rk_spi.c revision 1.6.4.2 1 /* $NetBSD: rk_spi.c,v 1.6.4.2 2021/06/17 04:46:18 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 2019 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Tobias Nygren.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: rk_spi.c,v 1.6.4.2 2021/06/17 04:46:18 thorpej Exp $");
34
35 #include <sys/param.h>
36 #include <sys/device.h>
37 #include <sys/systm.h>
38 #include <sys/bus.h>
39 #include <sys/intr.h>
40 #include <sys/kernel.h>
41 #include <sys/bitops.h>
42 #include <dev/spi/spivar.h>
43 #include <dev/fdt/fdtvar.h>
44 #include <arm/fdt/arm_fdtvar.h>
45
46 #define SPI_CTRLR0 0x00
47 #define SPI_CTRLR0_MTM __BIT(21)
48 #define SPI_CTRLR0_OPM __BIT(20)
49 #define SPI_CTRLR0_XFM __BITS(19, 18)
50 #define SPI_CTRLR0_FRF __BITS(17, 16)
51 #define SPI_CTRLR0_RSD __BITS(15, 14)
52 #define SPI_CTRLR0_BHT __BIT(13)
53 #define SPI_CTRLR0_FBM __BIT(12)
54 #define SPI_CTRLR0_EM __BIT(11)
55 #define SPI_CTRLR0_RW __BIT(10)
56 #define SPI_CTRLR0_CSM __BITS(9, 8)
57 #define SPI_CTRLR0_SCPOL __BIT(7)
58 #define SPI_CTRLR0_SCPH __BIT(6)
59 #define SPI_CTRLR0_CFS __BITS(5, 2)
60 #define SPI_CTRLR0_DFS __BITS(1, 0)
61 #define SPI_CTRLR0_DFS_4BIT 0x0
62 #define SPI_CTRLR0_DFS_8BIT 0x1
63 #define SPI_CTRLR0_DFS_16BIT 0x2
64
65 #define SPI_CTRLR1 0x04
66 #define SPI_CTRLR1_NDM __BITS(15, 0)
67
68 #define SPI_ENR 0x08
69 #define SPI_ENR_ENR __BIT(0)
70
71 #define SPI_SER 0x0c
72 #define SPI_SER_SER1 __BIT(1)
73 #define SPI_SER_SER0 __BIT(0)
74
75 #define SPI_BAUDR 0x10
76 #define SPI_BAUDR_BAUDR __BITS(15, 0)
77
78 #define SPI_TXFTLR 0x14
79 #define SPI_TXFTLR_TXFLTR __BITS(4, 0)
80
81 #define SPI_RXFTLR 0x18
82 #define SPI_RXFLTR_RXFLTR __BITS(4, 0)
83
84 #define SPI_TXFLR 0x1c
85 #define SPI_TXFLR_TXFLR __BITS(5, 0)
86
87 #define SPI_RXFLR 0x20
88 #define SPI_RXFLR_RXFLR __BITS(5, 0)
89
90 #define SPI_SR 0x24
91 #define SPI_SR_RFF __BIT(4)
92 #define SPI_SR_RFE __BIT(3)
93 #define SPI_SR_TFE __BIT(2)
94 #define SPI_SR_TFF __BIT(1)
95 #define SPI_SR_BSF __BIT(0)
96
97 #define SPI_IPR 0x28
98 #define SPI_IPR_IPR __BIT(0)
99
100 #define SPI_IMR 0x2c
101 #define SPI_IMR_RFFIM __BIT(4)
102 #define SPI_IMR_RFOIM __BIT(3)
103 #define SPI_IMR_RFUIM __BIT(2)
104 #define SPI_IMR_TFOIM __BIT(1)
105 #define SPI_IMR_TFEIM __BIT(0)
106
107 #define SPI_ISR 0x30
108 #define SPI_ISR_RFFIS __BIT(4)
109 #define SPI_ISR_RFOIS __BIT(3)
110 #define SPI_ISR_RFUIS __BIT(2)
111 #define SPI_ISR_TFOIS __BIT(1)
112 #define SPI_ISR_TFEIS __BIT(0)
113
114 #define SPI_RISR 0x34
115 #define SPI_RISR_RFFRIS __BIT(4)
116 #define SPI_RISR_RFORIS __BIT(3)
117 #define SPI_RISR_RFURIS __BIT(2)
118 #define SPI_RISR_TFORIS __BIT(1)
