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_priv {
119 	struct stm32_qspi_regs *regs;
120 	void __iomem *mm_base;
121 	resource_size_t mm_size;
122 	ulong clock_rate;
123 	int cs_used;
124 };
125 
_stm32_qspi_wait_for_not_busy(struct stm32_qspi_priv * priv)126 static int _stm32_qspi_wait_for_not_busy(struct stm32_qspi_priv *priv)
127 {
128 	u32 sr;
129 	int ret;
130 
131 	ret = readl_poll_timeout(&priv->regs->sr, sr,
132 				 !(sr & STM32_QSPI_SR_BUSY),
133 				 STM32_BUSY_TIMEOUT_US);
134 	if (ret)
135 		log_err("busy timeout (stat:%#x)\n", sr);
136 
137 	return ret;
138 }
139 
_stm32_qspi_wait_cmd(struct stm32_qspi_priv * priv,const struct spi_mem_op * op)140 static int _stm32_qspi_wait_cmd(struct stm32_qspi_priv *priv,
141 				const struct spi_mem_op *op)
142 {
143 	u32 sr;
144 	int ret = 0;
145 
146 	ret = readl_poll_timeout(&priv->regs->sr, sr,
147 				 sr & STM32_QSPI_SR_TCF,
148 				 STM32_QSPI_CMD_TIMEOUT_US);
149 	if (ret) {
150 		log_err("cmd timeout (stat:%#x)\n", sr);
151 	} else if (readl(&priv->regs->sr) & STM32_QSPI_SR_TEF) {
152 		log_err("transfer error (stat:%#x)\n", sr);
153 		ret = -EIO;
154 	}
155 
156 	/* clear flags */
157 	writel(STM32_QSPI_FCR_CTCF | STM32_QSPI_FCR_CTEF, &priv->regs->fcr);
158 
159 	if (!ret)
160 		ret = _stm32_qspi_wait_for_not_busy(priv);
161 
162 	return ret;
163 }
164 
_stm32_qspi_read_fifo(u8 * val,void __iomem * addr)165 static void _stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
166 {
167 	*val = readb(addr);
168 	schedule();
169 }
170 
_stm32_qspi_write_fifo(u8 * val,void __iomem * addr)171 static void _stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
172 {
173 	writeb(*val, addr);
174 }
175 
_stm32_qspi_poll(struct stm32_qspi_priv * priv,const struct spi_mem_op * op)176 static int _stm32_qspi_poll(struct stm32_qspi_priv *priv,
177 			    const struct spi_mem_op *op)
178 {
179 	void (*fifo)(u8 *val, void __iomem *addr);
180 	u32 len = op->data.nbytes, sr;
181 	u8 *buf;
182 	int ret;
183 
184 	if (op->data.dir == SPI_MEM_DATA_IN) {
185 		fifo = _stm32_qspi_read_fifo;
186 		buf = op->data.buf.in;
187 
188 	} else {
189 		fifo = _stm32_qspi_write_fifo;
190 		buf = (u8 *)op->data.buf.out;
191 	}
192 
193 	while (len--) {
194 		ret = readl_poll_timeout(&priv->regs->sr, sr,
195 					 sr & STM32_QSPI_SR_FTF,
196 					 STM32_QSPI_FIFO_TIMEOUT_US);
197 		if (ret) {
198 			log_err("fifo timeout (len:%d stat:%#x)\n", len, sr);
199 			return ret;
200 		}
201 
202 		fifo(buf++, &priv->regs->dr);
203 	}
204 
205 	return 0;
206 }
207 
stm32_qspi_mm(struct stm32_qspi_priv * priv,const struct spi_mem_op * op)208 static int stm32_qspi_mm(struct stm32_qspi_priv *priv,
209 			 const struct spi_mem_op *op)
