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mpt2sas: Fix for system hang when discovery in progress
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / spi / dw_spi.c
blob919fa9d9e16bab34fef8af03a5a6286ac9fad394
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 void (*cs_control)(u32 command);
62 };
63
64 #ifdef CONFIG_DEBUG_FS
65 static int spi_show_regs_open(struct inode *inode, struct file *file)
66 {
67 file->private_data = inode->i_private;
68 return 0;
69 }
70
71 #define SPI_REGS_BUFSIZE 1024
72 static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
73 size_t count, loff_t *ppos)
74 {
75 struct dw_spi *dws;
76 char *buf;
77 u32 len = 0;
78 ssize_t ret;
79
80 dws = file->private_data;
81
82 buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
83 if (!buf)
84 return 0;
85
86 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
87 "MRST SPI0 registers:\n");
88 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
89 "=================================\n");
90 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
91 "CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
92 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
93 "CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
94 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
95 "SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
96 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
97 "SER: \t\t0x%08x\n", dw_readl(dws, ser));
98 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
99 "BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
100 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
101 "TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
102 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
103 "RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
104 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
105 "TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
106 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
107 "RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
108 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
109 "SR: \t\t0x%08x\n", dw_readl(dws, sr));
110 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
111 "IMR: \t\t0x%08x\n", dw_readl(dws, imr));
112 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
113 "ISR: \t\t0x%08x\n", dw_readl(dws, isr));
114 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
115 "DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
116 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
117 "DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
118 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
119 "DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
120 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
121 "=================================\n");
122
123 ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
124 kfree(buf);
125 return ret;
126 }
127
128 static const struct file_operations mrst_spi_regs_ops = {
129 .owner = THIS_MODULE,
130 .open = spi_show_regs_open,
131 .read = spi_show_regs,
132 .llseek = default_llseek,
133 };
134
135 static int mrst_spi_debugfs_init(struct dw_spi *dws)
136 {
137 dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
138 if (!dws->debugfs)
139 return -ENOMEM;
140
141 debugfs_create_file("registers", S_IFREG | S_IRUGO,
142 dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
143 return 0;
144 }
145
146 static void mrst_spi_debugfs_remove(struct dw_spi *dws)
147 {
148 if (dws->debugfs)
149 debugfs_remove_recursive(dws->debugfs);
150 }
151
152 #else
153 static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
154 {
155 return 0;
156 }
157
158 static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
159 {
160 }
161 #endif /* CONFIG_DEBUG_FS */
162
163 /* Return the max entries we can fill into tx fifo */
164 static inline u32 tx_max(struct dw_spi *dws)
165 {
166 u32 tx_left, tx_room, rxtx_gap;
167
168 tx_left = (dws->tx_end - dws->tx) / dws->n_bytes;
169 tx_room = dws->fifo_len - dw_readw(dws, txflr);
170
171 /*
172 * Another concern is about the tx/rx mismatch, we
173 * though to use (dws->fifo_len - rxflr - txflr) as
174 * one maximum value for tx, but it doesn't cover the
175 * data which is out of tx/rx fifo and inside the
176 * shift registers. So a control from sw point of
177 * view is taken.
