xref: /openbmc/linux/drivers/spi/spi-mt65xx.c (revision 82e6fdd6)
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 	struct scatterlist *tx_sgl, *rx_sgl;
102 	u32 tx_sgl_len, rx_sgl_len;
103 	const struct mtk_spi_compatible *dev_comp;
104 };
105 
106 static const struct mtk_spi_compatible mtk_common_compat;
107 
108 static const struct mtk_spi_compatible mt2712_compat = {
109 	.must_tx = true,
110 };
111 
112 static const struct mtk_spi_compatible mt7622_compat = {
113 	.must_tx = true,
114 	.enhance_timing = true,
115 };
116 
117 static const struct mtk_spi_compatible mt8173_compat = {
118 	.need_pad_sel = true,
119 	.must_tx = true,
120 };
121 
122 /*
123  * A piece of default chip info unless the platform
124  * supplies it.
125  */
126 static const struct mtk_chip_config mtk_default_chip_info = {
127 	.rx_mlsb = 1,
128 	.tx_mlsb = 1,
129 	.cs_pol = 0,
130 	.sample_sel = 0,
131 };
132 
133 static const struct of_device_id mtk_spi_of_match[] = {
134 	{ .compatible = "mediatek,mt2701-spi",
135 		.data = (void *)&mtk_common_compat,
136 	},
137 	{ .compatible = "mediatek,mt2712-spi",
138 		.data = (void *)&mt2712_compat,
139 	},
140 	{ .compatible = "mediatek,mt6589-spi",
141 		.data = (void *)&mtk_common_compat,
142 	},
143 	{ .compatible = "mediatek,mt7622-spi",
144 		.data = (void *)&mt7622_compat,
145 	},
146 	{ .compatible = "mediatek,mt8135-spi",
147 		.data = (void *)&mtk_common_compat,
148 	},
149 	{ .compatible = "mediatek,mt8173-spi",
150 		.data = (void *)&mt8173_compat,
151 	},
152 	{}
153 };
154 MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
155 
156 static void mtk_spi_reset(struct mtk_spi *mdata)
157 {
158 	u32 reg_val;
159 
160 	/* set the software reset bit in SPI_CMD_REG. */
161 	reg_val = readl(mdata->base + SPI_CMD_REG);
162 	reg_val |= SPI_CMD_RST;
163 	writel(reg_val, mdata->base + SPI_CMD_REG);
164 
165 	reg_val = readl(mdata->base + SPI_CMD_REG);
166 	reg_val &= ~SPI_CMD_RST;
167 	writel(reg_val, mdata->base + SPI_CMD_REG);
168 }
169 
170 static int mtk_spi_prepare_message(struct spi_master *master,
171 				   struct spi_message *msg)
172 {
173 	u16 cpha, cpol;
174 	u32 reg_val;
175 	struct spi_device *spi = msg->spi;
176 	struct mtk_chip_config *chip_config = spi->controller_data;
177 	struct mtk_spi *mdata = spi_master_get_devdata(master);
178 
179 	cpha = spi->mode & SPI_CPHA ? 1 : 0;
180 	cpol = spi->mode & SPI_CPOL ? 1 : 0;
181 
182 	reg_val = readl(mdata->base + SPI_CMD_REG);
183 	if (cpha)
184 		reg_val |= SPI_CMD_CPHA;
185 	else
186 		reg_val &= ~SPI_CMD_CPHA;
187 	if (cpol)
188 		reg_val |= SPI_CMD_CPOL;
189 	else
190 		reg_val &= ~SPI_CMD_CPOL;
191 
192 	/* set the mlsbx and mlsbtx */
193 	if (chip_config->tx_mlsb)
194 		reg_val |= SPI_CMD_TXMSBF;
195 	else
196 		reg_val &= ~SPI_CMD_TXMSBF;
197 	if (chip_config->rx_mlsb)
198 		reg_val |= SPI_CMD_RXMSBF;
199 	else
200 		reg_val &= ~SPI_CMD_RXMSBF;
201 
202 	/* set the tx/rx endian */
203 #ifdef __LITTLE_ENDIAN
204 	reg_val &= ~SPI_CMD_TX_ENDIAN;
205 	reg_val &= ~SPI_CMD_RX_ENDIAN;
206 #else
207 	reg_val |= SPI_CMD_TX_ENDIAN;
208 	reg_val |= SPI_CMD_RX_ENDIAN;
209 #endif
210 
211 	if (mdata->dev_comp->enhance_timing) {
212 		if (chip_config->cs_pol)
213 			reg_val |= SPI_CMD_CS_POL;
214 		else
