xref: /freebsd/sys/dev/spibus/spigen.c (revision d0b2dbfa) 
1 /*-
2  * Copyright (c) 2015 Brian Fundakowski Feldman.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  */
24 
25 #include <sys/cdefs.h>
26 #include "opt_platform.h"
27 #include "opt_spi.h"
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 #include <sys/conf.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/mman.h>
37 #include <sys/mutex.h>
38 #include <sys/module.h>
39 #include <sys/proc.h>
40 #include <sys/rwlock.h>
41 #include <sys/spigenio.h>
42 #include <sys/types.h>
43 
44 #include <vm/vm.h>
45 #include <vm/vm_extern.h>
46 #include <vm/vm_object.h>
47 #include <vm/vm_page.h>
48 #include <vm/vm_pager.h>
49 
50 #include <dev/spibus/spi.h>
51 #include <dev/spibus/spibusvar.h>
52 
53 #ifdef FDT
54 #include <dev/ofw/ofw_bus_subr.h>
55 
56 static struct ofw_compat_data compat_data[] = {
57 	{"freebsd,spigen", true},
58 	{NULL,             false}
59 };
60 
61 #endif
62 
63 #include "spibus_if.h"
64 
65 struct spigen_softc {
66 	device_t sc_dev;
67 	struct cdev *sc_cdev;
68 #ifdef SPIGEN_LEGACY_CDEVNAME
69 	struct cdev *sc_adev;           /* alias device */
70 #endif
71 	struct mtx sc_mtx;
72 };
73 
74 struct spigen_mmap {
75 	vm_object_t bufobj;
76 	vm_offset_t kvaddr;
77 	size_t      bufsize;
78 };
79 
80 static int
81 spigen_probe(device_t dev)
82 {
83 	int rv;
84 
85 	/*
86 	 * By default we only bid to attach if specifically added by our parent
87 	 * (usually via hint.spigen.#.at=busname).  On FDT systems we bid as the
88 	 * default driver based on being configured in the FDT data.
89 	 */
90 	rv = BUS_PROBE_NOWILDCARD;
91 
92 #ifdef FDT
93 	if (ofw_bus_status_okay(dev) &&
94 	    ofw_bus_search_compatible(dev, compat_data)->ocd_data)
95                 rv = BUS_PROBE_DEFAULT;
96 #endif
97 
98 	device_set_desc(dev, "SPI Generic IO");
99 
100 	return (rv);
101 }
102 
103 static int spigen_open(struct cdev *, int, int, struct thread *);
104 static int spigen_ioctl(struct cdev *, u_long, caddr_t, int, struct thread *);
105 static int spigen_close(struct cdev *, int, int, struct thread *);
106 static d_mmap_single_t spigen_mmap_single;
107 
108 static struct cdevsw spigen_cdevsw = {
109 	.d_version =     D_VERSION,
110 	.d_name =        "spigen",
111 	.d_open =        spigen_open,
112 	.d_ioctl =       spigen_ioctl,
113 	.d_mmap_single = spigen_mmap_single,
114 	.d_close =       spigen_close
115 };
116 
117 static int
118 spigen_attach(device_t dev)
119 {
120 	struct spigen_softc *sc;
121 	const int unit = device_get_unit(dev);
122 	int cs, res;
123 	struct make_dev_args mda;
124 
125 	spibus_get_cs(dev, &cs);
126 	cs &= ~SPIBUS_CS_HIGH; /* trim 'cs high' bit */
127 
128 	sc = device_get_softc(dev);
129 	sc->sc_dev = dev;
130 
131 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
132 
133 	make_dev_args_init(&mda);
134 	mda.mda_flags = MAKEDEV_WAITOK;
135 	mda.mda_devsw = &spigen_cdevsw;
136 	mda.mda_cr = NULL;
137 	mda.mda_uid = UID_ROOT;
138 	mda.mda_gid = GID_OPERATOR;
139 	mda.mda_mode = 0660;
140 	mda.mda_unit = unit;
141 	mda.mda_si_drv1 = dev;
142 
143 	res = make_dev_s(&mda, &(sc->sc_cdev), "spigen%d.%d",
144 	    device_get_unit(device_get_parent(dev)), cs);
145 	if (res) {
146 		return res;
147 	}
148 
149 #ifdef SPIGEN_LEGACY_CDEVNAME
150 	res = make_dev_alias_p(0, &sc->sc_adev, sc->sc_cdev, "spigen%d", unit);
151 	if (res) {
152 		if (sc->sc_cdev) {
153 			destroy_dev(sc->sc_cdev);
154 			sc->sc_cdev = NULL;
