xref: /openbmc/linux/drivers/spi/spi-mt65xx.c (revision 8781e5df)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015 MediaTek Inc.
4  * Author: Leilk Liu <leilk.liu@mediatek.com>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/device.h>
9 #include <linux/err.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/ioport.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_gpio.h>
16 #include <linux/platform_device.h>
17 #include <linux/platform_data/spi-mt65xx.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/spi/spi.h>
20 #include <linux/dma-mapping.h>
21 
22 #define SPI_CFG0_REG                      0x0000
23 #define SPI_CFG1_REG                      0x0004
24 #define SPI_TX_SRC_REG                    0x0008
25 #define SPI_RX_DST_REG                    0x000c
26 #define SPI_TX_DATA_REG                   0x0010
27 #define SPI_RX_DATA_REG                   0x0014
28 #define SPI_CMD_REG                       0x0018
29 #define SPI_STATUS0_REG                   0x001c
30 #define SPI_PAD_SEL_REG                   0x0024
31 #define SPI_CFG2_REG                      0x0028
32 #define SPI_TX_SRC_REG_64                 0x002c
33 #define SPI_RX_DST_REG_64                 0x0030
34 
35 #define SPI_CFG0_SCK_HIGH_OFFSET          0
36 #define SPI_CFG0_SCK_LOW_OFFSET           8
37 #define SPI_CFG0_CS_HOLD_OFFSET           16
38 #define SPI_CFG0_CS_SETUP_OFFSET          24
39 #define SPI_ADJUST_CFG0_SCK_LOW_OFFSET    16
40 #define SPI_ADJUST_CFG0_CS_HOLD_OFFSET    0
41 #define SPI_ADJUST_CFG0_CS_SETUP_OFFSET   16
42 
43 #define SPI_CFG1_CS_IDLE_OFFSET           0
44 #define SPI_CFG1_PACKET_LOOP_OFFSET       8
45 #define SPI_CFG1_PACKET_LENGTH_OFFSET     16
46 #define SPI_CFG1_GET_TICK_DLY_OFFSET      30
47 
48 #define SPI_CFG1_CS_IDLE_MASK             0xff
49 #define SPI_CFG1_PACKET_LOOP_MASK         0xff00
50 #define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
51 
52 #define SPI_CMD_ACT                  BIT(0)
53 #define SPI_CMD_RESUME               BIT(1)
54 #define SPI_CMD_RST                  BIT(2)
55 #define SPI_CMD_PAUSE_EN             BIT(4)
56 #define SPI_CMD_DEASSERT             BIT(5)
57 #define SPI_CMD_SAMPLE_SEL           BIT(6)
58 #define SPI_CMD_CS_POL               BIT(7)
59 #define SPI_CMD_CPHA                 BIT(8)
60 #define SPI_CMD_CPOL                 BIT(9)
61 #define SPI_CMD_RX_DMA               BIT(10)
62 #define SPI_CMD_TX_DMA               BIT(11)
63 #define SPI_CMD_TXMSBF               BIT(12)
64 #define SPI_CMD_RXMSBF               BIT(13)
65 #define SPI_CMD_RX_ENDIAN            BIT(14)
66 #define SPI_CMD_TX_ENDIAN            BIT(15)
67 #define SPI_CMD_FINISH_IE            BIT(16)
68 #define SPI_CMD_PAUSE_IE             BIT(17)
69 
70 #define MT8173_SPI_MAX_PAD_SEL 3
71 
72 #define MTK_SPI_PAUSE_INT_STATUS 0x2
73 
74 #define MTK_SPI_IDLE 0
75 #define MTK_SPI_PAUSED 1
76 
77 #define MTK_SPI_MAX_FIFO_SIZE 32U
78 #define MTK_SPI_PACKET_SIZE 1024
79 #define MTK_SPI_32BITS_MASK  (0xffffffff)
80 
81 #define DMA_ADDR_EXT_BITS (36)
82 #define DMA_ADDR_DEF_BITS (32)
83 
84 struct mtk_spi_compatible {
85 	bool need_pad_sel;
86 	/* Must explicitly send dummy Tx bytes to do Rx only transfer */
87 	bool must_tx;
88 	/* some IC design adjust cfg register to enhance time accuracy */
89 	bool enhance_timing;
90 	/* some IC support DMA addr extension */
