1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Mediatek SPI-NOR controller driver
4 //
5 // Copyright (C) 2020 SkyLake Huang <SkyLake.Huang@mediatek.com>
6 //
7 // Some parts are based on drivers/spi/spi-mtk-nor.c of linux version
8 
9 #include <clk.h>
10 #include <common.h>
11 #include <cpu_func.h>
12 #include <dm.h>
13 #include <dm/device.h>
14 #include <dm/device_compat.h>
15 #include <dm/devres.h>
16 #include <dm/pinctrl.h>
17 #include <linux/bitops.h>
18 #include <linux/completion.h>
19 #include <linux/io.h>
20 #include <linux/iopoll.h>
21 #include <spi.h>
22 #include <spi-mem.h>
23 #include <stdbool.h>
24 #include <watchdog.h>
25 #include <linux/dma-mapping.h>
26 
27 #define DRIVER_NAME "mtk-spi-nor"
28 
29 #define MTK_NOR_REG_CMD 0x00
30 #define MTK_NOR_CMD_WRSR BIT(5)
31 #define MTK_NOR_CMD_WRITE BIT(4)
32 #define MTK_NOR_CMD_PROGRAM BIT(2)
33 #define MTK_NOR_CMD_RDSR BIT(1)
34 #define MTK_NOR_CMD_READ BIT(0)
35 #define MTK_NOR_CMD_MASK GENMASK(5, 0)
36 
37 #define MTK_NOR_REG_PRG_CNT 0x04
38 #define MTK_NOR_REG_RDSR 0x08
39 #define MTK_NOR_REG_RDATA 0x0c
40 
41 #define MTK_NOR_REG_RADR0 0x10
42 #define MTK_NOR_REG_RADR(n) (MTK_NOR_REG_RADR0 + 4 * (n))
43 #define MTK_NOR_REG_RADR3 0xc8
44 
45 #define MTK_NOR_REG_WDATA 0x1c
46 
47 #define MTK_NOR_REG_PRGDATA0 0x20
48 #define MTK_NOR_REG_PRGDATA(n) (MTK_NOR_REG_PRGDATA0 + 4 * (n))
49 #define MTK_NOR_REG_PRGDATA_MAX 5
50 
51 #define MTK_NOR_REG_SHIFT0 0x38
52 #define MTK_NOR_REG_SHIFT(n) (MTK_NOR_REG_SHIFT0 + 4 * (n))
53 #define MTK_NOR_REG_SHIFT_MAX 9
54 
55 #define MTK_NOR_REG_CFG1 0x60
56 #define MTK_NOR_FAST_READ BIT(0)
57 
58 #define MTK_NOR_REG_CFG2 0x64
59 #define MTK_NOR_WR_CUSTOM_OP_EN BIT(4)
60 #define MTK_NOR_WR_BUF_EN BIT(0)
61 
62 #define MTK_NOR_REG_PP_DATA 0x98
63 
64 #define MTK_NOR_REG_IRQ_STAT 0xa8
65 #define MTK_NOR_REG_IRQ_EN 0xac
66 #define MTK_NOR_IRQ_DMA BIT(7)
67 #define MTK_NOR_IRQ_WRSR BIT(5)
68 #define MTK_NOR_IRQ_MASK GENMASK(7, 0)
69 
70 #define MTK_NOR_REG_CFG3 0xb4
71 #define MTK_NOR_DISABLE_WREN BIT(7)
72 #define MTK_NOR_DISABLE_SR_POLL BIT(5)
73 
74 #define MTK_NOR_REG_WP 0xc4
75 #define MTK_NOR_ENABLE_SF_CMD 0x30
76 
77 #define MTK_NOR_REG_BUSCFG 0xcc
78 #define MTK_NOR_4B_ADDR BIT(4)
79 #define MTK_NOR_QUAD_ADDR BIT(3)
80 #define MTK_NOR_QUAD_READ BIT(2)
81 #define MTK_NOR_DUAL_ADDR BIT(1)
82 #define MTK_NOR_DUAL_READ BIT(0)
83 #define MTK_NOR_BUS_MODE_MASK GENMASK(4, 0)
84 
85 #define MTK_NOR_REG_DMA_CTL 0x718
86 #define MTK_NOR_DMA_START BIT(0)
87 
88 #define MTK_NOR_REG_DMA_FADR 0x71c
89 #define MTK_NOR_REG_DMA_DADR 0x720
90 #define MTK_NOR_REG_DMA_END_DADR 0x724
91 
92 #define MTK_NOR_PRG_MAX_SIZE 6
93 // Reading DMA src/dst addresses have to be 16-byte aligned
94 #define MTK_NOR_DMA_ALIGN 16
95 #define MTK_NOR_DMA_ALIGN_MASK (MTK_NOR_DMA_ALIGN - 1)
96 // and we allocate a bounce buffer if destination address isn't aligned.
