FreeBSD/Linux Kernel Cross Reference
sys/arm/mv/a37x0_spi.c
1 /*-
2 * Copyright (c) 2018, 2019 Rubicon Communications, LLC (Netgate)
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
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/mutex.h>
35 #include <sys/rman.h>
36
37 #include <machine/bus.h>
38 #include <machine/resource.h>
39 #include <machine/intr.h>
40
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 #include <dev/spibus/spi.h>
44 #include <dev/spibus/spibusvar.h>
45
46 #include "spibus_if.h"
47
48 struct a37x0_spi_softc {
49 device_t sc_dev;
50 struct mtx sc_mtx;
51 struct resource *sc_mem_res;
52 struct resource *sc_irq_res;
53 struct spi_command *sc_cmd;
54 bus_space_tag_t sc_bst;
55 bus_space_handle_t sc_bsh;
56 uint32_t sc_len;
57 uint32_t sc_maxfreq;
58 uint32_t sc_read;
59 uint32_t sc_flags;
60 uint32_t sc_written;
61 void *sc_intrhand;
62 };
63
64 #define A37X0_SPI_WRITE(_sc, _off, _val) \
65 bus_space_write_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off), (_val))
66 #define A37X0_SPI_READ(_sc, _off) \
67 bus_space_read_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off))
68 #define A37X0_SPI_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
69 #define A37X0_SPI_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
70
71 #define A37X0_SPI_BUSY (1 << 0)
72 /*
73 * While the A3700 utils from Marvell usually sets the QSF clock to 200MHz,
74 * there is no guarantee that it is correct without the proper clock framework
75 * to retrieve the actual TBG and PLL settings.
76 */
77 #define A37X0_SPI_CLOCK 200000000 /* QSF Clock 200MHz */
78
79 #define A37X0_SPI_CONTROL 0x0
80 #define A37X0_SPI_CS_SHIFT 16
81 #define A37X0_SPI_CS_MASK (0xf << A37X0_SPI_CS_SHIFT)
82 #define A37X0_SPI_CONF 0x4
83 #define A37X0_SPI_WFIFO_THRS_SHIFT 28
84 #define A37X0_SPI_RFIFO_THRS_SHIFT 24
85 #define A37X0_SPI_AUTO_CS_EN (1 << 20)
86 #define A37X0_SPI_DMA_WR_EN (1 << 19)
87 #define A37X0_SPI_DMA_RD_EN (1 << 18)
88 #define A37X0_SPI_FIFO_MODE (1 << 17)
89 #define A37X0_SPI_SRST (1 << 16)
90 #define A37X0_SPI_XFER_START (1 << 15)
91 #define A37X0_SPI_XFER_STOP (1 << 14)
92 #define A37X0_SPI_INSTR_PIN (1 << 13)
93 #define A37X0_SPI_ADDR_PIN (1 << 12)
94 #define A37X0_SPI_DATA_PIN_MASK 0x3
95 #define A37X0_SPI_DATA_PIN_SHIFT 10
96 #define A37X0_SPI_FIFO_FLUSH (1 << 9)
97 #define A37X0_SPI_RW_EN (1 << 8)
98 #define A37X0_SPI_CLK_POL (1 << 7)
99 #define A37X0_SPI_CLK_PHASE (1 << 6)
100 #define A37X0_SPI_BYTE_LEN (1 << 5)
101 #define A37X0_SPI_PSC_MASK 0x1f
102 #define A37X0_SPI_DATA_OUT 0x8
103 #define A37X0_SPI_DATA_IN 0xc
104 #define A37X0_SPI_INTR_STAT 0x28
105 #define A37X0_SPI_INTR_MASK 0x2c
106 #define A37X0_SPI_RDY (1 << 1)
107 #define A37X0_SPI_XFER_DONE (1 << 0)
108
109 static struct ofw_compat_data compat_data[] = {
110 { "marvell,armada-3700-spi", 1 },
111 { NULL, 0 }
112 };
113
114 static void a37x0_spi_intr(void *);
115
116 static int
117 a37x0_spi_wait(struct a37x0_spi_softc *sc, int timeout, uint32_t reg,
118 uint32_t mask)
119 {
120 int i;
121
122 for (i = 0; i < timeout; i++) {
123 if ((A37X0_SPI_READ(sc, reg) & mask) == 0)
124 return (0);
125 DELAY(100);
126 }
127
128 return (ETIMEDOUT);
129 }
130
131 static int
132 a37x0_spi_probe(device_t dev)
133 {
134
135 if (!ofw_bus_status_okay(dev))
136 return (ENXIO);
137 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
