1 /*
2 * 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/module.h>
23 #include <linux/highmem.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/spi/spi.h>
27
28 #include "spi-dw.h"
29
30 #ifdef CONFIG_DEBUG_FS
31 #include <linux/debugfs.h>
32 #endif
33
34 #define START_STATE ((void *)0)
35 #define RUNNING_STATE ((void *)1)
36 #define DONE_STATE ((void *)2)
37 #define ERROR_STATE ((void *)-1)
38
39 #define QUEUE_RUNNING 0
40 #define QUEUE_STOPPED 1
41
42 #define MRST_SPI_DEASSERT 0
43 #define MRST_SPI_ASSERT 1
44
45 /* Slave spi_dev related */
46 struct chip_data {
47 u16 cr0;
48 u8 cs; /* chip select pin */
49 u8 n_bytes; /* current is a 1/2/4 byte op */
50 u8 tmode; /* TR/TO/RO/EEPROM */
51 u8 type; /* SPI/SSP/MicroWire */
52
53 u8 poll_mode; /* 1 means use poll mode */
54
55 u32 dma_width;
56 u32 rx_threshold;
57 u32 tx_threshold;
58 u8 enable_dma;
59 u8 bits_per_word;
60 u16 clk_div; /* baud rate divider */
61 u32 speed_hz; /* baud rate */
62 void (*cs_control)(u32 command);
63 };
64
65 #ifdef CONFIG_DEBUG_FS
spi_show_regs_open(struct inode * inode,struct file * file)66 static int spi_show_regs_open(struct inode *inode, struct file *file)
67 {
68 file->private_data = inode->i_private;
69 return 0;
70 }
71
72 #define SPI_REGS_BUFSIZE 1024
spi_show_regs(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)73 static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
74 size_t count, loff_t *ppos)
75 {
76 struct dw_spi *dws;
77 char *buf;
78 u32 len = 0;
79 ssize_t ret;
80
81 dws = file->private_data;
82
83 buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
84 if (!buf)
85 return 0;
86
87 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
88 "MRST SPI0 registers:\n");
89 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
90 "=================================\n");
91 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
92 "CTRL0: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL0));
93 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
94 "CTRL1: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL1));
95 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
96 "SSIENR: \t0x%08x\n", dw_readl(dws, DW_SPI_SSIENR));
97 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
98 "SER: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SER));
99 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
100 "BAUDR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_BAUDR));
101 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
102 "TXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_TXFLTR));
103 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
104 "RXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_RXFLTR));
105 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
106 "TXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_TXFLR));
107 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
108 "RXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_RXFLR));
109 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
110 "SR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SR));
111 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
112 "IMR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_IMR));
113 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
114 "ISR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_ISR));
115 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
116 "DMACR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_DMACR));
117 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
118 "DMATDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMATDLR));
119 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
120 "DMARDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMARDLR));
121 len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
122 "=================================\n");
123
124 ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
125 kfree(buf);
126 return ret;
127 }
128
129 static const struct file_operations mrst_spi_regs_ops = {
130 .owner = THIS_MODULE,
131 .open = spi_show_regs_open,
132 .read = spi_show_regs,
133 .llseek = default_llseek,
134 };
135
mrst_spi_debugfs_init(struct dw_spi * dws)136 static int mrst_spi_debugfs_init(struct dw_spi *dws)
137 {
138 dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
139 if (!dws->debugfs)
140 return -ENOMEM;
141
142 debugfs_create_file("registers", S_IFREG | S_IRUGO,
143 dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
144 return 0;
145 }
146
mrst_spi_debugfs_remove(struct dw_spi * dws)147 static void mrst_spi_debugfs_remove(struct dw_spi *dws)
148 {
149 if (dws->debugfs)
150 debugfs_remove_recursive(dws->debugfs);
151 }
152
153 #else
mrst_spi_debugfs_init(struct dw_spi * dws)154 static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
155 {
156 return 0;
157 }
158
mrst_spi_debugfs_remove(struct dw_spi * dws)159 static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
160 {
161 }
162 #endif /* CONFIG_DEBUG_FS */
163
164 /* Return the max entries we can fill into tx fifo */
tx_max(struct dw_spi * dws)165 static inline u32 tx_max(struct dw_spi *dws)
166 {
167 u32 tx_left, tx_room, rxtx_gap;
168
169 tx_left = (dws->tx_end - dws->tx) / dws->n_bytes;
170 tx_room = dws->fifo_len - dw_readw(dws, DW_SPI_TXFLR);
171
172 /*
173 * Another concern is about the tx/rx mismatch, we
174 * though to use (dws->fifo_len - rxflr - txflr) as
175 * one maximum value for tx, but it doesn't cover the
176 * data which is out of tx/rx fifo and inside the
177 * shift registers. So a control from sw point of
178 * view is taken.
