xref: /openbmc/linux/drivers/spi/spi-mtk-nor.c (revision 3a35093a)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Mediatek SPI NOR controller driver
4 //
5 // Copyright (C) 2020 Chuanhong Guo <gch981213@gmail.com>
6 
7 #include <linux/bits.h>
8 #include <linux/clk.h>
9 #include <linux/completion.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/iopoll.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/spi/spi.h>
19 #include <linux/spi/spi-mem.h>
20 #include <linux/string.h>
21 
22 #define DRIVER_NAME "mtk-spi-nor"
23 
24 #define MTK_NOR_REG_CMD			0x00
25 #define MTK_NOR_CMD_WRITE		BIT(4)
26 #define MTK_NOR_CMD_PROGRAM		BIT(2)
27 #define MTK_NOR_CMD_READ		BIT(0)
28 #define MTK_NOR_CMD_MASK		GENMASK(5, 0)
29 
30 #define MTK_NOR_REG_PRG_CNT		0x04
31 #define MTK_NOR_PRG_CNT_MAX		56
32 #define MTK_NOR_REG_RDATA		0x0c
33 
34 #define MTK_NOR_REG_RADR0		0x10
35 #define MTK_NOR_REG_RADR(n)		(MTK_NOR_REG_RADR0 + 4 * (n))
36 #define MTK_NOR_REG_RADR3		0xc8
37 
38 #define MTK_NOR_REG_WDATA		0x1c
39 
40 #define MTK_NOR_REG_PRGDATA0		0x20
41 #define MTK_NOR_REG_PRGDATA(n)		(MTK_NOR_REG_PRGDATA0 + 4 * (n))
42 #define MTK_NOR_REG_PRGDATA_MAX		5
43 
44 #define MTK_NOR_REG_SHIFT0		0x38
45 #define MTK_NOR_REG_SHIFT(n)		(MTK_NOR_REG_SHIFT0 + 4 * (n))
46 #define MTK_NOR_REG_SHIFT_MAX		9
47 
48 #define MTK_NOR_REG_CFG1		0x60
49 #define MTK_NOR_FAST_READ		BIT(0)
50 
51 #define MTK_NOR_REG_CFG2		0x64
52 #define MTK_NOR_WR_CUSTOM_OP_EN		BIT(4)
53 #define MTK_NOR_WR_BUF_EN		BIT(0)
54 
55 #define MTK_NOR_REG_PP_DATA		0x98
56 
57 #define MTK_NOR_REG_IRQ_STAT		0xa8
58 #define MTK_NOR_REG_IRQ_EN		0xac
59 #define MTK_NOR_IRQ_DMA			BIT(7)
60 #define MTK_NOR_IRQ_MASK		GENMASK(7, 0)
61 
62 #define MTK_NOR_REG_CFG3		0xb4
63 #define MTK_NOR_DISABLE_WREN		BIT(7)
64 #define MTK_NOR_DISABLE_SR_POLL		BIT(5)
65 
66 #define MTK_NOR_REG_WP			0xc4
67 #define MTK_NOR_ENABLE_SF_CMD		0x30
68 
69 #define MTK_NOR_REG_BUSCFG		0xcc
70 #define MTK_NOR_4B_ADDR			BIT(4)
71 #define MTK_NOR_QUAD_ADDR		BIT(3)
72 #define MTK_NOR_QUAD_READ		BIT(2)
73 #define MTK_NOR_DUAL_ADDR		BIT(1)
74 #define MTK_NOR_DUAL_READ		BIT(0)
75 #define MTK_NOR_BUS_MODE_MASK		GENMASK(4, 0)
76 
77 #define MTK_NOR_REG_DMA_CTL		0x718
78 #define MTK_NOR_DMA_START		BIT(0)
79 
80 #define MTK_NOR_REG_DMA_FADR		0x71c
81 #define MTK_NOR_REG_DMA_DADR		0x720
82 #define MTK_NOR_REG_DMA_END_DADR	0x724
83 #define MTK_NOR_REG_DMA_DADR_HB		0x738
84 #define MTK_NOR_REG_DMA_END_DADR_HB	0x73c
85 
86 #define MTK_NOR_PRG_MAX_SIZE		6
87 // Reading DMA src/dst addresses have to be 16-byte aligned
88 #define MTK_NOR_DMA_ALIGN		16
89 #define MTK_NOR_DMA_ALIGN_MASK		(MTK_NOR_DMA_ALIGN - 1)
90 // and we allocate a bounce buffer if destination address isn't aligned.
