1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2016
4  *
5  * Michael Kurz, <michi.kurz@gmail.com>
6  *
7  * STM32 QSPI driver
8  */
9 
10 #define LOG_CATEGORY UCLASS_SPI
11 
12 #include <common.h>
13 #include <clk.h>
14 #include <dm.h>
15 #include <log.h>
16 #include <reset.h>
17 #include <spi.h>
18 #include <spi-mem.h>
19 #include <watchdog.h>
20 #include <dm/device_compat.h>
21 #include <linux/bitops.h>
22 #include <linux/delay.h>
23 #include <linux/iopoll.h>
24 #include <linux/ioport.h>
25 #include <linux/sizes.h>
26 
27 struct stm32_qspi_regs {
28 	u32 cr;		/* 0x00 */
29 	u32 dcr;	/* 0x04 */
30 	u32 sr;		/* 0x08 */
31 	u32 fcr;	/* 0x0C */
32 	u32 dlr;	/* 0x10 */
33 	u32 ccr;	/* 0x14 */
34 	u32 ar;		/* 0x18 */
35 	u32 abr;	/* 0x1C */
36 	u32 dr;		/* 0x20 */
37 	u32 psmkr;	/* 0x24 */
38 	u32 psmar;	/* 0x28 */
39 	u32 pir;	/* 0x2C */
40 	u32 lptr;	/* 0x30 */
41 };
42 
43 /*
44  * QUADSPI control register
45  */
46 #define STM32_QSPI_CR_EN		BIT(0)
47 #define STM32_QSPI_CR_ABORT		BIT(1)
48 #define STM32_QSPI_CR_DMAEN		BIT(2)
49 #define STM32_QSPI_CR_TCEN		BIT(3)
50 #define STM32_QSPI_CR_SSHIFT		BIT(4)
51 #define STM32_QSPI_CR_DFM		BIT(6)
52 #define STM32_QSPI_CR_FSEL		BIT(7)
53 #define STM32_QSPI_CR_FTHRES_SHIFT	8
54 #define STM32_QSPI_CR_TEIE		BIT(16)
55 #define STM32_QSPI_CR_TCIE		BIT(17)
56 #define STM32_QSPI_CR_FTIE		BIT(18)
57 #define STM32_QSPI_CR_SMIE		BIT(19)
58 #define STM32_QSPI_CR_TOIE		BIT(20)
59 #define STM32_QSPI_CR_APMS		BIT(22)
60 #define STM32_QSPI_CR_PMM		BIT(23)
61 #define STM32_QSPI_CR_PRESCALER_MASK	GENMASK(7, 0)
62 #define STM32_QSPI_CR_PRESCALER_SHIFT	24
63 
64 /*
65  * QUADSPI device configuration register
66  */
67 #define STM32_QSPI_DCR_CKMODE		BIT(0)
68 #define STM32_QSPI_DCR_CSHT_MASK	GENMASK(2, 0)
69 #define STM32_QSPI_DCR_CSHT_SHIFT	8
70 #define STM32_QSPI_DCR_FSIZE_MASK	GENMASK(4, 0)
71 #define STM32_QSPI_DCR_FSIZE_SHIFT	16
72 
73 /*
74  * QUADSPI status register
75  */
76 #define STM32_QSPI_SR_TEF		BIT(0)
77 #define STM32_QSPI_SR_TCF		BIT(1)
78 #define STM32_QSPI_SR_FTF		BIT(2)
79 #define STM32_QSPI_SR_SMF		BIT(3)
80 #define STM32_QSPI_SR_TOF		BIT(4)
81 #define STM32_QSPI_SR_BUSY		BIT(5)
82 
83 /*
84  * QUADSPI flag clear register
85  */
86 #define STM32_QSPI_FCR_CTEF		BIT(0)
87 #define STM32_QSPI_FCR_CTCF		BIT(1)
88 #define STM32_QSPI_FCR_CSMF		BIT(3)
89 #define STM32_QSPI_FCR_CTOF		BIT(4)
90 
91 /*
92  * QUADSPI communication configuration register
93  */
94 #define STM32_QSPI_CCR_DDRM		BIT(31)
95 #define STM32_QSPI_CCR_DHHC		BIT(30)
96 #define STM32_QSPI_CCR_SIOO		BIT(28)
97 #define STM32_QSPI_CCR_FMODE_SHIFT	26
98 #define STM32_QSPI_CCR_DMODE_SHIFT	24
