xref: /freebsd/sys/dev/intel/spi.c (revision 1f40866feb2135a4cf764a07b1b90a8a3398ff0a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2016 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include "opt_acpi.h"
30 
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/proc.h>
36 #include <sys/rman.h>
37 
38 #include <machine/bus.h>
39 #include <machine/resource.h>
40 
41 #include <dev/spibus/spi.h>
42 #include <dev/spibus/spibusvar.h>
43 
44 #include <dev/intel/spi.h>
45 
46 /**
47  *	Macros for driver mutex locking
48  */
49 #define	INTELSPI_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
50 #define	INTELSPI_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
51 #define	INTELSPI_LOCK_INIT(_sc)		\
52 	mtx_init(&_sc->sc_mtx, device_get_nameunit((_sc)->sc_dev), \
53 	    "intelspi", MTX_DEF)
54 #define	INTELSPI_LOCK_DESTROY(_sc)	mtx_destroy(&(_sc)->sc_mtx)
55 #define	INTELSPI_ASSERT_LOCKED(_sc)	mtx_assert(&(_sc)->sc_mtx, MA_OWNED)
56 #define	INTELSPI_ASSERT_UNLOCKED(_sc)	mtx_assert(&(_sc)->sc_mtx, MA_NOTOWNED)
57 
58 #define INTELSPI_WRITE(_sc, _off, _val)		\
59     bus_write_4((_sc)->sc_mem_res, (_off), (_val))
60 #define INTELSPI_READ(_sc, _off)			\
61     bus_read_4((_sc)->sc_mem_res, (_off))
62 
63 #define	INTELSPI_BUSY		0x1
64 #define	TX_FIFO_THRESHOLD	2
65 #define	RX_FIFO_THRESHOLD	2
66 #define	CLOCK_DIV_10MHZ		5
67 #define	DATA_SIZE_8BITS		8
68 #define	MAX_CLOCK_RATE		50000000
69 
70 #define	CS_LOW		0
71 #define	CS_HIGH		1
72 
73 #define	INTELSPI_SSPREG_SSCR0	 	0x0
74 #define	 SSCR0_SCR(n)				((((n) - 1) & 0xfff) << 8)
75 #define	 SSCR0_SSE				(1 << 7)
76 #define	 SSCR0_FRF_SPI				(0 << 4)
77 #define	 SSCR0_DSS(n)				(((n) - 1) << 0)
78 #define	INTELSPI_SSPREG_SSCR1	 	0x4
79 #define	 SSCR1_TINTE				(1 << 19)
80 #define	 SSCR1_RFT(n)				(((n) - 1) << 10)
81 #define	 SSCR1_RFT_MASK				(0xf << 10)
82 #define	 SSCR1_TFT(n)				(((n) - 1) << 6)
83 #define	 SSCR1_SPI_SPH				(1 << 4)
84 #define	 SSCR1_SPI_SPO				(1 << 3)
85 #define	 SSCR1_MODE_MASK				(SSCR1_SPI_SPO | SSCR1_SPI_SPH)
86 #define	 SSCR1_TIE				(1 << 1)
87 #define	 SSCR1_RIE				(1 << 0)
88 #define	INTELSPI_SSPREG_SSSR	 	0x8
89 #define	 SSSR_RFL_MASK				(0xf << 12)
90 #define	 SSSR_TFL_MASK				(0xf << 8)
91 #define	 SSSR_RNE				(1 << 3)
92 #define	 SSSR_TNF				(1 << 2)
93 #define	INTELSPI_SSPREG_SSITR	 	0xC
94 #define	INTELSPI_SSPREG_SSDR	 	0x10
95 #define	INTELSPI_SSPREG_SSTO	 	0x28
96 #define	INTELSPI_SSPREG_SSPSP	 	0x2C
97 #define	INTELSPI_SSPREG_SSTSA	 	0x30
98 #define	INTELSPI_SSPREG_SSRSA	 	0x34
99 #define	INTELSPI_SSPREG_SSTSS	 	0x38
100 #define	INTELSPI_SSPREG_SSACD	 	0x3C
101 #define	INTELSPI_SSPREG_ITF	 	0x40
102 #define	INTELSPI_SSPREG_SITF	 	0x44
103 #define	INTELSPI_SSPREG_SIRF	 	0x48
104 #define SPI_CS_CTRL(sc) \
105 	(intelspi_infos[sc->sc_vers].reg_lpss_base + \
106 	 intelspi_infos[sc->sc_vers].reg_cs_ctrl)
107 #define	 SPI_CS_CTRL_CS_MASK			(3)
108 #define	 SPI_CS_CTRL_SW_MODE			(1 << 0)
109 #define	 SPI_CS_CTRL_HW_MODE			(1 << 0)
110 #define	 SPI_CS_CTRL_CS_HIGH			(1 << 1)
