1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
5 #include <linux/interrupt.h>
7 #include <linux/log2.h>
8 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/pm_runtime.h>
12 #include <linux/qcom-geni-se.h>
13 #include <linux/spi/spi.h>
14 #include <linux/spinlock.h>
16 /* SPI SE specific registers and respective register fields */
17 #define SE_SPI_CPHA 0x224
20 #define SE_SPI_LOOPBACK 0x22c
21 #define LOOPBACK_ENABLE 0x1
22 #define NORMAL_MODE 0x0
23 #define LOOPBACK_MSK GENMASK(1, 0)
25 #define SE_SPI_CPOL 0x230
28 #define SE_SPI_DEMUX_OUTPUT_INV 0x24c
29 #define CS_DEMUX_OUTPUT_INV_MSK GENMASK(3, 0)
31 #define SE_SPI_DEMUX_SEL 0x250
32 #define CS_DEMUX_OUTPUT_SEL GENMASK(3, 0)
34 #define SE_SPI_TRANS_CFG 0x25c
35 #define CS_TOGGLE BIT(0)
37 #define SE_SPI_WORD_LEN 0x268
38 #define WORD_LEN_MSK GENMASK(9, 0)
39 #define MIN_WORD_LEN 4
41 #define SE_SPI_TX_TRANS_LEN 0x26c
42 #define SE_SPI_RX_TRANS_LEN 0x270
43 #define TRANS_LEN_MSK GENMASK(23, 0)
45 #define SE_SPI_PRE_POST_CMD_DLY 0x274
47 #define SE_SPI_DELAY_COUNTERS 0x278
48 #define SPI_INTER_WORDS_DELAY_MSK GENMASK(9, 0)
49 #define SPI_CS_CLK_DELAY_MSK GENMASK(19, 10)
50 #define SPI_CS_CLK_DELAY_SHFT 10
52 /* M_CMD OP codes for SPI */
55 #define SPI_FULL_DUPLEX 3
57 #define SPI_CS_ASSERT 8
58 #define SPI_CS_DEASSERT 9
59 #define SPI_SCK_ONLY 10
60 /* M_CMD params for SPI */
61 #define SPI_PRE_CMD_DELAY BIT(0)
62 #define TIMESTAMP_BEFORE BIT(1)
63 #define FRAGMENTATION BIT(2)
64 #define TIMESTAMP_AFTER BIT(3)
65 #define POST_CMD_DELAY BIT(4)
67 enum spi_m_cmd_opcode {
74 struct spi_geni_master {
80 unsigned long cur_speed_hz;
81 unsigned int cur_bits_per_word;
82 unsigned int tx_rem_bytes;
83 unsigned int rx_rem_bytes;
84 const struct spi_transfer *cur_xfer;
85 struct completion xfer_done;
86 unsigned int oversampling;
88 enum spi_m_cmd_opcode cur_mcmd;
92 static int get_spi_clk_cfg(unsigned int speed_hz,
93 struct spi_geni_master *mas,
94 unsigned int *clk_idx,
95 unsigned int *clk_div)
97 unsigned long sclk_freq;
98 unsigned int actual_hz;
99 struct geni_se *se = &mas->se;
102 ret = geni_se_clk_freq_match(&mas->se,
103 speed_hz * mas->oversampling,
104 clk_idx, &sclk_freq, false);
106 dev_err(mas->dev, "Failed(%d) to find src clk for %dHz\n",
111 *clk_div = DIV_ROUND_UP(sclk_freq, mas->oversampling * speed_hz);
112 actual_hz = sclk_freq / (mas->oversampling * *clk_div);
114 dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
115 actual_hz, sclk_freq, *clk_idx, *clk_div);
116 ret = clk_set_rate(se->clk, sclk_freq);
118 dev_err(mas->dev, "clk_set_rate failed %d\n", ret);
122 static void handle_fifo_timeout(struct spi_master *spi,
123 struct spi_message *msg)
125 struct spi_geni_master *mas = spi_master_get_devdata(spi);
126 unsigned long time_left, flags;
127 struct geni_se *se = &mas->se;
129 spin_lock_irqsave(&mas->lock, flags);
130 reinit_completion(&mas->xfer_done);
131 mas->cur_mcmd = CMD_CANCEL;
132 geni_se_cancel_m_cmd(se);
133 writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
134 spin_unlock_irqrestore(&mas->lock, flags);
135 time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
139 spin_lock_irqsave(&mas->lock, flags);
140 reinit_completion(&mas->xfer_done);
141 geni_se_abort_m_cmd(se);
142 spin_unlock_irqrestore(&mas->lock, flags);
143 time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
145 dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
148 static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
150 struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
151 struct spi_master *spi = dev_get_drvdata(mas->dev);
152 struct geni_se *se = &mas->se;