178 */
179 rxtx_gap = ((dws->rx_end - dws->rx) - (dws->tx_end - dws->tx))
180 / dws->n_bytes;
181
182 return min3(tx_left, tx_room, (u32) (dws->fifo_len - rxtx_gap));
183 }
184
185 /* Return the max entries we should read out of rx fifo */
186 static inline u32 rx_max(struct dw_spi *dws)
187 {
188 u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes;
189
190 return min(rx_left, (u32)dw_readw(dws, rxflr));
191 }
192
193 static void dw_writer(struct dw_spi *dws)
194 {
195 u32 max = tx_max(dws);
196 u16 txw = 0;
197
198 while (max--) {
199 /* Set the tx word if the transfer's original "tx" is not null */
200 if (dws->tx_end - dws->len) {
201 if (dws->n_bytes == 1)
202 txw = *(u8 *)(dws->tx);
203 else
204 txw = *(u16 *)(dws->tx);
205 }
206 dw_writew(dws, dr, txw);
207 dws->tx += dws->n_bytes;
208 }
209 }
210
211 static void dw_reader(struct dw_spi *dws)
212 {
213 u32 max = rx_max(dws);
214 u16 rxw;
215
216 while (max--) {
217 rxw = dw_readw(dws, dr);
218 /* Care rx only if the transfer's original "rx" is not null */
219 if (dws->rx_end - dws->len) {
220 if (dws->n_bytes == 1)
221 *(u8 *)(dws->rx) = rxw;
222 else
223 *(u16 *)(dws->rx) = rxw;
224 }
225 dws->rx += dws->n_bytes;
226 }
227 }
228
229 static void *next_transfer(struct dw_spi *dws)
230 {
231 struct spi_message *msg = dws->cur_msg;
232 struct spi_transfer *trans = dws->cur_transfer;
233
234 /* Move to next transfer */
235 if (trans->transfer_list.next != &msg->transfers) {
236 dws->cur_transfer =
237 list_entry(trans->transfer_list.next,
238 struct spi_transfer,
239 transfer_list);
240 return RUNNING_STATE;
241 } else
242 return DONE_STATE;
243 }
244
245 /*
246 * Note: first step is the protocol driver prepares
247 * a dma-capable memory, and this func just need translate
248 * the virt addr to physical
249 */
250 static int map_dma_buffers(struct dw_spi *dws)
251 {
252 if (!dws->cur_msg->is_dma_mapped
253 || !dws->dma_inited
254 || !dws->cur_chip->enable_dma
255 || !dws->dma_ops)
256 return 0;
257
258 if (dws->cur_transfer->tx_dma)
259 dws->tx_dma = dws->cur_transfer->tx_dma;
260
261 if (dws->cur_transfer->rx_dma)
262 dws->rx_dma = dws->cur_transfer->rx_dma;
263
264 return 1;
265 }
266
267 /* Caller already set message->status; dma and pio irqs are blocked */
268 static void giveback(struct dw_spi *dws)
269 {
270 struct spi_transfer *last_transfer;
271 unsigned long flags;
272 struct spi_message *msg;
273
274 spin_lock_irqsave(&dws->lock, flags);
275 msg = dws->cur_msg;
276 dws->cur_msg = NULL;
277 dws->cur_transfer = NULL;
278 dws->prev_chip = dws->cur_chip;
279 dws->cur_chip = NULL;
280 dws->dma_mapped = 0;
281 queue_work(dws->workqueue, &dws->pump_messages);
282 spin_unlock_irqrestore(&dws->lock, flags);
283
284 last_transfer = list_entry(msg->transfers.prev,
285 struct spi_transfer,
286 transfer_list);
287
288 if (!last_transfer->cs_change && dws->cs_control)
289 dws->cs_control(MRST_SPI_DEASSERT);
290
291 msg->state = NULL;
292 if (msg->complete)
293 msg->complete(msg->context);
294 }
295
296 static void int_error_stop(struct dw_spi *dws, const char *msg)
297 {
298 /* Stop the hw */
299 spi_enable_chip(dws, 0);
300
301 dev_err(&dws->master->dev, "%s\n", msg);
302 dws->cur_msg->state = ERROR_STATE;
