2 * drivers/spi/spi-fsl-dspi.c
4 * Copyright 2013 Freescale Semiconductor, Inc.
6 * Freescale DSPI driver
7 * This file contains a driver for the Freescale DSPI
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
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>
22 #include <linux/kernel.h>
23 #include <linux/math64.h>
24 #include <linux/module.h>
26 #include <linux/of_device.h>
27 #include <linux/pinctrl/consumer.h>
28 #include <linux/platform_device.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/regmap.h>
31 #include <linux/sched.h>
32 #include <linux/spi/spi.h>
33 #include <linux/spi/spi_bitbang.h>
34 #include <linux/time.h>
36 #define DRIVER_NAME "fsl-dspi"
38 #define TRAN_STATE_RX_VOID 0x01
39 #define TRAN_STATE_TX_VOID 0x02
40 #define TRAN_STATE_WORD_ODD_NUM 0x04
42 #define DSPI_FIFO_SIZE 4
45 #define SPI_MCR_MASTER (1 << 31)
46 #define SPI_MCR_PCSIS (0x3F << 16)
47 #define SPI_MCR_CLR_TXF (1 << 11)
48 #define SPI_MCR_CLR_RXF (1 << 10)
51 #define SPI_TCR_GET_TCNT(x) (((x) & 0xffff0000) >> 16)
53 #define SPI_CTAR(x) (0x0c + (((x) & 0x3) * 4))
54 #define SPI_CTAR_FMSZ(x) (((x) & 0x0000000f) << 27)
55 #define SPI_CTAR_CPOL(x) ((x) << 26)
56 #define SPI_CTAR_CPHA(x) ((x) << 25)
57 #define SPI_CTAR_LSBFE(x) ((x) << 24)
58 #define SPI_CTAR_PCSSCK(x) (((x) & 0x00000003) << 22)
59 #define SPI_CTAR_PASC(x) (((x) & 0x00000003) << 20)
60 #define SPI_CTAR_PDT(x) (((x) & 0x00000003) << 18)
61 #define SPI_CTAR_PBR(x) (((x) & 0x00000003) << 16)
62 #define SPI_CTAR_CSSCK(x) (((x) & 0x0000000f) << 12)
63 #define SPI_CTAR_ASC(x) (((x) & 0x0000000f) << 8)
64 #define SPI_CTAR_DT(x) (((x) & 0x0000000f) << 4)
65 #define SPI_CTAR_BR(x) ((x) & 0x0000000f)
66 #define SPI_CTAR_SCALE_BITS 0xf
68 #define SPI_CTAR0_SLAVE 0x0c
71 #define SPI_SR_EOQF 0x10000000
72 #define SPI_SR_TCFQF 0x80000000
75 #define SPI_RSER_EOQFE 0x10000000
76 #define SPI_RSER_TCFQE 0x80000000
78 #define SPI_PUSHR 0x34
79 #define SPI_PUSHR_CONT (1 << 31)
80 #define SPI_PUSHR_CTAS(x) (((x) & 0x00000003) << 28)
81 #define SPI_PUSHR_EOQ (1 << 27)
82 #define SPI_PUSHR_CTCNT (1 << 26)
83 #define SPI_PUSHR_PCS(x) (((1 << x) & 0x0000003f) << 16)
84 #define SPI_PUSHR_TXDATA(x) ((x) & 0x0000ffff)
86 #define SPI_PUSHR_SLAVE 0x34
89 #define SPI_POPR_RXDATA(x) ((x) & 0x0000ffff)
91 #define SPI_TXFR0 0x3c
92 #define SPI_TXFR1 0x40
93 #define SPI_TXFR2 0x44
94 #define SPI_TXFR3 0x48
95 #define SPI_RXFR0 0x7c
96 #define SPI_RXFR1 0x80
97 #define SPI_RXFR2 0x84
98 #define SPI_RXFR3 0x88
100 #define SPI_FRAME_BITS(bits) SPI_CTAR_FMSZ((bits) - 1)
101 #define SPI_FRAME_BITS_MASK SPI_CTAR_FMSZ(0xf)
102 #define SPI_FRAME_BITS_16 SPI_CTAR_FMSZ(0xf)
103 #define SPI_FRAME_BITS_8 SPI_CTAR_FMSZ(0x7)
105 #define SPI_CS_INIT 0x01
106 #define SPI_CS_ASSERT 0x02
107 #define SPI_CS_DROP 0x04
109 #define SPI_TCR_TCNT_MAX 0x10000
117 enum dspi_trans_mode {
122 struct fsl_dspi_devtype_data {
123 enum dspi_trans_mode trans_mode;
126 static const struct fsl_dspi_devtype_data vf610_data = {
127 .trans_mode = DSPI_EOQ_MODE,