99 #define STM32_QSPI_CCR_DCYC_SHIFT	18
100 #define STM32_QSPI_CCR_ABSIZE_SHIFT	16
101 #define STM32_QSPI_CCR_ABMODE_SHIFT	14
102 #define STM32_QSPI_CCR_ADSIZE_SHIFT	12
103 #define STM32_QSPI_CCR_ADMODE_SHIFT	10
104 #define STM32_QSPI_CCR_IMODE_SHIFT	8
105 
106 #define STM32_QSPI_CCR_IND_WRITE	0
107 #define STM32_QSPI_CCR_IND_READ		1
108 #define STM32_QSPI_CCR_MEM_MAP		3
109 
110 #define STM32_QSPI_MAX_MMAP_SZ		SZ_256M
111 #define STM32_QSPI_MAX_CHIP		2
112 
113 #define STM32_QSPI_FIFO_TIMEOUT_US	30000
114 #define STM32_QSPI_CMD_TIMEOUT_US	1000000
115 #define STM32_BUSY_TIMEOUT_US		100000
116 #define STM32_ABT_TIMEOUT_US		100000
117 
118 struct stm32_qspi_flash {
119 	u32 cr;
120 	u32 dcr;
121 	bool initialized;
122 };
123 
124 struct stm32_qspi_priv {
125 	struct stm32_qspi_regs *regs;
126 	struct stm32_qspi_flash flash[STM32_QSPI_MAX_CHIP];
127 	void __iomem *mm_base;
128 	resource_size_t mm_size;
129 	ulong clock_rate;
130 	int cs_used;
131 };
132 
_stm32_qspi_wait_for_not_busy(struct stm32_qspi_priv * priv)133 static int _stm32_qspi_wait_for_not_busy(struct stm32_qspi_priv *priv)
134 {
135 	u32 sr;
136 	int ret;
137 
138 	ret = readl_poll_timeout(&priv->regs->sr, sr,
139 				 !(sr & STM32_QSPI_SR_BUSY),
140 				 STM32_BUSY_TIMEOUT_US);
141 	if (ret)
142 		log_err("busy timeout (stat:%#x)\n", sr);
143 
144 	return ret;
145 }
146 
_stm32_qspi_wait_cmd(struct stm32_qspi_priv * priv,const struct spi_mem_op * op)147 static int _stm32_qspi_wait_cmd(struct stm32_qspi_priv *priv,
148 				const struct spi_mem_op *op)
149 {
150 	u32 sr;
151 	int ret = 0;
152 
153 	if (op->data.nbytes) {
154 		ret = readl_poll_timeout(&priv->regs->sr, sr,
155 					 sr & STM32_QSPI_SR_TCF,
156 					 STM32_QSPI_CMD_TIMEOUT_US);
157 		if (ret) {
158 			log_err("cmd timeout (stat:%#x)\n", sr);
159 		} else if (readl(&priv->regs->sr) & STM32_QSPI_SR_TEF) {
160 			log_err("transfer error (stat:%#x)\n", sr);
161 			ret = -EIO;
162 		}
163 		/* clear flags */
164 		writel(STM32_QSPI_FCR_CTCF | STM32_QSPI_FCR_CTEF, &priv->regs->fcr);
165 	}
166 
167 	if (!ret)
168 		ret = _stm32_qspi_wait_for_not_busy(priv);
169 
170 	return ret;
171 }
172 
_stm32_qspi_read_fifo(u8 * val,void __iomem * addr)173 static void _stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
174 {
175 	*val = readb(addr);
176 	WATCHDOG_RESET();
177 }
178 
_stm32_qspi_write_fifo(u8 * val,void __iomem * addr)179 static void _stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
180 {
181 	writeb(*val, addr);
182 }
183 
_stm32_qspi_poll(struct stm32_qspi_priv * priv,const struct spi_mem_op * op)184 static int _stm32_qspi_poll(struct stm32_qspi_priv *priv,
