xref: /openbmc/linux/drivers/spi/spi-mt65xx.c (revision b60a5b8d)
1 /*
2  * Copyright (c) 2015 MediaTek Inc.
3  * Author: Leilk Liu <leilk.liu@mediatek.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/clk.h>
16 #include <linux/device.h>
17 #include <linux/err.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/ioport.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_gpio.h>
24 #include <linux/platform_device.h>
25 #include <linux/platform_data/spi-mt65xx.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/spi/spi.h>
28 
29 #define SPI_CFG0_REG                      0x0000
30 #define SPI_CFG1_REG                      0x0004
31 #define SPI_TX_SRC_REG                    0x0008
32 #define SPI_RX_DST_REG                    0x000c
33 #define SPI_TX_DATA_REG                   0x0010
34 #define SPI_RX_DATA_REG                   0x0014
35 #define SPI_CMD_REG                       0x0018
36 #define SPI_STATUS0_REG                   0x001c
37 #define SPI_PAD_SEL_REG                   0x0024
38 #define SPI_CFG2_REG                      0x0028
39 
40 #define SPI_CFG0_SCK_HIGH_OFFSET          0
41 #define SPI_CFG0_SCK_LOW_OFFSET           8
42 #define SPI_CFG0_CS_HOLD_OFFSET           16
43 #define SPI_CFG0_CS_SETUP_OFFSET          24
44 #define SPI_ADJUST_CFG0_SCK_LOW_OFFSET    16
45 #define SPI_ADJUST_CFG0_CS_HOLD_OFFSET    0
46 #define SPI_ADJUST_CFG0_CS_SETUP_OFFSET   16
47 
48 #define SPI_CFG1_CS_IDLE_OFFSET           0
49 #define SPI_CFG1_PACKET_LOOP_OFFSET       8
50 #define SPI_CFG1_PACKET_LENGTH_OFFSET     16
51 #define SPI_CFG1_GET_TICK_DLY_OFFSET      30
52 
53 #define SPI_CFG1_CS_IDLE_MASK             0xff
54 #define SPI_CFG1_PACKET_LOOP_MASK         0xff00
55 #define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
56 
57 #define SPI_CMD_ACT                  BIT(0)
58 #define SPI_CMD_RESUME               BIT(1)
59 #define SPI_CMD_RST                  BIT(2)
60 #define SPI_CMD_PAUSE_EN             BIT(4)
61 #define SPI_CMD_DEASSERT             BIT(5)
62 #define SPI_CMD_SAMPLE_SEL           BIT(6)
63 #define SPI_CMD_CS_POL               BIT(7)
64 #define SPI_CMD_CPHA                 BIT(8)
65 #define SPI_CMD_CPOL                 BIT(9)
66 #define SPI_CMD_RX_DMA               BIT(10)
67 #define SPI_CMD_TX_DMA               BIT(11)
68 #define SPI_CMD_TXMSBF               BIT(12)
69 #define SPI_CMD_RXMSBF               BIT(13)
70 #define SPI_CMD_RX_ENDIAN            BIT(14)
71 #define SPI_CMD_TX_ENDIAN            BIT(15)
72 #define SPI_CMD_FINISH_IE            BIT(16)
73 #define SPI_CMD_PAUSE_IE             BIT(17)
74 
75 #define MT8173_SPI_MAX_PAD_SEL 3
76 
77 #define MTK_SPI_PAUSE_INT_STATUS 0x2
78 
79 #define MTK_SPI_IDLE 0
80 #define MTK_SPI_PAUSED 1
81 
82 #define MTK_SPI_MAX_FIFO_SIZE 32U
83 #define MTK_SPI_PACKET_SIZE 1024
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 };
92 
93 struct mtk_spi {
94 	void __iomem *base;
95 	u32 state;
96 	int pad_num;
97 	u32 *pad_sel;
98 	struct clk *parent_clk, *sel_clk, *spi_clk;
99 	struct spi_transfer *cur_transfer;
100 	u32 xfer_len;
101 	u32 num_xfered;
102 	struct scatterlist *tx_sgl, *rx_sgl;
103 	u32 tx_sgl_len, rx_sgl_len;
104 	const struct mtk_spi_compatible *dev_comp;
105 };
106 
107 static const struct mtk_spi_compatible mtk_common_compat;
108 
109 static const struct mtk_spi_compatible mt2712_compat = {
110 	.must_tx = true,
111 };
112 
113 static const struct mtk_spi_compatible mt7622_compat = {
114 	.must_tx = true,
115 	.enhance_timing = true,
116 };
117 
118 static const struct mtk_spi_compatible mt8173_compat = {
119 	.need_pad_sel = true,
120 	.must_tx = true,
121 };
122 
123 static const struct mtk_spi_compatible mt8183_compat = {
124 	.need_pad_sel = true,
125 	.must_tx = true,
126 	.enhance_timing = true,
127 };
128 
129 /*
130  * A piece of default chip info unless the platform
131  * supplies it.
