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16#include <linux/clk.h>
17#include <linux/delay.h>
18#include <linux/err.h>
19#include <linux/errno.h>
20#include <linux/interrupt.h>
21#include <linux/io.h>
22#include <linux/kernel.h>
23#include <linux/math64.h>
24#include <linux/module.h>
25#include <linux/of.h>
26#include <linux/of_device.h>
27#include <linux/platform_device.h>
28#include <linux/pm_runtime.h>
29#include <linux/regmap.h>
30#include <linux/sched.h>
31#include <linux/spi/spi.h>
32#include <linux/spi/spi_bitbang.h>
33#include <linux/time.h>
34
35#define DRIVER_NAME "fsl-dspi"
36
37#define TRAN_STATE_RX_VOID 0x01
38#define TRAN_STATE_TX_VOID 0x02
39#define TRAN_STATE_WORD_ODD_NUM 0x04
40
41#define DSPI_FIFO_SIZE 4
42
43#define SPI_MCR 0x00
44#define SPI_MCR_MASTER (1 << 31)
45#define SPI_MCR_PCSIS (0x3F << 16)
46#define SPI_MCR_CLR_TXF (1 << 11)
47#define SPI_MCR_CLR_RXF (1 << 10)
48
49#define SPI_TCR 0x08
50
51#define SPI_CTAR(x) (0x0c + (((x) & 0x3) * 4))
52#define SPI_CTAR_FMSZ(x) (((x) & 0x0000000f) << 27)
53#define SPI_CTAR_CPOL(x) ((x) << 26)
54#define SPI_CTAR_CPHA(x) ((x) << 25)
55#define SPI_CTAR_LSBFE(x) ((x) << 24)
56#define SPI_CTAR_PCSSCK(x) (((x) & 0x00000003) << 22)
57#define SPI_CTAR_PASC(x) (((x) & 0x00000003) << 20)
58#define SPI_CTAR_PDT(x) (((x) & 0x00000003) << 18)
59#define SPI_CTAR_PBR(x) (((x) & 0x00000003) << 16)
60#define SPI_CTAR_CSSCK(x) (((x) & 0x0000000f) << 12)
61#define SPI_CTAR_ASC(x) (((x) & 0x0000000f) << 8)
62#define SPI_CTAR_DT(x) (((x) & 0x0000000f) << 4)
63#define SPI_CTAR_BR(x) ((x) & 0x0000000f)
64#define SPI_CTAR_SCALE_BITS 0xf
65
66#define SPI_CTAR0_SLAVE 0x0c
67
68#define SPI_SR 0x2c
69#define SPI_SR_EOQF 0x10000000
70
71#define SPI_RSER 0x30
72#define SPI_RSER_EOQFE 0x10000000
73
74#define SPI_PUSHR 0x34
75#define SPI_PUSHR_CONT (1 << 31)
76#define SPI_PUSHR_CTAS(x) (((x) & 0x00000003) << 28)
77#define SPI_PUSHR_EOQ (1 << 27)
78#define SPI_PUSHR_CTCNT (1 << 26)
79#define SPI_PUSHR_PCS(x) (((1 << x) & 0x0000003f) << 16)
80#define SPI_PUSHR_TXDATA(x) ((x) & 0x0000ffff)
81
82#define SPI_PUSHR_SLAVE 0x34
83
84#define SPI_POPR 0x38
85#define SPI_POPR_RXDATA(x) ((x) & 0x0000ffff)
86
87#define SPI_TXFR0 0x3c
88#define SPI_TXFR1 0x40
89#define SPI_TXFR2 0x44
90#define SPI_TXFR3 0x48
91#define SPI_RXFR0 0x7c
92#define SPI_RXFR1 0x80
93#define SPI_RXFR2 0x84
94#define SPI_RXFR3 0x88
95
96#define SPI_FRAME_BITS(bits) SPI_CTAR_FMSZ((bits) - 1)
97#define SPI_FRAME_BITS_MASK SPI_CTAR_FMSZ(0xf)
98#define SPI_FRAME_BITS_16 SPI_CTAR_FMSZ(0xf)
99#define SPI_FRAME_BITS_8 SPI_CTAR_FMSZ(0x7)
100
101#define SPI_CS_INIT 0x01
102#define SPI_CS_ASSERT 0x02
103#define SPI_CS_DROP 0x04
104
105struct chip_data {
106 u32 mcr_val;
107 u32 ctar_val;
108 u16 void_write_data;
109};
110
111struct fsl_dspi {
112 struct spi_master *master;
113 struct platform_device *pdev;
114
115 struct regmap *regmap;
116 int irq;
117 struct clk *clk;
118
119 struct spi_transfer *cur_transfer;
120 struct spi_message *cur_msg;
121 struct chip_data *cur_chip;
122 size_t len;
123 void *tx;
124 void *tx_end;
125 void *rx;
126 void *rx_end;
127 char dataflags;
128 u8 cs;
129 u16 void_write_data;
130 u32 cs_change;
131
132 wait_queue_head_t waitq;
133 u32 waitflags;
134};
135
136static inline int is_double_byte_mode(struct fsl_dspi *dspi)
137{
138 unsigned int val;
