xref: /openbmc/u-boot/drivers/spi/davinci_spi.c (revision e9c847c3) 
1 /*
2  * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
3  *
4  * Driver for SPI controller on DaVinci. Based on atmel_spi.c
5  * by Atmel Corporation
6  *
7  * Copyright (C) 2007 Atmel Corporation
8  *
9  * SPDX-License-Identifier:	GPL-2.0+
10  */
11 
12 #include <common.h>
13 #include <spi.h>
14 #include <malloc.h>
15 #include <asm/io.h>
16 #include <asm/arch/hardware.h>
17 #include <dm.h>
18 
19 /* SPIGCR0 */
20 #define SPIGCR0_SPIENA_MASK	0x1
21 #define SPIGCR0_SPIRST_MASK	0x0
22 
23 /* SPIGCR0 */
24 #define SPIGCR1_CLKMOD_MASK	BIT(1)
25 #define SPIGCR1_MASTER_MASK	BIT(0)
26 #define SPIGCR1_SPIENA_MASK	BIT(24)
27 
28 /* SPIPC0 */
29 #define SPIPC0_DIFUN_MASK	BIT(11)		/* SIMO */
30 #define SPIPC0_DOFUN_MASK	BIT(10)		/* SOMI */
31 #define SPIPC0_CLKFUN_MASK	BIT(9)		/* CLK */
32 #define SPIPC0_EN0FUN_MASK	BIT(0)
33 
34 /* SPIFMT0 */
35 #define SPIFMT_SHIFTDIR_SHIFT	20
36 #define SPIFMT_POLARITY_SHIFT	17
37 #define SPIFMT_PHASE_SHIFT	16
38 #define SPIFMT_PRESCALE_SHIFT	8
39 
40 /* SPIDAT1 */
41 #define SPIDAT1_CSHOLD_SHIFT	28
42 #define SPIDAT1_CSNR_SHIFT	16
43 
44 /* SPIDELAY */
45 #define SPI_C2TDELAY_SHIFT	24
46 #define SPI_T2CDELAY_SHIFT	16
47 
48 /* SPIBUF */
49 #define SPIBUF_RXEMPTY_MASK	BIT(31)
50 #define SPIBUF_TXFULL_MASK	BIT(29)
51 
52 /* SPIDEF */
53 #define SPIDEF_CSDEF0_MASK	BIT(0)
54 
55 #ifndef CONFIG_DM_SPI
56 #define SPI0_BUS		0
57 #define SPI0_BASE		CONFIG_SYS_SPI_BASE
58 /*
59  * Define default SPI0_NUM_CS as 1 for existing platforms that uses this
60  * driver. Platform can configure number of CS using CONFIG_SYS_SPI0_NUM_CS
61  * if more than one CS is supported and by defining CONFIG_SYS_SPI0.
62  */
63 #ifndef CONFIG_SYS_SPI0
64 #define SPI0_NUM_CS		1
65 #else
66 #define SPI0_NUM_CS		CONFIG_SYS_SPI0_NUM_CS
67 #endif
68 
69 /*
70  * define CONFIG_SYS_SPI1 when platform has spi-1 device (bus #1) and
71  * CONFIG_SYS_SPI1_NUM_CS defines number of CS on this bus
72  */
73 #ifdef CONFIG_SYS_SPI1
74 #define SPI1_BUS		1
75 #define SPI1_NUM_CS		CONFIG_SYS_SPI1_NUM_CS
76 #define SPI1_BASE		CONFIG_SYS_SPI1_BASE
77 #endif
78 
79 /*
80  * define CONFIG_SYS_SPI2 when platform has spi-2 device (bus #2) and
81  * CONFIG_SYS_SPI2_NUM_CS defines number of CS on this bus
82  */
83 #ifdef CONFIG_SYS_SPI2
84 #define SPI2_BUS		2
85 #define SPI2_NUM_CS		CONFIG_SYS_SPI2_NUM_CS
86 #define SPI2_BASE		CONFIG_SYS_SPI2_BASE
87 #endif
88 #endif
89 
90 DECLARE_GLOBAL_DATA_PTR;
91 
92 /* davinci spi register set */
93 struct davinci_spi_regs {
94 	dv_reg	gcr0;		/* 0x00 */
95 	dv_reg	gcr1;		/* 0x04 */
96 	dv_reg	int0;		/* 0x08 */
97 	dv_reg	lvl;		/* 0x0c */
98 	dv_reg	flg;		/* 0x10 */
99 	dv_reg	pc0;		/* 0x14 */
100 	dv_reg	pc1;		/* 0x18 */
101 	dv_reg	pc2;		/* 0x1c */
102 	dv_reg	pc3;		/* 0x20 */
103 	dv_reg	pc4;		/* 0x24 */
104 	dv_reg	pc5;		/* 0x28 */
105 	dv_reg	rsvd[3];
106 	dv_reg	dat0;		/* 0x38 */
107 	dv_reg	dat1;		/* 0x3c */
108 	dv_reg	buf;		/* 0x40 */
109 	dv_reg	emu;		/* 0x44 */
110 	dv_reg	delay;		/* 0x48 */
111 	dv_reg	def;		/* 0x4c */
112 	dv_reg	fmt0;		/* 0x50 */
113 	dv_reg	fmt1;		/* 0x54 */
114 	dv_reg	fmt2;		/* 0x58 */
