1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Rockchip Serial Flash Controller Driver
4  *
5  * Copyright (c) 2017-2021, Rockchip Inc.
6  * Author: Shawn Lin <shawn.lin@rock-chips.com>
7  *	   Chris Morgan <macroalpha82@gmail.com>
8  *	   Jon Lin <Jon.lin@rock-chips.com>
9  */
10 
11 #include <linux/bitops.h>
12 #include <linux/clk.h>
13 #include <linux/completion.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/iopoll.h>
16 #include <linux/mm.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 #include <linux/interrupt.h>
22 #include <linux/spi/spi-mem.h>
23 
24 /* System control */
25 #define SFC_CTRL			0x0
26 #define  SFC_CTRL_PHASE_SEL_NEGETIVE	BIT(1)
27 #define  SFC_CTRL_CMD_BITS_SHIFT	8
28 #define  SFC_CTRL_ADDR_BITS_SHIFT	10
29 #define  SFC_CTRL_DATA_BITS_SHIFT	12
30 
31 /* Interrupt mask */
32 #define SFC_IMR				0x4
33 #define  SFC_IMR_RX_FULL		BIT(0)
34 #define  SFC_IMR_RX_UFLOW		BIT(1)
35 #define  SFC_IMR_TX_OFLOW		BIT(2)
36 #define  SFC_IMR_TX_EMPTY		BIT(3)
37 #define  SFC_IMR_TRAN_FINISH		BIT(4)
38 #define  SFC_IMR_BUS_ERR		BIT(5)
39 #define  SFC_IMR_NSPI_ERR		BIT(6)
40 #define  SFC_IMR_DMA			BIT(7)
41 
42 /* Interrupt clear */
43 #define SFC_ICLR			0x8
44 #define  SFC_ICLR_RX_FULL		BIT(0)
45 #define  SFC_ICLR_RX_UFLOW		BIT(1)
46 #define  SFC_ICLR_TX_OFLOW		BIT(2)
47 #define  SFC_ICLR_TX_EMPTY		BIT(3)
48 #define  SFC_ICLR_TRAN_FINISH		BIT(4)
49 #define  SFC_ICLR_BUS_ERR		BIT(5)
50 #define  SFC_ICLR_NSPI_ERR		BIT(6)
51 #define  SFC_ICLR_DMA			BIT(7)
52 
53 /* FIFO threshold level */
54 #define SFC_FTLR			0xc
55 #define  SFC_FTLR_TX_SHIFT		0
56 #define  SFC_FTLR_TX_MASK		0x1f
57 #define  SFC_FTLR_RX_SHIFT		8
58 #define  SFC_FTLR_RX_MASK		0x1f
59 
60 /* Reset FSM and FIFO */
61 #define SFC_RCVR			0x10
62 #define  SFC_RCVR_RESET			BIT(0)
63 
64 /* Enhanced mode */
65 #define SFC_AX				0x14
66 
67 /* Address Bit number */
68 #define SFC_ABIT			0x18
69 
70 /* Interrupt status */
71 #define SFC_ISR				0x1c
72 #define  SFC_ISR_RX_FULL_SHIFT		BIT(0)
73 #define  SFC_ISR_RX_UFLOW_SHIFT		BIT(1)
74 #define  SFC_ISR_TX_OFLOW_SHIFT		BIT(2)
75 #define  SFC_ISR_TX_EMPTY_SHIFT		BIT(3)
76 #define  SFC_ISR_TX_FINISH_SHIFT	BIT(4)
77 #define  SFC_ISR_BUS_ERR_SHIFT		BIT(5)
78 #define  SFC_ISR_NSPI_ERR_SHIFT		BIT(6)
79 #define  SFC_ISR_DMA_SHIFT		BIT(7)
80 
81 /* FIFO status */
82 #define SFC_FSR				0x20
83 #define  SFC_FSR_TX_IS_FULL		BIT(0)
84 #define  SFC_FSR_TX_IS_EMPTY		BIT(1)
85 #define  SFC_FSR_RX_IS_EMPTY		BIT(2)
86 #define  SFC_FSR_RX_IS_FULL		BIT(3)
87 #define  SFC_FSR_TXLV_MASK		GENMASK(12, 8)
