xref: /openbmc/linux/drivers/spi/spi-mt65xx.c (revision b4e18b29)
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_CS_HOLD_OFFSET    0
40 #define SPI_ADJUST_CFG0_CS_SETUP_OFFSET   16
41 
42 #define SPI_CFG1_CS_IDLE_OFFSET           0
43 #define SPI_CFG1_PACKET_LOOP_OFFSET       8
44 #define SPI_CFG1_PACKET_LENGTH_OFFSET     16
45 #define SPI_CFG1_GET_TICK_DLY_OFFSET      30
46 
47 #define SPI_CFG1_CS_IDLE_MASK             0xff
48 #define SPI_CFG1_PACKET_LOOP_MASK         0xff00
49 #define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
50 #define SPI_CFG2_SCK_HIGH_OFFSET          0
51 #define SPI_CFG2_SCK_LOW_OFFSET           16
52 
53 #define SPI_CMD_ACT                  BIT(0)
54 #define SPI_CMD_RESUME               BIT(1)
55 #define SPI_CMD_RST                  BIT(2)
56 #define SPI_CMD_PAUSE_EN             BIT(4)
57 #define SPI_CMD_DEASSERT             BIT(5)
58 #define SPI_CMD_SAMPLE_SEL           BIT(6)
59 #define SPI_CMD_CS_POL               BIT(7)
60 #define SPI_CMD_CPHA                 BIT(8)
61 #define SPI_CMD_CPOL                 BIT(9)
62 #define SPI_CMD_RX_DMA               BIT(10)
63 #define SPI_CMD_TX_DMA               BIT(11)
64 #define SPI_CMD_TXMSBF               BIT(12)
65 #define SPI_CMD_RXMSBF               BIT(13)
66 #define SPI_CMD_RX_ENDIAN            BIT(14)
67 #define SPI_CMD_TX_ENDIAN            BIT(15)
68 #define SPI_CMD_FINISH_IE            BIT(16)
69 #define SPI_CMD_PAUSE_IE             BIT(17)
70 
71 #define MT8173_SPI_MAX_PAD_SEL 3
72 
73 #define MTK_SPI_PAUSE_INT_STATUS 0x2
74 
75 #define MTK_SPI_IDLE 0
76 #define MTK_SPI_PAUSED 1
77 
78 #define MTK_SPI_MAX_FIFO_SIZE 32U
79 #define MTK_SPI_PACKET_SIZE 1024
80 #define MTK_SPI_32BITS_MASK  (0xffffffff)
81 
82 #define DMA_ADDR_EXT_BITS (36)
83 #define DMA_ADDR_DEF_BITS (32)
84 
85 struct mtk_spi_compatible {
86 	bool need_pad_sel;
87 	/* Must explicitly send dummy Tx bytes to do Rx only transfer */
88 	bool must_tx;
89 	/* some IC design adjust cfg register to enhance time accuracy */
90 	bool enhance_timing;
91 	/* some IC support DMA addr extension */
92 	bool dma_ext;
93 };
94 
95 struct mtk_spi {
96 	void __iomem *base;
97 	u32 state;
98 	int pad_num;
99 	u32 *pad_sel;
100 	struct clk *parent_clk, *sel_clk, *spi_clk;
101 	struct spi_transfer *cur_transfer;
102 	u32 xfer_len;
103 	u32 num_xfered;
104 	struct scatterlist *tx_sgl, *rx_sgl;
105 	u32 tx_sgl_len, rx_sgl_len;
106 	const struct mtk_spi_compatible *dev_comp;
107 };
108 
109 static const struct mtk_spi_compatible mtk_common_compat;
110 
111 static const struct mtk_spi_compatible mt2712_compat = {
112 	.must_tx = true,
113 };
114 
115 static const struct mtk_spi_compatible mt6765_compat = {
116 	.need_pad_sel = true,
117 	.must_tx = true,
118 	.enhance_timing = true,
119 	.dma_ext = true,
120 };
121 
122 static const struct mtk_spi_compatible mt7622_compat = {
123 	.must_tx = true,
124 	.enhance_timing = true,
125 };
126 
127 static const struct mtk_spi_compatible mt8173_compat = {
128 	.need_pad_sel = true,
129 	.must_tx = true,
130 };
131 
132 static const struct mtk_spi_compatible mt8183_compat = {
133 	.need_pad_sel = true,
134 	.must_tx = true,
135 	.enhance_timing = true,
136 };
137 
138 /*
139  * A piece of default chip info unless the platform
140  * supplies it.