130 static const struct fsl_dspi_devtype_data ls1021a_v1_data = {
131 .trans_mode = DSPI_TCFQ_MODE,
134 static const struct fsl_dspi_devtype_data ls2085a_data = {
135 .trans_mode = DSPI_TCFQ_MODE,
139 struct spi_master *master;
140 struct platform_device *pdev;
142 struct regmap *regmap;
146 struct spi_transfer *cur_transfer;
147 struct spi_message *cur_msg;
148 struct chip_data *cur_chip;
158 struct fsl_dspi_devtype_data *devtype_data;
160 wait_queue_head_t waitq;
166 static inline int is_double_byte_mode(struct fsl_dspi *dspi)
170 regmap_read(dspi->regmap, SPI_CTAR(0), &val);
172 return ((val & SPI_FRAME_BITS_MASK) == SPI_FRAME_BITS(8)) ? 0 : 1;
175 static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
176 unsigned long clkrate)
178 /* Valid baud rate pre-scaler values */
179 int pbr_tbl[4] = {2, 3, 5, 7};
180 int brs[16] = { 2, 4, 6, 8,
182 256, 512, 1024, 2048,
183 4096, 8192, 16384, 32768 };
184 int scale_needed, scale, minscale = INT_MAX;
187 scale_needed = clkrate / speed_hz;
188 if (clkrate % speed_hz)
191 for (i = 0; i < ARRAY_SIZE(brs); i++)
192 for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) {
193 scale = brs[i] * pbr_tbl[j];
194 if (scale >= scale_needed) {
195 if (scale < minscale) {
204 if (minscale == INT_MAX) {
205 pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n",
207 *pbr = ARRAY_SIZE(pbr_tbl) - 1;
208 *br = ARRAY_SIZE(brs) - 1;
212 static void ns_delay_scale(char *psc, char *sc, int delay_ns,
213 unsigned long clkrate)
215 int pscale_tbl[4] = {1, 3, 5, 7};
216 int scale_needed, scale, minscale = INT_MAX;
220 scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC,
225 for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++)
226 for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) {
227 scale = pscale_tbl[i] * (2 << j);
228 if (scale >= scale_needed) {
229 if (scale < minscale) {
238 if (minscale == INT_MAX) {
239 pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value",
241 *psc = ARRAY_SIZE(pscale_tbl) - 1;
242 *sc = SPI_CTAR_SCALE_BITS;
246 static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word)
250 if (!(dspi->dataflags & TRAN_STATE_TX_VOID))
251 d16 = tx_word ? *(u16 *)dspi->tx : *(u8 *)dspi->tx;
253 d16 = dspi->void_write_data;
255 dspi->tx += tx_word + 1;
256 dspi->len -= tx_word + 1;
258 return SPI_PUSHR_TXDATA(d16) |
259 SPI_PUSHR_PCS(dspi->cs) |
264 static void dspi_data_from_popr(struct fsl_dspi *dspi, int rx_word)
269 regmap_read(dspi->regmap, SPI_POPR, &val);
270 d = SPI_POPR_RXDATA(val);
272 if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
273 rx_word ? (*(u16 *)dspi->rx = d) : (*(u8 *)dspi->rx = d);
275 dspi->rx += rx_word + 1;
278 static int dspi_eoq_write(struct fsl_dspi *dspi)
284 tx_word = is_double_byte_mode(dspi);
286 while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) {
287 /* If we are in word mode, only have a single byte to transfer
288 * switch to byte mode temporarily. Will switch back at the
289 * end of the transfer.