91 	bool dma_ext;
92 };
93 
94 struct mtk_spi {
95 	void __iomem *base;
96 	u32 state;
97 	int pad_num;
98 	u32 *pad_sel;
99 	struct clk *parent_clk, *sel_clk, *spi_clk;
100 	struct spi_transfer *cur_transfer;
101 	u32 xfer_len;
102 	u32 num_xfered;
103 	struct scatterlist *tx_sgl, *rx_sgl;
104 	u32 tx_sgl_len, rx_sgl_len;
105 	const struct mtk_spi_compatible *dev_comp;
106 };
107 
108 static const struct mtk_spi_compatible mtk_common_compat;
109 
110 static const struct mtk_spi_compatible mt2712_compat = {
111 	.must_tx = true,
112 };
113 
114 static const struct mtk_spi_compatible mt6765_compat = {
115 	.need_pad_sel = true,
116 	.must_tx = true,
117 	.enhance_timing = true,
118 	.dma_ext = true,
119 };
120 
121 static const struct mtk_spi_compatible mt7622_compat = {
122 	.must_tx = true,
123 	.enhance_timing = true,
124 };
125 
126 static const struct mtk_spi_compatible mt8173_compat = {
127 	.need_pad_sel = true,
128 	.must_tx = true,
129 };
130 
131 static const struct mtk_spi_compatible mt8183_compat = {
132 	.need_pad_sel = true,
133 	.must_tx = true,
134 	.enhance_timing = true,
135 };
136 
137 /*
138  * A piece of default chip info unless the platform
139  * supplies it.
140  */
141 static const struct mtk_chip_config mtk_default_chip_info = {
142 	.cs_pol = 0,
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 	{}
175 };
176 MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
177 
178 static void mtk_spi_reset(struct mtk_spi *mdata)
179 {
180 	u32 reg_val;
181 
182 	/* set the software reset bit in SPI_CMD_REG. */
183 	reg_val = readl(mdata->base + SPI_CMD_REG);
184 	reg_val |= SPI_CMD_RST;
185 	writel(reg_val, mdata->base + SPI_CMD_REG);
186 
187 	reg_val = readl(mdata->base + SPI_CMD_REG);
188 	reg_val &= ~SPI_CMD_RST;
189 	writel(reg_val, mdata->base + SPI_CMD_REG);
190 }
191 
192 static int mtk_spi_prepare_message(struct spi_master *master,
193 				   struct spi_message *msg)
194 {
195 	u16 cpha, cpol;
196 	u32 reg_val;
197 	struct spi_device *spi = msg->spi;
198 	struct mtk_chip_config *chip_config = spi->controller_data;
199 	struct mtk_spi *mdata = spi_master_get_devdata(master);
200 
201 	cpha = spi->mode & SPI_CPHA ? 1 : 0;
202 	cpol = spi->mode & SPI_CPOL ? 1 : 0;
203 
204 	reg_val = readl(mdata->base + SPI_CMD_REG);
205 	if (cpha)
206 		reg_val |= SPI_CMD_CPHA;
207 	else
208 		reg_val &= ~SPI_CMD_CPHA;
209 	if (cpol)
210 		reg_val |= SPI_CMD_CPOL;
211 	else
212 		reg_val &= ~SPI_CMD_CPOL;
213 
214 	/* set the mlsbx and mlsbtx */
215 	if (spi->mode & SPI_LSB_FIRST) {
216 		reg_val &= ~SPI_CMD_TXMSBF;
217 		reg_val &= ~SPI_CMD_RXMSBF;
218 	} else {
219 		reg_val |= SPI_CMD_TXMSBF;
220 		reg_val |= SPI_CMD_RXMSBF;
221 	}
222 
223 	/* set the tx/rx endian */
224 #ifdef __LITTLE_ENDIAN
225 	reg_val &= ~SPI_CMD_TX_ENDIAN;
226 	reg_val &= ~SPI_CMD_RX_ENDIAN;
227 #else
228 	reg_val |= SPI_CMD_TX_ENDIAN;
229 	reg_val |= SPI_CMD_RX_ENDIAN;
230 #endif
231 
232 	if (mdata->dev_comp->enhance_timing) {
233 		if (chip_config->cs_pol)
234 			reg_val |= SPI_CMD_CS_POL;
235 		else
236 			reg_val &= ~SPI_CMD_CS_POL;
237 		if (chip_config->sample_sel)
238 			reg_val |= SPI_CMD_SAMPLE_SEL;
239 		else
240 			reg_val &= ~SPI_CMD_SAMPLE_SEL;
241 	}
242 
243 	/* set finish and pause interrupt always enable */
244 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_IE;
245 
