xref: /freebsd/sys/dev/spibus/spigen.c (revision 32d74127)
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 __FBSDID("$FreeBSD$");
27 
28 #include "opt_platform.h"
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/mman.h>
38 #include <sys/mutex.h>
39 #include <sys/module.h>
40 #include <sys/proc.h>
41 #include <sys/rwlock.h>
42 #include <sys/spigenio.h>
43 #include <sys/sysctl.h>
44 #include <sys/types.h>
45 
46 #include <vm/vm.h>
47 #include <vm/vm_extern.h>
48 #include <vm/vm_object.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_pager.h>
51 
52 #include <dev/spibus/spi.h>
53 
54 #include "spibus_if.h"
55 
56 struct spigen_softc {
57 	device_t sc_dev;
58 	struct cdev *sc_cdev;
59 	struct mtx sc_mtx;
60 	uint32_t sc_clock_speed;
61 	uint32_t sc_command_length_max; /* cannot change while mmapped */
62 	uint32_t sc_data_length_max;    /* cannot change while mmapped */
63 	vm_object_t sc_mmap_buffer;     /* command, then data */
64 	vm_offset_t sc_mmap_kvaddr;
65 	size_t sc_mmap_buffer_size;
66 	int sc_mmap_busy;
67 	int sc_debug;
68 };
69 
70 #ifdef FDT
71 static void
72 spigen_identify(driver_t *driver, device_t parent)
73 {
74 	if (device_find_child(parent, "spigen", -1) != NULL)
75 		return;
76 	if (BUS_ADD_CHILD(parent, 0, "spigen", -1) == NULL)
77 		device_printf(parent, "add child failed\n");
78 }
79 #endif
80 
81 static int
82 spigen_probe(device_t dev)
83 {
84 
85 	device_set_desc(dev, "SPI Generic IO");
86 
87 	return (BUS_PROBE_NOWILDCARD);
88 }
89 
90 static int spigen_open(struct cdev *, int, int, struct thread *);
91 static int spigen_ioctl(struct cdev *, u_long, caddr_t, int, struct thread *);
92 static int spigen_close(struct cdev *, int, int, struct thread *);
93 static d_mmap_single_t spigen_mmap_single;
94 
95 static struct cdevsw spigen_cdevsw = {
96 	.d_version =     D_VERSION,
97 	.d_name =        "spigen",
98 	.d_open =        spigen_open,
99 	.d_ioctl =       spigen_ioctl,
100 	.d_mmap_single = spigen_mmap_single,
101 	.d_close =       spigen_close
102 };
103 
104 static int
105 spigen_command_length_max_proc(SYSCTL_HANDLER_ARGS)
106 {
107 	struct spigen_softc *sc = (struct spigen_softc *)arg1;
108 	uint32_t command_length_max;
109 	int error;
110 
111 	mtx_lock(&sc->sc_mtx);
112 	command_length_max = sc->sc_command_length_max;
113 	mtx_unlock(&sc->sc_mtx);
114 	error = sysctl_handle_int(oidp, &command_length_max,
115 	    sizeof(command_length_max), req);
116 	if (error == 0 && req->newptr != NULL) {
117 		mtx_lock(&sc->sc_mtx);
118 		if (sc->sc_mmap_buffer != NULL)
119 			error = EBUSY;
120 		else
121 			sc->sc_command_length_max = command_length_max;
122 		mtx_unlock(&sc->sc_mtx);
123 	}
124 	return (error);
125 }
126 
127 static int
128 spigen_data_length_max_proc(SYSCTL_HANDLER_ARGS)
129 {
130 	struct spigen_softc *sc = (struct spigen_softc *)arg1;
131 	uint32_t data_length_max;
132 	int error;
133 
134 	mtx_lock(&sc->sc_mtx);
135 	data_length_max = sc->sc_data_length_max;
136 	mtx_unlock(&sc->sc_mtx);
137 	error = sysctl_handle_int(oidp, &data_length_max,
138 	    sizeof(data_length_max), req);
139 	if (error == 0 && req->newptr != NULL) {
140 		mtx_lock(&sc->sc_mtx);
141 		if (sc->sc_mmap_buffer != NULL)
142 			error = EBUSY;
143 		else
144 			sc->sc_data_length_max = data_length_max;
145 		mtx_unlock(&sc->sc_mtx);
146 	}
147 	return (error);
148 }
149 
150 static void
151 spigen_sysctl_init(struct spigen_softc *sc)
152 {
153 	struct sysctl_ctx_list *ctx;
154 	struct sysctl_oid *tree_node;
155 	struct sysctl_oid_list *tree;
156 
157 	/*
158 	 * Add system sysctl tree/handlers.