97 #define MTK_NOR_BOUNCE_BUF_SIZE PAGE_SIZE
98 
99 // Buffered page program can do one 128-byte transfer
100 #define MTK_NOR_PP_SIZE 128
101 
102 #define CLK_TO_US(priv, clkcnt) DIV_ROUND_UP(clkcnt, (priv)->spi_freq / 1000000)
103 
104 #define MTK_NOR_UNLOCK_ALL 0x0
105 
106 struct mtk_snor_priv {
107 	struct device *dev;
108 	void __iomem *base;
109 	u8 *buffer;
110 	struct clk spi_clk;
111 	struct clk ctlr_clk;
112 	unsigned int spi_freq;
113 	bool wbuf_en;
114 };
115 
mtk_snor_rmw(struct mtk_snor_priv * priv,u32 reg,u32 set,u32 clr)116 static inline void mtk_snor_rmw(struct mtk_snor_priv *priv, u32 reg, u32 set,
117 				u32 clr)
118 {
119 	u32 val = readl(priv->base + reg);
120 
121 	val &= ~clr;
122 	val |= set;
123 	writel(val, priv->base + reg);
124 }
125 
mtk_snor_cmd_exec(struct mtk_snor_priv * priv,u32 cmd,ulong clk)126 static inline int mtk_snor_cmd_exec(struct mtk_snor_priv *priv, u32 cmd,
127 				    ulong clk)
128 {
129 	unsigned long long delay = CLK_TO_US(priv, clk);
130 	u32 reg;
131 	int ret;
132 
133 	writel(cmd, priv->base + MTK_NOR_REG_CMD);
134 	delay = (delay + 1) * 200;
135 	ret = readl_poll_timeout(priv->base + MTK_NOR_REG_CMD, reg,
136 				 !(reg & cmd), delay);
137 	if (ret < 0)
138 		dev_err(priv->dev, "command %u timeout.\n", cmd);
139 	return ret;
140 }
141 
mtk_snor_set_addr(struct mtk_snor_priv * priv,const struct spi_mem_op * op)142 static void mtk_snor_set_addr(struct mtk_snor_priv *priv,
143 			      const struct spi_mem_op *op)
144 {
145 	u32 addr = op->addr.val;
146 	int i;
147 
148 	for (i = 0; i < 3; i++) {
149 		writeb(addr & 0xff, priv->base + MTK_NOR_REG_RADR(i));
150 		addr >>= 8;
151 	}
152 	if (op->addr.nbytes == 4) {
153 		writeb(addr & 0xff, priv->base + MTK_NOR_REG_RADR3);
154 		mtk_snor_rmw(priv, MTK_NOR_REG_BUSCFG, MTK_NOR_4B_ADDR, 0);
155 	} else {
156 		mtk_snor_rmw(priv, MTK_NOR_REG_BUSCFG, 0, MTK_NOR_4B_ADDR);
157 	}
158 }
159 
need_bounce(const struct spi_mem_op * op)160 static bool need_bounce(const struct spi_mem_op *op)
161 {
162 	return ((uintptr_t)op->data.buf.in & MTK_NOR_DMA_ALIGN_MASK);
163 }
164 
mtk_snor_adjust_op_size(struct spi_slave * slave,struct spi_mem_op * op)165 static int mtk_snor_adjust_op_size(struct spi_slave *slave,
166 				   struct spi_mem_op *op)
167 {
168 	if (!op->data.nbytes)
169 		return 0;
170 
171 	if (op->addr.nbytes == 3 || op->addr.nbytes == 4) {
172 		if (op->data.dir == SPI_MEM_DATA_IN) { //&&
173 			// limit size to prevent timeout calculation overflow
174 			if (op->data.nbytes > 0x400000)
175 				op->data.nbytes = 0x400000;
176 			if (op->addr.val & MTK_NOR_DMA_ALIGN_MASK ||
177 			    op->data.nbytes < MTK_NOR_DMA_ALIGN)