139
140 regmap_read(dspi->regmap, SPI_CTAR(dspi->cs), &val);
141
142 return ((val & SPI_FRAME_BITS_MASK) == SPI_FRAME_BITS(8)) ? 0 : 1;
143}
144
145static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
146 unsigned long clkrate)
147{
148
149 int pbr_tbl[4] = {2, 3, 5, 7};
150 int brs[16] = { 2, 4, 6, 8,
151 16, 32, 64, 128,
152 256, 512, 1024, 2048,
153 4096, 8192, 16384, 32768 };
154 int scale_needed, scale, minscale = INT_MAX;
155 int i, j;
156
157 scale_needed = clkrate / speed_hz;
158 if (clkrate % speed_hz)
159 scale_needed++;
160
161 for (i = 0; i < ARRAY_SIZE(brs); i++)
162 for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) {
163 scale = brs[i] * pbr_tbl[j];
164 if (scale >= scale_needed) {
165 if (scale < minscale) {
166 minscale = scale;
167 *br = i;
168 *pbr = j;
169 }
170 break;
171 }
172 }
173
174 if (minscale == INT_MAX) {
175 pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n",
176 speed_hz, clkrate);
177 *pbr = ARRAY_SIZE(pbr_tbl) - 1;
178 *br = ARRAY_SIZE(brs) - 1;
179 }
180}
181
182static void ns_delay_scale(char *psc, char *sc, int delay_ns,
183 unsigned long clkrate)
184{
185 int pscale_tbl[4] = {1, 3, 5, 7};
186 int scale_needed, scale, minscale = INT_MAX;
187 int i, j;
188 u32 remainder;
189
190 scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC,
191 &remainder);
192 if (remainder)
193 scale_needed++;
194
195 for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++)
196 for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) {
197 scale = pscale_tbl[i] * (2 << j);
198 if (scale >= scale_needed) {
199 if (scale < minscale) {
200 minscale = scale;
201 *psc = i;
202 *sc = j;
203 }
204 break;
205 }
206 }
207
208 if (minscale == INT_MAX) {
209 pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value",
210 delay_ns, clkrate);
211 *psc = ARRAY_SIZE(pscale_tbl) - 1;
212 *sc = SPI_CTAR_SCALE_BITS;
213 }
214}
215
216static int dspi_transfer_write(struct fsl_dspi *dspi)
217{
218 int tx_count = 0;
219 int tx_word;
220 u16 d16;
221 u8 d8;
222 u32 dspi_pushr = 0;
223 int first = 1;
224
225 tx_word = is_double_byte_mode(dspi);
226
227
228
229
230
231 if (tx_word && (dspi->len == 1)) {
232 dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
233 regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
234 SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
235 tx_word = 0;
236 }
237
238 while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) {
239 if (tx_word) {
240 if (dspi->len == 1)
241 break;
242
243 if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
244 d16 = *(u16 *)dspi->tx;
245 dspi->tx += 2;
246 } else {
247 d16 = dspi->void_write_data;
248 }
249
250 dspi_pushr = SPI_PUSHR_TXDATA(d16) |
251 SPI_PUSHR_PCS(dspi->cs) |
252 SPI_PUSHR_CTAS(dspi->cs) |
253 SPI_PUSHR_CONT;
254
255 dspi->len -= 2;
256 } else {
257 if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
258
259 d8 = *(u8 *)dspi->tx;
260 dspi->tx++;
261 } else {
262 d8 = (u8)dspi->void_write_data;
263 }
264
265 dspi_pushr = SPI_PUSHR_TXDATA(d8) |
266 SPI_PUSHR_PCS(dspi->cs) |
267 SPI_PUSHR_CTAS(dspi->cs) |
268 SPI_PUSHR_CONT;
269
270 dspi->len--;
271 }
272
273 if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) {
274
275 dspi_pushr |= SPI_PUSHR_EOQ;
276 if ((dspi->cs_change) && (!dspi->len))
277 dspi_pushr &= ~SPI_PUSHR_CONT;
278 } else if (tx_word && (dspi->len == 1))