115 	dv_reg	fmt3;		/* 0x5c */
116 	dv_reg	intvec0;	/* 0x60 */
117 	dv_reg	intvec1;	/* 0x64 */
118 };
119 
120 /* davinci spi slave */
121 struct davinci_spi_slave {
122 #ifndef CONFIG_DM_SPI
123 	struct spi_slave slave;
124 #endif
125 	struct davinci_spi_regs *regs;
126 	unsigned int freq; /* current SPI bus frequency */
127 	unsigned int mode; /* current SPI mode used */
128 	u8 num_cs;	   /* total no. of CS available */
129 	u8 cur_cs;	   /* CS of current slave */
130 	bool half_duplex;  /* true, if master is half-duplex only */
131 };
132 
133 /*
134  * This functions needs to act like a macro to avoid pipeline reloads in the
135  * loops below. Use always_inline. This gains us about 160KiB/s and the bloat
136  * appears to be zero bytes (da830).
137  */
138 __attribute__((always_inline))
139 static inline u32 davinci_spi_xfer_data(struct davinci_spi_slave *ds, u32 data)
140 {
141 	u32	buf_reg_val;
142 
143 	/* send out data */
144 	writel(data, &ds->regs->dat1);
145 
146 	/* wait for the data to clock in/out */
147 	while ((buf_reg_val = readl(&ds->regs->buf)) & SPIBUF_RXEMPTY_MASK)
148 		;
149 
150 	return buf_reg_val;
151 }
152 
153 static int davinci_spi_read(struct davinci_spi_slave *ds, unsigned int len,
154 			    u8 *rxp, unsigned long flags)
155 {
156 	unsigned int data1_reg_val;
157 
158 	/* enable CS hold, CS[n] and clear the data bits */
159 	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
160 			 (ds->cur_cs << SPIDAT1_CSNR_SHIFT));
161 
162 	/* wait till TXFULL is deasserted */
163 	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
164 		;
165 
166 	/* preload the TX buffer to avoid clock starvation */
167 	writel(data1_reg_val, &ds->regs->dat1);
168 
169 	/* keep reading 1 byte until only 1 byte left */
170 	while ((len--) > 1)
171 		*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);
172 
173 	/* clear CS hold when we reach the end */
174 	if (flags & SPI_XFER_END)
175 		data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
176 
177 	/* read the last byte */
178 	*rxp = davinci_spi_xfer_data(ds, data1_reg_val);
179 
180 	return 0;
181 }
182 
183 static int davinci_spi_write(struct davinci_spi_slave *ds, unsigned int len,
184 			     const u8 *txp, unsigned long flags)
185 {
186 	unsigned int data1_reg_val;
187 
188 	/* enable CS hold and clear the data bits */
189 	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
190 			 (ds->cur_cs << SPIDAT1_CSNR_SHIFT));
191 
192 	/* wait till TXFULL is deasserted */
193 	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
194 		;
195 
196 	/* preload the TX buffer to avoid clock starvation */
197 	if (len > 2) {
198 		writel(data1_reg_val | *txp++, &ds->regs->dat1);
199 		len--;
200 	}
201 
202 	/* keep writing 1 byte until only 1 byte left */
203 	while ((len--) > 1)
204 		davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
205 
206 	/* clear CS hold when we reach the end */
207 	if (flags & SPI_XFER_END)
208 		data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
209 
210 	/* write the last byte */
211 	davinci_spi_xfer_data(ds, data1_reg_val | *txp);
212 
213 	return 0;
214 }
215 
216 static int davinci_spi_read_write(struct davinci_spi_slave *ds, unsigned
217 				  int len, u8 *rxp, const u8 *txp,
218 				  unsigned long flags)
219 {
220 	unsigned int data1_reg_val;
221 
222 	/* enable CS hold and clear the data bits */
223 	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
224 			 (ds->cur_cs << SPIDAT1_CSNR_SHIFT));
225 
226 	/* wait till TXFULL is deasserted */
227 	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
228 		;
229 
230 	/* keep reading and writing 1 byte until only 1 byte left */
231 	while ((len--) > 1)
232 		*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
233 
234 	/* clear CS hold when we reach the end */
235 	if (flags & SPI_XFER_END)
236 		data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
237 
238 	/* read and write the last byte */
239 	*rxp = davinci_spi_xfer_data(ds, data1_reg_val | *txp);
240 
241 	return 0;
242 }
243 
244 
245 static int __davinci_spi_claim_bus(struct davinci_spi_slave *ds, int cs)
246 {
247 	unsigned int mode = 0, scalar;
248 
249 	/* Enable the SPI hardware */
250 	writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
251 	udelay(1000);
252 	writel(SPIGCR0_SPIENA_MASK, &ds->regs->gcr0);
253 
254 	/* Set master mode, powered up and not activated */
255 	writel(SPIGCR1_MASTER_MASK | SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1);
256 
257 	/* CS, CLK, SIMO and SOMI are functional pins */
258 	writel(((1 << cs) | SPIPC0_CLKFUN_MASK |
259 		SPIPC0_DOFUN_MASK | SPIPC0_DIFUN_MASK), &ds->regs->pc0);
260 
261 	/* setup format */
262 	scalar = ((CONFIG_SYS_SPI_CLK / ds->freq) - 1) & 0xFF;
263 
264 	/*
265 	 * Use following format:
266 	 *   character length = 8,
267 	 *   MSB shifted out first
268 	 */
269 	if (ds->mode & SPI_CPOL)
270 		mode |= SPI_CPOL;
271 	if (!(ds->mode & SPI_CPHA))
272 		mode |= SPI_CPHA;
273 	writel(8 | (scalar << SPIFMT_PRESCALE_SHIFT) |
274 		(mode << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0);
275 
276 	/*
277 	 * Including a minor delay. No science here. Should be good even with
278 	 * no delay
279 	 */
280 	writel((50 << SPI_C2TDELAY_SHIFT) |
281 		(50 << SPI_T2CDELAY_SHIFT), &ds->regs->delay);
282 
283 	/* default chip select register */
284 	writel(SPIDEF_CSDEF0_MASK, &ds->regs->def);
285 
286 	/* no interrupts */
287 	writel(0, &ds->regs->int0);
288 	writel(0, &ds->regs->lvl);
289 
290 	/* enable SPI */
291 	writel((readl(&ds->regs->gcr1) | SPIGCR1_SPIENA_MASK), &ds->regs->gcr1);
292 
293 	return 0;
294 }
295 
296 static int __davinci_spi_release_bus(struct davinci_spi_slave *ds)
297 {
298 	/* Disable the SPI hardware */
299 	writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
300 
301 	return 0;
302 }
303 
304 static int __davinci_spi_xfer(struct davinci_spi_slave *ds,
305 		unsigned int bitlen,  const void *dout, void *din,
306 		unsigned long flags)
307 {
308 	unsigned int len;
309 
310 	if (bitlen == 0)
311 		/* Finish any previously submitted transfers */
312 		goto out;
313 
314 	/*
315 	 * It's not clear how non-8-bit-aligned transfers are supposed to be
316 	 * represented as a stream of bytes...this is a limitation of
317 	 * the current SPI interface - here we terminate on receiving such a
318 	 * transfer request.
