xref: /freebsd/sys/arm/ti/ti_spi.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/bus.h>
31 
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/rman.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/sysctl.h>
38 
39 #include <machine/bus.h>
40 #include <machine/resource.h>
41 #include <machine/intr.h>
42 
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include <dev/spibus/spi.h>
47 #include <dev/spibus/spibusvar.h>
48 
49 #include <arm/ti/ti_sysc.h>
50 #include <arm/ti/ti_spireg.h>
51 #include <arm/ti/ti_spivar.h>
52 
53 #include "spibus_if.h"
54 
55 static void ti_spi_intr(void *);
56 static int ti_spi_detach(device_t);
57 
58 #undef TI_SPI_DEBUG
59 #ifdef TI_SPI_DEBUG
60 #define	IRQSTATUSBITS							\
61 	"\020\1TX0_EMPTY\2TX0_UNDERFLOW\3RX0_FULL\4RX0_OVERFLOW"	\
62 	"\5TX1_EMPTY\6TX1_UNDERFLOW\7RX1_FULL\11TX2_EMPTY"		\
63 	"\12TX1_UNDERFLOW\13RX2_FULL\15TX3_EMPTY\16TX3_UNDERFLOW"	\
64 	"\17RX3_FULL\22EOW"
65 #define	CONFBITS							\
66 	"\020\1PHA\2POL\7EPOL\17DMAW\20DMAR\21DPE0\22DPE1\23IS"		\
67 	"\24TURBO\25FORCE\30SBE\31SBPOL\34FFEW\35FFER\36CLKG"
68 #define	STATBITS							\
69 	"\020\1RXS\2TXS\3EOT\4TXFFE\5TXFFF\6RXFFE\7RXFFFF"
70 #define	MODULCTRLBITS							\
71 	"\020\1SINGLE\2NOSPIEN\3SLAVE\4SYST\10MOA\11FDAA"
72 #define	CTRLBITS							\
73 	"\020\1ENABLED"
74 
75 static void
76 ti_spi_printr(device_t dev)
77 {
78 	int clk, conf, ctrl, div, i, j, wl;
79 	struct ti_spi_softc *sc;
80 	uint32_t reg;
81 
82 	sc = device_get_softc(dev);
83 	reg = TI_SPI_READ(sc, MCSPI_SYSCONFIG);
84 	device_printf(dev, "SYSCONFIG: %#x\n", reg);
85 	reg = TI_SPI_READ(sc, MCSPI_SYSSTATUS);
86 	device_printf(dev, "SYSSTATUS: %#x\n", reg);
87 	reg = TI_SPI_READ(sc, MCSPI_IRQSTATUS);
88 	device_printf(dev, "IRQSTATUS: 0x%b\n", reg, IRQSTATUSBITS);
89 	reg = TI_SPI_READ(sc, MCSPI_IRQENABLE);
90 	device_printf(dev, "IRQENABLE: 0x%b\n", reg, IRQSTATUSBITS);
91 	reg = TI_SPI_READ(sc, MCSPI_MODULCTRL);
92 	device_printf(dev, "MODULCTRL: 0x%b\n", reg, MODULCTRLBITS);
93 	for (i = 0; i < sc->sc_numcs; i++) {
94 		ctrl = TI_SPI_READ(sc, MCSPI_CTRL_CH(i));
95 		conf = TI_SPI_READ(sc, MCSPI_CONF_CH(i));
96 		device_printf(dev, "CH%dCONF: 0x%b\n", i, conf, CONFBITS);
97 		if (conf & MCSPI_CONF_CLKG) {
98 			div = (conf >> MCSPI_CONF_CLK_SHIFT) & MCSPI_CONF_CLK_MSK;
99 			div |= ((ctrl >> MCSPI_CTRL_EXTCLK_SHIFT) & MCSPI_CTRL_EXTCLK_MSK) << 4;
100 		} else {
101 			div = 1;
102 			j = (conf >> MCSPI_CONF_CLK_SHIFT) & MCSPI_CONF_CLK_MSK;
103 			while (j-- > 0)