303 tasklet_schedule(&dws->pump_transfers);
304 }
305
306 void dw_spi_xfer_done(struct dw_spi *dws)
307 {
308 /* Update total byte transferred return count actual bytes read */
309 dws->cur_msg->actual_length += dws->len;
310
311 /* Move to next transfer */
312 dws->cur_msg->state = next_transfer(dws);
313
314 /* Handle end of message */
315 if (dws->cur_msg->state == DONE_STATE) {
316 dws->cur_msg->status = 0;
317 giveback(dws);
318 } else
319 tasklet_schedule(&dws->pump_transfers);
320 }
321 EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
322
323 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
324 {
325 u16 irq_status = dw_readw(dws, isr);
326
327 /* Error handling */
328 if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
329 dw_readw(dws, txoicr);
330 dw_readw(dws, rxoicr);
331 dw_readw(dws, rxuicr);
332 int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun");
333 return IRQ_HANDLED;
334 }
335
336 dw_reader(dws);
337 if (dws->rx_end == dws->rx) {
338 spi_mask_intr(dws, SPI_INT_TXEI);
339 dw_spi_xfer_done(dws);
340 return IRQ_HANDLED;
341 }
342 if (irq_status & SPI_INT_TXEI) {
343 spi_mask_intr(dws, SPI_INT_TXEI);
344 dw_writer(dws);
345 /* Enable TX irq always, it will be disabled when RX finished */
346 spi_umask_intr(dws, SPI_INT_TXEI);
347 }
348
349 return IRQ_HANDLED;
350 }
351
352 static irqreturn_t dw_spi_irq(int irq, void *dev_id)
353 {
354 struct dw_spi *dws = dev_id;
355 u16 irq_status = dw_readw(dws, isr) & 0x3f;
356
357 if (!irq_status)
358 return IRQ_NONE;
359
360 if (!dws->cur_msg) {
361 spi_mask_intr(dws, SPI_INT_TXEI);
362 return IRQ_HANDLED;
363 }
364
365 return dws->transfer_handler(dws);
366 }
367
368 /* Must be called inside pump_transfers() */
369 static void poll_transfer(struct dw_spi *dws)
370 {
371 do {
372 dw_writer(dws);
373 dw_reader(dws);
374 cpu_relax();
375 } while (dws->rx_end > dws->rx);
376
377 dw_spi_xfer_done(dws);
378 }
379
380 static void pump_transfers(unsigned long data)
381 {
382 struct dw_spi *dws = (struct dw_spi *)data;
383 struct spi_message *message = NULL;
384 struct spi_transfer *transfer = NULL;
385 struct spi_transfer *previous = NULL;
386 struct spi_device *spi = NULL;
387 struct chip_data *chip = NULL;
388 u8 bits = 0;
389 u8 imask = 0;
390 u8 cs_change = 0;
391 u16 txint_level = 0;
392 u16 clk_div = 0;
393 u32 speed = 0;
394 u32 cr0 = 0;
395
396 /* Get current state information */
397 message = dws->cur_msg;
398 transfer = dws->cur_transfer;
399 chip = dws->cur_chip;
400 spi = message->spi;
401
402 if (unlikely(!chip->clk_div))
403 chip->clk_div = dws->max_freq / chip->speed_hz;
404
405 if (message->state == ERROR_STATE) {
406 message->status = -EIO;
407 goto early_exit;
408 }
409
410 /* Handle end of message */
411 if (message->state == DONE_STATE) {
412 message->status = 0;
413 goto early_exit;
414 }
415
416 /* Delay if requested at end of transfer*/
417 if (message->state == RUNNING_STATE) {
418 previous = list_entry(transfer->transfer_list.prev,
419 struct spi_transfer,
420 transfer_list);
421 if (previous->delay_usecs)
422 udelay(previous->delay_usecs);
423 }
424
425 dws->n_bytes = chip->n_bytes;
426 dws->dma_width = chip->dma_width;
427 dws->cs_control = chip->cs_control;
428
