xref: /freebsd/sys/dev/qcom_qup/qcom_spi.c (revision b17b639832e707aab0e9514cf94727498e2d67bd)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2021, Adrian Chadd <adrian@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice unmodified, this list of conditions, and the following
11  *    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 <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 
35 #include <sys/bus.h>
36 #include <sys/interrupt.h>
37 #include <sys/malloc.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <sys/rman.h>
43 #include <sys/gpio.h>
44 
45 #include <vm/vm.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_extern.h>
48 
49 #include <machine/bus.h>
50 #include <machine/cpu.h>
51 
52 #include <dev/fdt/fdt_common.h>
53 #include <dev/fdt/fdt_pinctrl.h>
54 
55 #include <dev/gpio/gpiobusvar.h>
56 #include <dev/ofw/ofw_bus.h>
57 #include <dev/ofw/ofw_bus_subr.h>
58 
59 #include <dev/extres/clk/clk.h>
60 #include <dev/extres/hwreset/hwreset.h>
61 
62 #include <dev/spibus/spi.h>
63 #include <dev/spibus/spibusvar.h>
64 #include "spibus_if.h"
65 
66 #include <dev/qcom_qup/qcom_spi_var.h>
67 #include <dev/qcom_qup/qcom_qup_reg.h>
68 #include <dev/qcom_qup/qcom_spi_reg.h>
69 #include <dev/qcom_qup/qcom_spi_debug.h>
70 
71 static struct ofw_compat_data compat_data[] = {
72 	{ "qcom,spi-qup-v1.1.1",	QCOM_SPI_HW_QPI_V1_1 },
73 	{ "qcom,spi-qup-v2.1.1",	QCOM_SPI_HW_QPI_V2_1 },
74 	{ "qcom,spi-qup-v2.2.1",	QCOM_SPI_HW_QPI_V2_2 },
75 	{ NULL,				0 }
76 };
77 
78 /*
79  * Flip the CS GPIO line either active or inactive.
80  *
81  * Actually listen to the CS polarity.
82  */
83 static void
84 qcom_spi_set_chipsel(struct qcom_spi_softc *sc, int cs, bool active)
85 {
86 	bool pinactive;
87 	bool invert = !! (cs & SPIBUS_CS_HIGH);
88 
89 	cs = cs & ~SPIBUS_CS_HIGH;
90 
91 	if (sc->cs_pins[cs] == NULL) {
92 		device_printf(sc->sc_dev,
93 		    "%s: cs=%u, active=%u, invert=%u, no gpio?\n",
94 		    __func__, cs, active, invert);
95 		return;
96 	}
97 
98 	QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_CHIPSELECT,
99 	    "%s: cs=%u active=%u\n", __func__, cs, active);
100 
101 	/*
102 	 * Default rule here is CS is active low.
103 	 */
104 	if (active)
105 		pinactive = false;
106 	else
107 		pinactive = true;
108 
109 	/*
110 	 * Invert the CS line if required.
111 	 */
112 	if (invert)
113 		pinactive = !! pinactive;
114 
115 	gpio_pin_set_active(sc->cs_pins[cs], pinactive);
116 	gpio_pin_is_active(sc->cs_pins[cs], &pinactive);
117 }
118 
119 static void
120 qcom_spi_intr(void *arg)
121 {
122 	struct qcom_spi_softc *sc = arg;
123 	int ret;
124 
125 	QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_INTR, "%s: called\n", __func__);
126 
127 
128 	QCOM_SPI_LOCK(sc);
129 	ret = qcom_spi_hw_interrupt_handle(sc);
130 	if (ret != 0) {
131 		device_printf(sc->sc_dev,
132 		    "ERROR: failed to read intr status\n");
133 		goto done;
134 	}
135 
136 	/*
137 	 * Handle spurious interrupts outside of an actual
138 	 * transfer.
