1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
3
4#include <linux/clk.h>
5#include <linux/dmapool.h>
6#include <linux/dma-mapping.h>
7#include <linux/interconnect.h>
8#include <linux/interrupt.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/pinctrl/consumer.h>
14#include <linux/pm_runtime.h>
15#include <linux/pm_opp.h>
16#include <linux/spi/spi.h>
17#include <linux/spi/spi-mem.h>
18
19
20#define QSPI_NUM_CS		2
21#define QSPI_BYTES_PER_WORD	4
22
23#define MSTR_CONFIG		0x0000
24#define FULL_CYCLE_MODE		BIT(3)
25#define FB_CLK_EN		BIT(4)
26#define PIN_HOLDN		BIT(6)
27#define PIN_WPN			BIT(7)
28#define DMA_ENABLE		BIT(8)
29#define BIG_ENDIAN_MODE		BIT(9)
30#define SPI_MODE_MSK		0xc00
31#define SPI_MODE_SHFT		10
32#define CHIP_SELECT_NUM		BIT(12)
33#define SBL_EN			BIT(13)
34#define LPA_BASE_MSK		0x3c000
35#define LPA_BASE_SHFT		14
36#define TX_DATA_DELAY_MSK	0xc0000
37#define TX_DATA_DELAY_SHFT	18
38#define TX_CLK_DELAY_MSK	0x300000
39#define TX_CLK_DELAY_SHFT	20
40#define TX_CS_N_DELAY_MSK	0xc00000
41#define TX_CS_N_DELAY_SHFT	22
42#define TX_DATA_OE_DELAY_MSK	0x3000000
43#define TX_DATA_OE_DELAY_SHFT	24
44
45#define AHB_MASTER_CFG				0x0004
46#define HMEM_TYPE_START_MID_TRANS_MSK		0x7
47#define HMEM_TYPE_START_MID_TRANS_SHFT		0
48#define HMEM_TYPE_LAST_TRANS_MSK		0x38
49#define HMEM_TYPE_LAST_TRANS_SHFT		3
50#define USE_HMEMTYPE_LAST_ON_DESC_OR_CHAIN_MSK	0xc0
51#define USE_HMEMTYPE_LAST_ON_DESC_OR_CHAIN_SHFT	6
52#define HMEMTYPE_READ_TRANS_MSK			0x700
53#define HMEMTYPE_READ_TRANS_SHFT		8
54#define HSHARED					BIT(11)
55#define HINNERSHARED				BIT(12)
56
57#define MSTR_INT_EN		0x000C
58#define MSTR_INT_STATUS		0x0010
59#define RESP_FIFO_UNDERRUN	BIT(0)
60#define RESP_FIFO_NOT_EMPTY	BIT(1)
61#define RESP_FIFO_RDY		BIT(2)
62#define HRESP_FROM_NOC_ERR	BIT(3)
63#define WR_FIFO_EMPTY		BIT(9)
64#define WR_FIFO_FULL		BIT(10)
65#define WR_FIFO_OVERRUN		BIT(11)
66#define TRANSACTION_DONE	BIT(16)
67#define DMA_CHAIN_DONE		BIT(31)
68#define QSPI_ERR_IRQS		(RESP_FIFO_UNDERRUN | HRESP_FROM_NOC_ERR | \
69				 WR_FIFO_OVERRUN)
70#define QSPI_ALL_IRQS		(QSPI_ERR_IRQS | RESP_FIFO_RDY | \
71				 WR_FIFO_EMPTY | WR_FIFO_FULL | \
72				 TRANSACTION_DONE | DMA_CHAIN_DONE)
73
74#define PIO_XFER_CTRL		0x0014
75#define REQUEST_COUNT_MSK	0xffff
76
77#define PIO_XFER_CFG		0x0018
78#define TRANSFER_DIRECTION	BIT(0)
79#define MULTI_IO_MODE_MSK	0xe
80#define MULTI_IO_MODE_SHFT	1
81#define TRANSFER_FRAGMENT	BIT(8)
82#define SDR_1BIT		1
83#define SDR_2BIT		2
84#define SDR_4BIT		3
85#define DDR_1BIT		5
86#define DDR_2BIT		6
87#define DDR_4BIT		7
88#define DMA_DESC_SINGLE_SPI	1
89#define DMA_DESC_DUAL_SPI	2
90#define DMA_DESC_QUAD_SPI	3
91
92#define PIO_XFER_STATUS		0x001c
93#define WR_FIFO_BYTES_MSK	0xffff0000
94#define WR_FIFO_BYTES_SHFT	16
95
96#define PIO_DATAOUT_1B		0x0020
97#define PIO_DATAOUT_4B		0x0024
98
99#define RD_FIFO_CFG		0x0028
100#define CONTINUOUS_MODE		BIT(0)
101
102#define RD_FIFO_STATUS	0x002c
103#define FIFO_EMPTY	BIT(11)
104#define WR_CNTS_MSK	0x7f0
105#define WR_CNTS_SHFT	4
106#define RDY_64BYTE	BIT(3)
107#define RDY_32BYTE	BIT(2)
108#define RDY_16BYTE	BIT(1)
109#define FIFO_RDY	BIT(0)
110
111#define RD_FIFO_RESET		0x0030
