xref: /freebsd/sys/arm/ti/ti_spi.c (revision 5ffd83dbcc34f10e07f6d3e968ae6365869615f4)
1 /*-
2  * Copyright (c) 2016 Rubicon Communications, LLC (Netgate)
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 <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/rman.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/sysctl.h>
40 
41 #include <machine/bus.h>
42 #include <machine/resource.h>
43 #include <machine/intr.h>
44 
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47 
48 #include <dev/spibus/spi.h>
49 #include <dev/spibus/spibusvar.h>
50 
51 #include <arm/ti/ti_sysc.h>
52 #include <arm/ti/ti_spireg.h>
53 #include <arm/ti/ti_spivar.h>
54 
55 #include "spibus_if.h"
56 
57 static void ti_spi_intr(void *);
58 static int ti_spi_detach(device_t);
59 
60 #undef TI_SPI_DEBUG
61 #ifdef TI_SPI_DEBUG
62 #define	IRQSTATUSBITS							\
63 	"\020\1TX0_EMPTY\2TX0_UNDERFLOW\3RX0_FULL\4RX0_OVERFLOW"	\
64 	"\5TX1_EMPTY\6TX1_UNDERFLOW\7RX1_FULL\11TX2_EMPTY"		\
65 	"\12TX1_UNDERFLOW\13RX2_FULL\15TX3_EMPTY\16TX3_UNDERFLOW"	\
66 	"\17RX3_FULL\22EOW"
67 #define	CONFBITS							\
68 	"\020\1PHA\2POL\7EPOL\17DMAW\20DMAR\21DPE0\22DPE1\23IS"		\
69 	"\24TURBO\25FORCE\30SBE\31SBPOL\34FFEW\35FFER\36CLKG"
70 #define	STATBITS							\
71 	"\020\1RXS\2TXS\3EOT\4TXFFE\5TXFFF\6RXFFE\7RXFFFF"
72 #define	MODULCTRLBITS							\
73 	"\020\1SINGLE\2NOSPIEN\3SLAVE\4SYST\10MOA\11FDAA"
74 #define	CTRLBITS							\
75 	"\020\1ENABLED"
76 
77 static void
78 ti_spi_printr(device_t dev)
79 {
80 	int clk, conf, ctrl, div, i, j, wl;
81 	struct ti_spi_softc *sc;
82 	uint32_t reg;
83 
84 	sc = device_get_softc(dev);
85 	reg = TI_SPI_READ(sc, MCSPI_SYSCONFIG);
86 	device_printf(dev, "SYSCONFIG: %#x\n", reg);
87 	reg = TI_SPI_READ(sc, MCSPI_SYSSTATUS);
88 	device_printf(dev, "SYSSTATUS: %#x\n", reg);
89 	reg = TI_SPI_READ(sc, MCSPI_IRQSTATUS);
90 	device_printf(dev, "IRQSTATUS: 0x%b\n", reg, IRQSTATUSBITS);
91 	reg = TI_SPI_READ(sc, MCSPI_IRQENABLE);
92 	device_printf(dev, "IRQENABLE: 0x%b\n", reg, IRQSTATUSBITS);
93 	reg = TI_SPI_READ(sc, MCSPI_MODULCTRL);
94 	device_printf(dev, "MODULCTRL: 0x%b\n", reg, MODULCTRLBITS);
95 	for (i = 0; i < sc->sc_numcs; i++) {
96 		ctrl = TI_SPI_READ(sc, MCSPI_CTRL_CH(i));
97 		conf = TI_SPI_READ(sc, MCSPI_CONF_CH(i));
98 		device_printf(dev, "CH%dCONF: 0x%b\n", i, conf, CONFBITS);
99 		if (conf & MCSPI_CONF_CLKG) {
100 			div = (conf >> MCSPI_CONF_CLK_SHIFT) & MCSPI_CONF_CLK_MSK;
101 			div |= ((ctrl >> MCSPI_CTRL_EXTCLK_SHIFT) & MCSPI_CTRL_EXTCLK_MSK) << 4;
102 		} else {
103 			div = 1;
