1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Broadcom BCM63xx SPI controller support
5 * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
6 * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
9 #include <linux/kernel.h>
10 #include <linux/clk.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/delay.h>
15 #include <linux/interrupt.h>
16 #include <linux/spi/spi.h>
17 #include <linux/completion.h>
18 #include <linux/err.h>
19 #include <linux/pm_runtime.h>
21 #include <linux/reset.h>
23 /* BCM 6338/6348 SPI core */
24 #define SPI_6348_RSET_SIZE 64
25 #define SPI_6348_CMD 0x00 /* 16-bits register */
26 #define SPI_6348_INT_STATUS 0x02
27 #define SPI_6348_INT_MASK_ST 0x03
28 #define SPI_6348_INT_MASK 0x04
29 #define SPI_6348_ST 0x05
30 #define SPI_6348_CLK_CFG 0x06
31 #define SPI_6348_FILL_BYTE 0x07
32 #define SPI_6348_MSG_TAIL 0x09
33 #define SPI_6348_RX_TAIL 0x0b
34 #define SPI_6348_MSG_CTL 0x40 /* 8-bits register */
35 #define SPI_6348_MSG_CTL_WIDTH 8
36 #define SPI_6348_MSG_DATA 0x41
37 #define SPI_6348_MSG_DATA_SIZE 0x3f
38 #define SPI_6348_RX_DATA 0x80
39 #define SPI_6348_RX_DATA_SIZE 0x3f
41 /* BCM 3368/6358/6262/6368 SPI core */
42 #define SPI_6358_RSET_SIZE 1804
43 #define SPI_6358_MSG_CTL 0x00 /* 16-bits register */
44 #define SPI_6358_MSG_CTL_WIDTH 16
45 #define SPI_6358_MSG_DATA 0x02
46 #define SPI_6358_MSG_DATA_SIZE 0x21e
47 #define SPI_6358_RX_DATA 0x400
48 #define SPI_6358_RX_DATA_SIZE 0x220
49 #define SPI_6358_CMD 0x700 /* 16-bits register */
50 #define SPI_6358_INT_STATUS 0x702
51 #define SPI_6358_INT_MASK_ST 0x703
52 #define SPI_6358_INT_MASK 0x704
53 #define SPI_6358_ST 0x705
54 #define SPI_6358_CLK_CFG 0x706
55 #define SPI_6358_FILL_BYTE 0x707
56 #define SPI_6358_MSG_TAIL 0x709
57 #define SPI_6358_RX_TAIL 0x70B
59 /* Shared SPI definitions */
61 /* Message configuration */
62 #define SPI_FD_RW 0x00
65 #define SPI_BYTE_CNT_SHIFT 0
66 #define SPI_6348_MSG_TYPE_SHIFT 6
67 #define SPI_6358_MSG_TYPE_SHIFT 14
70 #define SPI_CMD_NOOP 0x00
71 #define SPI_CMD_SOFT_RESET 0x01
72 #define SPI_CMD_HARD_RESET 0x02
73 #define SPI_CMD_START_IMMEDIATE 0x03
74 #define SPI_CMD_COMMAND_SHIFT 0
75 #define SPI_CMD_COMMAND_MASK 0x000f
76 #define SPI_CMD_DEVICE_ID_SHIFT 4
77 #define SPI_CMD_PREPEND_BYTE_CNT_SHIFT 8
78 #define SPI_CMD_ONE_BYTE_SHIFT 11
79 #define SPI_CMD_ONE_WIRE_SHIFT 12
80 #define SPI_DEV_ID_0 0
81 #define SPI_DEV_ID_1 1
82 #define SPI_DEV_ID_2 2
83 #define SPI_DEV_ID_3 3
86 #define SPI_INTR_CMD_DONE 0x01
87 #define SPI_INTR_RX_OVERFLOW 0x02
88 #define SPI_INTR_TX_UNDERFLOW 0x04
89 #define SPI_INTR_TX_OVERFLOW 0x08
90 #define SPI_INTR_RX_UNDERFLOW 0x10
91 #define SPI_INTR_CLEAR_ALL 0x1f
94 #define SPI_RX_EMPTY 0x02
95 #define SPI_CMD_BUSY 0x04
96 #define SPI_SERIAL_BUSY 0x08
98 /* Clock configuration */
99 #define SPI_CLK_20MHZ 0x00
100 #define SPI_CLK_0_391MHZ 0x01
101 #define SPI_CLK_0_781MHZ 0x02 /* default */
102 #define SPI_CLK_1_563MHZ 0x03
103 #define SPI_CLK_3_125MHZ 0x04
104 #define SPI_CLK_6_250MHZ 0x05
105 #define SPI_CLK_12_50MHZ 0x06
106 #define SPI_CLK_MASK 0x07
107 #define SPI_SSOFFTIME_MASK 0x38
108 #define SPI_SSOFFTIME_SHIFT 3
109 #define SPI_BYTE_SWAP 0x80
111 enum bcm63xx_regs_spi {
129 #define BCM63XX_SPI_MAX_PREPEND 15
131 #define BCM63XX_SPI_MAX_CS 8
132 #define BCM63XX_SPI_BUS_NUM 0
135 struct completion done;
141 const unsigned long *reg_offsets;
142 unsigned int fifo_size;
143 unsigned int msg_type_shift;
144 unsigned int msg_ctl_width;
148 const u8 __iomem *rx_io;
151 struct platform_device *pdev;
154 static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
157 return readb(bs->regs + bs->reg_offsets[offset]);
160 static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
163 #ifdef CONFIG_CPU_BIG_ENDIAN
164 return ioread16be(bs->regs + bs->reg_offsets[offset]);
166 return readw(bs->regs + bs->reg_offsets[offset]);
170 static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
