                         }
438                 }
439         } else if (drv_data->rx) {
440                 /* read */
441                 dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n");
442                 if (!(n_bytes % 2)) {
443                         u16 *buf = (u16 *)drv_data->rx;
444                         for (loop = 0; loop < n_bytes / 2; loop++) {
445                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
446                                 bfin_write(&drv_data->regs->tdbr, chip->idle_tx_val);
447                         }
448                 } else {
449                         u8 *buf = (u8 *)drv_data->rx;
450                         for (loop = 0; loop < n_bytes; loop++) {
451                                 *buf++ = bfin_read(&drv_data->regs->rdbr);
452                                 bfin_write(&drv_data->regs->tdbr, chip->idle_tx_val);
453                         }
454                 }
455         } else if (drv_data->tx) {
456                 /* write */
457                 dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n");
458                 if (!(n_bytes % 2)) {
459                         u16 *buf = (u16 *)drv_data->tx;
460                         for (loop = 0; loop < n_bytes / 2; loop++) {
461                                 bfin_read(&drv_data->regs->rdbr);
462                                 bfin_write(&drv_data->regs->tdbr, *buf++);
463                         }
464                 } else {
465                         u8 *buf = (u8 *)drv_data->tx;
466                         for (loop = 0; loop < n_bytes; loop++) {
467                                 bfin_read(&drv_data->regs->rdbr);
468                                 bfin_write(&drv_data->regs->tdbr, *buf++);
469                         }
470                 }
471         }
472 
473         if (drv_data->tx)
474                 drv_data->tx += n_bytes;
475         if (drv_data->rx)
476                 drv_data->rx += n_bytes;
477 
478         return IRQ_HANDLED;
479 }
480 
481 static irqreturn_t bfin_spi_dma_irq_handler(int irq, void *dev_id)
482 {
483         struct bfin_spi_master_data *drv_data = dev_id;
484         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
485         struct spi_message *msg = drv_data->cur_msg;
486         unsigned long timeout;
487         unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel);
488         u16 spistat = bfin_read(&drv_data->regs->stat);
489 
490         dev_dbg(&drv_data->pdev->dev,
491                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
492                 dmastat, spistat);
493 
494         if (drv_data->rx != NULL) {
495                 u16 cr = bfin_read(&drv_data->regs->ctl);
496                 /* discard old RX data and clear RXS */
497                 bfin_spi_dummy_read(drv_data);
498                 bfin_write(&drv_data->regs->ctl, cr & ~BIT_CTL_ENABLE); /* Disable SPI */
499                 bfin_write(&drv_data->regs->ctl, cr & ~BIT_CTL_TIMOD); /* Restore State */
500                 bfin_write(&drv_data->regs->stat, BIT_STAT_CLR); /* Clear Status */
501         }
502 
503         clear_dma_irqstat(drv_data->dma_channel);
504 
505         /*
506          * wait for the last transaction shifted out.  HRM states:
507          * at this point there may still be data in the SPI DMA FIFO waiting
508          * to be transmitted ... software needs to poll TXS in the SPI_STAT
509          * register until it goes low for 2 successive reads
510          */
511         if (drv_data->tx != NULL) {
512                 while ((bfin_read(&drv_data->regs->stat) & BIT_STAT_TXS) ||
513                        (bfin_read(&drv_data->regs->stat) & BIT_STAT_TXS))
514                         cpu_relax();
515         }
516 
517         dev_dbg(&drv_data->pdev->dev,
518                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
519                 dmastat, bfin_read(&drv_data->regs->stat));
520 
521         timeout = jiffies + HZ;
522         while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_SPIF))
523                 if (!time_before(jiffies, timeout)) {
524                         dev_warn(&drv_data->pdev->dev, "timeout waiting for SPIF\n");
525                         break;
526                 } else
527                         cpu_relax();
528 
529         if ((dmastat & DMA_ERR) && (spistat & BIT_STAT_RBSY)) {
530                 msg->state = ERROR_STATE;
531                 dev_err(&drv_data->pdev->dev, "dma receive: fifo/buffer overflow\n");
532         } else {
533                 msg->actual_length += drv_data->len_in_bytes;
534 
535                 if (drv_data->cs_change)
536                         bfin_spi_cs_deactive(drv_data, chip);
537 
538                 /* Move to next transfer */
539                 msg->state = bfin_spi_next_transfer(drv_data);
540         }
541 
542         /* Schedule transfer tasklet */
543         tasklet_schedule(&drv_data->pump_transfers);
544 
545         /* free the irq handler before next transfer */
546         dev_dbg(&drv_data->pdev->dev,
547                 "disable dma channel irq%d\n",
548                 drv_data->dma_channel);
549         dma_disable_irq_nosync(drv_data->dma_channel);
550 
551         return IRQ_HANDLED;
552 }
553 
554 static void bfin_spi_pump_transfers(unsigned long data)
555 {
