xref: /netbsd-src/sys/arch/arm/sunxi/sun6i_spi.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: sun6i_spi.c,v 1.2 2018/02/01 14:50:36 jakllsch Exp $	*/
2 
3 /*
4  * Copyright (c) 2018 Jonathan A. Kollasch
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
20  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: sun6i_spi.c,v 1.2 2018/02/01 14:50:36 jakllsch Exp $");
31 
32 #include <sys/param.h>
33 #include <sys/device.h>
34 #include <sys/systm.h>
35 #include <sys/mutex.h>
36 #include <sys/bus.h>
37 #include <sys/intr.h>
38 #include <sys/kernel.h>
39 
40 #include <sys/bitops.h>
41 #include <dev/spi/spivar.h>
42 
43 #include <arm/sunxi/sun6i_spireg.h>
44 
45 #include <dev/fdt/fdtvar.h>
46 
47 #include <arm/fdt/arm_fdtvar.h>
48 
49 #define SPI_IER_DEFAULT (SPI_IER_TC_INT_EN | SPI_IER_TF_UDR_INT_EN | \
50 	SPI_IER_TF_OVF_INT_EN | SPI_IER_RF_UDR_INT_EN | SPI_IER_RF_OVF_INT_EN)
51 
52 struct sun6ispi_softc {
53 	device_t		sc_dev;
54 	bus_space_tag_t		sc_iot;
55 	bus_space_handle_t	sc_ioh;
56 	void			*sc_intrh;
57 	struct spi_controller	sc_spi;
58 	SIMPLEQ_HEAD(,spi_transfer) sc_q;
59 	struct spi_transfer	*sc_transfer;
60 	struct spi_chunk	*sc_wchunk;
61 	struct spi_chunk	*sc_rchunk;
62 	uint32_t		sc_TCR;
63 	u_int			sc_modclkrate;
64 	volatile bool		sc_running;
65 };
66 
67 static int sun6ispi_match(device_t, cfdata_t, void *);
68 static void sun6ispi_attach(device_t, device_t, void *);
69 
70 static int sun6ispi_configure(void *, int, int, int);
71 static int sun6ispi_transfer(void *, struct spi_transfer *);
72 
73 static void sun6ispi_start(struct sun6ispi_softc * const);
74 static int sun6ispi_intr(void *);
75 
76 static void sun6ispi_send(struct sun6ispi_softc * const);
77 static void sun6ispi_recv(struct sun6ispi_softc * const);
78 
79 CFATTACH_DECL_NEW(sun6i_spi, sizeof(struct sun6ispi_softc),
80     sun6ispi_match, sun6ispi_attach, NULL, NULL);
81 
82 static int
83 sun6ispi_match(device_t parent, cfdata_t cf, void *aux)
84 {
85 	const char * const compatible[] = {
86 		"allwinner,sun8i-h3-spi",
87 		NULL
88 	};
89 	struct fdt_attach_args * const faa = aux;
90 
91 	return of_match_compatible(faa->faa_phandle, compatible);
92 }
93 
94 static void
95 sun6ispi_attach(device_t parent, device_t self, void *aux)
96 {
97 	struct sun6ispi_softc * const sc = device_private(self);
98 	struct fdt_attach_args * const faa = aux;
99 	struct spibus_attach_args sba;
100 	struct fdtbus_reset *rst;
101 	struct clk *clk, *modclk;
102 	uint32_t gcr, isr;
103 	char intrstr[128];
104 
105 	aprint_naive("\n");
106 	aprint_normal(": SPI\n");
107 
108 	sc->sc_dev = self;
109 	sc->sc_iot = faa->faa_bst;
110 	SIMPLEQ_INIT(&sc->sc_q);
111 
112 	const int phandle = faa->faa_phandle;
113 	bus_addr_t addr;
114 	bus_size_t size;
115 
116 	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
117 		aprint_error_dev(sc->sc_dev, "missing 'reg' property\n");
118 		return;
119 	}
120 
121 	if (bus_space_map(sc->sc_iot, addr, size, 0, &sc->sc_ioh) != 0) {
122 		aprint_error_dev(sc->sc_dev, "unable to map device\n");