141  */
142 static const struct mtk_chip_config mtk_default_chip_info = {
143 	.sample_sel = 0,
144 };
145 
146 static const struct of_device_id mtk_spi_of_match[] = {
147 	{ .compatible = "mediatek,mt2701-spi",
148 		.data = (void *)&mtk_common_compat,
149 	},
150 	{ .compatible = "mediatek,mt2712-spi",
151 		.data = (void *)&mt2712_compat,
152 	},
153 	{ .compatible = "mediatek,mt6589-spi",
154 		.data = (void *)&mtk_common_compat,
155 	},
156 	{ .compatible = "mediatek,mt6765-spi",
157 		.data = (void *)&mt6765_compat,
158 	},
159 	{ .compatible = "mediatek,mt7622-spi",
160 		.data = (void *)&mt7622_compat,
161 	},
162 	{ .compatible = "mediatek,mt7629-spi",
163 		.data = (void *)&mt7622_compat,
164 	},
165 	{ .compatible = "mediatek,mt8135-spi",
166 		.data = (void *)&mtk_common_compat,
167 	},
168 	{ .compatible = "mediatek,mt8173-spi",
169 		.data = (void *)&mt8173_compat,
170 	},
171 	{ .compatible = "mediatek,mt8183-spi",
172 		.data = (void *)&mt8183_compat,
173 	},
174 	{ .compatible = "mediatek,mt8192-spi",
175 		.data = (void *)&mt6765_compat,
176 	},
177 	{}
178 };
179 MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
180 
181 static void mtk_spi_reset(struct mtk_spi *mdata)
182 {
183 	u32 reg_val;
184 
185 	/* set the software reset bit in SPI_CMD_REG. */
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 	reg_val = readl(mdata->base + SPI_CMD_REG);
191 	reg_val &= ~SPI_CMD_RST;
192 	writel(reg_val, mdata->base + SPI_CMD_REG);
193 }
194 
195 static int mtk_spi_prepare_message(struct spi_master *master,
196 				   struct spi_message *msg)
197 {
198 	u16 cpha, cpol;
199 	u32 reg_val;
200 	struct spi_device *spi = msg->spi;
201 	struct mtk_chip_config *chip_config = spi->controller_data;
202 	struct mtk_spi *mdata = spi_master_get_devdata(master);
203 
204 	cpha = spi->mode & SPI_CPHA ? 1 : 0;
205 	cpol = spi->mode & SPI_CPOL ? 1 : 0;
206 
207 	reg_val = readl(mdata->base + SPI_CMD_REG);
208 	if (cpha)
209 		reg_val |= SPI_CMD_CPHA;
210 	else
211 		reg_val &= ~SPI_CMD_CPHA;
212 	if (cpol)
213 		reg_val |= SPI_CMD_CPOL;
214 	else
215 		reg_val &= ~SPI_CMD_CPOL;
216 
217 	/* set the mlsbx and mlsbtx */
218 	if (spi->mode & SPI_LSB_FIRST) {
219 		reg_val &= ~SPI_CMD_TXMSBF;
220 		reg_val &= ~SPI_CMD_RXMSBF;
221 	} else {
222 		reg_val |= SPI_CMD_TXMSBF;
223 		reg_val |= SPI_CMD_RXMSBF;
224 	}
225 
226 	/* set the tx/rx endian */
227 #ifdef __LITTLE_ENDIAN
228 	reg_val &= ~SPI_CMD_TX_ENDIAN;
229 	reg_val &= ~SPI_CMD_RX_ENDIAN;
230 #else
231 	reg_val |= SPI_CMD_TX_ENDIAN;
232 	reg_val |= SPI_CMD_RX_ENDIAN;
233 #endif
234 
235 	if (mdata->dev_comp->enhance_timing) {
236 		/* set CS polarity */
237 		if (spi->mode & SPI_CS_HIGH)
238 			reg_val |= SPI_CMD_CS_POL;
239 		else
240 			reg_val &= ~SPI_CMD_CS_POL;
241 
242 		if (chip_config->sample_sel)
243 			reg_val |= SPI_CMD_SAMPLE_SEL;
244 		else
245 			reg_val &= ~SPI_CMD_SAMPLE_SEL;
246 	}
247 
248 	/* set finish and pause interrupt always enable */
249 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;
250 
251 	/* disable dma mode */
252 	reg_val &= ~(SPI_CMD_TX_DMA | SPI_CMD_RX_DMA);
253 
254 	/* disable deassert mode */
255 	reg_val &= ~SPI_CMD_DEASSERT;
256 
257 	writel(reg_val, mdata->base + SPI_CMD_REG);
258 
259 	/* pad select */
260 	if (mdata->dev_comp->need_pad_sel)