246 	/* disable dma mode */
247 	reg_val &= ~(SPI_CMD_TX_DMA | SPI_CMD_RX_DMA);
248 
249 	/* disable deassert mode */
250 	reg_val &= ~SPI_CMD_DEASSERT;
251 
252 	writel(reg_val, mdata->base + SPI_CMD_REG);
253 
254 	/* pad select */
255 	if (mdata->dev_comp->need_pad_sel)
256 		writel(mdata->pad_sel[spi->chip_select],
257 		       mdata->base + SPI_PAD_SEL_REG);
258 
259 	return 0;
260 }
261 
262 static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
263 {
264 	u32 reg_val;
265 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
266 
267 	reg_val = readl(mdata->base + SPI_CMD_REG);
268 	if (!enable) {
269 		reg_val |= SPI_CMD_PAUSE_EN;
270 		writel(reg_val, mdata->base + SPI_CMD_REG);
271 	} else {
272 		reg_val &= ~SPI_CMD_PAUSE_EN;
273 		writel(reg_val, mdata->base + SPI_CMD_REG);
274 		mdata->state = MTK_SPI_IDLE;
275 		mtk_spi_reset(mdata);
276 	}
277 }
278 
279 static void mtk_spi_prepare_transfer(struct spi_master *master,
280 				     struct spi_transfer *xfer)
281 {
282 	u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0;
283 	struct mtk_spi *mdata = spi_master_get_devdata(master);
284 
285 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
286 	if (xfer->speed_hz < spi_clk_hz / 2)
287 		div = DIV_ROUND_UP(spi_clk_hz, xfer->speed_hz);
288 	else
289 		div = 1;
290 
291 	sck_time = (div + 1) / 2;
292 	cs_time = sck_time * 2;
293 
294 	if (mdata->dev_comp->enhance_timing) {
295 		reg_val |= (((sck_time - 1) & 0xffff)
296 			   << SPI_CFG0_SCK_HIGH_OFFSET);
297 		reg_val |= (((sck_time - 1) & 0xffff)
298 			   << SPI_ADJUST_CFG0_SCK_LOW_OFFSET);
299 		writel(reg_val, mdata->base + SPI_CFG2_REG);
300 		reg_val |= (((cs_time - 1) & 0xffff)
301 			   << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
302 		reg_val |= (((cs_time - 1) & 0xffff)
303 			   << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
304 		writel(reg_val, mdata->base + SPI_CFG0_REG);
305 	} else {
306 		reg_val |= (((sck_time - 1) & 0xff)
307 			   << SPI_CFG0_SCK_HIGH_OFFSET);
308 		reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
309 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
310 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
311 		writel(reg_val, mdata->base + SPI_CFG0_REG);
312 	}
313 
314 	reg_val = readl(mdata->base + SPI_CFG1_REG);
315 	reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
316 	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
317 	writel(reg_val, mdata->base + SPI_CFG1_REG);
318 }
319 
320 static void mtk_spi_setup_packet(struct spi_master *master)
321 {
322 	u32 packet_size, packet_loop, reg_val;
323 	struct mtk_spi *mdata = spi_master_get_devdata(master);
324 
325 	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
326 	packet_loop = mdata->xfer_len / packet_size;
327 
328 	reg_val = readl(mdata->base + SPI_CFG1_REG);
329 	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
330 	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
331 	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
332 	writel(reg_val, mdata->base + SPI_CFG1_REG);
333 }
334 
335 static void mtk_spi_enable_transfer(struct spi_master *master)
336 {
337 	u32 cmd;
338 	struct mtk_spi *mdata = spi_master_get_devdata(master);
339 
340 	cmd = readl(mdata->base + SPI_CMD_REG);
341 	if (mdata->state == MTK_SPI_IDLE)
342 		cmd |= SPI_CMD_ACT;
343 	else