178 				op->data.nbytes = 1;
179 			else if (!need_bounce(op))
180 				op->data.nbytes &= ~MTK_NOR_DMA_ALIGN_MASK;
181 			else if (op->data.nbytes > MTK_NOR_BOUNCE_BUF_SIZE)
182 				op->data.nbytes = MTK_NOR_BOUNCE_BUF_SIZE;
183 			return 0;
184 		} else if (op->data.dir == SPI_MEM_DATA_OUT) {
185 			if (op->data.nbytes >= MTK_NOR_PP_SIZE)
186 				op->data.nbytes = MTK_NOR_PP_SIZE;
187 			else
188 				op->data.nbytes = 1;
189 			return 0;
190 		}
191 	}
192 
193 	return 0;
194 }
195 
mtk_snor_supports_op(struct spi_slave * slave,const struct spi_mem_op * op)196 static bool mtk_snor_supports_op(struct spi_slave *slave,
197 				 const struct spi_mem_op *op)
198 {
199 	/* This controller only supports 1-1-1 write mode */
200 	if (op->data.dir == SPI_MEM_DATA_OUT &&
201 	    (op->cmd.buswidth != 1 || op->data.buswidth != 1))
202 		return false;
203 
204 	return true;
205 }
206 
mtk_snor_setup_bus(struct mtk_snor_priv * priv,const struct spi_mem_op * op)207 static void mtk_snor_setup_bus(struct mtk_snor_priv *priv,
208 			       const struct spi_mem_op *op)
209 {
210 	u32 reg = 0;
211 
212 	if (op->addr.nbytes == 4)
213 		reg |= MTK_NOR_4B_ADDR;
214 
215 	if (op->data.buswidth == 4) {
216 		reg |= MTK_NOR_QUAD_READ;
217 		writeb(op->cmd.opcode, priv->base + MTK_NOR_REG_PRGDATA(4));
218 		if (op->addr.buswidth == 4)
219 			reg |= MTK_NOR_QUAD_ADDR;
220 	} else if (op->data.buswidth == 2) {
221 		reg |= MTK_NOR_DUAL_READ;
222 		writeb(op->cmd.opcode, priv->base + MTK_NOR_REG_PRGDATA(3));
223 		if (op->addr.buswidth == 2)
224 			reg |= MTK_NOR_DUAL_ADDR;
225 	} else {
226 		if (op->cmd.opcode == 0x0b)
227 			mtk_snor_rmw(priv, MTK_NOR_REG_CFG1, MTK_NOR_FAST_READ,
228 				     0);
229 		else
230 			mtk_snor_rmw(priv, MTK_NOR_REG_CFG1, 0,
231 				     MTK_NOR_FAST_READ);
232 	}
233 	mtk_snor_rmw(priv, MTK_NOR_REG_BUSCFG, reg, MTK_NOR_BUS_MODE_MASK);
234 }
235 
mtk_snor_dma_exec(struct mtk_snor_priv * priv,u32 from,unsigned int length,dma_addr_t dma_addr)236 static int mtk_snor_dma_exec(struct mtk_snor_priv *priv, u32 from,
237 			     unsigned int length, dma_addr_t dma_addr)
238 {
239 	int ret = 0;
240 	ulong delay;
241 	u32 reg;
242 
243 	writel(from, priv->base + MTK_NOR_REG_DMA_FADR);
244 	writel(dma_addr, priv->base + MTK_NOR_REG_DMA_DADR);
245 	writel(dma_addr + length, priv->base + MTK_NOR_REG_DMA_END_DADR);
246 
247 	mtk_snor_rmw(priv, MTK_NOR_REG_DMA_CTL, MTK_NOR_DMA_START, 0);
248 
249 	delay = CLK_TO_US(priv, (length + 5) * BITS_PER_BYTE);
250 
251 	delay = (delay + 1) * 100;
252 	ret = readl_poll_timeout(priv->base + MTK_NOR_REG_DMA_CTL, reg,
253 				 !(reg & MTK_NOR_DMA_START), delay);
254 
