1 /*-
2 * Copyright (c) 2006 M. Warner Losh.
3 * Copyright (c) 2011-2012 Ian Lepore.
4 * All rights reserved.
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, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/conf.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/mbuf.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/rman.h>
41 #include <sys/sx.h>
42
43 #include <machine/bus.h>
44
45 #include <arm/at91/at91_spireg.h>
46 #include <arm/at91/at91_pdcreg.h>
47
48 #include <dev/spibus/spi.h>
49
50 #include "spibus_if.h"
51
52 struct at91_spi_softc
53 {
54 device_t dev; /* Myself */
55 void *intrhand; /* Interrupt handle */
56 struct resource *irq_res; /* IRQ resource */
57 struct resource *mem_res; /* Memory resource */
58 bus_dma_tag_t dmatag; /* bus dma tag for transfers */
59 bus_dmamap_t map[4]; /* Maps for the transaction */
60 struct sx xfer_mtx; /* Enforce one transfer at a time */
61 uint32_t xfer_done; /* interrupt<->mainthread signaling */
62 };
63
64 #define CS_TO_MR(cs) ((~(1 << (cs)) & 0x0f) << 16)
65
66 static inline uint32_t
67 RD4(struct at91_spi_softc *sc, bus_size_t off)
68 {
69
70 return (bus_read_4(sc->mem_res, off));
71 }
72
73 static inline void
74 WR4(struct at91_spi_softc *sc, bus_size_t off, uint32_t val)
75 {
76
77 bus_write_4(sc->mem_res, off, val);
78 }
79
80 /* bus entry points */
81 static int at91_spi_attach(device_t dev);
82 static int at91_spi_detach(device_t dev);
83 static int at91_spi_probe(device_t dev);
84 static int at91_spi_transfer(device_t dev, device_t child,
85 struct spi_command *cmd);
86
87 /* helper routines */
88 static void at91_getaddr(void *arg, bus_dma_segment_t *segs, int nsegs,
89 int error);
90 static int at91_spi_activate(device_t dev);
91 static void at91_spi_deactivate(device_t dev);
92 static void at91_spi_intr(void *arg);
93
94 static int
95 at91_spi_probe(device_t dev)
96 {
97
98 device_set_desc(dev, "AT91 SPI");
99 return (0);
100 }
101
102 static int
103 at91_spi_attach(device_t dev)
104 {
105 struct at91_spi_softc *sc;
106 int err;
107 uint32_t csr;
108
109 sc = device_get_softc(dev);
110
111 sc->dev = dev;
112 sx_init(&sc->xfer_mtx, device_get_nameunit(dev));
113
114 /*
115 * Allocate resources.
116 */
117 err = at91_spi_activate(dev);
118 if (err)
119 goto out;
120
121 /*
122 * Set up the hardware.
123 */
124
125 WR4(sc, SPI_CR, SPI_CR_SWRST);
126 /* "Software Reset must be Written Twice" erratum */
127 WR4(sc, SPI_CR, SPI_CR_SWRST);
128 WR4(sc, SPI_IDR, 0xffffffff);
129
130 WR4(sc, SPI_MR, (0xf << 24) | SPI_MR_MSTR | SPI_MR_MODFDIS |
131 CS_TO_MR(0));
132
133 /*
134 * For now, run the bus at the slowest speed possible as otherwise we
135 * may encounter data corruption on transmit as seen with ETHERNUT5
136 * and AT45DB321D even though both board and slave device can take
137 * more.
138 * This also serves as a work-around for the "NPCSx rises if no data
139 * data is to be transmitted" erratum. The ideal workaround for the
140 * latter is to take the chip select control away from the peripheral
141 * and manage it directly as a GPIO line. The easy solution is to
142 * slow down the bus so dramatically that it just never gets starved
143 * as may be seen when the OCHI controller is running and consuming
144 * memory and APB bandwidth.
145 * Also, currently we lack a way for lettting both the board and the
146 * slave devices take their maximum supported SPI clocks into account.