179 */
180 rxtx_gap = ((dws->rx_end - dws->rx) - (dws->tx_end - dws->tx))
181 / dws->n_bytes;
182
183 return min3(tx_left, tx_room, (u32) (dws->fifo_len - rxtx_gap));
184 }
185
186 /* Return the max entries we should read out of rx fifo */
rx_max(struct dw_spi * dws)187 static inline u32 rx_max(struct dw_spi *dws)
188 {
189 u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes;
190
191 return min(rx_left, (u32)dw_readw(dws, DW_SPI_RXFLR));
192 }
193
dw_writer(struct dw_spi * dws)194 static void dw_writer(struct dw_spi *dws)
195 {
196 u32 max = tx_max(dws);
197 u16 txw = 0;
198
199 while (max--) {
200 /* Set the tx word if the transfer's original "tx" is not null */
201 if (dws->tx_end - dws->len) {
202 if (dws->n_bytes == 1)
203 txw = *(u8 *)(dws->tx);
204 else
205 txw = *(u16 *)(dws->tx);
206 }
207 dw_writew(dws, DW_SPI_DR, txw);
208 dws->tx += dws->n_bytes;
209 }
210 }
211
dw_reader(struct dw_spi * dws)212 static void dw_reader(struct dw_spi *dws)
213 {
214 u32 max = rx_max(dws);
215 u16 rxw;
216
217 while (max--) {
218 rxw = dw_readw(dws, DW_SPI_DR);
219 /* Care rx only if the transfer's original "rx" is not null */
220 if (dws->rx_end - dws->len) {
221 if (dws->n_bytes == 1)
222 *(u8 *)(dws->rx) = rxw;
223 else
224 *(u16 *)(dws->rx) = rxw;
225 }
226 dws->rx += dws->n_bytes;
227 }
228 }
229
next_transfer(struct dw_spi * dws)230 static void *next_transfer(struct dw_spi *dws)
231 {
232 struct spi_message *msg = dws->cur_msg;
233 struct spi_transfer *trans = dws->cur_transfer;
234
235 /* Move to next transfer */
236 if (trans->transfer_list.next != &msg->transfers) {
237 dws->cur_transfer =
238 list_entry(trans->transfer_list.next,
239 struct spi_transfer,
240 transfer_list);
241 return RUNNING_STATE;
242 } else
243 return DONE_STATE;
244 }
245
246 /*
247 * Note: first step is the protocol driver prepares
248 * a dma-capable memory, and this func just need translate
249 * the virt addr to physical
250 */
map_dma_buffers(struct dw_spi * dws)251 static int map_dma_buffers(struct dw_spi *dws)
252 {
253 if (!dws->cur_msg->is_dma_mapped
254 || !dws->dma_inited
255 || !dws->cur_chip->enable_dma
256 || !dws->dma_ops)
257 return 0;
258
259 if (dws->cur_transfer->tx_dma)
260 dws->tx_dma = dws->cur_transfer->tx_dma;
261
262 if (dws->cur_transfer->rx_dma)
263 dws->rx_dma = dws->cur_transfer->rx_dma;
264
265 return 1;
266 }
267
268 /* Caller already set message->status; dma and pio irqs are blocked */
giveback(struct dw_spi * dws)269 static void giveback(struct dw_spi *dws)
270 {
271 struct spi_transfer *last_transfer;
272 unsigned long flags;
273 struct spi_message *msg;
274
275 spin_lock_irqsave(&dws->lock, flags);
276 msg = dws->cur_msg;
277 dws->cur_msg = NULL;
278 dws->cur_transfer = NULL;
279 dws->prev_chip = dws->cur_chip;
280 dws->cur_chip = NULL;
281 dws->dma_mapped = 0;
282 queue_work(dws->workqueue, &dws->pump_messages);
283 spin_unlock_irqrestore(&dws->lock, flags);
284
285 last_transfer = list_entry(msg->transfers.prev,
286 struct spi_transfer,
287 transfer_list);
288
289 if (!last_transfer->cs_change && dws->cs_control)
290 dws->cs_control(MRST_SPI_DEASSERT);
291
292 msg->state = NULL;
293 if (msg->complete)
294 msg->complete(msg->context);
295 }
296