255 	if (ret < 0)
256 		dev_err(priv->dev, "dma read timeout.\n");
257 
258 	return ret;
259 }
260 
mtk_snor_read_bounce(struct mtk_snor_priv * priv,const struct spi_mem_op * op)261 static int mtk_snor_read_bounce(struct mtk_snor_priv *priv,
262 				const struct spi_mem_op *op)
263 {
264 	unsigned int rdlen;
265 	int ret;
266 
267 	if (op->data.nbytes & MTK_NOR_DMA_ALIGN_MASK)
268 		rdlen = (op->data.nbytes + MTK_NOR_DMA_ALIGN) &
269 			~MTK_NOR_DMA_ALIGN_MASK;
270 	else
271 		rdlen = op->data.nbytes;
272 
273 	ret = mtk_snor_dma_exec(priv, op->addr.val, rdlen,
274 				(dma_addr_t)priv->buffer);
275 
276 	if (!ret)
277 		memcpy(op->data.buf.in, priv->buffer, op->data.nbytes);
278 
279 	return ret;
280 }
281 
mtk_snor_read_dma(struct mtk_snor_priv * priv,const struct spi_mem_op * op)282 static int mtk_snor_read_dma(struct mtk_snor_priv *priv,
283 			     const struct spi_mem_op *op)
284 {
285 	int ret;
286 	dma_addr_t dma_addr;
287 
288 	if (need_bounce(op))
289 		return mtk_snor_read_bounce(priv, op);
290 
291 	dma_addr = dma_map_single(op->data.buf.in, op->data.nbytes,
292 				  DMA_FROM_DEVICE);
293 
294 	if (dma_mapping_error(priv->dev, dma_addr))
295 		return -EINVAL;
296 
297 	ret = mtk_snor_dma_exec(priv, op->addr.val, op->data.nbytes, dma_addr);
298 
299 	dma_unmap_single(dma_addr, op->data.nbytes, DMA_FROM_DEVICE);
300 
301 	return ret;
302 }
303 
mtk_snor_read_pio(struct mtk_snor_priv * priv,const struct spi_mem_op * op)304 static int mtk_snor_read_pio(struct mtk_snor_priv *priv,
305 			     const struct spi_mem_op *op)
306 {
307 	u8 *buf = op->data.buf.in;
308 	int ret;
309 
310 	ret = mtk_snor_cmd_exec(priv, MTK_NOR_CMD_READ, 6 * BITS_PER_BYTE);
311 	if (!ret)
312 		buf[0] = readb(priv->base + MTK_NOR_REG_RDATA);
313 	return ret;
314 }
315 
mtk_snor_write_buffer_enable(struct mtk_snor_priv * priv)316 static int mtk_snor_write_buffer_enable(struct mtk_snor_priv *priv)
317 {
318 	int ret;
319 	u32 val;
320 
321 	if (priv->wbuf_en)
322 		return 0;
323 
324 	val = readl(priv->base + MTK_NOR_REG_CFG2);
325 	writel(val | MTK_NOR_WR_BUF_EN, priv->base + MTK_NOR_REG_CFG2);
326 	ret = readl_poll_timeout(priv->base + MTK_NOR_REG_CFG2, val,
327 				 val & MTK_NOR_WR_BUF_EN, 10000);
328 	if (!ret)
329 		priv->wbuf_en = true;
330 	return ret;
331 }
332 
mtk_snor_write_buffer_disable(struct mtk_snor_priv * priv)333 static int mtk_snor_write_buffer_disable(struct mtk_snor_priv *priv)
334 {
335 	int ret;
336 	u32 val;
337 
338 	if (!priv->wbuf_en)
339 		return 0;
340 	val = readl(priv->base + MTK_NOR_REG_CFG2);
341 	writel(val & ~MTK_NOR_WR_BUF_EN, priv->base + MTK_NOR_REG_CFG2);
