xref: /openbmc/linux/drivers/spi/spi-mtk-nor.c (revision e40573a4)
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_caps {
99 	u8 dma_bits;
100 
101 	/* extra_dummy_bit is adding for the IP of new SoCs.
102 	 * Some new SoCs modify the timing of fetching registers' values
103 	 * and IDs of nor flash, they need a extra_dummy_bit which can add
104 	 * more clock cycles for fetching data.
105 	 */
106 	u8 extra_dummy_bit;
107 };
108 
109 struct mtk_nor {
110 	struct spi_controller *ctlr;
111 	struct device *dev;
112 	void __iomem *base;
113 	u8 *buffer;
114 	dma_addr_t buffer_dma;
115 	struct clk *spi_clk;
116 	struct clk *ctlr_clk;
117 	struct clk *axi_clk;
118 	struct clk *axi_s_clk;
119 	unsigned int spi_freq;
120 	bool wbuf_en;
121 	bool has_irq;
122 	bool high_dma;
123 	struct completion op_done;
124 	const struct mtk_nor_caps *caps;
125 };
126 
127 static inline void mtk_nor_rmw(struct mtk_nor *sp, u32 reg, u32 set, u32 clr)
128 {
129 	u32 val = readl(sp->base + reg);
130 
131 	val &= ~clr;
132 	val |= set;
133 	writel(val, sp->base + reg);
134 }
135 
136 static inline int mtk_nor_cmd_exec(struct mtk_nor *sp, u32 cmd, ulong clk)
137 {
138 	ulong delay = CLK_TO_US(sp, clk);
139 	u32 reg;
140 	int ret;
141 
142 	writel(cmd, sp->base + MTK_NOR_REG_CMD);
143 	ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CMD, reg, !(reg & cmd),
144 				 delay / 3, (delay + 1) * 200);
145 	if (ret < 0)
146 		dev_err(sp->dev, "command %u timeout.\n", cmd);
147 	return ret;
148 }
149 
150 static void mtk_nor_set_addr(struct mtk_nor *sp, const struct spi_mem_op *op)
151 {
152 	u32 addr = op->addr.val;
153 	int i;
154 
155 	for (i = 0; i < 3; i++) {
156 		writeb(addr & 0xff, sp->base + MTK_NOR_REG_RADR(i));
157 		addr >>= 8;
158 	}
159 	if (op->addr.nbytes == 4) {
160 		writeb(addr & 0xff, sp->base + MTK_NOR_REG_RADR3);
161 		mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, MTK_NOR_4B_ADDR, 0);
162 	} else {
163 		mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, 0, MTK_NOR_4B_ADDR);
164 	}
165 }
166 
167 static bool need_bounce(struct mtk_nor *sp, const struct spi_mem_op *op)
168 {
169 	return ((uintptr_t)op->data.buf.in & MTK_NOR_DMA_ALIGN_MASK);
170 }
171 
172 static bool mtk_nor_match_read(const struct spi_mem_op *op)
173 {
174 	int dummy = 0;
175 
176 	if (op->dummy.nbytes)
177 		dummy = op->dummy.nbytes * BITS_PER_BYTE / op->dummy.buswidth;
178 
179 	if ((op->data.buswidth == 2) || (op->data.buswidth == 4)) {
180 		if (op->addr.buswidth == 1)
181 			return dummy == 8;
182 		else if (op->addr.buswidth == 2)
183 			return dummy == 4;
184 		else if (op->addr.buswidth == 4)
185 			return dummy == 6;
186 	} else if ((op->addr.buswidth == 1) && (op->data.buswidth == 1)) {
187 		if (op->cmd.opcode == 0x03)
188 			return dummy == 0;
189 		else if (op->cmd.opcode == 0x0b)
190 			return dummy == 8;
191 	}
192 	return false;
193 }
194 
195 static bool mtk_nor_match_prg(const struct spi_mem_op *op)
196 {
197 	int tx_len, rx_len, prg_len, prg_left;
198 
199 	// prg mode is spi-only.
200 	if ((op->cmd.buswidth > 1) || (op->addr.buswidth > 1) ||
201 	    (op->dummy.buswidth > 1) || (op->data.buswidth > 1))
202 		return false;
203 
204 	tx_len = op->cmd.nbytes + op->addr.nbytes;
205 
206 	if (op->data.dir == SPI_MEM_DATA_OUT) {
207 		// count dummy bytes only if we need to write data after it
208 		tx_len += op->dummy.nbytes;
209 
210 		// leave at least one byte for data
211 		if (tx_len > MTK_NOR_REG_PRGDATA_MAX)
212 			return false;
213 
214 		// if there's no addr, meaning adjust_op_size is impossible,
215 		// check data length as well.
