xref: /openbmc/linux/drivers/spi/spi-mt65xx.c (revision fcc8487d)
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 
39 #define SPI_CFG0_SCK_HIGH_OFFSET          0
40 #define SPI_CFG0_SCK_LOW_OFFSET           8
41 #define SPI_CFG0_CS_HOLD_OFFSET           16
42 #define SPI_CFG0_CS_SETUP_OFFSET          24
43 
44 #define SPI_CFG1_CS_IDLE_OFFSET           0
45 #define SPI_CFG1_PACKET_LOOP_OFFSET       8
46 #define SPI_CFG1_PACKET_LENGTH_OFFSET     16
47 #define SPI_CFG1_GET_TICK_DLY_OFFSET      30
48 
49 #define SPI_CFG1_CS_IDLE_MASK             0xff
50 #define SPI_CFG1_PACKET_LOOP_MASK         0xff00
51 #define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
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_CPHA                 BIT(8)
59 #define SPI_CMD_CPOL                 BIT(9)
60 #define SPI_CMD_RX_DMA               BIT(10)
61 #define SPI_CMD_TX_DMA               BIT(11)
62 #define SPI_CMD_TXMSBF               BIT(12)
63 #define SPI_CMD_RXMSBF               BIT(13)
64 #define SPI_CMD_RX_ENDIAN            BIT(14)
65 #define SPI_CMD_TX_ENDIAN            BIT(15)
66 #define SPI_CMD_FINISH_IE            BIT(16)
67 #define SPI_CMD_PAUSE_IE             BIT(17)
68 
69 #define MT8173_SPI_MAX_PAD_SEL 3
70 
71 #define MTK_SPI_PAUSE_INT_STATUS 0x2
72 
73 #define MTK_SPI_IDLE 0
74 #define MTK_SPI_PAUSED 1
75 
76 #define MTK_SPI_MAX_FIFO_SIZE 32U
77 #define MTK_SPI_PACKET_SIZE 1024
78 
79 struct mtk_spi_compatible {
80 	bool need_pad_sel;
81 	/* Must explicitly send dummy Tx bytes to do Rx only transfer */
82 	bool must_tx;
83 };
84 
85 struct mtk_spi {
86 	void __iomem *base;
87 	u32 state;
88 	int pad_num;
89 	u32 *pad_sel;
90 	struct clk *parent_clk, *sel_clk, *spi_clk;
91 	struct spi_transfer *cur_transfer;
92 	u32 xfer_len;
93 	struct scatterlist *tx_sgl, *rx_sgl;
94 	u32 tx_sgl_len, rx_sgl_len;
95 	const struct mtk_spi_compatible *dev_comp;
96 };
97 
98 static const struct mtk_spi_compatible mtk_common_compat;
99 static const struct mtk_spi_compatible mt8173_compat = {
100 	.need_pad_sel = true,
101 	.must_tx = true,
102 };
103 
104 /*
105  * A piece of default chip info unless the platform
106  * supplies it.