119 #define SPI_RISR_TFERIS __BIT(0)
120
121 #define SPI_ICR 0x38
122 #define SPI_ICR_CTFOI __BIT(3)
123 #define SPI_ICR_CRFOI __BIT(2)
124 #define SPI_ICR_CRFUI __BIT(1)
125 #define SPI_ICR_CCI __BIT(0)
126 #define SPI_ICR_ALL __BITS(3, 0)
127
128 #define SPI_DMACR 0x3c
129 #define SPI_DMACR_TDE __BIT(1)
130 #define SPI_DMACR_RDE __BIT(0)
131
132 #define SPI_DMATDLR 0x40
133 #define SPI_DMATDLR_TDL __BITS(4, 0)
134
135 #define SPI_DMARDLR 0x44
136 #define SPI_DMARDLR_RDL __BITS(4, 0)
137
138 #define SPI_TXDR 0x400
139 #define SPI_TXDR_TXDR __BITS(15, 0)
140
141 #define SPI_RXDR 0x800
142 #define SPI_RXDR_RXDR __BITS(15, 0)
143
144 #define SPI_FIFOLEN 32
145
146 static const struct device_compatible_entry compat_data[] = {
147 { .compat = "rockchip,rk3066-spi" },
148 { .compat = "rockchip,rk3328-spi" },
149 { .compat = "rockchip,rk3399-spi" },
150 DEVICE_COMPAT_EOL
151 };
152
153 struct rk_spi_softc {
154 device_t sc_dev;
155 bus_space_tag_t sc_bst;
156 bus_space_handle_t sc_bsh;
157 void *sc_ih;
158 u_int sc_spi_freq;
159 struct spi_controller sc_spi;
160 SIMPLEQ_HEAD(,spi_transfer) sc_q;
161 struct spi_transfer *sc_transfer;
162 struct spi_chunk *sc_rchunk, *sc_wchunk;
163 volatile bool sc_running;
164 };
165
166 #define SPIREG_READ(sc, reg) \
167 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
168 #define SPIREG_WRITE(sc, reg, val) \
169 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
170
171 static int rk_spi_match(device_t, cfdata_t, void *);
172 static void rk_spi_attach(device_t, device_t, void *);
173
174 static int rk_spi_configure(void *, int, int, int);
175 static int rk_spi_transfer(void *, struct spi_transfer *);
176
177 static void rk_spi_txfifo_fill(struct rk_spi_softc * const, size_t);
178 static void rk_spi_rxfifo_drain(struct rk_spi_softc * const, size_t);
179 static void rk_spi_rxtx(struct rk_spi_softc * const);
180 static void rk_spi_set_interrupt_mask(struct rk_spi_softc * const);
181 static void rk_spi_start(struct rk_spi_softc * const);
182 static int rk_spi_intr(void *);
183
184 CFATTACH_DECL_NEW(rk_spi, sizeof(struct rk_spi_softc),
185 rk_spi_match, rk_spi_attach, NULL, NULL);
186
187 static int
188 rk_spi_match(device_t parent, cfdata_t cf, void *aux)
189 {
190 struct fdt_attach_args * const faa = aux;
191
192 return of_compatible_match(faa->faa_phandle, compat_data);
193 }
194
195 static void
196 rk_spi_attach(device_t parent, device_t self, void *aux)
197 {
198 struct rk_spi_softc * const sc = device_private(self);
199 struct fdt_attach_args * const faa = aux;
200 const int phandle = faa->faa_phandle;
201 bus_addr_t addr;
202 bus_size_t size;
203 struct clk *sclk, *pclk;
204 char intrstr[128];