int_error_stop(struct dw_spi * dws,const char * msg)297 static void int_error_stop(struct dw_spi *dws, const char *msg)
298 {
299 /* Stop the hw */
300 spi_enable_chip(dws, 0);
301
302 dev_err(&dws->master->dev, "%s\n", msg);
303 dws->cur_msg->state = ERROR_STATE;
304 tasklet_schedule(&dws->pump_transfers);
305 }
306
dw_spi_xfer_done(struct dw_spi * dws)307 void dw_spi_xfer_done(struct dw_spi *dws)
308 {
309 /* Update total byte transferred return count actual bytes read */
310 dws->cur_msg->actual_length += dws->len;
311
312 /* Move to next transfer */
313 dws->cur_msg->state = next_transfer(dws);
314
315 /* Handle end of message */
316 if (dws->cur_msg->state == DONE_STATE) {
317 dws->cur_msg->status = 0;
318 giveback(dws);
319 } else
320 tasklet_schedule(&dws->pump_transfers);
321 }
322 EXPORT_SYMBOL_GPL(dw_spi_xfer_done);
323
interrupt_transfer(struct dw_spi * dws)324 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
325 {
326 u16 irq_status = dw_readw(dws, DW_SPI_ISR);
327
328 /* Error handling */
329 if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
330 dw_readw(dws, DW_SPI_TXOICR);
331 dw_readw(dws, DW_SPI_RXOICR);
332 dw_readw(dws, DW_SPI_RXUICR);
333 int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun");
334 return IRQ_HANDLED;
335 }
336
337 dw_reader(dws);
338 if (dws->rx_end == dws->rx) {
339 spi_mask_intr(dws, SPI_INT_TXEI);
340 dw_spi_xfer_done(dws);
341 return IRQ_HANDLED;
342 }
343 if (irq_status & SPI_INT_TXEI) {
344 spi_mask_intr(dws, SPI_INT_TXEI);
345 dw_writer(dws);
346 /* Enable TX irq always, it will be disabled when RX finished */
347 spi_umask_intr(dws, SPI_INT_TXEI);
348 }
349
350 return IRQ_HANDLED;
351 }
352
dw_spi_irq(int irq,void * dev_id)353 static irqreturn_t dw_spi_irq(int irq, void *dev_id)
354 {
355 struct dw_spi *dws = dev_id;
356 u16 irq_status = dw_readw(dws, DW_SPI_ISR) & 0x3f;
357
358 if (!irq_status)
359 return IRQ_NONE;
360
361 if (!dws->cur_msg) {
362 spi_mask_intr(dws, SPI_INT_TXEI);
363 return IRQ_HANDLED;
364 }
365
366 return dws->transfer_handler(dws);
367 }
368
369 /* Must be called inside pump_transfers() */
poll_transfer(struct dw_spi * dws)370 static void poll_transfer(struct dw_spi *dws)
371 {
372 do {
373 dw_writer(dws);
374 dw_reader(dws);
375 cpu_relax();
376 } while (dws->rx_end > dws->rx);
377
378 dw_spi_xfer_done(dws);
379 }
380
pump_transfers(unsigned long data)381 static void pump_transfers(unsigned long data)
382 {
383 struct dw_spi *dws = (struct dw_spi *)data;
384 struct spi_message *message = NULL;
385 struct spi_transfer *transfer = NULL;
386 struct spi_transfer *previous = NULL;
387 struct spi_device *spi = NULL;
388 struct chip_data *chip = NULL;
389 u8 bits = 0;
390 u8 imask = 0;
391 u8 cs_change = 0;
392 u16 txint_level = 0;
393 u16 clk_div = 0;
394 u32 speed = 0;
395 u32 cr0 = 0;
396
397 /* Get current state information */
398 message = dws->cur_msg;
399 transfer = dws->cur_transfer;
400 chip = dws->cur_chip;
401 spi = message->spi;
402
403 if (unlikely(!chip->clk_div))
404 chip->clk_div = dws->max_freq / chip->speed_hz;
405
406 if (message->state == ERROR_STATE) {
407 message->status = -EIO;
408 goto early_exit;
409 }
410
411 /* Handle end of message */
412 if (message->state == DONE_STATE) {