88 #define  SFC_FSR_TXLV_SHIFT		8
89 #define  SFC_FSR_RXLV_MASK		GENMASK(20, 16)
90 #define  SFC_FSR_RXLV_SHIFT		16
91 
92 /* FSM status */
93 #define SFC_SR				0x24
94 #define  SFC_SR_IS_IDLE			0x0
95 #define  SFC_SR_IS_BUSY			0x1
96 
97 /* Raw interrupt status */
98 #define SFC_RISR			0x28
99 #define  SFC_RISR_RX_FULL		BIT(0)
100 #define  SFC_RISR_RX_UNDERFLOW		BIT(1)
101 #define  SFC_RISR_TX_OVERFLOW		BIT(2)
102 #define  SFC_RISR_TX_EMPTY		BIT(3)
103 #define  SFC_RISR_TRAN_FINISH		BIT(4)
104 #define  SFC_RISR_BUS_ERR		BIT(5)
105 #define  SFC_RISR_NSPI_ERR		BIT(6)
106 #define  SFC_RISR_DMA			BIT(7)
107 
108 /* Version */
109 #define SFC_VER				0x2C
110 #define  SFC_VER_3			0x3
111 #define  SFC_VER_4			0x4
112 #define  SFC_VER_5			0x5
113 
114 /* Delay line controller resiter */
115 #define SFC_DLL_CTRL0			0x3C
116 #define SFC_DLL_CTRL0_SCLK_SMP_DLL	BIT(15)
117 #define SFC_DLL_CTRL0_DLL_MAX_VER4	0xFFU
118 #define SFC_DLL_CTRL0_DLL_MAX_VER5	0x1FFU
119 
120 /* Master trigger */
121 #define SFC_DMA_TRIGGER			0x80
122 #define SFC_DMA_TRIGGER_START		1
123 
124 /* Src or Dst addr for master */
125 #define SFC_DMA_ADDR			0x84
126 
127 /* Length control register extension 32GB */
128 #define SFC_LEN_CTRL			0x88
129 #define SFC_LEN_CTRL_TRB_SEL		1
130 #define SFC_LEN_EXT			0x8C
131 
132 /* Command */
133 #define SFC_CMD				0x100
134 #define  SFC_CMD_IDX_SHIFT		0
135 #define  SFC_CMD_DUMMY_SHIFT		8
136 #define  SFC_CMD_DIR_SHIFT		12
137 #define  SFC_CMD_DIR_RD			0
138 #define  SFC_CMD_DIR_WR			1
139 #define  SFC_CMD_ADDR_SHIFT		14
140 #define  SFC_CMD_ADDR_0BITS		0
141 #define  SFC_CMD_ADDR_24BITS		1
142 #define  SFC_CMD_ADDR_32BITS		2
143 #define  SFC_CMD_ADDR_XBITS		3
144 #define  SFC_CMD_TRAN_BYTES_SHIFT	16
145 #define  SFC_CMD_CS_SHIFT		30
146 
147 /* Address */
148 #define SFC_ADDR			0x104
149 
150 /* Data */
151 #define SFC_DATA			0x108
152 
153 /* The controller and documentation reports that it supports up to 4 CS
154  * devices (0-3), however I have only been able to test a single CS (CS 0)
155  * due to the configuration of my device.
156  */
157 #define SFC_MAX_CHIPSELECT_NUM		4
158 
159 /* The SFC can transfer max 16KB - 1 at one time
160  * we set it to 15.5KB here for alignment.
161  */
162 #define SFC_MAX_IOSIZE_VER3		(512 * 31)
163 
164 /* DMA is only enabled for large data transmission */
165 #define SFC_DMA_TRANS_THRETHOLD		(0x40)
166 
167 /* Maximum clock values from datasheet suggest keeping clock value under
168  * 150MHz. No minimum or average value is suggested.
