xref: /linux/drivers/spi/spi-mt65xx.c (revision 9a6b55ac)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015 MediaTek Inc.
4  * Author: Leilk Liu <leilk.liu@mediatek.com>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/device.h>
9 #include <linux/err.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/ioport.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_gpio.h>
16 #include <linux/platform_device.h>
17 #include <linux/platform_data/spi-mt65xx.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/spi/spi.h>
20 #include <linux/dma-mapping.h>
21 
22 #define SPI_CFG0_REG                      0x0000
23 #define SPI_CFG1_REG                      0x0004
24 #define SPI_TX_SRC_REG                    0x0008
25 #define SPI_RX_DST_REG                    0x000c
26 #define SPI_TX_DATA_REG                   0x0010
27 #define SPI_RX_DATA_REG                   0x0014
28 #define SPI_CMD_REG                       0x0018
29 #define SPI_STATUS0_REG                   0x001c
30 #define SPI_PAD_SEL_REG                   0x0024
31 #define SPI_CFG2_REG                      0x0028
32 #define SPI_TX_SRC_REG_64                 0x002c
33 #define SPI_RX_DST_REG_64                 0x0030
34 
35 #define SPI_CFG0_SCK_HIGH_OFFSET          0
36 #define SPI_CFG0_SCK_LOW_OFFSET           8
37 #define SPI_CFG0_CS_HOLD_OFFSET           16
38 #define SPI_CFG0_CS_SETUP_OFFSET          24
39 #define SPI_ADJUST_CFG0_SCK_LOW_OFFSET    16
40 #define SPI_ADJUST_CFG0_CS_HOLD_OFFSET    0
41 #define SPI_ADJUST_CFG0_CS_SETUP_OFFSET   16
42 
43 #define SPI_CFG1_CS_IDLE_OFFSET           0
44 #define SPI_CFG1_PACKET_LOOP_OFFSET       8
45 #define SPI_CFG1_PACKET_LENGTH_OFFSET     16
46 #define SPI_CFG1_GET_TICK_DLY_OFFSET      30
47 
48 #define SPI_CFG1_CS_IDLE_MASK             0xff
49 #define SPI_CFG1_PACKET_LOOP_MASK         0xff00
50 #define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
51 
52 #define SPI_CMD_ACT                  BIT(0)
53 #define SPI_CMD_RESUME               BIT(1)
54 #define SPI_CMD_RST                  BIT(2)
55 #define SPI_CMD_PAUSE_EN             BIT(4)
56 #define SPI_CMD_DEASSERT             BIT(5)
57 #define SPI_CMD_SAMPLE_SEL           BIT(6)
58 #define SPI_CMD_CS_POL               BIT(7)
59 #define SPI_CMD_CPHA                 BIT(8)
60 #define SPI_CMD_CPOL                 BIT(9)
61 #define SPI_CMD_RX_DMA               BIT(10)
62 #define SPI_CMD_TX_DMA               BIT(11)
63 #define SPI_CMD_TXMSBF               BIT(12)
64 #define SPI_CMD_RXMSBF               BIT(13)
65 #define SPI_CMD_RX_ENDIAN            BIT(14)
66 #define SPI_CMD_TX_ENDIAN            BIT(15)
67 #define SPI_CMD_FINISH_IE            BIT(16)
68 #define SPI_CMD_PAUSE_IE             BIT(17)
69 
70 #define MT8173_SPI_MAX_PAD_SEL 3
71 
72 #define MTK_SPI_PAUSE_INT_STATUS 0x2
73 
74 #define MTK_SPI_IDLE 0
75 #define MTK_SPI_PAUSED 1
76 
77 #define MTK_SPI_MAX_FIFO_SIZE 32U
78 #define MTK_SPI_PACKET_SIZE 1024
79 #define MTK_SPI_32BITS_MASK  (0xffffffff)
80 
81 #define DMA_ADDR_EXT_BITS (36)
82 #define DMA_ADDR_DEF_BITS (32)
83 
84 struct mtk_spi_compatible {
85 	bool need_pad_sel;
86 	/* Must explicitly send dummy Tx bytes to do Rx only transfer */
87 	bool must_tx;
88 	/* some IC design adjust cfg register to enhance time accuracy */
89 	bool enhance_timing;
90 	/* some IC support DMA addr extension */
91 	bool dma_ext;
92 };
93 
94 struct mtk_spi {
95 	void __iomem *base;
96 	u32 state;
97 	int pad_num;
98 	u32 *pad_sel;