104 				div <<= 1;
105 		}
106 		clk = TI_SPI_GCLK / div;
107 		wl = ((conf >> MCSPI_CONF_WL_SHIFT) & MCSPI_CONF_WL_MSK) + 1;
108 		device_printf(dev, "wordlen: %-2d clock: %d\n", wl, clk);
109 		reg = TI_SPI_READ(sc, MCSPI_STAT_CH(i));
110 		device_printf(dev, "CH%dSTAT: 0x%b\n", i, reg, STATBITS);
111 		device_printf(dev, "CH%dCTRL: 0x%b\n", i, ctrl, CTRLBITS);
112 	}
113 	reg = TI_SPI_READ(sc, MCSPI_XFERLEVEL);
114 	device_printf(dev, "XFERLEVEL: %#x\n", reg);
115 }
116 #endif
117 
118 static void
119 ti_spi_set_clock(struct ti_spi_softc *sc, int ch, int freq)
120 {
121 	uint32_t clkdiv, conf, div, extclk, reg;
122 
123 	clkdiv = TI_SPI_GCLK / freq;
124 	if (clkdiv > MCSPI_EXTCLK_MSK) {
125 		extclk = 0;
126 		clkdiv = 0;
127 		div = 1;
128 		while (TI_SPI_GCLK / div > freq && clkdiv <= 0xf) {
129 			clkdiv++;
130 			div <<= 1;
131 		}
132 		conf = clkdiv << MCSPI_CONF_CLK_SHIFT;
133 	} else {
134 		extclk = clkdiv >> 4;
135 		clkdiv &= MCSPI_CONF_CLK_MSK;
136 		conf = MCSPI_CONF_CLKG | clkdiv << MCSPI_CONF_CLK_SHIFT;
137 	}
138 
139 	reg = TI_SPI_READ(sc, MCSPI_CTRL_CH(ch));
140 	reg &= ~(MCSPI_CTRL_EXTCLK_MSK << MCSPI_CTRL_EXTCLK_SHIFT);
141 	reg |= extclk << MCSPI_CTRL_EXTCLK_SHIFT;
142 	TI_SPI_WRITE(sc, MCSPI_CTRL_CH(ch), reg);
143 
144 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(ch));
145 	reg &= ~(MCSPI_CONF_CLKG | MCSPI_CONF_CLK_MSK << MCSPI_CONF_CLK_SHIFT);
146 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(ch), reg | conf);
147 }
148 
149 static int
150 ti_spi_probe(device_t dev)
151 {
152 
153 	if (!ofw_bus_status_okay(dev))
154 		return (ENXIO);
155 	if (!ofw_bus_is_compatible(dev, "ti,omap4-mcspi"))
156 		return (ENXIO);
157 
158 	device_set_desc(dev, "TI McSPI controller");
159 
160 	return (BUS_PROBE_DEFAULT);
161 }
162 
163 static int
164 ti_spi_attach(device_t dev)
165 {
166 	int err, i, rid, timeout;
167 	struct ti_spi_softc *sc;
168 	uint32_t rev;
169 
170 	sc = device_get_softc(dev);
171 	sc->sc_dev = dev;
172 
173 	/* Activate the McSPI module. */
174 	err = ti_sysc_clock_enable(device_get_parent(dev));
175 	if (err) {
176 		device_printf(dev, "Error: failed to activate source clock\n");
177 		return (err);
178 	}
179 
180 	/* Get the number of available channels. */
181 	if ((OF_getencprop(ofw_bus_get_node(dev), "ti,spi-num-cs",
182 	    &sc->sc_numcs, sizeof(sc->sc_numcs))) <= 0) {
183 		sc->sc_numcs = 2;
184 	}
185 
186 	rid = 0;
187 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
188 	    RF_ACTIVE);