132  */
133 static const struct mtk_chip_config mtk_default_chip_info = {
134 	.rx_mlsb = 1,
135 	.tx_mlsb = 1,
136 	.cs_pol = 0,
137 	.sample_sel = 0,
138 };
139 
140 static const struct of_device_id mtk_spi_of_match[] = {
141 	{ .compatible = "mediatek,mt2701-spi",
142 		.data = (void *)&mtk_common_compat,
143 	},
144 	{ .compatible = "mediatek,mt2712-spi",
145 		.data = (void *)&mt2712_compat,
146 	},
147 	{ .compatible = "mediatek,mt6589-spi",
148 		.data = (void *)&mtk_common_compat,
149 	},
150 	{ .compatible = "mediatek,mt7622-spi",
151 		.data = (void *)&mt7622_compat,
152 	},
153 	{ .compatible = "mediatek,mt7629-spi",
154 		.data = (void *)&mt7622_compat,
155 	},
156 	{ .compatible = "mediatek,mt8135-spi",
157 		.data = (void *)&mtk_common_compat,
158 	},
159 	{ .compatible = "mediatek,mt8173-spi",
160 		.data = (void *)&mt8173_compat,
161 	},
162 	{ .compatible = "mediatek,mt8183-spi",
163 		.data = (void *)&mt8183_compat,
164 	},
165 	{}
166 };
167 MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
168 
169 static void mtk_spi_reset(struct mtk_spi *mdata)
170 {
171 	u32 reg_val;
172 
173 	/* set the software reset bit in SPI_CMD_REG. */
174 	reg_val = readl(mdata->base + SPI_CMD_REG);
175 	reg_val |= SPI_CMD_RST;
176 	writel(reg_val, mdata->base + SPI_CMD_REG);
177 
178 	reg_val = readl(mdata->base + SPI_CMD_REG);
179 	reg_val &= ~SPI_CMD_RST;
180 	writel(reg_val, mdata->base + SPI_CMD_REG);
181 }
182 
183 static int mtk_spi_prepare_message(struct spi_master *master,
184 				   struct spi_message *msg)
185 {
186 	u16 cpha, cpol;
187 	u32 reg_val;
188 	struct spi_device *spi = msg->spi;
189 	struct mtk_chip_config *chip_config = spi->controller_data;
190 	struct mtk_spi *mdata = spi_master_get_devdata(master);
191 
192 	cpha = spi->mode & SPI_CPHA ? 1 : 0;
193 	cpol = spi->mode & SPI_CPOL ? 1 : 0;
194 
195 	reg_val = readl(mdata->base + SPI_CMD_REG);
196 	if (cpha)
197 		reg_val |= SPI_CMD_CPHA;
198 	else
199 		reg_val &= ~SPI_CMD_CPHA;
200 	if (cpol)
201 		reg_val |= SPI_CMD_CPOL;
202 	else
203 		reg_val &= ~SPI_CMD_CPOL;
204 
205 	/* set the mlsbx and mlsbtx */
206 	if (chip_config->tx_mlsb)
207 		reg_val |= SPI_CMD_TXMSBF;
208 	else
209 		reg_val &= ~SPI_CMD_TXMSBF;
210 	if (chip_config->rx_mlsb)
211 		reg_val |= SPI_CMD_RXMSBF;
212 	else
213 		reg_val &= ~SPI_CMD_RXMSBF;
214 
215 	/* set the tx/rx endian */
216 #ifdef __LITTLE_ENDIAN
217 	reg_val &= ~SPI_CMD_TX_ENDIAN;
218 	reg_val &= ~SPI_CMD_RX_ENDIAN;
219 #else
220 	reg_val |= SPI_CMD_TX_ENDIAN;
221 	reg_val |= SPI_CMD_RX_ENDIAN;
222 #endif
223 
224 	if (mdata->dev_comp->enhance_timing) {
225 		if (chip_config->cs_pol)
226 			reg_val |= SPI_CMD_CS_POL;
227 		else
228 			reg_val &= ~SPI_CMD_CS_POL;
229 		if (chip_config->sample_sel)
230 			reg_val |= SPI_CMD_SAMPLE_SEL;
231 		else
232 			reg_val &= ~SPI_CMD_SAMPLE_SEL;
233 	}
234 
235 	/* set finish and pause interrupt always enable */
236 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;
237 
238 	/* disable dma mode */
239 	reg_val &= ~(SPI_CMD_TX_DMA | SPI_CMD_RX_DMA);
240 
241 	/* disable deassert mode */
242 	reg_val &= ~SPI_CMD_DEASSERT;
243 
244 	writel(reg_val, mdata->base + SPI_CMD_REG);