99 	struct clk *parent_clk, *sel_clk, *spi_clk;
100 	struct spi_transfer *cur_transfer;
101 	u32 xfer_len;
102 	u32 num_xfered;
103 	struct scatterlist *tx_sgl, *rx_sgl;
104 	u32 tx_sgl_len, rx_sgl_len;
105 	const struct mtk_spi_compatible *dev_comp;
106 };
107 
108 static const struct mtk_spi_compatible mtk_common_compat;
109 
110 static const struct mtk_spi_compatible mt2712_compat = {
111 	.must_tx = true,
112 };
113 
114 static const struct mtk_spi_compatible mt6765_compat = {
115 	.need_pad_sel = true,
116 	.must_tx = true,
117 	.enhance_timing = true,
118 	.dma_ext = true,
119 };
120 
121 static const struct mtk_spi_compatible mt7622_compat = {
122 	.must_tx = true,
123 	.enhance_timing = true,
124 };
125 
126 static const struct mtk_spi_compatible mt8173_compat = {
127 	.need_pad_sel = true,
128 	.must_tx = true,
129 };
130 
131 static const struct mtk_spi_compatible mt8183_compat = {
132 	.need_pad_sel = true,
133 	.must_tx = true,
134 	.enhance_timing = true,
135 };
136 
137 /*
138  * A piece of default chip info unless the platform
139  * supplies it.
140  */
141 static const struct mtk_chip_config mtk_default_chip_info = {
142 	.sample_sel = 0,
143 };
144 
145 static const struct of_device_id mtk_spi_of_match[] = {
146 	{ .compatible = "mediatek,mt2701-spi",
147 		.data = (void *)&mtk_common_compat,
148 	},
149 	{ .compatible = "mediatek,mt2712-spi",
150 		.data = (void *)&mt2712_compat,
151 	},
152 	{ .compatible = "mediatek,mt6589-spi",
153 		.data = (void *)&mtk_common_compat,
154 	},
155 	{ .compatible = "mediatek,mt6765-spi",
156 		.data = (void *)&mt6765_compat,
157 	},
158 	{ .compatible = "mediatek,mt7622-spi",
159 		.data = (void *)&mt7622_compat,
160 	},
161 	{ .compatible = "mediatek,mt7629-spi",
162 		.data = (void *)&mt7622_compat,
163 	},
164 	{ .compatible = "mediatek,mt8135-spi",
165 		.data = (void *)&mtk_common_compat,
166 	},
167 	{ .compatible = "mediatek,mt8173-spi",
168 		.data = (void *)&mt8173_compat,
169 	},
170 	{ .compatible = "mediatek,mt8183-spi",
171 		.data = (void *)&mt8183_compat,
172 	},
173 	{}
174 };
175 MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
176 
177 static void mtk_spi_reset(struct mtk_spi *mdata)
178 {
179 	u32 reg_val;
180 
181 	/* set the software reset bit in SPI_CMD_REG. */
182 	reg_val = readl(mdata->base + SPI_CMD_REG);
183 	reg_val |= SPI_CMD_RST;
184 	writel(reg_val, mdata->base + SPI_CMD_REG);
185 
186 	reg_val = readl(mdata->base + SPI_CMD_REG);
187 	reg_val &= ~SPI_CMD_RST;
188 	writel(reg_val, mdata->base + SPI_CMD_REG);
189 }
190 
191 static int mtk_spi_prepare_message(struct spi_master *master,
192 				   struct spi_message *msg)
193 {
194 	u16 cpha, cpol;
195 	u32 reg_val;
196 	struct spi_device *spi = msg->spi;
197 	struct mtk_chip_config *chip_config = spi->controller_data;
198 	struct mtk_spi *mdata = spi_master_get_devdata(master);
199 
200 	cpha = spi->mode & SPI_CPHA ? 1 : 0;
201 	cpol = spi->mode & SPI_CPOL ? 1 : 0;
202 
203 	reg_val = readl(mdata->base + SPI_CMD_REG);
204 	if (cpha)
205 		reg_val |= SPI_CMD_CPHA;
206 	else
207 		reg_val &= ~SPI_CMD_CPHA;
208 	if (cpol)
209 		reg_val |= SPI_CMD_CPOL;
210 	else
211 		reg_val &= ~SPI_CMD_CPOL;
212 
213 	/* set the mlsbx and mlsbtx */
214 	if (spi->mode & SPI_LSB_FIRST) {
215 		reg_val &= ~SPI_CMD_TXMSBF;
216 		reg_val &= ~SPI_CMD_RXMSBF;
217 	} else {
218 		reg_val |= SPI_CMD_TXMSBF;
219 		reg_val |= SPI_CMD_RXMSBF;
220 	}
221 