171 u8 value, unsigned int offset)
173 writeb(value, bs->regs + bs->reg_offsets[offset]);
176 static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
177 u16 value, unsigned int offset)
179 #ifdef CONFIG_CPU_BIG_ENDIAN
180 iowrite16be(value, bs->regs + bs->reg_offsets[offset]);
182 writew(value, bs->regs + bs->reg_offsets[offset]);
186 static const unsigned int bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
187 { 20000000, SPI_CLK_20MHZ },
188 { 12500000, SPI_CLK_12_50MHZ },
189 { 6250000, SPI_CLK_6_250MHZ },
190 { 3125000, SPI_CLK_3_125MHZ },
191 { 1563000, SPI_CLK_1_563MHZ },
192 { 781000, SPI_CLK_0_781MHZ },
193 { 391000, SPI_CLK_0_391MHZ }
196 static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
197 struct spi_transfer *t)
199 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
203 /* Default to lowest clock configuration */
204 clk_cfg = SPI_CLK_0_391MHZ;
206 /* Find the closest clock configuration */
207 for (i = 0; i < SPI_CLK_MASK; i++) {
208 if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
209 clk_cfg = bcm63xx_spi_freq_table[i][1];
214 /* clear existing clock configuration bits of the register */
215 reg = bcm_spi_readb(bs, SPI_CLK_CFG);
216 reg &= ~SPI_CLK_MASK;
219 bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
220 dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
221 clk_cfg, t->speed_hz);
224 /* the spi->mode bits understood by this driver: */
225 #define MODEBITS (SPI_CPOL | SPI_CPHA)
227 static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
228 unsigned int num_transfers)
230 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
233 unsigned int i, timeout = 0, prepend_len = 0, len = 0;
234 struct spi_transfer *t = first;
238 /* Disable the CMD_DONE interrupt */
239 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
241 dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
242 t->tx_buf, t->rx_buf, t->len);
244 if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
245 prepend_len = t->len;
247 /* prepare the buffer */
248 for (i = 0; i < num_transfers; i++) {
251 memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
253 /* don't prepend more than one tx */
260 /* prepend is half-duplex write only */
267 t = list_entry(t->transfer_list.next, struct spi_transfer,
271 reinit_completion(&bs->done);
273 /* Fill in the Message control register */
274 msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
276 if (do_rx && do_tx && prepend_len == 0)
277 msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
279 msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
281 msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
283 switch (bs->msg_ctl_width) {
285 bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
288 bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
292 /* Issue the transfer */
293 cmd = SPI_CMD_START_IMMEDIATE;
294 cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
295 cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
296 bcm_spi_writew(bs, cmd, SPI_CMD);
298 /* Enable the CMD_DONE interrupt */
299 bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
301 timeout = wait_for_completion_timeout(&bs->done, HZ);
310 /* Read out all the data */
311 for (i = 0; i < num_transfers; i++) {
313 memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
315 if (t != first || prepend_len == 0)
318 t = list_entry(t->transfer_list.next, struct spi_transfer,
325 static int bcm63xx_spi_transfer_one(struct spi_master *master,
326 struct spi_message *m)
328 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
329 struct spi_transfer *t, *first = NULL;
330 struct spi_device *spi = m->spi;
332 unsigned int n_transfers = 0, total_len = 0;
333 bool can_use_prepend = false;
336 * This SPI controller does not support keeping CS active after a
338 * Work around this by merging as many transfers we can into one big
339 * full-duplex transfers.
