1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Broadcom BCM63xx SPI controller support
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>
22 /* BCM 6338/6348 SPI core */
23 #define SPI_6348_RSET_SIZE 64
24 #define SPI_6348_CMD 0x00 /* 16-bits register */
25 #define SPI_6348_INT_STATUS 0x02
26 #define SPI_6348_INT_MASK_ST 0x03
27 #define SPI_6348_INT_MASK 0x04
28 #define SPI_6348_ST 0x05
29 #define SPI_6348_CLK_CFG 0x06
30 #define SPI_6348_FILL_BYTE 0x07
31 #define SPI_6348_MSG_TAIL 0x09
32 #define SPI_6348_RX_TAIL 0x0b
33 #define SPI_6348_MSG_CTL 0x40 /* 8-bits register */
34 #define SPI_6348_MSG_CTL_WIDTH 8
35 #define SPI_6348_MSG_DATA 0x41
36 #define SPI_6348_MSG_DATA_SIZE 0x3f
37 #define SPI_6348_RX_DATA 0x80
38 #define SPI_6348_RX_DATA_SIZE 0x3f
40 /* BCM 3368/6358/6262/6368 SPI core */
41 #define SPI_6358_RSET_SIZE 1804
42 #define SPI_6358_MSG_CTL 0x00 /* 16-bits register */
43 #define SPI_6358_MSG_CTL_WIDTH 16
44 #define SPI_6358_MSG_DATA 0x02
45 #define SPI_6358_MSG_DATA_SIZE 0x21e
46 #define SPI_6358_RX_DATA 0x400
47 #define SPI_6358_RX_DATA_SIZE 0x220
48 #define SPI_6358_CMD 0x700 /* 16-bits register */
49 #define SPI_6358_INT_STATUS 0x702
50 #define SPI_6358_INT_MASK_ST 0x703
51 #define SPI_6358_INT_MASK 0x704
52 #define SPI_6358_ST 0x705
53 #define SPI_6358_CLK_CFG 0x706
54 #define SPI_6358_FILL_BYTE 0x707
55 #define SPI_6358_MSG_TAIL 0x709
56 #define SPI_6358_RX_TAIL 0x70B
58 /* Shared SPI definitions */
60 /* Message configuration */
61 #define SPI_FD_RW 0x00
64 #define SPI_BYTE_CNT_SHIFT 0
65 #define SPI_6348_MSG_TYPE_SHIFT 6
66 #define SPI_6358_MSG_TYPE_SHIFT 14
69 #define SPI_CMD_NOOP 0x00
70 #define SPI_CMD_SOFT_RESET 0x01
71 #define SPI_CMD_HARD_RESET 0x02
72 #define SPI_CMD_START_IMMEDIATE 0x03
73 #define SPI_CMD_COMMAND_SHIFT 0
74 #define SPI_CMD_COMMAND_MASK 0x000f
75 #define SPI_CMD_DEVICE_ID_SHIFT 4
76 #define SPI_CMD_PREPEND_BYTE_CNT_SHIFT 8
77 #define SPI_CMD_ONE_BYTE_SHIFT 11
78 #define SPI_CMD_ONE_WIRE_SHIFT 12
79 #define SPI_DEV_ID_0 0
80 #define SPI_DEV_ID_1 1
81 #define SPI_DEV_ID_2 2
82 #define SPI_DEV_ID_3 3
85 #define SPI_INTR_CMD_DONE 0x01
86 #define SPI_INTR_RX_OVERFLOW 0x02
87 #define SPI_INTR_TX_UNDERFLOW 0x04
88 #define SPI_INTR_TX_OVERFLOW 0x08
89 #define SPI_INTR_RX_UNDERFLOW 0x10
90 #define SPI_INTR_CLEAR_ALL 0x1f
93 #define SPI_RX_EMPTY 0x02
94 #define SPI_CMD_BUSY 0x04
95 #define SPI_SERIAL_BUSY 0x08
97 /* Clock configuration */
98 #define SPI_CLK_20MHZ 0x00
99 #define SPI_CLK_0_391MHZ 0x01
100 #define SPI_CLK_0_781MHZ 0x02 /* default */
101 #define SPI_CLK_1_563MHZ 0x03
102 #define SPI_CLK_3_125MHZ 0x04
103 #define SPI_CLK_6_250MHZ 0x05
104 #define SPI_CLK_12_50MHZ 0x06
105 #define SPI_CLK_MASK 0x07
106 #define SPI_SSOFFTIME_MASK 0x38
107 #define SPI_SSOFFTIME_SHIFT 3
108 #define SPI_BYTE_SWAP 0x80
110 enum bcm63xx_regs_spi {
128 #define BCM63XX_SPI_MAX_PREPEND 15
130 #define BCM63XX_SPI_MAX_CS 8
131 #define BCM63XX_SPI_BUS_NUM 0
134 struct completion done;
140 const unsigned long *reg_offsets;
141 unsigned int fifo_size;
142 unsigned int msg_type_shift;
143 unsigned int msg_ctl_width;
147 const u8 __iomem *rx_io;
150 struct platform_device *pdev;
153 static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
156 return readb(bs->regs + bs->reg_offsets[offset]);
159 static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
162 #ifdef CONFIG_CPU_BIG_ENDIAN
163 return ioread16be(bs->regs + bs->reg_offsets[offset]);
165 return readw(bs->regs + bs->reg_offsets[offset]);
169 static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
170 u8 value, unsigned int offset)
172 writeb(value, bs->regs + bs->reg_offsets[offset]);
175 static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