210 {
211 	memcpy_fromio(op->data.buf.in, priv->mm_base + op->addr.val,
212 		      op->data.nbytes);
213 
214 	return 0;
215 }
216 
_stm32_qspi_tx(struct stm32_qspi_priv * priv,const struct spi_mem_op * op,u8 mode)217 static int _stm32_qspi_tx(struct stm32_qspi_priv *priv,
218 			  const struct spi_mem_op *op,
219 			  u8 mode)
220 {
221 	if (!op->data.nbytes)
222 		return 0;
223 
224 	if (mode == STM32_QSPI_CCR_MEM_MAP)
225 		return stm32_qspi_mm(priv, op);
226 
227 	return _stm32_qspi_poll(priv, op);
228 }
229 
_stm32_qspi_get_mode(u8 buswidth)230 static int _stm32_qspi_get_mode(u8 buswidth)
231 {
232 	if (buswidth == 4)
233 		return 3;
234 
235 	return buswidth;
236 }
237 
stm32_qspi_exec_op(struct spi_slave * slave,const struct spi_mem_op * op)238 static int stm32_qspi_exec_op(struct spi_slave *slave,
239 			      const struct spi_mem_op *op)
240 {
241 	struct stm32_qspi_priv *priv = dev_get_priv(slave->dev->parent);
242 	u32 cr, ccr, addr_max;
243 	u8 mode = STM32_QSPI_CCR_IND_WRITE;
244 	int timeout, ret;
245 
246 	dev_dbg(slave->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n",
247 		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
248 		op->dummy.buswidth, op->data.buswidth,
249 		op->addr.val, op->data.nbytes);
250 
251 	addr_max = op->addr.val + op->data.nbytes + 1;
252 
253 	if (op->data.dir == SPI_MEM_DATA_IN && op->data.nbytes) {
254 		if (addr_max < priv->mm_size && op->addr.buswidth)
255 			mode = STM32_QSPI_CCR_MEM_MAP;
256 		else
257 			mode = STM32_QSPI_CCR_IND_READ;
258 	}
259 
260 	if (op->data.nbytes)
261 		writel(op->data.nbytes - 1, &priv->regs->dlr);
262 
263 	ccr = (mode << STM32_QSPI_CCR_FMODE_SHIFT);
264 	ccr |= op->cmd.opcode;
265 	ccr |= (_stm32_qspi_get_mode(op->cmd.buswidth)
266 		<< STM32_QSPI_CCR_IMODE_SHIFT);
267 
268 	if (op->addr.nbytes) {
269 		ccr |= ((op->addr.nbytes - 1) << STM32_QSPI_CCR_ADSIZE_SHIFT);
270 		ccr |= (_stm32_qspi_get_mode(op->addr.buswidth)
271 			<< STM32_QSPI_CCR_ADMODE_SHIFT);
272 	}
273 
274 	if (op->dummy.buswidth && op->dummy.nbytes)
275 		ccr |= (op->dummy.nbytes * 8 / op->dummy.buswidth
276 			<< STM32_QSPI_CCR_DCYC_SHIFT);
277 
278 	if (op->data.nbytes)
279 		ccr |= (_stm32_qspi_get_mode(op->data.buswidth)
280 			<< STM32_QSPI_CCR_DMODE_SHIFT);
281 
282 	writel(ccr, &priv->regs->ccr);
283 
284 	if (op->addr.nbytes && mode != STM32_QSPI_CCR_MEM_MAP)
285 		writel(op->addr.val, &priv->regs->ar);
286 
287 	ret = _stm32_qspi_tx(priv, op, mode);
288 	/*
289 	 * Abort in:
290 	 * -error case
291 	 * -read memory map: prefetching must be stopped if we read the last
292 	 *  byte of device (device size - fifo size). like device size is not
293 	 *  knows, the prefetching is always stop.