341 list_for_each_entry(t, &m->transfers, transfer_list) {
348 if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
349 first->len <= BCM63XX_SPI_MAX_PREPEND)
350 can_use_prepend = true;
351 else if (can_use_prepend && t->tx_buf)
352 can_use_prepend = false;
354 /* we can only transfer one fifo worth of data */
355 if ((can_use_prepend &&
356 total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
357 (!can_use_prepend && total_len > bs->fifo_size)) {
358 dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
359 total_len, bs->fifo_size);
364 /* all combined transfers have to have the same speed */
365 if (t->speed_hz != first->speed_hz) {
366 dev_err(&spi->dev, "unable to change speed between transfers\n");
371 /* CS will be deasserted directly after transfer */
372 if (t->delay.value) {
373 dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
379 list_is_last(&t->transfer_list, &m->transfers)) {
380 /* configure adapter for a new transfer */
381 bcm63xx_spi_setup_transfer(spi, first);
384 status = bcm63xx_txrx_bufs(spi, first, n_transfers);
388 m->actual_length += total_len;
393 can_use_prepend = false;
398 spi_finalize_current_message(master);
403 /* This driver supports single master mode only. Hence
404 * CMD_DONE is the only interrupt we care about
406 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
408 struct spi_master *master = (struct spi_master *)dev_id;
409 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
412 /* Read interupts and clear them immediately */
413 intr = bcm_spi_readb(bs, SPI_INT_STATUS);
414 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
415 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
417 /* A transfer completed */
418 if (intr & SPI_INTR_CMD_DONE)
424 static size_t bcm63xx_spi_max_length(struct spi_device *spi)
426 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
428 return bs->fifo_size;
431 static const unsigned long bcm6348_spi_reg_offsets[] = {
432 [SPI_CMD] = SPI_6348_CMD,
433 [SPI_INT_STATUS] = SPI_6348_INT_STATUS,
434 [SPI_INT_MASK_ST] = SPI_6348_INT_MASK_ST,
435 [SPI_INT_MASK] = SPI_6348_INT_MASK,
436 [SPI_ST] = SPI_6348_ST,
437 [SPI_CLK_CFG] = SPI_6348_CLK_CFG,
438 [SPI_FILL_BYTE] = SPI_6348_FILL_BYTE,
439 [SPI_MSG_TAIL] = SPI_6348_MSG_TAIL,
440 [SPI_RX_TAIL] = SPI_6348_RX_TAIL,
441 [SPI_MSG_CTL] = SPI_6348_MSG_CTL,
442 [SPI_MSG_DATA] = SPI_6348_MSG_DATA,
443 [SPI_RX_DATA] = SPI_6348_RX_DATA,
444 [SPI_MSG_TYPE_SHIFT] = SPI_6348_MSG_TYPE_SHIFT,
445 [SPI_MSG_CTL_WIDTH] = SPI_6348_MSG_CTL_WIDTH,
446 [SPI_MSG_DATA_SIZE] = SPI_6348_MSG_DATA_SIZE,
449 static const unsigned long bcm6358_spi_reg_offsets[] = {
450 [SPI_CMD] = SPI_6358_CMD,
451 [SPI_INT_STATUS] = SPI_6358_INT_STATUS,
452 [SPI_INT_MASK_ST] = SPI_6358_INT_MASK_ST,
453 [SPI_INT_MASK] = SPI_6358_INT_MASK,
454 [SPI_ST] = SPI_6358_ST,
455 [SPI_CLK_CFG] = SPI_6358_CLK_CFG,
456 [SPI_FILL_BYTE] = SPI_6358_FILL_BYTE,
457 [SPI_MSG_TAIL] = SPI_6358_MSG_TAIL,
458 [SPI_RX_TAIL] = SPI_6358_RX_TAIL,
459 [SPI_MSG_CTL] = SPI_6358_MSG_CTL,
460 [SPI_MSG_DATA] = SPI_6358_MSG_DATA,
461 [SPI_RX_DATA] = SPI_6358_RX_DATA,
462 [SPI_MSG_TYPE_SHIFT] = SPI_6358_MSG_TYPE_SHIFT,
463 [SPI_MSG_CTL_WIDTH] = SPI_6358_MSG_CTL_WIDTH,
464 [SPI_MSG_DATA_SIZE] = SPI_6358_MSG_DATA_SIZE,
467 static const struct platform_device_id bcm63xx_spi_dev_match[] = {
469 .name = "bcm6348-spi",
470 .driver_data = (unsigned long)bcm6348_spi_reg_offsets,
473 .name = "bcm6358-spi",
474 .driver_data = (unsigned long)bcm6358_spi_reg_offsets,
480 static const struct of_device_id bcm63xx_spi_of_match[] = {
481 { .compatible = "brcm,bcm6348-spi", .data = &bcm6348_spi_reg_offsets },
482 { .compatible = "brcm,bcm6358-spi", .data = &bcm6358_spi_reg_offsets },
486 static int bcm63xx_spi_probe(struct platform_device *pdev)
489 const unsigned long *bcm63xx_spireg;
490 struct device *dev = &pdev->dev;
492 struct spi_master *master;
494 struct bcm63xx_spi *bs;
496 u32 num_cs = BCM63XX_SPI_MAX_CS;
497 struct reset_control *reset;
500 const struct of_device_id *match;