153 unsigned long time_left;
155 reinit_completion(&mas->xfer_done);
156 pm_runtime_get_sync(mas->dev);
157 if (!(slv->mode & SPI_CS_HIGH))
158 set_flag = !set_flag;
160 mas->cur_mcmd = CMD_CS;
162 geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
164 geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
166 time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
168 handle_fifo_timeout(spi, NULL);
170 pm_runtime_put(mas->dev);
173 static void spi_setup_word_len(struct spi_geni_master *mas, u16 mode,
174 unsigned int bits_per_word)
176 unsigned int pack_words;
177 bool msb_first = (mode & SPI_LSB_FIRST) ? false : true;
178 struct geni_se *se = &mas->se;
181 word_len = readl(se->base + SE_SPI_WORD_LEN);
184 * If bits_per_word isn't a byte aligned value, set the packing to be
185 * 1 SPI word per FIFO word.
187 if (!(mas->fifo_width_bits % bits_per_word))
188 pack_words = mas->fifo_width_bits / bits_per_word;
191 word_len &= ~WORD_LEN_MSK;
192 word_len |= ((bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK);
193 geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first,
195 writel(word_len, se->base + SE_SPI_WORD_LEN);
198 static int setup_fifo_params(struct spi_device *spi_slv,
199 struct spi_master *spi)
201 struct spi_geni_master *mas = spi_master_get_devdata(spi);
202 struct geni_se *se = &mas->se;
203 u32 loopback_cfg, cpol, cpha, demux_output_inv;
204 u32 demux_sel, clk_sel, m_clk_cfg, idx, div;
207 loopback_cfg = readl(se->base + SE_SPI_LOOPBACK);
208 cpol = readl(se->base + SE_SPI_CPOL);
209 cpha = readl(se->base + SE_SPI_CPHA);
210 demux_output_inv = 0;
211 loopback_cfg &= ~LOOPBACK_MSK;
215 if (spi_slv->mode & SPI_LOOP)
216 loopback_cfg |= LOOPBACK_ENABLE;
218 if (spi_slv->mode & SPI_CPOL)
221 if (spi_slv->mode & SPI_CPHA)
224 if (spi_slv->mode & SPI_CS_HIGH)
225 demux_output_inv = BIT(spi_slv->chip_select);
227 demux_sel = spi_slv->chip_select;
228 mas->cur_speed_hz = spi_slv->max_speed_hz;
229 mas->cur_bits_per_word = spi_slv->bits_per_word;
231 ret = get_spi_clk_cfg(mas->cur_speed_hz, mas, &idx, &div);
233 dev_err(mas->dev, "Err setting clks ret(%d) for %ld\n",
234 ret, mas->cur_speed_hz);
238 clk_sel = idx & CLK_SEL_MSK;
239 m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
240 spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
241 writel(loopback_cfg, se->base + SE_SPI_LOOPBACK);
242 writel(demux_sel, se->base + SE_SPI_DEMUX_SEL);
243 writel(cpha, se->base + SE_SPI_CPHA);
244 writel(cpol, se->base + SE_SPI_CPOL);
245 writel(demux_output_inv, se->base + SE_SPI_DEMUX_OUTPUT_INV);
246 writel(clk_sel, se->base + SE_GENI_CLK_SEL);
247 writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
251 static int spi_geni_prepare_message(struct spi_master *spi,
252 struct spi_message *spi_msg)
255 struct spi_geni_master *mas = spi_master_get_devdata(spi);
256 struct geni_se *se = &mas->se;
258 geni_se_select_mode(se, GENI_SE_FIFO);
259 ret = setup_fifo_params(spi_msg->spi, spi);
261 dev_err(mas->dev, "Couldn't select mode %d\n", ret);
265 static int spi_geni_init(struct spi_geni_master *mas)
267 struct geni_se *se = &mas->se;
268 unsigned int proto, major, minor, ver;
270 pm_runtime_get_sync(mas->dev);
272 proto = geni_se_read_proto(se);
273 if (proto != GENI_SE_SPI) {
274 dev_err(mas->dev, "Invalid proto %d\n", proto);
275 pm_runtime_put(mas->dev);
278 mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se);
280 /* Width of Tx and Rx FIFO is same */
281 mas->fifo_width_bits = geni_se_get_tx_fifo_width(se);
284 * Hardware programming guide suggests to configure
285 * RX FIFO RFR level to fifo_depth-2.
