xref: /openbmc/u-boot/drivers/spi/atcspi200_spi.c (revision cd1cc31f)
1 /*
2  * Andestech ATCSPI200 SPI controller driver.
3  *
4  * Copyright 2017 Andes Technology, Inc.
5  * Author: Rick Chen (rick@andestech.com)
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <clk.h>
11 #include <common.h>
12 #include <malloc.h>
13 #include <spi.h>
14 #include <asm/io.h>
15 #include <dm.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 #define MAX_TRANSFER_LEN	512
20 #define CHUNK_SIZE		1
21 #define SPI_TIMEOUT		0x100000
22 #define SPI0_BUS		0
23 #define SPI1_BUS		1
24 #define SPI0_BASE		0xf0b00000
25 #define SPI1_BASE		0xf0f00000
26 #define NSPI_MAX_CS_NUM		1
27 
28 struct atcspi200_spi_regs {
29 	u32	rev;
30 	u32	reserve1[3];
31 	u32	format;		/* 0x10 */
32 #define DATA_LENGTH(x)	((x-1)<<8)
33 	u32	pio;
34 	u32	reserve2[2];
35 	u32	tctrl;		/* 0x20 */
36 #define TRAMODE_OFFSET	24
37 #define TRAMODE_MASK	(0x0F<<TRAMODE_OFFSET)
38 #define TRAMODE_WR_SYNC	(0<<TRAMODE_OFFSET)
39 #define TRAMODE_WO	(1<<TRAMODE_OFFSET)
40 #define TRAMODE_RO	(2<<TRAMODE_OFFSET)
41 #define TRAMODE_WR	(3<<TRAMODE_OFFSET)
42 #define TRAMODE_RW	(4<<TRAMODE_OFFSET)
43 #define TRAMODE_WDR	(5<<TRAMODE_OFFSET)
44 #define TRAMODE_RDW	(6<<TRAMODE_OFFSET)
45 #define TRAMODE_NONE	(7<<TRAMODE_OFFSET)
46 #define TRAMODE_DW	(8<<TRAMODE_OFFSET)
47 #define TRAMODE_DR	(9<<TRAMODE_OFFSET)
48 #define WCNT_OFFSET	12
49 #define WCNT_MASK	(0x1FF<<WCNT_OFFSET)
50 #define RCNT_OFFSET	0
51 #define RCNT_MASK	(0x1FF<<RCNT_OFFSET)
52 	u32	cmd;
53 	u32	addr;
54 	u32	data;
55 	u32	ctrl;		/* 0x30 */
56 #define TXFTH_OFFSET	16
57 #define RXFTH_OFFSET	8
58 #define TXDMAEN		(1<<4)
59 #define RXDMAEN		(1<<3)
60 #define TXFRST		(1<<2)
61 #define RXFRST		(1<<1)
62 #define SPIRST		(1<<0)
63 	u32	status;
64 #define TXFFL		(1<<23)
65 #define TXEPTY		(1<<22)
66 #define TXFVE_MASK	(0x1F<<16)
67 #define RXFEM		(1<<14)
68 #define RXFVE_OFFSET	(8)
69 #define RXFVE_MASK	(0x1F<<RXFVE_OFFSET)
70 #define SPIBSY		(1<<0)
71 	u32	inten;
72 	u32	intsta;
73 	u32	timing;		/* 0x40 */
74 #define SCLK_DIV_MASK	0xFF
75 };
76 
77 struct nds_spi_slave {
78 #ifndef CONFIG_DM_SPI
79 	struct spi_slave slave;
80 #endif
81 	volatile struct atcspi200_spi_regs *regs;
82 	int		to;
83 	unsigned int	freq;
84 	ulong		clock;
85 	unsigned int	mode;
86 	u8 		num_cs;
87 	unsigned int	mtiming;
88 	size_t		cmd_len;
89 	u8		cmd_buf[16];
90 	size_t		data_len;
91 	size_t		tran_len;
92 	u8		*din;
93 	u8		*dout;
94 	unsigned int    max_transfer_length;
95 };
96 
97 static int __atcspi200_spi_set_speed(struct nds_spi_slave *ns)
98 {
99 	u32 tm;
100 	u8 div;
101 	tm = ns->regs->timing;
102 	tm &= ~SCLK_DIV_MASK;
103 
104 	if(ns->freq >= ns->clock)
105 		div =0xff;
106 	else{
107 		for (div = 0; div < 0xff; div++) {
108 			if (ns->freq >= ns->clock / (2 * (div + 1)))
109 				break;
110 		}
111 	}
112 
113 	tm |= div;
114 	ns->regs->timing = tm;
115 
116 	return 0;
117 
118 }
119 
120 static int __atcspi200_spi_claim_bus(struct nds_spi_slave *ns)
121 {
122 		unsigned int format=0;
123 		ns->regs->ctrl |= (TXFRST|RXFRST|SPIRST);
124 		while((ns->regs->ctrl &(TXFRST|RXFRST|SPIRST))&&(ns->to--))
125 			if(!ns->to)
126 				return -EINVAL;
127 
128 		ns->cmd_len = 0;
129 		format = ns->mode|DATA_LENGTH(8);