502 match = of_match_node(bcm63xx_spi_of_match, dev->of_node);
505 bcm63xx_spireg = match->data;
507 of_property_read_u32(dev->of_node, "num-cs", &num_cs);
508 if (num_cs > BCM63XX_SPI_MAX_CS) {
509 dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n",
511 num_cs = BCM63XX_SPI_MAX_CS;
515 } else if (pdev->id_entry->driver_data) {
516 const struct platform_device_id *match = pdev->id_entry;
518 bcm63xx_spireg = (const unsigned long *)match->driver_data;
519 bus_num = BCM63XX_SPI_BUS_NUM;
524 irq = platform_get_irq(pdev, 0);
528 clk = devm_clk_get(dev, "spi");
530 dev_err(dev, "no clock for device\n");
534 reset = devm_reset_control_get_optional_exclusive(dev, NULL);
536 return PTR_ERR(reset);
538 master = spi_alloc_master(dev, sizeof(*bs));
540 dev_err(dev, "out of memory\n");
544 bs = spi_master_get_devdata(master);
545 init_completion(&bs->done);
547 platform_set_drvdata(pdev, master);
550 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
551 bs->regs = devm_ioremap_resource(&pdev->dev, r);
552 if (IS_ERR(bs->regs)) {
553 ret = PTR_ERR(bs->regs);
559 bs->reg_offsets = bcm63xx_spireg;
560 bs->fifo_size = bs->reg_offsets[SPI_MSG_DATA_SIZE];
562 ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
565 dev_err(dev, "unable to request irq\n");
569 master->dev.of_node = dev->of_node;
570 master->bus_num = bus_num;
571 master->num_chipselect = num_cs;
572 master->transfer_one_message = bcm63xx_spi_transfer_one;
573 master->mode_bits = MODEBITS;
574 master->bits_per_word_mask = SPI_BPW_MASK(8);
575 master->max_transfer_size = bcm63xx_spi_max_length;
576 master->max_message_size = bcm63xx_spi_max_length;
577 master->auto_runtime_pm = true;
578 bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
579 bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
580 bs->tx_io = (u8 *)(bs->regs + bs->reg_offsets[SPI_MSG_DATA]);
581 bs->rx_io = (const u8 *)(bs->regs + bs->reg_offsets[SPI_RX_DATA]);
583 /* Initialize hardware */
584 ret = clk_prepare_enable(bs->clk);
588 ret = reset_control_reset(reset);
590 dev_err(dev, "unable to reset device: %d\n", ret);
591 goto out_clk_disable;
594 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
596 pm_runtime_enable(&pdev->dev);
598 /* register and we are done */
599 ret = devm_spi_register_master(dev, master);
601 dev_err(dev, "spi register failed\n");
605 dev_info(dev, "at %pr (irq %d, FIFOs size %d)\n",
606 r, irq, bs->fifo_size);
611 pm_runtime_disable(&pdev->dev);
613 clk_disable_unprepare(clk);
615 spi_master_put(master);
619 static int bcm63xx_spi_remove(struct platform_device *pdev)
621 struct spi_master *master = platform_get_drvdata(pdev);
622 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
624 /* reset spi block */
625 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
628 clk_disable_unprepare(bs->clk);
633 #ifdef CONFIG_PM_SLEEP
634 static int bcm63xx_spi_suspend(struct device *dev)
636 struct spi_master *master = dev_get_drvdata(dev);
637 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
639 spi_master_suspend(master);
641 clk_disable_unprepare(bs->clk);
646 static int bcm63xx_spi_resume(struct device *dev)
648 struct spi_master *master = dev_get_drvdata(dev);
649 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
652 ret = clk_prepare_enable(bs->clk);
656 spi_master_resume(master);
662 static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
663 SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume)
666 static struct platform_driver bcm63xx_spi_driver = {
668 .name = "bcm63xx-spi",
669 .pm = &bcm63xx_spi_pm_ops,
670 .of_match_table = bcm63xx_spi_of_match,
672 .id_table = bcm63xx_spi_dev_match,
673 .probe = bcm63xx_spi_probe,
674 .remove = bcm63xx_spi_remove,
677 module_platform_driver(bcm63xx_spi_driver);
679 MODULE_ALIAS("platform:bcm63xx_spi");
680 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
681 MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
682 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
683 MODULE_LICENSE("GPL");