413 message->status = 0;
414 goto early_exit;
415 }
416
417 /* Delay if requested at end of transfer*/
418 if (message->state == RUNNING_STATE) {
419 previous = list_entry(transfer->transfer_list.prev,
420 struct spi_transfer,
421 transfer_list);
422 if (previous->delay_usecs)
423 udelay(previous->delay_usecs);
424 }
425
426 dws->n_bytes = chip->n_bytes;
427 dws->dma_width = chip->dma_width;
428 dws->cs_control = chip->cs_control;
429
430 dws->rx_dma = transfer->rx_dma;
431 dws->tx_dma = transfer->tx_dma;
432 dws->tx = (void *)transfer->tx_buf;
433 dws->tx_end = dws->tx + transfer->len;
434 dws->rx = transfer->rx_buf;
435 dws->rx_end = dws->rx + transfer->len;
436 dws->cs_change = transfer->cs_change;
437 dws->len = dws->cur_transfer->len;
438 if (chip != dws->prev_chip)
439 cs_change = 1;
440
441 cr0 = chip->cr0;
442
443 /* Handle per transfer options for bpw and speed */
444 if (transfer->speed_hz) {
445 speed = chip->speed_hz;
446
447 if (transfer->speed_hz != speed) {
448 speed = transfer->speed_hz;
449 if (speed > dws->max_freq) {
450 printk(KERN_ERR "MRST SPI0: unsupported"
451 "freq: %dHz\n", speed);
452 message->status = -EIO;
453 goto early_exit;
454 }
455
456 /* clk_div doesn't support odd number */
457 clk_div = dws->max_freq / speed;
458 clk_div = (clk_div + 1) & 0xfffe;
459
460 chip->speed_hz = speed;
461 chip->clk_div = clk_div;
462 }
463 }
464 if (transfer->bits_per_word) {
465 bits = transfer->bits_per_word;
466
467 switch (bits) {
468 case 8:
469 case 16:
470 dws->n_bytes = dws->dma_width = bits >> 3;
471 break;
472 default:
473 printk(KERN_ERR "MRST SPI0: unsupported bits:"
474 "%db\n", bits);
475 message->status = -EIO;
476 goto early_exit;
477 }
478
479 cr0 = (bits - 1)
480 | (chip->type << SPI_FRF_OFFSET)
481 | (spi->mode << SPI_MODE_OFFSET)
482 | (chip->tmode << SPI_TMOD_OFFSET);
483 }
484 message->state = RUNNING_STATE;
485
486 /*
487 * Adjust transfer mode if necessary. Requires platform dependent
488 * chipselect mechanism.
489 */
490 if (dws->cs_control) {
491 if (dws->rx && dws->tx)
492 chip->tmode = SPI_TMOD_TR;
493 else if (dws->rx)
494 chip->tmode = SPI_TMOD_RO;
495 else
496 chip->tmode = SPI_TMOD_TO;
497
498 cr0 &= ~SPI_TMOD_MASK;
499 cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
500 }
501
502 /* Check if current transfer is a DMA transaction */
503 dws->dma_mapped = map_dma_buffers(dws);
504
505 /*
506 * Interrupt mode
507 * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
508 */
509 if (!dws->dma_mapped && !chip->poll_mode) {
510 int templen = dws->len / dws->n_bytes;
511 txint_level = dws->fifo_len / 2;
512 txint_level = (templen > txint_level) ? txint_level : templen;
513
514 imask |= SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI;
515 dws->transfer_handler = interrupt_transfer;
516 }
517
518 /*
519 * Reprogram registers only if
520 * 1. chip select changes
521 * 2. clk_div is changed
522 * 3. control value changes
523 */
524 if (dw_readw(dws, DW_SPI_CTRL0) != cr0 || cs_change || clk_div || imask) {
525 spi_enable_chip(dws, 0);
526
527 if (dw_readw(dws, DW_SPI_CTRL0) != cr0)
528 dw_writew(dws, DW_SPI_CTRL0, cr0);
529
530 spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
531 spi_chip_sel(dws, spi->chip_select);
