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16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/interrupt.h>
19#include <linux/errno.h>
20#include <linux/platform_device.h>
21#include <linux/sched.h>
22#include <linux/delay.h>
23#include <linux/io.h>
24#include <linux/clk.h>
25#include <linux/err.h>
26#include <linux/spi/spi.h>
27#include <linux/spi/spi_bitbang.h>
28#include <linux/pm_runtime.h>
29#include <linux/of.h>
30#include <linux/of_device.h>
31
32#define DRIVER_NAME "fsl-dspi"
33
34#define TRAN_STATE_RX_VOID 0x01
35#define TRAN_STATE_TX_VOID 0x02
36#define TRAN_STATE_WORD_ODD_NUM 0x04
37
38#define DSPI_FIFO_SIZE 4
39
40#define SPI_MCR 0x00
41#define SPI_MCR_MASTER (1 << 31)
42#define SPI_MCR_PCSIS (0x3F << 16)
43#define SPI_MCR_CLR_TXF (1 << 11)
44#define SPI_MCR_CLR_RXF (1 << 10)
45
46#define SPI_TCR 0x08
47
48#define SPI_CTAR(x) (0x0c + (x * 4))
49#define SPI_CTAR_FMSZ(x) (((x) & 0x0000000f) << 27)
50#define SPI_CTAR_CPOL(x) ((x) << 26)
51#define SPI_CTAR_CPHA(x) ((x) << 25)
52#define SPI_CTAR_LSBFE(x) ((x) << 24)
53#define SPI_CTAR_PCSSCR(x) (((x) & 0x00000003) << 22)
54#define SPI_CTAR_PASC(x) (((x) & 0x00000003) << 20)
55#define SPI_CTAR_PDT(x) (((x) & 0x00000003) << 18)
56#define SPI_CTAR_PBR(x) (((x) & 0x00000003) << 16)
57#define SPI_CTAR_CSSCK(x) (((x) & 0x0000000f) << 12)
58#define SPI_CTAR_ASC(x) (((x) & 0x0000000f) << 8)
59#define SPI_CTAR_DT(x) (((x) & 0x0000000f) << 4)
60#define SPI_CTAR_BR(x) ((x) & 0x0000000f)
61
62#define SPI_CTAR0_SLAVE 0x0c
63
64#define SPI_SR 0x2c
65#define SPI_SR_EOQF 0x10000000
66
67#define SPI_RSER 0x30
68#define SPI_RSER_EOQFE 0x10000000
69
70#define SPI_PUSHR 0x34
71#define SPI_PUSHR_CONT (1 << 31)
72#define SPI_PUSHR_CTAS(x) (((x) & 0x00000007) << 28)
73#define SPI_PUSHR_EOQ (1 << 27)
74#define SPI_PUSHR_CTCNT (1 << 26)
75#define SPI_PUSHR_PCS(x) (((1 << x) & 0x0000003f) << 16)
76#define SPI_PUSHR_TXDATA(x) ((x) & 0x0000ffff)
77
78#define SPI_PUSHR_SLAVE 0x34
79
80#define SPI_POPR 0x38
81#define SPI_POPR_RXDATA(x) ((x) & 0x0000ffff)
82
83#define SPI_TXFR0 0x3c
84#define SPI_TXFR1 0x40
85#define SPI_TXFR2 0x44
86#define SPI_TXFR3 0x48
87#define SPI_RXFR0 0x7c
88#define SPI_RXFR1 0x80
89#define SPI_RXFR2 0x84
90#define SPI_RXFR3 0x88
91
92#define SPI_FRAME_BITS(bits) SPI_CTAR_FMSZ((bits) - 1)
93#define SPI_FRAME_BITS_MASK SPI_CTAR_FMSZ(0xf)
94#define SPI_FRAME_BITS_16 SPI_CTAR_FMSZ(0xf)
95#define SPI_FRAME_BITS_8 SPI_CTAR_FMSZ(0x7)
96
97#define SPI_CS_INIT 0x01
98#define SPI_CS_ASSERT 0x02
99#define SPI_CS_DROP 0x04
100
101struct chip_data {
102 u32 mcr_val;
103 u32 ctar_val;
104 u16 void_write_data;
105};
106
107struct fsl_dspi {
108 struct spi_bitbang bitbang;
109 struct platform_device *pdev;
110
111 void __iomem *base;
112 int irq;
113 struct clk *clk;
114
115 struct spi_transfer *cur_transfer;
116 struct chip_data *cur_chip;
117 size_t len;
118 void *tx;
119 void *tx_end;
120 void *rx;
121 void *rx_end;
122 char dataflags;
123 u8 cs;
124 u16 void_write_data;
125
126 wait_queue_head_t waitq;
127 u32 waitflags;
128};
129
130static inline int is_double_byte_mode(struct fsl_dspi *dspi)
131{
132 return ((readl(dspi->base + SPI_CTAR(dspi->cs)) & SPI_FRAME_BITS_MASK)
133 == SPI_FRAME_BITS(8)) ? 0 : 1;
134}
135
136static void set_bit_mode(struct fsl_dspi *dspi, unsigned char bits)
137{
138 u32 temp;
139
140 temp = readl(dspi->base + SPI_CTAR(dspi->cs));
141 temp &= ~SPI_FRAME_BITS_MASK;
142 temp |= SPI_FRAME_BITS(bits);