107  */
108 static const struct mtk_chip_config mtk_default_chip_info = {
109 	.rx_mlsb = 1,
110 	.tx_mlsb = 1,
111 };
112 
113 static const struct of_device_id mtk_spi_of_match[] = {
114 	{ .compatible = "mediatek,mt2701-spi",
115 		.data = (void *)&mtk_common_compat,
116 	},
117 	{ .compatible = "mediatek,mt6589-spi",
118 		.data = (void *)&mtk_common_compat,
119 	},
120 	{ .compatible = "mediatek,mt8135-spi",
121 		.data = (void *)&mtk_common_compat,
122 	},
123 	{ .compatible = "mediatek,mt8173-spi",
124 		.data = (void *)&mt8173_compat,
125 	},
126 	{}
127 };
128 MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
129 
130 static void mtk_spi_reset(struct mtk_spi *mdata)
131 {
132 	u32 reg_val;
133 
134 	/* set the software reset bit in SPI_CMD_REG. */
135 	reg_val = readl(mdata->base + SPI_CMD_REG);
136 	reg_val |= SPI_CMD_RST;
137 	writel(reg_val, mdata->base + SPI_CMD_REG);
138 
139 	reg_val = readl(mdata->base + SPI_CMD_REG);
140 	reg_val &= ~SPI_CMD_RST;
141 	writel(reg_val, mdata->base + SPI_CMD_REG);
142 }
143 
144 static int mtk_spi_prepare_message(struct spi_master *master,
145 				   struct spi_message *msg)
146 {
147 	u16 cpha, cpol;
148 	u32 reg_val;
149 	struct spi_device *spi = msg->spi;
150 	struct mtk_chip_config *chip_config = spi->controller_data;
151 	struct mtk_spi *mdata = spi_master_get_devdata(master);
152 
153 	cpha = spi->mode & SPI_CPHA ? 1 : 0;
154 	cpol = spi->mode & SPI_CPOL ? 1 : 0;
155 
156 	reg_val = readl(mdata->base + SPI_CMD_REG);
157 	if (cpha)
158 		reg_val |= SPI_CMD_CPHA;
159 	else
160 		reg_val &= ~SPI_CMD_CPHA;
161 	if (cpol)
162 		reg_val |= SPI_CMD_CPOL;
163 	else
164 		reg_val &= ~SPI_CMD_CPOL;
165 
166 	/* set the mlsbx and mlsbtx */
167 	if (chip_config->tx_mlsb)
168 		reg_val |= SPI_CMD_TXMSBF;
169 	else
170 		reg_val &= ~SPI_CMD_TXMSBF;
171 	if (chip_config->rx_mlsb)
172 		reg_val |= SPI_CMD_RXMSBF;
173 	else
174 		reg_val &= ~SPI_CMD_RXMSBF;
175 
176 	/* set the tx/rx endian */
177 #ifdef __LITTLE_ENDIAN
178 	reg_val &= ~SPI_CMD_TX_ENDIAN;
179 	reg_val &= ~SPI_CMD_RX_ENDIAN;
180 #else
181 	reg_val |= SPI_CMD_TX_ENDIAN;
182 	reg_val |= SPI_CMD_RX_ENDIAN;
183 #endif
184 
185 	/* set finish and pause interrupt always enable */
186 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;
187 
188 	/* disable dma mode */
189 	reg_val &= ~(SPI_CMD_TX_DMA | SPI_CMD_RX_DMA);
190 
191 	/* disable deassert mode */
192 	reg_val &= ~SPI_CMD_DEASSERT;
193 
194 	writel(reg_val, mdata->base + SPI_CMD_REG);
195 
196 	/* pad select */
197 	if (mdata->dev_comp->need_pad_sel)
198 		writel(mdata->pad_sel[spi->chip_select],
199 		       mdata->base + SPI_PAD_SEL_REG);
200 
201 	return 0;
202 }
203 
204 static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
205 {
206 	u32 reg_val;
207 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
208 
209 	reg_val = readl(mdata->base + SPI_CMD_REG);
210 	if (!enable) {
211 		reg_val |= SPI_CMD_PAUSE_EN;
212 		writel(reg_val, mdata->base + SPI_CMD_REG);
213 	} else {
214 		reg_val &= ~SPI_CMD_PAUSE_EN;
215 		writel(reg_val, mdata->base + SPI_CMD_REG);
216 		mdata->state = MTK_SPI_IDLE;
217 		mtk_spi_reset(mdata);
218 	}
219 }
220 
221 static void mtk_spi_prepare_transfer(struct spi_master *master,
222 				     struct spi_transfer *xfer)
223 {
224 	u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0;
225 	struct mtk_spi *mdata = spi_master_get_devdata(master);
226 
227 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