261 		writel(mdata->pad_sel[spi->chip_select],
262 		       mdata->base + SPI_PAD_SEL_REG);
263 
264 	return 0;
265 }
266 
267 static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
268 {
269 	u32 reg_val;
270 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
271 
272 	if (spi->mode & SPI_CS_HIGH)
273 		enable = !enable;
274 
275 	reg_val = readl(mdata->base + SPI_CMD_REG);
276 	if (!enable) {
277 		reg_val |= SPI_CMD_PAUSE_EN;
278 		writel(reg_val, mdata->base + SPI_CMD_REG);
279 	} else {
280 		reg_val &= ~SPI_CMD_PAUSE_EN;
281 		writel(reg_val, mdata->base + SPI_CMD_REG);
282 		mdata->state = MTK_SPI_IDLE;
283 		mtk_spi_reset(mdata);
284 	}
285 }
286 
287 static void mtk_spi_prepare_transfer(struct spi_master *master,
288 				     struct spi_transfer *xfer)
289 {
290 	u32 spi_clk_hz, div, sck_time, cs_time, reg_val;
291 	struct mtk_spi *mdata = spi_master_get_devdata(master);
292 
293 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
294 	if (xfer->speed_hz < spi_clk_hz / 2)
295 		div = DIV_ROUND_UP(spi_clk_hz, xfer->speed_hz);
296 	else
297 		div = 1;
298 
299 	sck_time = (div + 1) / 2;
300 	cs_time = sck_time * 2;
301 
302 	if (mdata->dev_comp->enhance_timing) {
303 		reg_val = (((sck_time - 1) & 0xffff)
304 			   << SPI_CFG2_SCK_HIGH_OFFSET);
305 		reg_val |= (((sck_time - 1) & 0xffff)
306 			   << SPI_CFG2_SCK_LOW_OFFSET);
307 		writel(reg_val, mdata->base + SPI_CFG2_REG);
308 		reg_val = (((cs_time - 1) & 0xffff)
309 			   << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
310 		reg_val |= (((cs_time - 1) & 0xffff)
311 			   << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
312 		writel(reg_val, mdata->base + SPI_CFG0_REG);
313 	} else {
314 		reg_val = (((sck_time - 1) & 0xff)
315 			   << SPI_CFG0_SCK_HIGH_OFFSET);
316 		reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
317 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
318 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
319 		writel(reg_val, mdata->base + SPI_CFG0_REG);
320 	}
321 
322 	reg_val = readl(mdata->base + SPI_CFG1_REG);
323 	reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
324 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
325 	writel(reg_val, mdata->base + SPI_CFG1_REG);
326 }
327 
328 static void mtk_spi_setup_packet(struct spi_master *master)
329 {
330 	u32 packet_size, packet_loop, reg_val;
331 	struct mtk_spi *mdata = spi_master_get_devdata(master);
332 
333 	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
334 	packet_loop = mdata->xfer_len / packet_size;
335 
336 	reg_val = readl(mdata->base + SPI_CFG1_REG);
337 	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
338 	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
339 	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
340 	writel(reg_val, mdata->base + SPI_CFG1_REG);
341 }
342 
343 static void mtk_spi_enable_transfer(struct spi_master *master)
344 {
345 	u32 cmd;
346 	struct mtk_spi *mdata = spi_master_get_devdata(master);
347 
348 	cmd = readl(mdata->base + SPI_CMD_REG);
349 	if (mdata->state == MTK_SPI_IDLE)
350 		cmd |= SPI_CMD_ACT;
351 	else
352 		cmd |= SPI_CMD_RESUME;
353 	writel(cmd, mdata->base + SPI_CMD_REG);
354 }
355 
356 static int mtk_spi_get_mult_delta(u32 xfer_len)
357 {
358 	u32 mult_delta;