344 		cmd |= SPI_CMD_RESUME;
345 	writel(cmd, mdata->base + SPI_CMD_REG);
346 }
347 
348 static int mtk_spi_get_mult_delta(u32 xfer_len)
349 {
350 	u32 mult_delta;
351 
352 	if (xfer_len > MTK_SPI_PACKET_SIZE)
353 		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
354 	else
355 		mult_delta = 0;
356 
357 	return mult_delta;
358 }
359 
360 static void mtk_spi_update_mdata_len(struct spi_master *master)
361 {
362 	int mult_delta;
363 	struct mtk_spi *mdata = spi_master_get_devdata(master);
364 
365 	if (mdata->tx_sgl_len && mdata->rx_sgl_len) {
366 		if (mdata->tx_sgl_len > mdata->rx_sgl_len) {
367 			mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
368 			mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
369 			mdata->rx_sgl_len = mult_delta;
370 			mdata->tx_sgl_len -= mdata->xfer_len;
371 		} else {
372 			mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
373 			mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
374 			mdata->tx_sgl_len = mult_delta;
375 			mdata->rx_sgl_len -= mdata->xfer_len;
376 		}
377 	} else if (mdata->tx_sgl_len) {
378 		mult_delta = mtk_spi_get_mult_delta(mdata->tx_sgl_len);
379 		mdata->xfer_len = mdata->tx_sgl_len - mult_delta;
380 		mdata->tx_sgl_len = mult_delta;
381 	} else if (mdata->rx_sgl_len) {
382 		mult_delta = mtk_spi_get_mult_delta(mdata->rx_sgl_len);
383 		mdata->xfer_len = mdata->rx_sgl_len - mult_delta;
384 		mdata->rx_sgl_len = mult_delta;
385 	}
386 }
387 
388 static void mtk_spi_setup_dma_addr(struct spi_master *master,
389 				   struct spi_transfer *xfer)
390 {
391 	struct mtk_spi *mdata = spi_master_get_devdata(master);
392 
393 	if (mdata->tx_sgl) {
394 		writel((u32)(xfer->tx_dma & MTK_SPI_32BITS_MASK),
395 		       mdata->base + SPI_TX_SRC_REG);
396 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
397 		if (mdata->dev_comp->dma_ext)
398 			writel((u32)(xfer->tx_dma >> 32),
399 			       mdata->base + SPI_TX_SRC_REG_64);
400 #endif
401 	}
402 
403 	if (mdata->rx_sgl) {
404 		writel((u32)(xfer->rx_dma & MTK_SPI_32BITS_MASK),
405 		       mdata->base + SPI_RX_DST_REG);
406 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
407 		if (mdata->dev_comp->dma_ext)
408 			writel((u32)(xfer->rx_dma >> 32),
409 			       mdata->base + SPI_RX_DST_REG_64);
410 #endif
411 	}
412 }
413 
414 static int mtk_spi_fifo_transfer(struct spi_master *master,
415 				 struct spi_device *spi,
416 				 struct spi_transfer *xfer)
417 {
418 	int cnt, remainder;
419 	u32 reg_val;
420 	struct mtk_spi *mdata = spi_master_get_devdata(master);
421 
422 	mdata->cur_transfer = xfer;
423 	mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, xfer->len);
424 	mdata->num_xfered = 0;
425 	mtk_spi_prepare_transfer(master, xfer);
426 	mtk_spi_setup_packet(master);
427 
428 	cnt = xfer->len / 4;
429 	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
430 
431 	remainder = xfer->len % 4;
432 	if (remainder > 0) {
433 		reg_val = 0;
434 		memcpy(&reg_val, xfer->tx_buf + (cnt * 4), remainder);
435 		writel(reg_val, mdata->base + SPI_TX_DATA_REG);
436 	}
437 
438 	mtk_spi_enable_transfer(master);
439 
440 	return 1;
441 }
442 
443 static int mtk_spi_dma_transfer(struct spi_master *master,
444 				struct spi_device *spi,
445 				struct spi_transfer *xfer)
446 {
447 	int cmd;
448 	struct mtk_spi *mdata = spi_master_get_devdata(master);