91 #define MTK_NOR_BOUNCE_BUF_SIZE		PAGE_SIZE
92 
93 // Buffered page program can do one 128-byte transfer
94 #define MTK_NOR_PP_SIZE			128
95 
96 #define CLK_TO_US(sp, clkcnt)		DIV_ROUND_UP(clkcnt, sp->spi_freq / 1000000)
97 
98 struct mtk_nor {
99 	struct spi_controller *ctlr;
100 	struct device *dev;
101 	void __iomem *base;
102 	u8 *buffer;
103 	dma_addr_t buffer_dma;
104 	struct clk *spi_clk;
105 	struct clk *ctlr_clk;
106 	struct clk *axi_clk;
107 	unsigned int spi_freq;
108 	bool wbuf_en;
109 	bool has_irq;
110 	bool high_dma;
111 	struct completion op_done;
112 };
113 
114 static inline void mtk_nor_rmw(struct mtk_nor *sp, u32 reg, u32 set, u32 clr)
115 {
116 	u32 val = readl(sp->base + reg);
117 
118 	val &= ~clr;
119 	val |= set;
120 	writel(val, sp->base + reg);
121 }
122 
123 static inline int mtk_nor_cmd_exec(struct mtk_nor *sp, u32 cmd, ulong clk)
124 {
125 	ulong delay = CLK_TO_US(sp, clk);
126 	u32 reg;
127 	int ret;
128 
129 	writel(cmd, sp->base + MTK_NOR_REG_CMD);
130 	ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CMD, reg, !(reg & cmd),
131 				 delay / 3, (delay + 1) * 200);
132 	if (ret < 0)
133 		dev_err(sp->dev, "command %u timeout.\n", cmd);
134 	return ret;
135 }
136 
137 static void mtk_nor_set_addr(struct mtk_nor *sp, const struct spi_mem_op *op)
138 {
139 	u32 addr = op->addr.val;
140 	int i;
141 
142 	for (i = 0; i < 3; i++) {
143 		writeb(addr & 0xff, sp->base + MTK_NOR_REG_RADR(i));
144 		addr >>= 8;
145 	}
146 	if (op->addr.nbytes == 4) {
147 		writeb(addr & 0xff, sp->base + MTK_NOR_REG_RADR3);
148 		mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, MTK_NOR_4B_ADDR, 0);
149 	} else {
150 		mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, 0, MTK_NOR_4B_ADDR);
151 	}
152 }
153 
154 static bool need_bounce(struct mtk_nor *sp, const struct spi_mem_op *op)
155 {
156 	return ((uintptr_t)op->data.buf.in & MTK_NOR_DMA_ALIGN_MASK);
157 }
158 
159 static bool mtk_nor_match_read(const struct spi_mem_op *op)
160 {
161 	int dummy = 0;
162 
163 	if (op->dummy.buswidth)
164 		dummy = op->dummy.nbytes * BITS_PER_BYTE / op->dummy.buswidth;
165 
166 	if ((op->data.buswidth == 2) || (op->data.buswidth == 4)) {
167 		if (op->addr.buswidth == 1)
168 			return dummy == 8;
169 		else if (op->addr.buswidth == 2)
170 			return dummy == 4;
171 		else if (op->addr.buswidth == 4)
172 			return dummy == 6;
173 	} else if ((op->addr.buswidth == 1) && (op->data.buswidth == 1)) {
174 		if (op->cmd.opcode == 0x03)
175 			return dummy == 0;
176 		else if (op->cmd.opcode == 0x0b)
177 			return dummy == 8;
178 	}
179 	return false;
180 }
181 
182 static bool mtk_nor_match_prg(const struct spi_mem_op *op)
183 {
184 	int tx_len, rx_len, prg_len, prg_left;
185 
186 	// prg mode is spi-only.
187 	if ((op->cmd.buswidth > 1) || (op->addr.buswidth > 1) ||
188 	    (op->dummy.buswidth > 1) || (op->data.buswidth > 1))
189 		return false;
190 
191 	tx_len = op->cmd.nbytes + op->addr.nbytes;
192 
193 	if (op->data.dir == SPI_MEM_DATA_OUT) {
194 		// count dummy bytes only if we need to write data after it
195 		tx_len += op->dummy.nbytes;
196 
197 		// leave at least one byte for data
198 		if (tx_len > MTK_NOR_REG_PRGDATA_MAX)
199 			return false;
200 
201 		// if there's no addr, meaning adjust_op_size is impossible,
202 		// check data length as well.