139 	 */
140 	if (sc->transfer.active == false) {
141 		device_printf(sc->sc_dev,
142 		    "ERROR: spurious interrupt\n");
143 		qcom_spi_hw_ack_opmode(sc);
144 		goto done;
145 	}
146 
147 	/* Now, handle interrupts */
148 	if (sc->intr.error) {
149 		sc->intr.error = false;
150 		device_printf(sc->sc_dev, "ERROR: intr\n");
151 	}
152 
153 	if (sc->intr.do_rx) {
154 		sc->intr.do_rx = false;
155 		QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_INTR,
156 		    "%s: PIO_READ\n", __func__);
157 		if (sc->state.transfer_mode == QUP_IO_M_MODE_FIFO)
158 			ret = qcom_spi_hw_read_pio_fifo(sc);
159 		else
160 			ret = qcom_spi_hw_read_pio_block(sc);
161 		if (ret != 0) {
162 			device_printf(sc->sc_dev,
163 			    "ERROR: qcom_spi_hw_read failed (%u)\n", ret);
164 			goto done;
165 		}
166 	}
167 	if (sc->intr.do_tx) {
168 		sc->intr.do_tx = false;
169 		QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_INTR,
170 		    "%s: PIO_WRITE\n", __func__);
171 		/*
172 		 * For FIFO operations we do not do a write here, we did
173 		 * it at the beginning of the transfer.
174 		 *
175 		 * For BLOCK operations yes, we call the routine.
176 		 */
177 
178 		if (sc->state.transfer_mode == QUP_IO_M_MODE_FIFO)
179 			ret = qcom_spi_hw_ack_write_pio_fifo(sc);
180 		else
181 			ret = qcom_spi_hw_write_pio_block(sc);
182 		if (ret != 0) {
183 			device_printf(sc->sc_dev,
184 			    "ERROR: qcom_spi_hw_write failed (%u)\n", ret);
185 			goto done;
186 		}
187 	}
188 
189 	/*
190 	 * Do this last.  We may actually have completed the
191 	 * transfer in the PIO receive path above and it will
192 	 * set the done flag here.
193 	 */
194 	if (sc->intr.done) {
195 		sc->intr.done = false;
196 		sc->transfer.done = true;
197 		QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_INTR,
198 		    "%s: transfer done\n", __func__);
199 		wakeup(sc);
200 	}
201 
202 done:
203 	QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_INTR,
204 	    "%s: done\n", __func__);
205 	QCOM_SPI_UNLOCK(sc);
206 }
207 
208 static int
209 qcom_spi_probe(device_t dev)
210 {
211 
212 	if (!ofw_bus_status_okay(dev))
213 		return (ENXIO);
214 
215 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
216 		return (ENXIO);
217 
218 	device_set_desc(dev, "Qualcomm SPI Interface");
219 	return (BUS_PROBE_DEFAULT);
220 }
221 
222 /*
223  * Allocate GPIOs if provided in the SPI controller block.
224  *
225  * Some devices will use GPIO lines for chip select.
226  * It's also quite annoying because some devices will want to use
227  * the hardware provided CS gating for say, the first chipselect block,
228  * and then use GPIOs for the later ones.
229  *
230  * So here we just assume for now that SPI index 0 uses the hardware
231  * lines, and >0 use GPIO lines.  Revisit this if better hardware
232  * shows up.
233  *
234  * And finally, iterating over the cs-gpios list to allocate GPIOs
235  * doesn't actually tell us what the polarity is.  For that we need
236  * to actually iterate over the list of child nodes and check what
237  * their properties are (and look for "spi-cs-high".)
238  */
239 static void
240 qcom_spi_attach_gpios(struct qcom_spi_softc *sc)
241 {
242 	phandle_t node;
243 	int idx, err;
244 
245 	/* Allocate gpio pins for configured chip selects. */
246 	node = ofw_bus_get_node(sc->sc_dev);
247 	for (idx = 0; idx < nitems(sc->cs_pins); idx++) {
248 		err = gpio_pin_get_by_ofw_propidx(sc->sc_dev, node,
249 		    "cs-gpios", idx, &sc->cs_pins[idx]);
250 		if (err == 0) {
251 			err = gpio_pin_setflags(sc->cs_pins[idx],
252 			    GPIO_PIN_OUTPUT);
253 			if (err != 0) {
254 				device_printf(sc->sc_dev,
255 				    "error configuring gpio for"
256 				    " cs %u (%d)\n", idx, err);
257 			}
258 			/*
259 			 * We can't set this HIGH right now because
260 			 * we don't know if it needs to be set to
261 			 * high for inactive or low for inactive
262 			 * based on the child SPI device flags.