222 	/* set the tx/rx endian */
223 #ifdef __LITTLE_ENDIAN
224 	reg_val &= ~SPI_CMD_TX_ENDIAN;
225 	reg_val &= ~SPI_CMD_RX_ENDIAN;
226 #else
227 	reg_val |= SPI_CMD_TX_ENDIAN;
228 	reg_val |= SPI_CMD_RX_ENDIAN;
229 #endif
230 
231 	if (mdata->dev_comp->enhance_timing) {
232 		/* set CS polarity */
233 		if (spi->mode & SPI_CS_HIGH)
234 			reg_val |= SPI_CMD_CS_POL;
235 		else
236 			reg_val &= ~SPI_CMD_CS_POL;
237 
238 		if (chip_config->sample_sel)
239 			reg_val |= SPI_CMD_SAMPLE_SEL;
240 		else
241 			reg_val &= ~SPI_CMD_SAMPLE_SEL;
242 	}
243 
244 	/* set finish and pause interrupt always enable */
245 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;
246 
247 	/* disable dma mode */
248 	reg_val &= ~(SPI_CMD_TX_DMA | SPI_CMD_RX_DMA);
249 
250 	/* disable deassert mode */
251 	reg_val &= ~SPI_CMD_DEASSERT;
252 
253 	writel(reg_val, mdata->base + SPI_CMD_REG);
254 
255 	/* pad select */
256 	if (mdata->dev_comp->need_pad_sel)
257 		writel(mdata->pad_sel[spi->chip_select],
258 		       mdata->base + SPI_PAD_SEL_REG);
259 
260 	return 0;
261 }
262 
263 static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
264 {
265 	u32 reg_val;
266 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
267 
268 	if (spi->mode & SPI_CS_HIGH)
269 		enable = !enable;
270 
271 	reg_val = readl(mdata->base + SPI_CMD_REG);
272 	if (!enable) {
273 		reg_val |= SPI_CMD_PAUSE_EN;
274 		writel(reg_val, mdata->base + SPI_CMD_REG);
275 	} else {
276 		reg_val &= ~SPI_CMD_PAUSE_EN;
277 		writel(reg_val, mdata->base + SPI_CMD_REG);
278 		mdata->state = MTK_SPI_IDLE;
279 		mtk_spi_reset(mdata);
280 	}
281 }
282 
283 static void mtk_spi_prepare_transfer(struct spi_master *master,
284 				     struct spi_transfer *xfer)
285 {
286 	u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0;
287 	struct mtk_spi *mdata = spi_master_get_devdata(master);
288 
289 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
290 	if (xfer->speed_hz < spi_clk_hz / 2)
291 		div = DIV_ROUND_UP(spi_clk_hz, xfer->speed_hz);
292 	else
293 		div = 1;
294 
295 	sck_time = (div + 1) / 2;
296 	cs_time = sck_time * 2;
297 
298 	if (mdata->dev_comp->enhance_timing) {
299 		reg_val |= (((sck_time - 1) & 0xffff)
300 			   << SPI_CFG0_SCK_HIGH_OFFSET);
301 		reg_val |= (((sck_time - 1) & 0xffff)
302 			   << SPI_ADJUST_CFG0_SCK_LOW_OFFSET);
303 		writel(reg_val, mdata->base + SPI_CFG2_REG);
304 		reg_val |= (((cs_time - 1) & 0xffff)
305 			   << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
306 		reg_val |= (((cs_time - 1) & 0xffff)
307 			   << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
308 		writel(reg_val, mdata->base + SPI_CFG0_REG);
309 	} else {
310 		reg_val |= (((sck_time - 1) & 0xff)
311 			   << SPI_CFG0_SCK_HIGH_OFFSET);
312 		reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
313 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
314 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
315 		writel(reg_val, mdata->base + SPI_CFG0_REG);
316 	}
317 
318 	reg_val = readl(mdata->base + SPI_CFG1_REG);
319 	reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
320 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
321 	writel(reg_val, mdata->base + SPI_CFG1_REG);
322 }
323 
324 static void mtk_spi_setup_packet(struct spi_master *master)
325 {
326 	u32 packet_size, packet_loop, reg_val;
327 	struct mtk_spi *mdata = spi_master_get_devdata(master);
328 
329 	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