203 		if ((!op->addr.nbytes) &&
204 		    (tx_len + op->data.nbytes > MTK_NOR_REG_PRGDATA_MAX + 1))
205 			return false;
206 	} else if (op->data.dir == SPI_MEM_DATA_IN) {
207 		if (tx_len > MTK_NOR_REG_PRGDATA_MAX + 1)
208 			return false;
209 
210 		rx_len = op->data.nbytes;
211 		prg_left = MTK_NOR_PRG_CNT_MAX / 8 - tx_len - op->dummy.nbytes;
212 		if (prg_left > MTK_NOR_REG_SHIFT_MAX + 1)
213 			prg_left = MTK_NOR_REG_SHIFT_MAX + 1;
214 		if (rx_len > prg_left) {
215 			if (!op->addr.nbytes)
216 				return false;
217 			rx_len = prg_left;
218 		}
219 
220 		prg_len = tx_len + op->dummy.nbytes + rx_len;
221 		if (prg_len > MTK_NOR_PRG_CNT_MAX / 8)
222 			return false;
223 	} else {
224 		prg_len = tx_len + op->dummy.nbytes;
225 		if (prg_len > MTK_NOR_PRG_CNT_MAX / 8)
226 			return false;
227 	}
228 	return true;
229 }
230 
231 static void mtk_nor_adj_prg_size(struct spi_mem_op *op)
232 {
233 	int tx_len, tx_left, prg_left;
234 
235 	tx_len = op->cmd.nbytes + op->addr.nbytes;
236 	if (op->data.dir == SPI_MEM_DATA_OUT) {
237 		tx_len += op->dummy.nbytes;
238 		tx_left = MTK_NOR_REG_PRGDATA_MAX + 1 - tx_len;
239 		if (op->data.nbytes > tx_left)
240 			op->data.nbytes = tx_left;
241 	} else if (op->data.dir == SPI_MEM_DATA_IN) {
242 		prg_left = MTK_NOR_PRG_CNT_MAX / 8 - tx_len - op->dummy.nbytes;
243 		if (prg_left > MTK_NOR_REG_SHIFT_MAX + 1)
244 			prg_left = MTK_NOR_REG_SHIFT_MAX + 1;
245 		if (op->data.nbytes > prg_left)
246 			op->data.nbytes = prg_left;
247 	}
248 }
249 
250 static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
251 {
252 	struct mtk_nor *sp = spi_controller_get_devdata(mem->spi->master);
253 
254 	if (!op->data.nbytes)
255 		return 0;
256 
257 	if ((op->addr.nbytes == 3) || (op->addr.nbytes == 4)) {
258 		if ((op->data.dir == SPI_MEM_DATA_IN) &&
259 		    mtk_nor_match_read(op)) {
260 			// limit size to prevent timeout calculation overflow
261 			if (op->data.nbytes > 0x400000)
262 				op->data.nbytes = 0x400000;
263 
264 			if ((op->addr.val & MTK_NOR_DMA_ALIGN_MASK) ||
265 			    (op->data.nbytes < MTK_NOR_DMA_ALIGN))
266 				op->data.nbytes = 1;
267 			else if (!need_bounce(sp, op))
268 				op->data.nbytes &= ~MTK_NOR_DMA_ALIGN_MASK;
269 			else if (op->data.nbytes > MTK_NOR_BOUNCE_BUF_SIZE)
270 				op->data.nbytes = MTK_NOR_BOUNCE_BUF_SIZE;
271 			return 0;
272 		} else if (op->data.dir == SPI_MEM_DATA_OUT) {
273 			if (op->data.nbytes >= MTK_NOR_PP_SIZE)
274 				op->data.nbytes = MTK_NOR_PP_SIZE;
275 			else
276 				op->data.nbytes = 1;
277 			return 0;
278 		}
279 	}
280 
281 	mtk_nor_adj_prg_size(op);
282 	return 0;
283 }
284 
285 static bool mtk_nor_supports_op(struct spi_mem *mem,
286 				const struct spi_mem_op *op)
287 {
288 	if (!spi_mem_default_supports_op(mem, op))
289 		return false;
290 
291 	if (op->cmd.buswidth != 1)
292 		return false;
293 
294 	if ((op->addr.nbytes == 3) || (op->addr.nbytes == 4)) {
295 		switch(op->data.dir) {
296 		case SPI_MEM_DATA_IN:
297 			if (mtk_nor_match_read(op))
298 				return true;
299 			break;
300 		case SPI_MEM_DATA_OUT:
301 			if ((op->addr.buswidth == 1) &&
302 			    (op->dummy.nbytes == 0) &&
303 			    (op->data.buswidth == 1))
304 				return true;
305 			break;
306 		default:
307 			break;
308 		}
309 	}
310 
311 	return mtk_nor_match_prg(op);
312 }
313 
314 static void mtk_nor_setup_bus(struct mtk_nor *sp, const struct spi_mem_op *op)
315 {
316 	u32 reg = 0;
317 
318 	if (op->addr.nbytes == 4)
319 		reg |= MTK_NOR_4B_ADDR;
320 
321 	if (op->data.buswidth == 4) {
322 		reg |= MTK_NOR_QUAD_READ;
323 		writeb(op->cmd.opcode, sp->base + MTK_NOR_REG_PRGDATA(4));
