xref: /freebsd/sys/dev/intel/spi.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * Copyright (c) 2016 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_acpi.h"
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/proc.h>
37 #include <sys/rman.h>
38 
39 #include <machine/bus.h>
40 #include <machine/resource.h>
41 
42 #include <dev/spibus/spi.h>
43 #include <dev/spibus/spibusvar.h>
44 
45 #include <contrib/dev/acpica/include/acpi.h>
46 #include <contrib/dev/acpica/include/accommon.h>
47 
48 #include <dev/acpica/acpivar.h>
49 
50 #include "spibus_if.h"
51 
52 /**
53  *	Macros for driver mutex locking
54  */
55 #define	INTELSPI_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
56 #define	INTELSPI_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
57 #define	INTELSPI_LOCK_INIT(_sc)		\
58 	mtx_init(&_sc->sc_mtx, device_get_nameunit((_sc)->sc_dev), \
59 	    "intelspi", MTX_DEF)
60 #define	INTELSPI_LOCK_DESTROY(_sc)	mtx_destroy(&(_sc)->sc_mtx)
61 #define	INTELSPI_ASSERT_LOCKED(_sc)	mtx_assert(&(_sc)->sc_mtx, MA_OWNED)
62 #define	INTELSPI_ASSERT_UNLOCKED(_sc)	mtx_assert(&(_sc)->sc_mtx, MA_NOTOWNED)
63 
64 #define INTELSPI_WRITE(_sc, _off, _val)		\
65     bus_write_4((_sc)->sc_mem_res, (_off), (_val))
66 #define INTELSPI_READ(_sc, _off)			\
67     bus_read_4((_sc)->sc_mem_res, (_off))
68 
69 #define	INTELSPI_BUSY		0x1
70 #define	TX_FIFO_THRESHOLD	2
71 #define	RX_FIFO_THRESHOLD	2
72 #define	CLOCK_DIV_10MHZ		5
73 #define	DATA_SIZE_8BITS		8
74 
75 #define	CS_LOW		0
76 #define	CS_HIGH		1
77 
78 #define	INTELSPI_SSPREG_SSCR0	 	0x0
79 #define	 SSCR0_SCR(n)				(((n) - 1) << 8)
80 #define	 SSCR0_SSE				(1 << 7)
81 #define	 SSCR0_FRF_SPI				(0 << 4)
82 #define	 SSCR0_DSS(n)				(((n) - 1) << 0)
83 #define	INTELSPI_SSPREG_SSCR1	 	0x4
84 #define	 SSCR1_TINTE				(1 << 19)
85 #define	 SSCR1_RFT(n)				(((n) - 1) << 10)
86 #define	 SSCR1_RFT_MASK				(0xf << 10)
87 #define	 SSCR1_TFT(n)				(((n) - 1) << 6)
88 #define	 SSCR1_SPI_SPH				(1 << 4)
89 #define	 SSCR1_SPI_SPO				(1 << 3)
90 #define	 SSCR1_MODE_MASK				(SSCR1_SPI_SPO | SSCR1_SPI_SPH)
91 #define	 SSCR1_MODE_0				(0)
92 #define	 SSCR1_MODE_1				(SSCR1_SPI_SPH)
93 #define	 SSCR1_MODE_2				(SSCR1_SPI_SPO)
94 #define	 SSCR1_MODE_3				(SSCR1_SPI_SPO | SSCR1_SPI_SPH)
95 #define	 SSCR1_TIE				(1 << 1)
96 #define	 SSCR1_RIE				(1 << 0)
97 #define	INTELSPI_SSPREG_SSSR	 	0x8
98 #define	 SSSR_RFL_MASK				(0xf << 12)
99 #define	 SSSR_TFL_MASK				(0xf << 8)
100 #define	 SSSR_RNE				(1 << 3)
101 #define	 SSSR_TNF				(1 << 2)
102 #define	INTELSPI_SSPREG_SSITR	 	0xC
103 #define	INTELSPI_SSPREG_SSDR	 	0x10
104 #define	INTELSPI_SSPREG_SSTO	 	0x28
105 #define	INTELSPI_SSPREG_SSPSP	 	0x2C
106 #define	INTELSPI_SSPREG_SSTSA	 	0x30
107 #define	INTELSPI_SSPREG_SSRSA	 	0x34
108 #define	INTELSPI_SSPREG_SSTSS	 	0x38
109 #define	INTELSPI_SSPREG_SSACD	 	0x3C
110 #define	INTELSPI_SSPREG_ITF	 	0x40
111 #define	INTELSPI_SSPREG_SITF	 	0x44
112 #define	INTELSPI_SSPREG_SIRF	 	0x48
113 #define	INTELSPI_SSPREG_PRV_CLOCK_PARAMS	0x400
114 #define	INTELSPI_SSPREG_RESETS	 	0x404
115 #define	INTELSPI_SSPREG_GENERAL	 	0x408
116 #define	INTELSPI_SSPREG_SSP_REG	 	0x40C
117 #define	INTELSPI_SSPREG_SPI_CS_CTRL	 0x418
118 #define	 SPI_CS_CTRL_CS_MASK			(3)
119 #define	 SPI_CS_CTRL_SW_MODE			(1 << 0)
120 #define	 SPI_CS_CTRL_HW_MODE			(1 << 0)
121 #define	 SPI_CS_CTRL_CS_HIGH			(1 << 1)