449 
450 	mdata->tx_sgl = NULL;
451 	mdata->rx_sgl = NULL;
452 	mdata->tx_sgl_len = 0;
453 	mdata->rx_sgl_len = 0;
454 	mdata->cur_transfer = xfer;
455 	mdata->num_xfered = 0;
456 
457 	mtk_spi_prepare_transfer(master, xfer);
458 
459 	cmd = readl(mdata->base + SPI_CMD_REG);
460 	if (xfer->tx_buf)
461 		cmd |= SPI_CMD_TX_DMA;
462 	if (xfer->rx_buf)
463 		cmd |= SPI_CMD_RX_DMA;
464 	writel(cmd, mdata->base + SPI_CMD_REG);
465 
466 	if (xfer->tx_buf)
467 		mdata->tx_sgl = xfer->tx_sg.sgl;
468 	if (xfer->rx_buf)
469 		mdata->rx_sgl = xfer->rx_sg.sgl;
470 
471 	if (mdata->tx_sgl) {
472 		xfer->tx_dma = sg_dma_address(mdata->tx_sgl);
473 		mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
474 	}
475 	if (mdata->rx_sgl) {
476 		xfer->rx_dma = sg_dma_address(mdata->rx_sgl);
477 		mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
478 	}
479 
480 	mtk_spi_update_mdata_len(master);
481 	mtk_spi_setup_packet(master);
482 	mtk_spi_setup_dma_addr(master, xfer);
483 	mtk_spi_enable_transfer(master);
484 
485 	return 1;
486 }
487 
488 static int mtk_spi_transfer_one(struct spi_master *master,
489 				struct spi_device *spi,
490 				struct spi_transfer *xfer)
491 {
492 	if (master->can_dma(master, spi, xfer))
493 		return mtk_spi_dma_transfer(master, spi, xfer);
494 	else
495 		return mtk_spi_fifo_transfer(master, spi, xfer);
496 }
497 
498 static bool mtk_spi_can_dma(struct spi_master *master,
499 			    struct spi_device *spi,
500 			    struct spi_transfer *xfer)
501 {
502 	/* Buffers for DMA transactions must be 4-byte aligned */
503 	return (xfer->len > MTK_SPI_MAX_FIFO_SIZE &&
504 		(unsigned long)xfer->tx_buf % 4 == 0 &&
505 		(unsigned long)xfer->rx_buf % 4 == 0);
506 }
507 
508 static int mtk_spi_setup(struct spi_device *spi)
509 {
510 	struct mtk_spi *mdata = spi_master_get_devdata(spi->master);
511 
512 	if (!spi->controller_data)
513 		spi->controller_data = (void *)&mtk_default_chip_info;
514 
515 	if (mdata->dev_comp->need_pad_sel && gpio_is_valid(spi->cs_gpio))
516 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
517 
518 	return 0;
519 }
520 
521 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
522 {
523 	u32 cmd, reg_val, cnt, remainder, len;
524 	struct spi_master *master = dev_id;
525 	struct mtk_spi *mdata = spi_master_get_devdata(master);
526 	struct spi_transfer *trans = mdata->cur_transfer;
527 
528 	reg_val = readl(mdata->base + SPI_STATUS0_REG);
529 	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
530 		mdata->state = MTK_SPI_PAUSED;
531 	else
532 		mdata->state = MTK_SPI_IDLE;
533 
534 	if (!master->can_dma(master, master->cur_msg->spi, trans)) {
535 		if (trans->rx_buf) {
536 			cnt = mdata->xfer_len / 4;
537 			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
538 				     trans->rx_buf + mdata->num_xfered, cnt);
539 			remainder = mdata->xfer_len % 4;
540 			if (remainder > 0) {
541 				reg_val = readl(mdata->base + SPI_RX_DATA_REG);
542 				memcpy(trans->rx_buf +
543 					mdata->num_xfered +
544 					(cnt * 4),
545 					&reg_val,
546 					remainder);
547 			}
548 		}
549 
550 		mdata->num_xfered += mdata->xfer_len;
551 		if (mdata->num_xfered == trans->len) {
552 			spi_finalize_current_transfer(master);
553 			return IRQ_HANDLED;
554 		}
555 
556 		len = trans->len - mdata->num_xfered;
557 		mdata->xfer_len = min(MTK_SPI_MAX_FIFO_SIZE, len);