556         struct bfin_spi_master_data *drv_data = (struct bfin_spi_master_data *)data;
557         struct spi_message *message = NULL;
558         struct spi_transfer *transfer = NULL;
559         struct spi_transfer *previous = NULL;
560         struct bfin_spi_slave_data *chip = NULL;
561         unsigned int bits_per_word;
562         u16 cr, cr_width = 0, dma_width, dma_config;
563         u32 tranf_success = 1;
564         u8 full_duplex = 0;
565 
566         /* Get current state information */
567         message = drv_data->cur_msg;
568         transfer = drv_data->cur_transfer;
569         chip = drv_data->cur_chip;
570 
571         /*
572          * if msg is error or done, report it back using complete() callback
573          */
574 
575          /* Handle for abort */
576         if (message->state == ERROR_STATE) {
577                 dev_dbg(&drv_data->pdev->dev, "transfer: we've hit an error\n");
578                 message->status = -EIO;
579                 bfin_spi_giveback(drv_data);
580                 return;
581         }
582 
583         /* Handle end of message */
584         if (message->state == DONE_STATE) {
585                 dev_dbg(&drv_data->pdev->dev, "transfer: all done!\n");
586                 message->status = 0;
587                 bfin_spi_flush(drv_data);
588                 bfin_spi_giveback(drv_data);
589                 return;
590         }
591 
592         /* Delay if requested at end of transfer */
593         if (message->state == RUNNING_STATE) {
594                 dev_dbg(&drv_data->pdev->dev, "transfer: still running ...\n");
595                 previous = list_entry(transfer->transfer_list.prev,
596                                       struct spi_transfer, transfer_list);
597                 if (previous->delay_usecs)
598                         udelay(previous->delay_usecs);
599         }
600 
601         /* Flush any existing transfers that may be sitting in the hardware */
602         if (bfin_spi_flush(drv_data) == 0) {
603                 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
604                 message->status = -EIO;
605                 bfin_spi_giveback(drv_data);
606                 return;
607         }
608 
609         if (transfer->len == 0) {
610                 /* Move to next transfer of this msg */
611                 message->state = bfin_spi_next_transfer(drv_data);
612                 /* Schedule next transfer tasklet */
613                 tasklet_schedule(&drv_data->pump_transfers);
614                 return;
615         }
616 
617         if (transfer->tx_buf != NULL) {
618                 drv_data->tx = (void *)transfer->tx_buf;
619                 drv_data->tx_end = drv_data->tx + transfer->len;
620                 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
621                         transfer->tx_buf, drv_data->tx_end);
622         } else {
623                 drv_data->tx = NULL;
624         }
625 
626         if (transfer->rx_buf != NULL) {
627                 full_duplex = transfer->tx_buf != NULL;
628                 drv_data->rx = transfer->rx_buf;
629                 drv_data->rx_end = drv_data->rx + transfer->len;
630                 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
631                         transfer->rx_buf, drv_data->rx_end);
632         } else {
633                 drv_data->rx = NULL;
634         }
635 
636         drv_data->rx_dma = transfer->rx_dma;
637         drv_data->tx_dma = transfer->tx_dma;
638         drv_data->len_in_bytes = transfer->len;
639         drv_data->cs_change = transfer->cs_change;
640 
641         /* Bits per word setup */
642         bits_per_word = transfer->bits_per_word;
643         if (bits_per_word == 16) {
644                 drv_data->n_bytes = bits_per_word/8;
645                 drv_data->len = (transfer->len) >> 1;
646                 cr_width = BIT_CTL_WORDSIZE;
647                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u16;
648         } else if (bits_per_word == 8) {
649                 drv_data->n_bytes = bits_per_word/8;
650                 drv_data->len = transfer->len;
651                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
652         }
653         cr = bfin_read(&drv_data->regs->ctl) & ~(BIT_CTL_TIMOD | BIT_CTL_WORDSIZE);
654         cr |= cr_width;
655         bfin_write(&drv_data->regs->ctl, cr);
656 
657         dev_dbg(&drv_data->pdev->dev,
658                 "transfer: drv_data->ops is %p, chip->ops is %p, u8_ops is %p\n",
659                 drv_data->ops, chip->ops, &bfin_bfin_spi_transfer_ops_u8);
660 
661         message->state = RUNNING_STATE;
662         dma_config = 0;
663 
664         bfin_write(&drv_data->regs->baud, hz_to_spi_baud(transfer->speed_hz));
665 
666         bfin_write(&drv_data->regs->stat, BIT_STAT_CLR);
667         bfin_spi_cs_active(drv_data, chip);
668 
669         dev_dbg(&drv_data->pdev->dev,
670                 "now pumping a transfer: width is %d, len is %d\n",
671                 cr_width, transfer->len);
672 
673         /*
674          * Try to map dma buffer and do a dma transfer.  If successful use,
675          * different way to r/w according to the enable_dma settings and if
676          * we are not doing a full duplex transfer (since the hardware does
677          * not support full duplex DMA transfers).