159 	 */
160 	ctx = device_get_sysctl_ctx(sc->sc_dev);
161 	tree_node = device_get_sysctl_tree(sc->sc_dev);
162 	tree = SYSCTL_CHILDREN(tree_node);
163 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "command_length_max",
164 	    CTLFLAG_MPSAFE | CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
165 	    spigen_command_length_max_proc, "IU", "SPI command header portion (octets)");
166 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "data_length_max",
167 	    CTLFLAG_MPSAFE | CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
168 	    spigen_data_length_max_proc, "IU", "SPI data trailer portion (octets)");
169 	SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "data", CTLFLAG_RW,
170 	    &sc->sc_debug, 0, "debug flags");
171 
172 }
173 
174 static int
175 spigen_attach(device_t dev)
176 {
177 	struct spigen_softc *sc;
178 	const int unit = device_get_unit(dev);
179 
180 	sc = device_get_softc(dev);
181 	sc->sc_dev = dev;
182 	sc->sc_cdev = make_dev(&spigen_cdevsw, unit,
183 	    UID_ROOT, GID_OPERATOR, 0660, "spigen%d", unit);
184 	sc->sc_cdev->si_drv1 = dev;
185 	sc->sc_command_length_max = PAGE_SIZE;
186 	sc->sc_data_length_max = PAGE_SIZE;
187 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
188 	spigen_sysctl_init(sc);
189 
190 	return (0);
191 }
192 
193 static int
194 spigen_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
195 {
196 
197 	return (0);
198 }
199 
200 static int
201 spigen_transfer(struct cdev *cdev, struct spigen_transfer *st)
202 {
203 	struct spi_command transfer = SPI_COMMAND_INITIALIZER;
204 	device_t dev = cdev->si_drv1;
205 	struct spigen_softc *sc = device_get_softc(dev);
206 	int error = 0;
207 
208 	mtx_lock(&sc->sc_mtx);
209 	if (st->st_command.iov_len == 0)
210 		error = EINVAL;
211 	else if (st->st_command.iov_len > sc->sc_command_length_max ||
212 	    st->st_data.iov_len > sc->sc_data_length_max)
213 		error = ENOMEM;
214 	mtx_unlock(&sc->sc_mtx);
215 	if (error)
216 		return (error);
217 
218 #if 0
219 	device_printf(dev, "cmd %p %u data %p %u\n", st->st_command.iov_base,
220 	    st->st_command.iov_len, st->st_data.iov_base, st->st_data.iov_len);
221 #endif
222 	transfer.tx_cmd = transfer.rx_cmd = malloc(st->st_command.iov_len,
223 	    M_DEVBUF, M_WAITOK);
224 	if (transfer.tx_cmd == NULL)
225 		return (ENOMEM);
226 	if (st->st_data.iov_len > 0) {
227 		transfer.tx_data = transfer.rx_data = malloc(st->st_data.iov_len,
228 		    M_DEVBUF, M_WAITOK);
229 		if (transfer.tx_data == NULL) {
230 			free(transfer.tx_cmd, M_DEVBUF);
231 			return (ENOMEM);
232 		}
233 	}
234 	else
235 		transfer.tx_data = transfer.rx_data = NULL;
236 
237 	error = copyin(st->st_command.iov_base, transfer.tx_cmd,
238 	    transfer.tx_cmd_sz = transfer.rx_cmd_sz = st->st_command.iov_len);
239 	if ((error == 0) && (st->st_data.iov_len > 0))
240 		error = copyin(st->st_data.iov_base, transfer.tx_data,