228 	if (xfer->speed_hz < spi_clk_hz / 2)
229 		div = DIV_ROUND_UP(spi_clk_hz, xfer->speed_hz);
230 	else
231 		div = 1;
232 
233 	sck_time = (div + 1) / 2;
234 	cs_time = sck_time * 2;
235 
236 	reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_HIGH_OFFSET);
237 	reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
238 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
239 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
240 	writel(reg_val, mdata->base + SPI_CFG0_REG);
241 
242 	reg_val = readl(mdata->base + SPI_CFG1_REG);
243 	reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
244 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
245 	writel(reg_val, mdata->base + SPI_CFG1_REG);
246 }
247 
248 static void mtk_spi_setup_packet(struct spi_master *master)
249 {
250 	u32 packet_size, packet_loop, reg_val;
251 	struct mtk_spi *mdata = spi_master_get_devdata(master);
252 
253 	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
254 	packet_loop = mdata->xfer_len / packet_size;
255 
256 	reg_val = readl(mdata->base + SPI_CFG1_REG);
257 	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
258 	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
259 	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
260 	writel(reg_val, mdata->base + SPI_CFG1_REG);
261 }
262 
263 static void mtk_spi_enable_transfer(struct spi_master *master)
264 {
265 	u32 cmd;
266 	struct mtk_spi *mdata = spi_master_get_devdata(master);
267 
268 	cmd = readl(mdata->base + SPI_CMD_REG);
269 	if (mdata->state == MTK_SPI_IDLE)
270 		cmd |= SPI_CMD_ACT;
271 	else
272 		cmd |= SPI_CMD_RESUME;
273 	writel(cmd, mdata->base + SPI_CMD_REG);
274 }
275 
276 static int mtk_spi_get_mult_delta(u32 xfer_len)
277 {
278 	u32 mult_delta;
279 
280 	if (xfer_len > MTK_SPI_PACKET_SIZE)
281 		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
282 	else
283 		mult_delta = 0;
284 
285 	return mult_delta;
286 }
287 
288 static void mtk_spi_update_mdata_len(struct spi_master *master)
289 {
290 	int mult_delta;
291 	struct mtk_spi *mdata = spi_master_get_devdata(master);
292 
293 	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
294 		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
295 			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
296 			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
297 			mdata->rx_sgl_len = mult_delta;
298 			mdata->tx_sgl_len -= mdata->xfer_len;
299 		} else {
300 			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
301 			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
302 			mdata->tx_sgl_len = mult_delta;
303 			mdata->rx_sgl_len -= mdata->xfer_len;
304 		}
305 	} else if (mdata->tx_sgl_len) {
306 		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
307 		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
308 		mdata->tx_sgl_len = mult_delta;
309 	} else if (mdata->rx_sgl_len) {
310 		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
311 		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
312 		mdata->rx_sgl_len = mult_delta;
313 	}
314 }
315 
316 static void mtk_spi_setup_dma_addr(struct spi_master *master,
317 				   struct spi_transfer *xfer)
318 {
319 	struct mtk_spi *mdata = spi_master_get_devdata(master);
320 
321 	if (mdata->tx_sgl)
322 		writel(xfer->tx_dma, mdata->base + SPI_TX_SRC_REG);
323 	if (mdata->rx_sgl)
324 		writel(xfer->rx_dma, mdata->base + SPI_RX_DST_REG);
325 }
326 
327 static int mtk_spi_fifo_transfer(struct spi_master *master,
328 				 struct spi_device *spi,