155 		}
156 		return res;
157 	}
158 #endif
159 
160 	return (0);
161 }
162 
163 static int
164 spigen_open(struct cdev *cdev, int oflags, int devtype, struct thread *td)
165 {
166 	device_t dev;
167 	struct spigen_softc *sc;
168 
169 	dev = cdev->si_drv1;
170 	sc = device_get_softc(dev);
171 
172 	mtx_lock(&sc->sc_mtx);
173 	device_busy(sc->sc_dev);
174 	mtx_unlock(&sc->sc_mtx);
175 
176 	return (0);
177 }
178 
179 static int
180 spigen_transfer(struct cdev *cdev, struct spigen_transfer *st)
181 {
182 	struct spi_command transfer = SPI_COMMAND_INITIALIZER;
183 	device_t dev = cdev->si_drv1;
184 	int error = 0;
185 
186 #if 0
187 	device_printf(dev, "cmd %p %u data %p %u\n", st->st_command.iov_base,
188 	    st->st_command.iov_len, st->st_data.iov_base, st->st_data.iov_len);
189 #endif
190 
191 	if (st->st_command.iov_len == 0)
192 		return (EINVAL);
193 
194 	transfer.tx_cmd = transfer.rx_cmd = malloc(st->st_command.iov_len,
195 	    M_DEVBUF, M_WAITOK);
196 	if (st->st_data.iov_len > 0) {
197 		transfer.tx_data = transfer.rx_data = malloc(st->st_data.iov_len,
198 		    M_DEVBUF, M_WAITOK);
199 	}
200 	else
201 		transfer.tx_data = transfer.rx_data = NULL;
202 
203 	error = copyin(st->st_command.iov_base, transfer.tx_cmd,
204 	    transfer.tx_cmd_sz = transfer.rx_cmd_sz = st->st_command.iov_len);
205 	if ((error == 0) && (st->st_data.iov_len > 0))
206 		error = copyin(st->st_data.iov_base, transfer.tx_data,
207 		    transfer.tx_data_sz = transfer.rx_data_sz =
208 		                          st->st_data.iov_len);
209 	if (error == 0)
210 		error = SPIBUS_TRANSFER(device_get_parent(dev), dev, &transfer);
211 	if (error == 0) {
212 		error = copyout(transfer.rx_cmd, st->st_command.iov_base,
213 		    transfer.rx_cmd_sz);
214 		if ((error == 0) && (st->st_data.iov_len > 0))
215 			error = copyout(transfer.rx_data, st->st_data.iov_base,
216 			    transfer.rx_data_sz);
217 	}
218 
219 	free(transfer.tx_cmd, M_DEVBUF);
220 	free(transfer.tx_data, M_DEVBUF);
221 	return (error);
222 }
223 
224 static int
225 spigen_transfer_mmapped(struct cdev *cdev, struct spigen_transfer_mmapped *stm)
226 {
227 	struct spi_command transfer = SPI_COMMAND_INITIALIZER;
228 	device_t dev = cdev->si_drv1;
229 	struct spigen_mmap *mmap;
230 	int error;
231 
232 	if ((error = devfs_get_cdevpriv((void **)&mmap)) != 0)
233 		return (error);
234 
235 	if (mmap->bufsize < stm->stm_command_length + stm->stm_data_length)
236 		return (E2BIG);
237 
238 	transfer.tx_cmd = transfer.rx_cmd = (void *)((uintptr_t)mmap->kvaddr);
239 	transfer.tx_cmd_sz = transfer.rx_cmd_sz = stm->stm_command_length;
240 	transfer.tx_data = transfer.rx_data =
241 	    (void *)((uintptr_t)mmap->kvaddr + stm->stm_command_length);
242 	transfer.tx_data_sz = transfer.rx_data_sz = stm->stm_data_length;
243 	error = SPIBUS_TRANSFER(device_get_parent(dev), dev, &transfer);
244 
245 	return (error);
246 }
247 
248 static int
249 spigen_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
250     struct thread *td)
251 {
252 	device_t dev = cdev->si_drv1;
253 	int error;
254 
255 	switch (cmd) {
256 	case SPIGENIOC_TRANSFER:
257 		error = spigen_transfer(cdev, (struct spigen_transfer *)data);
258 		break;
259 	case SPIGENIOC_TRANSFER_MMAPPED:
260 		error = spigen_transfer_mmapped(cdev, (struct spigen_transfer_mmapped *)data);
261 		break;
262 	case SPIGENIOC_GET_CLOCK_SPEED:
263 		error = spibus_get_clock(dev, (uint32_t *)data);
264 		break;
