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Blackfin: ints-priority: clean up some local vars
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / spi / dw_spi.c
blob871e337c917fe7313621e651be0da62891545b05
1 /*
2 * dw_spi.c - Designware SPI core controller driver (refer pxa2xx_spi.c)
3 *
4 * Copyright (c) 2009, Intel Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #include <linux/dma-mapping.h>
21 #include <linux/interrupt.h>
22 #include <linux/highmem.h>
23 #include <linux/delay.h>
24 #include <linux/slab.h>
25 #include <linux/spi/spi.h>
26
27 #include "dw_spi.h"
28
29 #ifdef CONFIG_DEBUG_FS
30 #include <linux/debugfs.h>
31 #endif
32
33 #define START_STATE ((void *)0)
34 #define RUNNING_STATE ((void *)1)
35 #define DONE_STATE ((void *)2)
36 #define ERROR_STATE ((void *)-1)
37
38 #define QUEUE_RUNNING 0
39 #define QUEUE_STOPPED 1
40
41 #define MRST_SPI_DEASSERT 0
42 #define MRST_SPI_ASSERT 1
43
44 /* Slave spi_dev related */
45 struct chip_data {
46 u16 cr0;
47 u8 cs; /* chip select pin */
48 u8 n_bytes; /* current is a 1/2/4 byte op */
49 u8 tmode; /* TR/TO/RO/EEPROM */
50 u8 type; /* SPI/SSP/MicroWire */
51
52 u8 poll_mode; /* 1 means use poll mode */
53
54 u32 dma_width;
55 u32 rx_threshold;
56 u32 tx_threshold;
57 u8 enable_dma;
58 u8 bits_per_word;
59 u16 clk_div; /* baud rate divider */
60 u32 speed_hz; /* baud rate */
61 int (*write)(struct dw_spi *dws);
62 int (*read)(struct dw_spi *dws);
63 void (*cs_control)(u32 command);
64 };
65
66 #ifdef CONFIG_DEBUG_FS
67 static int spi_show_regs_open(struct inode *inode, struct file *file)
68 {
69 file->private_data = inode->i_private;
70 return 0;
71 }
72
73 #define SPI_REGS_BUFSIZE 1024
74 static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
75 size_t count, loff_t *ppos)
76 {
77 struct dw_spi *dws;
78 char *buf;
79 u32 len = 0;
80 ssize_t ret;
81
82 dws = file->private_data;
83
84 buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
85 if (!buf)
86 return 0;
87
88 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
89 "MRST SPI0 registers:\n");
90 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
91 "=================================\n");
92 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
93 "CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
94 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
95 "CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
96 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
97 "SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
98 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
99 "SER: \t\t0x%08x\n", dw_readl(dws, ser));
100 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
101 "BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
102 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
103 "TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
104 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
105 "RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
106 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
107 "TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
108 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
109 "RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
110 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
111 "SR: \t\t0x%08x\n", dw_readl(dws, sr));
112 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
113 "IMR: \t\t0x%08x\n", dw_readl(dws, imr));
114 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
115 "ISR: \t\t0x%08x\n", dw_readl(dws, isr));
116 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
117 "DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
118 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
119 "DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
120 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