147 */
148 csr = SPI_CSR_CPOL | (4 << 16) | (0xff << 8);
149 WR4(sc, SPI_CSR0, csr);
150 WR4(sc, SPI_CSR1, csr);
151 WR4(sc, SPI_CSR2, csr);
152 WR4(sc, SPI_CSR3, csr);
153
154 WR4(sc, SPI_CR, SPI_CR_SPIEN);
155
156 WR4(sc, PDC_PTCR, PDC_PTCR_TXTDIS);
157 WR4(sc, PDC_PTCR, PDC_PTCR_RXTDIS);
158 WR4(sc, PDC_RNPR, 0);
159 WR4(sc, PDC_RNCR, 0);
160 WR4(sc, PDC_TNPR, 0);
161 WR4(sc, PDC_TNCR, 0);
162 WR4(sc, PDC_RPR, 0);
163 WR4(sc, PDC_RCR, 0);
164 WR4(sc, PDC_TPR, 0);
165 WR4(sc, PDC_TCR, 0);
166 RD4(sc, SPI_RDR);
167 RD4(sc, SPI_SR);
168
169 device_add_child(dev, "spibus", -1);
170 bus_generic_attach(dev);
171 out:
172 if (err)
173 at91_spi_deactivate(dev);
174 return (err);
175 }
176
177 static int
178 at91_spi_detach(device_t dev)
179 {
180
181 return (EBUSY); /* XXX */
182 }
183
184 static int
185 at91_spi_activate(device_t dev)
186 {
187 struct at91_spi_softc *sc;
188 int err, i, rid;
189
190 sc = device_get_softc(dev);
191 err = ENOMEM;
192
193 rid = 0;
194 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
195 RF_ACTIVE);
196 if (sc->mem_res == NULL)
197 goto out;
198
199 rid = 0;
200 sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
201 RF_ACTIVE);
202 if (sc->irq_res == NULL)
203 goto out;
204 err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
205 NULL, at91_spi_intr, sc, &sc->intrhand);
206 if (err != 0)
207 goto out;
208
209 err = bus_dma_tag_create(bus_get_dma_tag(dev), 1, 0,
210 BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL, 2048, 1,
211 2048, BUS_DMA_ALLOCNOW, NULL, NULL, &sc->dmatag);
212 if (err != 0)
213 goto out;
214
215 for (i = 0; i < 4; i++) {
216 err = bus_dmamap_create(sc->dmatag, 0, &sc->map[i]);
217 if (err != 0)
218 goto out;
219 }
220 out:
221 if (err != 0)
222 at91_spi_deactivate(dev);
223 return (err);
224 }
225
226 static void
227 at91_spi_deactivate(device_t dev)
228 {
229 struct at91_spi_softc *sc;
230 int i;
231
232 sc = device_get_softc(dev);
233 bus_generic_detach(dev);
234
235 for (i = 0; i < 4; i++)
236 if (sc->map[i])
237 bus_dmamap_destroy(sc->dmatag, sc->map[i]);
238
239 if (sc->dmatag)
240 bus_dma_tag_destroy(sc->dmatag);
241
242 if (sc->intrhand)
243 bus_teardown_intr(dev, sc->irq_res, sc->intrhand);
244 sc->intrhand = NULL;
245 if (sc->irq_res)
246 bus_release_resource(dev, SYS_RES_IRQ,
247 rman_get_rid(sc->irq_res), sc->irq_res);
248 sc->irq_res = NULL;
249
250 if (sc->mem_res)
251 bus_release_resource(dev, SYS_RES_MEMORY,
252 rman_get_rid(sc->mem_res), sc->mem_res);
253 sc->mem_res = NULL;
254 }
255
256 static void
257 at91_getaddr(void *arg, bus_dma_segment_t *segs, int nsegs __unused,
258 int error)
259 {
260
261 if (error != 0)
262 return;
263 *(bus_addr_t *)arg = segs[0].ds_addr;
264 }
265
266 static int
267 at91_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
268 {
269 struct at91_spi_softc *sc;
270 bus_addr_t addr;
271 int err, i, j, mode[4];
272
273 KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
274 ("%s: TX/RX command sizes should be equal", __func__));
275 KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
276 ("%s: TX/RX data sizes should be equal", __func__));
277
278 sc = device_get_softc(dev);
279 i = 0;
280
281 sx_xlock(&sc->xfer_mtx);
282
283 /*
284 * Disable transfers while we set things up.
285 */
286 WR4(sc, PDC_PTCR, PDC_PTCR_TXTDIS | PDC_PTCR_RXTDIS);
287
288 #ifdef SPI_CHIPSEL_SUPPORT
289 if (cmd->cs < 0 || cmd->cs > 3) {
290 device_printf(dev,
291 "Invalid chip select %d requested by %s\n", cmd->cs,
292 device_get_nameunit(child));
293 err = EINVAL;
294 goto out;
295 }
296 #ifdef SPI_CHIP_SELECT_HIGH_SUPPORT
297 if (at91_is_rm92() && cmd->cs == 0 &&
298 (cmd->flags & SPI_CHIP_SELECT_HIGH) != 0) {
299 device_printf(dev,
300 "Invalid chip select high requested by %s\n",
301 device_get_nameunit(child));
302 err = EINVAL;
303 goto out;
304 }
305 #endif
306 WR4(sc, SPI_MR, (RD4(sc, SPI_MR) & ~0x000f0000) | CS_TO_MR(cmd->cs));
307 #endif
308
309 /*
310 * Set up the TX side of the transfer.