532
533 /* Set the interrupt mask, for poll mode just disable all int */
534 spi_mask_intr(dws, 0xff);
535 if (imask)
536 spi_umask_intr(dws, imask);
537 if (txint_level)
538 dw_writew(dws, DW_SPI_TXFLTR, txint_level);
539
540 spi_enable_chip(dws, 1);
541 if (cs_change)
542 dws->prev_chip = chip;
543 }
544
545 if (dws->dma_mapped)
546 dws->dma_ops->dma_transfer(dws, cs_change);
547
548 if (chip->poll_mode)
549 poll_transfer(dws);
550
551 return;
552
553 early_exit:
554 giveback(dws);
555 return;
556 }
557
pump_messages(struct work_struct * work)558 static void pump_messages(struct work_struct *work)
559 {
560 struct dw_spi *dws =
561 container_of(work, struct dw_spi, pump_messages);
562 unsigned long flags;
563
564 /* Lock queue and check for queue work */
565 spin_lock_irqsave(&dws->lock, flags);
566 if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
567 dws->busy = 0;
568 spin_unlock_irqrestore(&dws->lock, flags);
569 return;
570 }
571
572 /* Make sure we are not already running a message */
573 if (dws->cur_msg) {
574 spin_unlock_irqrestore(&dws->lock, flags);
575 return;
576 }
577
578 /* Extract head of queue */
579 dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
580 list_del_init(&dws->cur_msg->queue);
581
582 /* Initial message state*/
583 dws->cur_msg->state = START_STATE;
584 dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
585 struct spi_transfer,
586 transfer_list);
587 dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
588
589 /* Mark as busy and launch transfers */
590 tasklet_schedule(&dws->pump_transfers);
591
592 dws->busy = 1;
593 spin_unlock_irqrestore(&dws->lock, flags);
594 }
595
596 /* spi_device use this to queue in their spi_msg */
dw_spi_transfer(struct spi_device * spi,struct spi_message * msg)597 static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
598 {
599 struct dw_spi *dws = spi_master_get_devdata(spi->master);
600 unsigned long flags;
601
602 spin_lock_irqsave(&dws->lock, flags);
603
604 if (dws->run == QUEUE_STOPPED) {
605 spin_unlock_irqrestore(&dws->lock, flags);
606 return -ESHUTDOWN;
607 }
608
609 msg->actual_length = 0;
610 msg->status = -EINPROGRESS;
611 msg->state = START_STATE;
612
613 list_add_tail(&msg->queue, &dws->queue);
614
615 if (dws->run == QUEUE_RUNNING && !dws->busy) {
616
617 if (dws->cur_transfer || dws->cur_msg)
618 queue_work(dws->workqueue,
619 &dws->pump_messages);
620 else {
621 /* If no other data transaction in air, just go */
622 spin_unlock_irqrestore(&dws->lock, flags);
623 pump_messages(&dws->pump_messages);
624 return 0;
625 }
626 }
627
628 spin_unlock_irqrestore(&dws->lock, flags);
629 return 0;
630 }
631
632 /* This may be called twice for each spi dev */
dw_spi_setup(struct spi_device * spi)633 static int dw_spi_setup(struct spi_device *spi)
634 {
635 struct dw_spi_chip *chip_info = NULL;
636 struct chip_data *chip;
637
638 if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
639 return -EINVAL;
640
641 /* Only alloc on first setup */
642 chip = spi_get_ctldata(spi);
643 if (!chip) {
644 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
645 if (!chip)
646 return -ENOMEM;
647 }
648
649 /*
650 * Protocol drivers may change the chip settings, so...