245 
246 	/* pad select */
247 	if (mdata->dev_comp->need_pad_sel)
248 		writel(mdata->pad_sel[spi->chip_select],
249 		       mdata->base + SPI_PAD_SEL_REG);
250 
251 	return 0;
252 }
253 
254 static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
255 {
256 	u32 reg_val;
257 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
258 
259 	reg_val = readl(mdata->base + SPI_CMD_REG);
260 	if (!enable) {
261 		reg_val |= SPI_CMD_PAUSE_EN;
262 		writel(reg_val, mdata->base + SPI_CMD_REG);
263 	} else {
264 		reg_val &= ~SPI_CMD_PAUSE_EN;
265 		writel(reg_val, mdata->base + SPI_CMD_REG);
266 		mdata->state = MTK_SPI_IDLE;
267 		mtk_spi_reset(mdata);
268 	}
269 }
270 
271 static void mtk_spi_prepare_transfer(struct spi_master *master,
272 				     struct spi_transfer *xfer)
273 {
274 	u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0;
275 	struct mtk_spi *mdata = spi_master_get_devdata(master);
276 
277 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
278 	if (xfer->speed_hz < spi_clk_hz / 2)
279 		div = DIV_ROUND_UP(spi_clk_hz, xfer->speed_hz);
280 	else
281 		div = 1;
282 
283 	sck_time = (div + 1) / 2;
284 	cs_time = sck_time * 2;
285 
286 	if (mdata->dev_comp->enhance_timing) {
287 		reg_val |= (((sck_time - 1) & 0xffff)
288 			   << SPI_CFG0_SCK_HIGH_OFFSET);
289 		reg_val |= (((sck_time - 1) & 0xffff)
290 			   << SPI_ADJUST_CFG0_SCK_LOW_OFFSET);
291 		writel(reg_val, mdata->base + SPI_CFG2_REG);
292 		reg_val |= (((cs_time - 1) & 0xffff)
293 			   << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
294 		reg_val |= (((cs_time - 1) & 0xffff)
295 			   << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
296 		writel(reg_val, mdata->base + SPI_CFG0_REG);
297 	} else {
298 		reg_val |= (((sck_time - 1) & 0xff)
299 			   << SPI_CFG0_SCK_HIGH_OFFSET);
300 		reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
301 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
302 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
303 		writel(reg_val, mdata->base + SPI_CFG0_REG);
304 	}
305 
306 	reg_val = readl(mdata->base + SPI_CFG1_REG);
307 	reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
308 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
309 	writel(reg_val, mdata->base + SPI_CFG1_REG);
310 }
311 
312 static void mtk_spi_setup_packet(struct spi_master *master)
313 {
314 	u32 packet_size, packet_loop, reg_val;
315 	struct mtk_spi *mdata = spi_master_get_devdata(master);
316 
317 	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
318 	packet_loop = mdata->xfer_len / packet_size;
319 
320 	reg_val = readl(mdata->base + SPI_CFG1_REG);
321 	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
322 	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
323 	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
324 	writel(reg_val, mdata->base + SPI_CFG1_REG);
325 }
326 
327 static void mtk_spi_enable_transfer(struct spi_master *master)
328 {
329 	u32 cmd;
330 	struct mtk_spi *mdata = spi_master_get_devdata(master);
331 
332 	cmd = readl(mdata->base + SPI_CMD_REG);
333 	if (mdata->state == MTK_SPI_IDLE)
334 		cmd |= SPI_CMD_ACT;
335 	else
336 		cmd |= SPI_CMD_RESUME;
337 	writel(cmd, mdata->base + SPI_CMD_REG);