111 
112 static void	intelspi_intr(void *);
113 
114 static int
115 intelspi_txfifo_full(struct intelspi_softc *sc)
116 {
117 	uint32_t sssr;
118 
119 	INTELSPI_ASSERT_LOCKED(sc);
120 
121 	sssr = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
122 	if (sssr & SSSR_TNF)
123 		return (0);
124 
125 	return (1);
126 }
127 
128 static int
129 intelspi_rxfifo_empty(struct intelspi_softc *sc)
130 {
131 	uint32_t sssr;
132 
133 	INTELSPI_ASSERT_LOCKED(sc);
134 
135 	sssr = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
136 	if (sssr & SSSR_RNE)
137 		return (0);
138 	else
139 		return (1);
140 }
141 
142 static void
143 intelspi_fill_tx_fifo(struct intelspi_softc *sc)
144 {
145 	struct spi_command *cmd;
146 	uint32_t written;
147 	uint8_t *data;
148 
149 	INTELSPI_ASSERT_LOCKED(sc);
150 
151 	cmd = sc->sc_cmd;
152 	while (sc->sc_written < sc->sc_len &&
153 	    !intelspi_txfifo_full(sc)) {
154 		data = (uint8_t *)cmd->tx_cmd;
155 		written = sc->sc_written++;
156 
157 		if (written >= cmd->tx_cmd_sz) {
158 			data = (uint8_t *)cmd->tx_data;
159 			written -= cmd->tx_cmd_sz;
160 		}
161 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSDR, data[written]);
162 	}
163 }
164 
165 static void
166 intelspi_drain_rx_fifo(struct intelspi_softc *sc)
167 {
168 	struct spi_command *cmd;
169 	uint32_t  read;
170 	uint8_t *data;
171 
172 	INTELSPI_ASSERT_LOCKED(sc);
173 
174 	cmd = sc->sc_cmd;
175 	while (sc->sc_read < sc->sc_len &&
176 	    !intelspi_rxfifo_empty(sc)) {
177 		data = (uint8_t *)cmd->rx_cmd;
178 		read = sc->sc_read++;
179 		if (read >= cmd->rx_cmd_sz) {
180 			data = (uint8_t *)cmd->rx_data;
181 			read -= cmd->rx_cmd_sz;
182 		}
183 		data[read] = INTELSPI_READ(sc, INTELSPI_SSPREG_SSDR) & 0xff;
184 	}
185 }
186 
187 static int
188 intelspi_transaction_done(struct intelspi_softc *sc)
189 {
190 	int txfifo_empty;
191 	uint32_t sssr;
192 
193 	INTELSPI_ASSERT_LOCKED(sc);
194 
195 	if (sc->sc_written != sc->sc_len ||
196 	    sc->sc_read != sc->sc_len)
197 		return (0);
198 
199 	sssr = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
200 	txfifo_empty = ((sssr & SSSR_TFL_MASK) == 0) &&
201 		(sssr & SSSR_TNF);
202 
203 	if (txfifo_empty && !(sssr & SSSR_RNE))
204 		return (1);
205 
206 	return (0);
207 }
208 
209 static int
210 intelspi_transact(struct intelspi_softc *sc)
211 {
212 
213 	INTELSPI_ASSERT_LOCKED(sc);
214 
215 	/* TX - Fill up the FIFO. */
216 	intelspi_fill_tx_fifo(sc);
217 
218 	/* RX - Drain the FIFO. */
219 	intelspi_drain_rx_fifo(sc);
220 
221 	/* Check for end of transfer. */
222 	return intelspi_transaction_done(sc);
223 }
224 
225 static void
226 intelspi_intr(void *arg)
227 {
228 	struct intelspi_softc *sc;
229 	uint32_t reg;
230 
231 	sc = (struct intelspi_softc *)arg;
232 
233 	INTELSPI_LOCK(sc);
234 	if ((sc->sc_flags & INTELSPI_BUSY) == 0) {
235 		INTELSPI_UNLOCK(sc);
236 		return;
237 	}
238 
239 	/* Check if SSP if off */
240 	reg = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