678          */
679         if (!full_duplex && drv_data->cur_chip->enable_dma
680                                 && drv_data->len > 6) {
681 
682                 unsigned long dma_start_addr, flags;
683 
684                 disable_dma(drv_data->dma_channel);
685                 clear_dma_irqstat(drv_data->dma_channel);
686 
687                 /* config dma channel */
688                 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
689                 set_dma_x_count(drv_data->dma_channel, drv_data->len);
690                 if (cr_width == BIT_CTL_WORDSIZE) {
691                         set_dma_x_modify(drv_data->dma_channel, 2);
692                         dma_width = WDSIZE_16;
693                 } else {
694                         set_dma_x_modify(drv_data->dma_channel, 1);
695                         dma_width = WDSIZE_8;
696                 }
697 
698                 /* poll for SPI completion before start */
699                 while (!(bfin_read(&drv_data->regs->stat) & BIT_STAT_SPIF))
700                         cpu_relax();
701 
702                 /* dirty hack for autobuffer DMA mode */
703                 if (drv_data->tx_dma == 0xFFFF) {
704                         dev_dbg(&drv_data->pdev->dev,
705                                 "doing autobuffer DMA out.\n");
706 
707                         /* no irq in autobuffer mode */
708                         dma_config =
709                             (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
710                         set_dma_config(drv_data->dma_channel, dma_config);
711                         set_dma_start_addr(drv_data->dma_channel,
712                                         (unsigned long)drv_data->tx);
713                         enable_dma(drv_data->dma_channel);
714 
715                         /* start SPI transfer */
716                         bfin_write(&drv_data->regs->ctl, cr | BIT_CTL_TIMOD_DMA_TX);
717 
718                         /* just return here, there can only be one transfer
719                          * in this mode
720                          */
721                         message->status = 0;
722                         bfin_spi_giveback(drv_data);
723                         return;
724                 }
725 
726                 /* In dma mode, rx or tx must be NULL in one transfer */
727                 dma_config = (RESTART | dma_width | DI_EN);
728                 if (drv_data->rx != NULL) {
729                         /* set transfer mode, and enable SPI */
730                         dev_dbg(&drv_data->pdev->dev, "doing DMA in to %p (size %zx)\n",
731                                 drv_data->rx, drv_data->len_in_bytes);
732 
733                         /* invalidate caches, if needed */
734                         if (bfin_addr_dcacheable((unsigned long) drv_data->rx))
735                                 invalidate_dcache_range((unsigned long) drv_data->rx,
736                                                         (unsigned long) (drv_data->rx +
737                                                         drv_data->len_in_bytes));
738 
739                         dma_config |= WNR;
740                         dma_start_addr = (unsigned long)drv_data->rx;
741                         cr |= BIT_CTL_TIMOD_DMA_RX | BIT_CTL_SENDOPT;
742 
743                 } else if (drv_data->tx != NULL) {
744                         dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
745 
746                         /* flush caches, if needed */
747                         if (bfin_addr_dcacheable((unsigned long) drv_data->tx))
748                                 flush_dcache_range((unsigned long) drv_data->tx,
749                                                 (unsigned long) (drv_data->tx +
750                                                 drv_data->len_in_bytes));
751 
752                         dma_start_addr = (unsigned long)drv_data->tx;
753                         cr |= BIT_CTL_TIMOD_DMA_TX;
754 
755                 } else
756                         BUG();
757 
758                 /* oh man, here there be monsters ... and i dont mean the
759                  * fluffy cute ones from pixar, i mean the kind that'll eat
760                  * your data, kick your dog, and love it all.  do *not* try
761                  * and change these lines unless you (1) heavily test DMA
762                  * with SPI flashes on a loaded system (e.g. ping floods),
763                  * (2) know just how broken the DMA engine interaction with
764                  * the SPI peripheral is, and (3) have someone else to blame
765                  * when you screw it all up anyways.
766                  */
767                 set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
768                 set_dma_config(drv_data->dma_channel, dma_config);
769                 local_irq_save(flags);
770                 SSYNC();
771                 bfin_write(&drv_data->regs->ctl, cr);
772                 enable_dma(drv_data->dma_channel);
773                 dma_enable_irq(drv_data->dma_channel);
774                 local_irq_restore(flags);
775 
776                 return;
777         }
778 
779         /*
780          * We always use SPI_WRITE mode (transfer starts with TDBR write).
781          * SPI_READ mode (transfer starts with RDBR read) seems to have
782          * problems with setting up the output value in TDBR prior to the
783          * start of the transfer.