185 			    const struct spi_mem_op *op)
186 {
187 	void (*fifo)(u8 *val, void __iomem *addr);
188 	u32 len = op->data.nbytes, sr;
189 	u8 *buf;
190 	int ret;
191 
192 	if (op->data.dir == SPI_MEM_DATA_IN) {
193 		fifo = _stm32_qspi_read_fifo;
194 		buf = op->data.buf.in;
195 
196 	} else {
197 		fifo = _stm32_qspi_write_fifo;
198 		buf = (u8 *)op->data.buf.out;
199 	}
200 
201 	while (len--) {
202 		ret = readl_poll_timeout(&priv->regs->sr, sr,
203 					 sr & STM32_QSPI_SR_FTF,
204 					 STM32_QSPI_FIFO_TIMEOUT_US);
205 		if (ret) {
206 			log_err("fifo timeout (len:%d stat:%#x)\n", len, sr);
207 			return ret;
208 		}
209 
210 		fifo(buf++, &priv->regs->dr);
211 	}
212 
213 	return 0;
214 }
215 
stm32_qspi_mm(struct stm32_qspi_priv * priv,const struct spi_mem_op * op)216 static int stm32_qspi_mm(struct stm32_qspi_priv *priv,
217 			 const struct spi_mem_op *op)
218 {
219 	memcpy_fromio(op->data.buf.in, priv->mm_base + op->addr.val,
220 		      op->data.nbytes);
221 
222 	return 0;
223 }
224 
_stm32_qspi_tx(struct stm32_qspi_priv * priv,const struct spi_mem_op * op,u8 mode)225 static int _stm32_qspi_tx(struct stm32_qspi_priv *priv,
226 			  const struct spi_mem_op *op,
227 			  u8 mode)
228 {
229 	if (!op->data.nbytes)
230 		return 0;
231 
232 	if (mode == STM32_QSPI_CCR_MEM_MAP)
233 		return stm32_qspi_mm(priv, op);
234 
235 	return _stm32_qspi_poll(priv, op);
236 }
237 
_stm32_qspi_get_mode(u8 buswidth)238 static int _stm32_qspi_get_mode(u8 buswidth)
239 {
240 	if (buswidth == 4)
241 		return 3;
242 
243 	return buswidth;
244 }
245 
stm32_qspi_exec_op(struct spi_slave * slave,const struct spi_mem_op * op)246 static int stm32_qspi_exec_op(struct spi_slave *slave,
247 			      const struct spi_mem_op *op)
248 {
249 	struct stm32_qspi_priv *priv = dev_get_priv(slave->dev->parent);
250 	u32 cr, ccr, addr_max;
251 	u8 mode = STM32_QSPI_CCR_IND_WRITE;
252 	int timeout, ret;
253 
254 	dev_dbg(slave->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n",
255 		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
256 		op->dummy.buswidth, op->data.buswidth,
257 		op->addr.val, op->data.nbytes);
258 
259 	ret = _stm32_qspi_wait_for_not_busy(priv);
260 	if (ret)
261 		return ret;
262 
263 	addr_max = op->addr.val + op->data.nbytes + 1;
264 
265 	if (op->data.dir == SPI_MEM_DATA_IN && op->data.nbytes) {
266 		if (addr_max < priv->mm_size && op->addr.buswidth)
267 			mode = STM32_QSPI_CCR_MEM_MAP;
268 		else
269 			mode = STM32_QSPI_CCR_IND_READ;
270 	}
271 
272 	if (op->data.nbytes)
273 		writel(op->data.nbytes - 1, &priv->regs->dlr);
274 
275 	ccr = (mode << STM32_QSPI_CCR_FMODE_SHIFT);