241 	if (reg == 0xffffffffU) {
242 		INTELSPI_UNLOCK(sc);
243 		return;
244 	}
245 
246 	/* Check for end of transfer. */
247 	if (intelspi_transact(sc)) {
248 		/* Disable interrupts */
249 		reg = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR1);
250 		reg &= ~(SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE);
251 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, reg);
252 		wakeup(sc->sc_dev);
253 	}
254 
255 	INTELSPI_UNLOCK(sc);
256 }
257 
258 static void
259 intelspi_init(struct intelspi_softc *sc)
260 {
261 	uint32_t reg;
262 
263 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, 0);
264 
265 	/* Manual CS control */
266 	reg = INTELSPI_READ(sc, SPI_CS_CTRL(sc));
267 	reg &= ~(SPI_CS_CTRL_CS_MASK);
268 	reg |= (SPI_CS_CTRL_SW_MODE | SPI_CS_CTRL_CS_HIGH);
269 	INTELSPI_WRITE(sc, SPI_CS_CTRL(sc), reg);
270 
271 	/* Set TX/RX FIFO IRQ threshold levels */
272 	reg = SSCR1_TFT(TX_FIFO_THRESHOLD) | SSCR1_RFT(RX_FIFO_THRESHOLD);
273 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, reg);
274 
275 	reg = SSCR0_SCR(CLOCK_DIV_10MHZ);
276 	/* Put SSP in SPI mode */
277 	reg |= SSCR0_FRF_SPI;
278 	/* Data size */
279 	reg |= SSCR0_DSS(DATA_SIZE_8BITS);
280 	/* Enable SSP */
281 	reg |= SSCR0_SSE;
282 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, reg);
283 }
284 
285 static void
286 intelspi_set_cs(struct intelspi_softc *sc, int level)
287 {
288 	uint32_t reg;
289 
290 	reg = INTELSPI_READ(sc, SPI_CS_CTRL(sc));
291 	reg &= ~(SPI_CS_CTRL_CS_MASK);
292 	reg |= SPI_CS_CTRL_SW_MODE;
293 
294 	if (level == CS_HIGH)
295 		reg |= SPI_CS_CTRL_CS_HIGH;
296 
297 	INTELSPI_WRITE(sc, SPI_CS_CTRL(sc), reg);
298 }
299 
300 int
301 intelspi_transfer(device_t dev, device_t child, struct spi_command *cmd)
302 {
303 	struct intelspi_softc *sc;
304 	int err, poll_limit;
305 	uint32_t sscr0, sscr1, mode, clock, cs_delay;
306 	bool restart = false;
307 
308 	sc = device_get_softc(dev);
309 	err = 0;
310 
311 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
312 	    ("TX/RX command sizes should be equal"));
313 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
314 	    ("TX/RX data sizes should be equal"));
315 
316 	INTELSPI_LOCK(sc);
317 
318 	/* If the controller is in use wait until it is available. */
319 	while (sc->sc_flags & INTELSPI_BUSY) {
320 		if ((cmd->flags & SPI_FLAG_NO_SLEEP) == SPI_FLAG_NO_SLEEP)
321 			return (EBUSY);
322 		err = mtx_sleep(dev, &sc->sc_mtx, 0, "intelspi", 0);
323 		if (err == EINTR) {
324 			INTELSPI_UNLOCK(sc);
325 			return (err);
326 		}
327 	}
328 
329 	/* Now we have control over SPI controller. */
330 	sc->sc_flags = INTELSPI_BUSY;
331 
332 	/* Configure the clock rate and SPI mode. */
333 	spibus_get_clock(child, &clock);
334 	spibus_get_mode(child, &mode);
335 
336 	if (clock != sc->sc_clock || mode != sc->sc_mode) {
337 		sscr0 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR0);
338 		sscr0 &= ~SSCR0_SSE;
339 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, sscr0);