324 		if (op->addr.buswidth == 4)
325 			reg |= MTK_NOR_QUAD_ADDR;
326 	} else if (op->data.buswidth == 2) {
327 		reg |= MTK_NOR_DUAL_READ;
328 		writeb(op->cmd.opcode, sp->base + MTK_NOR_REG_PRGDATA(3));
329 		if (op->addr.buswidth == 2)
330 			reg |= MTK_NOR_DUAL_ADDR;
331 	} else {
332 		if (op->cmd.opcode == 0x0b)
333 			mtk_nor_rmw(sp, MTK_NOR_REG_CFG1, MTK_NOR_FAST_READ, 0);
334 		else
335 			mtk_nor_rmw(sp, MTK_NOR_REG_CFG1, 0, MTK_NOR_FAST_READ);
336 	}
337 	mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, reg, MTK_NOR_BUS_MODE_MASK);
338 }
339 
340 static int mtk_nor_dma_exec(struct mtk_nor *sp, u32 from, unsigned int length,
341 			    dma_addr_t dma_addr)
342 {
343 	int ret = 0;
344 	ulong delay;
345 	u32 reg;
346 
347 	writel(from, sp->base + MTK_NOR_REG_DMA_FADR);
348 	writel(dma_addr, sp->base + MTK_NOR_REG_DMA_DADR);
349 	writel(dma_addr + length, sp->base + MTK_NOR_REG_DMA_END_DADR);
350 
351 	if (sp->high_dma) {
352 		writel(upper_32_bits(dma_addr),
353 		       sp->base + MTK_NOR_REG_DMA_DADR_HB);
354 		writel(upper_32_bits(dma_addr + length),
355 		       sp->base + MTK_NOR_REG_DMA_END_DADR_HB);
356 	}
357 
358 	if (sp->has_irq) {
359 		reinit_completion(&sp->op_done);
360 		mtk_nor_rmw(sp, MTK_NOR_REG_IRQ_EN, MTK_NOR_IRQ_DMA, 0);
361 	}
362 
363 	mtk_nor_rmw(sp, MTK_NOR_REG_DMA_CTL, MTK_NOR_DMA_START, 0);
364 
365 	delay = CLK_TO_US(sp, (length + 5) * BITS_PER_BYTE);
366 
367 	if (sp->has_irq) {
368 		if (!wait_for_completion_timeout(&sp->op_done,
369 						 (delay + 1) * 100))
370 			ret = -ETIMEDOUT;
371 	} else {
372 		ret = readl_poll_timeout(sp->base + MTK_NOR_REG_DMA_CTL, reg,
373 					 !(reg & MTK_NOR_DMA_START), delay / 3,
374 					 (delay + 1) * 100);
375 	}
376 
377 	if (ret < 0)
378 		dev_err(sp->dev, "dma read timeout.\n");
379 
380 	return ret;
381 }
382 
383 static int mtk_nor_read_bounce(struct mtk_nor *sp, const struct spi_mem_op *op)
384 {
385 	unsigned int rdlen;
386 	int ret;
387 
388 	if (op->data.nbytes & MTK_NOR_DMA_ALIGN_MASK)
389 		rdlen = (op->data.nbytes + MTK_NOR_DMA_ALIGN) & ~MTK_NOR_DMA_ALIGN_MASK;
390 	else
391 		rdlen = op->data.nbytes;
392 
393 	ret = mtk_nor_dma_exec(sp, op->addr.val, rdlen, sp->buffer_dma);
394 
395 	if (!ret)
396 		memcpy(op->data.buf.in, sp->buffer, op->data.nbytes);
397 
398 	return ret;
399 }
400 
401 static int mtk_nor_read_dma(struct mtk_nor *sp, const struct spi_mem_op *op)
402 {
403 	int ret;
404 	dma_addr_t dma_addr;
405 
406 	if (need_bounce(sp, op))
407 		return mtk_nor_read_bounce(sp, op);
408 
409 	dma_addr = dma_map_single(sp->dev, op->data.buf.in,
410 				  op->data.nbytes, DMA_FROM_DEVICE);
411 
412 	if (dma_mapping_error(sp->dev, dma_addr))
413 		return -EINVAL;
414 
415 	ret = mtk_nor_dma_exec(sp, op->addr.val, op->data.nbytes, dma_addr);
416 
417 	dma_unmap_single(sp->dev, dma_addr, op->data.nbytes, DMA_FROM_DEVICE);
418 
419 	return ret;
420 }
421 
422 static int mtk_nor_read_pio(struct mtk_nor *sp, const struct spi_mem_op *op)
423 {
424 	u8 *buf = op->data.buf.in;
425 	int ret;
426 
427 	ret = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_READ, 6 * BITS_PER_BYTE);
428 	if (!ret)
429 		buf[0] = readb(sp->base + MTK_NOR_REG_RDATA);
430 	return ret;
431 }
432 
433 static int mtk_nor_write_buffer_enable(struct mtk_nor *sp)
434 {
435 	int ret;
436 	u32 val;
437 
438 	if (sp->wbuf_en)
439 		return 0;
440 
441 	val = readl(sp->base + MTK_NOR_REG_CFG2);
442 	writel(val | MTK_NOR_WR_BUF_EN, sp->base + MTK_NOR_REG_CFG2);
443 	ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CFG2, val,
444 				 val & MTK_NOR_WR_BUF_EN, 0, 10000);
445 	if (!ret)
446 		sp->wbuf_en = true;
