xref: /freebsd/sys/dev/spibus/spigen.c (revision 7f9dff23d3092aa33ad45b2b63e52469b3c13a6e)
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 	device_set_desc(dev, "SPI Generic IO");
85 	return (0);
86 }
87 
88 static int spigen_open(struct cdev *, int, int, struct thread *);
89 static int spigen_ioctl(struct cdev *, u_long, caddr_t, int, struct thread *);
90 static int spigen_close(struct cdev *, int, int, struct thread *);
91 static d_mmap_single_t spigen_mmap_single;
92 
93 static struct cdevsw spigen_cdevsw = {
94 	.d_version =     D_VERSION,
95 	.d_name =        "spigen",
96 	.d_open =        spigen_open,
97 	.d_ioctl =       spigen_ioctl,
98 	.d_mmap_single = spigen_mmap_single,
99 	.d_close =       spigen_close
100 };
101 
102 static int
103 spigen_command_length_max_proc(SYSCTL_HANDLER_ARGS)
104 {
105 	struct spigen_softc *sc = (struct spigen_softc *)arg1;
106 	uint32_t command_length_max;
107 	int error;
108 
109 	mtx_lock(&sc->sc_mtx);
110 	command_length_max = sc->sc_command_length_max;
111 	mtx_unlock(&sc->sc_mtx);
112 	error = sysctl_handle_int(oidp, &command_length_max,
113 	    sizeof(command_length_max), req);
114 	if (error == 0 && req->newptr != NULL) {
115 		mtx_lock(&sc->sc_mtx);
116 		if (sc->sc_mmap_buffer != NULL)
117 			error = EBUSY;
118 		else
119 			sc->sc_command_length_max = command_length_max;
120 		mtx_unlock(&sc->sc_mtx);
121 	}
122 	return (error);
123 }
124 
125 static int
126 spigen_data_length_max_proc(SYSCTL_HANDLER_ARGS)
127 {
128 	struct spigen_softc *sc = (struct spigen_softc *)arg1;
129 	uint32_t data_length_max;
130 	int error;
131 
132 	mtx_lock(&sc->sc_mtx);
133 	data_length_max = sc->sc_data_length_max;
134 	mtx_unlock(&sc->sc_mtx);
135 	error = sysctl_handle_int(oidp, &data_length_max,
136 	    sizeof(data_length_max), req);
137 	if (error == 0 && req->newptr != NULL) {
138 		mtx_lock(&sc->sc_mtx);
139 		if (sc->sc_mmap_buffer != NULL)
140 			error = EBUSY;
141 		else
142 			sc->sc_data_length_max = data_length_max;
143 		mtx_unlock(&sc->sc_mtx);
144 	}
145 	return (error);
146 }
147 
148 static void
149 spigen_sysctl_init(struct spigen_softc *sc)
150 {
151 	struct sysctl_ctx_list *ctx;
152 	struct sysctl_oid *tree_node;
153 	struct sysctl_oid_list *tree;
154 
155 	/*
156 	 * Add system sysctl tree/handlers.
157 	 */
158 	ctx = device_get_sysctl_ctx(sc->sc_dev);
159 	tree_node = device_get_sysctl_tree(sc->sc_dev);
160 	tree = SYSCTL_CHILDREN(tree_node);
161 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "command_length_max",
162 	    CTLFLAG_MPSAFE | CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
163 	    spigen_command_length_max_proc, "IU", "SPI command header portion (octets)");
164 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "data_length_max",
165 	    CTLFLAG_MPSAFE | CTLFLAG_RW | CTLTYPE_UINT, sc, sizeof(*sc),
166 	    spigen_data_length_max_proc, "IU", "SPI data trailer portion (octets)");
167 	SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "data", CTLFLAG_RW,
168 	    &sc->sc_debug, 0, "debug flags");
169 
170 }
171 
172 static int
173 spigen_attach(device_t dev)
174 {
175 	struct spigen_softc *sc;
176 	const int unit = device_get_unit(dev);
177 
178 	sc = device_get_softc(dev);
179 	sc->sc_dev = dev;
180 	sc->sc_cdev = make_dev(&spigen_cdevsw, unit,
181 	    UID_ROOT, GID_OPERATOR, 0660, "spigen%d", unit);
182 	sc->sc_cdev->si_drv1 = dev;
183 	sc->sc_command_length_max = PAGE_SIZE;
184 	sc->sc_data_length_max = PAGE_SIZE;
185 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
186 	spigen_sysctl_init(sc);
187 
188 	return (0);
189 }