340 		restart = true;
341 	}
342 
343 	if (clock != sc->sc_clock) {
344 		sscr0 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR0);
345 		sscr0 &= ~SSCR0_SCR(0xfff);
346 		if (clock == 0)
347 			sscr0 |= SSCR0_SCR(CLOCK_DIV_10MHZ);
348 		else
349 			sscr0 |= SSCR0_SCR(howmany(MAX_CLOCK_RATE, min(MAX_CLOCK_RATE, clock)));
350 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, sscr0);
351 		sc->sc_clock = clock;
352 	}
353 
354 	if (mode != sc->sc_mode) {
355 		sscr1 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR1);
356 		sscr1 &= ~SSCR1_MODE_MASK;
357 		if (mode & SPIBUS_MODE_CPHA)
358 			sscr1 |= SSCR1_SPI_SPH;
359 		if (mode & SPIBUS_MODE_CPOL)
360 			sscr1 |= SSCR1_SPI_SPO;
361 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, sscr1);
362 		sc->sc_mode = mode;
363 	}
364 
365 	if (restart) {
366 		sscr0 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR0);
367 		sscr0 |= SSCR0_SSE;
368 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, sscr0);
369 	}
370 
371 	/* Save a pointer to the SPI command. */
372 	sc->sc_cmd = cmd;
373 	sc->sc_read = 0;
374 	sc->sc_written = 0;
375 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
376 
377 	/* Enable CS */
378 	intelspi_set_cs(sc, CS_LOW);
379 
380 	/* Wait the CS delay */
381 	spibus_get_cs_delay(child, &cs_delay);
382 	DELAY(cs_delay);
383 
384 	/* Transfer as much as possible to FIFOs */
385 	if ((cmd->flags & SPI_FLAG_NO_SLEEP) == SPI_FLAG_NO_SLEEP) {
386 		/* We cannot wait with mtx_sleep if we're called from e.g. an ithread */
387 		poll_limit = 2000;
388 		while (!intelspi_transact(sc) && poll_limit-- > 0)
389 			DELAY(1000);
390 		if (poll_limit == 0) {
391 			device_printf(dev, "polling was stuck, transaction not finished\n");
392 			err = EIO;
393 		}
394 	} else {
395 		if (!intelspi_transact(sc)) {
396 			/* If FIFO is not large enough - enable interrupts */
397 			sscr1 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR1);
398 			sscr1 |= (SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE);
399 			INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, sscr1);
400 
401 			/* and wait for transaction to complete */
402 			err = mtx_sleep(dev, &sc->sc_mtx, 0, "intelspi", hz * 2);
403 		}
404 	}
405 
406 	/* De-assert CS */
407 	if ((cmd->flags & SPI_FLAG_KEEP_CS) == 0)
408 		intelspi_set_cs(sc, CS_HIGH);
409 
410 	/* Clear transaction details */
411 	sc->sc_cmd = NULL;
412 	sc->sc_read = 0;
413 	sc->sc_written = 0;
414 	sc->sc_len = 0;
415 
416 	/* Make sure the SPI engine and interrupts are disabled. */
417 	sscr1 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR1);
418 	sscr1 &= ~(SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE);
419 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, sscr1);
420 
421 	/* Release the controller and wakeup the next thread waiting for it. */
422 	sc->sc_flags = 0;
423 	wakeup_one(dev);
424 	INTELSPI_UNLOCK(sc);
425 
426 	/*
427 	 * Check for transfer timeout.  The SPI controller doesn't
428 	 * return errors.