447 	return ret;
448 }
449 
450 static int mtk_nor_write_buffer_disable(struct mtk_nor *sp)
451 {
452 	int ret;
453 	u32 val;
454 
455 	if (!sp->wbuf_en)
456 		return 0;
457 	val = readl(sp->base + MTK_NOR_REG_CFG2);
458 	writel(val & ~MTK_NOR_WR_BUF_EN, sp->base + MTK_NOR_REG_CFG2);
459 	ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CFG2, val,
460 				 !(val & MTK_NOR_WR_BUF_EN), 0, 10000);
461 	if (!ret)
462 		sp->wbuf_en = false;
463 	return ret;
464 }
465 
466 static int mtk_nor_pp_buffered(struct mtk_nor *sp, const struct spi_mem_op *op)
467 {
468 	const u8 *buf = op->data.buf.out;
469 	u32 val;
470 	int ret, i;
471 
472 	ret = mtk_nor_write_buffer_enable(sp);
473 	if (ret < 0)
474 		return ret;
475 
476 	for (i = 0; i < op->data.nbytes; i += 4) {
477 		val = buf[i + 3] << 24 | buf[i + 2] << 16 | buf[i + 1] << 8 |
478 		      buf[i];
479 		writel(val, sp->base + MTK_NOR_REG_PP_DATA);
480 	}
481 	return mtk_nor_cmd_exec(sp, MTK_NOR_CMD_WRITE,
482 				(op->data.nbytes + 5) * BITS_PER_BYTE);
483 }
484 
485 static int mtk_nor_pp_unbuffered(struct mtk_nor *sp,
486 				 const struct spi_mem_op *op)
487 {
488 	const u8 *buf = op->data.buf.out;
489 	int ret;
490 
491 	ret = mtk_nor_write_buffer_disable(sp);
492 	if (ret < 0)
493 		return ret;
494 	writeb(buf[0], sp->base + MTK_NOR_REG_WDATA);
495 	return mtk_nor_cmd_exec(sp, MTK_NOR_CMD_WRITE, 6 * BITS_PER_BYTE);
496 }
497 
498 static int mtk_nor_spi_mem_prg(struct mtk_nor *sp, const struct spi_mem_op *op)
499 {
500 	int rx_len = 0;
501 	int reg_offset = MTK_NOR_REG_PRGDATA_MAX;
502 	int tx_len, prg_len;
503 	int i, ret;
504 	void __iomem *reg;
505 	u8 bufbyte;
506 
507 	tx_len = op->cmd.nbytes + op->addr.nbytes;
508 
509 	// count dummy bytes only if we need to write data after it
510 	if (op->data.dir == SPI_MEM_DATA_OUT)
511 		tx_len += op->dummy.nbytes + op->data.nbytes;
512 	else if (op->data.dir == SPI_MEM_DATA_IN)
513 		rx_len = op->data.nbytes;
514 
515 	prg_len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes +
516 		  op->data.nbytes;
517 
518 	// an invalid op may reach here if the caller calls exec_op without
519 	// adjust_op_size. return -EINVAL instead of -ENOTSUPP so that
520 	// spi-mem won't try this op again with generic spi transfers.
521 	if ((tx_len > MTK_NOR_REG_PRGDATA_MAX + 1) ||
522 	    (rx_len > MTK_NOR_REG_SHIFT_MAX + 1) ||
523 	    (prg_len > MTK_NOR_PRG_CNT_MAX / 8))
524 		return -EINVAL;
525 
526 	// fill tx data
527 	for (i = op->cmd.nbytes; i > 0; i--, reg_offset--) {
528 		reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
529 		bufbyte = (op->cmd.opcode >> ((i - 1) * BITS_PER_BYTE)) & 0xff;
530 		writeb(bufbyte, reg);
531 	}
532 
533 	for (i = op->addr.nbytes; i > 0; i--, reg_offset--) {
534 		reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
535 		bufbyte = (op->addr.val >> ((i - 1) * BITS_PER_BYTE)) & 0xff;
536 		writeb(bufbyte, reg);
537 	}
538 
539 	if (op->data.dir == SPI_MEM_DATA_OUT) {
540 		for (i = 0; i < op->dummy.nbytes; i++, reg_offset--) {
541 			reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
542 			writeb(0, reg);
543 		}
544 
545 		for (i = 0; i < op->data.nbytes; i++, reg_offset--) {
546 			reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
547 			writeb(((const u8 *)(op->data.buf.out))[i], reg);
548 		}
549 	}
550 
551 	for (; reg_offset >= 0; reg_offset--) {
552 		reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
553 		writeb(0, reg);
554 	}
555 
556 	// trigger op
557 	writel(prg_len * BITS_PER_BYTE, sp->base + MTK_NOR_REG_PRG_CNT);
558 	ret = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_PROGRAM,