189 	if (!sc->sc_mem_res) {
190 		device_printf(dev, "cannot allocate memory window\n");
191 		return (ENXIO);
192 	}
193 
194 	sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
195 	sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
196 
197 	rid = 0;
198 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
199 	    RF_ACTIVE);
200 	if (!sc->sc_irq_res) {
201 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
202 		device_printf(dev, "cannot allocate interrupt\n");
203 		return (ENXIO);
204 	}
205 
206 	/* Hook up our interrupt handler. */
207 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
208 	    NULL, ti_spi_intr, sc, &sc->sc_intrhand)) {
209 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
210 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
211 		device_printf(dev, "cannot setup the interrupt handler\n");
212 		return (ENXIO);
213 	}
214 
215 	mtx_init(&sc->sc_mtx, "ti_spi", NULL, MTX_DEF);
216 
217 	/* Issue a softreset to the controller */
218 	TI_SPI_WRITE(sc, MCSPI_SYSCONFIG, MCSPI_SYSCONFIG_SOFTRESET);
219 	timeout = 1000;
220 	while (!(TI_SPI_READ(sc, MCSPI_SYSSTATUS) &
221 	    MCSPI_SYSSTATUS_RESETDONE)) {
222 		if (--timeout == 0) {
223 			device_printf(dev,
224 			    "Error: Controller reset operation timed out\n");
225 			ti_spi_detach(dev);
226 			return (ENXIO);
227 		}
228 		DELAY(100);
229 	}
230 
231 	/* Print the McSPI module revision. */
232 	rev = TI_SPI_READ(sc,
233 	    ti_sysc_get_rev_address_offset_host(device_get_parent(dev)));
234 	device_printf(dev,
235 	    "scheme: %#x func: %#x rtl: %d rev: %d.%d custom rev: %d\n",
236 	    (rev >> MCSPI_REVISION_SCHEME_SHIFT) & MCSPI_REVISION_SCHEME_MSK,
237 	    (rev >> MCSPI_REVISION_FUNC_SHIFT) & MCSPI_REVISION_FUNC_MSK,
238 	    (rev >> MCSPI_REVISION_RTL_SHIFT) & MCSPI_REVISION_RTL_MSK,
239 	    (rev >> MCSPI_REVISION_MAJOR_SHIFT) & MCSPI_REVISION_MAJOR_MSK,
240 	    (rev >> MCSPI_REVISION_MINOR_SHIFT) & MCSPI_REVISION_MINOR_MSK,
241 	    (rev >> MCSPI_REVISION_CUSTOM_SHIFT) & MCSPI_REVISION_CUSTOM_MSK);
242 
243 	/* Set Master mode, single channel. */
244 	TI_SPI_WRITE(sc, MCSPI_MODULCTRL, MCSPI_MODULCTRL_SINGLE);
245 
246 	/* Clear pending interrupts and disable interrupts. */
247 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, 0x0);
248 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, 0xffff);
249 
250 	for (i = 0; i < sc->sc_numcs; i++) {
251 		/*
252 		 * Default to SPI mode 0, CS active low, 8 bits word length and
253 		 * 500kHz clock.