112#define RESET_FIFO		BIT(0)
113
114#define NEXT_DMA_DESC_ADDR	0x0040
115#define CURRENT_DMA_DESC_ADDR	0x0044
116#define CURRENT_MEM_ADDR	0x0048
117
118#define CUR_MEM_ADDR		0x0048
119#define HW_VERSION		0x004c
120#define RD_FIFO			0x0050
121#define SAMPLING_CLK_CFG	0x0090
122#define SAMPLING_CLK_STATUS	0x0094
123
124#define QSPI_ALIGN_REQ	32
125
126enum qspi_dir {
127	QSPI_READ,
128	QSPI_WRITE,
129};
130
131struct qspi_cmd_desc {
132	u32 data_address;
133	u32 next_descriptor;
134	u32 direction:1;
135	u32 multi_io_mode:3;
136	u32 reserved1:4;
137	u32 fragment:1;
138	u32 reserved2:7;
139	u32 length:16;
140};
141
142struct qspi_xfer {
143	union {
144		const void *tx_buf;
145		void *rx_buf;
146	};
147	unsigned int rem_bytes;
148	unsigned int buswidth;
149	enum qspi_dir dir;
150	bool is_last;
151};
152
153enum qspi_clocks {
154	QSPI_CLK_CORE,
155	QSPI_CLK_IFACE,
156	QSPI_NUM_CLKS
157};
158
159/*
160 * Number of entries in sgt returned from spi framework that-
161 * will be supported. Can be modified as required.
162 * In practice, given max_dma_len is 64KB, the number of
163 * entries is not expected to exceed 1.
164 */
165#define QSPI_MAX_SG 5
166
167struct qcom_qspi {
168	void __iomem *base;
169	struct device *dev;
170	struct clk_bulk_data *clks;
171	struct qspi_xfer xfer;
172	struct dma_pool *dma_cmd_pool;
173	dma_addr_t dma_cmd_desc[QSPI_MAX_SG];
174	void *virt_cmd_desc[QSPI_MAX_SG];
175	unsigned int n_cmd_desc;
176	struct icc_path *icc_path_cpu_to_qspi;
177	unsigned long last_speed;
178	/* Lock to protect data accessed by IRQs */
179	spinlock_t lock;
180};
181
182static u32 qspi_buswidth_to_iomode(struct qcom_qspi *ctrl,
183				   unsigned int buswidth)
184{
185	switch (buswidth) {
186	case 1:
187		return SDR_1BIT;
188	case 2:
189		return SDR_2BIT;
190	case 4:
191		return SDR_4BIT;
192	default:
193		dev_warn_once(ctrl->dev,
194				"Unexpected bus width: %u\n", buswidth);
195		return SDR_1BIT;
196	}
197}
198
199static void qcom_qspi_pio_xfer_cfg(struct qcom_qspi *ctrl)
200{
201	u32 pio_xfer_cfg;
202	u32 iomode;
203	const struct qspi_xfer *xfer;
204
205	xfer = &ctrl->xfer;
206	pio_xfer_cfg = readl(ctrl->base + PIO_XFER_CFG);
207	pio_xfer_cfg &= ~TRANSFER_DIRECTION;
208	pio_xfer_cfg |= xfer->dir;
209	if (xfer->is_last)
210		pio_xfer_cfg &= ~TRANSFER_FRAGMENT;
211	else
212		pio_xfer_cfg |= TRANSFER_FRAGMENT;
213	pio_xfer_cfg &= ~MULTI_IO_MODE_MSK;
214	iomode = qspi_buswidth_to_iomode(ctrl, xfer->buswidth);
215	pio_xfer_cfg |= iomode << MULTI_IO_MODE_SHFT;
216
217	writel(pio_xfer_cfg, ctrl->base + PIO_XFER_CFG);
218}
219
220static void qcom_qspi_pio_xfer_ctrl(struct qcom_qspi *ctrl)
221{
222	u32 pio_xfer_ctrl;
223
224	pio_xfer_ctrl = readl(ctrl->base + PIO_XFER_CTRL);
225	pio_xfer_ctrl &= ~REQUEST_COUNT_MSK;
226	pio_xfer_ctrl |= ctrl->xfer.rem_bytes;
227	writel(pio_xfer_ctrl, ctrl->base + PIO_XFER_CTRL);
228}
229
230static void qcom_qspi_pio_xfer(struct qcom_qspi *ctrl)
231{
232	u32 ints;
233
234	qcom_qspi_pio_xfer_cfg(ctrl);
235
236	/* Ack any previous interrupts that might be hanging around */
237	writel(QSPI_ALL_IRQS, ctrl->base + MSTR_INT_STATUS);
238
239	/* Setup new interrupts */
240	if (ctrl->xfer.dir == QSPI_WRITE)
241		ints = QSPI_ERR_IRQS | WR_FIFO_EMPTY;