279 dspi_pushr |= SPI_PUSHR_EOQ;
280
281 if (first) {
282 first = 0;
283 dspi_pushr |= SPI_PUSHR_CTCNT;
284 }
285
286 regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
287
288 tx_count++;
289 }
290
291 return tx_count * (tx_word + 1);
292}
293
294static int dspi_transfer_read(struct fsl_dspi *dspi)
295{
296 int rx_count = 0;
297 int rx_word = is_double_byte_mode(dspi);
298 u16 d;
299
300 while ((dspi->rx < dspi->rx_end)
301 && (rx_count < DSPI_FIFO_SIZE)) {
302 if (rx_word) {
303 unsigned int val;
304
305 if ((dspi->rx_end - dspi->rx) == 1)
306 break;
307
308 regmap_read(dspi->regmap, SPI_POPR, &val);
309 d = SPI_POPR_RXDATA(val);
310
311 if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
312 *(u16 *)dspi->rx = d;
313 dspi->rx += 2;
314
315 } else {
316 unsigned int val;
317
318 regmap_read(dspi->regmap, SPI_POPR, &val);
319 d = SPI_POPR_RXDATA(val);
320 if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
321 *(u8 *)dspi->rx = d;
322 dspi->rx++;
323 }
324 rx_count++;
325 }
326
327 return rx_count;
328}
329
330static int dspi_transfer_one_message(struct spi_master *master,
331 struct spi_message *message)
332{
333 struct fsl_dspi *dspi = spi_master_get_devdata(master);
334 struct spi_device *spi = message->spi;
335 struct spi_transfer *transfer;
336 int status = 0;
337 message->actual_length = 0;
338
339 list_for_each_entry(transfer, &message->transfers, transfer_list) {
340 dspi->cur_transfer = transfer;
341 dspi->cur_msg = message;
342 dspi->cur_chip = spi_get_ctldata(spi);
343 dspi->cs = spi->chip_select;
344 if (dspi->cur_transfer->transfer_list.next
345 == &dspi->cur_msg->transfers)
346 transfer->cs_change = 1;
347 dspi->cs_change = transfer->cs_change;
348 dspi->void_write_data = dspi->cur_chip->void_write_data;
349
350 dspi->dataflags = 0;
351 dspi->tx = (void *)transfer->tx_buf;
352 dspi->tx_end = dspi->tx + transfer->len;
353 dspi->rx = transfer->rx_buf;
354 dspi->rx_end = dspi->rx + transfer->len;
355 dspi->len = transfer->len;
356
357 if (!dspi->rx)
358 dspi->dataflags |= TRAN_STATE_RX_VOID;
359
360 if (!dspi->tx)
361 dspi->dataflags |= TRAN_STATE_TX_VOID;
362
363 regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val);
364 regmap_update_bits(dspi->regmap, SPI_MCR,
365 SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
366 SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);
367 regmap_write(dspi->regmap, SPI_CTAR(dspi->cs),
368 dspi->cur_chip->ctar_val);
369 if (transfer->speed_hz)
370 regmap_write(dspi->regmap, SPI_CTAR(dspi->cs),
371 dspi->cur_chip->ctar_val);
372
373 regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
374 message->actual_length += dspi_transfer_write(dspi);
375
376 if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
377 dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
378 dspi->waitflags = 0;
379
380 if (transfer->delay_usecs)
381 udelay(transfer->delay_usecs);
382 }
383
384 message->status = status;
385 spi_finalize_current_message(master);
386
387 return status;
388}
389
390static int dspi_setup(struct spi_device *spi)
391{
392 struct chip_data *chip;
393 struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
394 u32 cs_sck_delay = 0, sck_cs_delay = 0;
395 unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0;
396 unsigned char pasc = 0, asc = 0, fmsz = 0;
397 unsigned long clkrate;