169  */
170 #define SFC_MAX_SPEED		(150 * 1000 * 1000)
171 
172 struct rockchip_sfc {
173 	struct device *dev;
174 	void __iomem *regbase;
175 	struct clk *hclk;
176 	struct clk *clk;
177 	u32 frequency;
178 	/* virtual mapped addr for dma_buffer */
179 	void *buffer;
180 	dma_addr_t dma_buffer;
181 	struct completion cp;
182 	bool use_dma;
183 	u32 max_iosize;
184 	u16 version;
185 };
186 
187 static int rockchip_sfc_reset(struct rockchip_sfc *sfc)
188 {
189 	int err;
190 	u32 status;
191 
192 	writel_relaxed(SFC_RCVR_RESET, sfc->regbase + SFC_RCVR);
193 
194 	err = readl_poll_timeout(sfc->regbase + SFC_RCVR, status,
195 				 !(status & SFC_RCVR_RESET), 20,
196 				 jiffies_to_usecs(HZ));
197 	if (err)
198 		dev_err(sfc->dev, "SFC reset never finished\n");
199 
200 	/* Still need to clear the masked interrupt from RISR */
201 	writel_relaxed(0xFFFFFFFF, sfc->regbase + SFC_ICLR);
202 
203 	dev_dbg(sfc->dev, "reset\n");
204 
205 	return err;
206 }
207 
208 static u16 rockchip_sfc_get_version(struct rockchip_sfc *sfc)
209 {
210 	return  (u16)(readl(sfc->regbase + SFC_VER) & 0xffff);
211 }
212 
213 static u32 rockchip_sfc_get_max_iosize(struct rockchip_sfc *sfc)
214 {
215 	return SFC_MAX_IOSIZE_VER3;
216 }
217 
218 static void rockchip_sfc_irq_unmask(struct rockchip_sfc *sfc, u32 mask)
219 {
220 	u32 reg;
221 
222 	/* Enable transfer complete interrupt */
223 	reg = readl(sfc->regbase + SFC_IMR);
224 	reg &= ~mask;
225 	writel(reg, sfc->regbase + SFC_IMR);
226 }
227 
228 static void rockchip_sfc_irq_mask(struct rockchip_sfc *sfc, u32 mask)
229 {
230 	u32 reg;
231 
232 	/* Disable transfer finish interrupt */
233 	reg = readl(sfc->regbase + SFC_IMR);
234 	reg |= mask;
235 	writel(reg, sfc->regbase + SFC_IMR);
236 }
237 
238 static int rockchip_sfc_init(struct rockchip_sfc *sfc)
239 {
240 	writel(0, sfc->regbase + SFC_CTRL);
241 	writel(0xFFFFFFFF, sfc->regbase + SFC_ICLR);
242 	rockchip_sfc_irq_mask(sfc, 0xFFFFFFFF);
243 	if (rockchip_sfc_get_version(sfc) >= SFC_VER_4)
244 		writel(SFC_LEN_CTRL_TRB_SEL, sfc->regbase + SFC_LEN_CTRL);
245 
246 	return 0;
247 }
248 
249 static int rockchip_sfc_wait_txfifo_ready(struct rockchip_sfc *sfc, u32 timeout_us)
250 {
251 	int ret = 0;
252 	u32 status;
253 
254 	ret = readl_poll_timeout(sfc->regbase + SFC_FSR, status,
255 				 status & SFC_FSR_TXLV_MASK, 0,
256 				 timeout_us);
257 	if (ret) {
258 		dev_dbg(sfc->dev, "sfc wait tx fifo timeout\n");
259 
260 		return -ETIMEDOUT;
261 	}
262 
263 	return (status & SFC_FSR_TXLV_MASK) >> SFC_FSR_TXLV_SHIFT;
264 }
265 
266 static int rockchip_sfc_wait_rxfifo_ready(struct rockchip_sfc *sfc, u32 timeout_us)
267 {
268 	int ret = 0;
269 	u32 status;
270 
271 	ret = readl_poll_timeout(sfc->regbase + SFC_FSR, status,
272 				 status & SFC_FSR_RXLV_MASK, 0,
273 				 timeout_us);
274 	if (ret) {
275 		dev_dbg(sfc->dev, "sfc wait rx fifo timeout\n");
276 
277 		return -ETIMEDOUT;
278 	}
279 
280 	return (status & SFC_FSR_RXLV_MASK) >> SFC_FSR_RXLV_SHIFT;
281 }
282 
283 static void rockchip_sfc_adjust_op_work(struct spi_mem_op *op)
284 {
285 	if (unlikely(op->dummy.nbytes && !op->addr.nbytes)) {
286 		/*
287 		 * SFC not support output DUMMY cycles right after CMD cycles, so
288 		 * treat it as ADDR cycles.