784          */
785         bfin_write(&drv_data->regs->ctl, cr | BIT_CTL_TXMOD);
786 
787         if (chip->pio_interrupt) {
788                 /* SPI irq should have been disabled by now */
789 
790                 /* discard old RX data and clear RXS */
791                 bfin_spi_dummy_read(drv_data);
792 
793                 /* start transfer */
794                 if (drv_data->tx == NULL)
795                         bfin_write(&drv_data->regs->tdbr, chip->idle_tx_val);
796                 else {
797                         int loop;
798                         if (bits_per_word == 16) {
799                                 u16 *buf = (u16 *)drv_data->tx;
800                                 for (loop = 0; loop < bits_per_word / 16;
801                                                 loop++) {
802                                         bfin_write(&drv_data->regs->tdbr, *buf++);
803                                 }
804                         } else if (bits_per_word == 8) {
805                                 u8 *buf = (u8 *)drv_data->tx;
806                                 for (loop = 0; loop < bits_per_word / 8; loop++)
807                                         bfin_write(&drv_data->regs->tdbr, *buf++);
808                         }
809 
810                         drv_data->tx += drv_data->n_bytes;
811                 }
812 
813                 /* once TDBR is empty, interrupt is triggered */
814                 enable_irq(drv_data->spi_irq);
815                 return;
816         }
817 
818         /* IO mode */
819         dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
820 
821         if (full_duplex) {
822                 /* full duplex mode */
823                 BUG_ON((drv_data->tx_end - drv_data->tx) !=
824                        (drv_data->rx_end - drv_data->rx));
825                 dev_dbg(&drv_data->pdev->dev,
826                         "IO duplex: cr is 0x%x\n", cr);
827 
828                 drv_data->ops->duplex(drv_data);
829 
830                 if (drv_data->tx != drv_data->tx_end)
831                         tranf_success = 0;
832         } else if (drv_data->tx != NULL) {
833                 /* write only half duplex */
834                 dev_dbg(&drv_data->pdev->dev,
835                         "IO write: cr is 0x%x\n", cr);
836 
837                 drv_data->ops->write(drv_data);
838 
839                 if (drv_data->tx != drv_data->tx_end)
840                         tranf_success = 0;
841         } else if (drv_data->rx != NULL) {
842                 /* read only half duplex */
843                 dev_dbg(&drv_data->pdev->dev,
844                         "IO read: cr is 0x%x\n", cr);
845 
846                 drv_data->ops->read(drv_data);
847                 if (drv_data->rx != drv_data->rx_end)
848                         tranf_success = 0;
849         }
850 
851         if (!tranf_success) {
852                 dev_dbg(&drv_data->pdev->dev,
853                         "IO write error!\n");
854                 message->state = ERROR_STATE;
855         } else {
856                 /* Update total byte transferred */
857                 message->actual_length += drv_data->len_in_bytes;
858                 /* Move to next transfer of this msg */
859                 message->state = bfin_spi_next_transfer(drv_data);
860                 if (drv_data->cs_change && message->state != DONE_STATE) {
861                         bfin_spi_flush(drv_data);
862                         bfin_spi_cs_deactive(drv_data, chip);
863                 }
864         }
865 
866         /* Schedule next transfer tasklet */
867         tasklet_schedule(&drv_data->pump_transfers);
868 }
869 
870 /* pop a msg from queue and kick off real transfer */
871 static void bfin_spi_pump_messages(struct work_struct *work)
872 {
873         struct bfin_spi_master_data *drv_data;
874         unsigned long flags;
875 
876         drv_data = container_of(work, struct bfin_spi_master_data, pump_messages);
877 
878         /* Lock queue and check for queue work */
879         spin_lock_irqsave(&drv_data->lock, flags);
880         if (list_empty(&drv_data->queue) || !drv_data->running) {
881                 /* pumper kicked off but no work to do */
882                 drv_data->busy = 0;
883                 spin_unlock_irqrestore(&drv_data->lock, flags);
884                 return;
885         }
886 
887         /* Make sure we are not already running a message */
888         if (drv_data->cur_msg) {
889                 spin_unlock_irqrestore(&drv_data->lock, flags);
890                 return;
891         }
892 
893         /* Extract head of queue */
894         drv_data->cur_msg = list_entry(drv_data->queue.next,
895                                        struct spi_message, queue);
896 
897         /* Setup the SSP using the per chip configuration */
898         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
899         bfin_spi_restore_state(drv_data);
900 
901         list_del_init(&drv_data->cur_msg->queue);
902 
903         /* Initial message state */
904         drv_data->cur_msg->state = START_STATE;
905         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
906                                             struct spi_transfer, transfer_list);
907 
908         dev_dbg(&drv_data->pdev->dev,
909                 "got a message to pump, state is set to: baud "
910                 "%d, flag 0x%x, ctl 0x%x\n",
911                 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
912                 drv_data->cur_chip->ctl_reg);
913 
914         dev_dbg(&drv_data->pdev->dev,
915                 "the first transfer len is %d\n",
916                 drv_data->cur_transfer->len);
917 
918         /* Mark as busy and launch transfers */
919         tasklet_schedule(&drv_data->pump_transfers);
920 
921         drv_data->busy = 1;
922         spin_unlock_irqrestore(&drv_data->lock, flags);
923 }
924 
925 /*
926  * got a msg to transfer, queue it in drv_data->queue.