338 }
339 
340 static int mtk_spi_get_mult_delta(u32 xfer_len)
341 {
342 	u32 mult_delta;
343 
344 	if (xfer_len > MTK_SPI_PACKET_SIZE)
345 		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
346 	else
347 		mult_delta = 0;
348 
349 	return mult_delta;
350 }
351 
352 static void mtk_spi_update_mdata_len(struct spi_master *master)
353 {
354 	int mult_delta;
355 	struct mtk_spi *mdata = spi_master_get_devdata(master);
356 
357 	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
358 		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
359 			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
360 			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
361 			mdata->rx_sgl_len = mult_delta;
362 			mdata->tx_sgl_len -= mdata->xfer_len;
363 		} else {
364 			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
365 			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
366 			mdata->tx_sgl_len = mult_delta;
367 			mdata->rx_sgl_len -= mdata->xfer_len;
368 		}
369 	} else if (mdata->tx_sgl_len) {
370 		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
371 		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
372 		mdata->tx_sgl_len = mult_delta;
373 	} else if (mdata->rx_sgl_len) {
374 		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
375 		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
376 		mdata->rx_sgl_len = mult_delta;
377 	}
378 }
379 
380 static void mtk_spi_setup_dma_addr(struct spi_master *master,
381 				   struct spi_transfer *xfer)
382 {
383 	struct mtk_spi *mdata = spi_master_get_devdata(master);
384 
385 	if (mdata->tx_sgl)
386 		writel(xfer->tx_dma, mdata->base + SPI_TX_SRC_REG);
387 	if (mdata->rx_sgl)
388 		writel(xfer->rx_dma, mdata->base + SPI_RX_DST_REG);
389 }
390 
391 static int mtk_spi_fifo_transfer(struct spi_master *master,
392 				 struct spi_device *spi,
393 				 struct spi_transfer *xfer)
394 {
395 	int cnt, remainder;
396 	u32 reg_val;
397 	struct mtk_spi *mdata = spi_master_get_devdata(master);
398 
399 	mdata->cur_transfer = xfer;
400 	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
401 	mdata->num_xfered = 0;
402 	mtk_spi_prepare_transfer(master, xfer);
403 	mtk_spi_setup_packet(master);
404 
405 	cnt = xfer->len / 4;
406 	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
407 
408 	remainder = xfer->len % 4;
409 	if (remainder > 0) {
410 		reg_val = 0;
411 		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
412 		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
413 	}
414 
415 	mtk_spi_enable_transfer(master);
416 
417 	return 1;
418 }
419 
420 static int mtk_spi_dma_transfer(struct spi_master *master,
421 				struct spi_device *spi,
422 				struct spi_transfer *xfer)
423 {
424 	int cmd;
425 	struct mtk_spi *mdata = spi_master_get_devdata(master);
426 
427 	mdata->tx_sgl = NULL;
428 	mdata->rx_sgl = NULL;
429 	mdata->tx_sgl_len = 0;
430 	mdata->rx_sgl_len = 0;
431 	mdata->cur_transfer = xfer;
432 	mdata->num_xfered = 0;
433 
434 	mtk_spi_prepare_transfer(master, xfer);
435 
436 	cmd = readl(mdata->base + SPI_CMD_REG);
437 	if (xfer->tx_buf)
438 		cmd |= SPI_CMD_TX_DMA;
439 	if (xfer->rx_buf)
440 		cmd |= SPI_CMD_RX_DMA;