130 		ns->regs->format = format;
131 		__atcspi200_spi_set_speed(ns);
132 
133 		return 0;
134 }
135 
136 static int __atcspi200_spi_release_bus(struct nds_spi_slave *ns)
137 {
138 	/* do nothing */
139 	return 0;
140 }
141 
142 static int __atcspi200_spi_start(struct nds_spi_slave *ns)
143 {
144 	int i,olen=0;
145 	int tc = ns->regs->tctrl;
146 
147 	tc &= ~(WCNT_MASK|RCNT_MASK|TRAMODE_MASK);
148 	if ((ns->din)&&(ns->cmd_len))
149 		tc |= TRAMODE_WR;
150 	else if (ns->din)
151 		tc |= TRAMODE_RO;
152 	else
153 		tc |= TRAMODE_WO;
154 
155 	if(ns->dout)
156 		olen = ns->tran_len;
157 	tc |= (ns->cmd_len+olen-1) << WCNT_OFFSET;
158 
159 	if(ns->din)
160 		tc |= (ns->tran_len-1) << RCNT_OFFSET;
161 
162 	ns->regs->tctrl = tc;
163 	ns->regs->cmd = 1;
164 
165 	for (i=0;i<ns->cmd_len;i++)
166 		ns->regs->data = ns->cmd_buf[i];
167 
168 	return 0;
169 }
170 
171 static int __atcspi200_spi_stop(struct nds_spi_slave *ns)
172 {
173 	ns->regs->timing = ns->mtiming;
174 	while ((ns->regs->status & SPIBSY)&&(ns->to--))
175 		if (!ns->to)
176 			return -EINVAL;
177 
178 	return 0;
179 }
180 
181 static void __nspi_espi_tx(struct nds_spi_slave *ns, const void *dout)
182 {
183 	ns->regs->data = *(u8 *)dout;
184 }
185 
186 static int __nspi_espi_rx(struct nds_spi_slave *ns, void *din, unsigned int bytes)
187 {
188 	*(u8 *)din = ns->regs->data;
189 	return bytes;
190 }
191 
192 
193 static int __atcspi200_spi_xfer(struct nds_spi_slave *ns,
194 		unsigned int bitlen,  const void *data_out, void *data_in,
195 		unsigned long flags)
196 {
197 		unsigned int event, rx_bytes;
198 		const void *dout = NULL;
199 		void *din = NULL;
200 		int num_blks, num_chunks, max_tran_len, tran_len;
201 		int num_bytes;
202 		u8 *cmd_buf = ns->cmd_buf;
203 		size_t cmd_len = ns->cmd_len;
204 		size_t data_len = bitlen / 8;
205 		int rf_cnt;
206 		int ret = 0;
207 
208 		max_tran_len = ns->max_transfer_length;
209 		switch (flags) {
210 		case SPI_XFER_BEGIN:
211 			cmd_len = ns->cmd_len = data_len;
212 			memcpy(cmd_buf, data_out, cmd_len);
213 			return 0;
214 
215 		case 0:
216 		case SPI_XFER_END:
217 			if (bitlen == 0) {
218 				return 0;
219 			}
220 			ns->data_len = data_len;
221 			ns->din = (u8 *)data_in;
222 			ns->dout = (u8 *)data_out;
223 			break;
224 
225 		case SPI_XFER_BEGIN | SPI_XFER_END:
226 			ns->data_len = 0;
227 			ns->din = 0;
228 			ns->dout = 0;
229 			cmd_len = ns->cmd_len = data_len;
230 			memcpy(cmd_buf, data_out, cmd_len);
231 			data_out = 0;
232 			data_len = 0;
233 			__atcspi200_spi_start(ns);
234 			break;
235 		}
236 		debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) data_len %u\n",
237 		      *(uint *)data_out, data_out, *(uint *)data_in, data_in, data_len);
238 		num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
239 		din = data_in;
240 		dout = data_out;
241 		while (num_chunks--) {
242 			tran_len = min(data_len, (size_t)max_tran_len);
243 			ns->tran_len = tran_len;
244 			num_blks = DIV_ROUND_UP(tran_len , CHUNK_SIZE);
245 			num_bytes = (tran_len) % CHUNK_SIZE;
246 			if(num_bytes == 0)
247 				num_bytes = CHUNK_SIZE;
248 			__atcspi200_spi_start(ns);
249 
250 			while (num_blks) {
251 				event = in_le32(&ns->regs->status);