216 		if ((!op->addr.nbytes) &&
217 		    (tx_len + op->data.nbytes > MTK_NOR_REG_PRGDATA_MAX + 1))
218 			return false;
219 	} else if (op->data.dir == SPI_MEM_DATA_IN) {
220 		if (tx_len > MTK_NOR_REG_PRGDATA_MAX + 1)
221 			return false;
222 
223 		rx_len = op->data.nbytes;
224 		prg_left = MTK_NOR_PRG_CNT_MAX / 8 - tx_len - op->dummy.nbytes;
225 		if (prg_left > MTK_NOR_REG_SHIFT_MAX + 1)
226 			prg_left = MTK_NOR_REG_SHIFT_MAX + 1;
227 		if (rx_len > prg_left) {
228 			if (!op->addr.nbytes)
229 				return false;
230 			rx_len = prg_left;
231 		}
232 
233 		prg_len = tx_len + op->dummy.nbytes + rx_len;
234 		if (prg_len > MTK_NOR_PRG_CNT_MAX / 8)
235 			return false;
236 	} else {
237 		prg_len = tx_len + op->dummy.nbytes;
238 		if (prg_len > MTK_NOR_PRG_CNT_MAX / 8)
239 			return false;
240 	}
241 	return true;
242 }
243 
244 static void mtk_nor_adj_prg_size(struct spi_mem_op *op)
245 {
246 	int tx_len, tx_left, prg_left;
247 
248 	tx_len = op->cmd.nbytes + op->addr.nbytes;
249 	if (op->data.dir == SPI_MEM_DATA_OUT) {
250 		tx_len += op->dummy.nbytes;
251 		tx_left = MTK_NOR_REG_PRGDATA_MAX + 1 - tx_len;
252 		if (op->data.nbytes > tx_left)
253 			op->data.nbytes = tx_left;
254 	} else if (op->data.dir == SPI_MEM_DATA_IN) {
255 		prg_left = MTK_NOR_PRG_CNT_MAX / 8 - tx_len - op->dummy.nbytes;
256 		if (prg_left > MTK_NOR_REG_SHIFT_MAX + 1)
257 			prg_left = MTK_NOR_REG_SHIFT_MAX + 1;
258 		if (op->data.nbytes > prg_left)
259 			op->data.nbytes = prg_left;
260 	}
261 }
262 
263 static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
264 {
265 	struct mtk_nor *sp = spi_controller_get_devdata(mem->spi->master);
266 
267 	if (!op->data.nbytes)
268 		return 0;
269 
270 	if ((op->addr.nbytes == 3) || (op->addr.nbytes == 4)) {
271 		if ((op->data.dir == SPI_MEM_DATA_IN) &&
272 		    mtk_nor_match_read(op)) {
273 			// limit size to prevent timeout calculation overflow
274 			if (op->data.nbytes > 0x400000)
275 				op->data.nbytes = 0x400000;
276 
277 			if ((op->addr.val & MTK_NOR_DMA_ALIGN_MASK) ||
278 			    (op->data.nbytes < MTK_NOR_DMA_ALIGN))
279 				op->data.nbytes = 1;
280 			else if (!need_bounce(sp, op))
281 				op->data.nbytes &= ~MTK_NOR_DMA_ALIGN_MASK;
282 			else if (op->data.nbytes > MTK_NOR_BOUNCE_BUF_SIZE)
283 				op->data.nbytes = MTK_NOR_BOUNCE_BUF_SIZE;
284 			return 0;
285 		} else if (op->data.dir == SPI_MEM_DATA_OUT) {
286 			if (op->data.nbytes >= MTK_NOR_PP_SIZE)
287 				op->data.nbytes = MTK_NOR_PP_SIZE;
288 			else
289 				op->data.nbytes = 1;
290 			return 0;
291 		}
292 	}
293 
294 	mtk_nor_adj_prg_size(op);
295 	return 0;
296 }
297 
298 static bool mtk_nor_supports_op(struct spi_mem *mem,
299 				const struct spi_mem_op *op)
300 {
301 	if (!spi_mem_default_supports_op(mem, op))
302 		return false;
303 
304 	if (op->cmd.buswidth != 1)
305 		return false;
306 
307 	if ((op->addr.nbytes == 3) || (op->addr.nbytes == 4)) {
308 		switch (op->data.dir) {
309 		case SPI_MEM_DATA_IN:
310 			if (mtk_nor_match_read(op))
311 				return true;
312 			break;
313 		case SPI_MEM_DATA_OUT:
314 			if ((op->addr.buswidth == 1) &&
315 			    (op->dummy.nbytes == 0) &&
316 			    (op->data.buswidth == 1))