121 "DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
122 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
123 "=================================\n");
124
125 ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
126 kfree(buf);
127 return ret;
128 }
129
130 static const struct file_operations mrst_spi_regs_ops = {
131 .owner = THIS_MODULE,
132 .open = spi_show_regs_open,
133 .read = spi_show_regs,
134 .llseek = default_llseek,
135 };
136
137 static int mrst_spi_debugfs_init(struct dw_spi *dws)
138 {
139 dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
140 if (!dws->debugfs)
141 return -ENOMEM;
142
143 debugfs_create_file("registers", S_IFREG | S_IRUGO,
144 dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
145 return 0;
146 }
147
148 static void mrst_spi_debugfs_remove(struct dw_spi *dws)
149 {
150 if (dws->debugfs)
151 debugfs_remove_recursive(dws->debugfs);
152 }
153
154 #else
155 static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
156 {
157 return 0;
158 }
159
160 static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
161 {
162 }
163 #endif /* CONFIG_DEBUG_FS */
164
165 static void wait_till_not_busy(struct dw_spi *dws)
166 {
167 unsigned long end = jiffies + 1 + usecs_to_jiffies(5000);
168
169 while (time_before(jiffies, end)) {
170 if (!(dw_readw(dws, sr) & SR_BUSY))
171 return;
172 cpu_relax();
173 }
174 dev_err(&dws->master->dev,
175 "DW SPI: Status keeps busy for 5000us after a read/write!\n");
176 }
177
178 static void flush(struct dw_spi *dws)
179 {
180 while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) {
181 dw_readw(dws, dr);
182 cpu_relax();
183 }
184
185 wait_till_not_busy(dws);
186 }
187
188 static int null_writer(struct dw_spi *dws)
189 {
190 u8 n_bytes = dws->n_bytes;
191
192 if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
193 || (dws->tx == dws->tx_end))
194 return 0;
195 dw_writew(dws, dr, 0);
196 dws->tx += n_bytes;
197
198 wait_till_not_busy(dws);
199 return 1;
200 }
201
202 static int null_reader(struct dw_spi *dws)
203 {
204 u8 n_bytes = dws->n_bytes;
205
206 while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
207 && (dws->rx < dws->rx_end)) {
208 dw_readw(dws, dr);
209 dws->rx += n_bytes;
210 }
211 wait_till_not_busy(dws);
212 return dws->rx == dws->rx_end;
213 }
214
215 static int u8_writer(struct dw_spi *dws)
216 {
217 if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
218 || (dws->tx == dws->tx_end))
219 return 0;
220
221 dw_writew(dws, dr, *(u8 *)(dws->tx));
222 ++dws->tx;
223
224 wait_till_not_busy(dws);
225 return 1;
226 }
227
228 static int u8_reader(struct dw_spi *dws)
229 {
230 while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
231 && (dws->rx < dws->rx_end)) {
232 *(u8 *)(dws->rx) = dw_readw(dws, dr);
233 ++dws->rx;
234 }
235
236 wait_till_not_busy(dws);
237 return dws->rx == dws->rx_end;
238 }
239
240 static int u16_writer(struct dw_spi *dws)
241 {
242 if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
243 || (dws->tx == dws->tx_end))
244 return 0;
245
246 dw_writew(dws, dr, *(u16 *)(dws->tx));
247 dws->tx += 2;
248
249 wait_till_not_busy(dws);
250 return 1;
251 }
252
253 static int u16_reader(struct dw_spi *dws)
254 {
255 u16 temp;
256
257 while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
258 && (dws->rx < dws->rx_end)) {
259 temp = dw_readw(dws, dr);
260 *(u16 *)(dws->rx) = temp;
261 dws->rx += 2;
262 }
263
264 wait_till_not_busy(dws);
265 return dws->rx == dws->rx_end;
266 }
267
268 static void *next_transfer(struct dw_spi *dws)
269 {
270 struct spi_message *msg = dws->cur_msg;
271 struct spi_transfer *trans = dws->cur_transfer;
272
273 /* Move to next transfer */
274 if (trans->transfer_list.next != &msg->transfers) {
275 dws->cur_transfer =
276 list_entry(trans->transfer_list.next,
277 struct spi_transfer,
278 transfer_list);
279 return RUNNING_STATE;