190 
191 static int
192 spigen_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
193 {
194 
195 	return (0);
196 }
197 
198 static int
199 spigen_transfer(struct cdev *cdev, struct spigen_transfer *st)
200 {
201 	struct spi_command transfer = SPI_COMMAND_INITIALIZER;
202 	device_t dev = cdev->si_drv1;
203 	struct spigen_softc *sc = device_get_softc(dev);
204 	int error = 0;
205 
206 	mtx_lock(&sc->sc_mtx);
207 	if (st->st_command.iov_len == 0 || st->st_data.iov_len == 0)
208 		error = EINVAL;
209 	else if (st->st_command.iov_len > sc->sc_command_length_max ||
210 	    st->st_data.iov_len > sc->sc_data_length_max)
211 		error = ENOMEM;
212 	mtx_unlock(&sc->sc_mtx);
213 	if (error)
214 		return (error);
215 
216 #if 0
217 	device_printf(dev, "cmd %p %u data %p %u\n", st->st_command.iov_base,
218 	    st->st_command.iov_len, st->st_data.iov_base, st->st_data.iov_len);
219 #endif
220 	transfer.tx_cmd = transfer.rx_cmd = malloc(st->st_command.iov_len,
221 	    M_DEVBUF, M_WAITOK);
222 	if (transfer.tx_cmd == NULL)
223 		return (ENOMEM);
224 	transfer.tx_data = transfer.rx_data = malloc(st->st_data.iov_len,
225 	    M_DEVBUF, M_WAITOK);
226 	if (transfer.tx_data == NULL) {
227 		free(transfer.tx_cmd, M_DEVBUF);
228 		return (ENOMEM);
229 	}
230 
231 	error = copyin(st->st_command.iov_base, transfer.tx_cmd,
232 	    transfer.tx_cmd_sz = transfer.rx_cmd_sz = st->st_command.iov_len);
233 	if (error == 0)
234 		error = copyin(st->st_data.iov_base, transfer.tx_data,
235 		    transfer.tx_data_sz = transfer.rx_data_sz =
236 		                          st->st_data.iov_len);
237 	if (error == 0)
238 		error = SPIBUS_TRANSFER(device_get_parent(dev), dev, &transfer);
239 	if (error == 0) {
240 		error = copyout(transfer.rx_cmd, st->st_command.iov_base,
241 		    transfer.rx_cmd_sz);
242 		if (error == 0)
243 			error = copyout(transfer.rx_data, st->st_data.iov_base,
244 			    transfer.rx_data_sz);
245 	}
246 
247 	free(transfer.tx_cmd, M_DEVBUF);
248 	free(transfer.tx_data, M_DEVBUF);
249 	return (error);
250 }
251 
252 static int
253 spigen_transfer_mmapped(struct cdev *cdev, struct spigen_transfer_mmapped *stm)
254 {
255 	struct spi_command transfer = SPI_COMMAND_INITIALIZER;
256 	device_t dev = cdev->si_drv1;
257 	struct spigen_softc *sc = device_get_softc(dev);
258 	int error = 0;
259 
260 	mtx_lock(&sc->sc_mtx);
261 	if (sc->sc_mmap_busy)
262 		error = EBUSY;
263 	else if (stm->stm_command_length > sc->sc_command_length_max ||
264 	    stm->stm_data_length > sc->sc_data_length_max)
265 		error = E2BIG;
266 	else if (sc->sc_mmap_buffer == NULL)
267 		error = EINVAL;
268 	else if (sc->sc_mmap_buffer_size <
269 	    stm->stm_command_length + stm->stm_data_length)
270 		error = ENOMEM;
271 	if (error == 0)
272 		sc->sc_mmap_busy = 1;
273 	mtx_unlock(&sc->sc_mtx);
274 	if (error)
275 		return (error);
276 
277 	transfer.tx_cmd = transfer.rx_cmd = (void *)sc->sc_mmap_kvaddr;
278 	transfer.tx_cmd_sz = transfer.rx_cmd_sz = stm->stm_command_length;
279 	transfer.tx_data = transfer.rx_data =
280 	    (void *)(sc->sc_mmap_kvaddr + stm->stm_command_length);
281 	transfer.tx_data_sz = transfer.rx_data_sz = stm->stm_data_length;
282 	error = SPIBUS_TRANSFER(device_get_parent(dev), dev, &transfer);
283 
284 	mtx_lock(&sc->sc_mtx);
285 	KASSERT(sc->sc_mmap_busy, ("mmap no longer marked busy"));
286 	sc->sc_mmap_busy = 0;
287 	mtx_unlock(&sc->sc_mtx);
288 	return (error);
289 }
290 
291 static int
292 spigen_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
293     struct thread *td)
294 {
295 	device_t dev = cdev->si_drv1;