287 geni_se_init(se, 0x0, mas->tx_fifo_depth - 2);
288 /* Transmit an entire FIFO worth of data per IRQ */
290 ver = geni_se_get_qup_hw_version(se);
291 major = GENI_SE_VERSION_MAJOR(ver);
292 minor = GENI_SE_VERSION_MINOR(ver);
294 if (major == 1 && minor == 0)
295 mas->oversampling = 2;
297 mas->oversampling = 1;
299 pm_runtime_put(mas->dev);
303 static void setup_fifo_xfer(struct spi_transfer *xfer,
304 struct spi_geni_master *mas,
305 u16 mode, struct spi_master *spi)
309 struct geni_se *se = &mas->se;
311 spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
312 if (xfer->bits_per_word != mas->cur_bits_per_word) {
313 spi_setup_word_len(mas, mode, xfer->bits_per_word);
314 mas->cur_bits_per_word = xfer->bits_per_word;
317 /* Speed and bits per word can be overridden per transfer */
318 if (xfer->speed_hz != mas->cur_speed_hz) {
320 u32 clk_sel, m_clk_cfg;
321 unsigned int idx, div;
323 ret = get_spi_clk_cfg(xfer->speed_hz, mas, &idx, &div);
325 dev_err(mas->dev, "Err setting clks:%d\n", ret);
329 * SPI core clock gets configured with the requested frequency
330 * or the frequency closer to the requested frequency.
331 * For that reason requested frequency is stored in the
332 * cur_speed_hz and referred in the consecutive transfer instead
333 * of calling clk_get_rate() API.
335 mas->cur_speed_hz = xfer->speed_hz;
336 clk_sel = idx & CLK_SEL_MSK;
337 m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
338 writel(clk_sel, se->base + SE_GENI_CLK_SEL);
339 writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
342 mas->tx_rem_bytes = 0;
343 mas->rx_rem_bytes = 0;
344 if (xfer->tx_buf && xfer->rx_buf)
345 m_cmd = SPI_FULL_DUPLEX;
346 else if (xfer->tx_buf)
348 else if (xfer->rx_buf)
351 spi_tx_cfg &= ~CS_TOGGLE;
353 if (!(mas->cur_bits_per_word % MIN_WORD_LEN))
354 len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word;
356 len = xfer->len / (mas->cur_bits_per_word / BITS_PER_BYTE + 1);
357 len &= TRANS_LEN_MSK;
359 mas->cur_xfer = xfer;
360 if (m_cmd & SPI_TX_ONLY) {
361 mas->tx_rem_bytes = xfer->len;
362 writel(len, se->base + SE_SPI_TX_TRANS_LEN);
365 if (m_cmd & SPI_RX_ONLY) {
366 writel(len, se->base + SE_SPI_RX_TRANS_LEN);
367 mas->rx_rem_bytes = xfer->len;
369 writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
370 mas->cur_mcmd = CMD_XFER;
371 geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
374 * TX_WATERMARK_REG should be set after SPI configuration and
375 * setting up GENI SE engine, as driver starts data transfer
376 * for the watermark interrupt.