291 if (tx_word && (dspi->len == 1)) {
292 dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
293 regmap_update_bits(dspi->regmap, SPI_CTAR(0),
294 SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
298 dspi_pushr = dspi_data_to_pushr(dspi, tx_word);
300 if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) {
301 /* last transfer in the transfer */
302 dspi_pushr |= SPI_PUSHR_EOQ;
303 if ((dspi->cs_change) && (!dspi->len))
304 dspi_pushr &= ~SPI_PUSHR_CONT;
305 } else if (tx_word && (dspi->len == 1))
306 dspi_pushr |= SPI_PUSHR_EOQ;
308 regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
313 return tx_count * (tx_word + 1);
316 static int dspi_eoq_read(struct fsl_dspi *dspi)
319 int rx_word = is_double_byte_mode(dspi);
321 while ((dspi->rx < dspi->rx_end)
322 && (rx_count < DSPI_FIFO_SIZE)) {
323 if (rx_word && (dspi->rx_end - dspi->rx) == 1)
326 dspi_data_from_popr(dspi, rx_word);
333 static int dspi_tcfq_write(struct fsl_dspi *dspi)
338 tx_word = is_double_byte_mode(dspi);
340 if (tx_word && (dspi->len == 1)) {
341 dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
342 regmap_update_bits(dspi->regmap, SPI_CTAR(0),
343 SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
347 dspi_pushr = dspi_data_to_pushr(dspi, tx_word);
349 if ((dspi->cs_change) && (!dspi->len))
350 dspi_pushr &= ~SPI_PUSHR_CONT;
352 regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
357 static void dspi_tcfq_read(struct fsl_dspi *dspi)
359 int rx_word = is_double_byte_mode(dspi);
361 if (rx_word && (dspi->rx_end - dspi->rx) == 1)
364 dspi_data_from_popr(dspi, rx_word);
367 static int dspi_transfer_one_message(struct spi_master *master,
368 struct spi_message *message)
370 struct fsl_dspi *dspi = spi_master_get_devdata(master);
371 struct spi_device *spi = message->spi;
372 struct spi_transfer *transfer;
374 enum dspi_trans_mode trans_mode;
377 regmap_read(dspi->regmap, SPI_TCR, &spi_tcr);
378 dspi->spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr);
380 message->actual_length = 0;
382 list_for_each_entry(transfer, &message->transfers, transfer_list) {
383 dspi->cur_transfer = transfer;
384 dspi->cur_msg = message;
385 dspi->cur_chip = spi_get_ctldata(spi);
386 dspi->cs = spi->chip_select;
388 if (dspi->cur_transfer->transfer_list.next
389 == &dspi->cur_msg->transfers)
391 dspi->void_write_data = dspi->cur_chip->void_write_data;
394 dspi->tx = (void *)transfer->tx_buf;
395 dspi->tx_end = dspi->tx + transfer->len;
396 dspi->rx = transfer->rx_buf;
397 dspi->rx_end = dspi->rx + transfer->len;
398 dspi->len = transfer->len;
401 dspi->dataflags |= TRAN_STATE_RX_VOID;
404 dspi->dataflags |= TRAN_STATE_TX_VOID;
406 regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val);
407 regmap_update_bits(dspi->regmap, SPI_MCR,
408 SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
409 SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);
410 regmap_write(dspi->regmap, SPI_CTAR(0),
411 dspi->cur_chip->ctar_val);
413 trans_mode = dspi->devtype_data->trans_mode;
414 switch (trans_mode) {
416 regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
417 dspi_eoq_write(dspi);
420 regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE);
421 dspi_tcfq_write(dspi);
424 dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
430 if (wait_event_interruptible(dspi->waitq, dspi->waitflags))
431 dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n");
434 if (transfer->delay_usecs)
435 udelay(transfer->delay_usecs);
439 message->status = status;
440 spi_finalize_current_message(master);
445 static int dspi_setup(struct spi_device *spi)
447 struct chip_data *chip;