289 		 */
290 		op->addr.nbytes = op->dummy.nbytes;
291 		op->addr.buswidth = op->dummy.buswidth;
292 		op->addr.val = 0xFFFFFFFFF;
293 
294 		op->dummy.nbytes = 0;
295 	}
296 }
297 
298 static int rockchip_sfc_xfer_setup(struct rockchip_sfc *sfc,
299 				   struct spi_mem *mem,
300 				   const struct spi_mem_op *op,
301 				   u32 len)
302 {
303 	u32 ctrl = 0, cmd = 0;
304 
305 	/* set CMD */
306 	cmd = op->cmd.opcode;
307 	ctrl |= ((op->cmd.buswidth >> 1) << SFC_CTRL_CMD_BITS_SHIFT);
308 
309 	/* set ADDR */
310 	if (op->addr.nbytes) {
311 		if (op->addr.nbytes == 4) {
312 			cmd |= SFC_CMD_ADDR_32BITS << SFC_CMD_ADDR_SHIFT;
313 		} else if (op->addr.nbytes == 3) {
314 			cmd |= SFC_CMD_ADDR_24BITS << SFC_CMD_ADDR_SHIFT;
315 		} else {
316 			cmd |= SFC_CMD_ADDR_XBITS << SFC_CMD_ADDR_SHIFT;
317 			writel(op->addr.nbytes * 8 - 1, sfc->regbase + SFC_ABIT);
318 		}
319 
320 		ctrl |= ((op->addr.buswidth >> 1) << SFC_CTRL_ADDR_BITS_SHIFT);
321 	}
322 
323 	/* set DUMMY */
324 	if (op->dummy.nbytes) {
325 		if (op->dummy.buswidth == 4)
326 			cmd |= op->dummy.nbytes * 2 << SFC_CMD_DUMMY_SHIFT;
327 		else if (op->dummy.buswidth == 2)
328 			cmd |= op->dummy.nbytes * 4 << SFC_CMD_DUMMY_SHIFT;
329 		else
330 			cmd |= op->dummy.nbytes * 8 << SFC_CMD_DUMMY_SHIFT;
331 	}
332 
333 	/* set DATA */
334 	if (sfc->version >= SFC_VER_4) /* Clear it if no data to transfer */
335 		writel(len, sfc->regbase + SFC_LEN_EXT);
336 	else
337 		cmd |= len << SFC_CMD_TRAN_BYTES_SHIFT;
338 	if (len) {
339 		if (op->data.dir == SPI_MEM_DATA_OUT)
340 			cmd |= SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT;
341 
342 		ctrl |= ((op->data.buswidth >> 1) << SFC_CTRL_DATA_BITS_SHIFT);
343 	}
344 	if (!len && op->addr.nbytes)
345 		cmd |= SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT;
346 
347 	/* set the Controller */
348 	ctrl |= SFC_CTRL_PHASE_SEL_NEGETIVE;
349 	cmd |= mem->spi->chip_select << SFC_CMD_CS_SHIFT;
350 
351 	dev_dbg(sfc->dev, "sfc addr.nbytes=%x(x%d) dummy.nbytes=%x(x%d)\n",
352 		op->addr.nbytes, op->addr.buswidth,
353 		op->dummy.nbytes, op->dummy.buswidth);
354 	dev_dbg(sfc->dev, "sfc ctrl=%x cmd=%x addr=%llx len=%x\n",
355 		ctrl, cmd, op->addr.val, len);
356 
357 	writel(ctrl, sfc->regbase + SFC_CTRL);
358 	writel(cmd, sfc->regbase + SFC_CMD);
359 	if (op->addr.nbytes)
360 		writel(op->addr.val, sfc->regbase + SFC_ADDR);
361 
362 	return 0;
363 }
364 
365 static int rockchip_sfc_write_fifo(struct rockchip_sfc *sfc, const u8 *buf, int len)
366 {
367 	u8 bytes = len & 0x3;
368 	u32 dwords;
369 	int tx_level;
370 	u32 write_words;
371 	u32 tmp = 0;
372 
373 	dwords = len >> 2;
374 	while (dwords) {
375 		tx_level = rockchip_sfc_wait_txfifo_ready(sfc, 1000);
376 		if (tx_level < 0)
377 			return tx_level;
378 		write_words = min_t(u32, tx_level, dwords);
379 		iowrite32_rep(sfc->regbase + SFC_DATA, buf, write_words);
380 		buf += write_words << 2;
381 		dwords -= write_words;
382 	}
383 