215 			reg_val &= ~SPI_CMD_CS_POL;
216 		if (chip_config->sample_sel)
217 			reg_val |= SPI_CMD_SAMPLE_SEL;
218 		else
219 			reg_val &= ~SPI_CMD_SAMPLE_SEL;
220 	}
221 
222 	/* set finish and pause interrupt always enable */
223 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;
224 
225 	/* disable dma mode */
226 	reg_val &= ~(SPI_CMD_TX_DMA | SPI_CMD_RX_DMA);
227 
228 	/* disable deassert mode */
229 	reg_val &= ~SPI_CMD_DEASSERT;
230 
231 	writel(reg_val, mdata->base + SPI_CMD_REG);
232 
233 	/* pad select */
234 	if (mdata->dev_comp->need_pad_sel)
235 		writel(mdata->pad_sel[spi->chip_select],
236 		       mdata->base + SPI_PAD_SEL_REG);
237 
238 	return 0;
239 }
240 
241 static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
242 {
243 	u32 reg_val;
244 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
245 
246 	reg_val = readl(mdata->base + SPI_CMD_REG);
247 	if (!enable) {
248 		reg_val |= SPI_CMD_PAUSE_EN;
249 		writel(reg_val, mdata->base + SPI_CMD_REG);
250 	} else {
251 		reg_val &= ~SPI_CMD_PAUSE_EN;
252 		writel(reg_val, mdata->base + SPI_CMD_REG);
253 		mdata->state = MTK_SPI_IDLE;
254 		mtk_spi_reset(mdata);
255 	}
256 }
257 
258 static void mtk_spi_prepare_transfer(struct spi_master *master,
259 				     struct spi_transfer *xfer)
260 {
261 	u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0;
262 	struct mtk_spi *mdata = spi_master_get_devdata(master);
263 
264 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
265 	if (xfer->speed_hz < spi_clk_hz / 2)
266 		div = DIV_ROUND_UP(spi_clk_hz, xfer->speed_hz);
267 	else
268 		div = 1;
269 
270 	sck_time = (div + 1) / 2;
271 	cs_time = sck_time * 2;
272 
273 	if (mdata->dev_comp->enhance_timing) {
274 		reg_val |= (((sck_time - 1) & 0xffff)
275 			   << SPI_CFG0_SCK_HIGH_OFFSET);
276 		reg_val |= (((sck_time - 1) & 0xffff)
277 			   << SPI_ADJUST_CFG0_SCK_LOW_OFFSET);
278 		writel(reg_val, mdata->base + SPI_CFG2_REG);
279 		reg_val |= (((cs_time - 1) & 0xffff)
280 			   << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
281 		reg_val |= (((cs_time - 1) & 0xffff)
282 			   << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
283 		writel(reg_val, mdata->base + SPI_CFG0_REG);
284 	} else {
285 		reg_val |= (((sck_time - 1) & 0xff)
286 			   << SPI_CFG0_SCK_HIGH_OFFSET);
287 		reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
288 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
289 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
290 		writel(reg_val, mdata->base + SPI_CFG0_REG);
291 	}
292 
293 	reg_val = readl(mdata->base + SPI_CFG1_REG);
294 	reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
295 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
296 	writel(reg_val, mdata->base + SPI_CFG1_REG);
297 }
298 
299 static void mtk_spi_setup_packet(struct spi_master *master)
300 {
301 	u32 packet_size, packet_loop, reg_val;
302 	struct mtk_spi *mdata = spi_master_get_devdata(master);
303 
304 	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
305 	packet_loop = mdata->xfer_len / packet_size;
306 
307 	reg_val = readl(mdata->base + SPI_CFG1_REG);
308 	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
309 	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