242	else
243		ints = QSPI_ERR_IRQS | RESP_FIFO_RDY;
244	writel(ints, ctrl->base + MSTR_INT_EN);
245
246	/* Kick off the transfer */
247	qcom_qspi_pio_xfer_ctrl(ctrl);
248}
249
250static void qcom_qspi_handle_err(struct spi_controller *host,
251				 struct spi_message *msg)
252{
253	u32 int_status;
254	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
255	unsigned long flags;
256	int i;
257
258	spin_lock_irqsave(&ctrl->lock, flags);
259	writel(0, ctrl->base + MSTR_INT_EN);
260	int_status = readl(ctrl->base + MSTR_INT_STATUS);
261	writel(int_status, ctrl->base + MSTR_INT_STATUS);
262	ctrl->xfer.rem_bytes = 0;
263
264	/* free cmd descriptors if they are around (DMA mode) */
265	for (i = 0; i < ctrl->n_cmd_desc; i++)
266		dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i],
267				  ctrl->dma_cmd_desc[i]);
268	ctrl->n_cmd_desc = 0;
269	spin_unlock_irqrestore(&ctrl->lock, flags);
270}
271
272static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
273{
274	int ret;
275	unsigned int avg_bw_cpu;
276
277	if (speed_hz == ctrl->last_speed)
278		return 0;
279
280	/* In regular operation (SBL_EN=1) core must be 4x transfer clock */
281	ret = dev_pm_opp_set_rate(ctrl->dev, speed_hz * 4);
282	if (ret) {
283		dev_err(ctrl->dev, "Failed to set core clk %d\n", ret);
284		return ret;
285	}
286
287	/*
288	 * Set BW quota for CPU.
289	 * We don't have explicit peak requirement so keep it equal to avg_bw.
290	 */
291	avg_bw_cpu = Bps_to_icc(speed_hz);
292	ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, avg_bw_cpu, avg_bw_cpu);
293	if (ret) {
294		dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu: %d\n",
295			__func__, ret);
296		return ret;
297	}
298
299	ctrl->last_speed = speed_hz;
300
301	return 0;
302}
303
304static int qcom_qspi_alloc_desc(struct qcom_qspi *ctrl, dma_addr_t dma_ptr,
305			uint32_t n_bytes)
306{
307	struct qspi_cmd_desc *virt_cmd_desc, *prev;
308	dma_addr_t dma_cmd_desc;
309
310	/* allocate for dma cmd descriptor */
311	virt_cmd_desc = dma_pool_alloc(ctrl->dma_cmd_pool, GFP_ATOMIC | __GFP_ZERO, &dma_cmd_desc);
312	if (!virt_cmd_desc) {
313		dev_warn_once(ctrl->dev, "Couldn't find memory for descriptor\n");
314		return -EAGAIN;
315	}
316
317	ctrl->virt_cmd_desc[ctrl->n_cmd_desc] = virt_cmd_desc;
318	ctrl->dma_cmd_desc[ctrl->n_cmd_desc] = dma_cmd_desc;
319	ctrl->n_cmd_desc++;
320
321	/* setup cmd descriptor */
322	virt_cmd_desc->data_address = dma_ptr;
323	virt_cmd_desc->direction = ctrl->xfer.dir;
324	virt_cmd_desc->multi_io_mode = qspi_buswidth_to_iomode(ctrl, ctrl->xfer.buswidth);
325	virt_cmd_desc->fragment = !ctrl->xfer.is_last;
326	virt_cmd_desc->length = n_bytes;
327
328	/* update previous descriptor */
329	if (ctrl->n_cmd_desc >= 2) {
330		prev = (ctrl->virt_cmd_desc)[ctrl->n_cmd_desc - 2];
331		prev->next_descriptor = dma_cmd_desc;
332		prev->fragment = 1;
333	}
334
335	return 0;
336}
337
338static int qcom_qspi_setup_dma_desc(struct qcom_qspi *ctrl,
339				struct spi_transfer *xfer)
340{
341	int ret;
342	struct sg_table *sgt;
343	dma_addr_t dma_ptr_sg;
344	unsigned int dma_len_sg;
345	int i;
346
347	if (ctrl->n_cmd_desc) {
348		dev_err(ctrl->dev, "Remnant dma buffers n_cmd_desc-%d\n", ctrl->n_cmd_desc);