429 dws->rx_dma = transfer->rx_dma;
430 dws->tx_dma = transfer->tx_dma;
431 dws->tx = (void *)transfer->tx_buf;
432 dws->tx_end = dws->tx + transfer->len;
433 dws->rx = transfer->rx_buf;
434 dws->rx_end = dws->rx + transfer->len;
435 dws->cs_change = transfer->cs_change;
436 dws->len = dws->cur_transfer->len;
437 if (chip != dws->prev_chip)
438 cs_change = 1;
439
440 cr0 = chip->cr0;
441
442 /* Handle per transfer options for bpw and speed */
443 if (transfer->speed_hz) {
444 speed = chip->speed_hz;
445
446 if (transfer->speed_hz != speed) {
447 speed = transfer->speed_hz;
448 if (speed > dws->max_freq) {
449 printk(KERN_ERR "MRST SPI0: unsupported"
450 "freq: %dHz\n", speed);
451 message->status = -EIO;
452 goto early_exit;
453 }
454
455 /* clk_div doesn't support odd number */
456 clk_div = dws->max_freq / speed;
457 clk_div = (clk_div + 1) & 0xfffe;
458
459 chip->speed_hz = speed;
460 chip->clk_div = clk_div;
461 }
462 }
463 if (transfer->bits_per_word) {
464 bits = transfer->bits_per_word;
465
466 switch (bits) {
467 case 8:
468 case 16:
469 dws->n_bytes = dws->dma_width = bits >> 3;
470 break;
471 default:
472 printk(KERN_ERR "MRST SPI0: unsupported bits:"
473 "%db\n", bits);
474 message->status = -EIO;
475 goto early_exit;
476 }
477
478 cr0 = (bits - 1)
479 | (chip->type << SPI_FRF_OFFSET)
480 | (spi->mode << SPI_MODE_OFFSET)
481 | (chip->tmode << SPI_TMOD_OFFSET);
482 }
483 message->state = RUNNING_STATE;
484
485 /*
486 * Adjust transfer mode if necessary. Requires platform dependent
487 * chipselect mechanism.
488 */
489 if (dws->cs_control) {
490 if (dws->rx && dws->tx)
491 chip->tmode = SPI_TMOD_TR;
492 else if (dws->rx)
493 chip->tmode = SPI_TMOD_RO;
494 else
495 chip->tmode = SPI_TMOD_TO;
496
497 cr0 &= ~SPI_TMOD_MASK;
498 cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
499 }
500
501 /* Check if current transfer is a DMA transaction */
502 dws->dma_mapped = map_dma_buffers(dws);
503
504 /*
505 * Interrupt mode
506 * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
507 */
508 if (!dws->dma_mapped && !chip->poll_mode) {
509 int templen = dws->len / dws->n_bytes;
510 txint_level = dws->fifo_len / 2;
511 txint_level = (templen > txint_level) ? txint_level : templen;
512
513 imask |= SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI;
514 dws->transfer_handler = interrupt_transfer;
515 }
516
517 /*
518 * Reprogram registers only if
519 * 1. chip select changes
520 * 2. clk_div is changed
521 * 3. control value changes
522 */
523 if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) {
524 spi_enable_chip(dws, 0);
525
526 if (dw_readw(dws, ctrl0) != cr0)
527 dw_writew(dws, ctrl0, cr0);
528
529 spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
530 spi_chip_sel(dws, spi->chip_select);
531
532 /* Set the interrupt mask, for poll mode just disable all int */
533 spi_mask_intr(dws, 0xff);
534 if (imask)
535 spi_umask_intr(dws, imask);
536 if (txint_level)
537 dw_writew(dws, txfltr, txint_level);
538
539 spi_enable_chip(dws, 1);
540 if (cs_change)
541 dws->prev_chip = chip;
542 }
543
544 if (dws->dma_mapped)
545 dws->dma_ops->dma_transfer(dws, cs_change);
546
547 if (chip->poll_mode)
548 poll_transfer(dws);
549
550 return;
551
552 early_exit:
553 giveback(dws);
554 return;
555 }
556
557 static void pump_messages(struct work_struct *work)
558 {
559 struct dw_spi *dws =
560 container_of(work, struct dw_spi, pump_messages);
561 unsigned long flags;
562
563 /* Lock queue and check for queue work */
564 spin_lock_irqsave(&dws->lock, flags);
565 if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
566 dws->busy = 0;
567 spin_unlock_irqrestore(&dws->lock, flags);
568 return;
569 }
570
571 /* Make sure we are not already running a message */
572 if (dws->cur_msg) {
573 spin_unlock_irqrestore(&dws->lock, flags);
574 return;
575 }
576
577 /* Extract head of queue */
578 dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
579 list_del_init(&dws->cur_msg->queue);
580
581 /* Initial message state*/
582 dws->cur_msg->state = START_STATE;
583 dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
584 struct spi_transfer,
585 transfer_list);
586 dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
587
588 /* Mark as busy and launch transfers */
589 tasklet_schedule(&dws->pump_transfers);
590
591 dws->busy = 1;
592 spin_unlock_irqrestore(&dws->lock, flags);
593 }
594
595 /* spi_device use this to queue in their spi_msg */
596 static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
597 {
598 struct dw_spi *dws = spi_master_get_devdata(spi->master);
599 unsigned long flags;
600
601 spin_lock_irqsave(&dws->lock, flags);
602
603 if (dws->run == QUEUE_STOPPED) {
604 spin_unlock_irqrestore(&dws->lock, flags);
605 return -ESHUTDOWN;
606 }
607
608 msg->actual_length = 0;
609 msg->status = -EINPROGRESS;
610 msg->state = START_STATE;
611
612 list_add_tail(&msg->queue, &dws->queue);
613
614 if (dws->run == QUEUE_RUNNING && !dws->busy) {
615
616 if (dws->cur_transfer || dws->cur_msg)
617 queue_work(dws->workqueue,
618 &dws->pump_messages);
619 else {
620 /* If no other data transaction in air, just go */
621 spin_unlock_irqrestore(&dws->lock, flags);
622 pump_messages(&dws->pump_messages);
623 return 0;
624 }
625 }
626
627 spin_unlock_irqrestore(&dws->lock, flags);
628 return 0;
629 }
630
631 /* This may be called twice for each spi dev */
632 static int dw_spi_setup(struct spi_device *spi)
633 {
634 struct dw_spi_chip *chip_info = NULL;
635 struct chip_data *chip;
636
637 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
638 return -EINVAL;
639
640 /* Only alloc on first setup */
641 chip = spi_get_ctldata(spi);
642 if (!chip) {
643 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
644 if (!chip)
645 return -ENOMEM;
646 }
647
648 /*
649 * Protocol drivers may change the chip settings, so...
650 * if chip_info exists, use it
651 */
652 chip_info = spi->controller_data;
653
654 /* chip_info doesn't always exist */
655 if (chip_info) {
656 if (chip_info->cs_control)
657 chip->cs_control = chip_info->cs_control;
658
659 chip->poll_mode = chip_info->poll_mode;
660 chip->type = chip_info->type;
661
662 chip->rx_threshold = 0;
663 chip->tx_threshold = 0;
664
665 chip->enable_dma = chip_info->enable_dma;
666 }
667
668 if (spi->bits_per_word <= 8) {
669 chip->n_bytes = 1;
670 chip->dma_width = 1;
671 } else if (spi->bits_per_word <= 16) {
672 chip->n_bytes = 2;
673 chip->dma_width = 2;
674 } else {
675 /* Never take >16b case for MRST SPIC */