441 	writel(cmd, mdata->base + SPI_CMD_REG);
442 
443 	if (xfer->tx_buf)
444 		mdata->tx_sgl = xfer->tx_sg.sgl;
445 	if (xfer->rx_buf)
446 		mdata->rx_sgl = xfer->rx_sg.sgl;
447 
448 	if (mdata->tx_sgl) {
449 		xfer->tx_dma = sg_dma_address(mdata->tx_sgl);
450 		mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
451 	}
452 	if (mdata->rx_sgl) {
453 		xfer->rx_dma = sg_dma_address(mdata->rx_sgl);
454 		mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
455 	}
456 
457 	mtk_spi_update_mdata_len(master);
458 	mtk_spi_setup_packet(master);
459 	mtk_spi_setup_dma_addr(master, xfer);
460 	mtk_spi_enable_transfer(master);
461 
462 	return 1;
463 }
464 
465 static int mtk_spi_transfer_one(struct spi_master *master,
466 				struct spi_device *spi,
467 				struct spi_transfer *xfer)
468 {
469 	if (master->can_dma(master, spi, xfer))
470 		return mtk_spi_dma_transfer(master, spi, xfer);
471 	else
472 		return mtk_spi_fifo_transfer(master, spi, xfer);
473 }
474 
475 static bool mtk_spi_can_dma(struct spi_master *master,
476 			    struct spi_device *spi,
477 			    struct spi_transfer *xfer)
478 {
479 	/* Buffers for DMA transactions must be 4-byte aligned */
480 	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
481 		(unsigned long)xfer->tx_buf % 4 == 0 &&
482 		(unsigned long)xfer->rx_buf % 4 == 0);
483 }
484 
485 static int mtk_spi_setup(struct spi_device *spi)
486 {
487 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
488 
489 	if (!spi->controller_data)
490 		spi->controller_data = (void *)&mtk_default_chip_info;
491 
492 	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
493 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
494 
495 	return 0;
496 }
497 
498 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
499 {
500 	u32 cmd, reg_val, cnt, remainder, len;
501 	struct spi_master *master = dev_id;
502 	struct mtk_spi *mdata = spi_master_get_devdata(master);
503 	struct spi_transfer *trans = mdata->cur_transfer;
504 
505 	reg_val = readl(mdata->base + SPI_STATUS0_REG);
506 	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
507 		mdata->state = MTK_SPI_PAUSED;
508 	else
509 		mdata->state = MTK_SPI_IDLE;
510 
511 	if (!master->can_dma(master, master->cur_msg->spi, trans)) {
512 		if (trans->rx_buf) {
513 			cnt = mdata->xfer_len / 4;
514 			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
515 				     trans->rx_buf + mdata->num_xfered, cnt);
516 			remainder = mdata->xfer_len % 4;
517 			if (remainder > 0) {
518 				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
519 				memcpy(trans->rx_buf +
520 					mdata->num_xfered +
521 					(cnt * 4),
522 					&reg_val,
523 					remainder);
524 			}
525 		}
526 
527 		mdata->num_xfered += mdata->xfer_len;
528 		if (mdata->num_xfered == trans->len) {
529 			spi_finalize_current_transfer(master);
530 			return IRQ_HANDLED;
531 		}
532 
533 		len = trans->len - mdata->num_xfered;
534 		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, len);
535 		mtk_spi_setup_packet(master);
536 
537 		cnt = mdata->xfer_len / 4;
538 		iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
539 				trans->tx_buf + mdata->num_xfered, cnt);
540 
541 		remainder = mdata->xfer_len % 4;