448 struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
449 u32 cs_sck_delay = 0, sck_cs_delay = 0;
450 unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0;
451 unsigned char pasc = 0, asc = 0, fmsz = 0;
452 unsigned long clkrate;
454 if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) {
455 fmsz = spi->bits_per_word - 1;
457 pr_err("Invalid wordsize\n");
461 /* Only alloc on first setup */
462 chip = spi_get_ctldata(spi);
464 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
469 of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay",
472 of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay",
475 chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS |
476 SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF;
478 chip->void_write_data = 0;
480 clkrate = clk_get_rate(dspi->clk);
481 hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate);
483 /* Set PCS to SCK delay scale values */
484 ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate);
486 /* Set After SCK delay scale values */
487 ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate);
489 chip->ctar_val = SPI_CTAR_FMSZ(fmsz)
490 | SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0)
491 | SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0)
492 | SPI_CTAR_LSBFE(spi->mode & SPI_LSB_FIRST ? 1 : 0)
493 | SPI_CTAR_PCSSCK(pcssck)
494 | SPI_CTAR_CSSCK(cssck)
495 | SPI_CTAR_PASC(pasc)
500 spi_set_ctldata(spi, chip);
505 static void dspi_cleanup(struct spi_device *spi)
507 struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
509 dev_dbg(&spi->dev, "spi_device %u.%u cleanup\n",
510 spi->master->bus_num, spi->chip_select);
515 static irqreturn_t dspi_interrupt(int irq, void *dev_id)
517 struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
518 struct spi_message *msg = dspi->cur_msg;
519 enum dspi_trans_mode trans_mode;
521 u32 spi_tcnt, tcnt_diff;
524 regmap_read(dspi->regmap, SPI_SR, &spi_sr);
525 regmap_write(dspi->regmap, SPI_SR, spi_sr);
528 if (spi_sr & (SPI_SR_EOQF | SPI_SR_TCFQF)) {
529 tx_word = is_double_byte_mode(dspi);
531 regmap_read(dspi->regmap, SPI_TCR, &spi_tcr);
532 spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr);
534 * The width of SPI Transfer Counter in SPI_TCR is 16bits,
535 * so the max couner is 65535. When the counter reach 65535,
536 * it will wrap around, counter reset to zero.
537 * spi_tcnt my be less than dspi->spi_tcnt, it means the
538 * counter already wrapped around.
539 * SPI Transfer Counter is a counter of transmitted frames.
540 * The size of frame maybe two bytes.
542 tcnt_diff = ((spi_tcnt + SPI_TCR_TCNT_MAX) - dspi->spi_tcnt)
544 tcnt_diff *= (tx_word + 1);
545 if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM)
548 msg->actual_length += tcnt_diff;
550 dspi->spi_tcnt = spi_tcnt;
552 trans_mode = dspi->devtype_data->trans_mode;
553 switch (trans_mode) {
558 dspi_tcfq_read(dspi);
561 dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
567 if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM) {
568 regmap_update_bits(dspi->regmap,
572 dspi->dataflags &= ~TRAN_STATE_WORD_ODD_NUM;
576 wake_up_interruptible(&dspi->waitq);
578 switch (trans_mode) {
580 dspi_eoq_write(dspi);
583 dspi_tcfq_write(dspi);
586 dev_err(&dspi->pdev->dev,
587 "unsupported trans_mode %u\n",
596 static const struct of_device_id fsl_dspi_dt_ids[] = {
597 { .compatible = "fsl,vf610-dspi", .data = (void *)&vf610_data, },
598 { .compatible = "fsl,ls1021a-v1.0-dspi",
599 .data = (void *)&ls1021a_v1_data, },
600 { .compatible = "fsl,ls2085a-dspi", .data = (void *)&ls2085a_data, },
603 MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);
605 #ifdef CONFIG_PM_SLEEP