378 if (m_cmd & SPI_TX_ONLY)
379 writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
382 static int spi_geni_transfer_one(struct spi_master *spi,
383 struct spi_device *slv,
384 struct spi_transfer *xfer)
386 struct spi_geni_master *mas = spi_master_get_devdata(spi);
388 /* Terminate and return success for 0 byte length transfer */
392 setup_fifo_xfer(xfer, mas, slv->mode, spi);
396 static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas)
399 * Calculate how many bytes we'll put in each FIFO word. If the
400 * transfer words don't pack cleanly into a FIFO word we'll just put
401 * one transfer word in each FIFO word. If they do pack we'll pack 'em.
403 if (mas->fifo_width_bits % mas->cur_bits_per_word)
404 return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word,
407 return mas->fifo_width_bits / BITS_PER_BYTE;
410 static void geni_spi_handle_tx(struct spi_geni_master *mas)
412 struct geni_se *se = &mas->se;
413 unsigned int max_bytes;
415 unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
418 max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word;
419 if (mas->tx_rem_bytes < max_bytes)
420 max_bytes = mas->tx_rem_bytes;
422 tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes;
423 while (i < max_bytes) {
425 unsigned int bytes_to_write;
427 u8 *fifo_byte = (u8 *)&fifo_word;
429 bytes_to_write = min(bytes_per_fifo_word, max_bytes - i);
430 for (j = 0; j < bytes_to_write; j++)
431 fifo_byte[j] = tx_buf[i++];
432 iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1);
434 mas->tx_rem_bytes -= max_bytes;
435 if (!mas->tx_rem_bytes)
436 writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
439 static void geni_spi_handle_rx(struct spi_geni_master *mas)
441 struct geni_se *se = &mas->se;
443 unsigned int rx_bytes;
444 unsigned int rx_last_byte_valid;
446 unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
449 rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS);
450 rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word;
451 if (rx_fifo_status & RX_LAST) {
452 rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK;
453 rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT;
454 if (rx_last_byte_valid && rx_last_byte_valid < 4)
455 rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid;
457 if (mas->rx_rem_bytes < rx_bytes)
458 rx_bytes = mas->rx_rem_bytes;
460 rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes;
461 while (i < rx_bytes) {
463 u8 *fifo_byte = (u8 *)&fifo_word;
464 unsigned int bytes_to_read;
467 bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i);
468 ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1);
469 for (j = 0; j < bytes_to_read; j++)
470 rx_buf[i++] = fifo_byte[j];
472 mas->rx_rem_bytes -= rx_bytes;
475 static irqreturn_t geni_spi_isr(int irq, void *data)
477 struct spi_master *spi = data;
478 struct spi_geni_master *mas = spi_master_get_devdata(spi);
479 struct geni_se *se = &mas->se;
483 if (mas->cur_mcmd == CMD_NONE)
486 spin_lock_irqsave(&mas->lock, flags);
487 m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
489 if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
490 geni_spi_handle_rx(mas);
492 if (m_irq & M_TX_FIFO_WATERMARK_EN)
493 geni_spi_handle_tx(mas);
495 if (m_irq & M_CMD_DONE_EN) {
496 if (mas->cur_mcmd == CMD_XFER)
497 spi_finalize_current_transfer(spi);
498 else if (mas->cur_mcmd == CMD_CS)
499 complete(&mas->xfer_done);
500 mas->cur_mcmd = CMD_NONE;
502 * If this happens, then a CMD_DONE came before all the Tx
503 * buffer bytes were sent out. This is unusual, log this
504 * condition and disable the WM interrupt to prevent the
505 * system from stalling due an interrupt storm.
506 * If this happens when all Rx bytes haven't been received, log
508 * The only known time this can happen is if bits_per_word != 8
509 * and some registers that expect xfer lengths in num spi_words
510 * weren't written correctly.