252 				if ((event & TXEPTY) && (data_out)) {
253 					__nspi_espi_tx(ns, dout);
254 					num_blks -= CHUNK_SIZE;
255 					dout += CHUNK_SIZE;
256 				}
257 
258 				if ((event & RXFVE_MASK) && (data_in)) {
259 					rf_cnt = ((event & RXFVE_MASK)>> RXFVE_OFFSET);
260 					if (rf_cnt >= CHUNK_SIZE)
261 						rx_bytes = CHUNK_SIZE;
262 					else if (num_blks == 1 && rf_cnt == num_bytes)
263 						rx_bytes = num_bytes;
264 					else
265 						continue;
266 
267 					if (__nspi_espi_rx(ns, din, rx_bytes) == rx_bytes) {
268 						num_blks -= CHUNK_SIZE;
269 						din = (unsigned char *)din + rx_bytes;
270 					}
271 				}
272 			}
273 
274 			data_len -= tran_len;
275 			if(data_len)
276 			{
277 				ns->cmd_buf[1] += ((tran_len>>16)&0xff);
278 				ns->cmd_buf[2] += ((tran_len>>8)&0xff);
279 				ns->cmd_buf[3] += ((tran_len)&0xff);
280 				ns->data_len = data_len;
281 			}
282 			ret = __atcspi200_spi_stop(ns);
283 		}
284 		ret = __atcspi200_spi_stop(ns);
285 
286 		return ret;
287 }
288 
289 #ifndef CONFIG_DM_SPI
290 #define to_nds_spi_slave(s) container_of(s, struct nds_spi_slave, slave)
291 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
292 		unsigned int max_hz, unsigned int mode)
293 {
294 	struct nds_spi_slave *ns;
295 
296 	if (!spi_cs_is_valid(bus, cs))
297 		return NULL;
298 
299 	ns = spi_alloc_slave(struct nds_spi_slave, bus, cs);
300 
301 	switch (bus) {
302 	case SPI0_BUS:
303 			ns->regs = (struct atcspi200_spi_regs *)SPI0_BASE;
304 			break;
305 
306 		case SPI1_BUS:
307 			ns->regs = (struct atcspi200_spi_regs *)SPI1_BASE;
308 			break;
309 
310 		default:
311 			return NULL;
312 	}
313 
314 	ns->freq= max_hz;
315 	ns->mode = mode;
316 	ns->to = SPI_TIMEOUT;
317 	ns->max_transfer_length = MAX_TRANSFER_LEN;
318 	ns->slave.max_write_size = MAX_TRANSFER_LEN;
319 	if (!ns)
320 		return NULL;
321 
322 	return &ns->slave;
323 }
324 
325 void spi_free_slave(struct spi_slave *slave)
326 {
327 	struct nds_spi_slave *ns = to_nds_spi_slave(slave);
328 	free(ns);
329 }
330 
331 void spi_init(void)
332 {
333 	/* do nothing */
334 }
335 
336 int spi_claim_bus(struct spi_slave *slave)
337 {
338 	struct nds_spi_slave *ns = to_nds_spi_slave(slave);
339 	return __atcspi200_spi_claim_bus(ns);
340 }
341 
342 void spi_release_bus(struct spi_slave *slave)
343 {
344 	struct nds_spi_slave *ns = to_nds_spi_slave(slave);
345 	__atcspi200_spi_release_bus(ns);
346 }
347 
348 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
349 		void *data_in, unsigned long flags)
350 {
351 	struct nds_spi_slave *ns = to_nds_spi_slave(slave);
352 	return __atcspi200_spi_xfer(ns, bitlen, data_out, data_in, flags);
353 }
354 
355 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
356 {
357 	return bus == 0 && cs < NSPI_MAX_CS_NUM;
358 }
359 
360 void spi_cs_activate(struct spi_slave *slave)
361 {
362 	struct nds_spi_slave *ns = to_nds_spi_slave(slave);
363 	__atcspi200_spi_start(ns);
364 }
365 
366 void spi_cs_deactivate(struct spi_slave *slave)
367 {
368 	struct nds_spi_slave *ns = to_nds_spi_slave(slave);
369 	__atcspi200_spi_stop(ns);
370 }
371 #else
372 static int atcspi200_spi_set_speed(struct udevice *bus, uint max_hz)
373 {
374 	struct nds_spi_slave *ns = dev_get_priv(bus);
375 
376 	debug("%s speed %u\n", __func__, max_hz);