317 				return true;
318 			break;
319 		default:
320 			break;
321 		}
322 	}
323 
324 	return mtk_nor_match_prg(op);
325 }
326 
327 static void mtk_nor_setup_bus(struct mtk_nor *sp, const struct spi_mem_op *op)
328 {
329 	u32 reg = 0;
330 
331 	if (op->addr.nbytes == 4)
332 		reg |= MTK_NOR_4B_ADDR;
333 
334 	if (op->data.buswidth == 4) {
335 		reg |= MTK_NOR_QUAD_READ;
336 		writeb(op->cmd.opcode, sp->base + MTK_NOR_REG_PRGDATA(4));
337 		if (op->addr.buswidth == 4)
338 			reg |= MTK_NOR_QUAD_ADDR;
339 	} else if (op->data.buswidth == 2) {
340 		reg |= MTK_NOR_DUAL_READ;
341 		writeb(op->cmd.opcode, sp->base + MTK_NOR_REG_PRGDATA(3));
342 		if (op->addr.buswidth == 2)
343 			reg |= MTK_NOR_DUAL_ADDR;
344 	} else {
345 		if (op->cmd.opcode == 0x0b)
346 			mtk_nor_rmw(sp, MTK_NOR_REG_CFG1, MTK_NOR_FAST_READ, 0);
347 		else
348 			mtk_nor_rmw(sp, MTK_NOR_REG_CFG1, 0, MTK_NOR_FAST_READ);
349 	}
350 	mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, reg, MTK_NOR_BUS_MODE_MASK);
351 }
352 
353 static int mtk_nor_dma_exec(struct mtk_nor *sp, u32 from, unsigned int length,
354 			    dma_addr_t dma_addr)
355 {
356 	int ret = 0;
357 	ulong delay;
358 	u32 reg;
359 
360 	writel(from, sp->base + MTK_NOR_REG_DMA_FADR);
361 	writel(dma_addr, sp->base + MTK_NOR_REG_DMA_DADR);
362 	writel(dma_addr + length, sp->base + MTK_NOR_REG_DMA_END_DADR);
363 
364 	if (sp->high_dma) {
365 		writel(upper_32_bits(dma_addr),
366 		       sp->base + MTK_NOR_REG_DMA_DADR_HB);
367 		writel(upper_32_bits(dma_addr + length),
368 		       sp->base + MTK_NOR_REG_DMA_END_DADR_HB);
369 	}
370 
371 	if (sp->has_irq) {
372 		reinit_completion(&sp->op_done);
373 		mtk_nor_rmw(sp, MTK_NOR_REG_IRQ_EN, MTK_NOR_IRQ_DMA, 0);
374 	}
375 
376 	mtk_nor_rmw(sp, MTK_NOR_REG_DMA_CTL, MTK_NOR_DMA_START, 0);
377 
378 	delay = CLK_TO_US(sp, (length + 5) * BITS_PER_BYTE);
379 
380 	if (sp->has_irq) {
381 		if (!wait_for_completion_timeout(&sp->op_done,
382 						 (delay + 1) * 100))
383 			ret = -ETIMEDOUT;
384 	} else {
385 		ret = readl_poll_timeout(sp->base + MTK_NOR_REG_DMA_CTL, reg,
386 					 !(reg & MTK_NOR_DMA_START), delay / 3,
387 					 (delay + 1) * 100);
388 	}
389 
390 	if (ret < 0)
391 		dev_err(sp->dev, "dma read timeout.\n");
392 
393 	return ret;
394 }
395 
396 static int mtk_nor_read_bounce(struct mtk_nor *sp, const struct spi_mem_op *op)
397 {
398 	unsigned int rdlen;
399 	int ret;
400 
401 	if (op->data.nbytes & MTK_NOR_DMA_ALIGN_MASK)
402 		rdlen = (op->data.nbytes + MTK_NOR_DMA_ALIGN) & ~MTK_NOR_DMA_ALIGN_MASK;
403 	else
404 		rdlen = op->data.nbytes;
405 
406 	ret = mtk_nor_dma_exec(sp, op->addr.val, rdlen, sp->buffer_dma);
407 
408 	if (!ret)
409 		memcpy(op->data.buf.in, sp->buffer, op->data.nbytes);
410 
411 	return ret;
412 }
413 
414 static int mtk_nor_read_dma(struct mtk_nor *sp, const struct spi_mem_op *op)
415 {
416 	int ret;
417 	dma_addr_t dma_addr;
418 
419 	if (need_bounce(sp, op))
420 		return mtk_nor_read_bounce(sp, op);
421 
422 	dma_addr = dma_map_single(sp->dev, op->data.buf.in,
423 				  op->data.nbytes, DMA_FROM_DEVICE);
424 
425 	if (dma_mapping_error(sp->dev, dma_addr))
426 		return -EINVAL;
427 