384 	/* write the rest non word aligned bytes */
385 	if (bytes) {
386 		tx_level = rockchip_sfc_wait_txfifo_ready(sfc, 1000);
387 		if (tx_level < 0)
388 			return tx_level;
389 		memcpy(&tmp, buf, bytes);
390 		writel(tmp, sfc->regbase + SFC_DATA);
391 	}
392 
393 	return len;
394 }
395 
396 static int rockchip_sfc_read_fifo(struct rockchip_sfc *sfc, u8 *buf, int len)
397 {
398 	u8 bytes = len & 0x3;
399 	u32 dwords;
400 	u8 read_words;
401 	int rx_level;
402 	int tmp;
403 
404 	/* word aligned access only */
405 	dwords = len >> 2;
406 	while (dwords) {
407 		rx_level = rockchip_sfc_wait_rxfifo_ready(sfc, 1000);
408 		if (rx_level < 0)
409 			return rx_level;
410 		read_words = min_t(u32, rx_level, dwords);
411 		ioread32_rep(sfc->regbase + SFC_DATA, buf, read_words);
412 		buf += read_words << 2;
413 		dwords -= read_words;
414 	}
415 
416 	/* read the rest non word aligned bytes */
417 	if (bytes) {
418 		rx_level = rockchip_sfc_wait_rxfifo_ready(sfc, 1000);
419 		if (rx_level < 0)
420 			return rx_level;
421 		tmp = readl(sfc->regbase + SFC_DATA);
422 		memcpy(buf, &tmp, bytes);
423 	}
424 
425 	return len;
426 }
427 
428 static int rockchip_sfc_fifo_transfer_dma(struct rockchip_sfc *sfc, dma_addr_t dma_buf, size_t len)
429 {
430 	writel(0xFFFFFFFF, sfc->regbase + SFC_ICLR);
431 	writel((u32)dma_buf, sfc->regbase + SFC_DMA_ADDR);
432 	writel(SFC_DMA_TRIGGER_START, sfc->regbase + SFC_DMA_TRIGGER);
433 
434 	return len;
435 }
436 
437 static int rockchip_sfc_xfer_data_poll(struct rockchip_sfc *sfc,
438 				       const struct spi_mem_op *op, u32 len)
439 {
440 	dev_dbg(sfc->dev, "sfc xfer_poll len=%x\n", len);
441 
442 	if (op->data.dir == SPI_MEM_DATA_OUT)
443 		return rockchip_sfc_write_fifo(sfc, op->data.buf.out, len);
444 	else
445 		return rockchip_sfc_read_fifo(sfc, op->data.buf.in, len);
446 }
447 
448 static int rockchip_sfc_xfer_data_dma(struct rockchip_sfc *sfc,
449 				      const struct spi_mem_op *op, u32 len)
450 {
451 	int ret;
452 
453 	dev_dbg(sfc->dev, "sfc xfer_dma len=%x\n", len);
454 
455 	if (op->data.dir == SPI_MEM_DATA_OUT)
456 		memcpy(sfc->buffer, op->data.buf.out, len);
457 
458 	ret = rockchip_sfc_fifo_transfer_dma(sfc, sfc->dma_buffer, len);
459 	if (!wait_for_completion_timeout(&sfc->cp, msecs_to_jiffies(2000))) {
460 		dev_err(sfc->dev, "DMA wait for transfer finish timeout\n");
461 		ret = -ETIMEDOUT;
462 	}
463 	rockchip_sfc_irq_mask(sfc, SFC_IMR_DMA);
464 	if (op->data.dir == SPI_MEM_DATA_IN)
465 		memcpy(op->data.buf.in, sfc->buffer, len);
466 
467 	return ret;
468 }
469 
470 static int rockchip_sfc_xfer_done(struct rockchip_sfc *sfc, u32 timeout_us)
471 {
472 	int ret = 0;
473 	u32 status;
474 
475 	ret = readl_poll_timeout(sfc->regbase + SFC_SR, status,
476 				 !(status & SFC_SR_IS_BUSY),
477 				 20, timeout_us);
478 	if (ret) {
479 		dev_err(sfc->dev, "wait sfc idle timeout\n");
480 		rockchip_sfc_reset(sfc);
481 
482 		ret = -EIO;
483 	}
484 