651 * if chip_info exists, use it
652 */
653 chip_info = spi->controller_data;
654
655 /* chip_info doesn't always exist */
656 if (chip_info) {
657 if (chip_info->cs_control)
658 chip->cs_control = chip_info->cs_control;
659
660 chip->poll_mode = chip_info->poll_mode;
661 chip->type = chip_info->type;
662
663 chip->rx_threshold = 0;
664 chip->tx_threshold = 0;
665
666 chip->enable_dma = chip_info->enable_dma;
667 }
668
669 if (spi->bits_per_word <= 8) {
670 chip->n_bytes = 1;
671 chip->dma_width = 1;
672 } else if (spi->bits_per_word <= 16) {
673 chip->n_bytes = 2;
674 chip->dma_width = 2;
675 } else {
676 /* Never take >16b case for MRST SPIC */
677 dev_err(&spi->dev, "invalid wordsize\n");
678 return -EINVAL;
679 }
680 chip->bits_per_word = spi->bits_per_word;
681
682 if (!spi->max_speed_hz) {
683 dev_err(&spi->dev, "No max speed HZ parameter\n");
684 return -EINVAL;
685 }
686 chip->speed_hz = spi->max_speed_hz;
687
688 chip->tmode = 0; /* Tx & Rx */
689 /* Default SPI mode is SCPOL = 0, SCPH = 0 */
690 chip->cr0 = (chip->bits_per_word - 1)
691 | (chip->type << SPI_FRF_OFFSET)
692 | (spi->mode << SPI_MODE_OFFSET)
693 | (chip->tmode << SPI_TMOD_OFFSET);
694
695 spi_set_ctldata(spi, chip);
696 return 0;
697 }
698
dw_spi_cleanup(struct spi_device * spi)699 static void dw_spi_cleanup(struct spi_device *spi)
700 {
701 struct chip_data *chip = spi_get_ctldata(spi);
702 kfree(chip);
703 }
704
init_queue(struct dw_spi * dws)705 static int __devinit init_queue(struct dw_spi *dws)
706 {
707 INIT_LIST_HEAD(&dws->queue);
708 spin_lock_init(&dws->lock);
709
710 dws->run = QUEUE_STOPPED;
711 dws->busy = 0;
712
713 tasklet_init(&dws->pump_transfers,
714 pump_transfers, (unsigned long)dws);
715
716 INIT_WORK(&dws->pump_messages, pump_messages);
717 dws->workqueue = create_singlethread_workqueue(
718 dev_name(dws->master->dev.parent));
719 if (dws->workqueue == NULL)
720 return -EBUSY;
721
722 return 0;
723 }
724
start_queue(struct dw_spi * dws)725 static int start_queue(struct dw_spi *dws)
726 {
727 unsigned long flags;
728
729 spin_lock_irqsave(&dws->lock, flags);
730
731 if (dws->run == QUEUE_RUNNING || dws->busy) {
732 spin_unlock_irqrestore(&dws->lock, flags);
733 return -EBUSY;
734 }
735
736 dws->run = QUEUE_RUNNING;
737 dws->cur_msg = NULL;
738 dws->cur_transfer = NULL;
739 dws->cur_chip = NULL;
740 dws->prev_chip = NULL;
741 spin_unlock_irqrestore(&dws->lock, flags);
742
743 queue_work(dws->workqueue, &dws->pump_messages);
744
745 return 0;
746 }
747
stop_queue(struct dw_spi * dws)748 static int stop_queue(struct dw_spi *dws)
749 {
750 unsigned long flags;
751 unsigned limit = 50;
752 int status = 0;
753
754 spin_lock_irqsave(&dws->lock, flags);
755 dws->run = QUEUE_STOPPED;
756 while ((!list_empty(&dws->queue) || dws->busy) && limit--) {
757 spin_unlock_irqrestore(&dws->lock, flags);
758 msleep(10);
759 spin_lock_irqsave(&dws->lock, flags);
760 }
761
762 if (!list_empty(&dws->queue) || dws->busy)
763 status = -EBUSY;
764 spin_unlock_irqrestore(&dws->lock, flags);
765
766 return status;
767 }
768
destroy_queue(struct dw_spi * dws)769 static int destroy_queue(struct dw_spi *dws)
770 {
771 int status;
772
773 status = stop_queue(dws);
774 if (status != 0)
775 return status;
776 destroy_workqueue(dws->workqueue);
777 return 0;
778 }
779
780 /* Restart the controller, disable all interrupts, clean rx fifo */
spi_hw_init(struct dw_spi * dws)781 static void spi_hw_init(struct dw_spi *dws)
782 {
783 spi_enable_chip(dws, 0);
784 spi_mask_intr(dws, 0xff);
785 spi_enable_chip(dws, 1);
786
787 /*
788 * Try to detect the FIFO depth if not set by interface driver,
789 * the depth could be from 2 to 256 from HW spec
790 */
791 if (!dws->fifo_len) {
792 u32 fifo;
793 for (fifo = 2; fifo <= 257; fifo++) {
