2 * SuperH MSIOF SPI Master Interface
4 * Copyright (c) 2009 Magnus Damm
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
12 #include <linux/bitmap.h>
13 #include <linux/clk.h>
14 #include <linux/completion.h>
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
27 #include <linux/spi/sh_msiof.h>
28 #include <linux/spi/spi.h>
29 #include <linux/spi/spi_bitbang.h>
31 #include <asm/unaligned.h>
33 struct sh_msiof_spi_priv {
34 struct spi_bitbang bitbang; /* must be first for spi_bitbang.c */
35 void __iomem *mapbase;
37 struct platform_device *pdev;
38 struct sh_msiof_spi_info *info;
39 struct completion done;
64 #define CTR_TSCKE (1 << 15)
65 #define CTR_TFSE (1 << 14)
66 #define CTR_TXE (1 << 9)
67 #define CTR_RXE (1 << 8)
69 #define STR_TEOF (1 << 23)
70 #define STR_REOF (1 << 7)
72 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
77 return ioread16(p->mapbase + reg_offs);
79 return ioread32(p->mapbase + reg_offs);
83 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
89 iowrite16(value, p->mapbase + reg_offs);
92 iowrite32(value, p->mapbase + reg_offs);
97 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
100 u32 mask = clr | set;
104 data = sh_msiof_read(p, CTR);
107 sh_msiof_write(p, CTR, data);
109 for (k = 100; k > 0; k--) {
110 if ((sh_msiof_read(p, CTR) & mask) == set)
116 return k > 0 ? 0 : -ETIMEDOUT;
119 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
121 struct sh_msiof_spi_priv *p = data;
123 /* just disable the interrupt and wake up */
124 sh_msiof_write(p, IER, 0);
133 } const sh_msiof_spi_clk_table[] = {
147 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
148 unsigned long parent_rate,
149 unsigned long spi_hz)
151 unsigned long div = 1024;
154 if (!WARN_ON(!spi_hz || !parent_rate))
155 div = parent_rate / spi_hz;
157 /* TODO: make more fine grained */
159 for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) {
160 if (sh_msiof_spi_clk_table[k].div >= div)
164 k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1);
166 sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr);
167 sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
170 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
172 u32 tx_hi_z, u32 lsb_first)
178 * CPOL CPHA TSCKIZ RSCKIZ TEDG REDG
184 sh_msiof_write(p, FCTR, 0);
185 sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24));
186 sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24));
189 tmp |= cpol << 30; /* TSCKIZ */
190 tmp |= cpol << 28; /* RSCKIZ */
194 tmp |= edge << 27; /* TEDG */
195 tmp |= edge << 26; /* REDG */
196 tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
197 sh_msiof_write(p, CTR, tmp);
200 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
201 const void *tx_buf, void *rx_buf,
204 u32 dr2 = ((bits - 1) << 24) | ((words - 1) << 16);
207 sh_msiof_write(p, TMDR2, dr2);
209 sh_msiof_write(p, TMDR2, dr2 | 1);
212 sh_msiof_write(p, RMDR2, dr2);
214 sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
217 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
219 sh_msiof_write(p, STR, sh_msiof_read(p, STR));
222 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
223 const void *tx_buf, int words, int fs)
225 const u8 *buf_8 = tx_buf;
228 for (k = 0; k < words; k++)
229 sh_msiof_write(p, TFDR, buf_8[k] << fs);
232 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
233 const void *tx_buf, int words, int fs)
235 const u16 *buf_16 = tx_buf;
238 for (k = 0; k < words; k++)
239 sh_msiof_write(p, TFDR, buf_16[k] << fs);
242 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
243 const void *tx_buf, int words, int fs)
245 const u16 *buf_16 = tx_buf;
248 for (k = 0; k < words; k++)
249 sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
252 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
253 const void *tx_buf, int words, int fs)
255 const u32 *buf_32 = tx_buf;
258 for (k = 0; k < words; k++)
259 sh_msiof_write(p, TFDR, buf_32[k] << fs);
262 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
263 const void *tx_buf, int words, int fs)
265 const u32 *buf_32 = tx_buf;
268 for (k = 0; k < words; k++)
269 sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
272 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
273 const void *tx_buf, int words, int fs)
275 const u32 *buf_32 = tx_buf;
278 for (k = 0; k < words; k++)
279 sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
282 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
283 const void *tx_buf, int words, int fs)
285 const u32 *buf_32 = tx_buf;
288 for (k = 0; k < words; k++)
289 sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
292 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
293 void *rx_buf, int words, int fs)
298 for (k = 0; k < words; k++)
299 buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
302 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
303 void *rx_buf, int words, int fs)
305 u16 *buf_16 = rx_buf;
308 for (k = 0; k < words; k++)
309 buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
312 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
313 void *rx_buf, int words, int fs)
315 u16 *buf_16 = rx_buf;