280 } else
281 return DONE_STATE;
282 }
283
284 /*
285 * Note: first step is the protocol driver prepares
286 * a dma-capable memory, and this func just need translate
287 * the virt addr to physical
288 */
289 static int map_dma_buffers(struct dw_spi *dws)
290 {
291 if (!dws->cur_msg->is_dma_mapped
292 || !dws->dma_inited
293 || !dws->cur_chip->enable_dma
294 || !dws->dma_ops)
295 return 0;
296
297 if (dws->cur_transfer->tx_dma)
298 dws->tx_dma = dws->cur_transfer->tx_dma;
299
300 if (dws->cur_transfer->rx_dma)
301 dws->rx_dma = dws->cur_transfer->rx_dma;
302
303 return 1;
304 }
305
306 /* Caller already set message->status; dma and pio irqs are blocked */
307 static void giveback(struct dw_spi *dws)
308 {
309 struct spi_transfer *last_transfer;
310 unsigned long flags;
311 struct spi_message *msg;
312
313 spin_lock_irqsave(&dws->lock, flags);
314 msg = dws->cur_msg;
315 dws->cur_msg = NULL;
316 dws->cur_transfer = NULL;
317 dws->prev_chip = dws->cur_chip;
318 dws->cur_chip = NULL;
319 dws->dma_mapped = 0;
320 queue_work(dws->workqueue, &dws->pump_messages);
321 spin_unlock_irqrestore(&dws->lock, flags);
322
323 last_transfer = list_entry(msg->transfers.prev,
324 struct spi_transfer,
325 transfer_list);
326
327 if (!last_transfer->cs_change && dws->cs_control)
328 dws->cs_control(MRST_SPI_DEASSERT);
329
330 msg->state = NULL;
331 if (msg->complete)
332 msg->complete(msg->context);
333 }
334
335 static void int_error_stop(struct dw_spi *dws, const char *msg)
336 {
337 /* Stop and reset hw */
338 flush(dws);
339 spi_enable_chip(dws, 0);
340
341 dev_err(&dws->master->dev, "%s\n", msg);
342 dws->cur_msg->state = ERROR_STATE;
343 tasklet_schedule(&dws->pump_transfers);
344 }
345
346 void dw_spi_xfer_done(struct dw_spi *dws)
347 {
348 /* Update total byte transferred return count actual bytes read */
349 dws->cur_msg->actual_length += dws->len;
350
351 /* Move to next transfer */
352 dws->cur_msg->state = next_transfer(dws);
353
354 /* Handle end of message */
355 if (dws->cur_msg->state == DONE_STATE) {
356 dws->cur_msg->status = 0;
357 giveback(dws);
358 } else
359 tasklet_schedule(&dws->pump_transfers);
360 }
361 EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
362
363 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
364 {
365 u16 irq_status, irq_mask = 0x3f;
366 u32 int_level = dws->fifo_len / 2;
367 u32 left;
368
369 irq_status = dw_readw(dws, isr) & irq_mask;
370 /* Error handling */
371 if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
372 dw_readw(dws, txoicr);
373 dw_readw(dws, rxoicr);
374 dw_readw(dws, rxuicr);
375 int_error_stop(dws, "interrupt_transfer: fifo overrun");
376 return IRQ_HANDLED;
377 }
378
379 if (irq_status & SPI_INT_TXEI) {
380 spi_mask_intr(dws, SPI_INT_TXEI);
381
382 left = (dws->tx_end - dws->tx) / dws->n_bytes;
383 left = (left > int_level) ? int_level : left;
384
385 while (left--)
386 dws->write(dws);
387 dws->read(dws);
388
389 /* Re-enable the IRQ if there is still data left to tx */
390 if (dws->tx_end > dws->tx)
391 spi_umask_intr(dws, SPI_INT_TXEI);
392 else
393 dw_spi_xfer_done(dws);
394 }
395
396 return IRQ_HANDLED;
397 }
398
399 static irqreturn_t dw_spi_irq(int irq, void *dev_id)
400 {
401 struct dw_spi *dws = dev_id;
402 u16 irq_status, irq_mask = 0x3f;
403
404 irq_status = dw_readw(dws, isr) & irq_mask;
405 if (!irq_status)
406 return IRQ_NONE;
407
408 if (!dws->cur_msg) {
409 spi_mask_intr(dws, SPI_INT_TXEI);
410 /* Never fail */
411 return IRQ_HANDLED;
412 }
413
414 return dws->transfer_handler(dws);
415 }
416
417 /* Must be called inside pump_transfers() */
418 static void poll_transfer(struct dw_spi *dws)
419 {
420 while (dws->write(dws))
421 dws->read(dws);
422 /*
423 * There is a possibility that the last word of a transaction
424 * will be lost if data is not ready. Re-read to solve this issue.