122 #define	 SPI_CS_CTRL_CS_LOW			(0 << 1)
123 
124 struct intelspi_softc {
125 	ACPI_HANDLE		sc_handle;
126 	device_t		sc_dev;
127 	struct mtx		sc_mtx;
128 	int			sc_mem_rid;
129 	struct resource		*sc_mem_res;
130 	int			sc_irq_rid;
131 	struct resource		*sc_irq_res;
132 	void			*sc_irq_ih;
133 	struct spi_command	*sc_cmd;
134 	uint32_t		sc_len;
135 	uint32_t		sc_read;
136 	uint32_t		sc_flags;
137 	uint32_t		sc_written;
138 };
139 
140 static int	intelspi_probe(device_t dev);
141 static int	intelspi_attach(device_t dev);
142 static int	intelspi_detach(device_t dev);
143 static void	intelspi_intr(void *);
144 
145 static int
146 intelspi_txfifo_full(struct intelspi_softc *sc)
147 {
148 	uint32_t sssr;
149 
150 	INTELSPI_ASSERT_LOCKED(sc);
151 
152 	sssr = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
153 	if (sssr & SSSR_TNF)
154 		return (0);
155 
156 	return (1);
157 }
158 
159 static int
160 intelspi_rxfifo_empty(struct intelspi_softc *sc)
161 {
162 	uint32_t sssr;
163 
164 	INTELSPI_ASSERT_LOCKED(sc);
165 
166 	sssr = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
167 	if (sssr & SSSR_RNE)
168 		return (0);
169 	else
170 		return (1);
171 }
172 
173 static void
174 intelspi_fill_tx_fifo(struct intelspi_softc *sc)
175 {
176 	struct spi_command *cmd;
177 	uint32_t written;
178 	uint8_t *data;
179 
180 	INTELSPI_ASSERT_LOCKED(sc);
181 
182 	cmd = sc->sc_cmd;
183 	while (sc->sc_written < sc->sc_len &&
184 	    !intelspi_txfifo_full(sc)) {
185 		data = (uint8_t *)cmd->tx_cmd;
186 		written = sc->sc_written++;
187 
188 		if (written >= cmd->tx_cmd_sz) {
189 			data = (uint8_t *)cmd->tx_data;
190 			written -= cmd->tx_cmd_sz;
191 		}
192 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSDR, data[written]);
193 	}
194 }
195 
196 static void
197 intelspi_drain_rx_fifo(struct intelspi_softc *sc)
198 {
199 	struct spi_command *cmd;
200 	uint32_t  read;
201 	uint8_t *data;
202 
203 	INTELSPI_ASSERT_LOCKED(sc);
204 
205 	cmd = sc->sc_cmd;
206 	while (sc->sc_read < sc->sc_len &&
207 	    !intelspi_rxfifo_empty(sc)) {
208 		data = (uint8_t *)cmd->rx_cmd;
209 		read = sc->sc_read++;
210 		if (read >= cmd->rx_cmd_sz) {
211 			data = (uint8_t *)cmd->rx_data;
212 			read -= cmd->rx_cmd_sz;
213 		}
214 		data[read] = INTELSPI_READ(sc, INTELSPI_SSPREG_SSDR) & 0xff;
215 	}
216 }
217 
218 static int
219 intelspi_transaction_done(struct intelspi_softc *sc)
220 {
221 	int txfifo_empty;
222 	uint32_t sssr;
223 
224 	INTELSPI_ASSERT_LOCKED(sc);
225 
226 	if (sc->sc_written != sc->sc_len ||
227 	    sc->sc_read != sc->sc_len)
228 		return (0);
229 
230 	sssr = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
231 	txfifo_empty = ((sssr & SSSR_TFL_MASK) == 0) &&
232 		(sssr & SSSR_TNF);
233 
234 	if (txfifo_empty && !(sssr & SSSR_RNE))
235 		return (1);
236 
237 	return (0);
238 }
239 
240 static int
241 intelspi_transact(struct intelspi_softc *sc)
242 {
243 
244 	INTELSPI_ASSERT_LOCKED(sc);
245 
246 	/* TX - Fill up the FIFO. */
247 	intelspi_fill_tx_fifo(sc);
248 
249 	/* RX - Drain the FIFO. */
250 	intelspi_drain_rx_fifo(sc);
251 
252 	/* Check for end of transfer. */
253 	return intelspi_transaction_done(sc);
254 }
255 
256 static void
257 intelspi_intr(void *arg)
258 {
259 	struct intelspi_softc *sc;
260 	uint32_t reg;
261 
262 	sc = (struct intelspi_softc *)arg;
263 