176 u16 value, unsigned int offset)
178 #ifdef CONFIG_CPU_BIG_ENDIAN
179 iowrite16be(value, bs->regs + bs->reg_offsets[offset]);
181 writew(value, bs->regs + bs->reg_offsets[offset]);
185 static const unsigned int bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
186 { 20000000, SPI_CLK_20MHZ },
187 { 12500000, SPI_CLK_12_50MHZ },
188 { 6250000, SPI_CLK_6_250MHZ },
189 { 3125000, SPI_CLK_3_125MHZ },
190 { 1563000, SPI_CLK_1_563MHZ },
191 { 781000, SPI_CLK_0_781MHZ },
192 { 391000, SPI_CLK_0_391MHZ }
195 static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
196 struct spi_transfer *t)
198 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
202 /* Default to lowest clock configuration */
203 clk_cfg = SPI_CLK_0_391MHZ;
205 /* Find the closest clock configuration */
206 for (i = 0; i < SPI_CLK_MASK; i++) {
207 if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
208 clk_cfg = bcm63xx_spi_freq_table[i][1];
213 /* clear existing clock configuration bits of the register */
214 reg = bcm_spi_readb(bs, SPI_CLK_CFG);
215 reg &= ~SPI_CLK_MASK;
218 bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
219 dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
220 clk_cfg, t->speed_hz);
223 /* the spi->mode bits understood by this driver: */
224 #define MODEBITS (SPI_CPOL | SPI_CPHA)
226 static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
227 unsigned int num_transfers)
229 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
232 unsigned int i, timeout = 0, prepend_len = 0, len = 0;
233 struct spi_transfer *t = first;
237 /* Disable the CMD_DONE interrupt */
238 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
240 dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
241 t->tx_buf, t->rx_buf, t->len);
243 if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
244 prepend_len = t->len;
246 /* prepare the buffer */
247 for (i = 0; i < num_transfers; i++) {
250 memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
252 /* don't prepend more than one tx */
259 /* prepend is half-duplex write only */
266 t = list_entry(t->transfer_list.next, struct spi_transfer,
270 reinit_completion(&bs->done);
272 /* Fill in the Message control register */
273 msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
275 if (do_rx && do_tx && prepend_len == 0)
276 msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
278 msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
280 msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
282 switch (bs->msg_ctl_width) {
284 bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
287 bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
291 /* Issue the transfer */
292 cmd = SPI_CMD_START_IMMEDIATE;
293 cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
294 cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
295 bcm_spi_writew(bs, cmd, SPI_CMD);
297 /* Enable the CMD_DONE interrupt */
298 bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
300 timeout = wait_for_completion_timeout(&bs->done, HZ);
309 /* Read out all the data */
310 for (i = 0; i < num_transfers; i++) {
312 memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
314 if (t != first || prepend_len == 0)
317 t = list_entry(t->transfer_list.next, struct spi_transfer,
324 static int bcm63xx_spi_transfer_one(struct spi_master *master,
325 struct spi_message *m)
327 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
328 struct spi_transfer *t, *first = NULL;
329 struct spi_device *spi = m->spi;
331 unsigned int n_transfers = 0, total_len = 0;
332 bool can_use_prepend = false;
335 * This SPI controller does not support keeping CS active after a
337 * Work around this by merging as many transfers we can into one big
338 * full-duplex transfers.