558 		mtk_spi_setup_packet(master);
559 
560 		cnt = mdata->xfer_len / 4;
561 		iowrite32_rep(mdata->base + SPI_TX_DATA_REG,
562 				trans->tx_buf + mdata->num_xfered, cnt);
563 
564 		remainder = mdata->xfer_len % 4;
565 		if (remainder > 0) {
566 			reg_val = 0;
567 			memcpy(&reg_val,
568 				trans->tx_buf + (cnt * 4) + mdata->num_xfered,
569 				remainder);
570 			writel(reg_val, mdata->base + SPI_TX_DATA_REG);
571 		}
572 
573 		mtk_spi_enable_transfer(master);
574 
575 		return IRQ_HANDLED;
576 	}
577 
578 	if (mdata->tx_sgl)
579 		trans->tx_dma += mdata->xfer_len;
580 	if (mdata->rx_sgl)
581 		trans->rx_dma += mdata->xfer_len;
582 
583 	if (mdata->tx_sgl && (mdata->tx_sgl_len == 0)) {
584 		mdata->tx_sgl = sg_next(mdata->tx_sgl);
585 		if (mdata->tx_sgl) {
586 			trans->tx_dma = sg_dma_address(mdata->tx_sgl);
587 			mdata->tx_sgl_len = sg_dma_len(mdata->tx_sgl);
588 		}
589 	}
590 	if (mdata->rx_sgl && (mdata->rx_sgl_len == 0)) {
591 		mdata->rx_sgl = sg_next(mdata->rx_sgl);
592 		if (mdata->rx_sgl) {
593 			trans->rx_dma = sg_dma_address(mdata->rx_sgl);
594 			mdata->rx_sgl_len = sg_dma_len(mdata->rx_sgl);
595 		}
596 	}
597 
598 	if (!mdata->tx_sgl && !mdata->rx_sgl) {
599 		/* spi disable dma */
600 		cmd = readl(mdata->base + SPI_CMD_REG);
601 		cmd &= ~SPI_CMD_TX_DMA;
602 		cmd &= ~SPI_CMD_RX_DMA;
603 		writel(cmd, mdata->base + SPI_CMD_REG);
604 
605 		spi_finalize_current_transfer(master);
606 		return IRQ_HANDLED;
607 	}
608 
609 	mtk_spi_update_mdata_len(master);
610 	mtk_spi_setup_packet(master);
611 	mtk_spi_setup_dma_addr(master, trans);
612 	mtk_spi_enable_transfer(master);
613 
614 	return IRQ_HANDLED;
615 }
616 
617 static int mtk_spi_probe(struct platform_device *pdev)
618 {
619 	struct spi_master *master;
620 	struct mtk_spi *mdata;
621 	const struct of_device_id *of_id;
622 	struct resource *res;
623 	int i, irq, ret, addr_bits;
624 
625 	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
626 	if (!master) {
627 		dev_err(&pdev->dev, "failed to alloc spi master\n");
628 		return -ENOMEM;
629 	}
630 
631 	master->auto_runtime_pm = true;
632 	master->dev.of_node = pdev->dev.of_node;
633 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
634 
635 	master->set_cs = mtk_spi_set_cs;
636 	master->prepare_message = mtk_spi_prepare_message;
637 	master->transfer_one = mtk_spi_transfer_one;
638 	master->can_dma = mtk_spi_can_dma;
639 	master->setup = mtk_spi_setup;
640 
641 	of_id = of_match_node(mtk_spi_of_match, pdev->dev.of_node);
642 	if (!of_id) {
643 		dev_err(&pdev->dev, "failed to probe of_node\n");
644 		ret = -EINVAL;
645 		goto err_put_master;
646 	}
647 
648 	mdata = spi_master_get_devdata(master);
649 	mdata->dev_comp = of_id->data;
650 	if (mdata->dev_comp->must_tx)
651 		master->flags = SPI_MASTER_MUST_TX;
652 
653 	if (mdata->dev_comp->need_pad_sel) {
654 		mdata->pad_num = of_property_count_u32_elems(
655 			pdev->dev.of_node,
656 			"mediatek,pad-select");
657 		if (mdata->pad_num < 0) {
658 			dev_err(&pdev->dev,
659 				"No 'mediatek,pad-select' property\n");
660 			ret = -EINVAL;
661 			goto err_put_master;
662 		}
663 
664 		mdata->pad_sel = devm_kmalloc_array(&pdev->dev, mdata->pad_num,
665 						    sizeof(u32), GFP_KERNEL);
666 		if (!mdata->pad_sel) {
667 			ret = -ENOMEM;
668 			goto err_put_master;
669 		}
670 