294 	 */
295 	if (ret || mode == STM32_QSPI_CCR_MEM_MAP)
296 		goto abort;
297 
298 	/* Wait end of tx in indirect mode */
299 	ret = _stm32_qspi_wait_cmd(priv, op);
300 	if (ret)
301 		goto abort;
302 
303 	return 0;
304 
305 abort:
306 	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_ABORT);
307 
308 	/* Wait clear of abort bit by hw */
309 	timeout = readl_poll_timeout(&priv->regs->cr, cr,
310 				     !(cr & STM32_QSPI_CR_ABORT),
311 				     STM32_ABT_TIMEOUT_US);
312 
313 	writel(STM32_QSPI_FCR_CTCF, &priv->regs->fcr);
314 
315 	if (ret || timeout)
316 		dev_err(slave->dev, "ret:%d abort timeout:%d\n", ret, timeout);
317 
318 	return ret;
319 }
320 
stm32_qspi_probe(struct udevice * bus)321 static int stm32_qspi_probe(struct udevice *bus)
322 {
323 	struct stm32_qspi_priv *priv = dev_get_priv(bus);
324 	struct resource res;
325 	struct clk clk;
326 	struct reset_ctl reset_ctl;
327 	int ret;
328 
329 	ret = dev_read_resource_byname(bus, "qspi", &res);
330 	if (ret) {
331 		dev_err(bus, "can't get regs base addresses(ret = %d)!\n", ret);
332 		return ret;
333 	}
334 
335 	priv->regs = (struct stm32_qspi_regs *)res.start;
336 
337 	ret = dev_read_resource_byname(bus, "qspi_mm", &res);
338 	if (ret) {
339 		dev_err(bus, "can't get mmap base address(ret = %d)!\n", ret);
340 		return ret;
341 	}
342 
343 	priv->mm_base = (void __iomem *)res.start;
344 
345 	priv->mm_size = resource_size(&res);
346 	if (priv->mm_size > STM32_QSPI_MAX_MMAP_SZ)
347 		return -EINVAL;
348 
349 	dev_dbg(bus, "regs=<0x%p> mapped=<0x%p> mapped_size=<0x%lx>\n",
350 		priv->regs, priv->mm_base, priv->mm_size);
351 
352 	ret = clk_get_by_index(bus, 0, &clk);
353 	if (ret < 0)
354 		return ret;
355 
356 	ret = clk_enable(&clk);
357 	if (ret) {
358 		dev_err(bus, "failed to enable clock\n");
359 		return ret;
360 	}
361 
362 	priv->clock_rate = clk_get_rate(&clk);
363 	if (!priv->clock_rate) {
364 		clk_disable(&clk);
365 		return -EINVAL;
366 	}
367 
368 	ret = reset_get_by_index(bus, 0, &reset_ctl);
369 	if (ret) {
370 		if (ret != -ENOENT) {
371 			dev_err(bus, "failed to get reset\n");
372 			clk_disable(&clk);
373 			return ret;
374 		}
375 	} else {
376 		/* Reset QSPI controller */
377 		reset_assert(&reset_ctl);
378 		udelay(2);
379 		reset_deassert(&reset_ctl);
380 	}
381 
382 	priv->cs_used = -1;
383 
384 	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_SSHIFT);
385 
386 	/* Set dcr fsize to max address */
387 	setbits_le32(&priv->regs->dcr,
388 		     STM32_QSPI_DCR_FSIZE_MASK << STM32_QSPI_DCR_FSIZE_SHIFT);
389 
390 	return 0;
391 }
392 
stm32_qspi_claim_bus(struct udevice * dev)393 static int stm32_qspi_claim_bus(struct udevice *dev)
394 {
395 	struct stm32_qspi_priv *priv = dev_get_priv(dev->parent);
396 	struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
397 	int slave_cs = slave_plat->cs;
398 
399 	if (slave_cs >= STM32_QSPI_MAX_CHIP)
400 		return -ENODEV;
401 
402 	if (priv->cs_used != slave_cs) {
403 		priv->cs_used = slave_cs;
404 
405 		/* Set chip select */
406 		clrsetbits_le32(&priv->regs->cr, STM32_QSPI_CR_FSEL,
407 				priv->cs_used ? STM32_QSPI_CR_FSEL : 0);
408 	}
409 
410 	setbits_le32(&priv->regs->cr, STM32_QSPI_CR_EN);
411 
412 	return 0;
413 }
414 
stm32_qspi_release_bus(struct udevice * dev)415 static int stm32_qspi_release_bus(struct udevice *dev)
416 {
417 	struct stm32_qspi_priv *priv = dev_get_priv(dev->parent);
418 
419 	clrbits_le32(&priv->regs->cr, STM32_QSPI_CR_EN);
420 
421 	return 0;
422 }
423 
stm32_qspi_set_speed(struct udevice * bus,uint speed)424 static int stm32_qspi_set_speed(struct udevice *bus, uint speed)
425 {
426 	struct stm32_qspi_priv *priv = dev_get_priv(bus);
427 	u32 qspi_clk = priv->clock_rate;
428 	u32 prescaler = 255;
429 	u32 csht;
430 	int ret;
431 
432 	if (speed > 0) {
433 		prescaler = 0;
434 		if (qspi_clk) {
435 			prescaler = DIV_ROUND_UP(qspi_clk, speed) - 1;
436 			if (prescaler > 255)
437 				prescaler = 255;
438 		}
439 	}
440 
441 	csht = DIV_ROUND_UP((5 * qspi_clk) / (prescaler + 1), 100000000);
442 	csht = (csht - 1) & STM32_QSPI_DCR_CSHT_MASK;
443 
444 	ret = _stm32_qspi_wait_for_not_busy(priv);
445 	if (ret)
446 		return ret;
447 
448 	clrsetbits_le32(&priv->regs->cr,
449 			STM32_QSPI_CR_PRESCALER_MASK <<
450 			STM32_QSPI_CR_PRESCALER_SHIFT,
451 			prescaler << STM32_QSPI_CR_PRESCALER_SHIFT);
452 
453 	clrsetbits_le32(&priv->regs->dcr,
454 			STM32_QSPI_DCR_CSHT_MASK << STM32_QSPI_DCR_CSHT_SHIFT,
455 			csht << STM32_QSPI_DCR_CSHT_SHIFT);
456 
457 	dev_dbg(bus, "regs=%p, speed=%d\n", priv->regs,
458 		(qspi_clk / (prescaler + 1)));
459 
460 	return 0;
461 }
462 
stm32_qspi_set_mode(struct udevice * bus,uint mode)463 static int stm32_qspi_set_mode(struct udevice *bus, uint mode)
464 {
465 	struct stm32_qspi_priv *priv = dev_get_priv(bus);
466 	int ret;
467 	const char *str_rx, *str_tx;
468 
469 	ret = _stm32_qspi_wait_for_not_busy(priv);
470 	if (ret)
471 		return ret;
472 
473 	if ((mode & SPI_CPHA) && (mode & SPI_CPOL))
474 		setbits_le32(&priv->regs->dcr, STM32_QSPI_DCR_CKMODE);
475 	else if (!(mode & SPI_CPHA) && !(mode & SPI_CPOL))
476 		clrbits_le32(&priv->regs->dcr, STM32_QSPI_DCR_CKMODE);
477 	else
478 		return -ENODEV;
479 
480 	if (mode & SPI_CS_HIGH)
481 		return -ENODEV;
482 
483 	if (mode & SPI_RX_QUAD)
484 		str_rx = "quad";
485 	else if (mode & SPI_RX_DUAL)
486 		str_rx = "dual";
487 	else
488 		str_rx = "single";
489 
490 	if (mode & SPI_TX_QUAD)
491 		str_tx = "quad";
492 	else if (mode & SPI_TX_DUAL)
493 		str_tx = "dual";
494 	else
495 		str_tx = "single";
496 
497 	dev_dbg(bus, "regs=%p, mode=%d rx: %s, tx: %s\n",
498 		priv->regs, mode, str_rx, str_tx);
499 
500 	return 0;
501 }
502 
503 static const struct spi_controller_mem_ops stm32_qspi_mem_ops = {
504 	.exec_op = stm32_qspi_exec_op,
505 };
506 
507 static const struct dm_spi_ops stm32_qspi_ops = {
508 	.claim_bus	= stm32_qspi_claim_bus,
509 	.release_bus	= stm32_qspi_release_bus,
510 	.set_speed	= stm32_qspi_set_speed,
511 	.set_mode	= stm32_qspi_set_mode,
512 	.mem_ops	= &stm32_qspi_mem_ops,
513 };
514 
515 static const struct udevice_id stm32_qspi_ids[] = {
516 	{ .compatible = "st,stm32f469-qspi" },
517 	{ }
518 };
519 
520 U_BOOT_DRIVER(stm32_qspi) = {
521 	.name = "stm32_qspi",
522 	.id = UCLASS_SPI,
523 	.of_match = stm32_qspi_ids,
524 	.ops = &stm32_qspi_ops,
525 	.priv_auto	= sizeof(struct stm32_qspi_priv),
526 	.probe = stm32_qspi_probe,
527 };
528