342 	ret = readl_poll_timeout(priv->base + MTK_NOR_REG_CFG2, val,
343 				 !(val & MTK_NOR_WR_BUF_EN), 10000);
344 	if (!ret)
345 		priv->wbuf_en = false;
346 	return ret;
347 }
348 
mtk_snor_pp_buffered(struct mtk_snor_priv * priv,const struct spi_mem_op * op)349 static int mtk_snor_pp_buffered(struct mtk_snor_priv *priv,
350 				const struct spi_mem_op *op)
351 {
352 	const u8 *buf = op->data.buf.out;
353 	u32 val;
354 	int ret, i;
355 
356 	ret = mtk_snor_write_buffer_enable(priv);
357 	if (ret < 0)
358 		return ret;
359 
360 	for (i = 0; i < op->data.nbytes; i += 4) {
361 		val = buf[i + 3] << 24 | buf[i + 2] << 16 | buf[i + 1] << 8 |
362 		      buf[i];
363 		writel(val, priv->base + MTK_NOR_REG_PP_DATA);
364 	}
365 	mtk_snor_cmd_exec(priv, MTK_NOR_CMD_WRITE,
366 			  (op->data.nbytes + 5) * BITS_PER_BYTE);
367 	return mtk_snor_write_buffer_disable(priv);
368 }
369 
mtk_snor_pp_unbuffered(struct mtk_snor_priv * priv,const struct spi_mem_op * op)370 static int mtk_snor_pp_unbuffered(struct mtk_snor_priv *priv,
371 				  const struct spi_mem_op *op)
372 {
373 	const u8 *buf = op->data.buf.out;
374 	int ret;
375 
376 	ret = mtk_snor_write_buffer_disable(priv);
377 	if (ret < 0)
378 		return ret;
379 	writeb(buf[0], priv->base + MTK_NOR_REG_WDATA);
380 	return mtk_snor_cmd_exec(priv, MTK_NOR_CMD_WRITE, 6 * BITS_PER_BYTE);
381 }
382 
mtk_snor_cmd_program(struct mtk_snor_priv * priv,const struct spi_mem_op * op)383 static int mtk_snor_cmd_program(struct mtk_snor_priv *priv,
384 				const struct spi_mem_op *op)
385 {
386 	u32 tx_len = 0;
387 	u32 trx_len = 0;
388 	int reg_offset = MTK_NOR_REG_PRGDATA_MAX;
389 	void __iomem *reg;
390 	u8 *txbuf;
391 	int tx_cnt = 0;
392 	u8 *rxbuf = op->data.buf.in;
393 	int i = 0;
394 
395 	tx_len = 1 + op->addr.nbytes + op->dummy.nbytes;
396 	trx_len = tx_len + op->data.nbytes;
397 	if (op->data.dir == SPI_MEM_DATA_OUT)
398 		tx_len += op->data.nbytes;
399 
400 	txbuf = kmalloc_array(tx_len, sizeof(u8), GFP_KERNEL);
401 	memset(txbuf, 0x0, tx_len * sizeof(u8));
402 
403 	/* Join all bytes to be transferred */
404 	txbuf[tx_cnt] = op->cmd.opcode;
405 	tx_cnt++;
406 	for (i = op->addr.nbytes; i > 0; i--, tx_cnt++)
407 		txbuf[tx_cnt] = ((u8 *)&op->addr.val)[i - 1];
408 	for (i = op->dummy.nbytes; i > 0; i--, tx_cnt++)
409 		txbuf[tx_cnt] = 0x0;
410 	if (op->data.dir == SPI_MEM_DATA_OUT)
411 		for (i = op->data.nbytes; i > 0; i--, tx_cnt++)
412 			txbuf[tx_cnt] = ((u8 *)op->data.buf.out)[i - 1];
413 
414 	for (i = MTK_NOR_REG_PRGDATA_MAX; i >= 0; i--)
415 		writeb(0, priv->base + MTK_NOR_REG_PRGDATA(i));
416 
417 	for (i = 0; i < tx_len; i++, reg_offset--)
418 		writeb(txbuf[i], priv->base + MTK_NOR_REG_PRGDATA(reg_offset));