559 			       prg_len * BITS_PER_BYTE);
560 	if (ret)
561 		return ret;
562 
563 	// fetch read data
564 	reg_offset = 0;
565 	if (op->data.dir == SPI_MEM_DATA_IN) {
566 		for (i = op->data.nbytes - 1; i >= 0; i--, reg_offset++) {
567 			reg = sp->base + MTK_NOR_REG_SHIFT(reg_offset);
568 			((u8 *)(op->data.buf.in))[i] = readb(reg);
569 		}
570 	}
571 
572 	return 0;
573 }
574 
575 static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
576 {
577 	struct mtk_nor *sp = spi_controller_get_devdata(mem->spi->master);
578 	int ret;
579 
580 	if ((op->data.nbytes == 0) ||
581 	    ((op->addr.nbytes != 3) && (op->addr.nbytes != 4)))
582 		return mtk_nor_spi_mem_prg(sp, op);
583 
584 	if (op->data.dir == SPI_MEM_DATA_OUT) {
585 		mtk_nor_set_addr(sp, op);
586 		writeb(op->cmd.opcode, sp->base + MTK_NOR_REG_PRGDATA0);
587 		if (op->data.nbytes == MTK_NOR_PP_SIZE)
588 			return mtk_nor_pp_buffered(sp, op);
589 		return mtk_nor_pp_unbuffered(sp, op);
590 	}
591 
592 	if ((op->data.dir == SPI_MEM_DATA_IN) && mtk_nor_match_read(op)) {
593 		ret = mtk_nor_write_buffer_disable(sp);
594 		if (ret < 0)
595 			return ret;
596 		mtk_nor_setup_bus(sp, op);
597 		if (op->data.nbytes == 1) {
598 			mtk_nor_set_addr(sp, op);
599 			return mtk_nor_read_pio(sp, op);
600 		} else {
601 			return mtk_nor_read_dma(sp, op);
602 		}
603 	}
604 
605 	return mtk_nor_spi_mem_prg(sp, op);
606 }
607 
608 static int mtk_nor_setup(struct spi_device *spi)
609 {
610 	struct mtk_nor *sp = spi_controller_get_devdata(spi->master);
611 
612 	if (spi->max_speed_hz && (spi->max_speed_hz < sp->spi_freq)) {
613 		dev_err(&spi->dev, "spi clock should be %u Hz.\n",
614 			sp->spi_freq);
615 		return -EINVAL;
616 	}
617 	spi->max_speed_hz = sp->spi_freq;
618 
619 	return 0;
620 }
621 
622 static int mtk_nor_transfer_one_message(struct spi_controller *master,
623 					struct spi_message *m)
624 {
625 	struct mtk_nor *sp = spi_controller_get_devdata(master);
626 	struct spi_transfer *t = NULL;
627 	unsigned long trx_len = 0;
628 	int stat = 0;
629 	int reg_offset = MTK_NOR_REG_PRGDATA_MAX;
630 	void __iomem *reg;
631 	const u8 *txbuf;
632 	u8 *rxbuf;
633 	int i;
634 
635 	list_for_each_entry(t, &m->transfers, transfer_list) {
636 		txbuf = t->tx_buf;
637 		for (i = 0; i < t->len; i++, reg_offset--) {
638 			reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
639 			if (txbuf)
640 				writeb(txbuf[i], reg);
641 			else
642 				writeb(0, reg);
643 		}
644 		trx_len += t->len;
645 	}
646 
647 	writel(trx_len * BITS_PER_BYTE, sp->base + MTK_NOR_REG_PRG_CNT);
648 
649 	stat = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_PROGRAM,
650 				trx_len * BITS_PER_BYTE);
651 	if (stat < 0)
652 		goto msg_done;
653 
654 	reg_offset = trx_len - 1;
655 	list_for_each_entry(t, &m->transfers, transfer_list) {
656 		rxbuf = t->rx_buf;
657 		for (i = 0; i < t->len; i++, reg_offset--) {
658 			reg = sp->base + MTK_NOR_REG_SHIFT(reg_offset);
659 			if (rxbuf)
660 				rxbuf[i] = readb(reg);
661 		}
662 	}
663 
664 	m->actual_length = trx_len;
665 msg_done:
666 	m->status = stat;
667 	spi_finalize_current_message(master);
668 
669 	return 0;
670 }
671 
672 static void mtk_nor_disable_clk(struct mtk_nor *sp)
673 {
674 	clk_disable_unprepare(sp->spi_clk);
675 	clk_disable_unprepare(sp->ctlr_clk);
676 	clk_disable_unprepare(sp->axi_clk);
677 }
678 
679 static int mtk_nor_enable_clk(struct mtk_nor *sp)
680 {
681 	int ret;
682 
683 	ret = clk_prepare_enable(sp->spi_clk);
684 	if (ret)
685 		return ret;
686 
687 	ret = clk_prepare_enable(sp->ctlr_clk);
688 	if (ret) {
689 		clk_disable_unprepare(sp->spi_clk);