428 	ret = mtk_nor_dma_exec(sp, op->addr.val, op->data.nbytes, dma_addr);
429 
430 	dma_unmap_single(sp->dev, dma_addr, op->data.nbytes, DMA_FROM_DEVICE);
431 
432 	return ret;
433 }
434 
435 static int mtk_nor_read_pio(struct mtk_nor *sp, const struct spi_mem_op *op)
436 {
437 	u8 *buf = op->data.buf.in;
438 	int ret;
439 
440 	ret = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_READ, 6 * BITS_PER_BYTE);
441 	if (!ret)
442 		buf[0] = readb(sp->base + MTK_NOR_REG_RDATA);
443 	return ret;
444 }
445 
446 static int mtk_nor_write_buffer_enable(struct mtk_nor *sp)
447 {
448 	int ret;
449 	u32 val;
450 
451 	if (sp->wbuf_en)
452 		return 0;
453 
454 	val = readl(sp->base + MTK_NOR_REG_CFG2);
455 	writel(val | MTK_NOR_WR_BUF_EN, sp->base + MTK_NOR_REG_CFG2);
456 	ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CFG2, val,
457 				 val & MTK_NOR_WR_BUF_EN, 0, 10000);
458 	if (!ret)
459 		sp->wbuf_en = true;
460 	return ret;
461 }
462 
463 static int mtk_nor_write_buffer_disable(struct mtk_nor *sp)
464 {
465 	int ret;
466 	u32 val;
467 
468 	if (!sp->wbuf_en)
469 		return 0;
470 	val = readl(sp->base + MTK_NOR_REG_CFG2);
471 	writel(val & ~MTK_NOR_WR_BUF_EN, sp->base + MTK_NOR_REG_CFG2);
472 	ret = readl_poll_timeout(sp->base + MTK_NOR_REG_CFG2, val,
473 				 !(val & MTK_NOR_WR_BUF_EN), 0, 10000);
474 	if (!ret)
475 		sp->wbuf_en = false;
476 	return ret;
477 }
478 
479 static int mtk_nor_pp_buffered(struct mtk_nor *sp, const struct spi_mem_op *op)
480 {
481 	const u8 *buf = op->data.buf.out;
482 	u32 val;
483 	int ret, i;
484 
485 	ret = mtk_nor_write_buffer_enable(sp);
486 	if (ret < 0)
487 		return ret;
488 
489 	for (i = 0; i < op->data.nbytes; i += 4) {
490 		val = buf[i + 3] << 24 | buf[i + 2] << 16 | buf[i + 1] << 8 |
491 		      buf[i];
492 		writel(val, sp->base + MTK_NOR_REG_PP_DATA);
493 	}
494 	return mtk_nor_cmd_exec(sp, MTK_NOR_CMD_WRITE,
495 				(op->data.nbytes + 5) * BITS_PER_BYTE);
496 }
497 
498 static int mtk_nor_pp_unbuffered(struct mtk_nor *sp,
499 				 const struct spi_mem_op *op)
500 {
501 	const u8 *buf = op->data.buf.out;
502 	int ret;
503 
504 	ret = mtk_nor_write_buffer_disable(sp);
505 	if (ret < 0)
506 		return ret;
507 	writeb(buf[0], sp->base + MTK_NOR_REG_WDATA);
508 	return mtk_nor_cmd_exec(sp, MTK_NOR_CMD_WRITE, 6 * BITS_PER_BYTE);
509 }
510 
511 static int mtk_nor_spi_mem_prg(struct mtk_nor *sp, const struct spi_mem_op *op)
512 {
513 	int rx_len = 0;
514 	int reg_offset = MTK_NOR_REG_PRGDATA_MAX;
515 	int tx_len, prg_len;
516 	int i, ret;
517 	void __iomem *reg;
518 	u8 bufbyte;
519 
520 	tx_len = op->cmd.nbytes + op->addr.nbytes;
521 
522 	// count dummy bytes only if we need to write data after it
523 	if (op->data.dir == SPI_MEM_DATA_OUT)
524 		tx_len += op->dummy.nbytes + op->data.nbytes;
525 	else if (op->data.dir == SPI_MEM_DATA_IN)
526 		rx_len = op->data.nbytes;
527 
528 	prg_len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes +
529 		  op->data.nbytes;
530 
531 	// an invalid op may reach here if the caller calls exec_op without
532 	// adjust_op_size. return -EINVAL instead of -ENOTSUPP so that
533 	// spi-mem won't try this op again with generic spi transfers.