419 
420 	kfree(txbuf);
421 
422 	writel(trx_len * BITS_PER_BYTE, priv->base + MTK_NOR_REG_PRG_CNT);
423 
424 	mtk_snor_cmd_exec(priv, MTK_NOR_CMD_PROGRAM, trx_len * BITS_PER_BYTE);
425 
426 	reg_offset = op->data.nbytes - 1;
427 	for (i = 0; i < op->data.nbytes; i++, reg_offset--) {
428 		reg = priv->base + MTK_NOR_REG_SHIFT(reg_offset);
429 		rxbuf[i] = readb(reg);
430 	}
431 
432 	return 0;
433 }
434 
mtk_snor_exec_op(struct spi_slave * slave,const struct spi_mem_op * op)435 static int mtk_snor_exec_op(struct spi_slave *slave,
436 			    const struct spi_mem_op *op)
437 {
438 	struct udevice *bus = dev_get_parent(slave->dev);
439 	struct mtk_snor_priv *priv = dev_get_priv(bus);
440 	int ret;
441 
442 	if (op->data.dir == SPI_MEM_NO_DATA || op->addr.nbytes == 0) {
443 		return mtk_snor_cmd_program(priv, op);
444 	} else if (op->data.dir == SPI_MEM_DATA_OUT) {
445 		mtk_snor_set_addr(priv, op);
446 		writeb(op->cmd.opcode, priv->base + MTK_NOR_REG_PRGDATA0);
447 		if (op->data.nbytes == MTK_NOR_PP_SIZE)
448 			return mtk_snor_pp_buffered(priv, op);
449 		return mtk_snor_pp_unbuffered(priv, op);
450 	} else if (op->data.dir == SPI_MEM_DATA_IN) {
451 		ret = mtk_snor_write_buffer_disable(priv);
452 		if (ret < 0)
453 			return ret;
454 		mtk_snor_setup_bus(priv, op);
455 		if (op->data.nbytes == 1) {
456 			mtk_snor_set_addr(priv, op);
457 			return mtk_snor_read_pio(priv, op);
458 		} else {
459 			return mtk_snor_read_dma(priv, op);
460 		}
461 	}
462 
463 	return -ENOTSUPP;
464 }
465 
mtk_snor_probe(struct udevice * bus)466 static int mtk_snor_probe(struct udevice *bus)
467 {
468 	struct mtk_snor_priv *priv = dev_get_priv(bus);
469 	u8 *buffer;
470 	int ret;
471 	u32 reg;
472 
473 	priv->base = (void __iomem *)devfdt_get_addr(bus);
474 	if (!priv->base)
475 		return -EINVAL;
476 
477 	ret = clk_get_by_name(bus, "spi", &priv->spi_clk);
478 	if (ret < 0)
479 		return ret;
480 
481 	ret = clk_get_by_name(bus, "sf", &priv->ctlr_clk);
482 	if (ret < 0)
483 		return ret;
484 
485 	buffer = devm_kmalloc(bus, MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN,
486 			      GFP_KERNEL);
487 	if (!buffer)
488 		return -ENOMEM;
489 	if ((ulong)buffer & MTK_NOR_DMA_ALIGN_MASK)
490 		buffer = (u8 *)(((ulong)buffer + MTK_NOR_DMA_ALIGN) &
491 				~MTK_NOR_DMA_ALIGN_MASK);
492 	priv->buffer = buffer;
493 
494 	clk_enable(&priv->spi_clk);
495 	clk_enable(&priv->ctlr_clk);
496 
497 	priv->spi_freq = clk_get_rate(&priv->spi_clk);
498 	printf("spi frequency: %d Hz\n", priv->spi_freq);
499 
500 	/* With this setting, we issue one command at a time to
501 	 * accommodate to SPI-mem framework.