104 			j = (conf >> MCSPI_CONF_CLK_SHIFT) & MCSPI_CONF_CLK_MSK;
105 			while (j-- > 0)
106 				div <<= 1;
107 		}
108 		clk = TI_SPI_GCLK / div;
109 		wl = ((conf >> MCSPI_CONF_WL_SHIFT) & MCSPI_CONF_WL_MSK) + 1;
110 		device_printf(dev, "wordlen: %-2d clock: %d\n", wl, clk);
111 		reg = TI_SPI_READ(sc, MCSPI_STAT_CH(i));
112 		device_printf(dev, "CH%dSTAT: 0x%b\n", i, reg, STATBITS);
113 		device_printf(dev, "CH%dCTRL: 0x%b\n", i, ctrl, CTRLBITS);
114 	}
115 	reg = TI_SPI_READ(sc, MCSPI_XFERLEVEL);
116 	device_printf(dev, "XFERLEVEL: %#x\n", reg);
117 }
118 #endif
119 
120 static void
121 ti_spi_set_clock(struct ti_spi_softc *sc, int ch, int freq)
122 {
123 	uint32_t clkdiv, conf, div, extclk, reg;
124 
125 	clkdiv = TI_SPI_GCLK / freq;
126 	if (clkdiv > MCSPI_EXTCLK_MSK) {
127 		extclk = 0;
128 		clkdiv = 0;
129 		div = 1;
130 		while (TI_SPI_GCLK / div > freq && clkdiv <= 0xf) {
131 			clkdiv++;
132 			div <<= 1;
133 		}
134 		conf = clkdiv << MCSPI_CONF_CLK_SHIFT;
135 	} else {
136 		extclk = clkdiv >> 4;
137 		clkdiv &= MCSPI_CONF_CLK_MSK;
138 		conf = MCSPI_CONF_CLKG | clkdiv << MCSPI_CONF_CLK_SHIFT;
139 	}
140 
141 	reg = TI_SPI_READ(sc, MCSPI_CTRL_CH(ch));
142 	reg &= ~(MCSPI_CTRL_EXTCLK_MSK << MCSPI_CTRL_EXTCLK_SHIFT);
143 	reg |= extclk << MCSPI_CTRL_EXTCLK_SHIFT;
144 	TI_SPI_WRITE(sc, MCSPI_CTRL_CH(ch), reg);
145 
146 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(ch));
147 	reg &= ~(MCSPI_CONF_CLKG | MCSPI_CONF_CLK_MSK << MCSPI_CONF_CLK_SHIFT);
148 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(ch), reg | conf);
149 }
150 
151 static int
152 ti_spi_probe(device_t dev)
153 {
154 
155 	if (!ofw_bus_status_okay(dev))
156 		return (ENXIO);
157 	if (!ofw_bus_is_compatible(dev, "ti,omap4-mcspi"))
158 		return (ENXIO);
159 
160 	device_set_desc(dev, "TI McSPI controller");
161 
162 	return (BUS_PROBE_DEFAULT);
163 }
164 
165 static int
166 ti_spi_attach(device_t dev)
167 {
168 	int err, i, rid, timeout;
169 	struct ti_spi_softc *sc;
170 	uint32_t rev;
171 
172 	sc = device_get_softc(dev);
173 	sc->sc_dev = dev;
174 
175 	/* Activate the McSPI module. */
176 	err = ti_sysc_clock_enable(device_get_parent(dev));
177 	if (err) {
178 		device_printf(dev, "Error: failed to activate source clock\n");
179 		return (err);
180 	}
181 
182 	/* Get the number of available channels. */
183 	if ((OF_getencprop(ofw_bus_get_node(dev), "ti,spi-num-cs",
184 	    &sc->sc_numcs, sizeof(sc->sc_numcs))) <= 0) {
185 		sc->sc_numcs = 2;
186 	}
187 
188 	rid = 0;
189 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