241 		    transfer.tx_data_sz = transfer.rx_data_sz =
242 		                          st->st_data.iov_len);
243 	if (error == 0)
244 		error = SPIBUS_TRANSFER(device_get_parent(dev), dev, &transfer);
245 	if (error == 0) {
246 		error = copyout(transfer.rx_cmd, st->st_command.iov_base,
247 		    transfer.rx_cmd_sz);
248 		if ((error == 0) && (st->st_data.iov_len > 0))
249 			error = copyout(transfer.rx_data, st->st_data.iov_base,
250 			    transfer.rx_data_sz);
251 	}
252 
253 	free(transfer.tx_cmd, M_DEVBUF);
254 	free(transfer.tx_data, M_DEVBUF);
255 	return (error);
256 }
257 
258 static int
259 spigen_transfer_mmapped(struct cdev *cdev, struct spigen_transfer_mmapped *stm)
260 {
261 	struct spi_command transfer = SPI_COMMAND_INITIALIZER;
262 	device_t dev = cdev->si_drv1;
263 	struct spigen_softc *sc = device_get_softc(dev);
264 	int error = 0;
265 
266 	mtx_lock(&sc->sc_mtx);
267 	if (sc->sc_mmap_busy)
268 		error = EBUSY;
269 	else if (stm->stm_command_length > sc->sc_command_length_max ||
270 	    stm->stm_data_length > sc->sc_data_length_max)
271 		error = E2BIG;
272 	else if (sc->sc_mmap_buffer == NULL)
273 		error = EINVAL;
274 	else if (sc->sc_mmap_buffer_size <
275 	    stm->stm_command_length + stm->stm_data_length)
276 		error = ENOMEM;
277 	if (error == 0)
278 		sc->sc_mmap_busy = 1;
279 	mtx_unlock(&sc->sc_mtx);
280 	if (error)
281 		return (error);
282 
283 	transfer.tx_cmd = transfer.rx_cmd = (void *)sc->sc_mmap_kvaddr;
284 	transfer.tx_cmd_sz = transfer.rx_cmd_sz = stm->stm_command_length;
285 	transfer.tx_data = transfer.rx_data =
286 	    (void *)(sc->sc_mmap_kvaddr + stm->stm_command_length);
287 	transfer.tx_data_sz = transfer.rx_data_sz = stm->stm_data_length;
288 	error = SPIBUS_TRANSFER(device_get_parent(dev), dev, &transfer);
289 
290 	mtx_lock(&sc->sc_mtx);
291 	KASSERT(sc->sc_mmap_busy, ("mmap no longer marked busy"));
292 	sc->sc_mmap_busy = 0;
293 	mtx_unlock(&sc->sc_mtx);
294 	return (error);
295 }
296 
297 static int
298 spigen_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
299     struct thread *td)
300 {
301 	device_t dev = cdev->si_drv1;
302 	struct spigen_softc *sc = device_get_softc(dev);
303 	int error;
304 
305 	switch (cmd) {
306 	case SPIGENIOC_TRANSFER:
307 		error = spigen_transfer(cdev, (struct spigen_transfer *)data);
308 		break;
309 	case SPIGENIOC_TRANSFER_MMAPPED:
310 		error = spigen_transfer_mmapped(cdev, (struct spigen_transfer_mmapped *)data);
311 		break;
312 	case SPIGENIOC_GET_CLOCK_SPEED:
313 		mtx_lock(&sc->sc_mtx);
314 		*(uint32_t *)data = sc->sc_clock_speed;
315 		/* XXX TODO: implement spibus ivar call */
316 		mtx_unlock(&sc->sc_mtx);
317 		error = 0;
318 		break;
319 	case SPIGENIOC_SET_CLOCK_SPEED:
320 		mtx_lock(&sc->sc_mtx);
321 		sc->sc_clock_speed = *(uint32_t *)data;
322 		mtx_unlock(&sc->sc_mtx);
323 		error = 0;
324 		break;
