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 = DIV_ROUND_UP(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, u32 cs_high)
178 * CPOL CPHA TSCKIZ RSCKIZ TEDG REDG
184 sh_msiof_write(p, FCTR, 0);
187 tmp |= !cs_high << 25;
188 tmp |= lsb_first << 24;
189 sh_msiof_write(p, TMDR1, 0xe0000005 | tmp);
190 sh_msiof_write(p, RMDR1, 0x20000005 | tmp);
193 tmp |= cpol << 30; /* TSCKIZ */
194 tmp |= cpol << 28; /* RSCKIZ */
198 tmp |= edge << 27; /* TEDG */
199 tmp |= edge << 26; /* REDG */
200 tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
201 sh_msiof_write(p, CTR, tmp);
204 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
205 const void *tx_buf, void *rx_buf,
208 u32 dr2 = ((bits - 1) << 24) | ((words - 1) << 16);
211 sh_msiof_write(p, TMDR2, dr2);
213 sh_msiof_write(p, TMDR2, dr2 | 1);
216 sh_msiof_write(p, RMDR2, dr2);
218 sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
221 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
223 sh_msiof_write(p, STR, sh_msiof_read(p, STR));
226 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
227 const void *tx_buf, int words, int fs)
229 const u8 *buf_8 = tx_buf;
232 for (k = 0; k < words; k++)
233 sh_msiof_write(p, TFDR, buf_8[k] << fs);
236 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
237 const void *tx_buf, int words, int fs)
239 const u16 *buf_16 = tx_buf;
242 for (k = 0; k < words; k++)
243 sh_msiof_write(p, TFDR, buf_16[k] << fs);
246 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
247 const void *tx_buf, int words, int fs)
249 const u16 *buf_16 = tx_buf;
252 for (k = 0; k < words; k++)
253 sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
256 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
257 const void *tx_buf, int words, int fs)
259 const u32 *buf_32 = tx_buf;
262 for (k = 0; k < words; k++)
263 sh_msiof_write(p, TFDR, buf_32[k] << fs);
266 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
267 const void *tx_buf, int words, int fs)
269 const u32 *buf_32 = tx_buf;
272 for (k = 0; k < words; k++)
273 sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
276 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
277 const void *tx_buf, int words, int fs)
279 const u32 *buf_32 = tx_buf;
282 for (k = 0; k < words; k++)
283 sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
286 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
287 const void *tx_buf, int words, int fs)
289 const u32 *buf_32 = tx_buf;
292 for (k = 0; k < words; k++)
293 sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
296 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
297 void *rx_buf, int words, int fs)
302 for (k = 0; k < words; k++)
303 buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
306 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
307 void *rx_buf, int words, int fs)
309 u16 *buf_16 = rx_buf;
312 for (k = 0; k < words; k++)
313 buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
316 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
317 void *rx_buf, int words, int fs)
319 u16 *buf_16 = rx_buf;
322 for (k = 0; k < words; k++)
323 put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
326 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
327 void *rx_buf, int words, int fs)
329 u32 *buf_32 = rx_buf;
332 for (k = 0; k < words; k++)
333 buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
336 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
337 void *rx_buf, int words, int fs)
339 u32 *buf_32 = rx_buf;
342 for (k = 0; k < words; k++)
343 put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
346 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
347 void *rx_buf, int words, int fs)
349 u32 *buf_32 = rx_buf;
352 for (k = 0; k < words; k++)
353 buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
356 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
357 void *rx_buf, int words, int fs)
359 u32 *buf_32 = rx_buf;
362 for (k = 0; k < words; k++)
363 put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
366 static int sh_msiof_spi_bits(struct spi_device *spi, struct spi_transfer *t)
370 bits = t ? t->bits_per_word : 0;
372 bits = spi->bits_per_word;
376 static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
377 struct spi_transfer *t)
381 hz = t ? t->speed_hz : 0;
383 hz = spi->max_speed_hz;