276 	ccr |= op->cmd.opcode;
277 	ccr |= (_stm32_qspi_get_mode(op->cmd.buswidth)
278 		<< STM32_QSPI_CCR_IMODE_SHIFT);
279 
280 	if (op->addr.nbytes) {
281 		ccr |= ((op->addr.nbytes - 1) << STM32_QSPI_CCR_ADSIZE_SHIFT);
282 		ccr |= (_stm32_qspi_get_mode(op->addr.buswidth)
283 			<< STM32_QSPI_CCR_ADMODE_SHIFT);
284 	}
285 
286 	if (op->dummy.buswidth && op->dummy.nbytes)
287 		ccr |= (op->dummy.nbytes * 8 / op->dummy.buswidth
288 			<< STM32_QSPI_CCR_DCYC_SHIFT);
289 
290 	if (op->data.nbytes)
291 		ccr |= (_stm32_qspi_get_mode(op->data.buswidth)
292 			<< STM32_QSPI_CCR_DMODE_SHIFT);
293 
294 	writel(ccr, &priv->regs->ccr);
295 
296 	if (op->addr.nbytes && mode != STM32_QSPI_CCR_MEM_MAP)
297 		writel(op->addr.val, &priv->regs->ar);
298 
299 	ret = _stm32_qspi_tx(priv, op, mode);
300 	/*
301 	 * Abort in:
302 	 * -error case
303 	 * -read memory map: prefetching must be stopped if we read the last
304 	 *  byte of device (device size - fifo size). like device size is not
305 	 *  knows, the prefetching is always stop.
306 	 */
307 	if (ret || mode == STM32_QSPI_CCR_MEM_MAP)
308 		goto abort;
309 
310 	/* Wait end of tx in indirect mode */
311 	ret = _stm32_qspi_wait_cmd(priv, op);
312 	if (ret)
313 		goto abort;
314 
315 	return 0;
316 
317 abort:
318 	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_ABORT);
319 
320 	/* Wait clear of abort bit by hw */
321 	timeout = readl_poll_timeout(&priv->regs->cr, cr,
322 				     !(cr & STM32_QSPI_CR_ABORT),
323 				     STM32_ABT_TIMEOUT_US);
324 
325 	writel(STM32_QSPI_FCR_CTCF, &priv->regs->fcr);
326 
327 	if (ret || timeout)
328 		dev_err(slave->dev, "ret:%d abort timeout:%d\n", ret, timeout);
329 
330 	return ret;
331 }
332 
stm32_qspi_probe(struct udevice * bus)333 static int stm32_qspi_probe(struct udevice *bus)
334 {
335 	struct stm32_qspi_priv *priv = dev_get_priv(bus);
336 	struct resource res;
337 	struct clk clk;
338 	struct reset_ctl reset_ctl;
339 	int ret;
340 
341 	ret = dev_read_resource_byname(bus, "qspi", &res);
342 	if (ret) {
343 		dev_err(bus, "can't get regs base addresses(ret = %d)!\n", ret);
344 		return ret;
345 	}
346 
347 	priv->regs = (struct stm32_qspi_regs *)res.start;
348 
349 	ret = dev_read_resource_byname(bus, "qspi_mm", &res);
350 	if (ret) {
351 		dev_err(bus, "can't get mmap base address(ret = %d)!\n", ret);
352 		return ret;
353 	}
354 
355 	priv->mm_base = (void __iomem *)res.start;
356 
357 	priv->mm_size = resource_size(&res);
358 	if (priv->mm_size > STM32_QSPI_MAX_MMAP_SZ)
359 		return -EINVAL;
360 
361 	dev_dbg(bus, "regs=<0x%p> mapped=<0x%p> mapped_size=<0x%lx>\n",
362 		priv->regs, priv->mm_base, priv->mm_size);