534 	if ((tx_len > MTK_NOR_REG_PRGDATA_MAX + 1) ||
535 	    (rx_len > MTK_NOR_REG_SHIFT_MAX + 1) ||
536 	    (prg_len > MTK_NOR_PRG_CNT_MAX / 8))
537 		return -EINVAL;
538 
539 	// fill tx data
540 	for (i = op->cmd.nbytes; i > 0; i--, reg_offset--) {
541 		reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
542 		bufbyte = (op->cmd.opcode >> ((i - 1) * BITS_PER_BYTE)) & 0xff;
543 		writeb(bufbyte, reg);
544 	}
545 
546 	for (i = op->addr.nbytes; i > 0; i--, reg_offset--) {
547 		reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
548 		bufbyte = (op->addr.val >> ((i - 1) * BITS_PER_BYTE)) & 0xff;
549 		writeb(bufbyte, reg);
550 	}
551 
552 	if (op->data.dir == SPI_MEM_DATA_OUT) {
553 		for (i = 0; i < op->dummy.nbytes; i++, reg_offset--) {
554 			reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
555 			writeb(0, reg);
556 		}
557 
558 		for (i = 0; i < op->data.nbytes; i++, reg_offset--) {
559 			reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
560 			writeb(((const u8 *)(op->data.buf.out))[i], reg);
561 		}
562 	}
563 
564 	for (; reg_offset >= 0; reg_offset--) {
565 		reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
566 		writeb(0, reg);
567 	}
568 
569 	// trigger op
570 	if (rx_len)
571 		writel(prg_len * BITS_PER_BYTE + sp->caps->extra_dummy_bit,
572 		       sp->base + MTK_NOR_REG_PRG_CNT);
573 	else
574 		writel(prg_len * BITS_PER_BYTE, sp->base + MTK_NOR_REG_PRG_CNT);
575 
576 	ret = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_PROGRAM,
577 			       prg_len * BITS_PER_BYTE);
578 	if (ret)
579 		return ret;
580 
581 	// fetch read data
582 	reg_offset = 0;
583 	if (op->data.dir == SPI_MEM_DATA_IN) {
584 		for (i = op->data.nbytes - 1; i >= 0; i--, reg_offset++) {
585 			reg = sp->base + MTK_NOR_REG_SHIFT(reg_offset);
586 			((u8 *)(op->data.buf.in))[i] = readb(reg);
587 		}
588 	}
589 
590 	return 0;
591 }
592 
593 static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
594 {
595 	struct mtk_nor *sp = spi_controller_get_devdata(mem->spi->master);
596 	int ret;
597 
598 	if ((op->data.nbytes == 0) ||
599 	    ((op->addr.nbytes != 3) && (op->addr.nbytes != 4)))
600 		return mtk_nor_spi_mem_prg(sp, op);
601 
602 	if (op->data.dir == SPI_MEM_DATA_OUT) {
603 		mtk_nor_set_addr(sp, op);
604 		writeb(op->cmd.opcode, sp->base + MTK_NOR_REG_PRGDATA0);
605 		if (op->data.nbytes == MTK_NOR_PP_SIZE)
606 			return mtk_nor_pp_buffered(sp, op);
607 		return mtk_nor_pp_unbuffered(sp, op);
608 	}
609 
610 	if ((op->data.dir == SPI_MEM_DATA_IN) && mtk_nor_match_read(op)) {
611 		ret = mtk_nor_write_buffer_disable(sp);
612 		if (ret < 0)
613 			return ret;
614 		mtk_nor_setup_bus(sp, op);
615 		if (op->data.nbytes == 1) {
616 			mtk_nor_set_addr(sp, op);
617 			return mtk_nor_read_pio(sp, op);
618 		} else {
619 			return mtk_nor_read_dma(sp, op);
620 		}
621 	}
622 
623 	return mtk_nor_spi_mem_prg(sp, op);
624 }
625 
626 static int mtk_nor_setup(struct spi_device *spi)
627 {
628 	struct mtk_nor *sp = spi_controller_get_devdata(spi->master);
629 
630 	if (spi->max_speed_hz && (spi->max_speed_hz < sp->spi_freq)) {
631 		dev_err(&spi->dev, "spi clock should be %u Hz.\n",
632 			sp->spi_freq);
633 		return -EINVAL;
634 	}
635 	spi->max_speed_hz = sp->spi_freq;
636 
637 	return 0;
638 }
639 
640 static int mtk_nor_transfer_one_message(struct spi_controller *master,
641 					struct spi_message *m)
