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 7
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 void bcm_spi_writeb(struct bcm63xx_spi *bs,
161 u8 value, unsigned int offset)
163 writeb(value, bs->regs + bs->reg_offsets[offset]);
166 static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
167 u16 value, unsigned int offset)
169 #ifdef CONFIG_CPU_BIG_ENDIAN
170 iowrite16be(value, bs->regs + bs->reg_offsets[offset]);
172 writew(value, bs->regs + bs->reg_offsets[offset]);
176 static const unsigned int bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
177 { 20000000, SPI_CLK_20MHZ },
178 { 12500000, SPI_CLK_12_50MHZ },
179 { 6250000, SPI_CLK_6_250MHZ },
180 { 3125000, SPI_CLK_3_125MHZ },
181 { 1563000, SPI_CLK_1_563MHZ },
182 { 781000, SPI_CLK_0_781MHZ },
183 { 391000, SPI_CLK_0_391MHZ }
186 static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
187 struct spi_transfer *t)
189 struct bcm63xx_spi *bs = spi_controller_get_devdata(spi->controller);
193 /* Default to lowest clock configuration */
194 clk_cfg = SPI_CLK_0_391MHZ;
196 /* Find the closest clock configuration */
197 for (i = 0; i < SPI_CLK_MASK; i++) {
198 if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
199 clk_cfg = bcm63xx_spi_freq_table[i][1];
204 /* clear existing clock configuration bits of the register */
205 reg = bcm_spi_readb(bs, SPI_CLK_CFG);
206 reg &= ~SPI_CLK_MASK;
209 bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
210 dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
211 clk_cfg, t->speed_hz);
214 /* the spi->mode bits understood by this driver: */
215 #define MODEBITS (SPI_CPOL | SPI_CPHA)
217 static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
218 unsigned int num_transfers)
220 struct bcm63xx_spi *bs = spi_controller_get_devdata(spi->controller);
223 unsigned int i, timeout = 0, prepend_len = 0, len = 0;
224 struct spi_transfer *t = first;
228 /* Disable the CMD_DONE interrupt */
229 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
231 dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
232 t->tx_buf, t->rx_buf, t->len);
234 if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
235 prepend_len = t->len;
237 /* prepare the buffer */
238 for (i = 0; i < num_transfers; i++) {
241 memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
243 /* don't prepend more than one tx */
250 /* prepend is half-duplex write only */
257 t = list_entry(t->transfer_list.next, struct spi_transfer,
261 reinit_completion(&bs->done);
263 /* Fill in the Message control register */
264 msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
266 if (do_rx && do_tx && prepend_len == 0)
267 msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
269 msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
271 msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
273 switch (bs->msg_ctl_width) {
275 bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
278 bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
282 /* Issue the transfer */
283 cmd = SPI_CMD_START_IMMEDIATE;
284 cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
285 cmd |= (spi_get_chipselect(spi, 0) << SPI_CMD_DEVICE_ID_SHIFT);
286 bcm_spi_writew(bs, cmd, SPI_CMD);
288 /* Enable the CMD_DONE interrupt */
289 bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
291 timeout = wait_for_completion_timeout(&bs->done, HZ);
300 /* Read out all the data */
301 for (i = 0; i < num_transfers; i++) {
303 memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
305 if (t != first || prepend_len == 0)
308 t = list_entry(t->transfer_list.next, struct spi_transfer,
315 static int bcm63xx_spi_transfer_one(struct spi_controller *host,
316 struct spi_message *m)
318 struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
319 struct spi_transfer *t, *first = NULL;
320 struct spi_device *spi = m->spi;
322 unsigned int n_transfers = 0, total_len = 0;
323 bool can_use_prepend = false;
326 * This SPI controller does not support keeping CS active after a
328 * Work around this by merging as many transfers we can into one big
329 * full-duplex transfers.