340 list_for_each_entry(t, &m->transfers, transfer_list) {
347 if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
348 first->len <= BCM63XX_SPI_MAX_PREPEND)
349 can_use_prepend = true;
350 else if (can_use_prepend && t->tx_buf)
351 can_use_prepend = false;
353 /* we can only transfer one fifo worth of data */
354 if ((can_use_prepend &&
355 total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
356 (!can_use_prepend && total_len > bs->fifo_size)) {
357 dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
358 total_len, bs->fifo_size);
363 /* all combined transfers have to have the same speed */
364 if (t->speed_hz != first->speed_hz) {
365 dev_err(&spi->dev, "unable to change speed between transfers\n");
370 /* CS will be deasserted directly after transfer */
371 if (t->delay_usecs || t->delay.value) {
372 dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
378 list_is_last(&t->transfer_list, &m->transfers)) {
379 /* configure adapter for a new transfer */
380 bcm63xx_spi_setup_transfer(spi, first);
383 status = bcm63xx_txrx_bufs(spi, first, n_transfers);
387 m->actual_length += total_len;
392 can_use_prepend = false;
397 spi_finalize_current_message(master);
402 /* This driver supports single master mode only. Hence
403 * CMD_DONE is the only interrupt we care about
405 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
407 struct spi_master *master = (struct spi_master *)dev_id;
408 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
411 /* Read interupts and clear them immediately */
412 intr = bcm_spi_readb(bs, SPI_INT_STATUS);
413 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
414 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
416 /* A transfer completed */
417 if (intr & SPI_INTR_CMD_DONE)
423 static size_t bcm63xx_spi_max_length(struct spi_device *spi)
425 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
427 return bs->fifo_size;
430 static const unsigned long bcm6348_spi_reg_offsets[] = {
431 [SPI_CMD] = SPI_6348_CMD,
432 [SPI_INT_STATUS] = SPI_6348_INT_STATUS,
433 [SPI_INT_MASK_ST] = SPI_6348_INT_MASK_ST,
434 [SPI_INT_MASK] = SPI_6348_INT_MASK,
435 [SPI_ST] = SPI_6348_ST,
436 [SPI_CLK_CFG] = SPI_6348_CLK_CFG,
437 [SPI_FILL_BYTE] = SPI_6348_FILL_BYTE,
438 [SPI_MSG_TAIL] = SPI_6348_MSG_TAIL,
439 [SPI_RX_TAIL] = SPI_6348_RX_TAIL,
440 [SPI_MSG_CTL] = SPI_6348_MSG_CTL,
441 [SPI_MSG_DATA] = SPI_6348_MSG_DATA,
442 [SPI_RX_DATA] = SPI_6348_RX_DATA,
443 [SPI_MSG_TYPE_SHIFT] = SPI_6348_MSG_TYPE_SHIFT,
444 [SPI_MSG_CTL_WIDTH] = SPI_6348_MSG_CTL_WIDTH,
445 [SPI_MSG_DATA_SIZE] = SPI_6348_MSG_DATA_SIZE,
448 static const unsigned long bcm6358_spi_reg_offsets[] = {
449 [SPI_CMD] = SPI_6358_CMD,
450 [SPI_INT_STATUS] = SPI_6358_INT_STATUS,
451 [SPI_INT_MASK_ST] = SPI_6358_INT_MASK_ST,
452 [SPI_INT_MASK] = SPI_6358_INT_MASK,
453 [SPI_ST] = SPI_6358_ST,
454 [SPI_CLK_CFG] = SPI_6358_CLK_CFG,
455 [SPI_FILL_BYTE] = SPI_6358_FILL_BYTE,
456 [SPI_MSG_TAIL] = SPI_6358_MSG_TAIL,
457 [SPI_RX_TAIL] = SPI_6358_RX_TAIL,
458 [SPI_MSG_CTL] = SPI_6358_MSG_CTL,
459 [SPI_MSG_DATA] = SPI_6358_MSG_DATA,
460 [SPI_RX_DATA] = SPI_6358_RX_DATA,
461 [SPI_MSG_TYPE_SHIFT] = SPI_6358_MSG_TYPE_SHIFT,
462 [SPI_MSG_CTL_WIDTH] = SPI_6358_MSG_CTL_WIDTH,
463 [SPI_MSG_DATA_SIZE] = SPI_6358_MSG_DATA_SIZE,
466 static const struct platform_device_id bcm63xx_spi_dev_match[] = {
468 .name = "bcm6348-spi",
469 .driver_data = (unsigned long)bcm6348_spi_reg_offsets,
472 .name = "bcm6358-spi",
473 .driver_data = (unsigned long)bcm6358_spi_reg_offsets,
479 static const struct of_device_id bcm63xx_spi_of_match[] = {
480 { .compatible = "brcm,bcm6348-spi", .data = &bcm6348_spi_reg_offsets },
481 { .compatible = "brcm,bcm6358-spi", .data = &bcm6358_spi_reg_offsets },
485 static int bcm63xx_spi_probe(struct platform_device *pdev)
488 const unsigned long *bcm63xx_spireg;