138 return (ENXIO);
139 device_set_desc(dev, "Armada 37x0 SPI controller");
140
141 return (BUS_PROBE_DEFAULT);
142 }
143
144 static int
145 a37x0_spi_attach(device_t dev)
146 {
147 int err, rid;
148 pcell_t maxfreq;
149 struct a37x0_spi_softc *sc;
150 uint32_t reg;
151
152 sc = device_get_softc(dev);
153 sc->sc_dev = dev;
154
155 rid = 0;
156 sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
157 RF_ACTIVE);
158 if (!sc->sc_mem_res) {
159 device_printf(dev, "cannot allocate memory window\n");
160 return (ENXIO);
161 }
162
163 sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
164 sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
165
166 rid = 0;
167 sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
168 RF_ACTIVE);
169 if (!sc->sc_irq_res) {
170 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
171 device_printf(dev, "cannot allocate interrupt\n");
172 return (ENXIO);
173 }
174
175 /* Make sure that no CS is asserted. */
176 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONTROL);
177 A37X0_SPI_WRITE(sc, A37X0_SPI_CONTROL, reg & ~A37X0_SPI_CS_MASK);
178
179 /* Reset FIFO. */
180 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONF);
181 A37X0_SPI_WRITE(sc, A37X0_SPI_CONF, reg | A37X0_SPI_FIFO_FLUSH);
182 err = a37x0_spi_wait(sc, 20, A37X0_SPI_CONF, A37X0_SPI_FIFO_FLUSH);
183 if (err != 0) {
184 bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
185 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
186 device_printf(dev, "cannot flush the controller fifo.\n");
187 return (ENXIO);
188 }
189
190 /* Reset the Controller. */
191 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONF);
192 A37X0_SPI_WRITE(sc, A37X0_SPI_CONF, reg | A37X0_SPI_SRST);
193 DELAY(1000);
194 /* Enable the single byte IO, disable FIFO. */
195 reg &= ~(A37X0_SPI_FIFO_MODE | A37X0_SPI_BYTE_LEN);
196 A37X0_SPI_WRITE(sc, A37X0_SPI_CONF, reg);
197
198 /* Disable and clear interrupts. */
199 A37X0_SPI_WRITE(sc, A37X0_SPI_INTR_MASK, 0);
200 reg = A37X0_SPI_READ(sc, A37X0_SPI_INTR_STAT);
201 A37X0_SPI_WRITE(sc, A37X0_SPI_INTR_STAT, reg);
202
203 /* Hook up our interrupt handler. */
204 if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
205 NULL, a37x0_spi_intr, sc, &sc->sc_intrhand)) {
206 bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
207 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
208 device_printf(dev, "cannot setup the interrupt handler\n");
209 return (ENXIO);
210 }
211
212 mtx_init(&sc->sc_mtx, "a37x0_spi", NULL, MTX_DEF);
213
214 /* Read the controller max-frequency. */
215 if (OF_getencprop(ofw_bus_get_node(dev), "spi-max-frequency", &maxfreq,
216 sizeof(maxfreq)) == -1)
217 maxfreq = 0;
218 sc->sc_maxfreq = maxfreq;
219
220 device_add_child(dev, "spibus", -1);
221
222 /* Probe and attach the spibus when interrupts are available. */
223 return (bus_delayed_attach_children(dev));
224 }
225
226 static int
227 a37x0_spi_detach(device_t dev)
228 {
229 int err;
230 struct a37x0_spi_softc *sc;
231
232 if ((err = device_delete_children(dev)) != 0)
233 return (err);
234 sc = device_get_softc(dev);
235 mtx_destroy(&sc->sc_mtx);
236 if (sc->sc_intrhand)
237 bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
238 if (sc->sc_irq_res)
239 bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
240 if (sc->sc_mem_res)
241 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
242