690 		return ret;
691 	}
692 
693 	ret = clk_prepare_enable(sp->axi_clk);
694 	if (ret) {
695 		clk_disable_unprepare(sp->spi_clk);
696 		clk_disable_unprepare(sp->ctlr_clk);
697 		return ret;
698 	}
699 
700 	return 0;
701 }
702 
703 static void mtk_nor_init(struct mtk_nor *sp)
704 {
705 	writel(0, sp->base + MTK_NOR_REG_IRQ_EN);
706 	writel(MTK_NOR_IRQ_MASK, sp->base + MTK_NOR_REG_IRQ_STAT);
707 
708 	writel(MTK_NOR_ENABLE_SF_CMD, sp->base + MTK_NOR_REG_WP);
709 	mtk_nor_rmw(sp, MTK_NOR_REG_CFG2, MTK_NOR_WR_CUSTOM_OP_EN, 0);
710 	mtk_nor_rmw(sp, MTK_NOR_REG_CFG3,
711 		    MTK_NOR_DISABLE_WREN | MTK_NOR_DISABLE_SR_POLL, 0);
712 }
713 
714 static irqreturn_t mtk_nor_irq_handler(int irq, void *data)
715 {
716 	struct mtk_nor *sp = data;
717 	u32 irq_status, irq_enabled;
718 
719 	irq_status = readl(sp->base + MTK_NOR_REG_IRQ_STAT);
720 	irq_enabled = readl(sp->base + MTK_NOR_REG_IRQ_EN);
721 	// write status back to clear interrupt
722 	writel(irq_status, sp->base + MTK_NOR_REG_IRQ_STAT);
723 
724 	if (!(irq_status & irq_enabled))
725 		return IRQ_NONE;
726 
727 	if (irq_status & MTK_NOR_IRQ_DMA) {
728 		complete(&sp->op_done);
729 		writel(0, sp->base + MTK_NOR_REG_IRQ_EN);
730 	}
731 
732 	return IRQ_HANDLED;
733 }
734 
735 static size_t mtk_max_msg_size(struct spi_device *spi)
736 {
737 	return MTK_NOR_PRG_MAX_SIZE;
738 }
739 
740 static const struct spi_controller_mem_ops mtk_nor_mem_ops = {
741 	.adjust_op_size = mtk_nor_adjust_op_size,
742 	.supports_op = mtk_nor_supports_op,
743 	.exec_op = mtk_nor_exec_op
744 };
745 
746 static const struct of_device_id mtk_nor_match[] = {
747 	{ .compatible = "mediatek,mt8192-nor", .data = (void *)36 },
748 	{ .compatible = "mediatek,mt8173-nor", .data = (void *)32 },
749 	{ /* sentinel */ }
750 };
751 MODULE_DEVICE_TABLE(of, mtk_nor_match);
752 
753 static int mtk_nor_probe(struct platform_device *pdev)
754 {
755 	struct spi_controller *ctlr;
756 	struct mtk_nor *sp;
757 	void __iomem *base;
758 	struct clk *spi_clk, *ctlr_clk, *axi_clk;
759 	int ret, irq;
760 	unsigned long dma_bits;
761 
762 	base = devm_platform_ioremap_resource(pdev, 0);
763 	if (IS_ERR(base))
764 		return PTR_ERR(base);
765 
766 	spi_clk = devm_clk_get(&pdev->dev, "spi");
767 	if (IS_ERR(spi_clk))
768 		return PTR_ERR(spi_clk);
769 
770 	ctlr_clk = devm_clk_get(&pdev->dev, "sf");
771 	if (IS_ERR(ctlr_clk))
772 		return PTR_ERR(ctlr_clk);
773 
774 	axi_clk = devm_clk_get_optional(&pdev->dev, "axi");
775 	if (IS_ERR(axi_clk))
776 		return PTR_ERR(axi_clk);
777 
778 	dma_bits = (unsigned long)of_device_get_match_data(&pdev->dev);
779 	if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(dma_bits))) {
780 		dev_err(&pdev->dev, "failed to set dma mask(%lu)\n", dma_bits);
781 		return -EINVAL;
782 	}
783 
784 	ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*sp));
785 	if (!ctlr) {
786 		dev_err(&pdev->dev, "failed to allocate spi controller\n");
787 		return -ENOMEM;
788 	}
789 
790 	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
791 	ctlr->dev.of_node = pdev->dev.of_node;
792 	ctlr->max_message_size = mtk_max_msg_size;
793 	ctlr->mem_ops = &mtk_nor_mem_ops;
794 	ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD | SPI_TX_DUAL | SPI_TX_QUAD;
795 	ctlr->num_chipselect = 1;
796 	ctlr->setup = mtk_nor_setup;
797 	ctlr->transfer_one_message = mtk_nor_transfer_one_message;
798 	ctlr->auto_runtime_pm = true;
799 
800 	dev_set_drvdata(&pdev->dev, ctlr);
801 
802 	sp = spi_controller_get_devdata(ctlr);
803 	sp->base = base;
804 	sp->has_irq = false;
805 	sp->wbuf_en = false;
806 	sp->ctlr = ctlr;
807 	sp->dev = &pdev->dev;
808 	sp->spi_clk = spi_clk;