671 		for (i = 0; i < mdata->pad_num; i++) {
672 			of_property_read_u32_index(pdev->dev.of_node,
673 						   "mediatek,pad-select",
674 						   i, &mdata->pad_sel[i]);
675 			if (mdata->pad_sel[i] > MT8173_SPI_MAX_PAD_SEL) {
676 				dev_err(&pdev->dev, "wrong pad-sel[%d]: %u\n",
677 					i, mdata->pad_sel[i]);
678 				ret = -EINVAL;
679 				goto err_put_master;
680 			}
681 		}
682 	}
683 
684 	platform_set_drvdata(pdev, master);
685 
686 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
687 	if (!res) {
688 		ret = -ENODEV;
689 		dev_err(&pdev->dev, "failed to determine base address\n");
690 		goto err_put_master;
691 	}
692 
693 	mdata->base = devm_ioremap_resource(&pdev->dev, res);
694 	if (IS_ERR(mdata->base)) {
695 		ret = PTR_ERR(mdata->base);
696 		goto err_put_master;
697 	}
698 
699 	irq = platform_get_irq(pdev, 0);
700 	if (irq < 0) {
701 		ret = irq;
702 		goto err_put_master;
703 	}
704 
705 	if (!pdev->dev.dma_mask)
706 		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
707 
708 	ret = devm_request_irq(&pdev->dev, irq, mtk_spi_interrupt,
709 			       IRQF_TRIGGER_NONE, dev_name(&pdev->dev), master);
710 	if (ret) {
711 		dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
712 		goto err_put_master;
713 	}
714 
715 	mdata->parent_clk = devm_clk_get(&pdev->dev, "parent-clk");
716 	if (IS_ERR(mdata->parent_clk)) {
717 		ret = PTR_ERR(mdata->parent_clk);
718 		dev_err(&pdev->dev, "failed to get parent-clk: %d\n", ret);
719 		goto err_put_master;
720 	}
721 
722 	mdata->sel_clk = devm_clk_get(&pdev->dev, "sel-clk");
723 	if (IS_ERR(mdata->sel_clk)) {
724 		ret = PTR_ERR(mdata->sel_clk);
725 		dev_err(&pdev->dev, "failed to get sel-clk: %d\n", ret);
726 		goto err_put_master;
727 	}
728 
729 	mdata->spi_clk = devm_clk_get(&pdev->dev, "spi-clk");
730 	if (IS_ERR(mdata->spi_clk)) {
731 		ret = PTR_ERR(mdata->spi_clk);
732 		dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
733 		goto err_put_master;
734 	}
735 
736 	ret = clk_prepare_enable(mdata->spi_clk);
737 	if (ret < 0) {
738 		dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
739 		goto err_put_master;
740 	}
741 
742 	ret = clk_set_parent(mdata->sel_clk, mdata->parent_clk);
743 	if (ret < 0) {
744 		dev_err(&pdev->dev, "failed to clk_set_parent (%d)\n", ret);
745 		clk_disable_unprepare(mdata->spi_clk);
746 		goto err_put_master;
747 	}
748 
749 	clk_disable_unprepare(mdata->spi_clk);
750 
751 	pm_runtime_enable(&pdev->dev);
752 
753 	ret = devm_spi_register_master(&pdev->dev, master);
754 	if (ret) {
755 		dev_err(&pdev->dev, "failed to register master (%d)\n", ret);
756 		goto err_disable_runtime_pm;
757 	}
758 
759 	if (mdata->dev_comp->need_pad_sel) {
760 		if (mdata->pad_num != master->num_chipselect) {
761 			dev_err(&pdev->dev,
762 				"pad_num does not match num_chipselect(%d != %d)\n",
763 				mdata->pad_num, master->num_chipselect);
764 			ret = -EINVAL;
765 			goto err_disable_runtime_pm;
766 		}
767 
768 		if (!master->cs_gpios && master->num_chipselect > 1) {
769 			dev_err(&pdev->dev,
770 				"cs_gpios not specified and num_chipselect > 1\n");
771 			ret = -EINVAL;
772 			goto err_disable_runtime_pm;
773 		}
774 
775 		if (master->cs_gpios) {
776 			for (i = 0; i < master->num_chipselect; i++) {
777 				ret = devm_gpio_request(&pdev->dev,
778 							master->cs_gpios[i],