205
206 sc->sc_dev = self;
207 sc->sc_bst = faa->faa_bst;
208 SIMPLEQ_INIT(&sc->sc_q);
209
210 if ((sclk = fdtbus_clock_get(phandle, "spiclk")) == NULL
211 || clk_enable(sclk) != 0) {
212 aprint_error(": couldn't enable sclk\n");
213 return;
214 }
215
216 if ((pclk = fdtbus_clock_get(phandle, "apb_pclk")) == NULL
217 || clk_enable(pclk) != 0) {
218 aprint_error(": couldn't enable pclk\n");
219 return;
220 }
221
222 sc->sc_spi_freq = clk_get_rate(sclk);
223
224 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0
225 || bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) {
226 aprint_error(": couldn't map registers\n");
227 return;
228 }
229
230 SPIREG_WRITE(sc, SPI_ENR, 0);
231 SPIREG_WRITE(sc, SPI_IMR, 0);
232
233 if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
234 aprint_error(": failed to decode interrupt\n");
235 return;
236 }
237
238 sc->sc_ih = fdtbus_intr_establish_xname(phandle, 0, IPL_VM, 0,
239 rk_spi_intr, sc, device_xname(self));
240 if (sc->sc_ih == NULL) {
241 aprint_error(": unable to establish interrupt\n");
242 return;
243 }
244
245 aprint_naive("\n");
246 aprint_normal(": SPI\n");
247 aprint_normal_dev(self, "interrupting on %s\n", intrstr);
248
249 sc->sc_spi.sct_cookie = sc;
250 sc->sc_spi.sct_configure = rk_spi_configure;
251 sc->sc_spi.sct_transfer = rk_spi_transfer;
252 sc->sc_spi.sct_nslaves = 2;
253
254 fdtbus_register_spi_controller(&sc->sc_spi, phandle);
255
256 struct spibus_attach_args sba = {
257 .sba_controller = &sc->sc_spi,
258 };
259 config_found(self, &sba, spibus_print,
260 CFARG_DEVHANDLE, device_handle(self),
261 CFARG_EOL);
262 }
263
264 static int
265 rk_spi_configure(void *cookie, int slave, int mode, int speed)
266 {
267 struct rk_spi_softc * const sc = cookie;
268 uint32_t ctrlr0;
269 uint16_t divider;
270
271 divider = (sc->sc_spi_freq / speed) & ~1;
272 if (divider < 2) {
273 aprint_error_dev(sc->sc_dev,
274 "spi_clk %u is too low for speed %u, using speed %u\n",
275 sc->sc_spi_freq, speed, sc->sc_spi_freq / 2);
276 divider = 2;
277 }
278
279 if (slave >= sc->sc_spi.sct_nslaves)
280 return EINVAL;
281
282 ctrlr0 = SPI_CTRLR0_BHT | __SHIFTIN(SPI_CTRLR0_DFS_8BIT, SPI_CTRLR0_DFS);
283
284 switch (mode) {
285 case SPI_MODE_0:
286 ctrlr0 |= 0;
287 break;
288 case SPI_MODE_1:
289 ctrlr0 |= SPI_CTRLR0_SCPH;
290 break;
291 case SPI_MODE_2:
292 ctrlr0 |= SPI_CTRLR0_SCPOL;
293 break;
294 case SPI_MODE_3:
295 ctrlr0 |= SPI_CTRLR0_SCPH | SPI_CTRLR0_SCPOL;
296 break;
297 default:
298 return EINVAL;
299 }
300
301 SPIREG_WRITE(sc, SPI_ENR, 0);
302 SPIREG_WRITE(sc, SPI_SER, 0);
303 SPIREG_WRITE(sc, SPI_CTRLR0, ctrlr0);
304 SPIREG_WRITE(sc, SPI_BAUDR, divider);
305