263 			 */
264 #if 0
265 			gpio_pin_set_active(sc->cs_pins[idx], 1);
266 			gpio_pin_is_active(sc->cs_pins[idx], &tmp);
267 #endif
268 		} else {
269 			device_printf(sc->sc_dev,
270 			    "cannot configure gpio for chip select %u\n", idx);
271 			sc->cs_pins[idx] = NULL;
272 		}
273 	}
274 }
275 
276 static void
277 qcom_spi_sysctl_attach(struct qcom_spi_softc *sc)
278 {
279 	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->sc_dev);
280 	struct sysctl_oid *tree = device_get_sysctl_tree(sc->sc_dev);
281 
282 	SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
283 	    "debug", CTLFLAG_RW, &sc->sc_debug, 0,
284 	    "control debugging printfs");
285 }
286 
287 static int
288 qcom_spi_attach(device_t dev)
289 {
290 	struct qcom_spi_softc *sc = device_get_softc(dev);
291 	int rid, ret, i, val;
292 
293 	sc->sc_dev = dev;
294 
295 	/*
296 	 * Hardware version is stored in the ofw_compat_data table.
297 	 */
298 	sc->hw_version =
299 	    ofw_bus_search_compatible(dev, compat_data)->ocd_data;
300 
301 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
302 
303 	rid = 0;
304 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
305 	    RF_ACTIVE);
306 	if (!sc->sc_mem_res) {
307 		device_printf(dev, "ERROR: Could not map memory\n");
308 		ret = ENXIO;
309 		goto error;
310 	}
311 
312 	rid = 0;
313 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
314 	    RF_ACTIVE | RF_SHAREABLE);
315 	if (!sc->sc_irq_res) {
316 		device_printf(dev, "ERROR: Could not map interrupt\n");
317 		ret = ENXIO;
318 		goto error;
319 	}
320 
321 	ret = bus_setup_intr(dev, sc->sc_irq_res,
322 	    INTR_TYPE_MISC | INTR_MPSAFE,
323 	    NULL, qcom_spi_intr, sc, &sc->sc_irq_h);
324 	if (ret != 0) {
325 		device_printf(dev, "ERROR: could not configure interrupt "
326 		    "(%d)\n",
327 		    ret);
328 		goto error;
329 	}
330 
331 	qcom_spi_attach_gpios(sc);
332 
333 	ret = clk_get_by_ofw_name(dev, 0, "core", &sc->clk_core);
334 	if (ret != 0) {
335 		device_printf(dev, "ERROR: could not get %s clock (%d)\n",
336 		    "core", ret);
337 		goto error;
338 	}
339 	ret = clk_get_by_ofw_name(dev, 0, "iface", &sc->clk_iface);
340 	if (ret != 0) {
341 		device_printf(dev, "ERROR: could not get %s clock (%d)\n",
342 		    "iface", ret);
343 		goto error;
344 	}
345 
346 	/* Bring up initial clocks if they're off */
347 	ret = clk_enable(sc->clk_core);
348 	if (ret != 0) {
349 		device_printf(dev, "ERROR: couldn't enable core clock (%u)\n",
350 		    ret);
351 		goto error;
352 	}
353 	ret = clk_enable(sc->clk_iface);
354 	if (ret != 0) {
355 		device_printf(dev, "ERROR: couldn't enable iface clock (%u)\n",
356 		    ret);
357 		goto error;
358 	}
359 
360 	/*
361 	 * Read optional spi-max-frequency
362 	 */
363 	if (OF_getencprop(ofw_bus_get_node(dev), "spi-max-frequency",
364 	    &val, sizeof(val)) > 0)
365 		sc->config.max_frequency = val;
366 	else
367 		sc->config.max_frequency = SPI_MAX_RATE;
368 
369 	/*
370 	 * Read optional cs-select
371 	 */
372 	if (OF_getencprop(ofw_bus_get_node(dev), "cs-select",
373 	    &val, sizeof(val)) > 0)
374 		sc->config.cs_select = val;
375 	else
376 		sc->config.cs_select = 0;
377 
378 	/*
379 	 * Read optional num-cs
380 	 */
381 	if (OF_getencprop(ofw_bus_get_node(dev), "num-cs",
382 	    &val, sizeof(val)) > 0)
383 		sc->config.num_cs = val;
384 	else
385 		sc->config.num_cs = SPI_NUM_CHIPSELECTS;
386 
387 	ret = fdt_pinctrl_configure_by_name(dev, "default");
388 	if (ret != 0) {
389 		device_printf(dev,
390 		    "ERROR: could not configure default pinmux\n");
391 		goto error;
392 	}
393 
394 	ret = qcom_spi_hw_read_controller_transfer_sizes(sc);
395 	if (ret != 0) {
396 		device_printf(dev, "ERROR: Could not read transfer config\n");
397 		goto error;
398 	}
399 
400 
401 	device_printf(dev, "BLOCK: input=%u bytes, output=%u bytes\n",
402 	    sc->config.input_block_size,
403 	    sc->config.output_block_size);
404 	device_printf(dev, "FIFO: input=%u bytes, output=%u bytes\n",
405 	    sc->config.input_fifo_size,
406 	    sc->config.output_fifo_size);
407 
408 	/* QUP config */
409 	QCOM_SPI_LOCK(sc);
410 	ret = qcom_spi_hw_qup_init_locked(sc);
411 	if (ret != 0) {
412 		device_printf(dev, "ERROR: QUP init failed (%d)\n", ret);
413 		QCOM_SPI_UNLOCK(sc);
414 		goto error;
415 	}
416 
417 	/* Initial SPI config */
418 	ret = qcom_spi_hw_spi_init_locked(sc);
419 	if (ret != 0) {
420 		device_printf(dev, "ERROR: SPI init failed (%d)\n", ret);
421 		QCOM_SPI_UNLOCK(sc);
422 		goto error;
423 	}
424 	QCOM_SPI_UNLOCK(sc);
425 
426 	sc->spibus = device_add_child(dev, "spibus", -1);
427 
428 	/* We're done, so shut down the interface clock for now */
429 	device_printf(dev, "DONE: shutting down interface clock for now\n");
430 	clk_disable(sc->clk_iface);
431 
432 	/* Register for debug sysctl */
433 	qcom_spi_sysctl_attach(sc);
434 
435 	return (bus_generic_attach(dev));
436 error:
437 	if (sc->sc_irq_h)
438 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_irq_h);
439 	if (sc->sc_mem_res)
440 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
441 	if (sc->sc_irq_res)
442 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
443 	if (sc->clk_core) {
444 		clk_disable(sc->clk_core);
445 		clk_release(sc->clk_core);
446 	}
447 	if (sc->clk_iface) {
448 		clk_disable(sc->clk_iface);
449 		clk_release(sc->clk_iface);
450 	}
451 	for (i = 0; i < CS_MAX; i++) {
452 		if (sc->cs_pins[i] != NULL)
453 			gpio_pin_release(sc->cs_pins[i]);
454 	}
455 	mtx_destroy(&sc->sc_mtx);
456 	return (ret);
457 }
458 
459 /*
460  * Do a PIO transfer.
461  *
462  * Note that right now the TX/RX lens need to match, I'm not doing
463  * dummy reads / dummy writes as required if they're not the same
464  * size.  The QUP hardware supports doing multi-phase transactions
465  * where the FIFO isn't engaged for transmit or receive, but it's
466  * not yet being done here.
467  */
468 static int
469 qcom_spi_transfer_pio_block(struct qcom_spi_softc *sc, int mode,
470     char *tx_buf, int tx_len, char *rx_buf, int rx_len)
471 {
472 	int ret = 0;
473 
474 	QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_TRANSFER, "%s: start\n",
475 	    __func__);
476 
477 	if (rx_len != tx_len) {
478 		device_printf(sc->sc_dev,
479 		    "ERROR: tx/rx len doesn't match (%d/%d)\n",
480 		    tx_len, rx_len);
481 		return (ENXIO);
482 	}
483 
484 	QCOM_SPI_ASSERT_LOCKED(sc);
485 
486 	/*
487 	 * Make initial choices for transfer configuration.
