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