143 writel(temp, dspi->base + SPI_CTAR(dspi->cs));
144}
145
146static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
147 unsigned long clkrate)
148{
149
150 int pbr_tbl[4] = {2, 3, 5, 7};
151 int brs[16] = { 2, 4, 6, 8,
152 16, 32, 64, 128,
153 256, 512, 1024, 2048,
154 4096, 8192, 16384, 32768 };
155 int temp, i = 0, j = 0;
156
157 temp = clkrate / 2 / speed_hz;
158
159 for (i = 0; i < ARRAY_SIZE(pbr_tbl); i++)
160 for (j = 0; j < ARRAY_SIZE(brs); j++) {
161 if (pbr_tbl[i] * brs[j] >= temp) {
162 *pbr = i;
163 *br = j;
164 return;
165 }
166 }
167
168 pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld\
169 ,we use the max prescaler value.\n", speed_hz, clkrate);
170 *pbr = ARRAY_SIZE(pbr_tbl) - 1;
171 *br = ARRAY_SIZE(brs) - 1;
172}
173
174static int dspi_transfer_write(struct fsl_dspi *dspi)
175{
176 int tx_count = 0;
177 int tx_word;
178 u16 d16;
179 u8 d8;
180 u32 dspi_pushr = 0;
181 int first = 1;
182
183 tx_word = is_double_byte_mode(dspi);
184
185
186
187
188
189 if (tx_word && (dspi->len == 1)) {
190 dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
191 set_bit_mode(dspi, 8);
192 tx_word = 0;
193 }
194
195 while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) {
196 if (tx_word) {
197 if (dspi->len == 1)
198 break;
199
200 if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
201 d16 = *(u16 *)dspi->tx;
202 dspi->tx += 2;
203 } else {
204 d16 = dspi->void_write_data;
205 }
206
207 dspi_pushr = SPI_PUSHR_TXDATA(d16) |
208 SPI_PUSHR_PCS(dspi->cs) |
209 SPI_PUSHR_CTAS(dspi->cs) |
210 SPI_PUSHR_CONT;
211
212 dspi->len -= 2;
213 } else {
214 if (!(dspi->dataflags & TRAN_STATE_TX_VOID)) {
215
216 d8 = *(u8 *)dspi->tx;
217 dspi->tx++;
218 } else {
219 d8 = (u8)dspi->void_write_data;
220 }
221
222 dspi_pushr = SPI_PUSHR_TXDATA(d8) |
223 SPI_PUSHR_PCS(dspi->cs) |
224 SPI_PUSHR_CTAS(dspi->cs) |
225 SPI_PUSHR_CONT;
226
227 dspi->len--;
228 }
229
230 if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) {
231
232 dspi_pushr |= SPI_PUSHR_EOQ;
233 } else if (tx_word && (dspi->len == 1))
234 dspi_pushr |= SPI_PUSHR_EOQ;
235
236 if (first) {
237 first = 0;
238 dspi_pushr |= SPI_PUSHR_CTCNT;
239 }
240
241 writel(dspi_pushr, dspi->base + SPI_PUSHR);
242 tx_count++;
243 }
244
245 return tx_count * (tx_word + 1);
246}
247
248static int dspi_transfer_read(struct fsl_dspi *dspi)
249{
250 int rx_count = 0;
251 int rx_word = is_double_byte_mode(dspi);
252 u16 d;
253 while ((dspi->rx < dspi->rx_end)
254 && (rx_count < DSPI_FIFO_SIZE)) {
255 if (rx_word) {
256 if ((dspi->rx_end - dspi->rx) == 1)
257 break;
258
259 d = SPI_POPR_RXDATA(readl(dspi->base + SPI_POPR));
260
261 if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
262 *(u16 *)dspi->rx = d;
263 dspi->rx += 2;
264
265 } else {
266 d = SPI_POPR_RXDATA(readl(dspi->base + SPI_POPR));
267 if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
268 *(u8 *)dspi->rx = d;
269 dspi->rx++;
270 }
271 rx_count++;
272 }
273
274 return rx_count;
275}
276
277static int dspi_txrx_transfer(struct spi_device *spi, struct spi_transfer *t)
278{
279 struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
280 dspi->cur_transfer = t;
281 dspi->cur_chip = spi_get_ctldata(spi);
282 dspi->cs = spi->chip_select;
283 dspi->void_write_data = dspi->cur_chip->void_write_data;
284
285 dspi->dataflags = 0;
286 dspi->tx = (void *)t->tx_buf;
287 dspi->tx_end = dspi->tx + t->len;
288 dspi->rx = t->rx_buf;
289 dspi->rx_end = dspi->rx + t->len;
290 dspi->len = t->len;
291
292 if (!dspi->rx)