306 SPIREG_WRITE(sc, SPI_DMACR, 0);
307 SPIREG_WRITE(sc, SPI_DMATDLR, 0);
308 SPIREG_WRITE(sc, SPI_DMARDLR, 0);
309
310 SPIREG_WRITE(sc, SPI_IPR, 0);
311 SPIREG_WRITE(sc, SPI_IMR, 0);
312 SPIREG_WRITE(sc, SPI_ICR, SPI_ICR_ALL);
313
314 SPIREG_WRITE(sc, SPI_ENR, 1);
315
316 return 0;
317 }
318
319 static int
320 rk_spi_transfer(void *cookie, struct spi_transfer *st)
321 {
322 struct rk_spi_softc * const sc = cookie;
323 int s;
324
325 s = splbio();
326 spi_transq_enqueue(&sc->sc_q, st);
327 if (sc->sc_running == false) {
328 rk_spi_start(sc);
329 }
330 splx(s);
331
332 return 0;
333 }
334
335 static void
336 rk_spi_txfifo_fill(struct rk_spi_softc * const sc, size_t maxlen)
337 {
338 struct spi_chunk *chunk = sc->sc_wchunk;
339 size_t len;
340 uint8_t b;
341
342 if (chunk == NULL)
343 return;
344
345 len = MIN(maxlen, chunk->chunk_wresid);
346 chunk->chunk_wresid -= len;
347 while (len--) {
348 if (chunk->chunk_wptr) {
349 b = *chunk->chunk_wptr++;
350 } else {
351 b = 0;
352 }
353 bus_space_write_1(sc->sc_bst, sc->sc_bsh, SPI_TXDR, b);
354 }
355 if (sc->sc_wchunk->chunk_wresid == 0) {
356 sc->sc_wchunk = sc->sc_wchunk->chunk_next;
357 }
358 }
359
360 static void
361 rk_spi_rxfifo_drain(struct rk_spi_softc * const sc, size_t maxlen)
362 {
363 struct spi_chunk *chunk = sc->sc_rchunk;
364 size_t len;
365 uint8_t b;
366
367 if (chunk == NULL)
368 return;
369
370 len = MIN(maxlen, chunk->chunk_rresid);
371 chunk->chunk_rresid -= len;
372
373 while (len--) {
374 b = bus_space_read_1(sc->sc_bst, sc->sc_bsh, SPI_RXDR);
375 if (chunk->chunk_rptr) {
376 *chunk->chunk_rptr++ = b;
377 }
378 }
379 if (sc->sc_rchunk->chunk_rresid == 0) {
380 sc->sc_rchunk = sc->sc_rchunk->chunk_next;
381 }
382 }
383
384 static void
385 rk_spi_rxtx(struct rk_spi_softc * const sc)
386 {
387 bool again;
388 uint32_t reg;
389 size_t avail;
390
391 /* Service both FIFOs until no more progress can be made. */
392 again = true;
393 while (again) {
394 again = false;
395 reg = SPIREG_READ(sc, SPI_RXFLR);
396 avail = __SHIFTOUT(reg, SPI_RXFLR_RXFLR);
397 if (avail > 0) {
398 KASSERT(sc->sc_rchunk != NULL);
399 rk_spi_rxfifo_drain(sc, avail);
400 again = true;
401 }
402 reg = SPIREG_READ(sc, SPI_TXFLR);
403 avail = SPI_FIFOLEN - __SHIFTOUT(reg, SPI_TXFLR_TXFLR);
404 if (avail > 0 && sc->sc_wchunk != NULL) {
405 rk_spi_txfifo_fill(sc, avail);
406 again = true;
407 }
408 }
409 }
410
411 static void
412 rk_spi_set_interrupt_mask(struct rk_spi_softc * const sc)
413 {
414 uint32_t imr = SPI_IMR_RFOIM | SPI_IMR_RFUIM | SPI_IMR_TFOIM;
415 int len;
416
417 /*
418 * Delay rx interrupts until the FIFO has the # of bytes we'd
419 * ideally like to receive, or FIFO is half full.
