2 * Broadcom BCM63xx SPI controller support
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/kernel.h>
19 #include <linux/clk.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/delay.h>
24 #include <linux/interrupt.h>
25 #include <linux/spi/spi.h>
26 #include <linux/completion.h>
27 #include <linux/err.h>
28 #include <linux/pm_runtime.h>
31 /* BCM 6338/6348 SPI core */
32 #define SPI_6348_RSET_SIZE 64
33 #define SPI_6348_CMD 0x00 /* 16-bits register */
34 #define SPI_6348_INT_STATUS 0x02
35 #define SPI_6348_INT_MASK_ST 0x03
36 #define SPI_6348_INT_MASK 0x04
37 #define SPI_6348_ST 0x05
38 #define SPI_6348_CLK_CFG 0x06
39 #define SPI_6348_FILL_BYTE 0x07
40 #define SPI_6348_MSG_TAIL 0x09
41 #define SPI_6348_RX_TAIL 0x0b
42 #define SPI_6348_MSG_CTL 0x40 /* 8-bits register */
43 #define SPI_6348_MSG_CTL_WIDTH 8
44 #define SPI_6348_MSG_DATA 0x41
45 #define SPI_6348_MSG_DATA_SIZE 0x3f
46 #define SPI_6348_RX_DATA 0x80
47 #define SPI_6348_RX_DATA_SIZE 0x3f
49 /* BCM 3368/6358/6262/6368 SPI core */
50 #define SPI_6358_RSET_SIZE 1804
51 #define SPI_6358_MSG_CTL 0x00 /* 16-bits register */
52 #define SPI_6358_MSG_CTL_WIDTH 16
53 #define SPI_6358_MSG_DATA 0x02
54 #define SPI_6358_MSG_DATA_SIZE 0x21e
55 #define SPI_6358_RX_DATA 0x400
56 #define SPI_6358_RX_DATA_SIZE 0x220
57 #define SPI_6358_CMD 0x700 /* 16-bits register */
58 #define SPI_6358_INT_STATUS 0x702
59 #define SPI_6358_INT_MASK_ST 0x703
60 #define SPI_6358_INT_MASK 0x704
61 #define SPI_6358_ST 0x705
62 #define SPI_6358_CLK_CFG 0x706
63 #define SPI_6358_FILL_BYTE 0x707
64 #define SPI_6358_MSG_TAIL 0x709
65 #define SPI_6358_RX_TAIL 0x70B
67 /* Shared SPI definitions */
69 /* Message configuration */
70 #define SPI_FD_RW 0x00
73 #define SPI_BYTE_CNT_SHIFT 0
74 #define SPI_6348_MSG_TYPE_SHIFT 6
75 #define SPI_6358_MSG_TYPE_SHIFT 14
78 #define SPI_CMD_NOOP 0x00
79 #define SPI_CMD_SOFT_RESET 0x01
80 #define SPI_CMD_HARD_RESET 0x02
81 #define SPI_CMD_START_IMMEDIATE 0x03
82 #define SPI_CMD_COMMAND_SHIFT 0
83 #define SPI_CMD_COMMAND_MASK 0x000f
84 #define SPI_CMD_DEVICE_ID_SHIFT 4
85 #define SPI_CMD_PREPEND_BYTE_CNT_SHIFT 8
86 #define SPI_CMD_ONE_BYTE_SHIFT 11
87 #define SPI_CMD_ONE_WIRE_SHIFT 12
88 #define SPI_DEV_ID_0 0
89 #define SPI_DEV_ID_1 1
90 #define SPI_DEV_ID_2 2
91 #define SPI_DEV_ID_3 3
94 #define SPI_INTR_CMD_DONE 0x01
95 #define SPI_INTR_RX_OVERFLOW 0x02
96 #define SPI_INTR_TX_UNDERFLOW 0x04
97 #define SPI_INTR_TX_OVERFLOW 0x08
98 #define SPI_INTR_RX_UNDERFLOW 0x10
99 #define SPI_INTR_CLEAR_ALL 0x1f
102 #define SPI_RX_EMPTY 0x02
103 #define SPI_CMD_BUSY 0x04
104 #define SPI_SERIAL_BUSY 0x08
106 /* Clock configuration */
107 #define SPI_CLK_20MHZ 0x00
108 #define SPI_CLK_0_391MHZ 0x01
109 #define SPI_CLK_0_781MHZ 0x02 /* default */
110 #define SPI_CLK_1_563MHZ 0x03
111 #define SPI_CLK_3_125MHZ 0x04
112 #define SPI_CLK_6_250MHZ 0x05
113 #define SPI_CLK_12_50MHZ 0x06
114 #define SPI_CLK_MASK 0x07
115 #define SPI_SSOFFTIME_MASK 0x38
116 #define SPI_SSOFFTIME_SHIFT 3
117 #define SPI_BYTE_SWAP 0x80
119 enum bcm63xx_regs_spi {
137 #define BCM63XX_SPI_MAX_PREPEND 15
139 #define BCM63XX_SPI_MAX_CS 8
140 #define BCM63XX_SPI_BUS_NUM 0
143 struct completion done;
149 const unsigned long *reg_offsets;
150 unsigned int fifo_size;
151 unsigned int msg_type_shift;
152 unsigned int msg_ctl_width;
156 const u8 __iomem *rx_io;
159 struct platform_device *pdev;
162 static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
165 return readb(bs->regs + bs->reg_offsets[offset]);
168 static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
171 #ifdef CONFIG_CPU_BIG_ENDIAN
172 return ioread16be(bs->regs + bs->reg_offsets[offset]);
174 return readw(bs->regs + bs->reg_offsets[offset]);
178 static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
179 u8 value, unsigned int offset)
181 writeb(value, bs->regs + bs->reg_offsets[offset]);