359 
360 	if (xfer_len > MTK_SPI_PACKET_SIZE)
361 		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
362 	else
363 		mult_delta = 0;
364 
365 	return mult_delta;
366 }
367 
368 static void mtk_spi_update_mdata_len(struct spi_master *master)
369 {
370 	int mult_delta;
371 	struct mtk_spi *mdata = spi_master_get_devdata(master);
372 
373 	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
374 		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
375 			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
376 			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
377 			mdata->rx_sgl_len = mult_delta;
378 			mdata->tx_sgl_len -= mdata->xfer_len;
379 		} else {
380 			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
381 			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
382 			mdata->tx_sgl_len = mult_delta;
383 			mdata->rx_sgl_len -= mdata->xfer_len;
384 		}
385 	} else if (mdata->tx_sgl_len) {
386 		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
387 		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
388 		mdata->tx_sgl_len = mult_delta;
389 	} else if (mdata->rx_sgl_len) {
390 		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
391 		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
392 		mdata->rx_sgl_len = mult_delta;
393 	}
394 }
395 
396 static void mtk_spi_setup_dma_addr(struct spi_master *master,
397 				   struct spi_transfer *xfer)
398 {
399 	struct mtk_spi *mdata = spi_master_get_devdata(master);
400 
401 	if (mdata->tx_sgl) {
402 		writel((u32)(xfer->tx_dma & MTK_SPI_32BITS_MASK),
403 		       mdata->base + SPI_TX_SRC_REG);
404 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
405 		if (mdata->dev_comp->dma_ext)
406 			writel((u32)(xfer->tx_dma >> 32),
407 			       mdata->base + SPI_TX_SRC_REG_64);
408 #endif
409 	}
410 
411 	if (mdata->rx_sgl) {
412 		writel((u32)(xfer->rx_dma & MTK_SPI_32BITS_MASK),
413 		       mdata->base + SPI_RX_DST_REG);
414 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
415 		if (mdata->dev_comp->dma_ext)
416 			writel((u32)(xfer->rx_dma >> 32),
417 			       mdata->base + SPI_RX_DST_REG_64);
418 #endif
419 	}
420 }
421 
422 static int mtk_spi_fifo_transfer(struct spi_master *master,
423 				 struct spi_device *spi,
424 				 struct spi_transfer *xfer)
425 {
426 	int cnt, remainder;
427 	u32 reg_val;
428 	struct mtk_spi *mdata = spi_master_get_devdata(master);
429 
430 	mdata->cur_transfer = xfer;
431 	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
432 	mdata->num_xfered = 0;
433 	mtk_spi_prepare_transfer(master, xfer);
434 	mtk_spi_setup_packet(master);
435 
436 	cnt = xfer->len / 4;
437 	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
438 
439 	remainder = xfer->len % 4;
440 	if (remainder > 0) {
441 		reg_val = 0;
442 		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
443 		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
444 	}
445 
446 	mtk_spi_enable_transfer(master);
447 
448 	return 1;
449 }
450 
451 static int mtk_spi_dma_transfer(struct spi_master *master,
452 				struct spi_device *spi,
453 				struct spi_transfer *xfer)
454 {
455 	int cmd;
456 	struct mtk_spi *mdata = spi_master_get_devdata(master);
457 
458 	mdata->tx_sgl = NULL;
459 	mdata->rx_sgl = NULL;
460 	mdata->tx_sgl_len = 0;
461 	mdata->rx_sgl_len = 0;