676 dev_err(&spi->dev, "invalid wordsize\n");
677 return -EINVAL;
678 }
679 chip->bits_per_word = spi->bits_per_word;
680
681 if (!spi->max_speed_hz) {
682 dev_err(&spi->dev, "No max speed HZ parameter\n");
683 return -EINVAL;
684 }
685 chip->speed_hz = spi->max_speed_hz;
686
687 chip->tmode = 0; /* Tx & Rx */
688 /* Default SPI mode is SCPOL = 0, SCPH = 0 */
689 chip->cr0 = (chip->bits_per_word - 1)
690 | (chip->type << SPI_FRF_OFFSET)
691 | (spi->mode << SPI_MODE_OFFSET)
692 | (chip->tmode << SPI_TMOD_OFFSET);
693
694 spi_set_ctldata(spi, chip);
695 return 0;
696 }
697
698 static void dw_spi_cleanup(struct spi_device *spi)
699 {
700 struct chip_data *chip = spi_get_ctldata(spi);
701 kfree(chip);
702 }
703
704 static int __devinit init_queue(struct dw_spi *dws)
705 {
706 INIT_LIST_HEAD(&dws->queue);
707 spin_lock_init(&dws->lock);
708
709 dws->run = QUEUE_STOPPED;
710 dws->busy = 0;
711
712 tasklet_init(&dws->pump_transfers,
713 pump_transfers, (unsigned long)dws);
714
715 INIT_WORK(&dws->pump_messages, pump_messages);
716 dws->workqueue = create_singlethread_workqueue(
717 dev_name(dws->master->dev.parent));
718 if (dws->workqueue == NULL)
719 return -EBUSY;
720
721 return 0;
722 }
723
724 static int start_queue(struct dw_spi *dws)
725 {
726 unsigned long flags;
727
728 spin_lock_irqsave(&dws->lock, flags);
729
730 if (dws->run == QUEUE_RUNNING || dws->busy) {
731 spin_unlock_irqrestore(&dws->lock, flags);
732 return -EBUSY;
733 }
734
735 dws->run = QUEUE_RUNNING;
736 dws->cur_msg = NULL;
737 dws->cur_transfer = NULL;
738 dws->cur_chip = NULL;
739 dws->prev_chip = NULL;
740 spin_unlock_irqrestore(&dws->lock, flags);
741
742 queue_work(dws->workqueue, &dws->pump_messages);
743
744 return 0;
745 }
746
747 static int stop_queue(struct dw_spi *dws)
748 {
749 unsigned long flags;
750 unsigned limit = 50;
751 int status = 0;
752
753 spin_lock_irqsave(&dws->lock, flags);
754 dws->run = QUEUE_STOPPED;
755 while ((!list_empty(&dws->queue) || dws->busy) && limit--) {
756 spin_unlock_irqrestore(&dws->lock, flags);
757 msleep(10);
758 spin_lock_irqsave(&dws->lock, flags);
759 }
760
761 if (!list_empty(&dws->queue) || dws->busy)
762 status = -EBUSY;
763 spin_unlock_irqrestore(&dws->lock, flags);
764
765 return status;
766 }
767
768 static int destroy_queue(struct dw_spi *dws)
769 {
770 int status;
771
772 status = stop_queue(dws);
773 if (status != 0)
774 return status;
775 destroy_workqueue(dws->workqueue);
776 return 0;
777 }
778
779 /* Restart the controller, disable all interrupts, clean rx fifo */
780 static void spi_hw_init(struct dw_spi *dws)
781 {
782 spi_enable_chip(dws, 0);
783 spi_mask_intr(dws, 0xff);
784 spi_enable_chip(dws, 1);
785
786 /*
787 * Try to detect the FIFO depth if not set by interface driver,
788 * the depth could be from 2 to 256 from HW spec
789 */
790 if (!dws->fifo_len) {
791 u32 fifo;
792 for (fifo = 2; fifo <= 257; fifo++) {
793 dw_writew(dws, txfltr, fifo);
794 if (fifo != dw_readw(dws, txfltr))
795 break;
796 }
797
798 dws->fifo_len = (fifo == 257) ? 0 : fifo;
799 dw_writew(dws, txfltr, 0);
800 }
801 }
802
803 int __devinit dw_spi_add_host(struct dw_spi *dws)
804 {
805 struct spi_master *master;
806 int ret;
807
808 BUG_ON(dws == NULL);