425 */
426 dws->read(dws);
427
428 dw_spi_xfer_done(dws);
429 }
430
431 static void pump_transfers(unsigned long data)
432 {
433 struct dw_spi *dws = (struct dw_spi *)data;
434 struct spi_message *message = NULL;
435 struct spi_transfer *transfer = NULL;
436 struct spi_transfer *previous = NULL;
437 struct spi_device *spi = NULL;
438 struct chip_data *chip = NULL;
439 u8 bits = 0;
440 u8 imask = 0;
441 u8 cs_change = 0;
442 u16 txint_level = 0;
443 u16 clk_div = 0;
444 u32 speed = 0;
445 u32 cr0 = 0;
446
447 /* Get current state information */
448 message = dws->cur_msg;
449 transfer = dws->cur_transfer;
450 chip = dws->cur_chip;
451 spi = message->spi;
452
453 if (unlikely(!chip->clk_div))
454 chip->clk_div = dws->max_freq / chip->speed_hz;
455
456 if (message->state == ERROR_STATE) {
457 message->status = -EIO;
458 goto early_exit;
459 }
460
461 /* Handle end of message */
462 if (message->state == DONE_STATE) {
463 message->status = 0;
464 goto early_exit;
465 }
466
467 /* Delay if requested at end of transfer*/
468 if (message->state == RUNNING_STATE) {
469 previous = list_entry(transfer->transfer_list.prev,
470 struct spi_transfer,
471 transfer_list);
472 if (previous->delay_usecs)
473 udelay(previous->delay_usecs);
474 }
475
476 dws->n_bytes = chip->n_bytes;
477 dws->dma_width = chip->dma_width;
478 dws->cs_control = chip->cs_control;
479
480 dws->rx_dma = transfer->rx_dma;
481 dws->tx_dma = transfer->tx_dma;
482 dws->tx = (void *)transfer->tx_buf;
483 dws->tx_end = dws->tx + transfer->len;
484 dws->rx = transfer->rx_buf;
485 dws->rx_end = dws->rx + transfer->len;
486 dws->write = dws->tx ? chip->write : null_writer;
487 dws->read = dws->rx ? chip->read : null_reader;
488 dws->cs_change = transfer->cs_change;
489 dws->len = dws->cur_transfer->len;
490 if (chip != dws->prev_chip)
491 cs_change = 1;
492
493 cr0 = chip->cr0;
494
495 /* Handle per transfer options for bpw and speed */
496 if (transfer->speed_hz) {
497 speed = chip->speed_hz;
498
499 if (transfer->speed_hz != speed) {
500 speed = transfer->speed_hz;
501 if (speed > dws->max_freq) {
502 printk(KERN_ERR "MRST SPI0: unsupported"
503 "freq: %dHz\n", speed);
504 message->status = -EIO;
505 goto early_exit;
506 }
507
508 /* clk_div doesn't support odd number */
509 clk_div = dws->max_freq / speed;
510 clk_div = (clk_div + 1) & 0xfffe;
511
512 chip->speed_hz = speed;
513 chip->clk_div = clk_div;
514 }
515 }
516 if (transfer->bits_per_word) {
517 bits = transfer->bits_per_word;
518
519 switch (bits) {
520 case 8:
521 dws->n_bytes = 1;
522 dws->dma_width = 1;
523 dws->read = (dws->read != null_reader) ?
524 u8_reader : null_reader;
525 dws->write = (dws->write != null_writer) ?
526 u8_writer : null_writer;
527 break;
528 case 16:
529 dws->n_bytes = 2;
530 dws->dma_width = 2;
531 dws->read = (dws->read != null_reader) ?
532 u16_reader : null_reader;
533 dws->write = (dws->write != null_writer) ?
534 u16_writer : null_writer;
535 break;
536 default:
537 printk(KERN_ERR "MRST SPI0: unsupported bits:"
538 "%db\n", bits);
539 message->status = -EIO;
540 goto early_exit;
541 }
542
543 cr0 = (bits - 1)
544 | (chip->type << SPI_FRF_OFFSET)
545 | (spi->mode << SPI_MODE_OFFSET)
546 | (chip->tmode << SPI_TMOD_OFFSET);
547 }
548 message->state = RUNNING_STATE;
549
550 /*
551 * Adjust transfer mode if necessary. Requires platform dependent
552 * chipselect mechanism.