542 		if (remainder > 0) {
543 			reg_val = 0;
544 			memcpy(&reg_val,
545 				trans->tx_buf + (cnt * 4) + mdata->num_xfered,
546 				remainder);
547 			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
548 		}
549 
550 		mtk_spi_enable_transfer(master);
551 
552 		return IRQ_HANDLED;
553 	}
554 
555 	if (mdata->tx_sgl)
556 		trans->tx_dma += mdata->xfer_len;
557 	if (mdata->rx_sgl)
558 		trans->rx_dma += mdata->xfer_len;
559 
560 	if (mdata->tx_sgl && (mdata->tx_sgl_len == 0)) {
561 		mdata->tx_sgl = sg_next(mdata->tx_sgl);
562 		if (mdata->tx_sgl) {
563 			trans->tx_dma = sg_dma_address(mdata->tx_sgl);
564 			mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
565 		}
566 	}
567 	if (mdata->rx_sgl && (mdata->rx_sgl_len == 0)) {
568 		mdata->rx_sgl = sg_next(mdata->rx_sgl);
569 		if (mdata->rx_sgl) {
570 			trans->rx_dma = sg_dma_address(mdata->rx_sgl);
571 			mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
572 		}
573 	}
574 
575 	if (!mdata->tx_sgl && !mdata->rx_sgl) {
576 		/* spi disable dma */
577 		cmd = readl(mdata->base + SPI_CMD_REG);
578 		cmd &= ~SPI_CMD_TX_DMA;
579 		cmd &= ~SPI_CMD_RX_DMA;
580 		writel(cmd, mdata->base + SPI_CMD_REG);
581 
582 		spi_finalize_current_transfer(master);
583 		return IRQ_HANDLED;
584 	}
585 
586 	mtk_spi_update_mdata_len(master);
587 	mtk_spi_setup_packet(master);
588 	mtk_spi_setup_dma_addr(master, trans);
589 	mtk_spi_enable_transfer(master);
590 
591 	return IRQ_HANDLED;
592 }
593 
594 static int mtk_spi_probe(struct platform_device *pdev)
595 {
596 	struct spi_master *master;
597 	struct mtk_spi *mdata;
598 	const struct of_device_id *of_id;
599 	struct resource *res;
600 	int i, irq, ret;
601 
602 	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
603 	if (!master) {
604 		dev_err(&pdev->dev, "failed to alloc spi master\n");
605 		return -ENOMEM;
606 	}
607 
608 	master->auto_runtime_pm = true;
609 	master->dev.of_node = pdev->dev.of_node;
610 	master->mode_bits = SPI_CPOL | SPI_CPHA;
611 
612 	master->set_cs = mtk_spi_set_cs;
613 	master->prepare_message = mtk_spi_prepare_message;
614 	master->transfer_one = mtk_spi_transfer_one;
615 	master->can_dma = mtk_spi_can_dma;
616 	master->setup = mtk_spi_setup;
617 
618 	of_id = of_match_node(mtk_spi_of_match, pdev->dev.of_node);
619 	if (!of_id) {
620 		dev_err(&pdev->dev, "failed to probe of_node\n");
621 		ret = -EINVAL;
622 		goto err_put_master;
623 	}
624 
625 	mdata = spi_master_get_devdata(master);
626 	mdata->dev_comp = of_id->data;
627 	if (mdata->dev_comp->must_tx)
628 		master->flags = SPI_MASTER_MUST_TX;
629 
630 	if (mdata->dev_comp->need_pad_sel) {
631 		mdata->pad_num = of_property_count_u32_elems(
632 			pdev->dev.of_node,
633 			"mediatek,pad-select");
634 		if (mdata->pad_num < 0) {
635 			dev_err(&pdev->dev,
636 				"No 'mediatek,pad-select' property\n");
637 			ret = -EINVAL;
638 			goto err_put_master;
639 		}
640 
641 		mdata->pad_sel = devm_kmalloc_array(&pdev->dev, mdata->pad_num,
642 						    sizeof(u32), GFP_KERNEL);
643 		if (!mdata->pad_sel) {
644 			ret = -ENOMEM;
645 			goto err_put_master;
646 		}
647 
648 		for (i = 0; i < mdata->pad_num; i++) {