190 	    RF_ACTIVE);
191 	if (!sc->sc_mem_res) {
192 		device_printf(dev, "cannot allocate memory window\n");
193 		return (ENXIO);
194 	}
195 
196 	sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
197 	sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
198 
199 	rid = 0;
200 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
201 	    RF_ACTIVE);
202 	if (!sc->sc_irq_res) {
203 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
204 		device_printf(dev, "cannot allocate interrupt\n");
205 		return (ENXIO);
206 	}
207 
208 	/* Hook up our interrupt handler. */
209 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
210 	    NULL, ti_spi_intr, sc, &sc->sc_intrhand)) {
211 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
212 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
213 		device_printf(dev, "cannot setup the interrupt handler\n");
214 		return (ENXIO);
215 	}
216 
217 	mtx_init(&sc->sc_mtx, "ti_spi", NULL, MTX_DEF);
218 
219 	/* Issue a softreset to the controller */
220 	TI_SPI_WRITE(sc, MCSPI_SYSCONFIG, MCSPI_SYSCONFIG_SOFTRESET);
221 	timeout = 1000;
222 	while (!(TI_SPI_READ(sc, MCSPI_SYSSTATUS) &
223 	    MCSPI_SYSSTATUS_RESETDONE)) {
224 		if (--timeout == 0) {
225 			device_printf(dev,
226 			    "Error: Controller reset operation timed out\n");
227 			ti_spi_detach(dev);
228 			return (ENXIO);
229 		}
230 		DELAY(100);
231 	}
232 
233 	/* Print the McSPI module revision. */
234 	rev = TI_SPI_READ(sc,
235 	    ti_sysc_get_rev_address_offset_host(device_get_parent(dev)));
236 	device_printf(dev,
237 	    "scheme: %#x func: %#x rtl: %d rev: %d.%d custom rev: %d\n",
238 	    (rev >> MCSPI_REVISION_SCHEME_SHIFT) & MCSPI_REVISION_SCHEME_MSK,
239 	    (rev >> MCSPI_REVISION_FUNC_SHIFT) & MCSPI_REVISION_FUNC_MSK,
240 	    (rev >> MCSPI_REVISION_RTL_SHIFT) & MCSPI_REVISION_RTL_MSK,
241 	    (rev >> MCSPI_REVISION_MAJOR_SHIFT) & MCSPI_REVISION_MAJOR_MSK,
242 	    (rev >> MCSPI_REVISION_MINOR_SHIFT) & MCSPI_REVISION_MINOR_MSK,
243 	    (rev >> MCSPI_REVISION_CUSTOM_SHIFT) & MCSPI_REVISION_CUSTOM_MSK);
244 
245 	/* Set Master mode, single channel. */
246 	TI_SPI_WRITE(sc, MCSPI_MODULCTRL, MCSPI_MODULCTRL_SINGLE);
247 
248 	/* Clear pending interrupts and disable interrupts. */
249 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, 0x0);
250 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, 0xffff);
251 
252 	for (i = 0; i < sc->sc_numcs; i++) {
253 		/*
254 		 * Default to SPI mode 0, CS active low, 8 bits word length and
255 		 * 500kHz clock.