310 	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
311 	writel(reg_val, mdata->base + SPI_CFG1_REG);
312 }
313 
314 static void mtk_spi_enable_transfer(struct spi_master *master)
315 {
316 	u32 cmd;
317 	struct mtk_spi *mdata = spi_master_get_devdata(master);
318 
319 	cmd = readl(mdata->base + SPI_CMD_REG);
320 	if (mdata->state == MTK_SPI_IDLE)
321 		cmd |= SPI_CMD_ACT;
322 	else
323 		cmd |= SPI_CMD_RESUME;
324 	writel(cmd, mdata->base + SPI_CMD_REG);
325 }
326 
327 static int mtk_spi_get_mult_delta(u32 xfer_len)
328 {
329 	u32 mult_delta;
330 
331 	if (xfer_len > MTK_SPI_PACKET_SIZE)
332 		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
333 	else
334 		mult_delta = 0;
335 
336 	return mult_delta;
337 }
338 
339 static void mtk_spi_update_mdata_len(struct spi_master *master)
340 {
341 	int mult_delta;
342 	struct mtk_spi *mdata = spi_master_get_devdata(master);
343 
344 	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
345 		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
346 			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
347 			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
348 			mdata->rx_sgl_len = mult_delta;
349 			mdata->tx_sgl_len -= mdata->xfer_len;
350 		} else {
351 			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
352 			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
353 			mdata->tx_sgl_len = mult_delta;
354 			mdata->rx_sgl_len -= mdata->xfer_len;
355 		}
356 	} else if (mdata->tx_sgl_len) {
357 		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
358 		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
359 		mdata->tx_sgl_len = mult_delta;
360 	} else if (mdata->rx_sgl_len) {
361 		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
362 		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
363 		mdata->rx_sgl_len = mult_delta;
364 	}
365 }
366 
367 static void mtk_spi_setup_dma_addr(struct spi_master *master,
368 				   struct spi_transfer *xfer)
369 {
370 	struct mtk_spi *mdata = spi_master_get_devdata(master);
371 
372 	if (mdata->tx_sgl)
373 		writel(xfer->tx_dma, mdata->base + SPI_TX_SRC_REG);
374 	if (mdata->rx_sgl)
375 		writel(xfer->rx_dma, mdata->base + SPI_RX_DST_REG);
376 }
377 
378 static int mtk_spi_fifo_transfer(struct spi_master *master,
379 				 struct spi_device *spi,
380 				 struct spi_transfer *xfer)
381 {
382 	int cnt, remainder;
383 	u32 reg_val;
384 	struct mtk_spi *mdata = spi_master_get_devdata(master);
385 
386 	mdata->cur_transfer = xfer;
387 	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
388 	mtk_spi_prepare_transfer(master, xfer);
389 	mtk_spi_setup_packet(master);
390 
391 	cnt = xfer->len / 4;
392 	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
393 
394 	remainder = xfer->len % 4;
395 	if (remainder > 0) {
396 		reg_val = 0;
397 		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
398 		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
399 	}
400 
401 	mtk_spi_enable_transfer(master);
402 
403 	return 1;
404 }
405 
406 static int mtk_spi_dma_transfer(struct spi_master *master,
407 				struct spi_device *spi,
408 				struct spi_transfer *xfer)
409 {
410 	int cmd;
411 	struct mtk_spi *mdata = spi_master_get_devdata(master);
412 
413 	mdata->tx_sgl = NULL;