318 for (k = 0; k < words; k++)
319 put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
322 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
323 void *rx_buf, int words, int fs)
325 u32 *buf_32 = rx_buf;
328 for (k = 0; k < words; k++)
329 buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
332 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
333 void *rx_buf, int words, int fs)
335 u32 *buf_32 = rx_buf;
338 for (k = 0; k < words; k++)
339 put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
342 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
343 void *rx_buf, int words, int fs)
345 u32 *buf_32 = rx_buf;
348 for (k = 0; k < words; k++)
349 buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
352 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
353 void *rx_buf, int words, int fs)
355 u32 *buf_32 = rx_buf;
358 for (k = 0; k < words; k++)
359 put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
362 static int sh_msiof_spi_bits(struct spi_device *spi, struct spi_transfer *t)
366 bits = t ? t->bits_per_word : 0;
368 bits = spi->bits_per_word;
372 static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
373 struct spi_transfer *t)
377 hz = t ? t->speed_hz : 0;
379 hz = spi->max_speed_hz;
383 static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
384 struct spi_transfer *t)
388 /* noting to check hz values against since parent clock is disabled */
390 bits = sh_msiof_spi_bits(spi, t);
396 return spi_bitbang_setup_transfer(spi, t);
399 static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
401 struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
404 /* chip select is active low unless SPI_CS_HIGH is set */
405 if (spi->mode & SPI_CS_HIGH)
406 value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
408 value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;
410 if (is_on == BITBANG_CS_ACTIVE) {
411 if (!test_and_set_bit(0, &p->flags)) {
412 pm_runtime_get_sync(&p->pdev->dev);
416 /* Configure pins before asserting CS */
417 sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
418 !!(spi->mode & SPI_CPHA),
419 !!(spi->mode & SPI_3WIRE),
420 !!(spi->mode & SPI_LSB_FIRST));
423 /* use spi->controller data for CS (same strategy as spi_gpio) */
424 gpio_set_value((unsigned)spi->controller_data, value);
426 if (is_on == BITBANG_CS_INACTIVE) {
427 if (test_and_clear_bit(0, &p->flags)) {
429 pm_runtime_put(&p->pdev->dev);
434 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
435 void (*tx_fifo)(struct sh_msiof_spi_priv *,
436 const void *, int, int),
437 void (*rx_fifo)(struct sh_msiof_spi_priv *,
439 const void *tx_buf, void *rx_buf,
445 /* limit maximum word transfer to rx/tx fifo size */
447 words = min_t(int, words, p->tx_fifo_size);
449 words = min_t(int, words, p->rx_fifo_size);
451 /* the fifo contents need shifting */
452 fifo_shift = 32 - bits;
454 /* setup msiof transfer mode registers */
455 sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
459 tx_fifo(p, tx_buf, words, fifo_shift);
461 /* setup clock and rx/tx signals */
462 ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
464 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
465 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
467 /* start by setting frame bit */
468 INIT_COMPLETION(p->done);
469 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
471 dev_err(&p->pdev->dev, "failed to start hardware\n");
475 /* wait for tx fifo to be emptied / rx fifo to be filled */
476 wait_for_completion(&p->done);
480 rx_fifo(p, rx_buf, words, fifo_shift);
482 /* clear status bits */
483 sh_msiof_reset_str(p);
485 /* shut down frame, tx/tx and clock signals */
486 ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
487 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
489 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
490 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
492 dev_err(&p->pdev->dev, "failed to shut down hardware\n");
499 sh_msiof_write(p, IER, 0);
503 static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
505 struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
506 void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
507 void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
515 bits = sh_msiof_spi_bits(spi, t);
517 if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
524 /* setup bytes per word and fifo read/write functions */
527 tx_fifo = sh_msiof_spi_write_fifo_8;
528 rx_fifo = sh_msiof_spi_read_fifo_8;
529 } else if (bits <= 16) {
531 if ((unsigned long)t->tx_buf & 0x01)
532 tx_fifo = sh_msiof_spi_write_fifo_16u;
534 tx_fifo = sh_msiof_spi_write_fifo_16;
536 if ((unsigned long)t->rx_buf & 0x01)
537 rx_fifo = sh_msiof_spi_read_fifo_16u;
539 rx_fifo = sh_msiof_spi_read_fifo_16;
542 if ((unsigned long)t->tx_buf & 0x03)
543 tx_fifo = sh_msiof_spi_write_fifo_s32u;
545 tx_fifo = sh_msiof_spi_write_fifo_s32;
547 if ((unsigned long)t->rx_buf & 0x03)
548 rx_fifo = sh_msiof_spi_read_fifo_s32u;
550 rx_fifo = sh_msiof_spi_read_fifo_s32;
553 if ((unsigned long)t->tx_buf & 0x03)
554 tx_fifo = sh_msiof_spi_write_fifo_32u;
556 tx_fifo = sh_msiof_spi_write_fifo_32;