809
810 master = spi_alloc_master(dws->parent_dev, 0);
811 if (!master) {
812 ret = -ENOMEM;
813 goto exit;
814 }
815
816 dws->master = master;
817 dws->type = SSI_MOTO_SPI;
818 dws->prev_chip = NULL;
819 dws->dma_inited = 0;
820 dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
821
822 ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED,
823 "dw_spi", dws);
824 if (ret < 0) {
825 dev_err(&master->dev, "can not get IRQ\n");
826 goto err_free_master;
827 }
828
829 master->mode_bits = SPI_CPOL | SPI_CPHA;
830 master->bus_num = dws->bus_num;
831 master->num_chipselect = dws->num_cs;
832 master->cleanup = dw_spi_cleanup;
833 master->setup = dw_spi_setup;
834 master->transfer = dw_spi_transfer;
835
836 /* Basic HW init */
837 spi_hw_init(dws);
838
839 if (dws->dma_ops && dws->dma_ops->dma_init) {
840 ret = dws->dma_ops->dma_init(dws);
841 if (ret) {
842 dev_warn(&master->dev, "DMA init failed\n");
843 dws->dma_inited = 0;
844 }
845 }
846
847 /* Initial and start queue */
848 ret = init_queue(dws);
849 if (ret) {
850 dev_err(&master->dev, "problem initializing queue\n");
851 goto err_diable_hw;
852 }
853 ret = start_queue(dws);
854 if (ret) {
855 dev_err(&master->dev, "problem starting queue\n");
856 goto err_diable_hw;
857 }
858
859 spi_master_set_devdata(master, dws);
860 ret = spi_register_master(master);
861 if (ret) {
862 dev_err(&master->dev, "problem registering spi master\n");
863 goto err_queue_alloc;
864 }
865
866 mrst_spi_debugfs_init(dws);
867 return 0;
868
869 err_queue_alloc:
870 destroy_queue(dws);
871 if (dws->dma_ops && dws->dma_ops->dma_exit)
872 dws->dma_ops->dma_exit(dws);
873 err_diable_hw:
874 spi_enable_chip(dws, 0);
875 free_irq(dws->irq, dws);
876 err_free_master:
877 spi_master_put(master);
878 exit:
879 return ret;
880 }
881 EXPORT_SYMBOL_GPL(dw_spi_add_host);
882
883 void __devexit dw_spi_remove_host(struct dw_spi *dws)
884 {
885 int status = 0;
886
887 if (!dws)
888 return;
889 mrst_spi_debugfs_remove(dws);
890
891 /* Remove the queue */
892 status = destroy_queue(dws);
893 if (status != 0)
894 dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
895 "complete, message memory not freed\n");
896
897 if (dws->dma_ops && dws->dma_ops->dma_exit)
898 dws->dma_ops->dma_exit(dws);
899 spi_enable_chip(dws, 0);
900 /* Disable clk */
901 spi_set_clk(dws, 0);
902 free_irq(dws->irq, dws);
903
904 /* Disconnect from the SPI framework */
905 spi_unregister_master(dws->master);
906 }
907 EXPORT_SYMBOL_GPL(dw_spi_remove_host);
908
909 int dw_spi_suspend_host(struct dw_spi *dws)
910 {
911 int ret = 0;
912
913 ret = stop_queue(dws);
914 if (ret)
915 return ret;
916 spi_enable_chip(dws, 0);
917 spi_set_clk(dws, 0);
918 return ret;
919 }
920 EXPORT_SYMBOL_GPL(dw_spi_suspend_host);
921
922 int dw_spi_resume_host(struct dw_spi *dws)
923 {
924 int ret;
925
926 spi_hw_init(dws);
927 ret = start_queue(dws);
928 if (ret)
929 dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
930 return ret;
931 }
932 EXPORT_SYMBOL_GPL(dw_spi_resume_host);
933
934 MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
935 MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
936 MODULE_LICENSE("GPL v2");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree