xref: /openbmc/linux/drivers/spi/spi-stm32-qspi.c (revision be709d48)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
4  * Author: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
5  */
6 #include <linux/bitfield.h>
7 #include <linux/clk.h>
8 #include <linux/errno.h>
9 #include <linux/io.h>
10 #include <linux/iopoll.h>
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/platform_device.h>
17 #include <linux/reset.h>
18 #include <linux/sizes.h>
19 #include <linux/spi/spi-mem.h>
20 
21 #define QSPI_CR			0x00
22 #define CR_EN			BIT(0)
23 #define CR_ABORT		BIT(1)
24 #define CR_DMAEN		BIT(2)
25 #define CR_TCEN			BIT(3)
26 #define CR_SSHIFT		BIT(4)
27 #define CR_DFM			BIT(6)
28 #define CR_FSEL			BIT(7)
29 #define CR_FTHRES_MASK		GENMASK(12, 8)
30 #define CR_TEIE			BIT(16)
31 #define CR_TCIE			BIT(17)
32 #define CR_FTIE			BIT(18)
33 #define CR_SMIE			BIT(19)
34 #define CR_TOIE			BIT(20)
35 #define CR_PRESC_MASK		GENMASK(31, 24)
36 
37 #define QSPI_DCR		0x04
38 #define DCR_FSIZE_MASK		GENMASK(20, 16)
39 
40 #define QSPI_SR			0x08
41 #define SR_TEF			BIT(0)
42 #define SR_TCF			BIT(1)
43 #define SR_FTF			BIT(2)
44 #define SR_SMF			BIT(3)
45 #define SR_TOF			BIT(4)
46 #define SR_BUSY			BIT(5)
47 #define SR_FLEVEL_MASK		GENMASK(13, 8)
48 
49 #define QSPI_FCR		0x0c
50 #define FCR_CTEF		BIT(0)
51 #define FCR_CTCF		BIT(1)
52 
53 #define QSPI_DLR		0x10
54 
55 #define QSPI_CCR		0x14
56 #define CCR_INST_MASK		GENMASK(7, 0)
57 #define CCR_IMODE_MASK		GENMASK(9, 8)
58 #define CCR_ADMODE_MASK		GENMASK(11, 10)
59 #define CCR_ADSIZE_MASK		GENMASK(13, 12)
60 #define CCR_DCYC_MASK		GENMASK(22, 18)
61 #define CCR_DMODE_MASK		GENMASK(25, 24)
62 #define CCR_FMODE_MASK		GENMASK(27, 26)
63 #define CCR_FMODE_INDW		(0U << 26)
64 #define CCR_FMODE_INDR		(1U << 26)
65 #define CCR_FMODE_APM		(2U << 26)
66 #define CCR_FMODE_MM		(3U << 26)
67 #define CCR_BUSWIDTH_0		0x0
68 #define CCR_BUSWIDTH_1		0x1
69 #define CCR_BUSWIDTH_2		0x2
70 #define CCR_BUSWIDTH_4		0x3
71 
72 #define QSPI_AR			0x18
73 #define QSPI_ABR		0x1c
74 #define QSPI_DR			0x20
75 #define QSPI_PSMKR		0x24
76 #define QSPI_PSMAR		0x28
77 #define QSPI_PIR		0x2c
78 #define QSPI_LPTR		0x30
79 #define LPTR_DFT_TIMEOUT	0x10
80 
81 #define STM32_QSPI_MAX_MMAP_SZ	SZ_256M
82 #define STM32_QSPI_MAX_NORCHIP	2
83 
84 #define STM32_FIFO_TIMEOUT_US 30000
85 #define STM32_BUSY_TIMEOUT_US 100000
86 #define STM32_ABT_TIMEOUT_US 100000
87 
88 struct stm32_qspi_flash {
89 	struct stm32_qspi *qspi;
90 	u32 cs;
91 	u32 presc;
92 };
93 
94 struct stm32_qspi {
95 	struct device *dev;
96 	void __iomem *io_base;
97 	void __iomem *mm_base;
98 	resource_size_t mm_size;
99 	struct clk *clk;
100 	u32 clk_rate;
101 	struct stm32_qspi_flash flash[STM32_QSPI_MAX_NORCHIP];
102 	struct completion data_completion;
103 	u32 fmode;
104 
105 	/*
106 	 * to protect device configuration, could be different between
107 	 * 2 flash access (bk1, bk2)