649 			of_property_read_u32_index(pdev->dev.of_node,
650 						   "mediatek,pad-select",
651 						   i, &mdata->pad_sel[i]);
652 			if (mdata->pad_sel[i] > MT8173_SPI_MAX_PAD_SEL) {
653 				dev_err(&pdev->dev, "wrong pad-sel[%d]: %u\n",
654 					i, mdata->pad_sel[i]);
655 				ret = -EINVAL;
656 				goto err_put_master;
657 			}
658 		}
659 	}
660 
661 	platform_set_drvdata(pdev, master);
662 
663 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
664 	if (!res) {
665 		ret = -ENODEV;
666 		dev_err(&pdev->dev, "failed to determine base address\n");
667 		goto err_put_master;
668 	}
669 
670 	mdata->base = devm_ioremap_resource(&pdev->dev, res);
671 	if (IS_ERR(mdata->base)) {
672 		ret = PTR_ERR(mdata->base);
673 		goto err_put_master;
674 	}
675 
676 	irq = platform_get_irq(pdev, 0);
677 	if (irq < 0) {
678 		dev_err(&pdev->dev, "failed to get irq (%d)\n", irq);
679 		ret = irq;
680 		goto err_put_master;
681 	}
682 
683 	if (!pdev->dev.dma_mask)
684 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
685 
686 	ret = devm_request_irq(&pdev->dev, irq, mtk_spi_interrupt,
687 			       IRQF_TRIGGER_NONE, dev_name(&pdev->dev), master);
688 	if (ret) {
689 		dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
690 		goto err_put_master;
691 	}
692 
693 	mdata->parent_clk = devm_clk_get(&pdev->dev, "parent-clk");
694 	if (IS_ERR(mdata->parent_clk)) {
695 		ret = PTR_ERR(mdata->parent_clk);
696 		dev_err(&pdev->dev, "failed to get parent-clk: %d\n", ret);
697 		goto err_put_master;
698 	}
699 
700 	mdata->sel_clk = devm_clk_get(&pdev->dev, "sel-clk");
701 	if (IS_ERR(mdata->sel_clk)) {
702 		ret = PTR_ERR(mdata->sel_clk);
703 		dev_err(&pdev->dev, "failed to get sel-clk: %d\n", ret);
704 		goto err_put_master;
705 	}
706 
707 	mdata->spi_clk = devm_clk_get(&pdev->dev, "spi-clk");
708 	if (IS_ERR(mdata->spi_clk)) {
709 		ret = PTR_ERR(mdata->spi_clk);
710 		dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
711 		goto err_put_master;
712 	}
713 
714 	ret = clk_prepare_enable(mdata->spi_clk);
715 	if (ret < 0) {
716 		dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
717 		goto err_put_master;
718 	}
719 
720 	ret = clk_set_parent(mdata->sel_clk, mdata->parent_clk);
721 	if (ret < 0) {
722 		dev_err(&pdev->dev, "failed to clk_set_parent (%d)\n", ret);
723 		clk_disable_unprepare(mdata->spi_clk);
724 		goto err_put_master;
725 	}
726 
727 	clk_disable_unprepare(mdata->spi_clk);
728 
729 	pm_runtime_enable(&pdev->dev);
730 
731 	ret = devm_spi_register_master(&pdev->dev, master);
732 	if (ret) {
733 		dev_err(&pdev->dev, "failed to register master (%d)\n", ret);
734 		goto err_disable_runtime_pm;
735 	}
736 
737 	if (mdata->dev_comp->need_pad_sel) {
738 		if (mdata->pad_num != master->num_chipselect) {
739 			dev_err(&pdev->dev,
740 				"pad_num does not match num_chipselect(%d != %d)\n",
741 				mdata->pad_num, master->num_chipselect);
742 			ret = -EINVAL;
743 			goto err_disable_runtime_pm;
744 		}
745 
746 		if (!master->cs_gpios && master->num_chipselect > 1) {
747 			dev_err(&pdev->dev,
748 				"cs_gpios not specified and num_chipselect > 1\n");
749 			ret = -EINVAL;
750 			goto err_disable_runtime_pm;
751 		}
752 
753 		if (master->cs_gpios) {