462 	mdata->cur_transfer = xfer;
463 	mdata->num_xfered = 0;
464 
465 	mtk_spi_prepare_transfer(master, xfer);
466 
467 	cmd = readl(mdata->base + SPI_CMD_REG);
468 	if (xfer->tx_buf)
469 		cmd |= SPI_CMD_TX_DMA;
470 	if (xfer->rx_buf)
471 		cmd |= SPI_CMD_RX_DMA;
472 	writel(cmd, mdata->base + SPI_CMD_REG);
473 
474 	if (xfer->tx_buf)
475 		mdata->tx_sgl = xfer->tx_sg.sgl;
476 	if (xfer->rx_buf)
477 		mdata->rx_sgl = xfer->rx_sg.sgl;
478 
479 	if (mdata->tx_sgl) {
480 		xfer->tx_dma = sg_dma_address(mdata->tx_sgl);
481 		mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
482 	}
483 	if (mdata->rx_sgl) {
484 		xfer->rx_dma = sg_dma_address(mdata->rx_sgl);
485 		mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
486 	}
487 
488 	mtk_spi_update_mdata_len(master);
489 	mtk_spi_setup_packet(master);
490 	mtk_spi_setup_dma_addr(master, xfer);
491 	mtk_spi_enable_transfer(master);
492 
493 	return 1;
494 }
495 
496 static int mtk_spi_transfer_one(struct spi_master *master,
497 				struct spi_device *spi,
498 				struct spi_transfer *xfer)
499 {
500 	if (master->can_dma(master, spi, xfer))
501 		return mtk_spi_dma_transfer(master, spi, xfer);
502 	else
503 		return mtk_spi_fifo_transfer(master, spi, xfer);
504 }
505 
506 static bool mtk_spi_can_dma(struct spi_master *master,
507 			    struct spi_device *spi,
508 			    struct spi_transfer *xfer)
509 {
510 	/* Buffers for DMA transactions must be 4-byte aligned */
511 	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
512 		(unsigned long)xfer->tx_buf % 4 == 0 &&
513 		(unsigned long)xfer->rx_buf % 4 == 0);
514 }
515 
516 static int mtk_spi_setup(struct spi_device *spi)
517 {
518 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
519 
520 	if (!spi->controller_data)
521 		spi->controller_data = (void *)&mtk_default_chip_info;
522 
523 	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
524 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
525 
526 	return 0;
527 }
528 
529 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
530 {
531 	u32 cmd, reg_val, cnt, remainder, len;
532 	struct spi_master *master = dev_id;
533 	struct mtk_spi *mdata = spi_master_get_devdata(master);
534 	struct spi_transfer *trans = mdata->cur_transfer;
535 
536 	reg_val = readl(mdata->base + SPI_STATUS0_REG);
537 	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
538 		mdata->state = MTK_SPI_PAUSED;
539 	else
540 		mdata->state = MTK_SPI_IDLE;
541 
542 	if (!master->can_dma(master, master->cur_msg->spi, trans)) {
543 		if (trans->rx_buf) {
544 			cnt = mdata->xfer_len / 4;
545 			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
546 				     trans->rx_buf + mdata->num_xfered, cnt);
547 			remainder = mdata->xfer_len % 4;
548 			if (remainder > 0) {
549 				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
550 				memcpy(trans->rx_buf +
551 					mdata->num_xfered +
552 					(cnt * 4),
553 					&reg_val,
554 					remainder);
555 			}
556 		}
557 
558 		mdata->num_xfered += mdata->xfer_len;
559 		if (mdata->num_xfered == trans->len) {
560 			spi_finalize_current_transfer(master);
561 			return IRQ_HANDLED;
562 		}
563 
564 		len = trans->len - mdata->num_xfered;
565 		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, len);
566 		mtk_spi_setup_packet(master);