184 static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
185 u16 value, unsigned int offset)
187 #ifdef CONFIG_CPU_BIG_ENDIAN
188 iowrite16be(value, bs->regs + bs->reg_offsets[offset]);
190 writew(value, bs->regs + bs->reg_offsets[offset]);
194 static const unsigned int bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
195 { 20000000, SPI_CLK_20MHZ },
196 { 12500000, SPI_CLK_12_50MHZ },
197 { 6250000, SPI_CLK_6_250MHZ },
198 { 3125000, SPI_CLK_3_125MHZ },
199 { 1563000, SPI_CLK_1_563MHZ },
200 { 781000, SPI_CLK_0_781MHZ },
201 { 391000, SPI_CLK_0_391MHZ }
204 static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
205 struct spi_transfer *t)
207 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
211 /* Default to lowest clock configuration */
212 clk_cfg = SPI_CLK_0_391MHZ;
214 /* Find the closest clock configuration */
215 for (i = 0; i < SPI_CLK_MASK; i++) {
216 if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
217 clk_cfg = bcm63xx_spi_freq_table[i][1];
222 /* clear existing clock configuration bits of the register */
223 reg = bcm_spi_readb(bs, SPI_CLK_CFG);
224 reg &= ~SPI_CLK_MASK;
227 bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
228 dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
229 clk_cfg, t->speed_hz);
232 /* the spi->mode bits understood by this driver: */
233 #define MODEBITS (SPI_CPOL | SPI_CPHA)
235 static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
236 unsigned int num_transfers)
238 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
241 unsigned int i, timeout = 0, prepend_len = 0, len = 0;
242 struct spi_transfer *t = first;
246 /* Disable the CMD_DONE interrupt */
247 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
249 dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
250 t->tx_buf, t->rx_buf, t->len);
252 if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
253 prepend_len = t->len;
255 /* prepare the buffer */
256 for (i = 0; i < num_transfers; i++) {
259 memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
261 /* don't prepend more than one tx */
268 /* prepend is half-duplex write only */
275 t = list_entry(t->transfer_list.next, struct spi_transfer,
279 reinit_completion(&bs->done);
281 /* Fill in the Message control register */
282 msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
284 if (do_rx && do_tx && prepend_len == 0)
285 msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
287 msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
289 msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
291 switch (bs->msg_ctl_width) {
293 bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
296 bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
300 /* Issue the transfer */
301 cmd = SPI_CMD_START_IMMEDIATE;
302 cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
303 cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
304 bcm_spi_writew(bs, cmd, SPI_CMD);
306 /* Enable the CMD_DONE interrupt */
307 bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
309 timeout = wait_for_completion_timeout(&bs->done, HZ);
318 /* Read out all the data */
319 for (i = 0; i < num_transfers; i++) {
321 memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
323 if (t != first || prepend_len == 0)
326 t = list_entry(t->transfer_list.next, struct spi_transfer,
333 static int bcm63xx_spi_transfer_one(struct spi_master *master,
334 struct spi_message *m)
336 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
337 struct spi_transfer *t, *first = NULL;
338 struct spi_device *spi = m->spi;
340 unsigned int n_transfers = 0, total_len = 0;
341 bool can_use_prepend = false;
344 * This SPI controller does not support keeping CS active after a
346 * Work around this by merging as many transfers we can into one big
347 * full-duplex transfers.