265 	case SPIGENIOC_SET_CLOCK_SPEED:
266 		error = spibus_set_clock(dev, *(uint32_t *)data);
267 		break;
268 	case SPIGENIOC_GET_SPI_MODE:
269 		error = spibus_get_mode(dev, (uint32_t *)data);
270 		break;
271 	case SPIGENIOC_SET_SPI_MODE:
272 		error = spibus_set_mode(dev, *(uint32_t *)data);
273 		break;
274 	default:
275 		error = ENOTTY;
276 		break;
277 	}
278 	return (error);
279 }
280 
281 static void
282 spigen_mmap_cleanup(void *arg)
283 {
284 	struct spigen_mmap *mmap = arg;
285 
286 	if (mmap->kvaddr != 0)
287 		pmap_qremove(mmap->kvaddr, mmap->bufsize / PAGE_SIZE);
288 	if (mmap->bufobj != NULL)
289 		vm_object_deallocate(mmap->bufobj);
290 	free(mmap, M_DEVBUF);
291 }
292 
293 static int
294 spigen_mmap_single(struct cdev *cdev, vm_ooffset_t *offset,
295     vm_size_t size, struct vm_object **object, int nprot)
296 {
297 	struct spigen_mmap *mmap;
298 	vm_page_t *m;
299 	size_t n, pages;
300 	int error;
301 
302 	if (size == 0 ||
303 	    (nprot & (PROT_EXEC | PROT_READ | PROT_WRITE))
304 	    != (PROT_READ | PROT_WRITE))
305 		return (EINVAL);
306 	size = roundup2(size, PAGE_SIZE);
307 	pages = size / PAGE_SIZE;
308 
309 	if (devfs_get_cdevpriv((void **)&mmap) == 0)
310 		return (EBUSY);
311 
312 	mmap = malloc(sizeof(*mmap), M_DEVBUF, M_ZERO | M_WAITOK);
313 	if ((mmap->kvaddr = kva_alloc(size)) == 0) {
314 		spigen_mmap_cleanup(mmap);
315 		return (ENOMEM);
316 	}
317 	mmap->bufsize = size;
318 	mmap->bufobj = vm_pager_allocate(OBJT_PHYS, 0, size, nprot, 0,
319 	    curthread->td_ucred);
320 
321 	m = malloc(sizeof(*m) * pages, M_TEMP, M_WAITOK);
322 	VM_OBJECT_WLOCK(mmap->bufobj);
323 	vm_object_reference_locked(mmap->bufobj); // kernel and userland both
324 	for (n = 0; n < pages; n++) {
325 		m[n] = vm_page_grab(mmap->bufobj, n,
326 		    VM_ALLOC_ZERO | VM_ALLOC_WIRED);
327 		vm_page_valid(m[n]);
328 		vm_page_xunbusy(m[n]);
329 	}
330 	VM_OBJECT_WUNLOCK(mmap->bufobj);
331 	pmap_qenter(mmap->kvaddr, m, pages);
332 	free(m, M_TEMP);
333 
334 	if ((error = devfs_set_cdevpriv(mmap, spigen_mmap_cleanup)) != 0) {
335 		/* Two threads were racing through this code; we lost. */
336 		spigen_mmap_cleanup(mmap);
337 		return (error);
338 	}
339 	*offset = 0;
340 	*object = mmap->bufobj;
341 
342 	return (0);
343 }
344 
345 static int
346 spigen_close(struct cdev *cdev, int fflag, int devtype, struct thread *td)
347 {
348 	device_t dev = cdev->si_drv1;
349 	struct spigen_softc *sc = device_get_softc(dev);
350 
351 	mtx_lock(&sc->sc_mtx);
352 	device_unbusy(sc->sc_dev);
353 	mtx_unlock(&sc->sc_mtx);
354 	return (0);
355 }
356 
357 static int
358 spigen_detach(device_t dev)
359 {
360 	struct spigen_softc *sc;
361 
362 	sc = device_get_softc(dev);
363 
364 #ifdef SPIGEN_LEGACY_CDEVNAME
365 	if (sc->sc_adev)
366 		destroy_dev(sc->sc_adev);
367 #endif
368 
369 	if (sc->sc_cdev)
370 		destroy_dev(sc->sc_cdev);
371 
372 	mtx_destroy(&sc->sc_mtx);
373 
374 	return (0);
375 }
376 
377 static device_method_t spigen_methods[] = {
378 	/* Device interface */
379 	DEVMETHOD(device_probe,		spigen_probe),
380 	DEVMETHOD(device_attach,	spigen_attach),
381 	DEVMETHOD(device_detach,	spigen_detach),
382 	{ 0, 0 }
383 };
384 
385 static driver_t spigen_driver = {
386 	"spigen",
387 	spigen_methods,
388 	sizeof(struct spigen_softc),
389 };
390 
391 DRIVER_MODULE(spigen, spibus, spigen_driver, 0, 0);
392 MODULE_DEPEND(spigen, spibus, 1, 1, 1);
393 #ifdef FDT
394 SIMPLEBUS_PNP_INFO(compat_data);
395 #endif
396