331 list_for_each_entry(t, &m->transfers, transfer_list) {
338 if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
339 first->len <= BCM63XX_SPI_MAX_PREPEND)
340 can_use_prepend = true;
341 else if (can_use_prepend && t->tx_buf)
342 can_use_prepend = false;
344 /* we can only transfer one fifo worth of data */
345 if ((can_use_prepend &&
346 total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
347 (!can_use_prepend && total_len > bs->fifo_size)) {
348 dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
349 total_len, bs->fifo_size);
354 /* all combined transfers have to have the same speed */
355 if (t->speed_hz != first->speed_hz) {
356 dev_err(&spi->dev, "unable to change speed between transfers\n");
361 /* CS will be deasserted directly after transfer */
362 if (t->delay.value) {
363 dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
369 list_is_last(&t->transfer_list, &m->transfers)) {
370 /* configure adapter for a new transfer */
371 bcm63xx_spi_setup_transfer(spi, first);
374 status = bcm63xx_txrx_bufs(spi, first, n_transfers);
378 m->actual_length += total_len;
383 can_use_prepend = false;
388 spi_finalize_current_message(host);
393 /* This driver supports single host mode only. Hence
394 * CMD_DONE is the only interrupt we care about
396 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
398 struct spi_controller *host = (struct spi_controller *)dev_id;
399 struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
402 /* Read interupts and clear them immediately */
403 intr = bcm_spi_readb(bs, SPI_INT_STATUS);
404 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
405 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
407 /* A transfer completed */
408 if (intr & SPI_INTR_CMD_DONE)
414 static size_t bcm63xx_spi_max_length(struct spi_device *spi)
416 struct bcm63xx_spi *bs = spi_controller_get_devdata(spi->controller);
418 return bs->fifo_size;
421 static const unsigned long bcm6348_spi_reg_offsets[] = {
422 [SPI_CMD] = SPI_6348_CMD,
423 [SPI_INT_STATUS] = SPI_6348_INT_STATUS,
424 [SPI_INT_MASK_ST] = SPI_6348_INT_MASK_ST,
425 [SPI_INT_MASK] = SPI_6348_INT_MASK,
426 [SPI_ST] = SPI_6348_ST,
427 [SPI_CLK_CFG] = SPI_6348_CLK_CFG,
428 [SPI_FILL_BYTE] = SPI_6348_FILL_BYTE,
429 [SPI_MSG_TAIL] = SPI_6348_MSG_TAIL,
430 [SPI_RX_TAIL] = SPI_6348_RX_TAIL,
431 [SPI_MSG_CTL] = SPI_6348_MSG_CTL,
432 [SPI_MSG_DATA] = SPI_6348_MSG_DATA,
433 [SPI_RX_DATA] = SPI_6348_RX_DATA,
434 [SPI_MSG_TYPE_SHIFT] = SPI_6348_MSG_TYPE_SHIFT,
435 [SPI_MSG_CTL_WIDTH] = SPI_6348_MSG_CTL_WIDTH,
436 [SPI_MSG_DATA_SIZE] = SPI_6348_MSG_DATA_SIZE,
439 static const unsigned long bcm6358_spi_reg_offsets[] = {
440 [SPI_CMD] = SPI_6358_CMD,
441 [SPI_INT_STATUS] = SPI_6358_INT_STATUS,
442 [SPI_INT_MASK_ST] = SPI_6358_INT_MASK_ST,
443 [SPI_INT_MASK] = SPI_6358_INT_MASK,
444 [SPI_ST] = SPI_6358_ST,
445 [SPI_CLK_CFG] = SPI_6358_CLK_CFG,
446 [SPI_FILL_BYTE] = SPI_6358_FILL_BYTE,
447 [SPI_MSG_TAIL] = SPI_6358_MSG_TAIL,
448 [SPI_RX_TAIL] = SPI_6358_RX_TAIL,
449 [SPI_MSG_CTL] = SPI_6358_MSG_CTL,
450 [SPI_MSG_DATA] = SPI_6358_MSG_DATA,
451 [SPI_RX_DATA] = SPI_6358_RX_DATA,
452 [SPI_MSG_TYPE_SHIFT] = SPI_6358_MSG_TYPE_SHIFT,
453 [SPI_MSG_CTL_WIDTH] = SPI_6358_MSG_CTL_WIDTH,
454 [SPI_MSG_DATA_SIZE] = SPI_6358_MSG_DATA_SIZE,
457 static const struct platform_device_id bcm63xx_spi_dev_match[] = {
459 .name = "bcm6348-spi",
460 .driver_data = (unsigned long)bcm6348_spi_reg_offsets,
463 .name = "bcm6358-spi",
464 .driver_data = (unsigned long)bcm6358_spi_reg_offsets,
470 static const struct of_device_id bcm63xx_spi_of_match[] = {
471 { .compatible = "brcm,bcm6348-spi", .data = &bcm6348_spi_reg_offsets },
472 { .compatible = "brcm,bcm6358-spi", .data = &bcm6358_spi_reg_offsets },
476 static int bcm63xx_spi_probe(struct platform_device *pdev)
479 const unsigned long *bcm63xx_spireg;
480 struct device *dev = &pdev->dev;
482 struct spi_controller *host;
484 struct bcm63xx_spi *bs;
486 u32 num_cs = BCM63XX_SPI_MAX_CS;