485 	return ret;
486 }
487 
488 static int rockchip_sfc_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
489 {
490 	struct rockchip_sfc *sfc = spi_master_get_devdata(mem->spi->master);
491 	u32 len = op->data.nbytes;
492 	int ret;
493 
494 	if (unlikely(mem->spi->max_speed_hz != sfc->frequency)) {
495 		ret = clk_set_rate(sfc->clk, mem->spi->max_speed_hz);
496 		if (ret)
497 			return ret;
498 		sfc->frequency = mem->spi->max_speed_hz;
499 		dev_dbg(sfc->dev, "set_freq=%dHz real_freq=%ldHz\n",
500 			sfc->frequency, clk_get_rate(sfc->clk));
501 	}
502 
503 	rockchip_sfc_adjust_op_work((struct spi_mem_op *)op);
504 	rockchip_sfc_xfer_setup(sfc, mem, op, len);
505 	if (len) {
506 		if (likely(sfc->use_dma) && len >= SFC_DMA_TRANS_THRETHOLD) {
507 			init_completion(&sfc->cp);
508 			rockchip_sfc_irq_unmask(sfc, SFC_IMR_DMA);
509 			ret = rockchip_sfc_xfer_data_dma(sfc, op, len);
510 		} else {
511 			ret = rockchip_sfc_xfer_data_poll(sfc, op, len);
512 		}
513 
514 		if (ret != len) {
515 			dev_err(sfc->dev, "xfer data failed ret %d dir %d\n", ret, op->data.dir);
516 
517 			return -EIO;
518 		}
519 	}
520 
521 	return rockchip_sfc_xfer_done(sfc, 100000);
522 }
523 
524 static int rockchip_sfc_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
525 {
526 	struct rockchip_sfc *sfc = spi_master_get_devdata(mem->spi->master);
527 
528 	op->data.nbytes = min(op->data.nbytes, sfc->max_iosize);
529 
530 	return 0;
531 }
532 
533 static const struct spi_controller_mem_ops rockchip_sfc_mem_ops = {
534 	.exec_op = rockchip_sfc_exec_mem_op,
535 	.adjust_op_size = rockchip_sfc_adjust_op_size,
536 };
537 
538 static irqreturn_t rockchip_sfc_irq_handler(int irq, void *dev_id)
539 {
540 	struct rockchip_sfc *sfc = dev_id;
541 	u32 reg;
542 
543 	reg = readl(sfc->regbase + SFC_RISR);
544 
545 	/* Clear interrupt */
546 	writel_relaxed(reg, sfc->regbase + SFC_ICLR);
547 
548 	if (reg & SFC_RISR_DMA) {
549 		complete(&sfc->cp);
550 
551 		return IRQ_HANDLED;
552 	}
553 
554 	return IRQ_NONE;
555 }
556 
557 static int rockchip_sfc_probe(struct platform_device *pdev)
558 {
559 	struct device *dev = &pdev->dev;
560 	struct spi_master *master;
561 	struct resource *res;
562 	struct rockchip_sfc *sfc;
563 	int ret;
564 
565 	master = devm_spi_alloc_master(&pdev->dev, sizeof(*sfc));
566 	if (!master)
567 		return -ENOMEM;
568 
569 	master->flags = SPI_MASTER_HALF_DUPLEX;
570 	master->mem_ops = &rockchip_sfc_mem_ops;
571 	master->dev.of_node = pdev->dev.of_node;
572 	master->mode_bits = SPI_TX_QUAD | SPI_TX_DUAL | SPI_RX_QUAD | SPI_RX_DUAL;
573 	master->max_speed_hz = SFC_MAX_SPEED;
574 	master->num_chipselect = SFC_MAX_CHIPSELECT_NUM;
575 
576 	sfc = spi_master_get_devdata(master);
577 	sfc->dev = dev;
578 
579 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
580 	sfc->regbase = devm_ioremap_resource(dev, res);
581 	if (IS_ERR(sfc->regbase))
582 		return PTR_ERR(sfc->regbase);
583 
584 	sfc->clk = devm_clk_get(&pdev->dev, "clk_sfc");