349		return -EIO;
350	}
351
352	sgt = (ctrl->xfer.dir == QSPI_READ) ? &xfer->rx_sg : &xfer->tx_sg;
353	if (!sgt->nents || sgt->nents > QSPI_MAX_SG) {
354		dev_warn_once(ctrl->dev, "Cannot handle %d entries in scatter list\n", sgt->nents);
355		return -EAGAIN;
356	}
357
358	for (i = 0; i < sgt->nents; i++) {
359		dma_ptr_sg = sg_dma_address(sgt->sgl + i);
360		dma_len_sg = sg_dma_len(sgt->sgl + i);
361		if (!IS_ALIGNED(dma_ptr_sg, QSPI_ALIGN_REQ)) {
362			dev_warn_once(ctrl->dev, "dma_address not aligned to %d\n", QSPI_ALIGN_REQ);
363			return -EAGAIN;
364		}
365		/*
366		 * When reading with DMA the controller writes to memory 1 word
367		 * at a time. If the length isn't a multiple of 4 bytes then
368		 * the controller can clobber the things later in memory.
369		 * Fallback to PIO to be safe.
370		 */
371		if (ctrl->xfer.dir == QSPI_READ && (dma_len_sg & 0x03)) {
372			dev_warn_once(ctrl->dev, "fallback to PIO for read of size %#010x\n",
373				      dma_len_sg);
374			return -EAGAIN;
375		}
376	}
377
378	for (i = 0; i < sgt->nents; i++) {
379		dma_ptr_sg = sg_dma_address(sgt->sgl + i);
380		dma_len_sg = sg_dma_len(sgt->sgl + i);
381
382		ret = qcom_qspi_alloc_desc(ctrl, dma_ptr_sg, dma_len_sg);
383		if (ret)
384			goto cleanup;
385	}
386	return 0;
387
388cleanup:
389	for (i = 0; i < ctrl->n_cmd_desc; i++)
390		dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i],
391				  ctrl->dma_cmd_desc[i]);
392	ctrl->n_cmd_desc = 0;
393	return ret;
394}
395
396static void qcom_qspi_dma_xfer(struct qcom_qspi *ctrl)
397{
398	/* Setup new interrupts */
399	writel(DMA_CHAIN_DONE, ctrl->base + MSTR_INT_EN);
400
401	/* kick off transfer */
402	writel((u32)((ctrl->dma_cmd_desc)[0]), ctrl->base + NEXT_DMA_DESC_ADDR);
403}
404
405/* Switch to DMA if transfer length exceeds this */
406#define QSPI_MAX_BYTES_FIFO 64
407
408static bool qcom_qspi_can_dma(struct spi_controller *ctlr,
409			 struct spi_device *slv, struct spi_transfer *xfer)
410{
411	return xfer->len > QSPI_MAX_BYTES_FIFO;
412}
413
414static int qcom_qspi_transfer_one(struct spi_controller *host,
415				  struct spi_device *slv,
416				  struct spi_transfer *xfer)
417{
418	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
419	int ret;
420	unsigned long speed_hz;
421	unsigned long flags;
422	u32 mstr_cfg;
423
424	speed_hz = slv->max_speed_hz;
425	if (xfer->speed_hz)
426		speed_hz = xfer->speed_hz;
427
428	ret = qcom_qspi_set_speed(ctrl, speed_hz);
429	if (ret)
430		return ret;
431
432	spin_lock_irqsave(&ctrl->lock, flags);
433	mstr_cfg = readl(ctrl->base + MSTR_CONFIG);
434
435	/* We are half duplex, so either rx or tx will be set */
436	if (xfer->rx_buf) {
437		ctrl->xfer.dir = QSPI_READ;
438		ctrl->xfer.buswidth = xfer->rx_nbits;
439		ctrl->xfer.rx_buf = xfer->rx_buf;
440	} else {
441		ctrl->xfer.dir = QSPI_WRITE;
442		ctrl->xfer.buswidth = xfer->tx_nbits;
443		ctrl->xfer.tx_buf = xfer->tx_buf;
444	}
445	ctrl->xfer.is_last = list_is_last(&xfer->transfer_list,
446					  &host->cur_msg->transfers);
447	ctrl->xfer.rem_bytes = xfer->len;
448
449	if (xfer->rx_sg.nents || xfer->tx_sg.nents) {
450		/* do DMA transfer */
451		if (!(mstr_cfg & DMA_ENABLE)) {