330 	packet_loop = mdata->xfer_len / packet_size;
331 
332 	reg_val = readl(mdata->base + SPI_CFG1_REG);
333 	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
334 	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
335 	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
336 	writel(reg_val, mdata->base + SPI_CFG1_REG);
337 }
338 
339 static void mtk_spi_enable_transfer(struct spi_master *master)
340 {
341 	u32 cmd;
342 	struct mtk_spi *mdata = spi_master_get_devdata(master);
343 
344 	cmd = readl(mdata->base + SPI_CMD_REG);
345 	if (mdata->state == MTK_SPI_IDLE)
346 		cmd |= SPI_CMD_ACT;
347 	else
348 		cmd |= SPI_CMD_RESUME;
349 	writel(cmd, mdata->base + SPI_CMD_REG);
350 }
351 
352 static int mtk_spi_get_mult_delta(u32 xfer_len)
353 {
354 	u32 mult_delta;
355 
356 	if (xfer_len > MTK_SPI_PACKET_SIZE)
357 		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
358 	else
359 		mult_delta = 0;
360 
361 	return mult_delta;
362 }
363 
364 static void mtk_spi_update_mdata_len(struct spi_master *master)
365 {
366 	int mult_delta;
367 	struct mtk_spi *mdata = spi_master_get_devdata(master);
368 
369 	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
370 		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
371 			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
372 			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
373 			mdata->rx_sgl_len = mult_delta;
374 			mdata->tx_sgl_len -= mdata->xfer_len;
375 		} else {
376 			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
377 			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
378 			mdata->tx_sgl_len = mult_delta;
379 			mdata->rx_sgl_len -= mdata->xfer_len;
380 		}
381 	} else if (mdata->tx_sgl_len) {
382 		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
383 		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
384 		mdata->tx_sgl_len = mult_delta;
385 	} else if (mdata->rx_sgl_len) {
386 		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
387 		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
388 		mdata->rx_sgl_len = mult_delta;
389 	}
390 }
391 
392 static void mtk_spi_setup_dma_addr(struct spi_master *master,
393 				   struct spi_transfer *xfer)
394 {
395 	struct mtk_spi *mdata = spi_master_get_devdata(master);
396 
397 	if (mdata->tx_sgl) {
398 		writel((u32)(xfer->tx_dma & MTK_SPI_32BITS_MASK),
399 		       mdata->base + SPI_TX_SRC_REG);
400 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
401 		if (mdata->dev_comp->dma_ext)
402 			writel((u32)(xfer->tx_dma >> 32),
403 			       mdata->base + SPI_TX_SRC_REG_64);
404 #endif
405 	}
406 
407 	if (mdata->rx_sgl) {
408 		writel((u32)(xfer->rx_dma & MTK_SPI_32BITS_MASK),
409 		       mdata->base + SPI_RX_DST_REG);
410 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
411 		if (mdata->dev_comp->dma_ext)
412 			writel((u32)(xfer->rx_dma >> 32),
413 			       mdata->base + SPI_RX_DST_REG_64);
414 #endif
415 	}
416 }
417 
418 static int mtk_spi_fifo_transfer(struct spi_master *master,
419 				 struct spi_device *spi,
420 				 struct spi_transfer *xfer)
421 {
422 	int cnt, remainder;
423 	u32 reg_val;
424 	struct mtk_spi *mdata = spi_master_get_devdata(master);
425 
426 	mdata->cur_transfer = xfer;
427 	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
428 	mdata->num_xfered = 0;
429 	mtk_spi_prepare_transfer(master, xfer);
430 	mtk_spi_setup_packet(master);
431 
432 	cnt = xfer->len / 4;