414 	mdata->rx_sgl = NULL;
415 	mdata->tx_sgl_len = 0;
416 	mdata->rx_sgl_len = 0;
417 	mdata->cur_transfer = xfer;
418 
419 	mtk_spi_prepare_transfer(master, xfer);
420 
421 	cmd = readl(mdata->base + SPI_CMD_REG);
422 	if (xfer->tx_buf)
423 		cmd |= SPI_CMD_TX_DMA;
424 	if (xfer->rx_buf)
425 		cmd |= SPI_CMD_RX_DMA;
426 	writel(cmd, mdata->base + SPI_CMD_REG);
427 
428 	if (xfer->tx_buf)
429 		mdata->tx_sgl = xfer->tx_sg.sgl;
430 	if (xfer->rx_buf)
431 		mdata->rx_sgl = xfer->rx_sg.sgl;
432 
433 	if (mdata->tx_sgl) {
434 		xfer->tx_dma = sg_dma_address(mdata->tx_sgl);
435 		mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
436 	}
437 	if (mdata->rx_sgl) {
438 		xfer->rx_dma = sg_dma_address(mdata->rx_sgl);
439 		mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
440 	}
441 
442 	mtk_spi_update_mdata_len(master);
443 	mtk_spi_setup_packet(master);
444 	mtk_spi_setup_dma_addr(master, xfer);
445 	mtk_spi_enable_transfer(master);
446 
447 	return 1;
448 }
449 
450 static int mtk_spi_transfer_one(struct spi_master *master,
451 				struct spi_device *spi,
452 				struct spi_transfer *xfer)
453 {
454 	if (master->can_dma(master, spi, xfer))
455 		return mtk_spi_dma_transfer(master, spi, xfer);
456 	else
457 		return mtk_spi_fifo_transfer(master, spi, xfer);
458 }
459 
460 static bool mtk_spi_can_dma(struct spi_master *master,
461 			    struct spi_device *spi,
462 			    struct spi_transfer *xfer)
463 {
464 	/* Buffers for DMA transactions must be 4-byte aligned */
465 	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
466 		(unsigned long)xfer->tx_buf % 4 == 0 &&
467 		(unsigned long)xfer->rx_buf % 4 == 0);
468 }
469 
470 static int mtk_spi_setup(struct spi_device *spi)
471 {
472 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
473 
474 	if (!spi->controller_data)
475 		spi->controller_data = (void *)&mtk_default_chip_info;
476 
477 	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
478 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
479 
480 	return 0;
481 }
482 
483 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
484 {
485 	u32 cmd, reg_val, cnt, remainder;
486 	struct spi_master *master = dev_id;
487 	struct mtk_spi *mdata = spi_master_get_devdata(master);
488 	struct spi_transfer *trans = mdata->cur_transfer;
489 
490 	reg_val = readl(mdata->base + SPI_STATUS0_REG);
491 	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
492 		mdata->state = MTK_SPI_PAUSED;
493 	else
494 		mdata->state = MTK_SPI_IDLE;
495 
496 	if (!master->can_dma(master, master->cur_msg->spi, trans)) {
497 		if (trans->rx_buf) {
498 			cnt = mdata->xfer_len / 4;
499 			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
500 				     trans->rx_buf, cnt);
501 			remainder = mdata->xfer_len % 4;
502 			if (remainder > 0) {
503 				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
504 				memcpy(trans->rx_buf + (cnt * 4),
505 					&reg_val, remainder);
506 			}
507 		}
508 
509 		trans->len -= mdata->xfer_len;
510 		if (!trans->len) {
511 			spi_finalize_current_transfer(master);
512 			return IRQ_HANDLED;
513 		}
514 
515 		if (trans->tx_buf)
516 			trans->tx_buf += mdata->xfer_len;
517 		if (trans->rx_buf)
518 			trans->rx_buf += mdata->xfer_len;
519 