429 	 */
430 	if (err == EWOULDBLOCK) {
431 		device_printf(sc->sc_dev, "transfer timeout\n");
432 		err = EIO;
433 	}
434 
435 	return (err);
436 }
437 
438 int
439 intelspi_attach(device_t dev)
440 {
441 	struct intelspi_softc	*sc;
442 
443 	sc = device_get_softc(dev);
444 	sc->sc_dev = dev;
445 
446 	INTELSPI_LOCK_INIT(sc);
447 
448 	sc->sc_mem_res = bus_alloc_resource_any(sc->sc_dev,
449 	    SYS_RES_MEMORY, &sc->sc_mem_rid, RF_ACTIVE);
450 	if (sc->sc_mem_res == NULL) {
451 		device_printf(dev, "can't allocate memory resource\n");
452 		goto error;
453 	}
454 
455 	sc->sc_irq_res = bus_alloc_resource_any(sc->sc_dev,
456 	    SYS_RES_IRQ, &sc->sc_irq_rid, RF_ACTIVE | RF_SHAREABLE);
457 	if (sc->sc_irq_res == NULL) {
458 		device_printf(dev, "can't allocate IRQ resource\n");
459 		goto error;
460 	}
461 
462 	/* Hook up our interrupt handler. */
463 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
464 	    NULL, intelspi_intr, sc, &sc->sc_irq_ih)) {
465 		device_printf(dev, "cannot setup the interrupt handler\n");
466 		goto error;
467 	}
468 
469 	intelspi_init(sc);
470 
471 	device_add_child(dev, "spibus", -1);
472 
473 	return (bus_delayed_attach_children(dev));
474 
475 error:
476 	INTELSPI_LOCK_DESTROY(sc);
477 
478 	if (sc->sc_mem_res != NULL)
479 		bus_release_resource(dev, SYS_RES_MEMORY,
480 		    sc->sc_mem_rid, sc->sc_mem_res);
481 
482 	if (sc->sc_irq_res != NULL)
483 		bus_release_resource(dev, SYS_RES_IRQ,
484 		    sc->sc_irq_rid, sc->sc_irq_res);
485 
486 	return (ENXIO);
487 }
488 
489 int
490 intelspi_detach(device_t dev)
491 {
492 	struct intelspi_softc	*sc;
493 
494 	sc = device_get_softc(dev);
495 
496 	INTELSPI_LOCK_DESTROY(sc);
497 
498 	if (sc->sc_irq_ih)
499 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_irq_ih);
500 
501 	if (sc->sc_mem_res != NULL)
502 		bus_release_resource(dev, SYS_RES_MEMORY,
503 		    sc->sc_mem_rid, sc->sc_mem_res);
504 
505 	if (sc->sc_irq_res != NULL)
506 		bus_release_resource(dev, SYS_RES_IRQ,
507 		    sc->sc_irq_rid, sc->sc_irq_res);
508 
509 	return (bus_generic_detach(dev));
510 }
511 
512 int
513 intelspi_suspend(device_t dev)
514 {
515 	struct intelspi_softc        *sc;
516 	int err, i;
517 
518 	sc = device_get_softc(dev);
519 
520 	err = bus_generic_suspend(dev);
521 	if (err)
522 		return (err);
523 
524 	for (i = 0; i < 9; i++) {
525 		unsigned long offset = i * sizeof(uint32_t);
526 		sc->sc_regs[i] = INTELSPI_READ(sc,
527 		    intelspi_infos[sc->sc_vers].reg_lpss_base + offset);
528 	}
529 
530 	/* Shutdown just in case */
531 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, 0);
532 
533 	return (0);
534 }
535 
536 int
537 intelspi_resume(device_t dev)
538 {
539 	struct intelspi_softc   *sc;
540 	int i;
541 
542 	sc = device_get_softc(dev);
543 
544 	for (i = 0; i < 9; i++) {
545 		unsigned long offset = i * sizeof(uint32_t);
546 		INTELSPI_WRITE(sc,
547 		    intelspi_infos[sc->sc_vers].reg_lpss_base + offset,
548 		    sc->sc_regs[i]);
549 	}
550 
551 	intelspi_init(sc);
552 
553 	/* Ensure the next transfer would reconfigure these */
554 	sc->sc_clock = 0;
555 	sc->sc_mode = 0;
556 
557 	return (bus_generic_resume(dev));
558 }
559