488 	 */
489 	ret = qcom_spi_hw_setup_transfer_selection(sc, tx_len);
490 	if (ret != 0) {
491 		device_printf(sc->sc_dev,
492 		    "ERROR: failed to setup transfer selection (%d)\n",
493 		    ret);
494 		return (ret);
495 	}
496 
497 	/* Now set suitable buffer/lengths */
498 	sc->transfer.tx_buf = tx_buf;
499 	sc->transfer.tx_len = tx_len;
500 	sc->transfer.rx_buf = rx_buf;
501 	sc->transfer.rx_len = rx_len;
502 	sc->transfer.done = false;
503 	sc->transfer.active = false;
504 
505 	/*
506 	 * Loop until the full transfer set is done.
507 	 *
508 	 * qcom_spi_hw_setup_current_transfer() will take care of
509 	 * setting a maximum transfer size for the hardware and choose
510 	 * a suitable operating mode.
511 	 */
512 	while (sc->transfer.tx_offset < sc->transfer.tx_len) {
513 		/*
514 		 * Set transfer to false early; this covers
515 		 * it also finishing a sub-transfer and we're
516 		 * about the put the block into RESET state before
517 		 * starting a new transfer.
518 		 */
519 		sc->transfer.active = false;
520 
521 		QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_TRANSFER,
522 		    "%s: tx=%d of %d bytes, rx=%d of %d bytes\n",
523 		    __func__,
524 		    sc->transfer.tx_offset, sc->transfer.tx_len,
525 		    sc->transfer.rx_offset, sc->transfer.rx_len);
526 
527 		/*
528 		 * Set state to RESET before doing anything.
529 		 *
530 		 * Otherwise the second sub-transfer that we queue up
531 		 * will generate interrupts immediately when we start
532 		 * configuring it here and it'll start underflowing.
533 		 */
534 		ret = qcom_spi_hw_qup_set_state_locked(sc, QUP_STATE_RESET);
535 		if (ret != 0) {
536 			device_printf(sc->sc_dev,
537 			    "ERROR: can't transition to RESET (%u)\n", ret);
538 			goto done;
539 		}
540 		/* blank interrupt state; we'll do a RESET below */
541 		bzero(&sc->intr, sizeof(sc->intr));
542 		sc->transfer.done = false;
543 
544 		/*
545 		 * Configure what the transfer configuration for this
546 		 * sub-transfer will be.
547 		 */
548 		ret = qcom_spi_hw_setup_current_transfer(sc);
549 		if (ret != 0) {
550 			device_printf(sc->sc_dev,
551 			    "ERROR: failed to setup sub transfer (%d)\n",
552 			    ret);
553 			goto done;
554 		}
555 
556 		/*
557 		 * For now since we're configuring up PIO, we only setup
558 		 * the PIO transfer size.
559 		 */
560 		ret = qcom_spi_hw_setup_pio_transfer_cnt(sc);
561 		if (ret != 0) {
562 			device_printf(sc->sc_dev,
563 			    "ERROR: qcom_spi_hw_setup_pio_transfer_cnt failed"
564 			    " (%u)\n", ret);
565 			goto done;
566 		}
567 
568 #if 0
569 		/*
570 		 * This is what we'd do to setup the block transfer sizes.