243 return (0);
244 }
245
246 static __inline void
247 a37x0_spi_rx_byte(struct a37x0_spi_softc *sc)
248 {
249 struct spi_command *cmd;
250 uint32_t read;
251 uint8_t *p;
252
253 if (sc->sc_read == sc->sc_len)
254 return;
255 cmd = sc->sc_cmd;
256 p = (uint8_t *)cmd->rx_cmd;
257 read = sc->sc_read++;
258 if (read >= cmd->rx_cmd_sz) {
259 p = (uint8_t *)cmd->rx_data;
260 read -= cmd->rx_cmd_sz;
261 }
262 p[read] = A37X0_SPI_READ(sc, A37X0_SPI_DATA_IN) & 0xff;
263 }
264
265 static __inline void
266 a37x0_spi_tx_byte(struct a37x0_spi_softc *sc)
267 {
268 struct spi_command *cmd;
269 uint32_t written;
270 uint8_t *p;
271
272 if (sc->sc_written == sc->sc_len)
273 return;
274 cmd = sc->sc_cmd;
275 p = (uint8_t *)cmd->tx_cmd;
276 written = sc->sc_written++;
277 if (written >= cmd->tx_cmd_sz) {
278 p = (uint8_t *)cmd->tx_data;
279 written -= cmd->tx_cmd_sz;
280 }
281 A37X0_SPI_WRITE(sc, A37X0_SPI_DATA_OUT, p[written]);
282 }
283
284 static __inline void
285 a37x0_spi_set_clock(struct a37x0_spi_softc *sc, uint32_t clock)
286 {
287 uint32_t psc, reg;
288
289 if (sc->sc_maxfreq > 0 && clock > sc->sc_maxfreq)
290 clock = sc->sc_maxfreq;
291 psc = A37X0_SPI_CLOCK / clock;
292 if ((A37X0_SPI_CLOCK % clock) > 0)
293 psc++;
294 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONF);
295 reg &= ~A37X0_SPI_PSC_MASK;
296 reg |= psc & A37X0_SPI_PSC_MASK;
297 A37X0_SPI_WRITE(sc, A37X0_SPI_CONF, reg);
298 }
299
300 static __inline void
301 a37x0_spi_set_pins(struct a37x0_spi_softc *sc, uint32_t npins)
302 {
303 uint32_t reg;
304
305 /* Sets single, dual or quad SPI mode. */
306 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONF);
307 reg &= ~(A37X0_SPI_DATA_PIN_MASK << A37X0_SPI_DATA_PIN_SHIFT);
308 reg |= (npins / 2) << A37X0_SPI_DATA_PIN_SHIFT;
309 reg |= A37X0_SPI_INSTR_PIN | A37X0_SPI_ADDR_PIN;
310 A37X0_SPI_WRITE(sc, A37X0_SPI_CONF, reg);
311 }
312
313 static __inline void
314 a37x0_spi_set_mode(struct a37x0_spi_softc *sc, uint32_t mode)
315 {
316 uint32_t reg;
317
318 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONF);
319 switch (mode) {
320 case 0:
321 reg &= ~(A37X0_SPI_CLK_PHASE | A37X0_SPI_CLK_POL);
322 break;
323 case 1:
324 reg &= ~A37X0_SPI_CLK_POL;
325 reg |= A37X0_SPI_CLK_PHASE;
326 break;
327 case 2:
328 reg &= ~A37X0_SPI_CLK_PHASE;
329 reg |= A37X0_SPI_CLK_POL;
330 break;
331 case 3:
332 reg |= (A37X0_SPI_CLK_PHASE | A37X0_SPI_CLK_POL);
333 break;
334 }
335 A37X0_SPI_WRITE(sc, A37X0_SPI_CONF, reg);
336 }
337
338 static void
339 a37x0_spi_intr(void *arg)
340 {
341 struct a37x0_spi_softc *sc;
342 uint32_t status;
343
344 sc = (struct a37x0_spi_softc *)arg;
345 A37X0_SPI_LOCK(sc);
346
347 /* Filter stray interrupts. */
348 if ((sc->sc_flags & A37X0_SPI_BUSY) == 0) {
349 A37X0_SPI_UNLOCK(sc);
350 return;
351 }
352
353 status = A37X0_SPI_READ(sc, A37X0_SPI_INTR_STAT);
354 if (status & A37X0_SPI_XFER_DONE)
355 a37x0_spi_rx_byte(sc);
356
357 /* Clear the interrupt status. */
358 A37X0_SPI_WRITE(sc, A37X0_SPI_INTR_STAT, status);
359
360 /* Check for end of transfer. */
361 if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len)
362 wakeup(sc->sc_dev);
363 else
364 a37x0_spi_tx_byte(sc);
365
366 A37X0_SPI_UNLOCK(sc);
367 }
368
369 static int
370 a37x0_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
371 {
372 int timeout;
373 struct a37x0_spi_softc *sc;
374 uint32_t clock, cs, mode, reg;