553 */
554 if (dws->cs_control) {
555 if (dws->rx && dws->tx)
556 chip->tmode = SPI_TMOD_TR;
557 else if (dws->rx)
558 chip->tmode = SPI_TMOD_RO;
559 else
560 chip->tmode = SPI_TMOD_TO;
561
562 cr0 &= ~SPI_TMOD_MASK;
563 cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
564 }
565
566 /* Check if current transfer is a DMA transaction */
567 dws->dma_mapped = map_dma_buffers(dws);
568
569 /*
570 * Interrupt mode
571 * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
572 */
573 if (!dws->dma_mapped && !chip->poll_mode) {
574 int templen = dws->len / dws->n_bytes;
575 txint_level = dws->fifo_len / 2;
576 txint_level = (templen > txint_level) ? txint_level : templen;
577
578 imask |= SPI_INT_TXEI;
579 dws->transfer_handler = interrupt_transfer;
580 }
581
582 /*
583 * Reprogram registers only if
584 * 1. chip select changes
585 * 2. clk_div is changed
586 * 3. control value changes
587 */
588 if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) {
589 spi_enable_chip(dws, 0);
590
591 if (dw_readw(dws, ctrl0) != cr0)
592 dw_writew(dws, ctrl0, cr0);
593
594 spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
595 spi_chip_sel(dws, spi->chip_select);
596
597 /* Set the interrupt mask, for poll mode just disable all int */
598 spi_mask_intr(dws, 0xff);
599 if (imask)
600 spi_umask_intr(dws, imask);
601 if (txint_level)
602 dw_writew(dws, txfltr, txint_level);
603
604 spi_enable_chip(dws, 1);
605 if (cs_change)
606 dws->prev_chip = chip;
607 }
608
609 if (dws->dma_mapped)
610 dws->dma_ops->dma_transfer(dws, cs_change);
611
612 if (chip->poll_mode)
613 poll_transfer(dws);
614
615 return;
616
617 early_exit:
618 giveback(dws);
619 return;
620 }
621
622 static void pump_messages(struct work_struct *work)
623 {
624 struct dw_spi *dws =
625 container_of(work, struct dw_spi, pump_messages);
626 unsigned long flags;
627
628 /* Lock queue and check for queue work */
629 spin_lock_irqsave(&dws->lock, flags);
630 if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
631 dws->busy = 0;
632 spin_unlock_irqrestore(&dws->lock, flags);
633 return;
634 }
635
636 /* Make sure we are not already running a message */
637 if (dws->cur_msg) {
638 spin_unlock_irqrestore(&dws->lock, flags);
639 return;
640 }
641
642 /* Extract head of queue */
643 dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
644 list_del_init(&dws->cur_msg->queue);
645
646 /* Initial message state*/
647 dws->cur_msg->state = START_STATE;
648 dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
649 struct spi_transfer,
650 transfer_list);
651 dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
652
653 /* Mark as busy and launch transfers */
654 tasklet_schedule(&dws->pump_transfers);
655
656 dws->busy = 1;
657 spin_unlock_irqrestore(&dws->lock, flags);
658 }
659
660 /* spi_device use this to queue in their spi_msg */
661 static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
662 {
663 struct dw_spi *dws = spi_master_get_devdata(spi->master);
664 unsigned long flags;
665
666 spin_lock_irqsave(&dws->lock, flags);
667
668 if (dws->run == QUEUE_STOPPED) {
669 spin_unlock_irqrestore(&dws->lock, flags);
670 return -ESHUTDOWN;
671 }
672
673 msg->actual_length = 0;
674 msg->status = -EINPROGRESS;
675 msg->state = START_STATE;
676
677 list_add_tail(&msg->queue, &dws->queue);
678
679 if (dws->run == QUEUE_RUNNING && !dws->busy) {
680
681 if (dws->cur_transfer || dws->cur_msg)
682 queue_work(dws->workqueue,
683 &dws->pump_messages);
684 else {
685 /* If no other data transaction in air, just go */
686 spin_unlock_irqrestore(&dws->lock, flags);
687 pump_messages(&dws->pump_messages);
688 return 0;
689 }
690 }
691
692 spin_unlock_irqrestore(&dws->lock, flags);
693 return 0;
694 }
695
696 /* This may be called twice for each spi dev */
697 static int dw_spi_setup(struct spi_device *spi)
698 {
699 struct dw_spi_chip *chip_info = NULL;
700 struct chip_data *chip;
701
702 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
703 return -EINVAL;
704
705 /* Only alloc on first setup */
706 chip = spi_get_ctldata(spi);
707 if (!chip) {
708 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
709 if (!chip)
710 return -ENOMEM;
711 }
712
713 /*
714 * Protocol drivers may change the chip settings, so...