319 	 */
320 	if (bitlen % 8) {
321 		/* Errors always terminate an ongoing transfer */
322 		flags |= SPI_XFER_END;
323 		goto out;
324 	}
325 
326 	len = bitlen / 8;
327 
328 	if (!dout)
329 		return davinci_spi_read(ds, len, din, flags);
330 	if (!din)
331 		return davinci_spi_write(ds, len, dout, flags);
332 	if (!ds->half_duplex)
333 		return davinci_spi_read_write(ds, len, din, dout, flags);
334 
335 	printf("SPI full duplex not supported\n");
336 	flags |= SPI_XFER_END;
337 
338 out:
339 	if (flags & SPI_XFER_END) {
340 		u8 dummy = 0;
341 		davinci_spi_write(ds, 1, &dummy, flags);
342 	}
343 	return 0;
344 }
345 
346 #ifndef CONFIG_DM_SPI
347 
348 static inline struct davinci_spi_slave *to_davinci_spi(struct spi_slave *slave)
349 {
350 	return container_of(slave, struct davinci_spi_slave, slave);
351 }
352 
353 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
354 {
355 	int ret = 0;
356 
357 	switch (bus) {
358 	case SPI0_BUS:
359 		if (cs < SPI0_NUM_CS)
360 			ret = 1;
361 		break;
362 #ifdef CONFIG_SYS_SPI1
363 	case SPI1_BUS:
364 		if (cs < SPI1_NUM_CS)
365 			ret = 1;
366 		break;
367 #endif
368 #ifdef CONFIG_SYS_SPI2
369 	case SPI2_BUS:
370 		if (cs < SPI2_NUM_CS)
371 			ret = 1;
372 		break;
373 #endif
374 	default:
375 		/* Invalid bus number. Do nothing */
376 		break;
377 	}
378 	return ret;
379 }
380 
381 void spi_cs_activate(struct spi_slave *slave)
382 {
383 	/* do nothing */
384 }
385 
386 void spi_cs_deactivate(struct spi_slave *slave)
387 {
388 	/* do nothing */
389 }
390 
391 void spi_init(void)
392 {
393 	/* do nothing */
394 }
395 
396 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
397 			unsigned int max_hz, unsigned int mode)
398 {
399 	struct davinci_spi_slave	*ds;
400 
401 	if (!spi_cs_is_valid(bus, cs))
402 		return NULL;
403 
404 	ds = spi_alloc_slave(struct davinci_spi_slave, bus, cs);
405 	if (!ds)
406 		return NULL;
407 
408 	switch (bus) {
409 	case SPI0_BUS:
410 		ds->regs = (struct davinci_spi_regs *)SPI0_BASE;
411 		break;
412 #ifdef CONFIG_SYS_SPI1
413 	case SPI1_BUS:
414 		ds->regs = (struct davinci_spi_regs *)SPI1_BASE;
415 		break;
416 #endif
417 #ifdef CONFIG_SYS_SPI2
418 	case SPI2_BUS:
419 		ds->regs = (struct davinci_spi_regs *)SPI2_BASE;
420 		break;
421 #endif
422 	default: /* Invalid bus number */
423 		return NULL;
424 	}
425 
426 	ds->freq = max_hz;
427 	ds->mode = mode;
428 
429 	return &ds->slave;
430 }
431 
432 void spi_free_slave(struct spi_slave *slave)
433 {
434 	struct davinci_spi_slave *ds = to_davinci_spi(slave);
435 
436 	free(ds);
437 }
438 
439 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
440 	     const void *dout, void *din, unsigned long flags)
441 {
442 	struct davinci_spi_slave *ds = to_davinci_spi(slave);
443 
444 	ds->cur_cs = slave->cs;
445 
446 	return __davinci_spi_xfer(ds, bitlen, dout, din, flags);
447 }
448 
449 int spi_claim_bus(struct spi_slave *slave)
450 {
451 	struct davinci_spi_slave *ds = to_davinci_spi(slave);
452 
453 #ifdef CONFIG_SPI_HALF_DUPLEX
454 	ds->half_duplex = true;
455 #else
456 	ds->half_duplex = false;
457 #endif
458 	return __davinci_spi_claim_bus(ds, ds->slave.cs);
459 }
460 
461 void spi_release_bus(struct spi_slave *slave)
462 {