387 static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
388 struct spi_transfer *t)
392 /* noting to check hz values against since parent clock is disabled */
394 bits = sh_msiof_spi_bits(spi, t);
400 return spi_bitbang_setup_transfer(spi, t);
403 static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
405 struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
408 /* chip select is active low unless SPI_CS_HIGH is set */
409 if (spi->mode & SPI_CS_HIGH)
410 value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
412 value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;
414 if (is_on == BITBANG_CS_ACTIVE) {
415 if (!test_and_set_bit(0, &p->flags)) {
416 pm_runtime_get_sync(&p->pdev->dev);
420 /* Configure pins before asserting CS */
421 sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
422 !!(spi->mode & SPI_CPHA),
423 !!(spi->mode & SPI_3WIRE),
424 !!(spi->mode & SPI_LSB_FIRST),
425 !!(spi->mode & SPI_CS_HIGH));
428 /* use spi->controller data for CS (same strategy as spi_gpio) */
429 gpio_set_value((uintptr_t)spi->controller_data, value);
431 if (is_on == BITBANG_CS_INACTIVE) {
432 if (test_and_clear_bit(0, &p->flags)) {
434 pm_runtime_put(&p->pdev->dev);
439 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
440 void (*tx_fifo)(struct sh_msiof_spi_priv *,
441 const void *, int, int),
442 void (*rx_fifo)(struct sh_msiof_spi_priv *,
444 const void *tx_buf, void *rx_buf,
450 /* limit maximum word transfer to rx/tx fifo size */
452 words = min_t(int, words, p->tx_fifo_size);
454 words = min_t(int, words, p->rx_fifo_size);
456 /* the fifo contents need shifting */
457 fifo_shift = 32 - bits;
459 /* setup msiof transfer mode registers */
460 sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
464 tx_fifo(p, tx_buf, words, fifo_shift);
466 /* setup clock and rx/tx signals */
467 ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
469 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
470 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
472 /* start by setting frame bit */
473 reinit_completion(&p->done);
474 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
476 dev_err(&p->pdev->dev, "failed to start hardware\n");
480 /* wait for tx fifo to be emptied / rx fifo to be filled */
481 wait_for_completion(&p->done);
485 rx_fifo(p, rx_buf, words, fifo_shift);
487 /* clear status bits */
488 sh_msiof_reset_str(p);
490 /* shut down frame, tx/tx and clock signals */
491 ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
492 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
494 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
495 ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
497 dev_err(&p->pdev->dev, "failed to shut down hardware\n");
504 sh_msiof_write(p, IER, 0);
508 static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
510 struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
511 void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
512 void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
520 bits = sh_msiof_spi_bits(spi, t);
522 if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
529 /* setup bytes per word and fifo read/write functions */
532 tx_fifo = sh_msiof_spi_write_fifo_8;
533 rx_fifo = sh_msiof_spi_read_fifo_8;
534 } else if (bits <= 16) {
536 if ((unsigned long)t->tx_buf & 0x01)
537 tx_fifo = sh_msiof_spi_write_fifo_16u;
539 tx_fifo = sh_msiof_spi_write_fifo_16;
541 if ((unsigned long)t->rx_buf & 0x01)
542 rx_fifo = sh_msiof_spi_read_fifo_16u;
544 rx_fifo = sh_msiof_spi_read_fifo_16;
547 if ((unsigned long)t->tx_buf & 0x03)
548 tx_fifo = sh_msiof_spi_write_fifo_s32u;
550 tx_fifo = sh_msiof_spi_write_fifo_s32;
552 if ((unsigned long)t->rx_buf & 0x03)
553 rx_fifo = sh_msiof_spi_read_fifo_s32u;
555 rx_fifo = sh_msiof_spi_read_fifo_s32;
558 if ((unsigned long)t->tx_buf & 0x03)
559 tx_fifo = sh_msiof_spi_write_fifo_32u;
561 tx_fifo = sh_msiof_spi_write_fifo_32;
563 if ((unsigned long)t->rx_buf & 0x03)
564 rx_fifo = sh_msiof_spi_read_fifo_32u;
566 rx_fifo = sh_msiof_spi_read_fifo_32;
569 /* setup clocks (clock already enabled in chipselect()) */
570 sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
571 sh_msiof_spi_hz(spi, t));
573 /* transfer in fifo sized chunks */
574 words = t->len / bytes_per_word;
577 while (bytes_done < t->len) {