420 */
421 len = sc->sc_rchunk != NULL
422 ? MIN(sc->sc_rchunk->chunk_rresid, SPI_FIFOLEN / 2) : 0;
423 if (len > 0) {
424 SPIREG_WRITE(sc, SPI_RXFTLR, len - 1);
425 imr |= SPI_IMR_RFFIM;
426 }
427
428 /*
429 * Delay tx interrupts until the FIFO can accept the # of bytes we'd
430 * ideally like to transmit, or the FIFO is half empty.
431 */
432 len = sc->sc_wchunk != NULL
433 ? MIN(sc->sc_wchunk->chunk_wresid, SPI_FIFOLEN / 2) : 0;
434 if (len > 0) {
435 SPIREG_WRITE(sc, SPI_TXFTLR, SPI_FIFOLEN - len);
436 imr |= SPI_IMR_TFEIM;
437 }
438
439 /* If xfer is done, then interrupt as soon as the tx fifo is empty. */
440 if (!ISSET(imr, (SPI_IMR_RFFIM | SPI_IMR_TFEIM))) {
441 SPIREG_WRITE(sc, SPI_TXFTLR, 0);
442 imr |= SPI_IMR_TFEIM;
443 }
444
445 SPIREG_WRITE(sc, SPI_IMR, imr);
446 }
447
448 static void
449 rk_spi_start(struct rk_spi_softc * const sc)
450 {
451 struct spi_transfer *st;
452
453 while ((st = spi_transq_first(&sc->sc_q)) != NULL) {
454 spi_transq_dequeue(&sc->sc_q);
455 KASSERT(sc->sc_transfer == NULL);
456 sc->sc_transfer = st;
457 sc->sc_rchunk = sc->sc_wchunk = st->st_chunks;
458 sc->sc_running = true;
459
460 KASSERT(st->st_slave < sc->sc_spi.sct_nslaves);
461 SPIREG_WRITE(sc, SPI_SER, 1 << st->st_slave);
462
463 rk_spi_rxtx(sc);
464 rk_spi_set_interrupt_mask(sc);
465
466 if (!cold)
467 return;
468
469 for (;;) {
470 (void) rk_spi_intr(sc);
471 if (ISSET(st->st_flags, SPI_F_DONE))
472 break;
473 }
474 }
475 sc->sc_running = false;
476 }
477
478 static int
479 rk_spi_intr(void *cookie)
480 {
481 struct rk_spi_softc * const sc = cookie;
482 struct spi_transfer *st;
483 uint32_t isr;
484 uint32_t sr;
485 uint32_t icr = SPI_ICR_CCI;
486
487 isr = SPIREG_READ(sc, SPI_ISR);
488 if (!isr)
489 return 0;
490
491 if (ISSET(isr, SPI_ISR_RFOIS)) {
492 device_printf(sc->sc_dev, "RXFIFO overflow\n");
493 icr |= SPI_ICR_CRFOI;
494 }
495 if (ISSET(isr, SPI_ISR_RFUIS)) {
496 device_printf(sc->sc_dev, "RXFIFO underflow\n");
497 icr |= SPI_ICR_CRFUI;
498 }
499 if (ISSET(isr, SPI_ISR_TFOIS)) {
500 device_printf(sc->sc_dev, "TXFIFO overflow\n");
501 icr |= SPI_ICR_CTFOI;
502 }
503
504 rk_spi_rxtx(sc);
505
506 if (sc->sc_rchunk == NULL && sc->sc_wchunk == NULL) {
507 do {
508 sr = SPIREG_READ(sc, SPI_SR);
509 } while (ISSET(sr, SPI_SR_BSF));
510 SPIREG_WRITE(sc, SPI_IMR, 0);
511 SPIREG_WRITE(sc, SPI_SER, 0);
512 st = sc->sc_transfer;
513 sc->sc_transfer = NULL;
514 KASSERT(st != NULL);
515 spi_done(st, 0);
516 sc->sc_running = false;
517 } else {
518 rk_spi_set_interrupt_mask(sc);
519 }
520
521 SPIREG_WRITE(sc, SPI_ICR, icr);
522
523 return 1;
524 }
525