606 static int dspi_suspend(struct device *dev)
608 struct spi_master *master = dev_get_drvdata(dev);
609 struct fsl_dspi *dspi = spi_master_get_devdata(master);
611 spi_master_suspend(master);
612 clk_disable_unprepare(dspi->clk);
614 pinctrl_pm_select_sleep_state(dev);
619 static int dspi_resume(struct device *dev)
621 struct spi_master *master = dev_get_drvdata(dev);
622 struct fsl_dspi *dspi = spi_master_get_devdata(master);
624 pinctrl_pm_select_default_state(dev);
626 clk_prepare_enable(dspi->clk);
627 spi_master_resume(master);
631 #endif /* CONFIG_PM_SLEEP */
633 static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume);
635 static const struct regmap_config dspi_regmap_config = {
639 .max_register = 0x88,
642 static int dspi_probe(struct platform_device *pdev)
644 struct device_node *np = pdev->dev.of_node;
645 struct spi_master *master;
646 struct fsl_dspi *dspi;
647 struct resource *res;
649 int ret = 0, cs_num, bus_num;
650 const struct of_device_id *of_id =
651 of_match_device(fsl_dspi_dt_ids, &pdev->dev);
653 master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
657 dspi = spi_master_get_devdata(master);
659 dspi->master = master;
661 master->transfer = NULL;
662 master->setup = dspi_setup;
663 master->transfer_one_message = dspi_transfer_one_message;
664 master->dev.of_node = pdev->dev.of_node;
666 master->cleanup = dspi_cleanup;
667 master->mode_bits = SPI_CPOL | SPI_CPHA;
668 master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) |
671 ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
673 dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
676 master->num_chipselect = cs_num;
678 ret = of_property_read_u32(np, "bus-num", &bus_num);
680 dev_err(&pdev->dev, "can't get bus-num\n");
683 master->bus_num = bus_num;
685 dspi->devtype_data = (struct fsl_dspi_devtype_data *)of_id->data;
686 if (!dspi->devtype_data) {
687 dev_err(&pdev->dev, "can't get devtype_data\n");
692 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
693 base = devm_ioremap_resource(&pdev->dev, res);
699 dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
700 &dspi_regmap_config);
701 if (IS_ERR(dspi->regmap)) {
702 dev_err(&pdev->dev, "failed to init regmap: %ld\n",
703 PTR_ERR(dspi->regmap));
704 return PTR_ERR(dspi->regmap);
707 dspi->irq = platform_get_irq(pdev, 0);
709 dev_err(&pdev->dev, "can't get platform irq\n");
714 ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0,
717 dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
721 dspi->clk = devm_clk_get(&pdev->dev, "dspi");
722 if (IS_ERR(dspi->clk)) {
723 ret = PTR_ERR(dspi->clk);
724 dev_err(&pdev->dev, "unable to get clock\n");
727 clk_prepare_enable(dspi->clk);
729 init_waitqueue_head(&dspi->waitq);
730 platform_set_drvdata(pdev, master);
732 ret = spi_register_master(master);
734 dev_err(&pdev->dev, "Problem registering DSPI master\n");
741 clk_disable_unprepare(dspi->clk);
743 spi_master_put(master);
748 static int dspi_remove(struct platform_device *pdev)
750 struct spi_master *master = platform_get_drvdata(pdev);
751 struct fsl_dspi *dspi = spi_master_get_devdata(master);
753 /* Disconnect from the SPI framework */
754 clk_disable_unprepare(dspi->clk);
755 spi_unregister_master(dspi->master);
760 static struct platform_driver fsl_dspi_driver = {
761 .driver.name = DRIVER_NAME,
762 .driver.of_match_table = fsl_dspi_dt_ids,
763 .driver.owner = THIS_MODULE,
764 .driver.pm = &dspi_pm,
766 .remove = dspi_remove,
768 module_platform_driver(fsl_dspi_driver);
770 MODULE_DESCRIPTION("Freescale DSPI Controller Driver");
771 MODULE_LICENSE("GPL");
772 MODULE_ALIAS("platform:" DRIVER_NAME);