520 		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, trans->len);
521 		mtk_spi_setup_packet(master);
522 
523 		cnt = trans->len / 4;
524 		iowrite32_rep(mdata->base + SPI_TX_DATA_REG, trans->tx_buf, cnt);
525 
526 		remainder = trans->len % 4;
527 		if (remainder > 0) {
528 			reg_val = 0;
529 			memcpy(&reg_val, trans->tx_buf + (cnt * 4), remainder);
530 			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
531 		}
532 
533 		mtk_spi_enable_transfer(master);
534 
535 		return IRQ_HANDLED;
536 	}
537 
538 	if (mdata->tx_sgl)
539 		trans->tx_dma += mdata->xfer_len;
540 	if (mdata->rx_sgl)
541 		trans->rx_dma += mdata->xfer_len;
542 
543 	if (mdata->tx_sgl && (mdata->tx_sgl_len == 0)) {
544 		mdata->tx_sgl = sg_next(mdata->tx_sgl);
545 		if (mdata->tx_sgl) {
546 			trans->tx_dma = sg_dma_address(mdata->tx_sgl);
547 			mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
548 		}
549 	}
550 	if (mdata->rx_sgl && (mdata->rx_sgl_len == 0)) {
551 		mdata->rx_sgl = sg_next(mdata->rx_sgl);
552 		if (mdata->rx_sgl) {
553 			trans->rx_dma = sg_dma_address(mdata->rx_sgl);
554 			mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
555 		}
556 	}
557 
558 	if (!mdata->tx_sgl && !mdata->rx_sgl) {
559 		/* spi disable dma */
560 		cmd = readl(mdata->base + SPI_CMD_REG);
561 		cmd &= ~SPI_CMD_TX_DMA;
562 		cmd &= ~SPI_CMD_RX_DMA;
563 		writel(cmd, mdata->base + SPI_CMD_REG);
564 
565 		spi_finalize_current_transfer(master);
566 		return IRQ_HANDLED;
567 	}
568 
569 	mtk_spi_update_mdata_len(master);
570 	mtk_spi_setup_packet(master);
571 	mtk_spi_setup_dma_addr(master, trans);
572 	mtk_spi_enable_transfer(master);
573 
574 	return IRQ_HANDLED;
575 }
576 
577 static int mtk_spi_probe(struct platform_device *pdev)
578 {
579 	struct spi_master *master;
580 	struct mtk_spi *mdata;
581 	const struct of_device_id *of_id;
582 	struct resource *res;
583 	int i, irq, ret;
584 
585 	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
586 	if (!master) {
587 		dev_err(&pdev->dev, "failed to alloc spi master\n");
588 		return -ENOMEM;
589 	}
590 
591 	master->auto_runtime_pm = true;
592 	master->dev.of_node = pdev->dev.of_node;
593 	master->mode_bits = SPI_CPOL | SPI_CPHA;
594 
595 	master->set_cs = mtk_spi_set_cs;
596 	master->prepare_message = mtk_spi_prepare_message;
597 	master->transfer_one = mtk_spi_transfer_one;
598 	master->can_dma = mtk_spi_can_dma;
599 	master->setup = mtk_spi_setup;
600 
601 	of_id = of_match_node(mtk_spi_of_match, pdev->dev.of_node);
602 	if (!of_id) {
603 		dev_err(&pdev->dev, "failed to probe of_node\n");
604 		ret = -EINVAL;
605 		goto err_put_master;
606 	}
607 
608 	mdata = spi_master_get_devdata(master);
609 	mdata->dev_comp = of_id->data;
610 	if (mdata->dev_comp->must_tx)
611 		master->flags = SPI_MASTER_MUST_TX;
612 
613 	if (mdata->dev_comp->need_pad_sel) {
614 		mdata->pad_num = of_property_count_u32_elems(
615 			pdev->dev.of_node,
616 			"mediatek,pad-select");
617 		if (mdata->pad_num < 0) {
618 			dev_err(&pdev->dev,
619 				"No 'mediatek,pad-select' property\n");
620 			ret = -EINVAL;
621 			goto err_put_master;
622 		}
623 
624 		mdata->pad_sel = devm_kmalloc_array(&pdev->dev, mdata->pad_num,
625 						    sizeof(u32), GFP_KERNEL);
626 		if (!mdata->pad_sel) {