433 	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
434 
435 	remainder = xfer->len % 4;
436 	if (remainder > 0) {
437 		reg_val = 0;
438 		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
439 		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
440 	}
441 
442 	mtk_spi_enable_transfer(master);
443 
444 	return 1;
445 }
446 
447 static int mtk_spi_dma_transfer(struct spi_master *master,
448 				struct spi_device *spi,
449 				struct spi_transfer *xfer)
450 {
451 	int cmd;
452 	struct mtk_spi *mdata = spi_master_get_devdata(master);
453 
454 	mdata->tx_sgl = NULL;
455 	mdata->rx_sgl = NULL;
456 	mdata->tx_sgl_len = 0;
457 	mdata->rx_sgl_len = 0;
458 	mdata->cur_transfer = xfer;
459 	mdata->num_xfered = 0;
460 
461 	mtk_spi_prepare_transfer(master, xfer);
462 
463 	cmd = readl(mdata->base + SPI_CMD_REG);
464 	if (xfer->tx_buf)
465 		cmd |= SPI_CMD_TX_DMA;
466 	if (xfer->rx_buf)
467 		cmd |= SPI_CMD_RX_DMA;
468 	writel(cmd, mdata->base + SPI_CMD_REG);
469 
470 	if (xfer->tx_buf)
471 		mdata->tx_sgl = xfer->tx_sg.sgl;
472 	if (xfer->rx_buf)
473 		mdata->rx_sgl = xfer->rx_sg.sgl;
474 
475 	if (mdata->tx_sgl) {
476 		xfer->tx_dma = sg_dma_address(mdata->tx_sgl);
477 		mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
478 	}
479 	if (mdata->rx_sgl) {
480 		xfer->rx_dma = sg_dma_address(mdata->rx_sgl);
481 		mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
482 	}
483 
484 	mtk_spi_update_mdata_len(master);
485 	mtk_spi_setup_packet(master);
486 	mtk_spi_setup_dma_addr(master, xfer);
487 	mtk_spi_enable_transfer(master);
488 
489 	return 1;
490 }
491 
492 static int mtk_spi_transfer_one(struct spi_master *master,
493 				struct spi_device *spi,
494 				struct spi_transfer *xfer)
495 {
496 	if (master->can_dma(master, spi, xfer))
497 		return mtk_spi_dma_transfer(master, spi, xfer);
498 	else
499 		return mtk_spi_fifo_transfer(master, spi, xfer);
500 }
501 
502 static bool mtk_spi_can_dma(struct spi_master *master,
503 			    struct spi_device *spi,
504 			    struct spi_transfer *xfer)
505 {
506 	/* Buffers for DMA transactions must be 4-byte aligned */
507 	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
508 		(unsigned long)xfer->tx_buf % 4 == 0 &&
509 		(unsigned long)xfer->rx_buf % 4 == 0);
510 }
511 
512 static int mtk_spi_setup(struct spi_device *spi)
513 {
514 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
515 
516 	if (!spi->controller_data)
517 		spi->controller_data = (void *)&mtk_default_chip_info;
518 
519 	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
520 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
521 
522 	return 0;
523 }
524 
525 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
526 {
527 	u32 cmd, reg_val, cnt, remainder, len;
528 	struct spi_master *master = dev_id;
529 	struct mtk_spi *mdata = spi_master_get_devdata(master);
530 	struct spi_transfer *trans = mdata->cur_transfer;
531 
532 	reg_val = readl(mdata->base + SPI_STATUS0_REG);
533 	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
534 		mdata->state = MTK_SPI_PAUSED;
535 	else
536 		mdata->state = MTK_SPI_IDLE;
537 
538 	if (!master->can_dma(master, master->cur_msg->spi, trans)) {
539 		if (trans->rx_buf) {
540 			cnt = mdata->xfer_len / 4;
541 			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
542 				     trans->rx_buf + mdata->num_xfered, cnt);
543 			remainder = mdata->xfer_len % 4;
544 			if (remainder > 0) {
545 				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