254 		 */
255 		TI_SPI_WRITE(sc, MCSPI_CONF_CH(i),
256 		    MCSPI_CONF_DPE0 | MCSPI_CONF_EPOL |
257 		    (8 - 1) << MCSPI_CONF_WL_SHIFT);
258 		/* Set initial clock - 500kHz. */
259 		ti_spi_set_clock(sc, i, 500000);
260 	}
261 
262 #ifdef	TI_SPI_DEBUG
263 	ti_spi_printr(dev);
264 #endif
265 
266 	device_add_child(dev, "spibus", -1);
267 
268 	return (bus_generic_attach(dev));
269 }
270 
271 static int
272 ti_spi_detach(device_t dev)
273 {
274 	struct ti_spi_softc *sc;
275 
276 	sc = device_get_softc(dev);
277 
278 	/* Clear pending interrupts and disable interrupts. */
279 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, 0);
280 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, 0xffff);
281 
282 	/* Reset controller. */
283 	TI_SPI_WRITE(sc, MCSPI_SYSCONFIG, MCSPI_SYSCONFIG_SOFTRESET);
284 
285 	bus_generic_detach(dev);
286 
287 	mtx_destroy(&sc->sc_mtx);
288 	if (sc->sc_intrhand)
289 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
290 	if (sc->sc_irq_res)
291 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
292 	if (sc->sc_mem_res)
293 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
294 
295 	return (0);
296 }
297 
298 static int
299 ti_spi_fill_fifo(struct ti_spi_softc *sc)
300 {
301 	int bytes, timeout;
302 	struct spi_command *cmd;
303 	uint32_t written;
304 	uint8_t *data;
305 
306 	cmd = sc->sc_cmd;
307 	bytes = min(sc->sc_len - sc->sc_written, sc->sc_fifolvl);
308 	while (bytes-- > 0) {
309 		data = (uint8_t *)cmd->tx_cmd;
310 		written = sc->sc_written++;
311 		if (written >= cmd->tx_cmd_sz) {
312 			data = (uint8_t *)cmd->tx_data;
313 			written -= cmd->tx_cmd_sz;
314 		}
315 		if (sc->sc_fifolvl == 1) {
316 			/* FIFO disabled. */
317 			timeout = 1000;
318 			while (--timeout > 0 && (TI_SPI_READ(sc,
319 			    MCSPI_STAT_CH(sc->sc_cs)) & MCSPI_STAT_TXS) == 0) {
320 				DELAY(100);
321 			}
322 			if (timeout == 0)
323 				return (-1);
324 		}
325 		TI_SPI_WRITE(sc, MCSPI_TX_CH(sc->sc_cs), data[written]);
326 	}
327 
328 	return (0);
329 }
330 
331 static int
332 ti_spi_drain_fifo(struct ti_spi_softc *sc)
333 {
334 	int bytes, timeout;
335 	struct spi_command *cmd;
336 	uint32_t read;
337 	uint8_t *data;
338 
339 	cmd = sc->sc_cmd;
340 	bytes = min(sc->sc_len - sc->sc_read, sc->sc_fifolvl);
341 	while (bytes-- > 0) {
342 		data = (uint8_t *)cmd->rx_cmd;
343 		read = sc->sc_read++;
344 		if (read >= cmd->rx_cmd_sz) {
345 			data = (uint8_t *)cmd->rx_data;
346 			read -= cmd->rx_cmd_sz;
347 		}
348 		if (sc->sc_fifolvl == 1) {
349 			/* FIFO disabled. */
350 			timeout = 1000;
351 			while (--timeout > 0 && (TI_SPI_READ(sc,
352 			    MCSPI_STAT_CH(sc->sc_cs)) & MCSPI_STAT_RXS) == 0) {
353 				DELAY(100);
354 			}
355 			if (timeout == 0)
356 				return (-1);
357 		}
358 		data[read] = TI_SPI_READ(sc, MCSPI_RX_CH(sc->sc_cs));
359 	}
360 
361 	return (0);
362 }
363 
364 static void
365 ti_spi_intr(void *arg)
366 {
367 	struct ti_spi_softc *sc;
368 	uint32_t status;
369 
370 	sc = (struct ti_spi_softc *)arg;
371 	TI_SPI_LOCK(sc);
372 	status = TI_SPI_READ(sc, MCSPI_IRQSTATUS);
373 
374 	/*
375 	 * No new TX_empty or RX_full event will be asserted while the CPU has
376 	 * not performed the number of writes or reads defined by
377 	 * MCSPI_XFERLEVEL[AEL] and MCSPI_XFERLEVEL[AFL].  It is responsibility
378 	 * of CPU perform the right number of writes and reads.