256 		 */
257 		TI_SPI_WRITE(sc, MCSPI_CONF_CH(i),
258 		    MCSPI_CONF_DPE0 | MCSPI_CONF_EPOL |
259 		    (8 - 1) << MCSPI_CONF_WL_SHIFT);
260 		/* Set initial clock - 500kHz. */
261 		ti_spi_set_clock(sc, i, 500000);
262 	}
263 
264 #ifdef	TI_SPI_DEBUG
265 	ti_spi_printr(dev);
266 #endif
267 
268 	device_add_child(dev, "spibus", -1);
269 
270 	return (bus_generic_attach(dev));
271 }
272 
273 static int
274 ti_spi_detach(device_t dev)
275 {
276 	struct ti_spi_softc *sc;
277 
278 	sc = device_get_softc(dev);
279 
280 	/* Clear pending interrupts and disable interrupts. */
281 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, 0);
282 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, 0xffff);
283 
284 	/* Reset controller. */
285 	TI_SPI_WRITE(sc, MCSPI_SYSCONFIG, MCSPI_SYSCONFIG_SOFTRESET);
286 
287 	bus_generic_detach(dev);
288 
289 	mtx_destroy(&sc->sc_mtx);
290 	if (sc->sc_intrhand)
291 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
292 	if (sc->sc_irq_res)
293 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
294 	if (sc->sc_mem_res)
295 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
296 
297 	return (0);
298 }
299 
300 static int
301 ti_spi_fill_fifo(struct ti_spi_softc *sc)
302 {
303 	int bytes, timeout;
304 	struct spi_command *cmd;
305 	uint32_t written;
306 	uint8_t *data;
307 
308 	cmd = sc->sc_cmd;
309 	bytes = min(sc->sc_len - sc->sc_written, sc->sc_fifolvl);
310 	while (bytes-- > 0) {
311 		data = (uint8_t *)cmd->tx_cmd;
312 		written = sc->sc_written++;
313 		if (written >= cmd->tx_cmd_sz) {
314 			data = (uint8_t *)cmd->tx_data;
315 			written -= cmd->tx_cmd_sz;
316 		}
317 		if (sc->sc_fifolvl == 1) {
318 			/* FIFO disabled. */
319 			timeout = 1000;
320 			while (--timeout > 0 && (TI_SPI_READ(sc,
321 			    MCSPI_STAT_CH(sc->sc_cs)) & MCSPI_STAT_TXS) == 0) {
322 				DELAY(100);
323 			}
324 			if (timeout == 0)
325 				return (-1);
326 		}
327 		TI_SPI_WRITE(sc, MCSPI_TX_CH(sc->sc_cs), data[written]);
328 	}
329 
330 	return (0);
331 }
332 
333 static int
334 ti_spi_drain_fifo(struct ti_spi_softc *sc)
335 {
336 	int bytes, timeout;
337 	struct spi_command *cmd;
338 	uint32_t read;
339 	uint8_t *data;
340 
341 	cmd = sc->sc_cmd;
342 	bytes = min(sc->sc_len - sc->sc_read, sc->sc_fifolvl);
343 	while (bytes-- > 0) {
344 		data = (uint8_t *)cmd->rx_cmd;
345 		read = sc->sc_read++;
346 		if (read >= cmd->rx_cmd_sz) {
347 			data = (uint8_t *)cmd->rx_data;
348 			read -= cmd->rx_cmd_sz;
349 		}
350 		if (sc->sc_fifolvl == 1) {
351 			/* FIFO disabled. */
352 			timeout = 1000;
353 			while (--timeout > 0 && (TI_SPI_READ(sc,
354 			    MCSPI_STAT_CH(sc->sc_cs)) & MCSPI_STAT_RXS) == 0) {
355 				DELAY(100);
356 			}
357 			if (timeout == 0)
358 				return (-1);
359 		}
360 		data[read] = TI_SPI_READ(sc, MCSPI_RX_CH(sc->sc_cs));
361 	}
362 
363 	return (0);
364 }
365 
366 static void
367 ti_spi_intr(void *arg)
368 {
369 	int eow;
370 	struct ti_spi_softc *sc;
371 	uint32_t status;
372 
373 	eow = 0;
374 	sc = (struct ti_spi_softc *)arg;
375 	TI_SPI_LOCK(sc);
376 	status = TI_SPI_READ(sc, MCSPI_IRQSTATUS);
377 
378 	/*
379 	 * No new TX_empty or RX_full event will be asserted while the CPU has
380 	 * not performed the number of writes or reads defined by
381 	 * MCSPI_XFERLEVEL[AEL] and MCSPI_XFERLEVEL[AFL].  It is responsibility
382 	 * of CPU perform the right number of writes and reads.