715 * if chip_info exists, use it
716 */
717 chip_info = spi->controller_data;
718
719 /* chip_info doesn't always exist */
720 if (chip_info) {
721 if (chip_info->cs_control)
722 chip->cs_control = chip_info->cs_control;
723
724 chip->poll_mode = chip_info->poll_mode;
725 chip->type = chip_info->type;
726
727 chip->rx_threshold = 0;
728 chip->tx_threshold = 0;
729
730 chip->enable_dma = chip_info->enable_dma;
731 }
732
733 if (spi->bits_per_word <= 8) {
734 chip->n_bytes = 1;
735 chip->dma_width = 1;
736 chip->read = u8_reader;
737 chip->write = u8_writer;
738 } else if (spi->bits_per_word <= 16) {
739 chip->n_bytes = 2;
740 chip->dma_width = 2;
741 chip->read = u16_reader;
742 chip->write = u16_writer;
743 } else {
744 /* Never take >16b case for MRST SPIC */
745 dev_err(&spi->dev, "invalid wordsize\n");
746 return -EINVAL;
747 }
748 chip->bits_per_word = spi->bits_per_word;
749
750 if (!spi->max_speed_hz) {
751 dev_err(&spi->dev, "No max speed HZ parameter\n");
752 return -EINVAL;
753 }
754 chip->speed_hz = spi->max_speed_hz;
755
756 chip->tmode = 0; /* Tx & Rx */
757 /* Default SPI mode is SCPOL = 0, SCPH = 0 */
758 chip->cr0 = (chip->bits_per_word - 1)
759 | (chip->type << SPI_FRF_OFFSET)
760 | (spi->mode << SPI_MODE_OFFSET)
761 | (chip->tmode << SPI_TMOD_OFFSET);
762
763 spi_set_ctldata(spi, chip);
764 return 0;
765 }
766
767 static void dw_spi_cleanup(struct spi_device *spi)
768 {
769 struct chip_data *chip = spi_get_ctldata(spi);
770 kfree(chip);
771 }
772
773 static int __devinit init_queue(struct dw_spi *dws)
774 {
775 INIT_LIST_HEAD(&dws->queue);
776 spin_lock_init(&dws->lock);
777
778 dws->run = QUEUE_STOPPED;
779 dws->busy = 0;
780
781 tasklet_init(&dws->pump_transfers,
782 pump_transfers, (unsigned long)dws);
783
784 INIT_WORK(&dws->pump_messages, pump_messages);
785 dws->workqueue = create_singlethread_workqueue(
786 dev_name(dws->master->dev.parent));
787 if (dws->workqueue == NULL)
788 return -EBUSY;
789
790 return 0;
791 }
792
793 static int start_queue(struct dw_spi *dws)
794 {
795 unsigned long flags;
796
797 spin_lock_irqsave(&dws->lock, flags);
798
799 if (dws->run == QUEUE_RUNNING || dws->busy) {
800 spin_unlock_irqrestore(&dws->lock, flags);
801 return -EBUSY;
802 }
803
804 dws->run = QUEUE_RUNNING;
805 dws->cur_msg = NULL;
806 dws->cur_transfer = NULL;
807 dws->cur_chip = NULL;
808 dws->prev_chip = NULL;
809 spin_unlock_irqrestore(&dws->lock, flags);
810
811 queue_work(dws->workqueue, &dws->pump_messages);
812
813 return 0;
814 }
815
816 static int stop_queue(struct dw_spi *dws)
817 {
818 unsigned long flags;
819 unsigned limit = 50;
820 int status = 0;
821
822 spin_lock_irqsave(&dws->lock, flags);
823 dws->run = QUEUE_STOPPED;
824 while ((!list_empty(&dws->queue) || dws->busy) && limit--) {
825 spin_unlock_irqrestore(&dws->lock, flags);
826 msleep(10);
827 spin_lock_irqsave(&dws->lock, flags);
828 }
829
830 if (!list_empty(&dws->queue) || dws->busy)
831 status = -EBUSY;
832 spin_unlock_irqrestore(&dws->lock, flags);
833
834 return status;
835 }
836
837 static int destroy_queue(struct dw_spi *dws)
838 {
839 int status;
840
841 status = stop_queue(dws);
842 if (status != 0)
843 return status;
844 destroy_workqueue(dws->workqueue);
845 return 0;
846 }
847
848 /* Restart the controller, disable all interrupts, clean rx fifo */
849 static void spi_hw_init(struct dw_spi *dws)
850 {
851 spi_enable_chip(dws, 0);
852 spi_mask_intr(dws, 0xff);
853 spi_enable_chip(dws, 1);
854 flush(dws);
855
856 /*
857 * Try to detect the FIFO depth if not set by interface driver,
858 * the depth could be from 2 to 256 from HW spec
859 */