329 				 struct spi_transfer *xfer)
330 {
331 	int cnt, remainder;
332 	u32 reg_val;
333 	struct mtk_spi *mdata = spi_master_get_devdata(master);
334 
335 	mdata->cur_transfer = xfer;
336 	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
337 	mtk_spi_prepare_transfer(master, xfer);
338 	mtk_spi_setup_packet(master);
339 
340 	cnt = xfer->len / 4;
341 	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
342 
343 	remainder = xfer->len % 4;
344 	if (remainder > 0) {
345 		reg_val = 0;
346 		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
347 		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
348 	}
349 
350 	mtk_spi_enable_transfer(master);
351 
352 	return 1;
353 }
354 
355 static int mtk_spi_dma_transfer(struct spi_master *master,
356 				struct spi_device *spi,
357 				struct spi_transfer *xfer)
358 {
359 	int cmd;
360 	struct mtk_spi *mdata = spi_master_get_devdata(master);
361 
362 	mdata->tx_sgl = NULL;
363 	mdata->rx_sgl = NULL;
364 	mdata->tx_sgl_len = 0;
365 	mdata->rx_sgl_len = 0;
366 	mdata->cur_transfer = xfer;
367 
368 	mtk_spi_prepare_transfer(master, xfer);
369 
370 	cmd = readl(mdata->base + SPI_CMD_REG);
371 	if (xfer->tx_buf)
372 		cmd |= SPI_CMD_TX_DMA;
373 	if (xfer->rx_buf)
374 		cmd |= SPI_CMD_RX_DMA;
375 	writel(cmd, mdata->base + SPI_CMD_REG);
376 
377 	if (xfer->tx_buf)
378 		mdata->tx_sgl = xfer->tx_sg.sgl;
379 	if (xfer->rx_buf)
380 		mdata->rx_sgl = xfer->rx_sg.sgl;
381 
382 	if (mdata->tx_sgl) {
383 		xfer->tx_dma = sg_dma_address(mdata->tx_sgl);
384 		mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
385 	}
386 	if (mdata->rx_sgl) {
387 		xfer->rx_dma = sg_dma_address(mdata->rx_sgl);
388 		mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
389 	}
390 
391 	mtk_spi_update_mdata_len(master);
392 	mtk_spi_setup_packet(master);
393 	mtk_spi_setup_dma_addr(master, xfer);
394 	mtk_spi_enable_transfer(master);
395 
396 	return 1;
397 }
398 
399 static int mtk_spi_transfer_one(struct spi_master *master,
400 				struct spi_device *spi,
401 				struct spi_transfer *xfer)
402 {
403 	if (master->can_dma(master, spi, xfer))
404 		return mtk_spi_dma_transfer(master, spi, xfer);
405 	else
406 		return mtk_spi_fifo_transfer(master, spi, xfer);
407 }
408 
409 static bool mtk_spi_can_dma(struct spi_master *master,
410 			    struct spi_device *spi,
411 			    struct spi_transfer *xfer)
412 {
413 	/* Buffers for DMA transactions must be 4-byte aligned */
414 	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
415 		(unsigned long)xfer->tx_buf % 4 == 0 &&
416 		(unsigned long)xfer->rx_buf % 4 == 0);
417 }
418 
419 static int mtk_spi_setup(struct spi_device *spi)
420 {
421 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
422 
423 	if (!spi->controller_data)
424 		spi->controller_data = (void *)&mtk_default_chip_info;
425 
426 	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
427 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
428 
429 	return 0;
430 }
431 
432 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
433 {
434 	u32 cmd, reg_val, cnt, remainder;
435 	struct spi_master *master = dev_id;
436 	struct mtk_spi *mdata = spi_master_get_devdata(master);
437 	struct spi_transfer *trans = mdata->cur_transfer;
438 
439 	reg_val = readl(mdata->base + SPI_STATUS0_REG);
440 	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
441 		mdata->state = MTK_SPI_PAUSED;
442 	else
443 		mdata->state = MTK_SPI_IDLE;
444 
445 	if (!master->can_dma(master, master->cur_msg->spi, trans)) {