546 				memcpy(trans->rx_buf +
547 					mdata->num_xfered +
548 					(cnt * 4),
549 					&reg_val,
550 					remainder);
551 			}
552 		}
553 
554 		mdata->num_xfered += mdata->xfer_len;
555 		if (mdata->num_xfered == trans->len) {
556 			spi_finalize_current_transfer(master);
557 			return IRQ_HANDLED;
558 		}
559 
560 		len = trans->len - mdata->num_xfered;
561 		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, len);
562 		mtk_spi_setup_packet(master);
563 
564 		cnt = mdata->xfer_len / 4;
565 		iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
566 				trans->tx_buf + mdata->num_xfered, cnt);
567 
568 		remainder = mdata->xfer_len % 4;
569 		if (remainder > 0) {
570 			reg_val = 0;
571 			memcpy(&reg_val,
572 				trans->tx_buf + (cnt * 4) + mdata->num_xfered,
573 				remainder);
574 			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
575 		}
576 
577 		mtk_spi_enable_transfer(master);
578 
579 		return IRQ_HANDLED;
580 	}
581 
582 	if (mdata->tx_sgl)
583 		trans->tx_dma += mdata->xfer_len;
584 	if (mdata->rx_sgl)
585 		trans->rx_dma += mdata->xfer_len;
586 
587 	if (mdata->tx_sgl && (mdata->tx_sgl_len == 0)) {
588 		mdata->tx_sgl = sg_next(mdata->tx_sgl);
589 		if (mdata->tx_sgl) {
590 			trans->tx_dma = sg_dma_address(mdata->tx_sgl);
591 			mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
592 		}
593 	}
594 	if (mdata->rx_sgl && (mdata->rx_sgl_len == 0)) {
595 		mdata->rx_sgl = sg_next(mdata->rx_sgl);
596 		if (mdata->rx_sgl) {
597 			trans->rx_dma = sg_dma_address(mdata->rx_sgl);
598 			mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
599 		}
600 	}
601 
602 	if (!mdata->tx_sgl && !mdata->rx_sgl) {
603 		/* spi disable dma */
604 		cmd = readl(mdata->base + SPI_CMD_REG);
605 		cmd &= ~SPI_CMD_TX_DMA;
606 		cmd &= ~SPI_CMD_RX_DMA;
607 		writel(cmd, mdata->base + SPI_CMD_REG);
608 
609 		spi_finalize_current_transfer(master);
610 		return IRQ_HANDLED;
611 	}
612 
613 	mtk_spi_update_mdata_len(master);
614 	mtk_spi_setup_packet(master);
615 	mtk_spi_setup_dma_addr(master, trans);
616 	mtk_spi_enable_transfer(master);
617 
618 	return IRQ_HANDLED;
619 }
620 
621 static int mtk_spi_probe(struct platform_device *pdev)
622 {
623 	struct spi_master *master;
624 	struct mtk_spi *mdata;
625 	const struct of_device_id *of_id;
626 	int i, irq, ret, addr_bits;
627 
628 	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
629 	if (!master) {
630 		dev_err(&pdev->dev, "failed to alloc spi master\n");
631 		return -ENOMEM;
632 	}
633 
634 	master->auto_runtime_pm = true;
635 	master->dev.of_node = pdev->dev.of_node;
636 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
637 
638 	master->set_cs = mtk_spi_set_cs;
639 	master->prepare_message = mtk_spi_prepare_message;
640 	master->transfer_one = mtk_spi_transfer_one;
641 	master->can_dma = mtk_spi_can_dma;
642 	master->setup = mtk_spi_setup;
643 
644 	of_id = of_match_node(mtk_spi_of_match, pdev->dev.of_node);
645 	if (!of_id) {
646 		dev_err(&pdev->dev, "failed to probe of_node\n");
647 		ret = -EINVAL;
648 		goto err_put_master;
649 	}
650 
651 	mdata = spi_master_get_devdata(master);
652 	mdata->dev_comp = of_id->data;
653 
654 	if (mdata->dev_comp->enhance_timing)
655 		master->mode_bits |= SPI_CS_HIGH;
656 
657 	if (mdata->dev_comp->must_tx)
658 		master->flags = SPI_MASTER_MUST_TX;
659 
660 	if (mdata->dev_comp->need_pad_sel) {
661 		mdata->pad_num = of_property_count_u32_elems(
662 			pdev->dev.of_node,