383 	 */
384 	if (status & MCSPI_IRQ_TX0_EMPTY)
385 		ti_spi_fill_fifo(sc);
386 	if (status & MCSPI_IRQ_RX0_FULL)
387 		ti_spi_drain_fifo(sc);
388 
389 	if (status & MCSPI_IRQ_EOW)
390 		eow = 1;
391 
392 	/* Clear interrupt status. */
393 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, status);
394 
395 	/* Check for end of transfer. */
396 	if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len) {
397 		sc->sc_flags |= TI_SPI_DONE;
398 		wakeup(sc->sc_dev);
399 	}
400 
401 	TI_SPI_UNLOCK(sc);
402 }
403 
404 static int
405 ti_spi_pio_transfer(struct ti_spi_softc *sc)
406 {
407 
408 	while (sc->sc_len - sc->sc_written > 0) {
409 		if (ti_spi_fill_fifo(sc) == -1)
410 			return (EIO);
411 		if (ti_spi_drain_fifo(sc) == -1)
412 			return (EIO);
413 	}
414 
415 	return (0);
416 }
417 
418 static int
419 ti_spi_gcd(int a, int b)
420 {
421 	int m;
422 
423 	while ((m = a % b) != 0) {
424 		a = b;
425 		b = m;
426 	}
427 
428 	return (b);
429 }
430 
431 static int
432 ti_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
433 {
434 	int err;
435 	struct ti_spi_softc *sc;
436 	uint32_t clockhz, cs, mode, reg;
437 
438 	sc = device_get_softc(dev);
439 
440 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
441 	    ("TX/RX command sizes should be equal"));
442 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
443 	    ("TX/RX data sizes should be equal"));
444 
445 	/* Get the proper chip select for this child. */
446 	spibus_get_cs(child, &cs);
447 	spibus_get_clock(child, &clockhz);
448 	spibus_get_mode(child, &mode);
449 
450 	cs &= ~SPIBUS_CS_HIGH;
451 
452 	if (cs > sc->sc_numcs) {
453 		device_printf(dev, "Invalid chip select %d requested by %s\n",
454 		    cs, device_get_nameunit(child));
455 		return (EINVAL);
456 	}
457 
458 	if (mode > 3)
459 	{
460 	    device_printf(dev, "Invalid mode %d requested by %s\n", mode,
461 		    device_get_nameunit(child));
462 	    return (EINVAL);
463 	}
464 
465 	TI_SPI_LOCK(sc);
466 
467 	/* If the controller is in use wait until it is available. */
468 	while (sc->sc_flags & TI_SPI_BUSY)
469 		mtx_sleep(dev, &sc->sc_mtx, 0, "ti_spi", 0);
470 
471 	/* Now we have control over SPI controller. */
472 	sc->sc_flags = TI_SPI_BUSY;
473 
474 	/* Save the SPI command data. */
475 	sc->sc_cs = cs;
476 	sc->sc_cmd = cmd;
477 	sc->sc_read = 0;
478 	sc->sc_written = 0;
479 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
480 	sc->sc_fifolvl = ti_spi_gcd(sc->sc_len, TI_SPI_FIFOSZ);
481 	if (sc->sc_fifolvl < 2 || sc->sc_len > 0xffff)
482 		sc->sc_fifolvl = 1;	/* FIFO disabled. */
483 	/* Disable FIFO for now. */
484 	sc->sc_fifolvl = 1;
485 
486 	/* Set the bus frequency. */
487 	ti_spi_set_clock(sc, sc->sc_cs, clockhz);
488 
489 	/* Disable the FIFO. */
490 	TI_SPI_WRITE(sc, MCSPI_XFERLEVEL, 0);
491 
492 	/* 8 bits word, d0 miso, d1 mosi, mode 0 and CS active low. */
493 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