927  * And kick off message pumper
928  */
929 static int bfin_spi_transfer(struct spi_device *spi, struct spi_message *msg)
930 {
931         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
932         unsigned long flags;
933 
934         spin_lock_irqsave(&drv_data->lock, flags);
935 
936         if (!drv_data->running) {
937                 spin_unlock_irqrestore(&drv_data->lock, flags);
938                 return -ESHUTDOWN;
939         }
940 
941         msg->actual_length = 0;
942         msg->status = -EINPROGRESS;
943         msg->state = START_STATE;
944 
945         dev_dbg(&spi->dev, "adding an msg in transfer() \n");
946         list_add_tail(&msg->queue, &drv_data->queue);
947 
948         if (drv_data->running && !drv_data->busy)
949                 queue_work(drv_data->workqueue, &drv_data->pump_messages);
950 
951         spin_unlock_irqrestore(&drv_data->lock, flags);
952 
953         return 0;
954 }
955 
956 #define MAX_SPI_SSEL    7
957 
958 static const u16 ssel[][MAX_SPI_SSEL] = {
959         {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
960         P_SPI0_SSEL4, P_SPI0_SSEL5,
961         P_SPI0_SSEL6, P_SPI0_SSEL7},
962 
963         {P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
964         P_SPI1_SSEL4, P_SPI1_SSEL5,
965         P_SPI1_SSEL6, P_SPI1_SSEL7},
966 
967         {P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
968         P_SPI2_SSEL4, P_SPI2_SSEL5,
969         P_SPI2_SSEL6, P_SPI2_SSEL7},
970 };
971 
972 /* setup for devices (may be called multiple times -- not just first setup) */
973 static int bfin_spi_setup(struct spi_device *spi)
974 {
975         struct bfin5xx_spi_chip *chip_info;
976         struct bfin_spi_slave_data *chip = NULL;
977         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
978         u16 bfin_ctl_reg;
979         int ret = -EINVAL;
980 
981         /* Only alloc (or use chip_info) on first setup */
982         chip_info = NULL;
983         chip = spi_get_ctldata(spi);
984         if (chip == NULL) {
985                 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
986                 if (!chip) {
987                         dev_err(&spi->dev, "cannot allocate chip data\n");
988                         ret = -ENOMEM;
989                         goto error;
990                 }
991 
992                 chip->enable_dma = 0;
993                 chip_info = spi->controller_data;
994         }
995 
996         /* Let people set non-standard bits directly */
997         bfin_ctl_reg = BIT_CTL_OPENDRAIN | BIT_CTL_EMISO |
998                 BIT_CTL_PSSE | BIT_CTL_GM | BIT_CTL_SZ;
999 
1000         /* chip_info isn't always needed */
1001         if (chip_info) {
1002                 /* Make sure people stop trying to set fields via ctl_reg
1003                  * when they should actually be using common SPI framework.
1004                  * Currently we let through: WOM EMISO PSSE GM SZ.
1005                  * Not sure if a user actually needs/uses any of these,
1006                  * but let's assume (for now) they do.
1007                  */
1008                 if (chip_info->ctl_reg & ~bfin_ctl_reg) {
1009                         dev_err(&spi->dev,
1010                                 "do not set bits in ctl_reg that the SPI framework manages\n");
1011                         goto error;
1012                 }
1013                 chip->enable_dma = chip_info->enable_dma != 0
1014                     && drv_data->master_info->enable_dma;
1015                 chip->ctl_reg = chip_info->ctl_reg;
1016                 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
1017                 chip->idle_tx_val = chip_info->idle_tx_val;
1018                 chip->pio_interrupt = chip_info->pio_interrupt;
1019         } else {
1020                 /* force a default base state */
1021                 chip->ctl_reg &= bfin_ctl_reg;
1022         }
1023 
1024         /* translate common spi framework into our register */
1025         if (spi->mode & SPI_CPOL)
1026                 chip->ctl_reg |= BIT_CTL_CPOL;
1027         if (spi->mode & SPI_CPHA)
1028                 chip->ctl_reg |= BIT_CTL_CPHA;
1029         if (spi->mode & SPI_LSB_FIRST)
1030                 chip->ctl_reg |= BIT_CTL_LSBF;
1031         /* we dont support running in slave mode (yet?) */
1032         chip->ctl_reg |= BIT_CTL_MASTER;
1033 
1034         /*
1035          * Notice: for blackfin, the speed_hz is the value of register
1036          * SPI_BAUD, not the real baudrate
1037          */
1038         chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1039         chip->chip_select_num = spi->chip_select;
1040         if (chip->chip_select_num < MAX_CTRL_CS) {
1041                 if (!(spi->mode & SPI_CPHA))
1042                         dev_warn(&spi->dev,
1043                                 "Warning: SPI CPHA not set: Slave Select not under software control!\n"
1044                                 "See Documentation/blackfin/bfin-spi-notes.txt\n");
1045 
1046                 chip->flag = (1 << spi->chip_select) << 8;
1047         } else
1048                 chip->cs_gpio = chip->chip_select_num - MAX_CTRL_CS;
1049 
1050         if (chip->enable_dma && chip->pio_interrupt) {
1051                 dev_err(&spi->dev,
1052                         "enable_dma is set, do not set pio_interrupt\n");
1053                 goto error;
1054         }
1055         /*
1056          * if any one SPI chip is registered and wants DMA, request the
1057          * DMA channel for it
1058          */
1059         if (chip->enable_dma && !drv_data->dma_requested) {
1060                 /* register dma irq handler */
1061                 ret = request_dma(drv_data->dma_channel, "BFIN_SPI_DMA");
1062                 if (ret) {
1063                         dev_err(&spi->dev,
1064                                 "Unable to request BlackFin SPI DMA channel\n");