363 
364 	ret = clk_get_by_index(bus, 0, &clk);
365 	if (ret < 0)
366 		return ret;
367 
368 	ret = clk_enable(&clk);
369 	if (ret) {
370 		dev_err(bus, "failed to enable clock\n");
371 		return ret;
372 	}
373 
374 	priv->clock_rate = clk_get_rate(&clk);
375 	if (!priv->clock_rate) {
376 		clk_disable(&clk);
377 		return -EINVAL;
378 	}
379 
380 	ret = reset_get_by_index(bus, 0, &reset_ctl);
381 	if (ret) {
382 		if (ret != -ENOENT) {
383 			dev_err(bus, "failed to get reset\n");
384 			clk_disable(&clk);
385 			return ret;
386 		}
387 	} else {
388 		/* Reset QSPI controller */
389 		reset_assert(&reset_ctl);
390 		udelay(2);
391 		reset_deassert(&reset_ctl);
392 	}
393 
394 	priv->cs_used = -1;
395 
396 	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_SSHIFT);
397 
398 	/* Set dcr fsize to max address */
399 	setbits_le32(&priv->regs->dcr,
400 		     STM32_QSPI_DCR_FSIZE_MASK << STM32_QSPI_DCR_FSIZE_SHIFT);
401 
402 	return 0;
403 }
404 
stm32_qspi_claim_bus(struct udevice * dev)405 static int stm32_qspi_claim_bus(struct udevice *dev)
406 {
407 	struct stm32_qspi_priv *priv = dev_get_priv(dev->parent);
408 	struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
409 	int slave_cs = slave_plat->cs;
410 
411 	if (slave_cs >= STM32_QSPI_MAX_CHIP)
412 		return -ENODEV;
413 
414 	if (priv->cs_used != slave_cs) {
415 		struct stm32_qspi_flash *flash = &priv->flash[slave_cs];
416 
417 		priv->cs_used = slave_cs;
418 
419 		if (flash->initialized) {
420 			/* Set the configuration: speed + cs */
421 			writel(flash->cr, &priv->regs->cr);
422 			writel(flash->dcr, &priv->regs->dcr);
423 		} else {
424 			/* Set chip select */
425 			clrsetbits_le32(&priv->regs->cr, STM32_QSPI_CR_FSEL,
426 					priv->cs_used ? STM32_QSPI_CR_FSEL : 0);
427 
428 			/* Save the configuration: speed + cs */
429 			flash->cr = readl(&priv->regs->cr);
430 			flash->dcr = readl(&priv->regs->dcr);
431 
432 			flash->initialized = true;
433 		}
434 	}
435 
436 	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_EN);
437 
438 	return 0;
439 }
440 
stm32_qspi_release_bus(struct udevice * dev)441 static int stm32_qspi_release_bus(struct udevice *dev)
442 {
443 	struct stm32_qspi_priv *priv = dev_get_priv(dev->parent);
444 
445 	clrbits_le32(&priv->regs->cr, STM32_QSPI_CR_EN);
446 
447 	return 0;
448 }
449 
stm32_qspi_set_speed(struct udevice * bus,uint speed)450 static int stm32_qspi_set_speed(struct udevice *bus, uint speed)
451 {
452 	struct stm32_qspi_priv *priv = dev_get_priv(bus);
453 	u32 qspi_clk = priv->clock_rate;
454 	u32 prescaler = 255;
455 	u32 csht;
456 	int ret;
457 
458 	if (speed > 0) {