487 struct reset_control *reset;
490 const struct of_device_id *match;
492 match = of_match_node(bcm63xx_spi_of_match, dev->of_node);
495 bcm63xx_spireg = match->data;
497 of_property_read_u32(dev->of_node, "num-cs", &num_cs);
498 if (num_cs > BCM63XX_SPI_MAX_CS) {
499 dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n",
501 num_cs = BCM63XX_SPI_MAX_CS;
505 } else if (pdev->id_entry->driver_data) {
506 const struct platform_device_id *match = pdev->id_entry;
508 bcm63xx_spireg = (const unsigned long *)match->driver_data;
509 bus_num = BCM63XX_SPI_BUS_NUM;
514 irq = platform_get_irq(pdev, 0);
518 clk = devm_clk_get(dev, "spi");
520 dev_err(dev, "no clock for device\n");
524 reset = devm_reset_control_get_optional_exclusive(dev, NULL);
526 return PTR_ERR(reset);
528 host = spi_alloc_host(dev, sizeof(*bs));
530 dev_err(dev, "out of memory\n");
534 bs = spi_controller_get_devdata(host);
535 init_completion(&bs->done);
537 platform_set_drvdata(pdev, host);
540 bs->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &r);
541 if (IS_ERR(bs->regs)) {
542 ret = PTR_ERR(bs->regs);
548 bs->reg_offsets = bcm63xx_spireg;
549 bs->fifo_size = bs->reg_offsets[SPI_MSG_DATA_SIZE];
551 ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
554 dev_err(dev, "unable to request irq\n");
558 host->dev.of_node = dev->of_node;
559 host->bus_num = bus_num;
560 host->num_chipselect = num_cs;
561 host->transfer_one_message = bcm63xx_spi_transfer_one;
562 host->mode_bits = MODEBITS;
563 host->bits_per_word_mask = SPI_BPW_MASK(8);
564 host->max_transfer_size = bcm63xx_spi_max_length;
565 host->max_message_size = bcm63xx_spi_max_length;
566 host->auto_runtime_pm = true;
567 bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
568 bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
569 bs->tx_io = (u8 *)(bs->regs + bs->reg_offsets[SPI_MSG_DATA]);
570 bs->rx_io = (const u8 *)(bs->regs + bs->reg_offsets[SPI_RX_DATA]);
572 /* Initialize hardware */
573 ret = clk_prepare_enable(bs->clk);
577 ret = reset_control_reset(reset);
579 dev_err(dev, "unable to reset device: %d\n", ret);
580 goto out_clk_disable;
583 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
585 pm_runtime_enable(&pdev->dev);
587 /* register and we are done */
588 ret = devm_spi_register_controller(dev, host);
590 dev_err(dev, "spi register failed\n");
594 dev_info(dev, "at %pr (irq %d, FIFOs size %d)\n",
595 r, irq, bs->fifo_size);
600 pm_runtime_disable(&pdev->dev);
602 clk_disable_unprepare(clk);
604 spi_controller_put(host);
608 static void bcm63xx_spi_remove(struct platform_device *pdev)
610 struct spi_controller *host = platform_get_drvdata(pdev);
611 struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
613 /* reset spi block */
614 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
617 clk_disable_unprepare(bs->clk);
620 static int bcm63xx_spi_suspend(struct device *dev)
622 struct spi_controller *host = dev_get_drvdata(dev);
623 struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
625 spi_controller_suspend(host);
627 clk_disable_unprepare(bs->clk);
632 static int bcm63xx_spi_resume(struct device *dev)
634 struct spi_controller *host = dev_get_drvdata(dev);
635 struct bcm63xx_spi *bs = spi_controller_get_devdata(host);
638 ret = clk_prepare_enable(bs->clk);
642 spi_controller_resume(host);
647 static DEFINE_SIMPLE_DEV_PM_OPS(bcm63xx_spi_pm_ops, bcm63xx_spi_suspend, bcm63xx_spi_resume);
649 static struct platform_driver bcm63xx_spi_driver = {
651 .name = "bcm63xx-spi",
652 .pm = &bcm63xx_spi_pm_ops,
653 .of_match_table = bcm63xx_spi_of_match,
655 .id_table = bcm63xx_spi_dev_match,
656 .probe = bcm63xx_spi_probe,
657 .remove_new = bcm63xx_spi_remove,
660 module_platform_driver(bcm63xx_spi_driver);
662 MODULE_ALIAS("platform:bcm63xx_spi");
663 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
664 MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
665 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
666 MODULE_LICENSE("GPL");