311 */
312 if ((err = bus_dmamap_load(sc->dmatag, sc->map[i], cmd->tx_cmd,
313 cmd->tx_cmd_sz, at91_getaddr, &addr, 0)) != 0)
314 goto out;
315 WR4(sc, PDC_TPR, addr);
316 WR4(sc, PDC_TCR, cmd->tx_cmd_sz);
317 bus_dmamap_sync(sc->dmatag, sc->map[i], BUS_DMASYNC_PREWRITE);
318 mode[i++] = BUS_DMASYNC_POSTWRITE;
319 if (cmd->tx_data_sz > 0) {
320 if ((err = bus_dmamap_load(sc->dmatag, sc->map[i],
321 cmd->tx_data, cmd->tx_data_sz, at91_getaddr, &addr, 0)) !=
322 0)
323 goto out;
324 WR4(sc, PDC_TNPR, addr);
325 WR4(sc, PDC_TNCR, cmd->tx_data_sz);
326 bus_dmamap_sync(sc->dmatag, sc->map[i], BUS_DMASYNC_PREWRITE);
327 mode[i++] = BUS_DMASYNC_POSTWRITE;
328 }
329
330 /*
331 * Set up the RX side of the transfer.
332 */
333 if ((err = bus_dmamap_load(sc->dmatag, sc->map[i], cmd->rx_cmd,
334 cmd->rx_cmd_sz, at91_getaddr, &addr, 0)) != 0)
335 goto out;
336 WR4(sc, PDC_RPR, addr);
337 WR4(sc, PDC_RCR, cmd->rx_cmd_sz);
338 bus_dmamap_sync(sc->dmatag, sc->map[i], BUS_DMASYNC_PREREAD);
339 mode[i++] = BUS_DMASYNC_POSTREAD;
340 if (cmd->rx_data_sz > 0) {
341 if ((err = bus_dmamap_load(sc->dmatag, sc->map[i],
342 cmd->rx_data, cmd->rx_data_sz, at91_getaddr, &addr, 0)) !=
343 0)
344 goto out;
345 WR4(sc, PDC_RNPR, addr);
346 WR4(sc, PDC_RNCR, cmd->rx_data_sz);
347 bus_dmamap_sync(sc->dmatag, sc->map[i], BUS_DMASYNC_PREREAD);
348 mode[i++] = BUS_DMASYNC_POSTREAD;
349 }
350
351 /*
352 * Start the transfer, wait for it to complete.
353 */
354 sc->xfer_done = 0;
355 WR4(sc, SPI_IER, SPI_SR_RXBUFF);
356 WR4(sc, PDC_PTCR, PDC_PTCR_TXTEN | PDC_PTCR_RXTEN);
357 do
358 err = tsleep(&sc->xfer_done, PCATCH | PZERO, "at91_spi", hz);
359 while (sc->xfer_done == 0 && err != EINTR);
360
361 /*
362 * Stop the transfer and clean things up.
363 */
364 WR4(sc, PDC_PTCR, PDC_PTCR_TXTDIS | PDC_PTCR_RXTDIS);
365 if (err == 0)
366 for (j = 0; j < i; j++)
367 bus_dmamap_sync(sc->dmatag, sc->map[j], mode[j]);
368 out:
369 for (j = 0; j < i; j++)
370 bus_dmamap_unload(sc->dmatag, sc->map[j]);
371
372 sx_xunlock(&sc->xfer_mtx);
373
374 return (err);
375 }
376
377 static void
378 at91_spi_intr(void *arg)
379 {
380 struct at91_spi_softc *sc;
381 uint32_t sr;
382
383 sc = (struct at91_spi_softc*)arg;
384
385 sr = RD4(sc, SPI_SR) & RD4(sc, SPI_IMR);
386 if ((sr & SPI_SR_RXBUFF) != 0) {
387 sc->xfer_done = 1;
388 WR4(sc, SPI_IDR, SPI_SR_RXBUFF);
389 wakeup(&sc->xfer_done);
390 }
391 if ((sr & ~SPI_SR_RXBUFF) != 0) {
392 device_printf(sc->dev, "Unexpected ISR %#x\n", sr);
393 WR4(sc, SPI_IDR, sr & ~SPI_SR_RXBUFF);
394 }
395 }
396
397 static devclass_t at91_spi_devclass;
398
399 static device_method_t at91_spi_methods[] = {
400 /* Device interface */
401 DEVMETHOD(device_probe, at91_spi_probe),
402 DEVMETHOD(device_attach, at91_spi_attach),
403 DEVMETHOD(device_detach, at91_spi_detach),
404
405 /* spibus interface */
406 DEVMETHOD(spibus_transfer, at91_spi_transfer),
407
408 DEVMETHOD_END
409 };
410
411 static driver_t at91_spi_driver = {
412 "spi",
413 at91_spi_methods,
414 sizeof(struct at91_spi_softc),
415 };
416
417 DRIVER_MODULE(at91_spi, atmelarm, at91_spi_driver, at91_spi_devclass, NULL,
418 NULL);
Cache object: cfd3e8e79139f247835d23f1e1eb37cd
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