1065                         goto error;
1066                 }
1067                 drv_data->dma_requested = 1;
1068 
1069                 ret = set_dma_callback(drv_data->dma_channel,
1070                         bfin_spi_dma_irq_handler, drv_data);
1071                 if (ret) {
1072                         dev_err(&spi->dev, "Unable to set dma callback\n");
1073                         goto error;
1074                 }
1075                 dma_disable_irq(drv_data->dma_channel);
1076         }
1077 
1078         if (chip->pio_interrupt && !drv_data->irq_requested) {
1079                 ret = request_irq(drv_data->spi_irq, bfin_spi_pio_irq_handler,
1080                         0, "BFIN_SPI", drv_data);
1081                 if (ret) {
1082                         dev_err(&spi->dev, "Unable to register spi IRQ\n");
1083                         goto error;
1084                 }
1085                 drv_data->irq_requested = 1;
1086                 /* we use write mode, spi irq has to be disabled here */
1087                 disable_irq(drv_data->spi_irq);
1088         }
1089 
1090         if (chip->chip_select_num >= MAX_CTRL_CS) {
1091                 /* Only request on first setup */
1092                 if (spi_get_ctldata(spi) == NULL) {
1093                         ret = gpio_request(chip->cs_gpio, spi->modalias);
1094                         if (ret) {
1095                                 dev_err(&spi->dev, "gpio_request() error\n");
1096                                 goto pin_error;
1097                         }
1098                         gpio_direction_output(chip->cs_gpio, 1);
1099                 }
1100         }
1101 
1102         dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1103                         spi->modalias, spi->bits_per_word, chip->enable_dma);
1104         dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1105                         chip->ctl_reg, chip->flag);
1106 
1107         spi_set_ctldata(spi, chip);
1108 
1109         dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
1110         if (chip->chip_select_num < MAX_CTRL_CS) {
1111                 ret = peripheral_request(ssel[spi->master->bus_num]
1112                                          [chip->chip_select_num-1], spi->modalias);
1113                 if (ret) {
1114                         dev_err(&spi->dev, "peripheral_request() error\n");
1115                         goto pin_error;
1116                 }
1117         }
1118 
1119         bfin_spi_cs_enable(drv_data, chip);
1120         bfin_spi_cs_deactive(drv_data, chip);
1121 
1122         return 0;
1123 
1124  pin_error:
1125         if (chip->chip_select_num >= MAX_CTRL_CS)
1126                 gpio_free(chip->cs_gpio);
1127         else
1128                 peripheral_free(ssel[spi->master->bus_num]
1129                         [chip->chip_select_num - 1]);
1130  error:
1131         if (chip) {
1132                 if (drv_data->dma_requested)
1133                         free_dma(drv_data->dma_channel);
1134                 drv_data->dma_requested = 0;
1135 
1136                 kfree(chip);
1137                 /* prevent free 'chip' twice */
1138                 spi_set_ctldata(spi, NULL);
1139         }
1140 
1141         return ret;
1142 }
1143 
1144 /*
1145  * callback for spi framework.
1146  * clean driver specific data
1147  */
1148 static void bfin_spi_cleanup(struct spi_device *spi)
1149 {
1150         struct bfin_spi_slave_data *chip = spi_get_ctldata(spi);
1151         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
1152 
1153         if (!chip)
1154                 return;
1155 
1156         if (chip->chip_select_num < MAX_CTRL_CS) {
1157                 peripheral_free(ssel[spi->master->bus_num]
1158                                         [chip->chip_select_num-1]);
1159                 bfin_spi_cs_disable(drv_data, chip);
1160         } else
1161                 gpio_free(chip->cs_gpio);
1162 
1163         kfree(chip);
1164         /* prevent free 'chip' twice */
1165         spi_set_ctldata(spi, NULL);
1166 }
1167 
1168 static int bfin_spi_init_queue(struct bfin_spi_master_data *drv_data)
1169 {
1170         INIT_LIST_HEAD(&drv_data->queue);
1171         spin_lock_init(&drv_data->lock);
1172 
1173         drv_data->running = false;
1174         drv_data->busy = 0;
1175 
1176         /* init transfer tasklet */
1177         tasklet_init(&drv_data->pump_transfers,
1178                      bfin_spi_pump_transfers, (unsigned long)drv_data);
1179 
1180         /* init messages workqueue */
1181         INIT_WORK(&drv_data->pump_messages, bfin_spi_pump_messages);
1182         drv_data->workqueue = create_singlethread_workqueue(
1183                                 dev_name(drv_data->master->dev.parent));
1184         if (drv_data->workqueue == NULL)
1185                 return -EBUSY;
1186 
1187         return 0;
1188 }
1189 
1190 static int bfin_spi_start_queue(struct bfin_spi_master_data *drv_data)
1191 {
1192         unsigned long flags;
1193 
1194         spin_lock_irqsave(&drv_data->lock, flags);
1195 
1196         if (drv_data->running || drv_data->busy) {
1197                 spin_unlock_irqrestore(&drv_data->lock, flags);
1198                 return -EBUSY;
1199         }
1200 
1201         drv_data->running = true;
1202         drv_data->cur_msg = NULL;
1203         drv_data->cur_transfer = NULL;
1204         drv_data->cur_chip = NULL;
1205         spin_unlock_irqrestore(&drv_data->lock, flags);
1206 
1207         queue_work(drv_data->workqueue, &drv_data->pump_messages);
1208 
1209         return 0;
1210 }
1211 
1212 static int bfin_spi_stop_queue(struct bfin_spi_master_data *drv_data)
1213 {
1214         unsigned long flags;
1215         unsigned limit = 500;
1216         int status = 0;
1217 
1218         spin_lock_irqsave(&drv_data->lock, flags);
1219 
1220         /*
1221          * This is a bit lame, but is optimized for the common execution path.