293 dspi->dataflags |= TRAN_STATE_RX_VOID;
294
295 if (!dspi->tx)
296 dspi->dataflags |= TRAN_STATE_TX_VOID;
297
298 writel(dspi->cur_chip->mcr_val, dspi->base + SPI_MCR);
299 writel(dspi->cur_chip->ctar_val, dspi->base + SPI_CTAR(dspi->cs));
300 writel(SPI_RSER_EOQFE, dspi->base + SPI_RSER);
301
302 if (t->speed_hz)
303 writel(dspi->cur_chip->ctar_val,
304 dspi->base + SPI_CTAR(dspi->cs));
305
306 dspi_transfer_write(dspi);
307
308 if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
309 dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
310 dspi->waitflags = 0;
311
312 return t->len - dspi->len;
313}
314
315static void dspi_chipselect(struct spi_device *spi, int value)
316{
317 struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
318 u32 pushr = readl(dspi->base + SPI_PUSHR);
319
320 switch (value) {
321 case BITBANG_CS_ACTIVE:
322 pushr |= SPI_PUSHR_CONT;
323 case BITBANG_CS_INACTIVE:
324 pushr &= ~SPI_PUSHR_CONT;
325 }
326
327 writel(pushr, dspi->base + SPI_PUSHR);
328}
329
330static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
331{
332 struct chip_data *chip;
333 struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
334 unsigned char br = 0, pbr = 0, fmsz = 0;
335
336
337 chip = spi_get_ctldata(spi);
338 if (chip == NULL) {
339 chip = kcalloc(1, sizeof(struct chip_data), GFP_KERNEL);
340 if (!chip)
341 return -ENOMEM;
342 }
343
344 chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS |
345 SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF;
346 if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) {
347 fmsz = spi->bits_per_word - 1;
348 } else {
349 pr_err("Invalid wordsize\n");
350 kfree(chip);
351 return -ENODEV;
352 }
353
354 chip->void_write_data = 0;
355
356 hz_to_spi_baud(&pbr, &br,
357 spi->max_speed_hz, clk_get_rate(dspi->clk));
358
359 chip->ctar_val = SPI_CTAR_FMSZ(fmsz)
360 | SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0)
361 | SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0)
362 | SPI_CTAR_LSBFE(spi->mode & SPI_LSB_FIRST ? 1 : 0)
363 | SPI_CTAR_PBR(pbr)
364 | SPI_CTAR_BR(br);
365
366 spi_set_ctldata(spi, chip);
367
368 return 0;
369}
370
371static int dspi_setup(struct spi_device *spi)
372{
373 if (!spi->max_speed_hz)
374 return -EINVAL;
375
376 if (!spi->bits_per_word)
377 spi->bits_per_word = 8;
378
379 return dspi_setup_transfer(spi, NULL);
380}
381
382static irqreturn_t dspi_interrupt(int irq, void *dev_id)
383{
384 struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
385
386 writel(SPI_SR_EOQF, dspi->base + SPI_SR);
387
388 dspi_transfer_read(dspi);
389
390 if (!dspi->len) {
391 if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM)
392 set_bit_mode(dspi, 16);
393 dspi->waitflags = 1;
394 wake_up_interruptible(&dspi->waitq);
395 } else {
396 dspi_transfer_write(dspi);
397
398 return IRQ_HANDLED;
399 }
400
401 return IRQ_HANDLED;
402}
403
404static struct of_device_id fsl_dspi_dt_ids[] = {
405 { .compatible = "fsl,vf610-dspi", .data = NULL, },
406 { }
407};
408MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);
409
410#ifdef CONFIG_PM_SLEEP
411static int dspi_suspend(struct device *dev)
412{
413 struct spi_master *master = dev_get_drvdata(dev);
414 struct fsl_dspi *dspi = spi_master_get_devdata(master);
415
416 spi_master_suspend(master);
417 clk_disable_unprepare(dspi->clk);
418
419 return 0;
420}
421
422static int dspi_resume(struct device *dev)
423{
424
425 struct spi_master *master = dev_get_drvdata(dev);