578 void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
579 const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
580 n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
587 bytes_done += n * bytes_per_word;
594 static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
597 BUG(); /* unused but needed by bitbang code */
602 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
604 struct sh_msiof_spi_info *info;
605 struct device_node *np = dev->of_node;
608 info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
610 dev_err(dev, "failed to allocate setup data\n");
614 /* Parse the MSIOF properties */
615 of_property_read_u32(np, "num-cs", &num_cs);
616 of_property_read_u32(np, "renesas,tx-fifo-size",
617 &info->tx_fifo_override);
618 of_property_read_u32(np, "renesas,rx-fifo-size",
619 &info->rx_fifo_override);
621 info->num_chipselect = num_cs;
626 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
632 static int sh_msiof_spi_probe(struct platform_device *pdev)
635 struct spi_master *master;
636 struct sh_msiof_spi_priv *p;
640 master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
641 if (master == NULL) {
642 dev_err(&pdev->dev, "failed to allocate spi master\n");
646 p = spi_master_get_devdata(master);
648 platform_set_drvdata(pdev, p);
649 if (pdev->dev.of_node)
650 p->info = sh_msiof_spi_parse_dt(&pdev->dev);
652 p->info = dev_get_platdata(&pdev->dev);
655 dev_err(&pdev->dev, "failed to obtain device info\n");
660 init_completion(&p->done);
662 p->clk = devm_clk_get(&pdev->dev, NULL);
663 if (IS_ERR(p->clk)) {
664 dev_err(&pdev->dev, "cannot get clock\n");
665 ret = PTR_ERR(p->clk);
669 i = platform_get_irq(pdev, 0);
671 dev_err(&pdev->dev, "cannot get platform IRQ\n");
676 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
677 p->mapbase = devm_ioremap_resource(&pdev->dev, r);
678 if (IS_ERR(p->mapbase)) {
679 ret = PTR_ERR(p->mapbase);
683 ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
684 dev_name(&pdev->dev), p);
686 dev_err(&pdev->dev, "unable to request irq\n");
690 ret = clk_prepare(p->clk);
692 dev_err(&pdev->dev, "unable to prepare clock\n");
697 pm_runtime_enable(&pdev->dev);
699 /* The standard version of MSIOF use 64 word FIFOs */
700 p->tx_fifo_size = 64;
701 p->rx_fifo_size = 64;
703 /* Platform data may override FIFO sizes */
704 if (p->info->tx_fifo_override)
705 p->tx_fifo_size = p->info->tx_fifo_override;
706 if (p->info->rx_fifo_override)
707 p->rx_fifo_size = p->info->rx_fifo_override;
709 /* init master and bitbang code */
710 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
711 master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
713 master->bus_num = pdev->id;
714 master->num_chipselect = p->info->num_chipselect;
715 master->setup = spi_bitbang_setup;
716 master->cleanup = spi_bitbang_cleanup;
718 p->bitbang.master = master;
719 p->bitbang.chipselect = sh_msiof_spi_chipselect;
720 p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
721 p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
722 p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
723 p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
724 p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
725 p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
727 ret = spi_bitbang_start(&p->bitbang);
731 pm_runtime_disable(&pdev->dev);
732 clk_unprepare(p->clk);
734 spi_master_put(master);
738 static int sh_msiof_spi_remove(struct platform_device *pdev)
740 struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
743 ret = spi_bitbang_stop(&p->bitbang);
745 pm_runtime_disable(&pdev->dev);
746 clk_unprepare(p->clk);
747 spi_master_put(p->bitbang.master);
753 static const struct of_device_id sh_msiof_match[] = {
754 { .compatible = "renesas,sh-msiof", },
755 { .compatible = "renesas,sh-mobile-msiof", },
758 MODULE_DEVICE_TABLE(of, sh_msiof_match);
761 static struct platform_driver sh_msiof_spi_drv = {
762 .probe = sh_msiof_spi_probe,
763 .remove = sh_msiof_spi_remove,
765 .name = "spi_sh_msiof",
766 .owner = THIS_MODULE,
767 .of_match_table = of_match_ptr(sh_msiof_match),
770 module_platform_driver(sh_msiof_spi_drv);
772 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
773 MODULE_AUTHOR("Magnus Damm");
774 MODULE_LICENSE("GPL v2");
775 MODULE_ALIAS("platform:spi_sh_msiof");