567 
568 		cnt = mdata->xfer_len / 4;
569 		iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
570 				trans->tx_buf + mdata->num_xfered, cnt);
571 
572 		remainder = mdata->xfer_len % 4;
573 		if (remainder > 0) {
574 			reg_val = 0;
575 			memcpy(&reg_val,
576 				trans->tx_buf + (cnt * 4) + mdata->num_xfered,
577 				remainder);
578 			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
579 		}
580 
581 		mtk_spi_enable_transfer(master);
582 
583 		return IRQ_HANDLED;
584 	}
585 
586 	if (mdata->tx_sgl)
587 		trans->tx_dma += mdata->xfer_len;
588 	if (mdata->rx_sgl)
589 		trans->rx_dma += mdata->xfer_len;
590 
591 	if (mdata->tx_sgl && (mdata->tx_sgl_len == 0)) {
592 		mdata->tx_sgl = sg_next(mdata->tx_sgl);
593 		if (mdata->tx_sgl) {
594 			trans->tx_dma = sg_dma_address(mdata->tx_sgl);
595 			mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
596 		}
597 	}
598 	if (mdata->rx_sgl && (mdata->rx_sgl_len == 0)) {
599 		mdata->rx_sgl = sg_next(mdata->rx_sgl);
600 		if (mdata->rx_sgl) {
601 			trans->rx_dma = sg_dma_address(mdata->rx_sgl);
602 			mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
603 		}
604 	}
605 
606 	if (!mdata->tx_sgl && !mdata->rx_sgl) {
607 		/* spi disable dma */
608 		cmd = readl(mdata->base + SPI_CMD_REG);
609 		cmd &= ~SPI_CMD_TX_DMA;
610 		cmd &= ~SPI_CMD_RX_DMA;
611 		writel(cmd, mdata->base + SPI_CMD_REG);
612 
613 		spi_finalize_current_transfer(master);
614 		return IRQ_HANDLED;
615 	}
616 
617 	mtk_spi_update_mdata_len(master);
618 	mtk_spi_setup_packet(master);
619 	mtk_spi_setup_dma_addr(master, trans);
620 	mtk_spi_enable_transfer(master);
621 
622 	return IRQ_HANDLED;
623 }
624 
625 static int mtk_spi_probe(struct platform_device *pdev)
626 {
627 	struct spi_master *master;
628 	struct mtk_spi *mdata;
629 	const struct of_device_id *of_id;
630 	int i, irq, ret, addr_bits;
631 
632 	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
633 	if (!master) {
634 		dev_err(&pdev->dev, "failed to alloc spi master\n");
635 		return -ENOMEM;
636 	}
637 
638 	master->auto_runtime_pm = true;
639 	master->dev.of_node = pdev->dev.of_node;
640 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
641 
642 	master->set_cs = mtk_spi_set_cs;
643 	master->prepare_message = mtk_spi_prepare_message;
644 	master->transfer_one = mtk_spi_transfer_one;
645 	master->can_dma = mtk_spi_can_dma;
646 	master->setup = mtk_spi_setup;
647 
648 	of_id = of_match_node(mtk_spi_of_match, pdev->dev.of_node);
649 	if (!of_id) {
650 		dev_err(&pdev->dev, "failed to probe of_node\n");
651 		ret = -EINVAL;
652 		goto err_put_master;
653 	}
654 
655 	mdata = spi_master_get_devdata(master);
656 	mdata->dev_comp = of_id->data;
657 
658 	if (mdata->dev_comp->enhance_timing)
659 		master->mode_bits |= SPI_CS_HIGH;
660 
661 	if (mdata->dev_comp->must_tx)
662 		master->flags = SPI_MASTER_MUST_TX;
663 
664 	if (mdata->dev_comp->need_pad_sel) {
665 		mdata->pad_num = of_property_count_u32_elems(
666 			pdev->dev.of_node,
667 			"mediatek,pad-select");
668 		if (mdata->pad_num < 0) {
669 			dev_err(&pdev->dev,
670 				"No 'mediatek,pad-select' property\n");
671 			ret = -EINVAL;
672 			goto err_put_master;
673 		}
674 
675 		mdata->pad_sel = devm_kmalloc_array(&pdev->dev, mdata->pad_num,
676 						    sizeof(u32), GFP_KERNEL);