379 	 */
380 	if (status & MCSPI_IRQ_TX0_EMPTY)
381 		ti_spi_fill_fifo(sc);
382 	if (status & MCSPI_IRQ_RX0_FULL)
383 		ti_spi_drain_fifo(sc);
384 
385 	/* Clear interrupt status. */
386 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, status);
387 
388 	/* Check for end of transfer. */
389 	if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len) {
390 		sc->sc_flags |= TI_SPI_DONE;
391 		wakeup(sc->sc_dev);
392 	}
393 
394 	TI_SPI_UNLOCK(sc);
395 }
396 
397 static int
398 ti_spi_pio_transfer(struct ti_spi_softc *sc)
399 {
400 
401 	while (sc->sc_len - sc->sc_written > 0) {
402 		if (ti_spi_fill_fifo(sc) == -1)
403 			return (EIO);
404 		if (ti_spi_drain_fifo(sc) == -1)
405 			return (EIO);
406 	}
407 
408 	return (0);
409 }
410 
411 static int
412 ti_spi_gcd(int a, int b)
413 {
414 	int m;
415 
416 	while ((m = a % b) != 0) {
417 		a = b;
418 		b = m;
419 	}
420 
421 	return (b);
422 }
423 
424 static int
425 ti_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
426 {
427 	int err;
428 	struct ti_spi_softc *sc;
429 	uint32_t clockhz, cs, mode, reg;
430 
431 	sc = device_get_softc(dev);
432 
433 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
434 	    ("TX/RX command sizes should be equal"));
435 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
436 	    ("TX/RX data sizes should be equal"));
437 
438 	/* Get the proper chip select for this child. */
439 	spibus_get_cs(child, &cs);
440 	spibus_get_clock(child, &clockhz);
441 	spibus_get_mode(child, &mode);
442 
443 	cs &= ~SPIBUS_CS_HIGH;
444 
445 	if (cs > sc->sc_numcs) {
446 		device_printf(dev, "Invalid chip select %d requested by %s\n",
447 		    cs, device_get_nameunit(child));
448 		return (EINVAL);
449 	}
450 
451 	if (mode > 3)
452 	{
453 	    device_printf(dev, "Invalid mode %d requested by %s\n", mode,
454 		    device_get_nameunit(child));
455 	    return (EINVAL);
456 	}
457 
458 	TI_SPI_LOCK(sc);
459 
460 	/* If the controller is in use wait until it is available. */
461 	while (sc->sc_flags & TI_SPI_BUSY)
462 		mtx_sleep(dev, &sc->sc_mtx, 0, "ti_spi", 0);
463 
464 	/* Now we have control over SPI controller. */
465 	sc->sc_flags = TI_SPI_BUSY;
466 
467 	/* Save the SPI command data. */
468 	sc->sc_cs = cs;
469 	sc->sc_cmd = cmd;
470 	sc->sc_read = 0;
471 	sc->sc_written = 0;
472 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
473 	sc->sc_fifolvl = ti_spi_gcd(sc->sc_len, TI_SPI_FIFOSZ);
474 	if (sc->sc_fifolvl < 2 || sc->sc_len > 0xffff)
475 		sc->sc_fifolvl = 1;	/* FIFO disabled. */
476 	/* Disable FIFO for now. */
477 	sc->sc_fifolvl = 1;
478 
479 	/* Set the bus frequency. */
480 	ti_spi_set_clock(sc, sc->sc_cs, clockhz);
481 
482 	/* Disable the FIFO. */
483 	TI_SPI_WRITE(sc, MCSPI_XFERLEVEL, 0);
484 
485 	/* 8 bits word, d0 miso, d1 mosi, mode 0 and CS active low. */