452			mstr_cfg |= DMA_ENABLE;
453			writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
454		}
455
456		ret = qcom_qspi_setup_dma_desc(ctrl, xfer);
457		if (ret != -EAGAIN) {
458			if (!ret) {
459				dma_wmb();
460				qcom_qspi_dma_xfer(ctrl);
461			}
462			goto exit;
463		}
464		dev_warn_once(ctrl->dev, "DMA failure, falling back to PIO\n");
465		ret = 0; /* We'll retry w/ PIO */
466	}
467
468	if (mstr_cfg & DMA_ENABLE) {
469		mstr_cfg &= ~DMA_ENABLE;
470		writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
471	}
472	qcom_qspi_pio_xfer(ctrl);
473
474exit:
475	spin_unlock_irqrestore(&ctrl->lock, flags);
476
477	if (ret)
478		return ret;
479
480	/* We'll call spi_finalize_current_transfer() when done */
481	return 1;
482}
483
484static int qcom_qspi_prepare_message(struct spi_controller *host,
485				     struct spi_message *message)
486{
487	u32 mstr_cfg;
488	struct qcom_qspi *ctrl;
489	int tx_data_oe_delay = 1;
490	int tx_data_delay = 1;
491	unsigned long flags;
492
493	ctrl = spi_controller_get_devdata(host);
494	spin_lock_irqsave(&ctrl->lock, flags);
495
496	mstr_cfg = readl(ctrl->base + MSTR_CONFIG);
497	mstr_cfg &= ~CHIP_SELECT_NUM;
498	if (spi_get_chipselect(message->spi, 0))
499		mstr_cfg |= CHIP_SELECT_NUM;
500
501	mstr_cfg |= FB_CLK_EN | PIN_WPN | PIN_HOLDN | SBL_EN | FULL_CYCLE_MODE;
502	mstr_cfg &= ~(SPI_MODE_MSK | TX_DATA_OE_DELAY_MSK | TX_DATA_DELAY_MSK);
503	mstr_cfg |= message->spi->mode << SPI_MODE_SHFT;
504	mstr_cfg |= tx_data_oe_delay << TX_DATA_OE_DELAY_SHFT;
505	mstr_cfg |= tx_data_delay << TX_DATA_DELAY_SHFT;
506	mstr_cfg &= ~DMA_ENABLE;
507
508	writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
509	spin_unlock_irqrestore(&ctrl->lock, flags);
510
511	return 0;
512}
513
514static int qcom_qspi_alloc_dma(struct qcom_qspi *ctrl)
515{
516	ctrl->dma_cmd_pool = dmam_pool_create("qspi cmd desc pool",
517		ctrl->dev, sizeof(struct qspi_cmd_desc), 0, 0);
518	if (!ctrl->dma_cmd_pool)
519		return -ENOMEM;
520
521	return 0;
522}
523
524static irqreturn_t pio_read(struct qcom_qspi *ctrl)
525{
526	u32 rd_fifo_status;
527	u32 rd_fifo;
528	unsigned int wr_cnts;
529	unsigned int bytes_to_read;
530	unsigned int words_to_read;
531	u32 *word_buf;
532	u8 *byte_buf;
533	int i;
534
535	rd_fifo_status = readl(ctrl->base + RD_FIFO_STATUS);
536
537	if (!(rd_fifo_status & FIFO_RDY)) {
538		dev_dbg(ctrl->dev, "Spurious IRQ %#x\n", rd_fifo_status);
539		return IRQ_NONE;
540	}
541
542	wr_cnts = (rd_fifo_status & WR_CNTS_MSK) >> WR_CNTS_SHFT;
543	wr_cnts = min(wr_cnts, ctrl->xfer.rem_bytes);
544
545	words_to_read = wr_cnts / QSPI_BYTES_PER_WORD;
546	bytes_to_read = wr_cnts % QSPI_BYTES_PER_WORD;
547
548	if (words_to_read) {
549		word_buf = ctrl->xfer.rx_buf;
550		ctrl->xfer.rem_bytes -= words_to_read * QSPI_BYTES_PER_WORD;
551		ioread32_rep(ctrl->base + RD_FIFO, word_buf, words_to_read);
552		ctrl->xfer.rx_buf = word_buf + words_to_read;
553	}
554
555	if (bytes_to_read) {
556		byte_buf = ctrl->xfer.rx_buf;
557		rd_fifo = readl(ctrl->base + RD_FIFO);
558		ctrl->xfer.rem_bytes -= bytes_to_read;
559		for (i = 0; i < bytes_to_read; i++)
560			*byte_buf++ = rd_fifo >> (i * BITS_PER_BYTE);
561		ctrl->xfer.rx_buf = byte_buf;
562	}
563