677 		if (!mdata->pad_sel) {
678 			ret = -ENOMEM;
679 			goto err_put_master;
680 		}
681 
682 		for (i = 0; i < mdata->pad_num; i++) {
683 			of_property_read_u32_index(pdev->dev.of_node,
684 						   "mediatek,pad-select",
685 						   i, &mdata->pad_sel[i]);
686 			if (mdata->pad_sel[i] > MT8173_SPI_MAX_PAD_SEL) {
687 				dev_err(&pdev->dev, "wrong pad-sel[%d]: %u\n",
688 					i, mdata->pad_sel[i]);
689 				ret = -EINVAL;
690 				goto err_put_master;
691 			}
692 		}
693 	}
694 
695 	platform_set_drvdata(pdev, master);
696 	mdata->base = devm_platform_ioremap_resource(pdev, 0);
697 	if (IS_ERR(mdata->base)) {
698 		ret = PTR_ERR(mdata->base);
699 		goto err_put_master;
700 	}
701 
702 	irq = platform_get_irq(pdev, 0);
703 	if (irq < 0) {
704 		ret = irq;
705 		goto err_put_master;
706 	}
707 
708 	if (!pdev->dev.dma_mask)
709 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
710 
711 	ret = devm_request_irq(&pdev->dev, irq, mtk_spi_interrupt,
712 			       IRQF_TRIGGER_NONE, dev_name(&pdev->dev), master);
713 	if (ret) {
714 		dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
715 		goto err_put_master;
716 	}
717 
718 	mdata->parent_clk = devm_clk_get(&pdev->dev, "parent-clk");
719 	if (IS_ERR(mdata->parent_clk)) {
720 		ret = PTR_ERR(mdata->parent_clk);
721 		dev_err(&pdev->dev, "failed to get parent-clk: %d\n", ret);
722 		goto err_put_master;
723 	}
724 
725 	mdata->sel_clk = devm_clk_get(&pdev->dev, "sel-clk");
726 	if (IS_ERR(mdata->sel_clk)) {
727 		ret = PTR_ERR(mdata->sel_clk);
728 		dev_err(&pdev->dev, "failed to get sel-clk: %d\n", ret);
729 		goto err_put_master;
730 	}
731 
732 	mdata->spi_clk = devm_clk_get(&pdev->dev, "spi-clk");
733 	if (IS_ERR(mdata->spi_clk)) {
734 		ret = PTR_ERR(mdata->spi_clk);
735 		dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
736 		goto err_put_master;
737 	}
738 
739 	ret = clk_prepare_enable(mdata->spi_clk);
740 	if (ret < 0) {
741 		dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
742 		goto err_put_master;
743 	}
744 
745 	ret = clk_set_parent(mdata->sel_clk, mdata->parent_clk);
746 	if (ret < 0) {
747 		dev_err(&pdev->dev, "failed to clk_set_parent (%d)\n", ret);
748 		clk_disable_unprepare(mdata->spi_clk);
749 		goto err_put_master;
750 	}
751 
752 	clk_disable_unprepare(mdata->spi_clk);
753 
754 	pm_runtime_enable(&pdev->dev);
755 
756 	ret = devm_spi_register_master(&pdev->dev, master);
757 	if (ret) {
758 		dev_err(&pdev->dev, "failed to register master (%d)\n", ret);
759 		goto err_disable_runtime_pm;
760 	}
761 
762 	if (mdata->dev_comp->need_pad_sel) {
763 		if (mdata->pad_num != master->num_chipselect) {
764 			dev_err(&pdev->dev,
765 				"pad_num does not match num_chipselect(%d != %d)\n",
766 				mdata->pad_num, master->num_chipselect);
767 			ret = -EINVAL;
768 			goto err_disable_runtime_pm;
769 		}
770 
771 		if (!master->cs_gpios && master->num_chipselect > 1) {
772 			dev_err(&pdev->dev,
773 				"cs_gpios not specified and num_chipselect > 1\n");
774 			ret = -EINVAL;
775 			goto err_disable_runtime_pm;
776 		}
777 
778 		if (master->cs_gpios) {
779 			for (i = 0; i < master->num_chipselect; i++) {
780 				ret = devm_gpio_request(&pdev->dev,
781 							master->cs_gpios[i],
782 							dev_name(&pdev->dev));
783 				if (ret) {