558 if ((unsigned long)t->rx_buf & 0x03)
559 rx_fifo = sh_msiof_spi_read_fifo_32u;
561 rx_fifo = sh_msiof_spi_read_fifo_32;
564 /* setup clocks (clock already enabled in chipselect()) */
565 sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
566 sh_msiof_spi_hz(spi, t));
568 /* transfer in fifo sized chunks */
569 words = t->len / bytes_per_word;
572 while (bytes_done < t->len) {
573 void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
574 const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
575 n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
582 bytes_done += n * bytes_per_word;
589 static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
592 BUG(); /* unused but needed by bitbang code */
597 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
599 struct sh_msiof_spi_info *info;
600 struct device_node *np = dev->of_node;
603 info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
605 dev_err(dev, "failed to allocate setup data\n");
609 /* Parse the MSIOF properties */
610 of_property_read_u32(np, "num-cs", &num_cs);
611 of_property_read_u32(np, "renesas,tx-fifo-size",
612 &info->tx_fifo_override);
613 of_property_read_u32(np, "renesas,rx-fifo-size",
614 &info->rx_fifo_override);
616 info->num_chipselect = num_cs;
621 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
627 static int sh_msiof_spi_probe(struct platform_device *pdev)
630 struct spi_master *master;
631 struct sh_msiof_spi_priv *p;
635 master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
636 if (master == NULL) {
637 dev_err(&pdev->dev, "failed to allocate spi master\n");
642 p = spi_master_get_devdata(master);
644 platform_set_drvdata(pdev, p);
645 if (pdev->dev.of_node)
646 p->info = sh_msiof_spi_parse_dt(&pdev->dev);
648 p->info = pdev->dev.platform_data;
651 dev_err(&pdev->dev, "failed to obtain device info\n");
656 init_completion(&p->done);
658 p->clk = clk_get(&pdev->dev, NULL);
659 if (IS_ERR(p->clk)) {
660 dev_err(&pdev->dev, "cannot get clock\n");
661 ret = PTR_ERR(p->clk);
665 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
666 i = platform_get_irq(pdev, 0);
668 dev_err(&pdev->dev, "cannot get platform resources\n");
672 p->mapbase = ioremap_nocache(r->start, resource_size(r));
674 dev_err(&pdev->dev, "unable to ioremap\n");
679 ret = request_irq(i, sh_msiof_spi_irq, 0,
680 dev_name(&pdev->dev), p);
682 dev_err(&pdev->dev, "unable to request irq\n");
687 pm_runtime_enable(&pdev->dev);
689 /* The standard version of MSIOF use 64 word FIFOs */
690 p->tx_fifo_size = 64;
691 p->rx_fifo_size = 64;
693 /* Platform data may override FIFO sizes */
694 if (p->info->tx_fifo_override)
695 p->tx_fifo_size = p->info->tx_fifo_override;
696 if (p->info->rx_fifo_override)
697 p->rx_fifo_size = p->info->rx_fifo_override;
699 /* init master and bitbang code */
700 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
701 master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
703 master->bus_num = pdev->id;
704 master->num_chipselect = p->info->num_chipselect;
705 master->setup = spi_bitbang_setup;
706 master->cleanup = spi_bitbang_cleanup;
708 p->bitbang.master = master;
709 p->bitbang.chipselect = sh_msiof_spi_chipselect;
710 p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
711 p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
712 p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
713 p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
714 p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
715 p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
717 ret = spi_bitbang_start(&p->bitbang);
721 pm_runtime_disable(&pdev->dev);
727 spi_master_put(master);
732 static int sh_msiof_spi_remove(struct platform_device *pdev)
734 struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
737 ret = spi_bitbang_stop(&p->bitbang);
739 pm_runtime_disable(&pdev->dev);
740 free_irq(platform_get_irq(pdev, 0), p);
743 spi_master_put(p->bitbang.master);
748 static int sh_msiof_spi_runtime_nop(struct device *dev)
750 /* Runtime PM callback shared between ->runtime_suspend()
751 * and ->runtime_resume(). Simply returns success.
753 * This driver re-initializes all registers after
754 * pm_runtime_get_sync() anyway so there is no need
755 * to save and restore registers here.
761 static const struct of_device_id sh_msiof_match[] = {
762 { .compatible = "renesas,sh-msiof", },
763 { .compatible = "renesas,sh-mobile-msiof", },
766 MODULE_DEVICE_TABLE(of, sh_msiof_match);
768 #define sh_msiof_match NULL
771 static struct dev_pm_ops sh_msiof_spi_dev_pm_ops = {
772 .runtime_suspend = sh_msiof_spi_runtime_nop,
773 .runtime_resume = sh_msiof_spi_runtime_nop,
776 static struct platform_driver sh_msiof_spi_drv = {
777 .probe = sh_msiof_spi_probe,
778 .remove = sh_msiof_spi_remove,
780 .name = "spi_sh_msiof",
781 .owner = THIS_MODULE,
782 .pm = &sh_msiof_spi_dev_pm_ops,
783 .of_match_table = sh_msiof_match,
786 module_platform_driver(sh_msiof_spi_drv);
788 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
789 MODULE_AUTHOR("Magnus Damm");
790 MODULE_LICENSE("GPL v2");
791 MODULE_ALIAS("platform:spi_sh_msiof");