564	return IRQ_HANDLED;
565}
566
567static irqreturn_t pio_write(struct qcom_qspi *ctrl)
568{
569	const void *xfer_buf = ctrl->xfer.tx_buf;
570	const int *word_buf;
571	const char *byte_buf;
572	unsigned int wr_fifo_bytes;
573	unsigned int wr_fifo_words;
574	unsigned int wr_size;
575	unsigned int rem_words;
576
577	wr_fifo_bytes = readl(ctrl->base + PIO_XFER_STATUS);
578	wr_fifo_bytes >>= WR_FIFO_BYTES_SHFT;
579
580	if (ctrl->xfer.rem_bytes < QSPI_BYTES_PER_WORD) {
581		/* Process the last 1-3 bytes */
582		wr_size = min(wr_fifo_bytes, ctrl->xfer.rem_bytes);
583		ctrl->xfer.rem_bytes -= wr_size;
584
585		byte_buf = xfer_buf;
586		while (wr_size--)
587			writel(*byte_buf++,
588			       ctrl->base + PIO_DATAOUT_1B);
589		ctrl->xfer.tx_buf = byte_buf;
590	} else {
591		/*
592		 * Process all the whole words; to keep things simple we'll
593		 * just wait for the next interrupt to handle the last 1-3
594		 * bytes if we don't have an even number of words.
595		 */
596		rem_words = ctrl->xfer.rem_bytes / QSPI_BYTES_PER_WORD;
597		wr_fifo_words = wr_fifo_bytes / QSPI_BYTES_PER_WORD;
598
599		wr_size = min(rem_words, wr_fifo_words);
600		ctrl->xfer.rem_bytes -= wr_size * QSPI_BYTES_PER_WORD;
601
602		word_buf = xfer_buf;
603		iowrite32_rep(ctrl->base + PIO_DATAOUT_4B, word_buf, wr_size);
604		ctrl->xfer.tx_buf = word_buf + wr_size;
605
606	}
607
608	return IRQ_HANDLED;
609}
610
611static irqreturn_t qcom_qspi_irq(int irq, void *dev_id)
612{
613	u32 int_status;
614	struct qcom_qspi *ctrl = dev_id;
615	irqreturn_t ret = IRQ_NONE;
616
617	spin_lock(&ctrl->lock);
618
619	int_status = readl(ctrl->base + MSTR_INT_STATUS);
620	writel(int_status, ctrl->base + MSTR_INT_STATUS);
621
622	/* Ignore disabled interrupts */
623	int_status &= readl(ctrl->base + MSTR_INT_EN);
624
625	/* PIO mode handling */
626	if (ctrl->xfer.dir == QSPI_WRITE) {
627		if (int_status & WR_FIFO_EMPTY)
628			ret = pio_write(ctrl);
629	} else {
630		if (int_status & RESP_FIFO_RDY)
631			ret = pio_read(ctrl);
632	}
633
634	if (int_status & QSPI_ERR_IRQS) {
635		if (int_status & RESP_FIFO_UNDERRUN)
636			dev_err(ctrl->dev, "IRQ error: FIFO underrun\n");
637		if (int_status & WR_FIFO_OVERRUN)
638			dev_err(ctrl->dev, "IRQ error: FIFO overrun\n");
639		if (int_status & HRESP_FROM_NOC_ERR)
640			dev_err(ctrl->dev, "IRQ error: NOC response error\n");
641		ret = IRQ_HANDLED;
642	}
643
644	if (!ctrl->xfer.rem_bytes) {
645		writel(0, ctrl->base + MSTR_INT_EN);
646		spi_finalize_current_transfer(dev_get_drvdata(ctrl->dev));
647	}
648
649	/* DMA mode handling */
650	if (int_status & DMA_CHAIN_DONE) {
651		int i;
652
653		writel(0, ctrl->base + MSTR_INT_EN);
654		ctrl->xfer.rem_bytes = 0;
655
656		for (i = 0; i < ctrl->n_cmd_desc; i++)
657			dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i],
658					  ctrl->dma_cmd_desc[i]);
659		ctrl->n_cmd_desc = 0;
660
661		ret = IRQ_HANDLED;
662		spi_finalize_current_transfer(dev_get_drvdata(ctrl->dev));
663	}
664
665	spin_unlock(&ctrl->lock);
666	return ret;
667}
668
669static int qcom_qspi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
670{
671	/*
672	 * If qcom_qspi_can_dma() is going to return false we don't need to
673	 * adjust anything.