779 							dev_name(&pdev->dev));
780 				if (ret) {
781 					dev_err(&pdev->dev,
782 						"can't get CS GPIO %i\n", i);
783 					goto err_disable_runtime_pm;
784 				}
785 			}
786 		}
787 	}
788 
789 	if (mdata->dev_comp->dma_ext)
790 		addr_bits = DMA_ADDR_EXT_BITS;
791 	else
792 		addr_bits = DMA_ADDR_DEF_BITS;
793 	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(addr_bits));
794 	if (ret)
795 		dev_notice(&pdev->dev, "SPI dma_set_mask(%d) failed, ret:%d\n",
796 			   addr_bits, ret);
797 
798 	return 0;
799 
800 err_disable_runtime_pm:
801 	pm_runtime_disable(&pdev->dev);
802 err_put_master:
803 	spi_master_put(master);
804 
805 	return ret;
806 }
807 
808 static int mtk_spi_remove(struct platform_device *pdev)
809 {
810 	struct spi_master *master = platform_get_drvdata(pdev);
811 	struct mtk_spi *mdata = spi_master_get_devdata(master);
812 
813 	pm_runtime_disable(&pdev->dev);
814 
815 	mtk_spi_reset(mdata);
816 
817 	return 0;
818 }
819 
820 #ifdef CONFIG_PM_SLEEP
821 static int mtk_spi_suspend(struct device *dev)
822 {
823 	int ret;
824 	struct spi_master *master = dev_get_drvdata(dev);
825 	struct mtk_spi *mdata = spi_master_get_devdata(master);
826 
827 	ret = spi_master_suspend(master);
828 	if (ret)
829 		return ret;
830 
831 	if (!pm_runtime_suspended(dev))
832 		clk_disable_unprepare(mdata->spi_clk);
833 
834 	return ret;
835 }
836 
837 static int mtk_spi_resume(struct device *dev)
838 {
839 	int ret;
840 	struct spi_master *master = dev_get_drvdata(dev);
841 	struct mtk_spi *mdata = spi_master_get_devdata(master);
842 
843 	if (!pm_runtime_suspended(dev)) {
844 		ret = clk_prepare_enable(mdata->spi_clk);
845 		if (ret < 0) {
846 			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
847 			return ret;
848 		}
849 	}
850 
851 	ret = spi_master_resume(master);
852 	if (ret < 0)
853 		clk_disable_unprepare(mdata->spi_clk);
854 
855 	return ret;
856 }
857 #endif /* CONFIG_PM_SLEEP */
858 
859 #ifdef CONFIG_PM
860 static int mtk_spi_runtime_suspend(struct device *dev)
861 {
862 	struct spi_master *master = dev_get_drvdata(dev);
863 	struct mtk_spi *mdata = spi_master_get_devdata(master);
864 
865 	clk_disable_unprepare(mdata->spi_clk);
866 
867 	return 0;
868 }
869 
870 static int mtk_spi_runtime_resume(struct device *dev)
871 {
872 	struct spi_master *master = dev_get_drvdata(dev);
873 	struct mtk_spi *mdata = spi_master_get_devdata(master);
874 	int ret;
875 
876 	ret = clk_prepare_enable(mdata->spi_clk);
877 	if (ret < 0) {
878 		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
879 		return ret;
880 	}
881 
882 	return 0;
883 }
884 #endif /* CONFIG_PM */
885 
886 static const struct dev_pm_ops mtk_spi_pm = {
887 	SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_suspend, mtk_spi_resume)
888 	SET_RUNTIME_PM_OPS(mtk_spi_runtime_suspend,
889 			   mtk_spi_runtime_resume, NULL)
890 };
891 
892 static struct platform_driver mtk_spi_driver = {
893 	.driver = {
894 		.name = "mtk-spi",
895 		.pm	= &mtk_spi_pm,
896 		.of_match_table = mtk_spi_of_match,
897 	},
898 	.probe = mtk_spi_probe,
899 	.remove = mtk_spi_remove,
900 };
901 
902 module_platform_driver(mtk_spi_driver);
903 
904 MODULE_DESCRIPTION("MTK SPI Controller driver");
905 MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
906 MODULE_LICENSE("GPL v2");
907 MODULE_ALIAS("platform:mtk-spi");
908