123 		return;
124 	}
125 
126 	if ((clk = fdtbus_clock_get_index(phandle, 0)) != NULL) {
127 		if (clk_enable(clk) != 0) {
128 			aprint_error_dev(sc->sc_dev, "couldn't enable clock\n");
129 			return;
130 		}
131 		device_printf(self, "%s ahb @ %uHz\n", __func__, clk_get_rate(clk));
132 	}
133 
134 	if ((modclk = fdtbus_clock_get(phandle, "mod")) != NULL) {
135 		/* 200MHz max on H3,H5 */
136 		if (clk_set_rate(modclk, 200000000) != 0) {
137 			aprint_error_dev(sc->sc_dev, "couldn't configure module clock\n");
138 			return;
139 		}
140 		if (clk_enable(modclk) != 0) {
141 			aprint_error_dev(sc->sc_dev, "couldn't enable module clock\n");
142 			return;
143 		}
144 		sc->sc_modclkrate = clk_get_rate(modclk);
145 		device_printf(self, "%s %uHz\n", __func__, sc->sc_modclkrate);
146 	}
147 
148 	if ((rst = fdtbus_reset_get_index(phandle, 0)) != NULL)
149 		if (fdtbus_reset_deassert(rst) != 0) {
150 			aprint_error(": couldn't de-assert reset\n");
151 			return;
152 		}
153 
154 	isr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_INT_STA);
155 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_INT_STA, isr);
156 
157 	if (!fdtbus_intr_str(phandle, 0, intrstr, sizeof(intrstr))) {
158 		aprint_error(": failed to decode interrupt\n");
159 		return;
160 	}
161 
162 	sc->sc_intrh = fdtbus_intr_establish(phandle, 0, IPL_VM, 0,
163 	    sun6ispi_intr, sc);
164 	if (sc->sc_intrh == NULL) {
165 		aprint_error_dev(sc->sc_dev, "unable to establish interrupt\n");
166 		return;
167 	}
168 	aprint_normal_dev(self, "interrupting on %s\n", intrstr);
169 
170 	gcr = SPI_GCR_SRST;
171 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_GCR, gcr);
172 	for (u_int i = 0; ; i++) {
173 		if (i >= 1000000) {
174 			aprint_error_dev(self, "reset timeout\n");
175 			return;
176 		}
177 		gcr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_GCR);
178 		if ((gcr & SPI_GCR_SRST) == 0)
179 			break;
180 		else
181 			DELAY(1);
182 	}
183 	gcr = SPI_GCR_TP_EN | SPI_GCR_MODE | SPI_GCR_EN;
184 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_GCR, gcr);
185 
186 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_IER, SPI_IER_DEFAULT);
187 
188 	sc->sc_spi.sct_cookie = sc;
189 	sc->sc_spi.sct_configure = sun6ispi_configure;
190 	sc->sc_spi.sct_transfer = sun6ispi_transfer;
191 	sc->sc_spi.sct_nslaves = 4;
192 
193 	sba.sba_controller = &sc->sc_spi;
194 
195 	(void) config_found_ia(self, "spibus", &sba, spibus_print);
196 }
197 
198 static int
199 sun6ispi_configure(void *cookie, int slave, int mode, int speed)
200 {
201 	struct sun6ispi_softc * const sc = cookie;
202 	uint32_t tcr, cctl;
203 
204 #if 0
205 	device_printf(sc->sc_dev, "%s slave %d mode %d speed %d\n", __func__, slave, mode, speed);
206 
207 	if (speed > 200000)
208 		speed = 200000;
209 #endif
210 
211 	tcr = SPI_TCR_SS_LEVEL | SPI_TCR_SPOL;
212 
213 	if (slave > 3)
214 		return EINVAL;
215 
216 	if (speed <= 0)
217 		return EINVAL;
218 
219 	switch (mode) {
220 	case SPI_MODE_0:
221 		tcr |= 0;