674	 */
675	if (op->data.nbytes <= QSPI_MAX_BYTES_FIFO)
676		return 0;
677
678	/*
679	 * When reading, the transfer needs to be a multiple of 4 bytes so
680	 * shrink the transfer if that's not true. The caller will then do a
681	 * second transfer to finish things up.
682	 */
683	if (op->data.dir == SPI_MEM_DATA_IN && (op->data.nbytes & 0x3))
684		op->data.nbytes &= ~0x3;
685
686	return 0;
687}
688
689static const struct spi_controller_mem_ops qcom_qspi_mem_ops = {
690	.adjust_op_size = qcom_qspi_adjust_op_size,
691};
692
693static int qcom_qspi_probe(struct platform_device *pdev)
694{
695	int ret;
696	struct device *dev;
697	struct spi_controller *host;
698	struct qcom_qspi *ctrl;
699
700	dev = &pdev->dev;
701
702	host = devm_spi_alloc_host(dev, sizeof(*ctrl));
703	if (!host)
704		return -ENOMEM;
705
706	platform_set_drvdata(pdev, host);
707
708	ctrl = spi_controller_get_devdata(host);
709
710	spin_lock_init(&ctrl->lock);
711	ctrl->dev = dev;
712	ctrl->base = devm_platform_ioremap_resource(pdev, 0);
713	if (IS_ERR(ctrl->base))
714		return PTR_ERR(ctrl->base);
715
716	ctrl->clks = devm_kcalloc(dev, QSPI_NUM_CLKS,
717				  sizeof(*ctrl->clks), GFP_KERNEL);
718	if (!ctrl->clks)
719		return -ENOMEM;
720
721	ctrl->clks[QSPI_CLK_CORE].id = "core";
722	ctrl->clks[QSPI_CLK_IFACE].id = "iface";
723	ret = devm_clk_bulk_get(dev, QSPI_NUM_CLKS, ctrl->clks);
724	if (ret)
725		return ret;
726
727	ctrl->icc_path_cpu_to_qspi = devm_of_icc_get(dev, "qspi-config");
728	if (IS_ERR(ctrl->icc_path_cpu_to_qspi))
729		return dev_err_probe(dev, PTR_ERR(ctrl->icc_path_cpu_to_qspi),
730				     "Failed to get cpu path\n");
731
732	/* Set BW vote for register access */
733	ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, Bps_to_icc(1000),
734				Bps_to_icc(1000));
735	if (ret) {
736		dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu: %d\n",
737				__func__, ret);
738		return ret;
739	}
740
741	ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
742	if (ret) {
743		dev_err(ctrl->dev, "%s: ICC disable failed for cpu: %d\n",
744				__func__, ret);
745		return ret;
746	}
747
748	ret = platform_get_irq(pdev, 0);
749	if (ret < 0)
750		return ret;
751	ret = devm_request_irq(dev, ret, qcom_qspi_irq, 0, dev_name(dev), ctrl);
752	if (ret) {
753		dev_err(dev, "Failed to request irq %d\n", ret);
754		return ret;
755	}
756
757	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
758	if (ret)
759		return dev_err_probe(dev, ret, "could not set DMA mask\n");
760
761	host->max_speed_hz = 300000000;
762	host->max_dma_len = 65536; /* as per HPG */
763	host->dma_alignment = QSPI_ALIGN_REQ;
764	host->num_chipselect = QSPI_NUM_CS;
765	host->bus_num = -1;
766	host->dev.of_node = pdev->dev.of_node;
767	host->mode_bits = SPI_MODE_0 |
768			  SPI_TX_DUAL | SPI_RX_DUAL |
769			  SPI_TX_QUAD | SPI_RX_QUAD;
770	host->flags = SPI_CONTROLLER_HALF_DUPLEX;
771	host->prepare_message = qcom_qspi_prepare_message;
772	host->transfer_one = qcom_qspi_transfer_one;
773	host->handle_err = qcom_qspi_handle_err;
774	if (of_property_read_bool(pdev->dev.of_node, "iommus"))
775		host->can_dma = qcom_qspi_can_dma;
776	host->auto_runtime_pm = true;
777	host->mem_ops = &qcom_qspi_mem_ops;
778
779	ret = devm_pm_opp_set_clkname(&pdev->dev, "core");
780	if (ret)
781		return ret;
782	/* OPP table is optional */
783	ret = devm_pm_opp_of_add_table(&pdev->dev);