663 			"mediatek,pad-select");
664 		if (mdata->pad_num < 0) {
665 			dev_err(&pdev->dev,
666 				"No 'mediatek,pad-select' property\n");
667 			ret = -EINVAL;
668 			goto err_put_master;
669 		}
670 
671 		mdata->pad_sel = devm_kmalloc_array(&pdev->dev, mdata->pad_num,
672 						    sizeof(u32), GFP_KERNEL);
673 		if (!mdata->pad_sel) {
674 			ret = -ENOMEM;
675 			goto err_put_master;
676 		}
677 
678 		for (i = 0; i < mdata->pad_num; i++) {
679 			of_property_read_u32_index(pdev->dev.of_node,
680 						   "mediatek,pad-select",
681 						   i, &mdata->pad_sel[i]);
682 			if (mdata->pad_sel[i] > MT8173_SPI_MAX_PAD_SEL) {
683 				dev_err(&pdev->dev, "wrong pad-sel[%d]: %u\n",
684 					i, mdata->pad_sel[i]);
685 				ret = -EINVAL;
686 				goto err_put_master;
687 			}
688 		}
689 	}
690 
691 	platform_set_drvdata(pdev, master);
692 	mdata->base = devm_platform_ioremap_resource(pdev, 0);
693 	if (IS_ERR(mdata->base)) {
694 		ret = PTR_ERR(mdata->base);
695 		goto err_put_master;
696 	}
697 
698 	irq = platform_get_irq(pdev, 0);
699 	if (irq < 0) {
700 		ret = irq;
701 		goto err_put_master;
702 	}
703 
704 	if (!pdev->dev.dma_mask)
705 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
706 
707 	ret = devm_request_irq(&pdev->dev, irq, mtk_spi_interrupt,
708 			       IRQF_TRIGGER_NONE, dev_name(&pdev->dev), master);
709 	if (ret) {
710 		dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
711 		goto err_put_master;
712 	}
713 
714 	mdata->parent_clk = devm_clk_get(&pdev->dev, "parent-clk");
715 	if (IS_ERR(mdata->parent_clk)) {
716 		ret = PTR_ERR(mdata->parent_clk);
717 		dev_err(&pdev->dev, "failed to get parent-clk: %d\n", ret);
718 		goto err_put_master;
719 	}
720 
721 	mdata->sel_clk = devm_clk_get(&pdev->dev, "sel-clk");
722 	if (IS_ERR(mdata->sel_clk)) {
723 		ret = PTR_ERR(mdata->sel_clk);
724 		dev_err(&pdev->dev, "failed to get sel-clk: %d\n", ret);
725 		goto err_put_master;
726 	}
727 
728 	mdata->spi_clk = devm_clk_get(&pdev->dev, "spi-clk");
729 	if (IS_ERR(mdata->spi_clk)) {
730 		ret = PTR_ERR(mdata->spi_clk);
731 		dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
732 		goto err_put_master;
733 	}
734 
735 	ret = clk_prepare_enable(mdata->spi_clk);
736 	if (ret < 0) {
737 		dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
738 		goto err_put_master;
739 	}
740 
741 	ret = clk_set_parent(mdata->sel_clk, mdata->parent_clk);
742 	if (ret < 0) {
743 		dev_err(&pdev->dev, "failed to clk_set_parent (%d)\n", ret);
744 		clk_disable_unprepare(mdata->spi_clk);
745 		goto err_put_master;
746 	}
747 
748 	clk_disable_unprepare(mdata->spi_clk);
749 
750 	pm_runtime_enable(&pdev->dev);
751 
752 	ret = devm_spi_register_master(&pdev->dev, master);
753 	if (ret) {
754 		dev_err(&pdev->dev, "failed to register master (%d)\n", ret);
755 		goto err_disable_runtime_pm;
756 	}
757 
758 	if (mdata->dev_comp->need_pad_sel) {
759 		if (mdata->pad_num != master->num_chipselect) {
760 			dev_err(&pdev->dev,
761 				"pad_num does not match num_chipselect(%d != %d)\n",
762 				mdata->pad_num, master->num_chipselect);
763 			ret = -EINVAL;
764 			goto err_disable_runtime_pm;
765 		}
766 
767 		if (!master->cs_gpios && master->num_chipselect > 1) {
768 			dev_err(&pdev->dev,
769 				"cs_gpios not specified and num_chipselect > 1\n");
770 			ret = -EINVAL;
771 			goto err_disable_runtime_pm;
772 		}
773 
774 		if (master->cs_gpios) {
775 			for (i = 0; i < master->num_chipselect; i++) {