486 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
487 	reg &= ~(MCSPI_CONF_FFER | MCSPI_CONF_FFEW | MCSPI_CONF_SBPOL |
488 	    MCSPI_CONF_SBE | MCSPI_CONF_TURBO | MCSPI_CONF_IS |
489 	    MCSPI_CONF_DPE1 | MCSPI_CONF_DPE0 | MCSPI_CONF_DMAR |
490 	    MCSPI_CONF_DMAW | MCSPI_CONF_EPOL);
491 	reg |= MCSPI_CONF_DPE0 | MCSPI_CONF_EPOL | MCSPI_CONF_WL8BITS;
492 	reg |= mode; /* POL and PHA are the low bits, we can just OR-in mode */
493 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg);
494 
495 #if 0
496 	/* Enable channel interrupts. */
497 	reg = TI_SPI_READ(sc, MCSPI_IRQENABLE);
498 	reg |= 0xf;
499 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, reg);
500 #endif
501 
502 	/* Start the transfer. */
503 	reg = TI_SPI_READ(sc, MCSPI_CTRL_CH(sc->sc_cs));
504 	TI_SPI_WRITE(sc, MCSPI_CTRL_CH(sc->sc_cs), reg | MCSPI_CTRL_ENABLE);
505 
506 	/* Force CS on. */
507 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
508 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg |= MCSPI_CONF_FORCE);
509 
510 	err = 0;
511 	if (sc->sc_fifolvl == 1)
512 		err = ti_spi_pio_transfer(sc);
513 
514 	/* Force CS off. */
515 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
516 	reg &= ~MCSPI_CONF_FORCE;
517 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg);
518 
519 	/* Disable IRQs. */
520 	reg = TI_SPI_READ(sc, MCSPI_IRQENABLE);
521 	reg &= ~0xf;
522 	TI_SPI_WRITE(sc, MCSPI_IRQENABLE, reg);
523 	TI_SPI_WRITE(sc, MCSPI_IRQSTATUS, 0xf);
524 
525 	/* Disable the SPI channel. */
526 	reg = TI_SPI_READ(sc, MCSPI_CTRL_CH(sc->sc_cs));
527 	reg &= ~MCSPI_CTRL_ENABLE;
528 	TI_SPI_WRITE(sc, MCSPI_CTRL_CH(sc->sc_cs), reg);
529 
530 	/* Disable FIFO. */
531 	reg = TI_SPI_READ(sc, MCSPI_CONF_CH(sc->sc_cs));
532 	reg &= ~(MCSPI_CONF_FFER | MCSPI_CONF_FFEW);
533 	TI_SPI_WRITE(sc, MCSPI_CONF_CH(sc->sc_cs), reg);
534 
535 	/* Release the controller and wakeup the next thread waiting for it. */
536 	sc->sc_flags = 0;
537 	wakeup_one(dev);
538 	TI_SPI_UNLOCK(sc);
539 
540 	return (err);
541 }
542 
543 static phandle_t
544 ti_spi_get_node(device_t bus, device_t dev)
545 {
546 
547 	/* Share controller node with spibus. */
548 	return (ofw_bus_get_node(bus));
549 }
550 
551 static device_method_t ti_spi_methods[] = {
552 	/* Device interface */
553 	DEVMETHOD(device_probe,		ti_spi_probe),
554 	DEVMETHOD(device_attach,	ti_spi_attach),
555 	DEVMETHOD(device_detach,	ti_spi_detach),
556 
557 	/* SPI interface */
558 	DEVMETHOD(spibus_transfer,	ti_spi_transfer),
559 
560 	/* ofw_bus interface */
561 	DEVMETHOD(ofw_bus_get_node,	ti_spi_get_node),
562 
563 	DEVMETHOD_END
564 };
565 
566 static driver_t ti_spi_driver = {
567 	"spi",
568 	ti_spi_methods,
569 	sizeof(struct ti_spi_softc),
570 };
571 
572 DRIVER_MODULE(ti_spi, simplebus, ti_spi_driver, 0, 0);
573 MODULE_DEPEND(ti_spi, ti_sysc, 1, 1, 1);
574