784	if (ret && ret != -ENODEV) {
785		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
786		return ret;
787	}
788
789	ret = qcom_qspi_alloc_dma(ctrl);
790	if (ret)
791		return ret;
792
793	pm_runtime_use_autosuspend(dev);
794	pm_runtime_set_autosuspend_delay(dev, 250);
795	pm_runtime_enable(dev);
796
797	ret = spi_register_controller(host);
798	if (!ret)
799		return 0;
800
801	pm_runtime_disable(dev);
802
803	return ret;
804}
805
806static void qcom_qspi_remove(struct platform_device *pdev)
807{
808	struct spi_controller *host = platform_get_drvdata(pdev);
809
810	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
811	spi_unregister_controller(host);
812
813	pm_runtime_disable(&pdev->dev);
814}
815
816static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
817{
818	struct spi_controller *host = dev_get_drvdata(dev);
819	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
820	int ret;
821
822	/* Drop the performance state vote */
823	dev_pm_opp_set_rate(dev, 0);
824	clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks);
825
826	ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
827	if (ret) {
828		dev_err_ratelimited(ctrl->dev, "%s: ICC disable failed for cpu: %d\n",
829			__func__, ret);
830		return ret;
831	}
832
833	pinctrl_pm_select_sleep_state(dev);
834
835	return 0;
836}
837
838static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev)
839{
840	struct spi_controller *host = dev_get_drvdata(dev);
841	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
842	int ret;
843
844	pinctrl_pm_select_default_state(dev);
845
846	ret = icc_enable(ctrl->icc_path_cpu_to_qspi);
847	if (ret) {
848		dev_err_ratelimited(ctrl->dev, "%s: ICC enable failed for cpu: %d\n",
849			__func__, ret);
850		return ret;
851	}
852
853	ret = clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
854	if (ret)
855		return ret;
856
857	return dev_pm_opp_set_rate(dev, ctrl->last_speed * 4);
858}
859
860static int __maybe_unused qcom_qspi_suspend(struct device *dev)
861{
862	struct spi_controller *host = dev_get_drvdata(dev);
863	int ret;
864
865	ret = spi_controller_suspend(host);
866	if (ret)
867		return ret;
868
869	ret = pm_runtime_force_suspend(dev);
870	if (ret)
871		spi_controller_resume(host);
872
873	return ret;
874}
875
876static int __maybe_unused qcom_qspi_resume(struct device *dev)
877{
878	struct spi_controller *host = dev_get_drvdata(dev);
879	int ret;
880
881	ret = pm_runtime_force_resume(dev);
882	if (ret)
883		return ret;
884
885	ret = spi_controller_resume(host);
886	if (ret)
887		pm_runtime_force_suspend(dev);
888
889	return ret;
890}
891
892static const struct dev_pm_ops qcom_qspi_dev_pm_ops = {
893	SET_RUNTIME_PM_OPS(qcom_qspi_runtime_suspend,
894			   qcom_qspi_runtime_resume, NULL)
895	SET_SYSTEM_SLEEP_PM_OPS(qcom_qspi_suspend, qcom_qspi_resume)
896};
897
898static const struct of_device_id qcom_qspi_dt_match[] = {
899	{ .compatible = "qcom,qspi-v1", },
900	{ }
901};
902MODULE_DEVICE_TABLE(of, qcom_qspi_dt_match);
903
904static struct platform_driver qcom_qspi_driver = {
905	.driver = {
906		.name		= "qcom_qspi",
907		.pm		= &qcom_qspi_dev_pm_ops,
908		.of_match_table = qcom_qspi_dt_match,
909	},
910	.probe = qcom_qspi_probe,
911	.remove_new = qcom_qspi_remove,
912};
913module_platform_driver(qcom_qspi_driver);
914
915MODULE_DESCRIPTION("SPI driver for QSPI cores");
916MODULE_LICENSE("GPL v2");
917