1222          * A wait_queue on the drv_data->busy could be used, but then the common
1223          * execution path (pump_messages) would be required to call wake_up or
1224          * friends on every SPI message. Do this instead
1225          */
1226         drv_data->running = false;
1227         while ((!list_empty(&drv_data->queue) || drv_data->busy) && limit--) {
1228                 spin_unlock_irqrestore(&drv_data->lock, flags);
1229                 msleep(10);
1230                 spin_lock_irqsave(&drv_data->lock, flags);
1231         }
1232 
1233         if (!list_empty(&drv_data->queue) || drv_data->busy)
1234                 status = -EBUSY;
1235 
1236         spin_unlock_irqrestore(&drv_data->lock, flags);
1237 
1238         return status;
1239 }
1240 
1241 static int bfin_spi_destroy_queue(struct bfin_spi_master_data *drv_data)
1242 {
1243         int status;
1244 
1245         status = bfin_spi_stop_queue(drv_data);
1246         if (status != 0)
1247                 return status;
1248 
1249         destroy_workqueue(drv_data->workqueue);
1250 
1251         return 0;
1252 }
1253 
1254 static int bfin_spi_probe(struct platform_device *pdev)
1255 {
1256         struct device *dev = &pdev->dev;
1257         struct bfin5xx_spi_master *platform_info;
1258         struct spi_master *master;
1259         struct bfin_spi_master_data *drv_data;
1260         struct resource *res;
1261         int status = 0;
1262 
1263         platform_info = dev_get_platdata(dev);
1264 
1265         /* Allocate master with space for drv_data */
1266         master = spi_alloc_master(dev, sizeof(*drv_data));
1267         if (!master) {
1268                 dev_err(&pdev->dev, "can not alloc spi_master\n");
1269                 return -ENOMEM;
1270         }
1271 
1272         drv_data = spi_master_get_devdata(master);
1273         drv_data->master = master;
1274         drv_data->master_info = platform_info;
1275         drv_data->pdev = pdev;
1276         drv_data->pin_req = platform_info->pin_req;
1277 
1278         /* the spi->mode bits supported by this driver: */
1279         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
1280         master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
1281         master->bus_num = pdev->id;
1282         master->num_chipselect = platform_info->num_chipselect;
1283         master->cleanup = bfin_spi_cleanup;
1284         master->setup = bfin_spi_setup;
1285         master->transfer = bfin_spi_transfer;
1286 
1287         /* Find and map our resources */
1288         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1289         if (res == NULL) {
1290                 dev_err(dev, "Cannot get IORESOURCE_MEM\n");
1291                 status = -ENOENT;
1292                 goto out_error_get_res;
1293         }
1294 
1295         drv_data->regs = ioremap(res->start, resource_size(res));
1296         if (drv_data->regs == NULL) {
1297                 dev_err(dev, "Cannot map IO\n");
1298                 status = -ENXIO;
1299                 goto out_error_ioremap;
1300         }
1301 
1302         res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1303         if (res == NULL) {
1304                 dev_err(dev, "No DMA channel specified\n");
1305                 status = -ENOENT;
1306                 goto out_error_free_io;
1307         }
1308         drv_data->dma_channel = res->start;
1309 
1310         drv_data->spi_irq = platform_get_irq(pdev, 0);
1311         if (drv_data->spi_irq < 0) {
1312                 dev_err(dev, "No spi pio irq specified\n");
1313                 status = -ENOENT;
1314                 goto out_error_free_io;
1315         }
1316 
1317         /* Initial and start queue */
1318         status = bfin_spi_init_queue(drv_data);
1319         if (status != 0) {
1320                 dev_err(dev, "problem initializing queue\n");
1321                 goto out_error_queue_alloc;
1322         }
1323 
1324         status = bfin_spi_start_queue(drv_data);
1325         if (status != 0) {
1326                 dev_err(dev, "problem starting queue\n");
1327                 goto out_error_queue_alloc;
1328         }
1329 
1330         status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
1331         if (status != 0) {
1332                 dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
1333                 goto out_error_queue_alloc;
1334         }
1335 
1336         /* Reset SPI registers. If these registers were used by the boot loader,
1337          * the sky may fall on your head if you enable the dma controller.