571 		 */
572 		ret = qcom_spi_hw_setup_block_transfer_cnt(sc);
573 		if (ret != 0) {
574 			device_printf(sc->sc_dev,
575 			    "ERROR: qcom_spi_hw_setup_block_transfer_cnt failed"
576 			    " (%u)\n", ret);
577 			goto done;
578 		}
579 #endif
580 
581 		ret = qcom_spi_hw_setup_io_modes(sc);
582 		if (ret != 0) {
583 			device_printf(sc->sc_dev,
584 			    "ERROR: qcom_spi_hw_setup_io_modes failed"
585 			    " (%u)\n", ret);
586 			goto done;
587 		}
588 
589 		ret = qcom_spi_hw_setup_spi_io_clock_polarity(sc,
590 		    !! (mode & SPIBUS_MODE_CPOL));
591 		if (ret != 0) {
592 			device_printf(sc->sc_dev,
593 			    "ERROR: qcom_spi_hw_setup_spi_io_clock_polarity"
594 			    "    failed (%u)\n", ret);
595 			goto done;
596 		}
597 
598 		ret = qcom_spi_hw_setup_spi_config(sc, sc->state.frequency,
599 		    !! (mode & SPIBUS_MODE_CPHA));
600 		if (ret != 0) {
601 			device_printf(sc->sc_dev,
602 			    "ERROR: qcom_spi_hw_setup_spi_config failed"
603 			    " (%u)\n", ret);
604 			goto done;
605 		}
606 
607 		ret = qcom_spi_hw_setup_qup_config(sc, !! (tx_len > 0),
608 		    !! (rx_len > 0));
609 		if (ret != 0) {
610 			device_printf(sc->sc_dev,
611 			    "ERROR: qcom_spi_hw_setup_qup_config failed"
612 			    " (%u)\n", ret);
613 			goto done;
614 		}
615 
616 		ret = qcom_spi_hw_setup_operational_mask(sc);
617 		if (ret != 0) {
618 			device_printf(sc->sc_dev,
619 			    "ERROR: qcom_spi_hw_setup_operational_mask failed"
620 			    " (%u)\n", ret);
621 			goto done;
622 		}
623 
624 		/*
625 		 * Setup is done; reset the controller and start the PIO
626 		 * write.
627 		 */
628 
629 		/*
630 		 * Set state to RUN; we may start getting interrupts that
631 		 * are valid and we need to handle.
632 		 */
633 		sc->transfer.active = true;
634 		ret = qcom_spi_hw_qup_set_state_locked(sc, QUP_STATE_RUN);
635 		if (ret != 0) {
636 			device_printf(sc->sc_dev,
637 			    "ERROR: can't transition to RUN (%u)\n", ret);
638 			goto done;
639 		}
640 
641 		/*
642 		 * Set state to PAUSE
643 		 */
644 		ret = qcom_spi_hw_qup_set_state_locked(sc, QUP_STATE_PAUSE);
645 		if (ret != 0) {
646 			device_printf(sc->sc_dev,
647 			    "ERROR: can't transition to PAUSE (%u)\n", ret);
648 			goto done;
649 		}
650 
651 		/*
652 		 * If FIFO mode, write data now.  Else, we'll get an
653 		 * interrupt when it's time to populate more data
654 		 * in BLOCK mode.
655 		 */
656 		if (sc->state.transfer_mode == QUP_IO_M_MODE_FIFO)
657 			ret = qcom_spi_hw_write_pio_fifo(sc);
658 		else
659 			ret = qcom_spi_hw_write_pio_block(sc);
660 		if (ret != 0) {
661 			device_printf(sc->sc_dev,
662 			    "ERROR: qcom_spi_hw_write failed (%u)\n", ret);
663 			goto done;
664 		}
665 
666 		/*
667 		 * Set state to RUN
668 		 */
669 		ret = qcom_spi_hw_qup_set_state_locked(sc, QUP_STATE_RUN);
670 		if (ret != 0) {
671 			device_printf(sc->sc_dev,
672 			    "ERROR: can't transition to RUN (%u)\n", ret);
673 			goto done;
674 		}
675 
676 		/*
677 		 * Wait for an interrupt notification (which will
678 		 * continue to drive the state machine for this
679 		 * sub-transfer) or timeout.
680 		 */
681 		ret = 0;
682 		while (ret == 0 && sc->transfer.done == false) {
683 			QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_TRANSFER,
684 			    "%s: waiting\n", __func__);
685 			ret = msleep(sc, &sc->sc_mtx, 0, "qcom_spi", 0);
686 		}
687 	}
688 done:
689 	/*
690 	 * Complete; put controller into reset.
691 	 *
692 	 * Don't worry about return value here; if we errored out above then
693 	 * we want to communicate that value to the caller.
694 	 */
695 	(void) qcom_spi_hw_qup_set_state_locked(sc, QUP_STATE_RESET);
696 	QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_TRANSFER,
697 	    "%s: completed\n", __func__);
698 
699 	 /*
700 	  * Blank the transfer state so we don't use an old transfer
701 	  * state in a subsequent interrupt.
702 	  */
703 	(void) qcom_spi_hw_complete_transfer(sc);
704 	sc->transfer.active = false;
705 
706 	return (ret);
707 }
708 
709 static int
710 qcom_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
711 {
712 	struct qcom_spi_softc *sc = device_get_softc(dev);
713 	uint32_t cs_val, mode_val, clock_val;
714 	uint32_t ret = 0;
715 
716 	spibus_get_cs(child, &cs_val);
717 	spibus_get_clock(child, &clock_val);
718 	spibus_get_mode(child, &mode_val);
719 
720 	QCOM_SPI_DPRINTF(sc, QCOM_SPI_DEBUG_TRANSFER,
721 	    "%s: called; child cs=0x%08x, clock=%u, mode=0x%08x, "
722 	    "cmd=%u/%u bytes; data=%u/%u bytes\n",
723 	    __func__,
724 	    cs_val,
725 	    clock_val,
726 	    mode_val,
727 	    cmd->tx_cmd_sz, cmd->rx_cmd_sz,
728 	    cmd->tx_data_sz, cmd->rx_data_sz);
729 
730 	QCOM_SPI_LOCK(sc);
731 
732 	/*
733 	 * wait until the controller isn't busy
734 	 */
735 	while (sc->sc_busy == true)
736 		mtx_sleep(sc, &sc->sc_mtx, 0, "qcom_spi_wait", 0);
737 
738 	/*
739 	 * it's ours now!
740 	 */
741 	sc->sc_busy = true;
742 
743 	sc->state.cs_high = !! (cs_val & SPIBUS_CS_HIGH);
744 	sc->state.frequency = clock_val;
745 
746 	/*
747 	 * We can't set the clock frequency and enable it
748 	 * with the driver lock held, as the SPI lock is non-sleepable
749 	 * and the clock framework is sleepable.
750 	 *
751 	 * No other transaction is going on right now, so we can
752 	 * unlock here and do the clock related work.
753 	 */
754 	QCOM_SPI_UNLOCK(sc);
755 
756 	/*
757 	 * Set the clock frequency
758 	 */
759 	ret = clk_set_freq(sc->clk_iface, sc->state.frequency, 0);
760 	if (ret != 0) {
761 		device_printf(sc->sc_dev,
762 		    "ERROR: failed to set frequency to %u\n",
763 		    sc->state.frequency);
764 		goto done2;
765 	}
766 	clk_enable(sc->clk_iface);
767 
768 	QCOM_SPI_LOCK(sc);
769 
770 	/*
771 	 * Set state to RESET
772 	 */
773 	ret = qcom_spi_hw_qup_set_state_locked(sc, QUP_STATE_RESET);
774 	if (ret != 0) {
775 		device_printf(sc->sc_dev,
776 		    "ERROR: can't transition to RESET (%u)\n", ret);
777 		goto done;
778 	}
779 
780 	/* Assert hardware CS if set, else GPIO */
781 	if (sc->cs_pins[cs_val & ~SPIBUS_CS_HIGH] == NULL)
782 		qcom_spi_hw_spi_cs_force(sc, cs_val & SPIBUS_CS_HIGH, true);
783 	else
784 		qcom_spi_set_chipsel(sc, cs_val & ~SPIBUS_CS_HIGH, true);
785 
786 	/*
787 	 * cmd buffer transfer
788 	 */
789 	ret = qcom_spi_transfer_pio_block(sc, mode_val, cmd->tx_cmd,
790 	    cmd->tx_cmd_sz, cmd->rx_cmd, cmd->rx_cmd_sz);
791 	if (ret != 0) {
792 		device_printf(sc->sc_dev,
793 		    "ERROR: failed to transfer cmd payload (%u)\n", ret);
794 		goto done;
795 	}
796 
797 	/*
798 	 * data buffer transfer
799 	 */
800 	if (cmd->tx_data_sz > 0) {
801 		ret = qcom_spi_transfer_pio_block(sc, mode_val, cmd->tx_data,
802 		    cmd->tx_data_sz, cmd->rx_data, cmd->rx_data_sz);
803 		if (ret != 0) {
804 			device_printf(sc->sc_dev,
805 			    "ERROR: failed to transfer data payload (%u)\n",
806 			    ret);
807 			goto done;
808 		}
809 	}
810 
811 done:
812 	/* De-assert GPIO/CS */
813 	if (sc->cs_pins[cs_val & ~SPIBUS_CS_HIGH] == NULL)
814 		qcom_spi_hw_spi_cs_force(sc, cs_val & ~SPIBUS_CS_HIGH, false);
815 	else
816 		qcom_spi_set_chipsel(sc, cs_val & ~SPIBUS_CS_HIGH, false);
817 
818 	/*
819 	 * Similarly to when we enabled the clock, we can't hold it here
820 	 * across a clk API as that's a sleep lock and we're non-sleepable.