809 	sp->ctlr_clk = ctlr_clk;
810 	sp->axi_clk = axi_clk;
811 	sp->high_dma = (dma_bits > 32);
812 	sp->buffer = dmam_alloc_coherent(&pdev->dev,
813 				MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN,
814 				&sp->buffer_dma, GFP_KERNEL);
815 	if (!sp->buffer)
816 		return -ENOMEM;
817 
818 	if ((uintptr_t)sp->buffer & MTK_NOR_DMA_ALIGN_MASK) {
819 		dev_err(sp->dev, "misaligned allocation of internal buffer.\n");
820 		return -ENOMEM;
821 	}
822 
823 	ret = mtk_nor_enable_clk(sp);
824 	if (ret < 0)
825 		return ret;
826 
827 	sp->spi_freq = clk_get_rate(sp->spi_clk);
828 
829 	mtk_nor_init(sp);
830 
831 	irq = platform_get_irq_optional(pdev, 0);
832 
833 	if (irq < 0) {
834 		dev_warn(sp->dev, "IRQ not available.");
835 	} else {
836 		ret = devm_request_irq(sp->dev, irq, mtk_nor_irq_handler, 0,
837 				       pdev->name, sp);
838 		if (ret < 0) {
839 			dev_warn(sp->dev, "failed to request IRQ.");
840 		} else {
841 			init_completion(&sp->op_done);
842 			sp->has_irq = true;
843 		}
844 	}
845 
846 	pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
847 	pm_runtime_use_autosuspend(&pdev->dev);
848 	pm_runtime_set_active(&pdev->dev);
849 	pm_runtime_enable(&pdev->dev);
850 	pm_runtime_get_noresume(&pdev->dev);
851 
852 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
853 	if (ret < 0)
854 		goto err_probe;
855 
856 	pm_runtime_mark_last_busy(&pdev->dev);
857 	pm_runtime_put_autosuspend(&pdev->dev);
858 
859 	dev_info(&pdev->dev, "spi frequency: %d Hz\n", sp->spi_freq);
860 
861 	return 0;
862 
863 err_probe:
864 	pm_runtime_disable(&pdev->dev);
865 	pm_runtime_set_suspended(&pdev->dev);
866 	pm_runtime_dont_use_autosuspend(&pdev->dev);
867 
868 	mtk_nor_disable_clk(sp);
869 
870 	return ret;
871 }
872 
873 static int mtk_nor_remove(struct platform_device *pdev)
874 {
875 	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
876 	struct mtk_nor *sp = spi_controller_get_devdata(ctlr);
877 
878 	pm_runtime_disable(&pdev->dev);
879 	pm_runtime_set_suspended(&pdev->dev);
880 	pm_runtime_dont_use_autosuspend(&pdev->dev);
881 
882 	mtk_nor_disable_clk(sp);
883 
884 	return 0;
885 }
886 
887 static int __maybe_unused mtk_nor_runtime_suspend(struct device *dev)
888 {
889 	struct spi_controller *ctlr = dev_get_drvdata(dev);
890 	struct mtk_nor *sp = spi_controller_get_devdata(ctlr);
891 
892 	mtk_nor_disable_clk(sp);
893 
894 	return 0;
895 }
896 
897 static int __maybe_unused mtk_nor_runtime_resume(struct device *dev)
898 {
899 	struct spi_controller *ctlr = dev_get_drvdata(dev);
900 	struct mtk_nor *sp = spi_controller_get_devdata(ctlr);
901 
902 	return mtk_nor_enable_clk(sp);
903 }
904 
905 static int __maybe_unused mtk_nor_suspend(struct device *dev)
906 {
907 	return pm_runtime_force_suspend(dev);
908 }
909 
910 static int __maybe_unused mtk_nor_resume(struct device *dev)
911 {
912 	return pm_runtime_force_resume(dev);
913 }
914 
915 static const struct dev_pm_ops mtk_nor_pm_ops = {
916 	SET_RUNTIME_PM_OPS(mtk_nor_runtime_suspend,
917 			   mtk_nor_runtime_resume, NULL)
918 	SET_SYSTEM_SLEEP_PM_OPS(mtk_nor_suspend, mtk_nor_resume)
919 };
920 
921 static struct platform_driver mtk_nor_driver = {
922 	.driver = {
923 		.name = DRIVER_NAME,
924 		.of_match_table = mtk_nor_match,
925 		.pm = &mtk_nor_pm_ops,
926 	},
927 	.probe = mtk_nor_probe,
928 	.remove = mtk_nor_remove,
929 };
930 
931 module_platform_driver(mtk_nor_driver);
932 
933 MODULE_DESCRIPTION("Mediatek SPI NOR controller driver");
934 MODULE_AUTHOR("Chuanhong Guo <gch981213@gmail.com>");
935 MODULE_LICENSE("GPL v2");
936 MODULE_ALIAS("platform:" DRIVER_NAME);
937