794 dw_writew(dws, DW_SPI_TXFLTR, fifo);
795 if (fifo != dw_readw(dws, DW_SPI_TXFLTR))
796 break;
797 }
798
799 dws->fifo_len = (fifo == 257) ? 0 : fifo;
800 dw_writew(dws, DW_SPI_TXFLTR, 0);
801 }
802 }
803
dw_spi_add_host(struct dw_spi * dws)804 int __devinit dw_spi_add_host(struct dw_spi *dws)
805 {
806 struct spi_master *master;
807 int ret;
808
809 BUG_ON(dws == NULL);
810
811 master = spi_alloc_master(dws->parent_dev, 0);
812 if (!master) {
813 ret = -ENOMEM;
814 goto exit;
815 }
816
817 dws->master = master;
818 dws->type = SSI_MOTO_SPI;
819 dws->prev_chip = NULL;
820 dws->dma_inited = 0;
821 dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
822 snprintf(dws->name, sizeof(dws->name), "dw_spi%d",
823 dws->bus_num);
824
825 ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED,
826 dws->name, dws);
827 if (ret < 0) {
828 dev_err(&master->dev, "can not get IRQ\n");
829 goto err_free_master;
830 }
831
832 master->mode_bits = SPI_CPOL | SPI_CPHA;
833 master->bus_num = dws->bus_num;
834 master->num_chipselect = dws->num_cs;
835 master->cleanup = dw_spi_cleanup;
836 master->setup = dw_spi_setup;
837 master->transfer = dw_spi_transfer;
838
839 /* Basic HW init */
840 spi_hw_init(dws);
841
842 if (dws->dma_ops && dws->dma_ops->dma_init) {
843 ret = dws->dma_ops->dma_init(dws);
844 if (ret) {
845 dev_warn(&master->dev, "DMA init failed\n");
846 dws->dma_inited = 0;
847 }
848 }
849
850 /* Initial and start queue */
851 ret = init_queue(dws);
852 if (ret) {
853 dev_err(&master->dev, "problem initializing queue\n");
854 goto err_diable_hw;
855 }
856 ret = start_queue(dws);
857 if (ret) {
858 dev_err(&master->dev, "problem starting queue\n");
859 goto err_diable_hw;
860 }
861
862 spi_master_set_devdata(master, dws);
863 ret = spi_register_master(master);
864 if (ret) {
865 dev_err(&master->dev, "problem registering spi master\n");
866 goto err_queue_alloc;
867 }
868
869 mrst_spi_debugfs_init(dws);
870 return 0;
871
872 err_queue_alloc:
873 destroy_queue(dws);
874 if (dws->dma_ops && dws->dma_ops->dma_exit)
875 dws->dma_ops->dma_exit(dws);
876 err_diable_hw:
877 spi_enable_chip(dws, 0);
878 free_irq(dws->irq, dws);
879 err_free_master:
880 spi_master_put(master);
881 exit:
882 return ret;
883 }
884 EXPORT_SYMBOL_GPL(dw_spi_add_host);
885
dw_spi_remove_host(struct dw_spi * dws)886 void __devexit dw_spi_remove_host(struct dw_spi *dws)
887 {
888 int status = 0;
889
890 if (!dws)
891 return;
892 mrst_spi_debugfs_remove(dws);
893
894 /* Remove the queue */
895 status = destroy_queue(dws);
896 if (status != 0)
897 dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
898 "complete, message memory not freed\n");
899
900 if (dws->dma_ops && dws->dma_ops->dma_exit)
901 dws->dma_ops->dma_exit(dws);
902 spi_enable_chip(dws, 0);
903 /* Disable clk */
904 spi_set_clk(dws, 0);
905 free_irq(dws->irq, dws);
906
907 /* Disconnect from the SPI framework */
908 spi_unregister_master(dws->master);
909 }
910 EXPORT_SYMBOL_GPL(dw_spi_remove_host);
911
dw_spi_suspend_host(struct dw_spi * dws)912 int dw_spi_suspend_host(struct dw_spi *dws)
913 {
914 int ret = 0;
915
916 ret = stop_queue(dws);
917 if (ret)
918 return ret;
919 spi_enable_chip(dws, 0);
920 spi_set_clk(dws, 0);
921 return ret;
922 }
923 EXPORT_SYMBOL_GPL(dw_spi_suspend_host);
924
dw_spi_resume_host(struct dw_spi * dws)925 int dw_spi_resume_host(struct dw_spi *dws)
926 {
927 int ret;
928
929 spi_hw_init(dws);
930 ret = start_queue(dws);
931 if (ret)
932 dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
933 return ret;
934 }
935 EXPORT_SYMBOL_GPL(dw_spi_resume_host);
936
937 MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
938 MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
939 MODULE_LICENSE("GPL v2");
940