821 	 * So instead we unlock/relock here, but we still hold the busy flag.
822 	 */
823 
824 	QCOM_SPI_UNLOCK(sc);
825 	clk_disable(sc->clk_iface);
826 	QCOM_SPI_LOCK(sc);
827 done2:
828 	/*
829 	 * We're done; so mark the bus as not busy and wakeup
830 	 * the next caller.
831 	 */
832 	sc->sc_busy = false;
833 	wakeup_one(sc);
834 	QCOM_SPI_UNLOCK(sc);
835 	return (ret);
836 }
837 
838 static int
839 qcom_spi_detach(device_t dev)
840 {
841 	struct qcom_spi_softc *sc = device_get_softc(dev);
842 	int i;
843 
844 	bus_generic_detach(sc->sc_dev);
845 	if (sc->spibus != NULL)
846 		device_delete_child(dev, sc->spibus);
847 
848 	if (sc->sc_irq_h)
849 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_irq_h);
850 
851 	if (sc->clk_iface) {
852 		clk_disable(sc->clk_iface);
853 		clk_release(sc->clk_iface);
854 	}
855 	if (sc->clk_core) {
856 		clk_disable(sc->clk_core);
857 		clk_release(sc->clk_core);
858 	}
859 
860 	for (i = 0; i < CS_MAX; i++) {
861 		if (sc->cs_pins[i] != NULL)
862 			gpio_pin_release(sc->cs_pins[i]);
863 	}
864 
865 	if (sc->sc_mem_res)
866 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
867 	if (sc->sc_irq_res)
868 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
869 
870 	mtx_destroy(&sc->sc_mtx);
871 
872 	return (0);
873 }
874 
875 static phandle_t
876 qcom_spi_get_node(device_t bus, device_t dev)
877 {
878 
879 	return ofw_bus_get_node(bus);
880 }
881 
882 
883 static device_method_t qcom_spi_methods[] = {
884 	/* Device interface */
885 	DEVMETHOD(device_probe,		qcom_spi_probe),
886 	DEVMETHOD(device_attach,	qcom_spi_attach),
887 	DEVMETHOD(device_detach,	qcom_spi_detach),
888 	/* TODO: suspend */
889 	/* TODO: resume */
890 
891 	DEVMETHOD(spibus_transfer,	qcom_spi_transfer),
892 
893 	/* ofw_bus_if */
894 	DEVMETHOD(ofw_bus_get_node,     qcom_spi_get_node),
895 
896 	DEVMETHOD_END
897 };
898 
899 static driver_t qcom_spi_driver = {
900 	"qcom_spi",
901 	qcom_spi_methods,
902 	sizeof(struct qcom_spi_softc),
903 };
904 
905 DRIVER_MODULE(qcom_spi, simplebus, qcom_spi_driver, 0, 0);
906 DRIVER_MODULE(ofw_spibus, qcom_spi, ofw_spibus_driver, 0, 0);
907 MODULE_DEPEND(qcom_spi, ofw_spibus, 1, 1, 1);
908 SIMPLEBUS_PNP_INFO(compat_data);
909