860 if (!dws->fifo_len) {
861 u32 fifo;
862 for (fifo = 2; fifo <= 257; fifo++) {
863 dw_writew(dws, txfltr, fifo);
864 if (fifo != dw_readw(dws, txfltr))
865 break;
866 }
867
868 dws->fifo_len = (fifo == 257) ? 0 : fifo;
869 dw_writew(dws, txfltr, 0);
870 }
871 }
872
873 int __devinit dw_spi_add_host(struct dw_spi *dws)
874 {
875 struct spi_master *master;
876 int ret;
877
878 BUG_ON(dws == NULL);
879
880 master = spi_alloc_master(dws->parent_dev, 0);
881 if (!master) {
882 ret = -ENOMEM;
883 goto exit;
884 }
885
886 dws->master = master;
887 dws->type = SSI_MOTO_SPI;
888 dws->prev_chip = NULL;
889 dws->dma_inited = 0;
890 dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
891
892 ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED,
893 "dw_spi", dws);
894 if (ret < 0) {
895 dev_err(&master->dev, "can not get IRQ\n");
896 goto err_free_master;
897 }
898
899 master->mode_bits = SPI_CPOL | SPI_CPHA;
900 master->bus_num = dws->bus_num;
901 master->num_chipselect = dws->num_cs;
902 master->cleanup = dw_spi_cleanup;
903 master->setup = dw_spi_setup;
904 master->transfer = dw_spi_transfer;
905
906 /* Basic HW init */
907 spi_hw_init(dws);
908
909 if (dws->dma_ops && dws->dma_ops->dma_init) {
910 ret = dws->dma_ops->dma_init(dws);
911 if (ret) {
912 dev_warn(&master->dev, "DMA init failed\n");
913 dws->dma_inited = 0;
914 }
915 }
916
917 /* Initial and start queue */
918 ret = init_queue(dws);
919 if (ret) {
920 dev_err(&master->dev, "problem initializing queue\n");
921 goto err_diable_hw;
922 }
923 ret = start_queue(dws);
924 if (ret) {
925 dev_err(&master->dev, "problem starting queue\n");
926 goto err_diable_hw;
927 }
928
929 spi_master_set_devdata(master, dws);
930 ret = spi_register_master(master);
931 if (ret) {
932 dev_err(&master->dev, "problem registering spi master\n");
933 goto err_queue_alloc;
934 }
935
936 mrst_spi_debugfs_init(dws);
937 return 0;
938
939 err_queue_alloc:
940 destroy_queue(dws);
941 if (dws->dma_ops && dws->dma_ops->dma_exit)
942 dws->dma_ops->dma_exit(dws);
943 err_diable_hw:
944 spi_enable_chip(dws, 0);
945 free_irq(dws->irq, dws);
946 err_free_master:
947 spi_master_put(master);
948 exit:
949 return ret;
950 }
951 EXPORT_SYMBOL_GPL(dw_spi_add_host);
952
953 void __devexit dw_spi_remove_host(struct dw_spi *dws)
954 {
955 int status = 0;
956
957 if (!dws)
958 return;
959 mrst_spi_debugfs_remove(dws);
960
961 /* Remove the queue */
962 status = destroy_queue(dws);
963 if (status != 0)
964 dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
965 "complete, message memory not freed\n");
966
967 if (dws->dma_ops && dws->dma_ops->dma_exit)
968 dws->dma_ops->dma_exit(dws);
969 spi_enable_chip(dws, 0);
970 /* Disable clk */
971 spi_set_clk(dws, 0);
972 free_irq(dws->irq, dws);
973
974 /* Disconnect from the SPI framework */
975 spi_unregister_master(dws->master);
976 }
977 EXPORT_SYMBOL_GPL(dw_spi_remove_host);
978
979 int dw_spi_suspend_host(struct dw_spi *dws)
980 {
981 int ret = 0;
982
983 ret = stop_queue(dws);
984 if (ret)
985 return ret;
986 spi_enable_chip(dws, 0);
987 spi_set_clk(dws, 0);
988 return ret;
989 }
990 EXPORT_SYMBOL_GPL(dw_spi_suspend_host);
991
992 int dw_spi_resume_host(struct dw_spi *dws)
993 {
994 int ret;
995
996 spi_hw_init(dws);
997 ret = start_queue(dws);
998 if (ret)
999 dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
1000 return ret;
1001 }
1002 EXPORT_SYMBOL_GPL(dw_spi_resume_host);
1003
1004 MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
1005 MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
1006 MODULE_LICENSE("GPL v2");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree