xref: /freebsd/sys/dev/spibus/controller/rockchip/rk_spi.c (revision 02e9120893770924227138ba49df1edb3896112a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
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 THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23  * 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/param.h>
29 #include <sys/systm.h>
30 #include <sys/bus.h>
31 #include <sys/kernel.h>
32 #include <sys/lock.h>
33 #include <sys/module.h>
34 #include <sys/mutex.h>
35 #include <sys/rman.h>
36 #include <sys/resource.h>
37 #include <machine/bus.h>
38 
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41 
42 #include <dev/spibus/spi.h>
43 #include <dev/spibus/spibusvar.h>
44 
45 #include <dev/extres/clk/clk.h>
46 #include <dev/extres/hwreset/hwreset.h>
47 
48 #include "spibus_if.h"
49 
50 #define	RK_SPI_CTRLR0		0x0000
51 #define		CTRLR0_OPM_MASTER	(0 << 20)
52 #define		CTRLR0_XFM_TR		(0 << 18)
53 #define		CTRLR0_FRF_MOTO		(0 << 16)
54 #define		CTRLR0_BHT_8BIT		(1 << 13)
55 #define		CTRLR0_EM_BIG		(1 << 11)
56 #define		CTRLR0_SSD_ONE		(1 << 10)
57 #define		CTRLR0_SCPOL		(1 <<  7)
58 #define		CTRLR0_SCPH		(1 <<  6)
59 #define		CTRLR0_DFS_8BIT		(1 <<  0)
60 #define	RK_SPI_CTRLR1		0x0004
61 #define	RK_SPI_ENR		0x0008
62 #define	RK_SPI_SER		0x000c
63 #define	RK_SPI_BAUDR		0x0010
64 #define	RK_SPI_TXFTLR		0x0014
65 #define	RK_SPI_RXFTLR		0x0018
66 #define	RK_SPI_TXFLR		0x001c
67 #define	RK_SPI_RXFLR		0x0020
68 #define	RK_SPI_SR		0x0024
69 #define		SR_BUSY			(1 <<  0)
70 #define	RK_SPI_IPR		0x0028
71 #define	RK_SPI_IMR		0x002c
72 #define		IMR_RFFIM		(1 <<  4)
73 #define		IMR_TFEIM		(1 <<  0)
74 #define	RK_SPI_ISR		0x0030
75 #define		ISR_RFFIS		(1 <<  4)
76 #define		ISR_TFEIS		(1 <<  0)
77 #define	RK_SPI_RISR		0x0034
78 #define	RK_SPI_ICR		0x0038
79 #define	RK_SPI_DMACR		0x003c
80 #define	RK_SPI_DMATDLR		0x0040
81 #define	RK_SPI_DMARDLR		0x0044
82 #define	RK_SPI_TXDR		0x0400
83 #define	RK_SPI_RXDR		0x0800
84 
85 #define	CS_MAX			1
86 
87 static struct ofw_compat_data compat_data[] = {
88 	{ "rockchip,rk3328-spi",		1 },
89 	{ "rockchip,rk3399-spi",		1 },
90 	{ "rockchip,rk3568-spi",		1 },
91 	{ NULL,					0 }
92 };
93 
94 static struct resource_spec rk_spi_spec[] = {
95 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
96 	{ SYS_RES_IRQ,		0,	RF_ACTIVE | RF_SHAREABLE },
97 	{ -1, 0 }
98 };
99 
100 struct rk_spi_softc {
101 	device_t	dev;
102 	device_t	spibus;
103 	struct resource	*res[2];
104 	struct mtx	mtx;
105 	clk_t		clk_apb;
106 	clk_t		clk_spi;
107 	void *		intrhand;
108 	int		transfer;
109 	uint32_t	fifo_size;
110 	uint64_t	max_freq;
111 
112 	uint32_t	intreg;
113 	uint8_t		*rxbuf;
114 	uint32_t	rxidx;
115 	uint8_t		*txbuf;
116 	uint32_t	txidx;
117 	uint32_t	txlen;
118 	uint32_t	rxlen;
119 };
120 
121 #define	RK_SPI_LOCK(sc)			mtx_lock(&(sc)->mtx)
122 #define	RK_SPI_UNLOCK(sc)		mtx_unlock(&(sc)->mtx)
123 #define	RK_SPI_READ_4(sc, reg)		bus_read_4((sc)->res[0], (reg))
124 #define	RK_SPI_WRITE_4(sc, reg, val)	bus_write_4((sc)->res[0], (reg), (val))
125 
126 static int rk_spi_probe(device_t dev);
127 static int rk_spi_attach(device_t dev);
128 static int rk_spi_detach(device_t dev);
129 static void rk_spi_intr(void *arg);
130 
131 static void
132 rk_spi_enable_chip(struct rk_spi_softc *sc, int enable)
133 {
134 
135 	RK_SPI_WRITE_4(sc, RK_SPI_ENR, enable ? 1 : 0);
136 }
137 
138 static int
139 rk_spi_set_cs(struct rk_spi_softc *sc, uint32_t cs, bool active)
140 {
141 	uint32_t reg;
142 
143 	if (cs & SPIBUS_CS_HIGH) {
144 		device_printf(sc->dev, "SPIBUS_CS_HIGH is not supported\n");
145 		return (EINVAL);
146 	}
147 
148 	if (cs > CS_MAX)
149 		return (EINVAL);
150 
151 	reg = RK_SPI_READ_4(sc, RK_SPI_SER);
152 	if (active)
153 		reg |= (1 << cs);
154 	else
155 		reg &= ~(1 << cs);
156 	RK_SPI_WRITE_4(sc, RK_SPI_SER, reg);
157 
158 	return (0);
159 }
160 
161 static void
162 rk_spi_hw_setup(struct rk_spi_softc *sc, uint32_t mode, uint32_t freq)
163 {
164 	uint32_t cr0;
165 	uint32_t div;
166 
167 	cr0 =  CTRLR0_OPM_MASTER | CTRLR0_XFM_TR | CTRLR0_FRF_MOTO |
168 	    CTRLR0_BHT_8BIT | CTRLR0_EM_BIG | CTRLR0_SSD_ONE |
169 	    CTRLR0_DFS_8BIT;
170 
171 	if (mode & SPIBUS_MODE_CPHA)
172 		cr0 |= CTRLR0_SCPH;
173 	if (mode & SPIBUS_MODE_CPOL)
174 		cr0 |= CTRLR0_SCPOL;
175 
176 	/* minimum divider is 2 */
177 	if (sc->max_freq < freq*2) {
178 		clk_set_freq(sc->clk_spi, 2 * freq, CLK_SET_ROUND_DOWN);
179 		clk_get_freq(sc->clk_spi, &sc->max_freq);
180 	}
181 
182 	div = ((sc->max_freq + freq - 1) / freq);
183 	div = (div + 1) & 0xfffe;
184 	RK_SPI_WRITE_4(sc, RK_SPI_BAUDR, div);
185 
186 	RK_SPI_WRITE_4(sc, RK_SPI_CTRLR0, cr0);
187 }
188 
189 static uint32_t
190 rk_spi_fifo_size(struct rk_spi_softc *sc)
191 {
192 	uint32_t txftlr, reg;
193 
194 	for (txftlr = 2; txftlr < 32; txftlr++) {
195 		RK_SPI_WRITE_4(sc, RK_SPI_TXFTLR, txftlr);
196 		reg = RK_SPI_READ_4(sc, RK_SPI_TXFTLR);
197 		if (reg != txftlr)
198 			break;
199 	}
200 	RK_SPI_WRITE_4(sc, RK_SPI_TXFTLR, 0);
201 
202 	if (txftlr == 31)
203 		return 0;
204 
205 	return txftlr;
206 }
207 
208 static void
209 rk_spi_empty_rxfifo(struct rk_spi_softc *sc)
210 {
211 	uint32_t rxlevel;
212 	rxlevel = RK_SPI_READ_4(sc, RK_SPI_RXFLR);
213 	while (sc->rxidx < sc->rxlen &&
214 	    (rxlevel-- > 0)) {
215 		sc->rxbuf[sc->rxidx++] = (uint8_t)RK_SPI_READ_4(sc, RK_SPI_RXDR);
216 	}
217 }
218 
219 static void
220 rk_spi_fill_txfifo(struct rk_spi_softc *sc)
221 {
222 	uint32_t txlevel;
223 	txlevel = RK_SPI_READ_4(sc, RK_SPI_TXFLR);
224 
225 	while (sc->txidx < sc->txlen && txlevel < sc->fifo_size) {
226 		RK_SPI_WRITE_4(sc, RK_SPI_TXDR, sc->txbuf[sc->txidx++]);
227 		txlevel++;
228 	}
229 
230 	if (sc->txidx != sc->txlen)
231 		sc->intreg |= (IMR_TFEIM  | IMR_RFFIM);
232 }
233 
234 static int
235 rk_spi_xfer_buf(struct rk_spi_softc *sc, void *rxbuf, void *txbuf, uint32_t len)
236 {
237 	int err;
238 
239 	if (len == 0)
240 		return (0);
241 
242 	sc->rxbuf = rxbuf;
243 	sc->rxlen = len;
244 	sc->rxidx = 0;
245 	sc->txbuf = txbuf;
246 	sc->txlen = len;
247 	sc->txidx = 0;
248 	sc->intreg = 0;
249 	rk_spi_fill_txfifo(sc);
250 
251 	RK_SPI_WRITE_4(sc, RK_SPI_IMR, sc->intreg);
252 
253 	err = 0;
254 	while (err == 0 && sc->intreg != 0)
255 		err = msleep(sc, &sc->mtx, 0, "rk_spi", 10 * hz);
256 
257 	while (err == 0 && sc->rxidx != sc->txidx) {
258 		/* read residual data from RX fifo */
259 		rk_spi_empty_rxfifo(sc);
260 	}
261 
262 	if (sc->rxidx != sc->rxlen || sc->txidx != sc->txlen)
263 		err = EIO;
264 
265 	return (err);
266 }
267 
268 static int
269 rk_spi_probe(device_t dev)
270 {
271 	if (!ofw_bus_status_okay(dev))
272 		return (ENXIO);
273 
274 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
275 		return (ENXIO);
276 
277 	device_set_desc(dev, "Rockchip SPI");
278 	return (BUS_PROBE_DEFAULT);
279 }
280 
281 static int
282 rk_spi_attach(device_t dev)
283 {
284 	struct rk_spi_softc *sc;
285 	int error;
286 
287 	sc = device_get_softc(dev);
288 	sc->dev = dev;
289 
290 	mtx_init(&sc->mtx, device_get_nameunit(dev), NULL, MTX_DEF);
291 
292 	if (bus_alloc_resources(dev, rk_spi_spec, sc->res) != 0) {
293 		device_printf(dev, "cannot allocate resources for device\n");
294 		error = ENXIO;
295 		goto fail;
296 	}
297 
298 	if (bus_setup_intr(dev, sc->res[1],
299 	    INTR_TYPE_MISC | INTR_MPSAFE, NULL, rk_spi_intr, sc,
300 	    &sc->intrhand)) {
301 		bus_release_resources(dev, rk_spi_spec, sc->res);
302 		device_printf(dev, "cannot setup interrupt handler\n");
303 		return (ENXIO);
304 	}
305 
306 	/* Activate the module clock. */
307 	error = clk_get_by_ofw_name(dev, 0, "apb_pclk", &sc->clk_apb);
308 	if (error != 0) {
309 		device_printf(dev, "cannot get apb_pclk clock\n");
310 		goto fail;
311 	}
312 	error = clk_get_by_ofw_name(dev, 0, "spiclk", &sc->clk_spi);
313 	if (error != 0) {
314 		device_printf(dev, "cannot get spiclk clock\n");
315 		goto fail;
316 	}
317 	error = clk_enable(sc->clk_apb);
318 	if (error != 0) {
319 		device_printf(dev, "cannot enable ahb clock\n");
320 		goto fail;
321 	}
322 	error = clk_enable(sc->clk_spi);
323 	if (error != 0) {
324 		device_printf(dev, "cannot enable spiclk clock\n");
325 		goto fail;
326 	}
327 	clk_get_freq(sc->clk_spi, &sc->max_freq);
328 
329 	sc->fifo_size = rk_spi_fifo_size(sc);
330 	if (sc->fifo_size == 0) {
331 		device_printf(dev, "failed to get fifo size\n");
332 		goto fail;
333 	}
334 
335 	sc->spibus = device_add_child(dev, "spibus", -1);
336 
337 	RK_SPI_WRITE_4(sc, RK_SPI_IMR, 0);
338 	RK_SPI_WRITE_4(sc, RK_SPI_TXFTLR, sc->fifo_size/2 - 1);
339 	RK_SPI_WRITE_4(sc, RK_SPI_RXFTLR, sc->fifo_size/2 - 1);
340 
341 	return (bus_generic_attach(dev));
342 
343 fail:
344 	rk_spi_detach(dev);
345 	return (error);
346 }
347 
348 static int
349 rk_spi_detach(device_t dev)
350 {
351 	struct rk_spi_softc *sc;
352 
353 	sc = device_get_softc(dev);
354 
355 	bus_generic_detach(sc->dev);
356 	if (sc->spibus != NULL)
357 		device_delete_child(dev, sc->spibus);
358 
359 	if (sc->clk_spi != NULL)
360 		clk_release(sc->clk_spi);
361 	if (sc->clk_apb)
362 		clk_release(sc->clk_apb);
363 
364 	if (sc->intrhand != NULL)
365 		bus_teardown_intr(sc->dev, sc->res[1], sc->intrhand);
366 
367 	bus_release_resources(dev, rk_spi_spec, sc->res);
368 	mtx_destroy(&sc->mtx);
369 
370 	return (0);
371 }
372 
373 static void
374 rk_spi_intr(void *arg)
375 {
376 	struct rk_spi_softc *sc;
377 	uint32_t intreg, isr;
378 
379 	sc = arg;
380 
381 	RK_SPI_LOCK(sc);
382 	intreg = RK_SPI_READ_4(sc, RK_SPI_IMR);
383 	isr = RK_SPI_READ_4(sc, RK_SPI_ISR);
384 	RK_SPI_WRITE_4(sc, RK_SPI_ICR, isr);
385 
386 	if (isr & ISR_RFFIS)
387 		rk_spi_empty_rxfifo(sc);
388 
389 	if (isr & ISR_TFEIS)
390 		rk_spi_fill_txfifo(sc);
391 
392 	/* no bytes left, disable interrupt */
393 	if (sc->txidx == sc->txlen) {
394 		sc->intreg = 0;
395 		wakeup(sc);
396 	}
397 
398 	if (sc->intreg != intreg) {
399 		(void)RK_SPI_WRITE_4(sc, RK_SPI_IMR, sc->intreg);
400 		(void)RK_SPI_READ_4(sc, RK_SPI_IMR);
401 	}
402 
403 	RK_SPI_UNLOCK(sc);
404 }
405 
406 static phandle_t
407 rk_spi_get_node(device_t bus, device_t dev)
408 {
409 
410 	return ofw_bus_get_node(bus);
411 }
412 
413 static int
414 rk_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
415 {
416 	struct rk_spi_softc *sc;
417 	uint32_t cs, mode, clock;
418 	int err = 0;
419 
420 	sc = device_get_softc(dev);
421 
422 	spibus_get_cs(child, &cs);
423 	spibus_get_clock(child, &clock);
424 	spibus_get_mode(child, &mode);
425 
426 	RK_SPI_LOCK(sc);
427 	rk_spi_hw_setup(sc, mode, clock);
428 	rk_spi_enable_chip(sc, 1);
429 	err = rk_spi_set_cs(sc, cs, true);
430 	if (err != 0) {
431 		rk_spi_enable_chip(sc, 0);
432 		RK_SPI_UNLOCK(sc);
433 		return (err);
434 	}
435 
436 	/* Transfer command then data bytes. */
437 	err = 0;
438 	if (cmd->tx_cmd_sz > 0)
439 		err = rk_spi_xfer_buf(sc, cmd->rx_cmd, cmd->tx_cmd,
440 		    cmd->tx_cmd_sz);
441 	if (cmd->tx_data_sz > 0 && err == 0)
442 		err = rk_spi_xfer_buf(sc, cmd->rx_data, cmd->tx_data,
443 		    cmd->tx_data_sz);
444 
445 	rk_spi_set_cs(sc, cs, false);
446 	rk_spi_enable_chip(sc, 0);
447 	RK_SPI_UNLOCK(sc);
448 
449 	return (err);
450 }
451 
452 static device_method_t rk_spi_methods[] = {
453 	/* Device interface */
454 	DEVMETHOD(device_probe,		rk_spi_probe),
455 	DEVMETHOD(device_attach,	rk_spi_attach),
456 	DEVMETHOD(device_detach,	rk_spi_detach),
457 
458         /* spibus_if  */
459 	DEVMETHOD(spibus_transfer,	rk_spi_transfer),
460 
461         /* ofw_bus_if */
462 	DEVMETHOD(ofw_bus_get_node,	rk_spi_get_node),
463 
464 	DEVMETHOD_END
465 };
466 
467 static driver_t rk_spi_driver = {
468 	"spi",
469 	rk_spi_methods,
470 	sizeof(struct rk_spi_softc),
471 };
472 
473 DRIVER_MODULE(rk_spi, simplebus, rk_spi_driver, 0, 0);
474 DRIVER_MODULE(ofw_spibus, rk_spi, ofw_spibus_driver, 0, 0);
475 MODULE_DEPEND(rk_spi, ofw_spibus, 1, 1, 1);
476 OFWBUS_PNP_INFO(compat_data);
477