398
399 if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) {
400 fmsz = spi->bits_per_word - 1;
401 } else {
402 pr_err("Invalid wordsize\n");
403 return -ENODEV;
404 }
405
406
407 chip = spi_get_ctldata(spi);
408 if (chip == NULL) {
409 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
410 if (!chip)
411 return -ENOMEM;
412 }
413
414 of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay",
415 &cs_sck_delay);
416
417 of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay",
418 &sck_cs_delay);
419
420 chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS |
421 SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF;
422
423 chip->void_write_data = 0;
424
425 clkrate = clk_get_rate(dspi->clk);
426 hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate);
427
428
429 ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate);
430
431
432 ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate);
433
434 chip->ctar_val = SPI_CTAR_FMSZ(fmsz)
435 | SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0)
436 | SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0)
437 | SPI_CTAR_LSBFE(spi->mode & SPI_LSB_FIRST ? 1 : 0)
438 | SPI_CTAR_PCSSCK(pcssck)
439 | SPI_CTAR_CSSCK(cssck)
440 | SPI_CTAR_PASC(pasc)
441 | SPI_CTAR_ASC(asc)
442 | SPI_CTAR_PBR(pbr)
443 | SPI_CTAR_BR(br);
444
445 spi_set_ctldata(spi, chip);
446
447 return 0;
448}
449
450static void dspi_cleanup(struct spi_device *spi)
451{
452 struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
453
454 dev_dbg(&spi->dev, "spi_device %u.%u cleanup\n",
455 spi->master->bus_num, spi->chip_select);
456
457 kfree(chip);
458}
459
460static irqreturn_t dspi_interrupt(int irq, void *dev_id)
461{
462 struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
463
464 struct spi_message *msg = dspi->cur_msg;
465
466 regmap_write(dspi->regmap, SPI_SR, SPI_SR_EOQF);
467 dspi_transfer_read(dspi);
468
469 if (!dspi->len) {
470 if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM)
471 regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
472 SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(16));
473
474 dspi->waitflags = 1;
475 wake_up_interruptible(&dspi->waitq);
476 } else
477 msg->actual_length += dspi_transfer_write(dspi);
478
479 return IRQ_HANDLED;
480}
481
482static const struct of_device_id fsl_dspi_dt_ids[] = {
483 { .compatible = "fsl,vf610-dspi", .data = NULL, },
484 { }
485};
486MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);
487
488#ifdef CONFIG_PM_SLEEP
489static int dspi_suspend(struct device *dev)
490{
491 struct spi_master *master = dev_get_drvdata(dev);
492 struct fsl_dspi *dspi = spi_master_get_devdata(master);
493
494 spi_master_suspend(master);
495 clk_disable_unprepare(dspi->clk);
496
497 return 0;
498}
499
500static int dspi_resume(struct device *dev)
501{
502 struct spi_master *master = dev_get_drvdata(dev);
503 struct fsl_dspi *dspi = spi_master_get_devdata(master);
504
505 clk_prepare_enable(dspi->clk);
506 spi_master_resume(master);
507
508 return 0;
509}
510#endif
511
512static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume);
513
514static const struct regmap_config dspi_regmap_config = {
515 .reg_bits = 32,
516 .val_bits = 32,
517 .reg_stride = 4,
518 .max_register = 0x88,
519};
520
521static int dspi_probe(struct platform_device *pdev)
522{