446 		if (trans->rx_buf) {
447 			cnt = mdata->xfer_len / 4;
448 			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
449 				     trans->rx_buf, cnt);
450 			remainder = mdata->xfer_len % 4;
451 			if (remainder > 0) {
452 				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
453 				memcpy(trans->rx_buf + (cnt * 4),
454 					&reg_val, remainder);
455 			}
456 		}
457 
458 		trans->len -= mdata->xfer_len;
459 		if (!trans->len) {
460 			spi_finalize_current_transfer(master);
461 			return IRQ_HANDLED;
462 		}
463 
464 		if (trans->tx_buf)
465 			trans->tx_buf += mdata->xfer_len;
466 		if (trans->rx_buf)
467 			trans->rx_buf += mdata->xfer_len;
468 
469 		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, trans->len);
470 		mtk_spi_setup_packet(master);
471 
472 		cnt = trans->len / 4;
473 		iowrite32_rep(mdata->base + SPI_TX_DATA_REG, trans->tx_buf, cnt);
474 
475 		remainder = trans->len % 4;
476 		if (remainder > 0) {
477 			reg_val = 0;
478 			memcpy(&reg_val, trans->tx_buf + (cnt * 4), remainder);
479 			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
480 		}
481 
482 		mtk_spi_enable_transfer(master);
483 
484 		return IRQ_HANDLED;
485 	}
486 
487 	if (mdata->tx_sgl)
488 		trans->tx_dma += mdata->xfer_len;
489 	if (mdata->rx_sgl)
490 		trans->rx_dma += mdata->xfer_len;
491 
492 	if (mdata->tx_sgl && (mdata->tx_sgl_len == 0)) {
493 		mdata->tx_sgl = sg_next(mdata->tx_sgl);
494 		if (mdata->tx_sgl) {
495 			trans->tx_dma = sg_dma_address(mdata->tx_sgl);
496 			mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
497 		}
498 	}
499 	if (mdata->rx_sgl && (mdata->rx_sgl_len == 0)) {
500 		mdata->rx_sgl = sg_next(mdata->rx_sgl);
501 		if (mdata->rx_sgl) {
502 			trans->rx_dma = sg_dma_address(mdata->rx_sgl);
503 			mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
504 		}
505 	}
506 
507 	if (!mdata->tx_sgl && !mdata->rx_sgl) {
508 		/* spi disable dma */
509 		cmd = readl(mdata->base + SPI_CMD_REG);
510 		cmd &= ~SPI_CMD_TX_DMA;
511 		cmd &= ~SPI_CMD_RX_DMA;
512 		writel(cmd, mdata->base + SPI_CMD_REG);
513 
514 		spi_finalize_current_transfer(master);
515 		return IRQ_HANDLED;
516 	}
517 
518 	mtk_spi_update_mdata_len(master);
519 	mtk_spi_setup_packet(master);
520 	mtk_spi_setup_dma_addr(master, trans);
521 	mtk_spi_enable_transfer(master);
522 
523 	return IRQ_HANDLED;
524 }
525 
526 static int mtk_spi_probe(struct platform_device *pdev)
527 {
528 	struct spi_master *master;
529 	struct mtk_spi *mdata;
530 	const struct of_device_id *of_id;
531 	struct resource *res;
532 	int i, irq, ret;
533 
534 	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
535 	if (!master) {
536 		dev_err(&pdev->dev, "failed to alloc spi master\n");
537 		return -ENOMEM;
538 	}
539 
540 	master->auto_runtime_pm = true;
541 	master->dev.of_node = pdev->dev.of_node;
542 	master->mode_bits = SPI_CPOL | SPI_CPHA;
543 
544 	master->set_cs = mtk_spi_set_cs;
545 	master->prepare_message = mtk_spi_prepare_message;
546 	master->transfer_one = mtk_spi_transfer_one;
547 	master->can_dma = mtk_spi_can_dma;
548 	master->setup = mtk_spi_setup;
549 
550 	of_id = of_match_node(mtk_spi_of_match, pdev->dev.of_node);
551 	if (!of_id) {
552 		dev_err(&pdev->dev, "failed to probe of_node\n");
553 		ret = -EINVAL;
554 		goto err_put_master;
555 	}
556 
557 	mdata = spi_master_get_devdata(master);
558 	mdata->dev_comp = of_id->data;
559 	if (mdata->dev_comp->must_tx)
560 		master->flags = SPI_MASTER_MUST_TX;