377 
378 	ns->freq = max_hz;
379 	__atcspi200_spi_set_speed(ns);
380 
381 	return 0;
382 }
383 
384 static int atcspi200_spi_set_mode(struct udevice *bus, uint mode)
385 {
386 	struct nds_spi_slave *ns = dev_get_priv(bus);
387 
388 	debug("%s mode %u\n", __func__, mode);
389 	ns->mode = mode;
390 
391 	return 0;
392 }
393 
394 static int atcspi200_spi_claim_bus(struct udevice *dev)
395 {
396 	struct dm_spi_slave_platdata *slave_plat =
397 		dev_get_parent_platdata(dev);
398 	struct udevice *bus = dev->parent;
399 	struct nds_spi_slave *ns = dev_get_priv(bus);
400 
401 	if (slave_plat->cs >= ns->num_cs) {
402 		printf("Invalid SPI chipselect\n");
403 		return -EINVAL;
404 	}
405 
406 	return __atcspi200_spi_claim_bus(ns);
407 }
408 
409 static int atcspi200_spi_release_bus(struct udevice *dev)
410 {
411 	struct nds_spi_slave *ns = dev_get_priv(dev->parent);
412 
413 	return __atcspi200_spi_release_bus(ns);
414 }
415 
416 static int atcspi200_spi_xfer(struct udevice *dev, unsigned int bitlen,
417 			    const void *dout, void *din,
418 			    unsigned long flags)
419 {
420 	struct udevice *bus = dev->parent;
421 	struct nds_spi_slave *ns = dev_get_priv(bus);
422 
423 	return __atcspi200_spi_xfer(ns, bitlen, dout, din, flags);
424 }
425 
426 static int atcspi200_spi_get_clk(struct udevice *bus)
427 {
428 	struct nds_spi_slave *ns = dev_get_priv(bus);
429 	struct clk clk;
430 	ulong clk_rate;
431 	int ret;
432 
433 	ret = clk_get_by_index(bus, 0, &clk);
434 	if (ret)
435 		return -EINVAL;
436 
437 	clk_rate = clk_get_rate(&clk);
438 	if (!clk_rate)
439 		return -EINVAL;
440 
441 	ns->clock = clk_rate;
442 	clk_free(&clk);
443 
444 	return 0;
445 }
446 
447 static int atcspi200_spi_probe(struct udevice *bus)
448 {
449 	struct nds_spi_slave *ns = dev_get_priv(bus);
450 
451 	ns->to = SPI_TIMEOUT;
452 	ns->max_transfer_length = MAX_TRANSFER_LEN;
453 	ns->mtiming = ns->regs->timing;
454 	atcspi200_spi_get_clk(bus);
455 
456 	return 0;
457 }
458 
459 static int atcspi200_ofdata_to_platadata(struct udevice *bus)
460 {
461 	struct nds_spi_slave *ns = dev_get_priv(bus);
462 	const void *blob = gd->fdt_blob;
463 	int node = dev_of_offset(bus);
464 
465 	ns->regs = map_physmem(devfdt_get_addr(bus),
466 				 sizeof(struct atcspi200_spi_regs),
467 				 MAP_NOCACHE);
468 	if (!ns->regs) {
469 		printf("%s: could not map device address\n", __func__);
470 		return -EINVAL;
471 	}
472 	ns->num_cs = fdtdec_get_int(blob, node, "num-cs", 4);
473 
474 	return 0;
475 }
476 
477 static const struct dm_spi_ops atcspi200_spi_ops = {
478 	.claim_bus	= atcspi200_spi_claim_bus,
479 	.release_bus	= atcspi200_spi_release_bus,
480 	.xfer		= atcspi200_spi_xfer,
481 	.set_speed	= atcspi200_spi_set_speed,
482 	.set_mode	= atcspi200_spi_set_mode,
483 };
484 
485 static const struct udevice_id atcspi200_spi_ids[] = {
486 	{ .compatible = "andestech,atcspi200" },
487 	{ }
488 };
489 
490 U_BOOT_DRIVER(atcspi200_spi) = {
491 	.name = "atcspi200_spi",
492 	.id = UCLASS_SPI,
493 	.of_match = atcspi200_spi_ids,
494 	.ops = &atcspi200_spi_ops,
495 	.ofdata_to_platdata = atcspi200_ofdata_to_platadata,
496 	.priv_auto_alloc_size = sizeof(struct nds_spi_slave),
497 	.probe = atcspi200_spi_probe,
498 };
499 #endif
500