264 	INTELSPI_LOCK(sc);
265 	if ((sc->sc_flags & INTELSPI_BUSY) == 0) {
266 		INTELSPI_UNLOCK(sc);
267 		return;
268 	}
269 
270 	/* Check if SSP if off */
271 	reg = INTELSPI_READ(sc, INTELSPI_SSPREG_SSSR);
272 	if (reg == 0xffffffffU) {
273 		INTELSPI_UNLOCK(sc);
274 		return;
275 	}
276 
277 	/* Check for end of transfer. */
278 	if (intelspi_transact(sc)) {
279 		/* Disable interrupts */
280 		reg = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR1);
281 		reg &= ~(SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE);
282 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, reg);
283 		wakeup(sc->sc_dev);
284 	}
285 
286 	INTELSPI_UNLOCK(sc);
287 }
288 
289 static void
290 intelspi_init(struct intelspi_softc *sc)
291 {
292 	uint32_t reg;
293 
294 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, 0);
295 
296 	/* Manual CS control */
297 	reg = INTELSPI_READ(sc, INTELSPI_SSPREG_SPI_CS_CTRL);
298 	reg &= ~(SPI_CS_CTRL_CS_MASK);
299 	reg |= (SPI_CS_CTRL_SW_MODE | SPI_CS_CTRL_CS_HIGH);
300 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SPI_CS_CTRL, reg);
301 
302 	/* Set TX/RX FIFO IRQ threshold levels */
303 	reg = SSCR1_TFT(TX_FIFO_THRESHOLD) | SSCR1_RFT(RX_FIFO_THRESHOLD);
304 	/*
305 	 * Set SPI mode. This should be part of transaction or sysctl
306 	 */
307 	reg |= SSCR1_MODE_0;
308 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, reg);
309 
310 	/*
311 	 * Parent clock on Minowboard Turbot is 50MHz
312 	 * divide it by 5 to set to more or less reasonable
313 	 * value. But this should be part of transaction config
314 	 * or sysctl
315 	 */
316 	reg = SSCR0_SCR(CLOCK_DIV_10MHZ);
317 	/* Put SSP in SPI mode */
318 	reg |= SSCR0_FRF_SPI;
319 	/* Data size */
320 	reg |= SSCR0_DSS(DATA_SIZE_8BITS);
321 	/* Enable SSP */
322 	reg |= SSCR0_SSE;
323 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR0, reg);
324 }
325 
326 static void
327 intelspi_set_cs(struct intelspi_softc *sc, int level)
328 {
329 	uint32_t reg;
330 
331 	reg = INTELSPI_READ(sc, INTELSPI_SSPREG_SPI_CS_CTRL);
332 	reg &= ~(SPI_CS_CTRL_CS_MASK);
333 	reg |= SPI_CS_CTRL_SW_MODE;
334 
335 	if (level == CS_HIGH)
336 		reg |= SPI_CS_CTRL_CS_HIGH;
337 	else
338 		reg |= SPI_CS_CTRL_CS_LOW;
339 
340 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SPI_CS_CTRL, reg);
341 }
342 
343 static int
344 intelspi_transfer(device_t dev, device_t child, struct spi_command *cmd)
345 {
346 	struct intelspi_softc *sc;
347 	int err;
348 	uint32_t sscr1;
349 
350 	sc = device_get_softc(dev);
351 	err = 0;
352 
353 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
354 	    ("TX/RX command sizes should be equal"));
355 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
356 	    ("TX/RX data sizes should be equal"));
357 
358 	INTELSPI_LOCK(sc);
359 
360 	/* If the controller is in use wait until it is available. */
361 	while (sc->sc_flags & INTELSPI_BUSY) {
362 		err = mtx_sleep(dev, &sc->sc_mtx, 0, "intelspi", 0);
363 		if (err == EINTR) {
364 			INTELSPI_UNLOCK(sc);
365 			return (err);
366 		}
367 	}
368 
369 	/* Now we have control over SPI controller. */
370 	sc->sc_flags = INTELSPI_BUSY;
371 
372 	/* Save a pointer to the SPI command. */
373 	sc->sc_cmd = cmd;
374 	sc->sc_read = 0;
375 	sc->sc_written = 0;
376 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
377 
378 	/* Enable CS */