627 			ret = -ENOMEM;
628 			goto err_put_master;
629 		}
630 
631 		for (i = 0; i < mdata->pad_num; i++) {
632 			of_property_read_u32_index(pdev->dev.of_node,
633 						   "mediatek,pad-select",
634 						   i, &mdata->pad_sel[i]);
635 			if (mdata->pad_sel[i] > MT8173_SPI_MAX_PAD_SEL) {
636 				dev_err(&pdev->dev, "wrong pad-sel[%d]: %u\n",
637 					i, mdata->pad_sel[i]);
638 				ret = -EINVAL;
639 				goto err_put_master;
640 			}
641 		}
642 	}
643 
644 	platform_set_drvdata(pdev, master);
645 
646 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
647 	if (!res) {
648 		ret = -ENODEV;
649 		dev_err(&pdev->dev, "failed to determine base address\n");
650 		goto err_put_master;
651 	}
652 
653 	mdata->base = devm_ioremap_resource(&pdev->dev, res);
654 	if (IS_ERR(mdata->base)) {
655 		ret = PTR_ERR(mdata->base);
656 		goto err_put_master;
657 	}
658 
659 	irq = platform_get_irq(pdev, 0);
660 	if (irq < 0) {
661 		dev_err(&pdev->dev, "failed to get irq (%d)\n", irq);
662 		ret = irq;
663 		goto err_put_master;
664 	}
665 
666 	if (!pdev->dev.dma_mask)
667 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
668 
669 	ret = devm_request_irq(&pdev->dev, irq, mtk_spi_interrupt,
670 			       IRQF_TRIGGER_NONE, dev_name(&pdev->dev), master);
671 	if (ret) {
672 		dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
673 		goto err_put_master;
674 	}
675 
676 	mdata->parent_clk = devm_clk_get(&pdev->dev, "parent-clk");
677 	if (IS_ERR(mdata->parent_clk)) {
678 		ret = PTR_ERR(mdata->parent_clk);
679 		dev_err(&pdev->dev, "failed to get parent-clk: %d\n", ret);
680 		goto err_put_master;
681 	}
682 
683 	mdata->sel_clk = devm_clk_get(&pdev->dev, "sel-clk");
684 	if (IS_ERR(mdata->sel_clk)) {
685 		ret = PTR_ERR(mdata->sel_clk);
686 		dev_err(&pdev->dev, "failed to get sel-clk: %d\n", ret);
687 		goto err_put_master;
688 	}
689 
690 	mdata->spi_clk = devm_clk_get(&pdev->dev, "spi-clk");
691 	if (IS_ERR(mdata->spi_clk)) {
692 		ret = PTR_ERR(mdata->spi_clk);
693 		dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
694 		goto err_put_master;
695 	}
696 
697 	ret = clk_prepare_enable(mdata->spi_clk);
698 	if (ret < 0) {
699 		dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
700 		goto err_put_master;
701 	}
702 
703 	ret = clk_set_parent(mdata->sel_clk, mdata->parent_clk);
704 	if (ret < 0) {
705 		dev_err(&pdev->dev, "failed to clk_set_parent (%d)\n", ret);
706 		clk_disable_unprepare(mdata->spi_clk);
707 		goto err_put_master;
708 	}
709 
710 	clk_disable_unprepare(mdata->spi_clk);
711 
712 	pm_runtime_enable(&pdev->dev);
713 
714 	ret = devm_spi_register_master(&pdev->dev, master);
715 	if (ret) {
716 		dev_err(&pdev->dev, "failed to register master (%d)\n", ret);
717 		goto err_disable_runtime_pm;
718 	}
719 
720 	if (mdata->dev_comp->need_pad_sel) {
721 		if (mdata->pad_num != master->num_chipselect) {
722 			dev_err(&pdev->dev,
723 				"pad_num does not match num_chipselect(%d != %d)\n",
724 				mdata->pad_num, master->num_chipselect);
725 			ret = -EINVAL;
726 			goto err_disable_runtime_pm;
727 		}
728 
729 		if (!master->cs_gpios && master->num_chipselect > 1) {
730 			dev_err(&pdev->dev,
731 				"cs_gpios not specified and num_chipselect > 1\n");
732 			ret = -EINVAL;