642 {
643 	struct mtk_nor *sp = spi_controller_get_devdata(master);
644 	struct spi_transfer *t = NULL;
645 	unsigned long trx_len = 0;
646 	int stat = 0;
647 	int reg_offset = MTK_NOR_REG_PRGDATA_MAX;
648 	void __iomem *reg;
649 	const u8 *txbuf;
650 	u8 *rxbuf;
651 	int i;
652 
653 	list_for_each_entry(t, &m->transfers, transfer_list) {
654 		txbuf = t->tx_buf;
655 		for (i = 0; i < t->len; i++, reg_offset--) {
656 			reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset);
657 			if (txbuf)
658 				writeb(txbuf[i], reg);
659 			else
660 				writeb(0, reg);
661 		}
662 		trx_len += t->len;
663 	}
664 
665 	writel(trx_len * BITS_PER_BYTE, sp->base + MTK_NOR_REG_PRG_CNT);
666 
667 	stat = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_PROGRAM,
668 				trx_len * BITS_PER_BYTE);
669 	if (stat < 0)
670 		goto msg_done;
671 
672 	reg_offset = trx_len - 1;
673 	list_for_each_entry(t, &m->transfers, transfer_list) {
674 		rxbuf = t->rx_buf;
675 		for (i = 0; i < t->len; i++, reg_offset--) {
676 			reg = sp->base + MTK_NOR_REG_SHIFT(reg_offset);
677 			if (rxbuf)
678 				rxbuf[i] = readb(reg);
679 		}
680 	}
681 
682 	m->actual_length = trx_len;
683 msg_done:
684 	m->status = stat;
685 	spi_finalize_current_message(master);
686 
687 	return 0;
688 }
689 
690 static void mtk_nor_disable_clk(struct mtk_nor *sp)
691 {
692 	clk_disable_unprepare(sp->spi_clk);
693 	clk_disable_unprepare(sp->ctlr_clk);
694 	clk_disable_unprepare(sp->axi_clk);
695 	clk_disable_unprepare(sp->axi_s_clk);
696 }
697 
698 static int mtk_nor_enable_clk(struct mtk_nor *sp)
699 {
700 	int ret;
701 
702 	ret = clk_prepare_enable(sp->spi_clk);
703 	if (ret)
704 		return ret;
705 
706 	ret = clk_prepare_enable(sp->ctlr_clk);
707 	if (ret) {
708 		clk_disable_unprepare(sp->spi_clk);
709 		return ret;
710 	}
711 
712 	ret = clk_prepare_enable(sp->axi_clk);
713 	if (ret) {
714 		clk_disable_unprepare(sp->spi_clk);
715 		clk_disable_unprepare(sp->ctlr_clk);
716 		return ret;
717 	}
718 
719 	ret = clk_prepare_enable(sp->axi_s_clk);
720 	if (ret) {
721 		clk_disable_unprepare(sp->spi_clk);
722 		clk_disable_unprepare(sp->ctlr_clk);
723 		clk_disable_unprepare(sp->axi_clk);
724 		return ret;
725 	}
726 
727 	return 0;
728 }
729 
730 static void mtk_nor_init(struct mtk_nor *sp)
731 {
732 	writel(0, sp->base + MTK_NOR_REG_IRQ_EN);
733 	writel(MTK_NOR_IRQ_MASK, sp->base + MTK_NOR_REG_IRQ_STAT);
734 
735 	writel(MTK_NOR_ENABLE_SF_CMD, sp->base + MTK_NOR_REG_WP);
736 	mtk_nor_rmw(sp, MTK_NOR_REG_CFG2, MTK_NOR_WR_CUSTOM_OP_EN, 0);
737 	mtk_nor_rmw(sp, MTK_NOR_REG_CFG3,
738 		    MTK_NOR_DISABLE_WREN | MTK_NOR_DISABLE_SR_POLL, 0);
739 }
740 
741 static irqreturn_t mtk_nor_irq_handler(int irq, void *data)
742 {
743 	struct mtk_nor *sp = data;
744 	u32 irq_status, irq_enabled;
745 
746 	irq_status = readl(sp->base + MTK_NOR_REG_IRQ_STAT);
747 	irq_enabled = readl(sp->base + MTK_NOR_REG_IRQ_EN);
748 	// write status back to clear interrupt
749 	writel(irq_status, sp->base + MTK_NOR_REG_IRQ_STAT);
750 
751 	if (!(irq_status & irq_enabled))
752 		return IRQ_NONE;
753 
754 	if (irq_status & MTK_NOR_IRQ_DMA) {
755 		complete(&sp->op_done);
756 		writel(0, sp->base + MTK_NOR_REG_IRQ_EN);
757 	}
758 
759 	return IRQ_HANDLED;
760 }
761 
762 static size_t mtk_max_msg_size(struct spi_device *spi)
763 {
764 	return MTK_NOR_PRG_MAX_SIZE;
765 }
766 