523 struct device_node *np = pdev->dev.of_node;
524 struct spi_master *master;
525 struct fsl_dspi *dspi;
526 struct resource *res;
527 void __iomem *base;
528 int ret = 0, cs_num, bus_num;
529
530 master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
531 if (!master)
532 return -ENOMEM;
533
534 dspi = spi_master_get_devdata(master);
535 dspi->pdev = pdev;
536 dspi->master = master;
537
538 master->transfer = NULL;
539 master->setup = dspi_setup;
540 master->transfer_one_message = dspi_transfer_one_message;
541 master->dev.of_node = pdev->dev.of_node;
542
543 master->cleanup = dspi_cleanup;
544 master->mode_bits = SPI_CPOL | SPI_CPHA;
545 master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) |
546 SPI_BPW_MASK(16);
547
548 ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
549 if (ret < 0) {
550 dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
551 goto out_master_put;
552 }
553 master->num_chipselect = cs_num;
554
555 ret = of_property_read_u32(np, "bus-num", &bus_num);
556 if (ret < 0) {
557 dev_err(&pdev->dev, "can't get bus-num\n");
558 goto out_master_put;
559 }
560 master->bus_num = bus_num;
561
562 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
563 base = devm_ioremap_resource(&pdev->dev, res);
564 if (IS_ERR(base)) {
565 ret = PTR_ERR(base);
566 goto out_master_put;
567 }
568
569 dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dspi", base,
570 &dspi_regmap_config);
571 if (IS_ERR(dspi->regmap)) {
572 dev_err(&pdev->dev, "failed to init regmap: %ld\n",
573 PTR_ERR(dspi->regmap));
574 return PTR_ERR(dspi->regmap);
575 }
576
577 dspi->irq = platform_get_irq(pdev, 0);
578 if (dspi->irq < 0) {
579 dev_err(&pdev->dev, "can't get platform irq\n");
580 ret = dspi->irq;
581 goto out_master_put;
582 }
583
584 ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0,
585 pdev->name, dspi);
586 if (ret < 0) {
587 dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
588 goto out_master_put;
589 }
590
591 dspi->clk = devm_clk_get(&pdev->dev, "dspi");
592 if (IS_ERR(dspi->clk)) {
593 ret = PTR_ERR(dspi->clk);
594 dev_err(&pdev->dev, "unable to get clock\n");
595 goto out_master_put;
596 }
597 clk_prepare_enable(dspi->clk);
598
599 init_waitqueue_head(&dspi->waitq);
600 platform_set_drvdata(pdev, master);
601
602 ret = spi_register_master(master);
603 if (ret != 0) {
604 dev_err(&pdev->dev, "Problem registering DSPI master\n");
605 goto out_clk_put;
606 }
607
608 return ret;
609
610out_clk_put:
611 clk_disable_unprepare(dspi->clk);
612out_master_put:
613 spi_master_put(master);
614
615 return ret;
616}
617
618static int dspi_remove(struct platform_device *pdev)
619{
620 struct spi_master *master = platform_get_drvdata(pdev);
621 struct fsl_dspi *dspi = spi_master_get_devdata(master);
622
623
624 clk_disable_unprepare(dspi->clk);
625 spi_unregister_master(dspi->master);
626 spi_master_put(dspi->master);
627
628 return 0;
629}
630
631static struct platform_driver fsl_dspi_driver = {
632 .driver.name = DRIVER_NAME,
633 .driver.of_match_table = fsl_dspi_dt_ids,
634 .driver.owner = THIS_MODULE,
635 .driver.pm = &dspi_pm,
636 .probe = dspi_probe,
637 .remove = dspi_remove,
638};
639module_platform_driver(fsl_dspi_driver);
640
641MODULE_DESCRIPTION("Freescale DSPI Controller Driver");
642MODULE_LICENSE("GPL");
643MODULE_ALIAS("platform:" DRIVER_NAME);
644