512 if (mas->tx_rem_bytes) {
513 writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
514 dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
515 mas->tx_rem_bytes, mas->cur_bits_per_word);
517 if (mas->rx_rem_bytes)
518 dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
519 mas->rx_rem_bytes, mas->cur_bits_per_word);
522 if ((m_irq & M_CMD_CANCEL_EN) || (m_irq & M_CMD_ABORT_EN)) {
523 mas->cur_mcmd = CMD_NONE;
524 complete(&mas->xfer_done);
527 writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
528 spin_unlock_irqrestore(&mas->lock, flags);
532 static int spi_geni_probe(struct platform_device *pdev)
535 struct spi_master *spi;
536 struct spi_geni_master *mas;
540 irq = platform_get_irq(pdev, 0);
544 base = devm_platform_ioremap_resource(pdev, 0);
546 return PTR_ERR(base);
548 clk = devm_clk_get(&pdev->dev, "se");
550 dev_err(&pdev->dev, "Err getting SE Core clk %ld\n",
555 spi = spi_alloc_master(&pdev->dev, sizeof(*mas));
559 platform_set_drvdata(pdev, spi);
560 mas = spi_master_get_devdata(spi);
562 mas->dev = &pdev->dev;
563 mas->se.dev = &pdev->dev;
564 mas->se.wrapper = dev_get_drvdata(pdev->dev.parent);
569 spi->dev.of_node = pdev->dev.of_node;
570 spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
571 spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
572 spi->num_chipselect = 4;
573 spi->max_speed_hz = 50000000;
574 spi->prepare_message = spi_geni_prepare_message;
575 spi->transfer_one = spi_geni_transfer_one;
576 spi->auto_runtime_pm = true;
577 spi->handle_err = handle_fifo_timeout;
578 spi->set_cs = spi_geni_set_cs;
580 init_completion(&mas->xfer_done);
581 spin_lock_init(&mas->lock);
582 pm_runtime_enable(&pdev->dev);
584 ret = spi_geni_init(mas);
586 goto spi_geni_probe_runtime_disable;
588 ret = request_irq(mas->irq, geni_spi_isr,
589 IRQF_TRIGGER_HIGH, "spi_geni", spi);
591 goto spi_geni_probe_runtime_disable;
593 ret = spi_register_master(spi);
595 goto spi_geni_probe_free_irq;
598 spi_geni_probe_free_irq:
599 free_irq(mas->irq, spi);
600 spi_geni_probe_runtime_disable:
601 pm_runtime_disable(&pdev->dev);
606 static int spi_geni_remove(struct platform_device *pdev)
608 struct spi_master *spi = platform_get_drvdata(pdev);
609 struct spi_geni_master *mas = spi_master_get_devdata(spi);
611 /* Unregister _before_ disabling pm_runtime() so we stop transfers */
612 spi_unregister_master(spi);
614 free_irq(mas->irq, spi);
615 pm_runtime_disable(&pdev->dev);
619 static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
621 struct spi_master *spi = dev_get_drvdata(dev);
622 struct spi_geni_master *mas = spi_master_get_devdata(spi);
624 return geni_se_resources_off(&mas->se);
627 static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
629 struct spi_master *spi = dev_get_drvdata(dev);
630 struct spi_geni_master *mas = spi_master_get_devdata(spi);
632 return geni_se_resources_on(&mas->se);
635 static int __maybe_unused spi_geni_suspend(struct device *dev)
637 struct spi_master *spi = dev_get_drvdata(dev);
640 ret = spi_master_suspend(spi);
644 ret = pm_runtime_force_suspend(dev);
646 spi_master_resume(spi);
651 static int __maybe_unused spi_geni_resume(struct device *dev)
653 struct spi_master *spi = dev_get_drvdata(dev);
656 ret = pm_runtime_force_resume(dev);
660 ret = spi_master_resume(spi);
662 pm_runtime_force_suspend(dev);
667 static const struct dev_pm_ops spi_geni_pm_ops = {
668 SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend,
669 spi_geni_runtime_resume, NULL)
670 SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, spi_geni_resume)
673 static const struct of_device_id spi_geni_dt_match[] = {
674 { .compatible = "qcom,geni-spi" },
677 MODULE_DEVICE_TABLE(of, spi_geni_dt_match);
679 static struct platform_driver spi_geni_driver = {
680 .probe = spi_geni_probe,
681 .remove = spi_geni_remove,
684 .pm = &spi_geni_pm_ops,
685 .of_match_table = spi_geni_dt_match,
688 module_platform_driver(spi_geni_driver);
690 MODULE_DESCRIPTION("SPI driver for GENI based QUP cores");
691 MODULE_LICENSE("GPL v2");