426 struct fsl_dspi *dspi = spi_master_get_devdata(master);
427
428 clk_prepare_enable(dspi->clk);
429 spi_master_resume(master);
430
431 return 0;
432}
433#endif
434
435static const struct dev_pm_ops dspi_pm = {
436 SET_SYSTEM_SLEEP_PM_OPS(dspi_suspend, dspi_resume)
437};
438
439static int dspi_probe(struct platform_device *pdev)
440{
441 struct device_node *np = pdev->dev.of_node;
442 struct spi_master *master;
443 struct fsl_dspi *dspi;
444 struct resource *res;
445 int ret = 0, cs_num, bus_num;
446
447 master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
448 if (!master)
449 return -ENOMEM;
450
451 dspi = spi_master_get_devdata(master);
452 dspi->pdev = pdev;
453 dspi->bitbang.master = master;
454 dspi->bitbang.chipselect = dspi_chipselect;
455 dspi->bitbang.setup_transfer = dspi_setup_transfer;
456 dspi->bitbang.txrx_bufs = dspi_txrx_transfer;
457 dspi->bitbang.master->setup = dspi_setup;
458 dspi->bitbang.master->dev.of_node = pdev->dev.of_node;
459
460 master->mode_bits = SPI_CPOL | SPI_CPHA;
461 master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) |
462 SPI_BPW_MASK(16);
463
464 ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
465 if (ret < 0) {
466 dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
467 goto out_master_put;
468 }
469 master->num_chipselect = cs_num;
470
471 ret = of_property_read_u32(np, "bus-num", &bus_num);
472 if (ret < 0) {
473 dev_err(&pdev->dev, "can't get bus-num\n");
474 goto out_master_put;
475 }
476 master->bus_num = bus_num;
477
478 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
479 dspi->base = devm_ioremap_resource(&pdev->dev, res);
480 if (IS_ERR(dspi->base)) {
481 ret = PTR_ERR(dspi->base);
482 goto out_master_put;
483 }
484
485 dspi->irq = platform_get_irq(pdev, 0);
486 if (dspi->irq < 0) {
487 dev_err(&pdev->dev, "can't get platform irq\n");
488 ret = dspi->irq;
489 goto out_master_put;
490 }
491
492 ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0,
493 pdev->name, dspi);
494 if (ret < 0) {
495 dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
496 goto out_master_put;
497 }
498
499 dspi->clk = devm_clk_get(&pdev->dev, "dspi");
500 if (IS_ERR(dspi->clk)) {
501 ret = PTR_ERR(dspi->clk);
502 dev_err(&pdev->dev, "unable to get clock\n");
503 goto out_master_put;
504 }
505 clk_prepare_enable(dspi->clk);
506
507 init_waitqueue_head(&dspi->waitq);
508 platform_set_drvdata(pdev, dspi);
509
510 ret = spi_bitbang_start(&dspi->bitbang);
511 if (ret != 0) {
512 dev_err(&pdev->dev, "Problem registering DSPI master\n");
513 goto out_clk_put;
514 }
515
516 pr_info(KERN_INFO "Freescale DSPI master initialized\n");
517 return ret;
518
519out_clk_put:
520 clk_disable_unprepare(dspi->clk);
521out_master_put:
522 spi_master_put(master);
523
524 return ret;
525}
526
527static int dspi_remove(struct platform_device *pdev)
528{
529 struct fsl_dspi *dspi = platform_get_drvdata(pdev);
530
531
532 spi_bitbang_stop(&dspi->bitbang);
533 clk_disable_unprepare(dspi->clk);
534 spi_master_put(dspi->bitbang.master);
535
536 return 0;
537}
538
539static struct platform_driver fsl_dspi_driver = {
540 .driver.name = DRIVER_NAME,
541 .driver.of_match_table = fsl_dspi_dt_ids,
542 .driver.owner = THIS_MODULE,
543 .driver.pm = &dspi_pm,
544 .probe = dspi_probe,
545 .remove = dspi_remove,
546};
547module_platform_driver(fsl_dspi_driver);
548
549MODULE_DESCRIPTION("Freescale DSPI Controller Driver");
550MODULE_LICENSE("GPL");
551MODULE_ALIAS("platform:" DRIVER_NAME);
552