222 		break;
223 	case SPI_MODE_1:
224 		tcr |= SPI_TCR_CPHA;
225 		break;
226 	case SPI_MODE_2:
227 		tcr |= SPI_TCR_CPOL;
228 		break;
229 	case SPI_MODE_3:
230 		tcr |= SPI_TCR_CPHA|SPI_TCR_CPOL;
231 		break;
232 	default:
233 		return EINVAL;
234 	}
235 
236 	sc->sc_TCR = tcr;
237 
238 	if (speed < 3000 || speed > 200000000)
239 		return EINVAL;
240 
241 	if (speed > sc->sc_modclkrate / 2 || speed < sc->sc_modclkrate / 512) {
242 		for (cctl = 0; cctl <= __SHIFTOUT_MASK(SPI_CCTL_CDR1); cctl++) {
243 			if ((sc->sc_modclkrate / (1<<cctl)) <= speed)
244 				goto cdr1_found;
245 		}
246 		return EINVAL;
247 cdr1_found:
248 		cctl = __SHIFTIN(cctl, SPI_CCTL_CDR1);
249 	} else {
250 		cctl = howmany(sc->sc_modclkrate, 2 * speed) - 1;
251 		cctl = SPI_CCTL_DRS|__SHIFTIN(cctl, SPI_CCTL_CDR2);
252 	}
253 
254 	device_printf(sc->sc_dev, "%s CCTL 0x%08x\n", __func__, cctl);
255 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_CCTL, cctl);
256 
257 	return 0;
258 }
259 
260 static int
261 sun6ispi_transfer(void *cookie, struct spi_transfer *st)
262 {
263 	struct sun6ispi_softc * const sc = cookie;
264 	int s;
265 
266 	s = splbio();
267 	spi_transq_enqueue(&sc->sc_q, st);
268 	if (sc->sc_running == false) {
269 		sun6ispi_start(sc);
270 	}
271 	splx(s);
272 	return 0;
273 }
274 
275 static size_t
276 chunks_total_count(struct spi_transfer * st)
277 {
278 	struct spi_chunk *chunk = st->st_chunks;
279 	size_t len = 0;
280 
281 	do {
282 		len += chunk->chunk_count;
283 	} while ((chunk = chunk->chunk_next) != NULL);
284 
285 	return len;
286 }
287 
288 static void
289 sun6ispi_start(struct sun6ispi_softc * const sc)
290 {
291 	struct spi_transfer *st;
292 	uint32_t isr, tcr;
293 	size_t ctc;
294 
295 	//device_printf(sc->sc_dev, "%s\n", __func__);
296 	while ((st = spi_transq_first(&sc->sc_q)) != NULL) {
297 
298 		spi_transq_dequeue(&sc->sc_q);
299 
300 		KASSERT(sc->sc_transfer == NULL);
301 		sc->sc_transfer = st;
302 		sc->sc_rchunk = sc->sc_wchunk = st->st_chunks;
303 		sc->sc_running = true;
304 
305 		isr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_INT_STA);
306 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_INT_STA, isr);
307 
308 		//printf("%s fcr 0x%08x\n", __func__, bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_FCR));
309 
310 		ctc = chunks_total_count(st);
311 		//printf("%s total count %zu\n", __func__, ctc);
312 
313 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_BC, __SHIFTIN(ctc, SPI_BC_MBC));
314 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_TC, __SHIFTIN(ctc, SPI_TC_MWTC));
315 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_BCC, __SHIFTIN(ctc, SPI_BCC_STC));
316 
317 		KASSERT(st->st_slave <= 3);
318 		tcr = sc->sc_TCR | __SHIFTIN(st->st_slave, SPI_TCR_SS_SEL);
319 
320 		//device_printf(sc->sc_dev, "%s before TCR write\n", __func__);
321 		//bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_TCR, tcr);
322 
323 		sun6ispi_send(sc);
324 
325 		const uint32_t ier = SPI_IER_DEFAULT | SPI_IER_RF_RDY_INT_EN | SPI_IER_TX_ERQ_INT_EN;