561 
562 	if (mdata->dev_comp->need_pad_sel) {
563 		mdata->pad_num = of_property_count_u32_elems(
564 			pdev->dev.of_node,
565 			"mediatek,pad-select");
566 		if (mdata->pad_num < 0) {
567 			dev_err(&pdev->dev,
568 				"No 'mediatek,pad-select' property\n");
569 			ret = -EINVAL;
570 			goto err_put_master;
571 		}
572 
573 		mdata->pad_sel = devm_kmalloc_array(&pdev->dev, mdata->pad_num,
574 						    sizeof(u32), GFP_KERNEL);
575 		if (!mdata->pad_sel) {
576 			ret = -ENOMEM;
577 			goto err_put_master;
578 		}
579 
580 		for (i = 0; i < mdata->pad_num; i++) {
581 			of_property_read_u32_index(pdev->dev.of_node,
582 						   "mediatek,pad-select",
583 						   i, &mdata->pad_sel[i]);
584 			if (mdata->pad_sel[i] > MT8173_SPI_MAX_PAD_SEL) {
585 				dev_err(&pdev->dev, "wrong pad-sel[%d]: %u\n",
586 					i, mdata->pad_sel[i]);
587 				ret = -EINVAL;
588 				goto err_put_master;
589 			}
590 		}
591 	}
592 
593 	platform_set_drvdata(pdev, master);
594 
595 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
596 	if (!res) {
597 		ret = -ENODEV;
598 		dev_err(&pdev->dev, "failed to determine base address\n");
599 		goto err_put_master;
600 	}
601 
602 	mdata->base = devm_ioremap_resource(&pdev->dev, res);
603 	if (IS_ERR(mdata->base)) {
604 		ret = PTR_ERR(mdata->base);
605 		goto err_put_master;
606 	}
607 
608 	irq = platform_get_irq(pdev, 0);
609 	if (irq < 0) {
610 		dev_err(&pdev->dev, "failed to get irq (%d)\n", irq);
611 		ret = irq;
612 		goto err_put_master;
613 	}
614 
615 	if (!pdev->dev.dma_mask)
616 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
617 
618 	ret = devm_request_irq(&pdev->dev, irq, mtk_spi_interrupt,
619 			       IRQF_TRIGGER_NONE, dev_name(&pdev->dev), master);
620 	if (ret) {
621 		dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
622 		goto err_put_master;
623 	}
624 
625 	mdata->parent_clk = devm_clk_get(&pdev->dev, "parent-clk");
626 	if (IS_ERR(mdata->parent_clk)) {
627 		ret = PTR_ERR(mdata->parent_clk);
628 		dev_err(&pdev->dev, "failed to get parent-clk: %d\n", ret);
629 		goto err_put_master;
630 	}
631 
632 	mdata->sel_clk = devm_clk_get(&pdev->dev, "sel-clk");
633 	if (IS_ERR(mdata->sel_clk)) {
634 		ret = PTR_ERR(mdata->sel_clk);
635 		dev_err(&pdev->dev, "failed to get sel-clk: %d\n", ret);
636 		goto err_put_master;
637 	}
638 
639 	mdata->spi_clk = devm_clk_get(&pdev->dev, "spi-clk");
640 	if (IS_ERR(mdata->spi_clk)) {
641 		ret = PTR_ERR(mdata->spi_clk);
642 		dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
643 		goto err_put_master;
644 	}
645 
646 	ret = clk_prepare_enable(mdata->spi_clk);
647 	if (ret < 0) {
648 		dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
649 		goto err_put_master;
650 	}
651 
652 	ret = clk_set_parent(mdata->sel_clk, mdata->parent_clk);
653 	if (ret < 0) {
654 		dev_err(&pdev->dev, "failed to clk_set_parent (%d)\n", ret);
655 		clk_disable_unprepare(mdata->spi_clk);
656 		goto err_put_master;
657 	}
658 
659 	clk_disable_unprepare(mdata->spi_clk);
660 
661 	pm_runtime_enable(&pdev->dev);
662 
663 	ret = devm_spi_register_master(&pdev->dev, master);
664 	if (ret) {
665 		dev_err(&pdev->dev, "failed to register master (%d)\n", ret);
666 		goto err_disable_runtime_pm;
667 	}
668 
669 	if (mdata->dev_comp->need_pad_sel) {
670 		if (mdata->pad_num != master->num_chipselect) {
671 			dev_err(&pdev->dev,
672 				"pad_num does not match num_chipselect(%d != %d)\n",
673 				mdata->pad_num, master->num_chipselect);