502 	 */
503 	writel(MTK_NOR_ENABLE_SF_CMD, priv->base + MTK_NOR_REG_WP);
504 	mtk_snor_rmw(priv, MTK_NOR_REG_CFG2, MTK_NOR_WR_CUSTOM_OP_EN, 0);
505 	mtk_snor_rmw(priv, MTK_NOR_REG_CFG3,
506 		     MTK_NOR_DISABLE_WREN | MTK_NOR_DISABLE_SR_POLL, 0);
507 
508 	/* Unlock all blocks using write status command.
509 	 * SPI-MEM hasn't implemented unlock procedure on MXIC devices.
510 	 * We may remove this later.
511 	 */
512 	writel(2 * BITS_PER_BYTE, priv->base + MTK_NOR_REG_PRG_CNT);
513 	writel(MTK_NOR_UNLOCK_ALL, priv->base + MTK_NOR_REG_PRGDATA(5));
514 	writel(MTK_NOR_IRQ_WRSR, priv->base + MTK_NOR_REG_IRQ_EN);
515 	writel(MTK_NOR_CMD_WRSR, priv->base + MTK_NOR_REG_CMD);
516 	ret = readl_poll_timeout(priv->base + MTK_NOR_REG_IRQ_STAT, reg,
517 				 !(reg & MTK_NOR_IRQ_WRSR),
518 				 ((3 * BITS_PER_BYTE) + 1) * 200);
519 
520 	return 0;
521 }
522 
mtk_snor_set_speed(struct udevice * bus,uint speed)523 static int mtk_snor_set_speed(struct udevice *bus, uint speed)
524 {
525 	/* MTK's SNOR controller does not have a bus clock divider.
526 	 * We setup maximum bus clock in dts.
527 	 */
528 
529 	return 0;
530 }
531 
mtk_snor_set_mode(struct udevice * bus,uint mode)532 static int mtk_snor_set_mode(struct udevice *bus, uint mode)
533 {
534 	/* We set up mode later for each transmission.
535 	 */
536 	return 0;
537 }
538 
539 static const struct spi_controller_mem_ops mtk_snor_mem_ops = {
540 	.adjust_op_size = mtk_snor_adjust_op_size,
541 	.supports_op = mtk_snor_supports_op,
542 	.exec_op = mtk_snor_exec_op
543 };
544 
545 static const struct dm_spi_ops mtk_snor_ops = {
546 	.mem_ops = &mtk_snor_mem_ops,
547 	.set_speed = mtk_snor_set_speed,
548 	.set_mode = mtk_snor_set_mode,
549 };
550 
551 static const struct udevice_id mtk_snor_ids[] = {
552 	{ .compatible = "mediatek,mtk-snor" },
553 	{}
554 };
555 
556 U_BOOT_DRIVER(mtk_snor) = {
557 	.name = "mtk_snor",
558 	.id = UCLASS_SPI,
559 	.of_match = mtk_snor_ids,
560 	.ops = &mtk_snor_ops,
561 	.priv_auto = sizeof(struct mtk_snor_priv),
562 	.probe = mtk_snor_probe,
563 };
564