585 	if (IS_ERR(sfc->clk)) {
586 		dev_err(&pdev->dev, "Failed to get sfc interface clk\n");
587 		return PTR_ERR(sfc->clk);
588 	}
589 
590 	sfc->hclk = devm_clk_get(&pdev->dev, "hclk_sfc");
591 	if (IS_ERR(sfc->hclk)) {
592 		dev_err(&pdev->dev, "Failed to get sfc ahb clk\n");
593 		return PTR_ERR(sfc->hclk);
594 	}
595 
596 	sfc->use_dma = !of_property_read_bool(sfc->dev->of_node,
597 					      "rockchip,sfc-no-dma");
598 
599 	if (sfc->use_dma) {
600 		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
601 		if (ret) {
602 			dev_warn(dev, "Unable to set dma mask\n");
603 			return ret;
604 		}
605 
606 		sfc->buffer = dmam_alloc_coherent(dev, SFC_MAX_IOSIZE_VER3,
607 						  &sfc->dma_buffer,
608 						  GFP_KERNEL);
609 		if (!sfc->buffer)
610 			return -ENOMEM;
611 	}
612 
613 	ret = clk_prepare_enable(sfc->hclk);
614 	if (ret) {
615 		dev_err(&pdev->dev, "Failed to enable ahb clk\n");
616 		goto err_hclk;
617 	}
618 
619 	ret = clk_prepare_enable(sfc->clk);
620 	if (ret) {
621 		dev_err(&pdev->dev, "Failed to enable interface clk\n");
622 		goto err_clk;
623 	}
624 
625 	/* Find the irq */
626 	ret = platform_get_irq(pdev, 0);
627 	if (ret < 0)
628 		goto err_irq;
629 
630 	ret = devm_request_irq(dev, ret, rockchip_sfc_irq_handler,
631 			       0, pdev->name, sfc);
632 	if (ret) {
633 		dev_err(dev, "Failed to request irq\n");
634 
635 		goto err_irq;
636 	}
637 
638 	ret = rockchip_sfc_init(sfc);
639 	if (ret)
640 		goto err_irq;
641 
642 	sfc->max_iosize = rockchip_sfc_get_max_iosize(sfc);
643 	sfc->version = rockchip_sfc_get_version(sfc);
644 
645 	ret = spi_register_master(master);
646 	if (ret)
647 		goto err_irq;
648 
649 	return 0;
650 
651 err_irq:
652 	clk_disable_unprepare(sfc->clk);
653 err_clk:
654 	clk_disable_unprepare(sfc->hclk);
655 err_hclk:
656 	return ret;
657 }
658 
659 static int rockchip_sfc_remove(struct platform_device *pdev)
660 {
661 	struct spi_master *master = platform_get_drvdata(pdev);
662 	struct rockchip_sfc *sfc = platform_get_drvdata(pdev);
663 
664 	spi_unregister_master(master);
665 
666 	clk_disable_unprepare(sfc->clk);
667 	clk_disable_unprepare(sfc->hclk);
668 
669 	return 0;
670 }
671 
672 static const struct of_device_id rockchip_sfc_dt_ids[] = {
673 	{ .compatible = "rockchip,sfc"},
674 	{ /* sentinel */ }
675 };
676 MODULE_DEVICE_TABLE(of, rockchip_sfc_dt_ids);
677 
678 static struct platform_driver rockchip_sfc_driver = {
679 	.driver = {
680 		.name	= "rockchip-sfc",
681 		.of_match_table = rockchip_sfc_dt_ids,
682 	},
683 	.probe	= rockchip_sfc_probe,
684 	.remove	= rockchip_sfc_remove,
685 };
686 module_platform_driver(rockchip_sfc_driver);
687 
688 MODULE_LICENSE("GPL v2");
689 MODULE_DESCRIPTION("Rockchip Serial Flash Controller Driver");
690 MODULE_AUTHOR("Shawn Lin <shawn.lin@rock-chips.com>");
691 MODULE_AUTHOR("Chris Morgan <macromorgan@hotmail.com>");
692 MODULE_AUTHOR("Jon Lin <Jon.lin@rock-chips.com>");
693