767 static const struct spi_controller_mem_ops mtk_nor_mem_ops = {
768 	.adjust_op_size = mtk_nor_adjust_op_size,
769 	.supports_op = mtk_nor_supports_op,
770 	.exec_op = mtk_nor_exec_op
771 };
772 
773 static const struct mtk_nor_caps mtk_nor_caps_mt8173 = {
774 	.dma_bits = 32,
775 	.extra_dummy_bit = 0,
776 };
777 
778 static const struct mtk_nor_caps mtk_nor_caps_mt8186 = {
779 	.dma_bits = 32,
780 	.extra_dummy_bit = 1,
781 };
782 
783 static const struct mtk_nor_caps mtk_nor_caps_mt8192 = {
784 	.dma_bits = 36,
785 	.extra_dummy_bit = 0,
786 };
787 
788 static const struct of_device_id mtk_nor_match[] = {
789 	{ .compatible = "mediatek,mt8173-nor", .data = &mtk_nor_caps_mt8173 },
790 	{ .compatible = "mediatek,mt8186-nor", .data = &mtk_nor_caps_mt8186 },
791 	{ .compatible = "mediatek,mt8192-nor", .data = &mtk_nor_caps_mt8192 },
792 	{ /* sentinel */ }
793 };
794 MODULE_DEVICE_TABLE(of, mtk_nor_match);
795 
796 static int mtk_nor_probe(struct platform_device *pdev)
797 {
798 	struct spi_controller *ctlr;
799 	struct mtk_nor *sp;
800 	struct mtk_nor_caps *caps;
801 	void __iomem *base;
802 	struct clk *spi_clk, *ctlr_clk, *axi_clk, *axi_s_clk;
803 	int ret, irq;
804 
805 	base = devm_platform_ioremap_resource(pdev, 0);
806 	if (IS_ERR(base))
807 		return PTR_ERR(base);
808 
809 	spi_clk = devm_clk_get(&pdev->dev, "spi");
810 	if (IS_ERR(spi_clk))
811 		return PTR_ERR(spi_clk);
812 
813 	ctlr_clk = devm_clk_get(&pdev->dev, "sf");
814 	if (IS_ERR(ctlr_clk))
815 		return PTR_ERR(ctlr_clk);
816 
817 	axi_clk = devm_clk_get_optional(&pdev->dev, "axi");
818 	if (IS_ERR(axi_clk))
819 		return PTR_ERR(axi_clk);
820 
821 	axi_s_clk = devm_clk_get_optional(&pdev->dev, "axi_s");
822 	if (IS_ERR(axi_s_clk))
823 		return PTR_ERR(axi_s_clk);
824 
825 	caps = (struct mtk_nor_caps *)of_device_get_match_data(&pdev->dev);
826 
827 	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(caps->dma_bits));
828 	if (ret) {
829 		dev_err(&pdev->dev, "failed to set dma mask(%u)\n", caps->dma_bits);
830 		return ret;
831 	}
832 
833 	ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*sp));
834 	if (!ctlr) {
835 		dev_err(&pdev->dev, "failed to allocate spi controller\n");
836 		return -ENOMEM;
837 	}
838 
839 	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
840 	ctlr->dev.of_node = pdev->dev.of_node;
841 	ctlr->max_message_size = mtk_max_msg_size;
842 	ctlr->mem_ops = &mtk_nor_mem_ops;
843 	ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD | SPI_TX_DUAL | SPI_TX_QUAD;
844 	ctlr->num_chipselect = 1;
845 	ctlr->setup = mtk_nor_setup;
846 	ctlr->transfer_one_message = mtk_nor_transfer_one_message;
847 	ctlr->auto_runtime_pm = true;
848 
849 	dev_set_drvdata(&pdev->dev, ctlr);
850 
851 	sp = spi_controller_get_devdata(ctlr);
852 	sp->base = base;
853 	sp->has_irq = false;
854 	sp->wbuf_en = false;
855 	sp->ctlr = ctlr;
856 	sp->dev = &pdev->dev;
857 	sp->spi_clk = spi_clk;
858 	sp->ctlr_clk = ctlr_clk;
859 	sp->axi_clk = axi_clk;
860 	sp->axi_s_clk = axi_s_clk;
861 	sp->caps = caps;
862 	sp->high_dma = caps->dma_bits > 32;
863 	sp->buffer = dmam_alloc_coherent(&pdev->dev,
864 				MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN,
865 				&sp->buffer_dma, GFP_KERNEL);
866 	if (!sp->buffer)
867 		return -ENOMEM;
868 
869 	if ((uintptr_t)sp->buffer & MTK_NOR_DMA_ALIGN_MASK) {
870 		dev_err(sp->dev, "misaligned allocation of internal buffer.\n");