325 	default:
326 		error = EOPNOTSUPP;
327 	}
328 	return (error);
329 }
330 
331 static int
332 spigen_mmap_single(struct cdev *cdev, vm_ooffset_t *offset,
333     vm_size_t size, struct vm_object **object, int nprot)
334 {
335 	device_t dev = cdev->si_drv1;
336 	struct spigen_softc *sc = device_get_softc(dev);
337 	vm_page_t *m;
338 	size_t n, pages;
339 
340 	if (size == 0 ||
341 	    (nprot & (PROT_EXEC | PROT_READ | PROT_WRITE))
342 	    != (PROT_READ | PROT_WRITE))
343 		return (EINVAL);
344 	size = roundup2(size, PAGE_SIZE);
345 	pages = size / PAGE_SIZE;
346 
347 	mtx_lock(&sc->sc_mtx);
348 	if (sc->sc_mmap_buffer != NULL) {
349 		mtx_unlock(&sc->sc_mtx);
350 		return (EBUSY);
351 	} else if (size > sc->sc_command_length_max + sc->sc_data_length_max) {
352 		mtx_unlock(&sc->sc_mtx);
353 		return (E2BIG);
354 	}
355 	sc->sc_mmap_buffer_size = size;
356 	*offset = 0;
357 	sc->sc_mmap_buffer = *object = vm_pager_allocate(OBJT_PHYS, 0, size,
358 	    nprot, *offset, curthread->td_ucred);
359 	m = malloc(sizeof(*m) * pages, M_TEMP, M_WAITOK);
360 	VM_OBJECT_WLOCK(*object);
361 	vm_object_reference_locked(*object); // kernel and userland both
362 	for (n = 0; n < pages; n++) {
363 		m[n] = vm_page_grab(*object, n,
364 		    VM_ALLOC_NOBUSY | VM_ALLOC_ZERO | VM_ALLOC_WIRED);
365 		m[n]->valid = VM_PAGE_BITS_ALL;
366 	}
367 	VM_OBJECT_WUNLOCK(*object);
368 	sc->sc_mmap_kvaddr = kva_alloc(size);
369 	pmap_qenter(sc->sc_mmap_kvaddr, m, pages);
370 	free(m, M_TEMP);
371 	mtx_unlock(&sc->sc_mtx);
372 
373 	if (*object == NULL)
374 		 return (EINVAL);
375 	return (0);
376 }
377 
378 static int
379 spigen_close(struct cdev *cdev, int fflag, int devtype, struct thread *td)
380 {
381 	device_t dev = cdev->si_drv1;
382 	struct spigen_softc *sc = device_get_softc(dev);
383 
384 	mtx_lock(&sc->sc_mtx);
385 	if (sc->sc_mmap_buffer != NULL) {
386 		pmap_qremove(sc->sc_mmap_kvaddr,
387 		    sc->sc_mmap_buffer_size / PAGE_SIZE);
388 		kva_free(sc->sc_mmap_kvaddr, sc->sc_mmap_buffer_size);
389 		sc->sc_mmap_kvaddr = 0;
390 		vm_object_deallocate(sc->sc_mmap_buffer);
391 		sc->sc_mmap_buffer = NULL;
392 		sc->sc_mmap_buffer_size = 0;
393 	}
394 	mtx_unlock(&sc->sc_mtx);
395 	return (0);
396 }
397 
398 static int
399 spigen_detach(device_t dev)
400 {
401 
402 	return (EIO);
403 }
404 
405 static devclass_t spigen_devclass;
406 
407 static device_method_t spigen_methods[] = {
408 	/* Device interface */
409 #ifdef FDT
410 	DEVMETHOD(device_identify,	spigen_identify),
411 #endif
412 	DEVMETHOD(device_probe,		spigen_probe),
413 	DEVMETHOD(device_attach,	spigen_attach),
414 	DEVMETHOD(device_detach,	spigen_detach),
415 
416 	{ 0, 0 }
417 };
418 
419 static driver_t spigen_driver = {
420 	"spigen",
421 	spigen_methods,
422 	sizeof(struct spigen_softc),
423 };
424 
425 DRIVER_MODULE(spigen, spibus, spigen_driver, spigen_devclass, 0, 0);
426