296 	struct spigen_softc *sc = device_get_softc(dev);
297 	int error;
298 
299 	switch (cmd) {
300 	case SPIGENIOC_TRANSFER:
301 		error = spigen_transfer(cdev, (struct spigen_transfer *)data);
302 		break;
303 	case SPIGENIOC_TRANSFER_MMAPPED:
304 		error = spigen_transfer_mmapped(cdev, (struct spigen_transfer_mmapped *)data);
305 		break;
306 	case SPIGENIOC_GET_CLOCK_SPEED:
307 		mtx_lock(&sc->sc_mtx);
308 		*(uint32_t *)data = sc->sc_clock_speed;
309 		/* XXX TODO: implement spibus ivar call */
310 		mtx_unlock(&sc->sc_mtx);
311 		error = 0;
312 		break;
313 	case SPIGENIOC_SET_CLOCK_SPEED:
314 		mtx_lock(&sc->sc_mtx);
315 		sc->sc_clock_speed = *(uint32_t *)data;
316 		mtx_unlock(&sc->sc_mtx);
317 		error = 0;
318 		break;
319 	default:
320 		error = EOPNOTSUPP;
321 	}
322 	return (error);
323 }
324 
325 static int
326 spigen_mmap_single(struct cdev *cdev, vm_ooffset_t *offset,
327     vm_size_t size, struct vm_object **object, int nprot)
328 {
329 	device_t dev = cdev->si_drv1;
330 	struct spigen_softc *sc = device_get_softc(dev);
331 	vm_page_t *m;
332 	size_t n, pages;
333 
334 	if (size == 0 ||
335 	    (nprot & (PROT_EXEC | PROT_READ | PROT_WRITE))
336 	    != (PROT_READ | PROT_WRITE))
337 		return (EINVAL);
338 	size = roundup2(size, PAGE_SIZE);
339 	pages = size / PAGE_SIZE;
340 
341 	mtx_lock(&sc->sc_mtx);
342 	if (sc->sc_mmap_buffer != NULL) {
343 		mtx_unlock(&sc->sc_mtx);
344 		return (EBUSY);
345 	} else if (size > sc->sc_command_length_max + sc->sc_data_length_max) {
346 		mtx_unlock(&sc->sc_mtx);
347 		return (E2BIG);
348 	}
349 	sc->sc_mmap_buffer_size = size;
350 	*offset = 0;
351 	sc->sc_mmap_buffer = *object = vm_pager_allocate(OBJT_PHYS, 0, size,
352 	    nprot, *offset, curthread->td_ucred);
353 	m = malloc(sizeof(*m) * pages, M_TEMP, M_WAITOK);
354 	VM_OBJECT_WLOCK(*object);
355 	vm_object_reference_locked(*object); // kernel and userland both
356 	for (n = 0; n < pages; n++) {
357 		m[n] = vm_page_grab(*object, n,
358 		    VM_ALLOC_NOBUSY | VM_ALLOC_ZERO | VM_ALLOC_WIRED);
359 		m[n]->valid = VM_PAGE_BITS_ALL;
360 	}
361 	VM_OBJECT_WUNLOCK(*object);
362 	sc->sc_mmap_kvaddr = kva_alloc(size);
363 	pmap_qenter(sc->sc_mmap_kvaddr, m, pages);
364 	free(m, M_TEMP);
365 	mtx_unlock(&sc->sc_mtx);
366 
367 	if (*object == NULL)
368 		 return (EINVAL);
369 	return (0);
370 }
371 
372 static int
373 spigen_close(struct cdev *cdev, int fflag, int devtype, struct thread *td)
374 {
375 	device_t dev = cdev->si_drv1;
376 	struct spigen_softc *sc = device_get_softc(dev);
377 
378 	mtx_lock(&sc->sc_mtx);
379 	if (sc->sc_mmap_buffer != NULL) {
380 		pmap_qremove(sc->sc_mmap_kvaddr,
381 		    sc->sc_mmap_buffer_size / PAGE_SIZE);
382 		kva_free(sc->sc_mmap_kvaddr, sc->sc_mmap_buffer_size);
383 		sc->sc_mmap_kvaddr = 0;
384 		vm_object_deallocate(sc->sc_mmap_buffer);
385 		sc->sc_mmap_buffer = NULL;
386 		sc->sc_mmap_buffer_size = 0;
387 	}
388 	mtx_unlock(&sc->sc_mtx);
389 	return (0);
390 }
391 
392 static int
393 spigen_detach(device_t dev)
394 {
395 
396 	return (EIO);
397 }
398 
399 static devclass_t spigen_devclass;
400 
401 static device_method_t spigen_methods[] = {
402 	/* Device interface */
403 #ifdef FDT
404 	DEVMETHOD(device_identify,	spigen_identify),
405 #endif
406 	DEVMETHOD(device_probe,		spigen_probe),
407 	DEVMETHOD(device_attach,	spigen_attach),
408 	DEVMETHOD(device_detach,	spigen_detach),
409 
410 	{ 0, 0 }
411 };
412 
413 static driver_t spigen_driver = {
414 	"spigen",
415 	spigen_methods,
416 	sizeof(struct spigen_softc),
417 };
418 
419 DRIVER_MODULE(spigen, spibus, spigen_driver, spigen_devclass, 0, 0);
420