463 	struct davinci_spi_slave *ds = to_davinci_spi(slave);
464 
465 	__davinci_spi_release_bus(ds);
466 }
467 
468 #else
469 static int davinci_spi_set_speed(struct udevice *bus, uint max_hz)
470 {
471 	struct davinci_spi_slave *ds = dev_get_priv(bus);
472 
473 	debug("%s speed %u\n", __func__, max_hz);
474 	if (max_hz > CONFIG_SYS_SPI_CLK / 2)
475 		return -EINVAL;
476 
477 	ds->freq = max_hz;
478 
479 	return 0;
480 }
481 
482 static int davinci_spi_set_mode(struct udevice *bus, uint mode)
483 {
484 	struct davinci_spi_slave *ds = dev_get_priv(bus);
485 
486 	debug("%s mode %u\n", __func__, mode);
487 	ds->mode = mode;
488 
489 	return 0;
490 }
491 
492 static int davinci_spi_claim_bus(struct udevice *dev)
493 {
494 	struct dm_spi_slave_platdata *slave_plat =
495 		dev_get_parent_platdata(dev);
496 	struct udevice *bus = dev->parent;
497 	struct davinci_spi_slave *ds = dev_get_priv(bus);
498 
499 	if (slave_plat->cs >= ds->num_cs) {
500 		printf("Invalid SPI chipselect\n");
501 		return -EINVAL;
502 	}
503 	ds->half_duplex = slave_plat->mode & SPI_PREAMBLE;
504 
505 	return __davinci_spi_claim_bus(ds, slave_plat->cs);
506 }
507 
508 static int davinci_spi_release_bus(struct udevice *dev)
509 {
510 	struct davinci_spi_slave *ds = dev_get_priv(dev->parent);
511 
512 	return __davinci_spi_release_bus(ds);
513 }
514 
515 static int davinci_spi_xfer(struct udevice *dev, unsigned int bitlen,
516 			    const void *dout, void *din,
517 			    unsigned long flags)
518 {
519 	struct dm_spi_slave_platdata *slave =
520 		dev_get_parent_platdata(dev);
521 	struct udevice *bus = dev->parent;
522 	struct davinci_spi_slave *ds = dev_get_priv(bus);
523 
524 	if (slave->cs >= ds->num_cs) {
525 		printf("Invalid SPI chipselect\n");
526 		return -EINVAL;
527 	}
528 	ds->cur_cs = slave->cs;
529 
530 	return __davinci_spi_xfer(ds, bitlen, dout, din, flags);
531 }
532 
533 static int davinci_spi_probe(struct udevice *bus)
534 {
535 	/* Nothing to do */
536 	return 0;
537 }
538 
539 static int davinci_ofdata_to_platadata(struct udevice *bus)
540 {
541 	struct davinci_spi_slave *ds = dev_get_priv(bus);
542 	const void *blob = gd->fdt_blob;
543 	int node = bus->of_offset;
544 
545 	ds->regs = dev_map_physmem(bus, sizeof(struct davinci_spi_regs));
546 	if (!ds->regs) {
547 		printf("%s: could not map device address\n", __func__);
548 		return -EINVAL;
549 	}
550 	ds->num_cs = fdtdec_get_int(blob, node, "num-cs", 4);
551 
552 	return 0;
553 }
554 
555 static const struct dm_spi_ops davinci_spi_ops = {
556 	.claim_bus	= davinci_spi_claim_bus,
557 	.release_bus	= davinci_spi_release_bus,
558 	.xfer		= davinci_spi_xfer,
559 	.set_speed	= davinci_spi_set_speed,
560 	.set_mode	= davinci_spi_set_mode,
561 };
562 
563 static const struct udevice_id davinci_spi_ids[] = {
564 	{ .compatible = "ti,keystone-spi" },
565 	{ .compatible = "ti,dm6441-spi" },
566 	{ }
567 };
568 
569 U_BOOT_DRIVER(davinci_spi) = {
570 	.name = "davinci_spi",
571 	.id = UCLASS_SPI,
572 	.of_match = davinci_spi_ids,
573 	.ops = &davinci_spi_ops,
574 	.ofdata_to_platdata = davinci_ofdata_to_platadata,
575 	.priv_auto_alloc_size = sizeof(struct davinci_spi_slave),
576 	.probe = davinci_spi_probe,
577 };
578 #endif
579