459 		prescaler = 0;
460 		if (qspi_clk) {
461 			prescaler = DIV_ROUND_UP(qspi_clk, speed) - 1;
462 			if (prescaler > 255)
463 				prescaler = 255;
464 		}
465 	}
466 
467 	csht = DIV_ROUND_UP((5 * qspi_clk) / (prescaler + 1), 100000000);
468 	csht = (csht - 1) & STM32_QSPI_DCR_CSHT_MASK;
469 
470 	ret = _stm32_qspi_wait_for_not_busy(priv);
471 	if (ret)
472 		return ret;
473 
474 	clrsetbits_le32(&priv->regs->cr,
475 			STM32_QSPI_CR_PRESCALER_MASK <<
476 			STM32_QSPI_CR_PRESCALER_SHIFT,
477 			prescaler << STM32_QSPI_CR_PRESCALER_SHIFT);
478 
479 	clrsetbits_le32(&priv->regs->dcr,
480 			STM32_QSPI_DCR_CSHT_MASK << STM32_QSPI_DCR_CSHT_SHIFT,
481 			csht << STM32_QSPI_DCR_CSHT_SHIFT);
482 
483 	dev_dbg(bus, "regs=%p, speed=%d\n", priv->regs,
484 		(qspi_clk / (prescaler + 1)));
485 
486 	return 0;
487 }
488 
stm32_qspi_set_mode(struct udevice * bus,uint mode)489 static int stm32_qspi_set_mode(struct udevice *bus, uint mode)
490 {
491 	struct stm32_qspi_priv *priv = dev_get_priv(bus);
492 	int ret;
493 	const char *str_rx, *str_tx;
494 
495 	ret = _stm32_qspi_wait_for_not_busy(priv);
496 	if (ret)
497 		return ret;
498 
499 	if ((mode & SPI_CPHA) && (mode & SPI_CPOL))
500 		setbits_le32(&priv->regs->dcr, STM32_QSPI_DCR_CKMODE);
501 	else if (!(mode & SPI_CPHA) && !(mode & SPI_CPOL))
502 		clrbits_le32(&priv->regs->dcr, STM32_QSPI_DCR_CKMODE);
503 	else
504 		return -ENODEV;
505 
506 	if (mode & SPI_CS_HIGH)
507 		return -ENODEV;
508 
509 	if (mode & SPI_RX_QUAD)
510 		str_rx = "quad";
511 	else if (mode & SPI_RX_DUAL)
512 		str_rx = "dual";
513 	else
514 		str_rx = "single";
515 
516 	if (mode & SPI_TX_QUAD)
517 		str_tx = "quad";
518 	else if (mode & SPI_TX_DUAL)
519 		str_tx = "dual";
520 	else
521 		str_tx = "single";
522 
523 	dev_dbg(bus, "regs=%p, mode=%d rx: %s, tx: %s\n",
524 		priv->regs, mode, str_rx, str_tx);
525 
526 	return 0;
527 }
528 
529 static const struct spi_controller_mem_ops stm32_qspi_mem_ops = {
530 	.exec_op = stm32_qspi_exec_op,
531 };
532 
533 static const struct dm_spi_ops stm32_qspi_ops = {
534 	.claim_bus	= stm32_qspi_claim_bus,
535 	.release_bus	= stm32_qspi_release_bus,
536 	.set_speed	= stm32_qspi_set_speed,
537 	.set_mode	= stm32_qspi_set_mode,
538 	.mem_ops	= &stm32_qspi_mem_ops,
539 };
540 
541 static const struct udevice_id stm32_qspi_ids[] = {
542 	{ .compatible = "st,stm32f469-qspi" },
543 	{ }
544 };
545 
546 U_BOOT_DRIVER(stm32_qspi) = {
547 	.name = "stm32_qspi",
548 	.id = UCLASS_SPI,
549 	.of_match = stm32_qspi_ids,
550 	.ops = &stm32_qspi_ops,
551 	.priv_auto	= sizeof(struct stm32_qspi_priv),
552 	.probe = stm32_qspi_probe,
553 };
554