349 list_for_each_entry(t, &m->transfers, transfer_list) {
356 if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
357 first->len <= BCM63XX_SPI_MAX_PREPEND)
358 can_use_prepend = true;
359 else if (can_use_prepend && t->tx_buf)
360 can_use_prepend = false;
362 /* we can only transfer one fifo worth of data */
363 if ((can_use_prepend &&
364 total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
365 (!can_use_prepend && total_len > bs->fifo_size)) {
366 dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
367 total_len, bs->fifo_size);
372 /* all combined transfers have to have the same speed */
373 if (t->speed_hz != first->speed_hz) {
374 dev_err(&spi->dev, "unable to change speed between transfers\n");
379 /* CS will be deasserted directly after transfer */
380 if (t->delay_usecs) {
381 dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
387 list_is_last(&t->transfer_list, &m->transfers)) {
388 /* configure adapter for a new transfer */
389 bcm63xx_spi_setup_transfer(spi, first);
392 status = bcm63xx_txrx_bufs(spi, first, n_transfers);
396 m->actual_length += total_len;
401 can_use_prepend = false;
406 spi_finalize_current_message(master);
411 /* This driver supports single master mode only. Hence
412 * CMD_DONE is the only interrupt we care about
414 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
416 struct spi_master *master = (struct spi_master *)dev_id;
417 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
420 /* Read interupts and clear them immediately */
421 intr = bcm_spi_readb(bs, SPI_INT_STATUS);
422 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
423 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
425 /* A transfer completed */
426 if (intr & SPI_INTR_CMD_DONE)
432 static size_t bcm63xx_spi_max_length(struct spi_device *spi)
434 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
436 return bs->fifo_size;
439 static const unsigned long bcm6348_spi_reg_offsets[] = {
440 [SPI_CMD] = SPI_6348_CMD,
441 [SPI_INT_STATUS] = SPI_6348_INT_STATUS,
442 [SPI_INT_MASK_ST] = SPI_6348_INT_MASK_ST,
443 [SPI_INT_MASK] = SPI_6348_INT_MASK,
444 [SPI_ST] = SPI_6348_ST,
445 [SPI_CLK_CFG] = SPI_6348_CLK_CFG,
446 [SPI_FILL_BYTE] = SPI_6348_FILL_BYTE,
447 [SPI_MSG_TAIL] = SPI_6348_MSG_TAIL,
448 [SPI_RX_TAIL] = SPI_6348_RX_TAIL,
449 [SPI_MSG_CTL] = SPI_6348_MSG_CTL,
450 [SPI_MSG_DATA] = SPI_6348_MSG_DATA,
451 [SPI_RX_DATA] = SPI_6348_RX_DATA,
452 [SPI_MSG_TYPE_SHIFT] = SPI_6348_MSG_TYPE_SHIFT,
453 [SPI_MSG_CTL_WIDTH] = SPI_6348_MSG_CTL_WIDTH,
454 [SPI_MSG_DATA_SIZE] = SPI_6348_MSG_DATA_SIZE,
457 static const unsigned long bcm6358_spi_reg_offsets[] = {
458 [SPI_CMD] = SPI_6358_CMD,
459 [SPI_INT_STATUS] = SPI_6358_INT_STATUS,
460 [SPI_INT_MASK_ST] = SPI_6358_INT_MASK_ST,
461 [SPI_INT_MASK] = SPI_6358_INT_MASK,
462 [SPI_ST] = SPI_6358_ST,
463 [SPI_CLK_CFG] = SPI_6358_CLK_CFG,
464 [SPI_FILL_BYTE] = SPI_6358_FILL_BYTE,
465 [SPI_MSG_TAIL] = SPI_6358_MSG_TAIL,
466 [SPI_RX_TAIL] = SPI_6358_RX_TAIL,
467 [SPI_MSG_CTL] = SPI_6358_MSG_CTL,
468 [SPI_MSG_DATA] = SPI_6358_MSG_DATA,
469 [SPI_RX_DATA] = SPI_6358_RX_DATA,
470 [SPI_MSG_TYPE_SHIFT] = SPI_6358_MSG_TYPE_SHIFT,
471 [SPI_MSG_CTL_WIDTH] = SPI_6358_MSG_CTL_WIDTH,
472 [SPI_MSG_DATA_SIZE] = SPI_6358_MSG_DATA_SIZE,
475 static const struct platform_device_id bcm63xx_spi_dev_match[] = {
477 .name = "bcm6348-spi",
478 .driver_data = (unsigned long)bcm6348_spi_reg_offsets,
481 .name = "bcm6358-spi",
482 .driver_data = (unsigned long)bcm6358_spi_reg_offsets,
488 static const struct of_device_id bcm63xx_spi_of_match[] = {
489 { .compatible = "brcm,bcm6348-spi", .data = &bcm6348_spi_reg_offsets },
490 { .compatible = "brcm,bcm6358-spi", .data = &bcm6358_spi_reg_offsets },
494 static int bcm63xx_spi_probe(struct platform_device *pdev)
497 const unsigned long *bcm63xx_spireg;