379 	intelspi_set_cs(sc, CS_LOW);
380 	/* Transfer as much as possible to FIFOs */
381 	if (!intelspi_transact(sc)) {
382 		/* If FIFO is not large enough - enable interrupts */
383 		sscr1 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR1);
384 		sscr1 |= (SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE);
385 		INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, sscr1);
386 
387 		/* and wait for transaction to complete */
388 		err = mtx_sleep(dev, &sc->sc_mtx, 0, "intelspi", hz * 2);
389 	}
390 
391 	/* de-asser CS */
392 	intelspi_set_cs(sc, CS_HIGH);
393 
394 	/* Clear transaction details */
395 	sc->sc_cmd = NULL;
396 	sc->sc_read = 0;
397 	sc->sc_written = 0;
398 	sc->sc_len = 0;
399 
400 	/* Make sure the SPI engine and interrupts are disabled. */
401 	sscr1 = INTELSPI_READ(sc, INTELSPI_SSPREG_SSCR1);
402 	sscr1 &= ~(SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE);
403 	INTELSPI_WRITE(sc, INTELSPI_SSPREG_SSCR1, sscr1);
404 
405 	/* Release the controller and wakeup the next thread waiting for it. */
406 	sc->sc_flags = 0;
407 	wakeup_one(dev);
408 	INTELSPI_UNLOCK(sc);
409 
410 	/*
411 	 * Check for transfer timeout.  The SPI controller doesn't
412 	 * return errors.
413 	 */
414 	if (err == EWOULDBLOCK) {
415 		device_printf(sc->sc_dev, "transfer timeout\n");
416 		err = EIO;
417 	}
418 
419 	return (err);
420 }
421 
422 static int
423 intelspi_probe(device_t dev)
424 {
425 	static char *gpio_ids[] = { "80860F0E", NULL };
426 
427 	if (acpi_disabled("spi") ||
428 	    ACPI_ID_PROBE(device_get_parent(dev), dev, gpio_ids) == NULL)
429 	return (ENXIO);
430 
431 	device_set_desc(dev, "Intel SPI Controller");
432 	return (0);
433 }
434 
435 static int
436 intelspi_attach(device_t dev)
437 {
438 	struct intelspi_softc	*sc;
439 
440 	sc = device_get_softc(dev);
441 	sc->sc_dev = dev;
442 	sc->sc_handle = acpi_get_handle(dev);
443 
444 	INTELSPI_LOCK_INIT(sc);
445 
446 	sc->sc_mem_rid = 0;
447 	sc->sc_mem_res = bus_alloc_resource_any(sc->sc_dev,
448 	    SYS_RES_MEMORY, &sc->sc_mem_rid, RF_ACTIVE);
449 	if (sc->sc_mem_res == NULL) {
450 		device_printf(dev, "can't allocate memory resource\n");
451 		goto error;
452 	}
453 
454 	sc->sc_irq_rid = 0;
455 	sc->sc_irq_res = bus_alloc_resource_any(sc->sc_dev,
456 	    SYS_RES_IRQ, &sc->sc_irq_rid, RF_ACTIVE);
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_generic_attach(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_MEMORY,
484 		    sc->sc_irq_rid, sc->sc_irq_res);
485 
486 	return (ENXIO);
487 }
488 
489 static 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_MEMORY,
507 		    sc->sc_irq_rid, sc->sc_irq_res);
508 
509 	return (0);
510 }
511 
512 static device_method_t intelspi_methods[] = {
513 	/* Device interface */
514 	DEVMETHOD(device_probe, intelspi_probe),
515 	DEVMETHOD(device_attach, intelspi_attach),
516 	DEVMETHOD(device_detach, intelspi_detach),
517 
518 	/* SPI interface */
519 	DEVMETHOD(spibus_transfer,	intelspi_transfer),
520 
521 	DEVMETHOD_END
522 };
523 
524 static driver_t intelspi_driver = {
525 	"spi",
526 	intelspi_methods,
527 	sizeof(struct intelspi_softc),
528 };
529 
530 static devclass_t intelspi_devclass;
531 DRIVER_MODULE(intelspi, acpi, intelspi_driver, intelspi_devclass, 0, 0);
532 MODULE_DEPEND(intelspi, acpi, 1, 1, 1);
533 MODULE_DEPEND(intelspi, spibus, 1, 1, 1);
534