1338          */
1339         bfin_write(&drv_data->regs->ctl, BIT_CTL_CPHA | BIT_CTL_MASTER);
1340         bfin_write(&drv_data->regs->flg, 0xFF00);
1341 
1342         /* Register with the SPI framework */
1343         platform_set_drvdata(pdev, drv_data);
1344         status = spi_register_master(master);
1345         if (status != 0) {
1346                 dev_err(dev, "problem registering spi master\n");
1347                 goto out_error_queue_alloc;
1348         }
1349 
1350         dev_info(dev, "%s, Version %s, regs@%p, dma channel@%d\n",
1351                 DRV_DESC, DRV_VERSION, drv_data->regs,
1352                 drv_data->dma_channel);
1353         return status;
1354 
1355 out_error_queue_alloc:
1356         bfin_spi_destroy_queue(drv_data);
1357 out_error_free_io:
1358         iounmap(drv_data->regs);
1359 out_error_ioremap:
1360 out_error_get_res:
1361         spi_master_put(master);
1362 
1363         return status;
1364 }
1365 
1366 /* stop hardware and remove the driver */
1367 static int bfin_spi_remove(struct platform_device *pdev)
1368 {
1369         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1370         int status = 0;
1371 
1372         if (!drv_data)
1373                 return 0;
1374 
1375         /* Remove the queue */
1376         status = bfin_spi_destroy_queue(drv_data);
1377         if (status != 0)
1378                 return status;
1379 
1380         /* Disable the SSP at the peripheral and SOC level */
1381         bfin_spi_disable(drv_data);
1382 
1383         /* Release DMA */
1384         if (drv_data->master_info->enable_dma) {
1385                 if (dma_channel_active(drv_data->dma_channel))
1386                         free_dma(drv_data->dma_channel);
1387         }
1388 
1389         if (drv_data->irq_requested) {
1390                 free_irq(drv_data->spi_irq, drv_data);
1391                 drv_data->irq_requested = 0;
1392         }
1393 
1394         /* Disconnect from the SPI framework */
1395         spi_unregister_master(drv_data->master);
1396 
1397         peripheral_free_list(drv_data->pin_req);
1398 
1399         return 0;
1400 }
1401 
1402 #ifdef CONFIG_PM_SLEEP
1403 static int bfin_spi_suspend(struct device *dev)
1404 {
1405         struct bfin_spi_master_data *drv_data = dev_get_drvdata(dev);
1406         int status = 0;
1407 
1408         status = bfin_spi_stop_queue(drv_data);
1409         if (status != 0)
1410                 return status;
1411 
1412         drv_data->ctrl_reg = bfin_read(&drv_data->regs->ctl);
1413         drv_data->flag_reg = bfin_read(&drv_data->regs->flg);
1414 
1415         /*
1416          * reset SPI_CTL and SPI_FLG registers
1417          */
1418         bfin_write(&drv_data->regs->ctl, BIT_CTL_CPHA | BIT_CTL_MASTER);
1419         bfin_write(&drv_data->regs->flg, 0xFF00);
1420 
1421         return 0;
1422 }
1423 
1424 static int bfin_spi_resume(struct device *dev)
1425 {
1426         struct bfin_spi_master_data *drv_data = dev_get_drvdata(dev);
1427         int status = 0;
1428 
1429         bfin_write(&drv_data->regs->ctl, drv_data->ctrl_reg);
1430         bfin_write(&drv_data->regs->flg, drv_data->flag_reg);
1431 
1432         /* Start the queue running */
1433         status = bfin_spi_start_queue(drv_data);
1434         if (status != 0) {
1435                 dev_err(dev, "problem starting queue (%d)\n", status);
1436                 return status;
1437         }
1438 
1439         return 0;
1440 }
1441 
1442 static SIMPLE_DEV_PM_OPS(bfin_spi_pm_ops, bfin_spi_suspend, bfin_spi_resume);
1443 
1444 #define BFIN_SPI_PM_OPS         (&bfin_spi_pm_ops)
1445 #else
1446 #define BFIN_SPI_PM_OPS         NULL
1447 #endif
1448 
1449 MODULE_ALIAS("platform:bfin-spi");
1450 static struct platform_driver bfin_spi_driver = {
1451         .driver = {
1452                 .name   = DRV_NAME,
1453                 .pm     = BFIN_SPI_PM_OPS,
1454         },
1455         .probe          = bfin_spi_probe,
1456         .remove         = bfin_spi_remove,
1457 };
1458 
1459 static int __init bfin_spi_init(void)
1460 {
1461         return platform_driver_register(&bfin_spi_driver);
1462 }
1463 subsys_initcall(bfin_spi_init);
1464 
1465 static void __exit bfin_spi_exit(void)
1466 {
1467         platform_driver_unregister(&bfin_spi_driver);
1468 }
1469 module_exit(bfin_spi_exit);
1470 

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