375
376 KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
377 ("TX/RX command sizes should be equal"));
378 KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
379 ("TX/RX data sizes should be equal"));
380
381 /* Get the proper data for this child. */
382 spibus_get_cs(child, &cs);
383 cs &= ~SPIBUS_CS_HIGH;
384 if (cs > 3) {
385 device_printf(dev,
386 "Invalid CS %d requested by %s\n", cs,
387 device_get_nameunit(child));
388 return (EINVAL);
389 }
390 spibus_get_clock(child, &clock);
391 if (clock == 0) {
392 device_printf(dev,
393 "Invalid clock %uHz requested by %s\n", clock,
394 device_get_nameunit(child));
395 return (EINVAL);
396 }
397 spibus_get_mode(child, &mode);
398 if (mode > 3) {
399 device_printf(dev,
400 "Invalid mode %u requested by %s\n", mode,
401 device_get_nameunit(child));
402 return (EINVAL);
403 }
404
405 sc = device_get_softc(dev);
406 A37X0_SPI_LOCK(sc);
407
408 /* Wait until the controller is free. */
409 while (sc->sc_flags & A37X0_SPI_BUSY)
410 mtx_sleep(dev, &sc->sc_mtx, 0, "a37x0_spi", 0);
411
412 /* Now we have control over SPI controller. */
413 sc->sc_flags = A37X0_SPI_BUSY;
414
415 /* Set transfer mode and clock. */
416 a37x0_spi_set_mode(sc, mode);
417 a37x0_spi_set_pins(sc, 1);
418 a37x0_spi_set_clock(sc, clock);
419
420 /* Set CS. */
421 A37X0_SPI_WRITE(sc, A37X0_SPI_CONTROL, 1 << (A37X0_SPI_CS_SHIFT + cs));
422
423 /* Save a pointer to the SPI command. */
424 sc->sc_cmd = cmd;
425 sc->sc_read = 0;
426 sc->sc_written = 0;
427 sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
428
429 /* Clear interrupts. */
430 reg = A37X0_SPI_READ(sc, A37X0_SPI_INTR_STAT);
431 A37X0_SPI_WRITE(sc, A37X0_SPI_INTR_STAT, reg);
432
433 while ((sc->sc_len - sc->sc_written) > 0) {
434 /*
435 * Write to start the transmission and read the byte
436 * back when ready.
437 */
438 a37x0_spi_tx_byte(sc);
439 timeout = 1000;
440 while (--timeout > 0) {
441 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONTROL);
442 if (reg & A37X0_SPI_XFER_DONE)
443 break;
444 DELAY(1);
445 }
446 if (timeout == 0)
447 break;
448 a37x0_spi_rx_byte(sc);
449 }
450
451 /* Stop the controller. */
452 reg = A37X0_SPI_READ(sc, A37X0_SPI_CONTROL);
453 A37X0_SPI_WRITE(sc, A37X0_SPI_CONTROL, reg & ~A37X0_SPI_CS_MASK);
454 A37X0_SPI_WRITE(sc, A37X0_SPI_INTR_MASK, 0);
455
456 /* Release the controller and wakeup the next thread waiting for it. */
457 sc->sc_flags = 0;
458 wakeup_one(dev);
459 A37X0_SPI_UNLOCK(sc);
460
461 return ((timeout == 0) ? EIO : 0);
462 }
463
464 static phandle_t
465 a37x0_spi_get_node(device_t bus, device_t dev)
466 {
467
468 return (ofw_bus_get_node(bus));
469 }
470
471 static device_method_t a37x0_spi_methods[] = {
472 /* Device interface */
473 DEVMETHOD(device_probe, a37x0_spi_probe),
474 DEVMETHOD(device_attach, a37x0_spi_attach),
475 DEVMETHOD(device_detach, a37x0_spi_detach),
476
477 /* SPI interface */
478 DEVMETHOD(spibus_transfer, a37x0_spi_transfer),
479
480 /* ofw_bus interface */
481 DEVMETHOD(ofw_bus_get_node, a37x0_spi_get_node),
482
483 DEVMETHOD_END
484 };
485
486 static devclass_t a37x0_spi_devclass;
487
488 static driver_t a37x0_spi_driver = {
489 "spi",
490 a37x0_spi_methods,
491 sizeof(struct a37x0_spi_softc),
492 };
493
494 DRIVER_MODULE(a37x0_spi, simplebus, a37x0_spi_driver, a37x0_spi_devclass, 0, 0);
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