776 				ret = devm_gpio_request(&pdev->dev,
777 							master->cs_gpios[i],
778 							dev_name(&pdev->dev));
779 				if (ret) {
780 					dev_err(&pdev->dev,
781 						"can't get CS GPIO %i\n", i);
782 					goto err_disable_runtime_pm;
783 				}
784 			}
785 		}
786 	}
787 
788 	if (mdata->dev_comp->dma_ext)
789 		addr_bits = DMA_ADDR_EXT_BITS;
790 	else
791 		addr_bits = DMA_ADDR_DEF_BITS;
792 	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(addr_bits));
793 	if (ret)
794 		dev_notice(&pdev->dev, "SPI dma_set_mask(%d) failed, ret:%d\n",
795 			   addr_bits, ret);
796 
797 	return 0;
798 
799 err_disable_runtime_pm:
800 	pm_runtime_disable(&pdev->dev);
801 err_put_master:
802 	spi_master_put(master);
803 
804 	return ret;
805 }
806 
807 static int mtk_spi_remove(struct platform_device *pdev)
808 {
809 	struct spi_master *master = platform_get_drvdata(pdev);
810 	struct mtk_spi *mdata = spi_master_get_devdata(master);
811 
812 	pm_runtime_disable(&pdev->dev);
813 
814 	mtk_spi_reset(mdata);
815 
816 	return 0;
817 }
818 
819 #ifdef CONFIG_PM_SLEEP
820 static int mtk_spi_suspend(struct device *dev)
821 {
822 	int ret;
823 	struct spi_master *master = dev_get_drvdata(dev);
824 	struct mtk_spi *mdata = spi_master_get_devdata(master);
825 
826 	ret = spi_master_suspend(master);
827 	if (ret)
828 		return ret;
829 
830 	if (!pm_runtime_suspended(dev))
831 		clk_disable_unprepare(mdata->spi_clk);
832 
833 	return ret;
834 }
835 
836 static int mtk_spi_resume(struct device *dev)
837 {
838 	int ret;
839 	struct spi_master *master = dev_get_drvdata(dev);
840 	struct mtk_spi *mdata = spi_master_get_devdata(master);
841 
842 	if (!pm_runtime_suspended(dev)) {
843 		ret = clk_prepare_enable(mdata->spi_clk);
844 		if (ret < 0) {
845 			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
846 			return ret;
847 		}
848 	}
849 
850 	ret = spi_master_resume(master);
851 	if (ret < 0)
852 		clk_disable_unprepare(mdata->spi_clk);
853 
854 	return ret;
855 }
856 #endif /* CONFIG_PM_SLEEP */
857 
858 #ifdef CONFIG_PM
859 static int mtk_spi_runtime_suspend(struct device *dev)
860 {
861 	struct spi_master *master = dev_get_drvdata(dev);
862 	struct mtk_spi *mdata = spi_master_get_devdata(master);
863 
864 	clk_disable_unprepare(mdata->spi_clk);
865 
866 	return 0;
867 }
868 
869 static int mtk_spi_runtime_resume(struct device *dev)
870 {
871 	struct spi_master *master = dev_get_drvdata(dev);
872 	struct mtk_spi *mdata = spi_master_get_devdata(master);
873 	int ret;
874 
875 	ret = clk_prepare_enable(mdata->spi_clk);
876 	if (ret < 0) {
877 		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
878 		return ret;
879 	}
880 
881 	return 0;
882 }
883 #endif /* CONFIG_PM */
884 
885 static const struct dev_pm_ops mtk_spi_pm = {
886 	SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_suspend, mtk_spi_resume)
887 	SET_RUNTIME_PM_OPS(mtk_spi_runtime_suspend,
888 			   mtk_spi_runtime_resume, NULL)
889 };
890 
891 static struct platform_driver mtk_spi_driver = {
892 	.driver = {
893 		.name = "mtk-spi",
894 		.pm	= &mtk_spi_pm,
895 		.of_match_table = mtk_spi_of_match,
896 	},
897 	.probe = mtk_spi_probe,
898 	.remove = mtk_spi_remove,
899 };
900 
901 module_platform_driver(mtk_spi_driver);
902 
903 MODULE_DESCRIPTION("MTK SPI Controller driver");
904 MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
905 MODULE_LICENSE("GPL v2");
906 MODULE_ALIAS("platform:mtk-spi");
907