494 	reg &= ~(MCSPI_CONF_FFER | MCSPI_CONF_FFEW | MCSPI_CONF_SBPOL |
495 	    MCSPI_CONF_SBE | MCSPI_CONF_TURBO | MCSPI_CONF_IS |
496 	    MCSPI_CONF_DPE1 | MCSPI_CONF_DPE0 | MCSPI_CONF_DMAR |
497 	    MCSPI_CONF_DMAW | MCSPI_CONF_EPOL);
498 	reg |= MCSPI_CONF_DPE0 | MCSPI_CONF_EPOL | MCSPI_CONF_WL8BITS;
499 	reg |= mode; /* POL and PHA are the low bits, we can just OR-in mode */
500 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg);
501 
502 #if 0
503 	/* Enable channel interrupts. */
504 	reg = TI_SPI_READ(sc, MCSPI_IRQENABLE);
505 	reg |= 0xf;
506 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, reg);
507 #endif
508 
509 	/* Start the transfer. */
510 	reg = TI_SPI_READ(sc, MCSPI_CTRL_CH(sc->sc_cs));
511 	TI_SPI_WRITE(sc, MCSPI_CTRL_CH(sc->sc_cs), reg | MCSPI_CTRL_ENABLE);
512 
513 	/* Force CS on. */
514 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
515 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg |= MCSPI_CONF_FORCE);
516 
517 	err = 0;
518 	if (sc->sc_fifolvl == 1)
519 		err = ti_spi_pio_transfer(sc);
520 
521 	/* Force CS off. */
522 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
523 	reg &= ~MCSPI_CONF_FORCE;
524 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg);
525 
526 	/* Disable IRQs. */
527 	reg = TI_SPI_READ(sc, MCSPI_IRQENABLE);
528 	reg &= ~0xf;
529 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, reg);
530 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, 0xf);
531 
532 	/* Disable the SPI channel. */
533 	reg = TI_SPI_READ(sc, MCSPI_CTRL_CH(sc->sc_cs));
534 	reg &= ~MCSPI_CTRL_ENABLE;
535 	TI_SPI_WRITE(sc, MCSPI_CTRL_CH(sc->sc_cs), reg);
536 
537 	/* Disable FIFO. */
538 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
539 	reg &= ~(MCSPI_CONF_FFER | MCSPI_CONF_FFEW);
540 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg);
541 
542 	/* Release the controller and wakeup the next thread waiting for it. */
543 	sc->sc_flags = 0;
544 	wakeup_one(dev);
545 	TI_SPI_UNLOCK(sc);
546 
547 	return (err);
548 }
549 
550 static phandle_t
551 ti_spi_get_node(device_t bus, device_t dev)
552 {
553 
554 	/* Share controller node with spibus. */
555 	return (ofw_bus_get_node(bus));
556 }
557 
558 static device_method_t ti_spi_methods[] = {
559 	/* Device interface */
560 	DEVMETHOD(device_probe,		ti_spi_probe),
561 	DEVMETHOD(device_attach,	ti_spi_attach),
562 	DEVMETHOD(device_detach,	ti_spi_detach),
563 
564 	/* SPI interface */
565 	DEVMETHOD(spibus_transfer,	ti_spi_transfer),
566 
567 	/* ofw_bus interface */
568 	DEVMETHOD(ofw_bus_get_node,	ti_spi_get_node),
569 
570 	DEVMETHOD_END
571 };
572 
573 static devclass_t ti_spi_devclass;
574 
575 static driver_t ti_spi_driver = {
576 	"spi",
577 	ti_spi_methods,
578 	sizeof(struct ti_spi_softc),
579 };
580 
581 DRIVER_MODULE(ti_spi, simplebus, ti_spi_driver, ti_spi_devclass, 0, 0);
582 MODULE_DEPEND(ti_spi, ti_sysc, 1, 1, 1);
583