754 			for (i = 0; i < master->num_chipselect; i++) {
755 				ret = devm_gpio_request(&pdev->dev,
756 							master->cs_gpios[i],
757 							dev_name(&pdev->dev));
758 				if (ret) {
759 					dev_err(&pdev->dev,
760 						"can't get CS GPIO %i\n", i);
761 					goto err_disable_runtime_pm;
762 				}
763 			}
764 		}
765 	}
766 
767 	return 0;
768 
769 err_disable_runtime_pm:
770 	pm_runtime_disable(&pdev->dev);
771 err_put_master:
772 	spi_master_put(master);
773 
774 	return ret;
775 }
776 
777 static int mtk_spi_remove(struct platform_device *pdev)
778 {
779 	struct spi_master *master = platform_get_drvdata(pdev);
780 	struct mtk_spi *mdata = spi_master_get_devdata(master);
781 
782 	pm_runtime_disable(&pdev->dev);
783 
784 	mtk_spi_reset(mdata);
785 
786 	return 0;
787 }
788 
789 #ifdef CONFIG_PM_SLEEP
790 static int mtk_spi_suspend(struct device *dev)
791 {
792 	int ret;
793 	struct spi_master *master = dev_get_drvdata(dev);
794 	struct mtk_spi *mdata = spi_master_get_devdata(master);
795 
796 	ret = spi_master_suspend(master);
797 	if (ret)
798 		return ret;
799 
800 	if (!pm_runtime_suspended(dev))
801 		clk_disable_unprepare(mdata->spi_clk);
802 
803 	return ret;
804 }
805 
806 static int mtk_spi_resume(struct device *dev)
807 {
808 	int ret;
809 	struct spi_master *master = dev_get_drvdata(dev);
810 	struct mtk_spi *mdata = spi_master_get_devdata(master);
811 
812 	if (!pm_runtime_suspended(dev)) {
813 		ret = clk_prepare_enable(mdata->spi_clk);
814 		if (ret < 0) {
815 			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
816 			return ret;
817 		}
818 	}
819 
820 	ret = spi_master_resume(master);
821 	if (ret < 0)
822 		clk_disable_unprepare(mdata->spi_clk);
823 
824 	return ret;
825 }
826 #endif /* CONFIG_PM_SLEEP */
827 
828 #ifdef CONFIG_PM
829 static int mtk_spi_runtime_suspend(struct device *dev)
830 {
831 	struct spi_master *master = dev_get_drvdata(dev);
832 	struct mtk_spi *mdata = spi_master_get_devdata(master);
833 
834 	clk_disable_unprepare(mdata->spi_clk);
835 
836 	return 0;
837 }
838 
839 static int mtk_spi_runtime_resume(struct device *dev)
840 {
841 	struct spi_master *master = dev_get_drvdata(dev);
842 	struct mtk_spi *mdata = spi_master_get_devdata(master);
843 	int ret;
844 
845 	ret = clk_prepare_enable(mdata->spi_clk);
846 	if (ret < 0) {
847 		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
848 		return ret;
849 	}
850 
851 	return 0;
852 }
853 #endif /* CONFIG_PM */
854 
855 static const struct dev_pm_ops mtk_spi_pm = {
856 	SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_suspend, mtk_spi_resume)
857 	SET_RUNTIME_PM_OPS(mtk_spi_runtime_suspend,
858 			   mtk_spi_runtime_resume, NULL)
859 };
860 
861 static struct platform_driver mtk_spi_driver = {
862 	.driver = {
863 		.name = "mtk-spi",
864 		.pm	= &mtk_spi_pm,
865 		.of_match_table = mtk_spi_of_match,
866 	},
867 	.probe = mtk_spi_probe,
868 	.remove = mtk_spi_remove,
869 };
870 
871 module_platform_driver(mtk_spi_driver);
872 
873 MODULE_DESCRIPTION("MTK SPI Controller driver");
874 MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
875 MODULE_LICENSE("GPL v2");
876 MODULE_ALIAS("platform:mtk-spi");
877