871 		return -ENOMEM;
872 	}
873 
874 	ret = mtk_nor_enable_clk(sp);
875 	if (ret < 0)
876 		return ret;
877 
878 	sp->spi_freq = clk_get_rate(sp->spi_clk);
879 
880 	mtk_nor_init(sp);
881 
882 	irq = platform_get_irq_optional(pdev, 0);
883 
884 	if (irq < 0) {
885 		dev_warn(sp->dev, "IRQ not available.");
886 	} else {
887 		ret = devm_request_irq(sp->dev, irq, mtk_nor_irq_handler, 0,
888 				       pdev->name, sp);
889 		if (ret < 0) {
890 			dev_warn(sp->dev, "failed to request IRQ.");
891 		} else {
892 			init_completion(&sp->op_done);
893 			sp->has_irq = true;
894 		}
895 	}
896 
897 	pm_runtime_set_autosuspend_delay(&pdev->dev, -1);
898 	pm_runtime_use_autosuspend(&pdev->dev);
899 	pm_runtime_set_active(&pdev->dev);
900 	pm_runtime_enable(&pdev->dev);
901 	pm_runtime_get_noresume(&pdev->dev);
902 
903 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
904 	if (ret < 0)
905 		goto err_probe;
906 
907 	pm_runtime_mark_last_busy(&pdev->dev);
908 	pm_runtime_put_autosuspend(&pdev->dev);
909 
910 	dev_info(&pdev->dev, "spi frequency: %d Hz\n", sp->spi_freq);
911 
912 	return 0;
913 
914 err_probe:
915 	pm_runtime_disable(&pdev->dev);
916 	pm_runtime_set_suspended(&pdev->dev);
917 	pm_runtime_dont_use_autosuspend(&pdev->dev);
918 
919 	mtk_nor_disable_clk(sp);
920 
921 	return ret;
922 }
923 
924 static int mtk_nor_remove(struct platform_device *pdev)
925 {
926 	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
927 	struct mtk_nor *sp = spi_controller_get_devdata(ctlr);
928 
929 	pm_runtime_disable(&pdev->dev);
930 	pm_runtime_set_suspended(&pdev->dev);
931 	pm_runtime_dont_use_autosuspend(&pdev->dev);
932 
933 	mtk_nor_disable_clk(sp);
934 
935 	return 0;
936 }
937 
938 static int __maybe_unused mtk_nor_runtime_suspend(struct device *dev)
939 {
940 	struct spi_controller *ctlr = dev_get_drvdata(dev);
941 	struct mtk_nor *sp = spi_controller_get_devdata(ctlr);
942 
943 	mtk_nor_disable_clk(sp);
944 
945 	return 0;
946 }
947 
948 static int __maybe_unused mtk_nor_runtime_resume(struct device *dev)
949 {
950 	struct spi_controller *ctlr = dev_get_drvdata(dev);
951 	struct mtk_nor *sp = spi_controller_get_devdata(ctlr);
952 
953 	return mtk_nor_enable_clk(sp);
954 }
955 
956 static int __maybe_unused mtk_nor_suspend(struct device *dev)
957 {
958 	return pm_runtime_force_suspend(dev);
959 }
960 
961 static int __maybe_unused mtk_nor_resume(struct device *dev)
962 {
963 	struct spi_controller *ctlr = dev_get_drvdata(dev);
964 	struct mtk_nor *sp = spi_controller_get_devdata(ctlr);
965 	int ret;
966 
967 	ret = pm_runtime_force_resume(dev);
968 	if (ret)
969 		return ret;
970 
971 	mtk_nor_init(sp);
972 
973 	return 0;
974 }
975 
976 static const struct dev_pm_ops mtk_nor_pm_ops = {
977 	SET_RUNTIME_PM_OPS(mtk_nor_runtime_suspend,
978 			   mtk_nor_runtime_resume, NULL)
979 	SET_SYSTEM_SLEEP_PM_OPS(mtk_nor_suspend, mtk_nor_resume)
980 };
981 
982 static struct platform_driver mtk_nor_driver = {
983 	.driver = {
984 		.name = DRIVER_NAME,
985 		.of_match_table = mtk_nor_match,
986 		.pm = &mtk_nor_pm_ops,
987 	},
988 	.probe = mtk_nor_probe,
989 	.remove = mtk_nor_remove,
990 };
991 
992 module_platform_driver(mtk_nor_driver);
993 
994 MODULE_DESCRIPTION("Mediatek SPI NOR controller driver");
995 MODULE_AUTHOR("Chuanhong Guo <gch981213@gmail.com>");
996 MODULE_LICENSE("GPL v2");
997 MODULE_ALIAS("platform:" DRIVER_NAME);
998