733 			goto err_disable_runtime_pm;
734 		}
735 
736 		if (master->cs_gpios) {
737 			for (i = 0; i < master->num_chipselect; i++) {
738 				ret = devm_gpio_request(&pdev->dev,
739 							master->cs_gpios[i],
740 							dev_name(&pdev->dev));
741 				if (ret) {
742 					dev_err(&pdev->dev,
743 						"can't get CS GPIO %i\n", i);
744 					goto err_disable_runtime_pm;
745 				}
746 			}
747 		}
748 	}
749 
750 	return 0;
751 
752 err_disable_runtime_pm:
753 	pm_runtime_disable(&pdev->dev);
754 err_put_master:
755 	spi_master_put(master);
756 
757 	return ret;
758 }
759 
760 static int mtk_spi_remove(struct platform_device *pdev)
761 {
762 	struct spi_master *master = platform_get_drvdata(pdev);
763 	struct mtk_spi *mdata = spi_master_get_devdata(master);
764 
765 	pm_runtime_disable(&pdev->dev);
766 
767 	mtk_spi_reset(mdata);
768 
769 	return 0;
770 }
771 
772 #ifdef CONFIG_PM_SLEEP
773 static int mtk_spi_suspend(struct device *dev)
774 {
775 	int ret;
776 	struct spi_master *master = dev_get_drvdata(dev);
777 	struct mtk_spi *mdata = spi_master_get_devdata(master);
778 
779 	ret = spi_master_suspend(master);
780 	if (ret)
781 		return ret;
782 
783 	if (!pm_runtime_suspended(dev))
784 		clk_disable_unprepare(mdata->spi_clk);
785 
786 	return ret;
787 }
788 
789 static int mtk_spi_resume(struct device *dev)
790 {
791 	int ret;
792 	struct spi_master *master = dev_get_drvdata(dev);
793 	struct mtk_spi *mdata = spi_master_get_devdata(master);
794 
795 	if (!pm_runtime_suspended(dev)) {
796 		ret = clk_prepare_enable(mdata->spi_clk);
797 		if (ret < 0) {
798 			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
799 			return ret;
800 		}
801 	}
802 
803 	ret = spi_master_resume(master);
804 	if (ret < 0)
805 		clk_disable_unprepare(mdata->spi_clk);
806 
807 	return ret;
808 }
809 #endif /* CONFIG_PM_SLEEP */
810 
811 #ifdef CONFIG_PM
812 static int mtk_spi_runtime_suspend(struct device *dev)
813 {
814 	struct spi_master *master = dev_get_drvdata(dev);
815 	struct mtk_spi *mdata = spi_master_get_devdata(master);
816 
817 	clk_disable_unprepare(mdata->spi_clk);
818 
819 	return 0;
820 }
821 
822 static int mtk_spi_runtime_resume(struct device *dev)
823 {
824 	struct spi_master *master = dev_get_drvdata(dev);
825 	struct mtk_spi *mdata = spi_master_get_devdata(master);
826 	int ret;
827 
828 	ret = clk_prepare_enable(mdata->spi_clk);
829 	if (ret < 0) {
830 		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
831 		return ret;
832 	}
833 
834 	return 0;
835 }
836 #endif /* CONFIG_PM */
837 
838 static const struct dev_pm_ops mtk_spi_pm = {
839 	SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_suspend, mtk_spi_resume)
840 	SET_RUNTIME_PM_OPS(mtk_spi_runtime_suspend,
841 			   mtk_spi_runtime_resume, NULL)
842 };
843 
844 static struct platform_driver mtk_spi_driver = {
845 	.driver = {
846 		.name = "mtk-spi",
847 		.pm	= &mtk_spi_pm,
848 		.of_match_table = mtk_spi_of_match,
849 	},
850 	.probe = mtk_spi_probe,
851 	.remove = mtk_spi_remove,
852 };
853 
854 module_platform_driver(mtk_spi_driver);
855 
856 MODULE_DESCRIPTION("MTK SPI Controller driver");
857 MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
858 MODULE_LICENSE("GPL v2");
859 MODULE_ALIAS("platform:mtk-spi");
860