674 			ret = -EINVAL;
675 			goto err_disable_runtime_pm;
676 		}
677 
678 		if (!master->cs_gpios && master->num_chipselect > 1) {
679 			dev_err(&pdev->dev,
680 				"cs_gpios not specified and num_chipselect > 1\n");
681 			ret = -EINVAL;
682 			goto err_disable_runtime_pm;
683 		}
684 
685 		if (master->cs_gpios) {
686 			for (i = 0; i < master->num_chipselect; i++) {
687 				ret = devm_gpio_request(&pdev->dev,
688 							master->cs_gpios[i],
689 							dev_name(&pdev->dev));
690 				if (ret) {
691 					dev_err(&pdev->dev,
692 						"can't get CS GPIO %i\n", i);
693 					goto err_disable_runtime_pm;
694 				}
695 			}
696 		}
697 	}
698 
699 	return 0;
700 
701 err_disable_runtime_pm:
702 	pm_runtime_disable(&pdev->dev);
703 err_put_master:
704 	spi_master_put(master);
705 
706 	return ret;
707 }
708 
709 static int mtk_spi_remove(struct platform_device *pdev)
710 {
711 	struct spi_master *master = platform_get_drvdata(pdev);
712 	struct mtk_spi *mdata = spi_master_get_devdata(master);
713 
714 	pm_runtime_disable(&pdev->dev);
715 
716 	mtk_spi_reset(mdata);
717 
718 	return 0;
719 }
720 
721 #ifdef CONFIG_PM_SLEEP
722 static int mtk_spi_suspend(struct device *dev)
723 {
724 	int ret;
725 	struct spi_master *master = dev_get_drvdata(dev);
726 	struct mtk_spi *mdata = spi_master_get_devdata(master);
727 
728 	ret = spi_master_suspend(master);
729 	if (ret)
730 		return ret;
731 
732 	if (!pm_runtime_suspended(dev))
733 		clk_disable_unprepare(mdata->spi_clk);
734 
735 	return ret;
736 }
737 
738 static int mtk_spi_resume(struct device *dev)
739 {
740 	int ret;
741 	struct spi_master *master = dev_get_drvdata(dev);
742 	struct mtk_spi *mdata = spi_master_get_devdata(master);
743 
744 	if (!pm_runtime_suspended(dev)) {
745 		ret = clk_prepare_enable(mdata->spi_clk);
746 		if (ret < 0) {
747 			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
748 			return ret;
749 		}
750 	}
751 
752 	ret = spi_master_resume(master);
753 	if (ret < 0)
754 		clk_disable_unprepare(mdata->spi_clk);
755 
756 	return ret;
757 }
758 #endif /* CONFIG_PM_SLEEP */
759 
760 #ifdef CONFIG_PM
761 static int mtk_spi_runtime_suspend(struct device *dev)
762 {
763 	struct spi_master *master = dev_get_drvdata(dev);
764 	struct mtk_spi *mdata = spi_master_get_devdata(master);
765 
766 	clk_disable_unprepare(mdata->spi_clk);
767 
768 	return 0;
769 }
770 
771 static int mtk_spi_runtime_resume(struct device *dev)
772 {
773 	struct spi_master *master = dev_get_drvdata(dev);
774 	struct mtk_spi *mdata = spi_master_get_devdata(master);
775 	int ret;
776 
777 	ret = clk_prepare_enable(mdata->spi_clk);
778 	if (ret < 0) {
779 		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
780 		return ret;
781 	}
782 
783 	return 0;
784 }
785 #endif /* CONFIG_PM */
786 
787 static const struct dev_pm_ops mtk_spi_pm = {
788 	SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_suspend, mtk_spi_resume)
789 	SET_RUNTIME_PM_OPS(mtk_spi_runtime_suspend,
790 			   mtk_spi_runtime_resume, NULL)
791 };
792 
793 static struct platform_driver mtk_spi_driver = {
794 	.driver = {
795 		.name = "mtk-spi",
796 		.pm	= &mtk_spi_pm,
797 		.of_match_table = mtk_spi_of_match,
798 	},
799 	.probe = mtk_spi_probe,
800 	.remove = mtk_spi_remove,
801 };
802 
803 module_platform_driver(mtk_spi_driver);
804 
805 MODULE_DESCRIPTION("MTK SPI Controller driver");
806 MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
807 MODULE_LICENSE("GPL v2");
808 MODULE_ALIAS("platform:mtk-spi");
809