108 	 */
109 	struct mutex lock;
110 };
111 
112 static irqreturn_t stm32_qspi_irq(int irq, void *dev_id)
113 {
114 	struct stm32_qspi *qspi = (struct stm32_qspi *)dev_id;
115 	u32 cr, sr;
116 
117 	sr = readl_relaxed(qspi->io_base + QSPI_SR);
118 
119 	if (sr & (SR_TEF | SR_TCF)) {
120 		/* disable irq */
121 		cr = readl_relaxed(qspi->io_base + QSPI_CR);
122 		cr &= ~CR_TCIE & ~CR_TEIE;
123 		writel_relaxed(cr, qspi->io_base + QSPI_CR);
124 		complete(&qspi->data_completion);
125 	}
126 
127 	return IRQ_HANDLED;
128 }
129 
130 static void stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
131 {
132 	*val = readb_relaxed(addr);
133 }
134 
135 static void stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
136 {
137 	writeb_relaxed(*val, addr);
138 }
139 
140 static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
141 			      const struct spi_mem_op *op)
142 {
143 	void (*tx_fifo)(u8 *val, void __iomem *addr);
144 	u32 len = op->data.nbytes, sr;
145 	u8 *buf;
146 	int ret;
147 
148 	if (op->data.dir == SPI_MEM_DATA_IN) {
149 		tx_fifo = stm32_qspi_read_fifo;
150 		buf = op->data.buf.in;
151 
152 	} else {
153 		tx_fifo = stm32_qspi_write_fifo;
154 		buf = (u8 *)op->data.buf.out;
155 	}
156 
157 	while (len--) {
158 		ret = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR,
159 							sr, (sr & SR_FTF), 1,
160 							STM32_FIFO_TIMEOUT_US);
161 		if (ret) {
162 			dev_err(qspi->dev, "fifo timeout (len:%d stat:%#x)\n",
163 				len, sr);
164 			return ret;
165 		}
166 		tx_fifo(buf++, qspi->io_base + QSPI_DR);
167 	}
168 
169 	return 0;
170 }
171 
172 static int stm32_qspi_tx_mm(struct stm32_qspi *qspi,
173 			    const struct spi_mem_op *op)
174 {
175 	memcpy_fromio(op->data.buf.in, qspi->mm_base + op->addr.val,
176 		      op->data.nbytes);
177 	return 0;
178 }
179 
180 static int stm32_qspi_tx(struct stm32_qspi *qspi, const struct spi_mem_op *op)
181 {
182 	if (!op->data.nbytes)
183 		return 0;
184 
185 	if (qspi->fmode == CCR_FMODE_MM)
186 		return stm32_qspi_tx_mm(qspi, op);
187 
188 	return stm32_qspi_tx_poll(qspi, op);
189 }
190 
191 static int stm32_qspi_wait_nobusy(struct stm32_qspi *qspi)
192 {
193 	u32 sr;
194 
195 	return readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR, sr,
196 						 !(sr & SR_BUSY), 1,
197 						 STM32_BUSY_TIMEOUT_US);
198 }
199 
200 static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi,
201 			       const struct spi_mem_op *op)
202 {
203 	u32 cr, sr;
204 	int err = 0;
205 
206 	if (!op->data.nbytes)
207 		return stm32_qspi_wait_nobusy(qspi);
208 
209 	if (readl_relaxed(qspi->io_base + QSPI_SR) & SR_TCF)
210 		goto out;
211 
212 	reinit_completion(&qspi->data_completion);
213 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
214 	writel_relaxed(cr | CR_TCIE | CR_TEIE, qspi->io_base + QSPI_CR);
215 
216 	if (!wait_for_completion_interruptible_timeout(&qspi->data_completion,
217 						msecs_to_jiffies(1000))) {
218 		err = -ETIMEDOUT;
219 	} else {
220 		sr = readl_relaxed(qspi->io_base + QSPI_SR);
221 		if (sr & SR_TEF)
222 			err = -EIO;
223 	}
224 
225 out:
226 	/* clear flags */
227 	writel_relaxed(FCR_CTCF | FCR_CTEF, qspi->io_base + QSPI_FCR);
228 
229 	return err;
230 }
231 
232 static int stm32_qspi_get_mode(struct stm32_qspi *qspi, u8 buswidth)
233 {
234 	if (buswidth == 4)
235 		return CCR_BUSWIDTH_4;
236 
237 	return buswidth;
238 }
239 
240 static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op)
241 {
242 	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
243 	struct stm32_qspi_flash *flash = &qspi->flash[mem->spi->chip_select];
244 	u32 ccr, cr, addr_max;
245 	int timeout, err = 0;
246 
247 	dev_dbg(qspi->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n",
248 		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
249 		op->dummy.buswidth, op->data.buswidth,
250 		op->addr.val, op->data.nbytes);
251 
252 	err = stm32_qspi_wait_nobusy(qspi);
253 	if (err)
254 		goto abort;
255 
256 	addr_max = op->addr.val + op->data.nbytes + 1;
257 
258 	if (op->data.dir == SPI_MEM_DATA_IN) {
259 		if (addr_max < qspi->mm_size &&
260 		    op->addr.buswidth)
261 			qspi->fmode = CCR_FMODE_MM;
262 		else
263 			qspi->fmode = CCR_FMODE_INDR;
264 	} else {
265 		qspi->fmode = CCR_FMODE_INDW;
266 	}
267 
268 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
269 	cr &= ~CR_PRESC_MASK & ~CR_FSEL;
270 	cr |= FIELD_PREP(CR_PRESC_MASK, flash->presc);
271 	cr |= FIELD_PREP(CR_FSEL, flash->cs);
272 	writel_relaxed(cr, qspi->io_base + QSPI_CR);
273 
274 	if (op->data.nbytes)
275 		writel_relaxed(op->data.nbytes - 1,
276 			       qspi->io_base + QSPI_DLR);
277 	else
278 		qspi->fmode = CCR_FMODE_INDW;
279 
280 	ccr = qspi->fmode;
281 	ccr |= FIELD_PREP(CCR_INST_MASK, op->cmd.opcode);
282 	ccr |= FIELD_PREP(CCR_IMODE_MASK,
283 			  stm32_qspi_get_mode(qspi, op->cmd.buswidth));
284 
285 	if (op->addr.nbytes) {
286 		ccr |= FIELD_PREP(CCR_ADMODE_MASK,
287 				  stm32_qspi_get_mode(qspi, op->addr.buswidth));
288 		ccr |= FIELD_PREP(CCR_ADSIZE_MASK, op->addr.nbytes - 1);
289 	}
290 
291 	if (op->dummy.buswidth && op->dummy.nbytes)
292 		ccr |= FIELD_PREP(CCR_DCYC_MASK,
293 				  op->dummy.nbytes * 8 / op->dummy.buswidth);
294 
295 	if (op->data.nbytes) {
296 		ccr |= FIELD_PREP(CCR_DMODE_MASK,
297 				  stm32_qspi_get_mode(qspi, op->data.buswidth));
298 	}
299 
300 	writel_relaxed(ccr, qspi->io_base + QSPI_CCR);
301 
302 	if (op->addr.nbytes && qspi->fmode != CCR_FMODE_MM)
303 		writel_relaxed(op->addr.val, qspi->io_base + QSPI_AR);
304 
305 	err = stm32_qspi_tx(qspi, op);
306 
307 	/*
308 	 * Abort in:
309 	 * -error case
310 	 * -read memory map: prefetching must be stopped if we read the last
311 	 *  byte of device (device size - fifo size). like device size is not
312 	 *  knows, the prefetching is always stop.
313 	 */
314 	if (err || qspi->fmode == CCR_FMODE_MM)
315 		goto abort;
316 
317 	/* wait end of tx in indirect mode */
318 	err = stm32_qspi_wait_cmd(qspi, op);
319 	if (err)
320 		goto abort;
321 
322 	return 0;
323 
324 abort:
325 	cr = readl_relaxed(qspi->io_base + QSPI_CR) | CR_ABORT;
326 	writel_relaxed(cr, qspi->io_base + QSPI_CR);
327 
328 	/* wait clear of abort bit by hw */
329 	timeout = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_CR,
330 						    cr, !(cr & CR_ABORT), 1,
331 						    STM32_ABT_TIMEOUT_US);
332 
333 	writel_relaxed(FCR_CTCF, qspi->io_base + QSPI_FCR);
334 
335 	if (err || timeout)
336 		dev_err(qspi->dev, "%s err:%d abort timeout:%d\n",
337 			__func__, err, timeout);
338 
339 	return err;
340 }
341 
342 static int stm32_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
343 {
344 	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
345 	int ret;
346 
347 	mutex_lock(&qspi->lock);
348 	ret = stm32_qspi_send(mem, op);
349 	mutex_unlock(&qspi->lock);
350 
351 	return ret;
352 }
353 
354 static int stm32_qspi_setup(struct spi_device *spi)
355 {
356 	struct spi_controller *ctrl = spi->master;
357 	struct stm32_qspi *qspi = spi_controller_get_devdata(ctrl);
358 	struct stm32_qspi_flash *flash;
359 	u32 cr, presc;
360 
361 	if (ctrl->busy)
362 		return -EBUSY;
363 
364 	if (!spi->max_speed_hz)
365 		return -EINVAL;
366 
367 	presc = DIV_ROUND_UP(qspi->clk_rate, spi->max_speed_hz) - 1;
368 
369 	flash = &qspi->flash[spi->chip_select];
370 	flash->qspi = qspi;
371 	flash->cs = spi->chip_select;
372 	flash->presc = presc;
373 
374 	mutex_lock(&qspi->lock);
375 	writel_relaxed(LPTR_DFT_TIMEOUT, qspi->io_base + QSPI_LPTR);
376 	cr = FIELD_PREP(CR_FTHRES_MASK, 3) | CR_TCEN | CR_SSHIFT | CR_EN;
377 	writel_relaxed(cr, qspi->io_base + QSPI_CR);
378 
379 	/* set dcr fsize to max address */
380 	writel_relaxed(DCR_FSIZE_MASK, qspi->io_base + QSPI_DCR);
381 	mutex_unlock(&qspi->lock);
382 
383 	return 0;
384 }
385 
386 /*
387  * no special host constraint, so use default spi_mem_default_supports_op
388  * to check supported mode.
389  */
390 static const struct spi_controller_mem_ops stm32_qspi_mem_ops = {
391 	.exec_op = stm32_qspi_exec_op,
392 };
393 
394 static void stm32_qspi_release(struct stm32_qspi *qspi)
395 {
396 	/* disable qspi */
397 	writel_relaxed(0, qspi->io_base + QSPI_CR);
398 	mutex_destroy(&qspi->lock);
399 	clk_disable_unprepare(qspi->clk);
400 }
401 
402 static int stm32_qspi_probe(struct platform_device *pdev)
403 {
404 	struct device *dev = &pdev->dev;
405 	struct spi_controller *ctrl;
406 	struct reset_control *rstc;
407 	struct stm32_qspi *qspi;
408 	struct resource *res;
409 	int ret, irq;
410 
411 	ctrl = spi_alloc_master(dev, sizeof(*qspi));
412 	if (!ctrl)
413 		return -ENOMEM;
414 
415 	qspi = spi_controller_get_devdata(ctrl);
416 
417 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi");
418 	qspi->io_base = devm_ioremap_resource(dev, res);
419 	if (IS_ERR(qspi->io_base))
420 		return PTR_ERR(qspi->io_base);
421 
422 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mm");
423 	qspi->mm_base = devm_ioremap_resource(dev, res);
424 	if (IS_ERR(qspi->mm_base))
425 		return PTR_ERR(qspi->mm_base);
426 
427 	qspi->mm_size = resource_size(res);
428 	if (qspi->mm_size > STM32_QSPI_MAX_MMAP_SZ)
429 		return -EINVAL;
430 
431 	irq = platform_get_irq(pdev, 0);
432 	ret = devm_request_irq(dev, irq, stm32_qspi_irq, 0,
433 			       dev_name(dev), qspi);
434 	if (ret) {
435 		dev_err(dev, "failed to request irq\n");
436 		return ret;
437 	}
438 
439 	init_completion(&qspi->data_completion);
440 
441 	qspi->clk = devm_clk_get(dev, NULL);
442 	if (IS_ERR(qspi->clk))
443 		return PTR_ERR(qspi->clk);
444 
445 	qspi->clk_rate = clk_get_rate(qspi->clk);
446 	if (!qspi->clk_rate)
447 		return -EINVAL;
448 
449 	ret = clk_prepare_enable(qspi->clk);
450 	if (ret) {
451 		dev_err(dev, "can not enable the clock\n");
452 		return ret;
453 	}
454 
455 	rstc = devm_reset_control_get_exclusive(dev, NULL);
456 	if (!IS_ERR(rstc)) {
457 		reset_control_assert(rstc);
458 		udelay(2);
459 		reset_control_deassert(rstc);
460 	}
461 
462 	qspi->dev = dev;
463 	platform_set_drvdata(pdev, qspi);
464 	mutex_init(&qspi->lock);
465 
466 	ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD
467 		| SPI_TX_DUAL | SPI_TX_QUAD;
468 	ctrl->setup = stm32_qspi_setup;
469 	ctrl->bus_num = -1;
470 	ctrl->mem_ops = &stm32_qspi_mem_ops;
471 	ctrl->num_chipselect = STM32_QSPI_MAX_NORCHIP;
472 	ctrl->dev.of_node = dev->of_node;
473 
474 	ret = devm_spi_register_master(dev, ctrl);
475 	if (ret)
476 		goto err_spi_register;
477 
478 	return 0;
479 
480 err_spi_register:
481 	stm32_qspi_release(qspi);
482 
483 	return ret;
484 }
485 
486 static int stm32_qspi_remove(struct platform_device *pdev)
487 {
488 	struct stm32_qspi *qspi = platform_get_drvdata(pdev);
489 
490 	stm32_qspi_release(qspi);
491 	return 0;
492 }
493 
494 static const struct of_device_id stm32_qspi_match[] = {
495 	{.compatible = "st,stm32f469-qspi"},
496 	{}
497 };
498 MODULE_DEVICE_TABLE(of, stm32_qspi_match);
499 
500 static struct platform_driver stm32_qspi_driver = {
501 	.probe	= stm32_qspi_probe,
502 	.remove	= stm32_qspi_remove,
503 	.driver	= {
504 		.name = "stm32-qspi",
505 		.of_match_table = stm32_qspi_match,
506 	},
507 };
508 module_platform_driver(stm32_qspi_driver);
509 
510 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
511 MODULE_DESCRIPTION("STMicroelectronics STM32 quad spi driver");
512 MODULE_LICENSE("GPL v2");
513