498 struct device *dev = &pdev->dev;
500 struct spi_master *master;
502 struct bcm63xx_spi *bs;
504 u32 num_cs = BCM63XX_SPI_MAX_CS;
507 const struct of_device_id *match;
509 match = of_match_node(bcm63xx_spi_of_match, dev->of_node);
512 bcm63xx_spireg = match->data;
514 of_property_read_u32(dev->of_node, "num-cs", &num_cs);
515 if (num_cs > BCM63XX_SPI_MAX_CS) {
516 dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n",
518 num_cs = BCM63XX_SPI_MAX_CS;
522 } else if (pdev->id_entry->driver_data) {
523 const struct platform_device_id *match = pdev->id_entry;
525 bcm63xx_spireg = (const unsigned long *)match->driver_data;
526 bus_num = BCM63XX_SPI_BUS_NUM;
531 irq = platform_get_irq(pdev, 0);
533 dev_err(dev, "no irq: %d\n", irq);
537 clk = devm_clk_get(dev, "spi");
539 dev_err(dev, "no clock for device\n");
543 master = spi_alloc_master(dev, sizeof(*bs));
545 dev_err(dev, "out of memory\n");
549 bs = spi_master_get_devdata(master);
550 init_completion(&bs->done);
552 platform_set_drvdata(pdev, master);
555 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
556 bs->regs = devm_ioremap_resource(&pdev->dev, r);
557 if (IS_ERR(bs->regs)) {
558 ret = PTR_ERR(bs->regs);
564 bs->reg_offsets = bcm63xx_spireg;
565 bs->fifo_size = bs->reg_offsets[SPI_MSG_DATA_SIZE];
567 ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
570 dev_err(dev, "unable to request irq\n");
574 master->dev.of_node = dev->of_node;
575 master->bus_num = bus_num;
576 master->num_chipselect = num_cs;
577 master->transfer_one_message = bcm63xx_spi_transfer_one;
578 master->mode_bits = MODEBITS;
579 master->bits_per_word_mask = SPI_BPW_MASK(8);
580 master->max_transfer_size = bcm63xx_spi_max_length;
581 master->max_message_size = bcm63xx_spi_max_length;
582 master->auto_runtime_pm = true;
583 bs->msg_type_shift = bs->reg_offsets[SPI_MSG_TYPE_SHIFT];
584 bs->msg_ctl_width = bs->reg_offsets[SPI_MSG_CTL_WIDTH];
585 bs->tx_io = (u8 *)(bs->regs + bs->reg_offsets[SPI_MSG_DATA]);
586 bs->rx_io = (const u8 *)(bs->regs + bs->reg_offsets[SPI_RX_DATA]);
588 /* Initialize hardware */
589 ret = clk_prepare_enable(bs->clk);
593 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
595 /* register and we are done */
596 ret = devm_spi_register_master(dev, master);
598 dev_err(dev, "spi register failed\n");
599 goto out_clk_disable;
602 dev_info(dev, "at %pr (irq %d, FIFOs size %d)\n",
603 r, irq, bs->fifo_size);
608 clk_disable_unprepare(clk);
610 spi_master_put(master);
614 static int bcm63xx_spi_remove(struct platform_device *pdev)
616 struct spi_master *master = platform_get_drvdata(pdev);
617 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
619 /* reset spi block */
620 bcm_spi_writeb(bs, 0, SPI_INT_MASK);
623 clk_disable_unprepare(bs->clk);
628 #ifdef CONFIG_PM_SLEEP
629 static int bcm63xx_spi_suspend(struct device *dev)
631 struct spi_master *master = dev_get_drvdata(dev);
632 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
634 spi_master_suspend(master);
636 clk_disable_unprepare(bs->clk);
641 static int bcm63xx_spi_resume(struct device *dev)
643 struct spi_master *master = dev_get_drvdata(dev);
644 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
647 ret = clk_prepare_enable(bs->clk);
651 spi_master_resume(master);
657 static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
658 SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume)
661 static struct platform_driver bcm63xx_spi_driver = {
663 .name = "bcm63xx-spi",
664 .pm = &bcm63xx_spi_pm_ops,
665 .of_match_table = bcm63xx_spi_of_match,
667 .id_table = bcm63xx_spi_dev_match,
668 .probe = bcm63xx_spi_probe,
669 .remove = bcm63xx_spi_remove,
672 module_platform_driver(bcm63xx_spi_driver);
674 MODULE_ALIAS("platform:bcm63xx_spi");
677 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
678 MODULE_LICENSE("GPL");