326 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_IER, ier);
327 
328 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_TCR, tcr|SPI_TCR_XCH);
329 		//device_printf(sc->sc_dev, "%s after TCR write\n", __func__);
330 
331 		if (!cold)
332 			return;
333 
334 		//device_printf(sc->sc_dev, "%s cold\n", __func__);
335 
336 		int s = splbio();
337 		for (;;) {
338 			sun6ispi_intr(sc);
339 			if (ISSET(st->st_flags, SPI_F_DONE))
340 				break;
341 		}
342 		splx(s);
343 	}
344 
345 	sc->sc_running = false;
346 //	device_printf(sc->sc_dev, "%s finishes\n", __func__);
347 }
348 
349 static void
350 sun6ispi_send(struct sun6ispi_softc * const sc)
351 {
352 	uint8_t fd;
353 	uint32_t fsr;
354 	struct spi_chunk *chunk;
355 
356 	//device_printf(sc->sc_dev, "%s\n", __func__);
357 
358 	while ((chunk = sc->sc_wchunk) != NULL) {
359 		while (chunk->chunk_wresid) {
360 			fsr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_FSR);
361 			if (__SHIFTOUT(fsr, SPI_FSR_TF_CNT) >= 64) {
362 				//printf("%s fsr 0x%08x\n", __func__, fsr);
363 				return;
364 			}
365 			if (chunk->chunk_wptr) {
366 				fd = *chunk->chunk_wptr++;
367 			} else {
368 				fd = '\0';
369 			}
370 			//printf("%s fd %02x\n", __func__, fd);
371 			bus_space_write_1(sc->sc_iot, sc->sc_ioh, SPI_TXD, fd);
372 			chunk->chunk_wresid--;
373 		}
374 		sc->sc_wchunk = sc->sc_wchunk->chunk_next;
375 	}
376 }
377 
378 static void
379 sun6ispi_recv(struct sun6ispi_softc * const sc)
380 {
381 	uint8_t fd;
382 	uint32_t fsr;
383 	struct spi_chunk *chunk;
384 
385 	//device_printf(sc->sc_dev, "%s\n", __func__);
386 
387 	while ((chunk = sc->sc_rchunk) != NULL) {
388 		while (chunk->chunk_rresid) {
389 			fsr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_FSR);
390 			if (__SHIFTOUT(fsr, SPI_FSR_RF_CNT) == 0) {
391 				//printf("%s fsr 0x%08x\n", __func__, fsr);
392 				return;
393 			}
394 			fd = bus_space_read_1(sc->sc_iot, sc->sc_ioh, SPI_RXD);
395 			//printf("%s fd %02x\n", __func__, fd);
396 			if (chunk->chunk_rptr) {
397 				*chunk->chunk_rptr++ = fd;
398 			}
399 			chunk->chunk_rresid--;
400 		}
401 		sc->sc_rchunk = sc->sc_rchunk->chunk_next;
402 	}
403 }
404 
405 static int
406 sun6ispi_intr(void *cookie)
407 {
408 	struct sun6ispi_softc * const sc = cookie;
409 	struct spi_transfer *st;
410 	uint32_t isr;
411 
412 	isr = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SPI_INT_STA);
413 	bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_INT_STA, isr);
414 	//device_printf(sc->sc_dev, "%s ISR 0x%08x\n", __func__, isr);
415 
416 	if (ISSET(isr, SPI_ISR_RX_RDY)) {
417 		sun6ispi_recv(sc);
418 		sun6ispi_send(sc);
419 	}
420 
421 	if (ISSET(isr, SPI_ISR_TC)) {
422 		bus_space_write_4(sc->sc_iot, sc->sc_ioh, SPI_IER, SPI_IER_DEFAULT);
423 
424 		sc->sc_rchunk = sc->sc_wchunk = NULL;
425 		st = sc->sc_transfer;
426 		sc->sc_transfer = NULL;
427 		KASSERT(st != NULL);
428 		spi_done(st, 0);
429 		sc->sc_running = false;
430 	}
431 
432 	return isr;
433 }
434