489 struct device *dev = &pdev->dev;
491 struct spi_master *master;
493 struct bcm63xx_spi *bs;
495 u32 num_cs = BCM63XX_SPI_MAX_CS;
498 const struct of_device_id *match;
500 match = of_match_node(bcm63xx_spi_of_match, dev->of_node);
503 bcm63xx_spireg = match->data;
505 of_property_read_u32(dev->of_node, "num-cs", &num_cs);
506 if (num_cs > BCM63XX_SPI_MAX_CS) {
507 dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n",
509 num_cs = BCM63XX_SPI_MAX_CS;
513 } else if (pdev->id_entry->driver_data) {
514 const struct platform_device_id *match = pdev->id_entry;
516 bcm63xx_spireg = (const unsigned long *)match->driver_data;
517 bus_num = BCM63XX_SPI_BUS_NUM;
522 irq = platform_get_irq(pdev, 0);
526 clk = devm_clk_get(dev, "spi");
528 dev_err(dev, "no clock for device\n");
532 master = spi_alloc_master(dev, sizeof(*bs));
534 dev_err(dev, "out of memory\n");
538 bs = spi_master_get_devdata(master);
539 init_completion(&bs->done);
541 platform_set_drvdata(pdev, master);
544 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
545 bs->regs = devm_ioremap_resource(&pdev->dev, r);
546 if (IS_ERR(bs->regs)) {
547 ret = PTR_ERR(bs->regs);
553 bs->reg_offsets = bcm63xx_spireg;
554 bs->fifo_size = bs->reg_offsets[SPI_MSG_DATA_SIZE];
556 ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
559 dev_err(dev, "unable to request irq\n");
563 master->dev.of_node = dev->of_node;
564 master->bus_num = bus_num;
565 master->num_chipselect = num_cs;
566 master->transfer_one_message = bcm63xx_spi_transfer_one;
567 master->mode_bits = MODEBITS;
568 master->bits_per_word_mask = SPI_BPW_MASK(8);
569 master->max_transfer_size = bcm63xx_spi_max_length;
570 master->max_message_size = bcm63xx_spi_max_length;
571 master->auto_runtime_pm = true;
572 bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
573 bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
574 bs->tx_io = (u8 *)(bs->regs + bs->reg_offsets[SPI_MSG_DATA]);
575 bs->rx_io = (const u8 *)(bs->regs + bs->reg_offsets[SPI_RX_DATA]);
577 /* Initialize hardware */
578 ret = clk_prepare_enable(bs->clk);
582 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
584 /* register and we are done */
585 ret = devm_spi_register_master(dev, master);
587 dev_err(dev, "spi register failed\n");
588 goto out_clk_disable;
591 dev_info(dev, "at %pr (irq %d, FIFOs size %d)\n",
592 r, irq, bs->fifo_size);
597 clk_disable_unprepare(clk);
599 spi_master_put(master);
603 static int bcm63xx_spi_remove(struct platform_device *pdev)
605 struct spi_master *master = platform_get_drvdata(pdev);
606 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
608 /* reset spi block */
609 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
612 clk_disable_unprepare(bs->clk);
617 #ifdef CONFIG_PM_SLEEP
618 static int bcm63xx_spi_suspend(struct device *dev)
620 struct spi_master *master = dev_get_drvdata(dev);
621 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
623 spi_master_suspend(master);
625 clk_disable_unprepare(bs->clk);
630 static int bcm63xx_spi_resume(struct device *dev)
632 struct spi_master *master = dev_get_drvdata(dev);
633 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
636 ret = clk_prepare_enable(bs->clk);
640 spi_master_resume(master);
646 static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
647 SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume)
650 static struct platform_driver bcm63xx_spi_driver = {
652 .name = "bcm63xx-spi",
653 .pm = &bcm63xx_spi_pm_ops,
654 .of_match_table = bcm63xx_spi_of_match,
656 .id_table = bcm63xx_spi_dev_match,
657 .probe = bcm63xx_spi_probe,
658 .remove = bcm63xx_spi_remove,
661 module_platform_driver(bcm63xx_spi_driver);
663 MODULE_ALIAS("platform:bcm63xx_spi");
666 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
667 MODULE_LICENSE("GPL");