784 					dev_err(&pdev->dev,
785 						"can't get CS GPIO %i\n", i);
786 					goto err_disable_runtime_pm;
787 				}
788 			}
789 		}
790 	}
791 
792 	if (mdata->dev_comp->dma_ext)
793 		addr_bits = DMA_ADDR_EXT_BITS;
794 	else
795 		addr_bits = DMA_ADDR_DEF_BITS;
796 	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(addr_bits));
797 	if (ret)
798 		dev_notice(&pdev->dev, "SPI dma_set_mask(%d) failed, ret:%d\n",
799 			   addr_bits, ret);
800 
801 	return 0;
802 
803 err_disable_runtime_pm:
804 	pm_runtime_disable(&pdev->dev);
805 err_put_master:
806 	spi_master_put(master);
807 
808 	return ret;
809 }
810 
811 static int mtk_spi_remove(struct platform_device *pdev)
812 {
813 	struct spi_master *master = platform_get_drvdata(pdev);
814 	struct mtk_spi *mdata = spi_master_get_devdata(master);
815 
816 	pm_runtime_disable(&pdev->dev);
817 
818 	mtk_spi_reset(mdata);
819 
820 	return 0;
821 }
822 
823 #ifdef CONFIG_PM_SLEEP
824 static int mtk_spi_suspend(struct device *dev)
825 {
826 	int ret;
827 	struct spi_master *master = dev_get_drvdata(dev);
828 	struct mtk_spi *mdata = spi_master_get_devdata(master);
829 
830 	ret = spi_master_suspend(master);
831 	if (ret)
832 		return ret;
833 
834 	if (!pm_runtime_suspended(dev))
835 		clk_disable_unprepare(mdata->spi_clk);
836 
837 	return ret;
838 }
839 
840 static int mtk_spi_resume(struct device *dev)
841 {
842 	int ret;
843 	struct spi_master *master = dev_get_drvdata(dev);
844 	struct mtk_spi *mdata = spi_master_get_devdata(master);
845 
846 	if (!pm_runtime_suspended(dev)) {
847 		ret = clk_prepare_enable(mdata->spi_clk);
848 		if (ret < 0) {
849 			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
850 			return ret;
851 		}
852 	}
853 
854 	ret = spi_master_resume(master);
855 	if (ret < 0)
856 		clk_disable_unprepare(mdata->spi_clk);
857 
858 	return ret;
859 }
860 #endif /* CONFIG_PM_SLEEP */
861 
862 #ifdef CONFIG_PM
863 static int mtk_spi_runtime_suspend(struct device *dev)
864 {
865 	struct spi_master *master = dev_get_drvdata(dev);
866 	struct mtk_spi *mdata = spi_master_get_devdata(master);
867 
868 	clk_disable_unprepare(mdata->spi_clk);
869 
870 	return 0;
871 }
872 
873 static int mtk_spi_runtime_resume(struct device *dev)
874 {
875 	struct spi_master *master = dev_get_drvdata(dev);
876 	struct mtk_spi *mdata = spi_master_get_devdata(master);
877 	int ret;
878 
879 	ret = clk_prepare_enable(mdata->spi_clk);
880 	if (ret < 0) {
881 		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
882 		return ret;
883 	}
884 
885 	return 0;
886 }
887 #endif /* CONFIG_PM */
888 
889 static const struct dev_pm_ops mtk_spi_pm = {
890 	SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_suspend, mtk_spi_resume)
891 	SET_RUNTIME_PM_OPS(mtk_spi_runtime_suspend,
892 			   mtk_spi_runtime_resume, NULL)
893 };
894 
895 static struct platform_driver mtk_spi_driver = {
896 	.driver = {
897 		.name = "mtk-spi",
898 		.pm	= &mtk_spi_pm,
899 		.of_match_table = mtk_spi_of_match,
900 	},
901 	.probe = mtk_spi_probe,
902 	.remove = mtk_spi_remove,
903 };
904 
905 module_platform_driver(mtk_spi_driver);
906 
907 MODULE_DESCRIPTION("MTK SPI Controller driver");
908 MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
909 MODULE_LICENSE("GPL v2");
910 MODULE_ALIAS("platform:mtk-spi");
911