xref: /freebsd/sys/arm/mv/mv_spi.c (revision ce6a89e27cd190313be39bb479880aeda4778436)
1 /*-
2  * Copyright (c) 2017-2018, Rubicon Communications, LLC (Netgate)
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <sys/rman.h>
39 
40 #include <machine/bus.h>
41 #include <machine/resource.h>
42 #include <machine/intr.h>
43 
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46 #include <dev/spibus/spi.h>
47 #include <dev/spibus/spibusvar.h>
48 
49 #include <arm/mv/mvvar.h>
50 
51 #include "spibus_if.h"
52 
53 struct mv_spi_softc {
54 	device_t		sc_dev;
55 	struct mtx		sc_mtx;
56 	struct resource		*sc_mem_res;
57 	struct resource		*sc_irq_res;
58 	struct spi_command	*sc_cmd;
59 	bus_space_tag_t		sc_bst;
60 	bus_space_handle_t	sc_bsh;
61 	uint32_t		sc_len;
62 	uint32_t		sc_read;
63 	uint32_t		sc_flags;
64 	uint32_t		sc_written;
65 	void			*sc_intrhand;
66 };
67 
68 #define	MV_SPI_BUSY		0x1
69 #define	MV_SPI_WRITE(_sc, _off, _val)		\
70     bus_space_write_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off), (_val))
71 #define	MV_SPI_READ(_sc, _off)			\
72     bus_space_read_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off))
73 #define	MV_SPI_LOCK(_sc)	mtx_lock(&(_sc)->sc_mtx)
74 #define	MV_SPI_UNLOCK(_sc)	mtx_unlock(&(_sc)->sc_mtx)
75 
76 #define	MV_SPI_CONTROL		0
77 #define	MV_SPI_CTRL_CS_MASK		7
78 #define	MV_SPI_CTRL_CS_SHIFT		2
79 #define	MV_SPI_CTRL_SMEMREADY		(1 << 1)
80 #define	MV_SPI_CTRL_CS_ACTIVE		(1 << 0)
81 #define	MV_SPI_CONF		0x4
82 #define	MV_SPI_CONF_MODE_SHIFT		12
83 #define	MV_SPI_CONF_MODE_MASK		(3 << MV_SPI_CONF_MODE_SHIFT)
84 #define	MV_SPI_CONF_BYTELEN		(1 << 5)
85 #define	MV_SPI_CONF_CLOCK_SPR_MASK	0xf
86 #define	MV_SPI_CONF_CLOCK_SPPR_MASK	1
87 #define	MV_SPI_CONF_CLOCK_SPPR_SHIFT	4
88 #define	MV_SPI_CONF_CLOCK_SPPRHI_MASK	3
89 #define	MV_SPI_CONF_CLOCK_SPPRHI_SHIFT	6
90 #define	MV_SPI_CONF_CLOCK_MASK						\
91     ((MV_SPI_CONF_CLOCK_SPPRHI_MASK << MV_SPI_CONF_CLOCK_SPPRHI_SHIFT) | \
92     (MV_SPI_CONF_CLOCK_SPPR_MASK << MV_SPI_CONF_CLOCK_SPPR_SHIFT) |	\
93     MV_SPI_CONF_CLOCK_SPR_MASK)
94 #define	MV_SPI_DATAOUT		0x8
95 #define	MV_SPI_DATAIN		0xc
96 #define	MV_SPI_INTR_STAT	0x10
97 #define	MV_SPI_INTR_MASK	0x14
98 #define	MV_SPI_INTR_SMEMREADY		(1 << 0)
99 
100 static struct ofw_compat_data compat_data[] = {
101         {"marvell,armada-380-spi",	1},
102         {NULL,                          0}
103 };
104 
105 static void mv_spi_intr(void *);
106 
107 static int
108 mv_spi_probe(device_t dev)
109 {
110 
111 	if (!ofw_bus_status_okay(dev))
112 		return (ENXIO);
113 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
114 		return (ENXIO);
115 
116 	device_set_desc(dev, "Marvell SPI controller");
117 
118 	return (BUS_PROBE_DEFAULT);
119 }
120 
121 static int
122 mv_spi_attach(device_t dev)
123 {
124 	struct mv_spi_softc *sc;
125 	int rid;
126 	uint32_t reg;
127 
128 	sc = device_get_softc(dev);
129 	sc->sc_dev = dev;
130 
131 	rid = 0;
132 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
133 	    RF_ACTIVE);
134 	if (!sc->sc_mem_res) {
135 		device_printf(dev, "cannot allocate memory window\n");
136 		return (ENXIO);
137 	}
138 
139 	sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
140 	sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
141 
142 	rid = 0;
143 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
144 	    RF_ACTIVE);
145 	if (!sc->sc_irq_res) {
146 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
147 		device_printf(dev, "cannot allocate interrupt\n");
148 		return (ENXIO);
149 	}
150 
151 	/* Deactivate the bus - just in case... */
152 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
153 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg & ~MV_SPI_CTRL_CS_ACTIVE);
154 
155 	/* Disable the two bytes FIFO. */
156 	reg = MV_SPI_READ(sc, MV_SPI_CONF);
157 	MV_SPI_WRITE(sc, MV_SPI_CONF, reg & ~MV_SPI_CONF_BYTELEN);
158 
159 	/* Clear and disable interrupts. */
160 	MV_SPI_WRITE(sc, MV_SPI_INTR_MASK, 0);
161 	MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
162 
163 	/* Hook up our interrupt handler. */
164 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
165 	    NULL, mv_spi_intr, sc, &sc->sc_intrhand)) {
166 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
167 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
168 		device_printf(dev, "cannot setup the interrupt handler\n");
169 		return (ENXIO);
170 	}
171 
172 	mtx_init(&sc->sc_mtx, "mv_spi", NULL, MTX_DEF);
173 
174 	device_add_child(dev, "spibus", -1);
175 
176 	/* Probe and attach the spibus when interrupts are available. */
177 	return (bus_delayed_attach_children(dev));
178 }
179 
180 static int
181 mv_spi_detach(device_t dev)
182 {
183 	struct mv_spi_softc *sc;
184 
185 	bus_generic_detach(dev);
186 
187 	sc = device_get_softc(dev);
188 	mtx_destroy(&sc->sc_mtx);
189 	if (sc->sc_intrhand)
190 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
191 	if (sc->sc_irq_res)
192 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
193 	if (sc->sc_mem_res)
194 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
195 
196 	return (0);
197 }
198 
199 static __inline void
200 mv_spi_rx_byte(struct mv_spi_softc *sc)
201 {
202 	struct spi_command *cmd;
203 	uint32_t read;
204 	uint8_t *p;
205 
206 	cmd = sc->sc_cmd;
207 	p = (uint8_t *)cmd->rx_cmd;
208 	read = sc->sc_read++;
209 	if (read >= cmd->rx_cmd_sz) {
210 		p = (uint8_t *)cmd->rx_data;
211 		read -= cmd->rx_cmd_sz;
212 	}
213 	p[read] = MV_SPI_READ(sc, MV_SPI_DATAIN) & 0xff;
214 }
215 
216 static __inline void
217 mv_spi_tx_byte(struct mv_spi_softc *sc)
218 {
219 	struct spi_command *cmd;
220 	uint32_t written;
221 	uint8_t *p;
222 
223 	cmd = sc->sc_cmd;
224 	p = (uint8_t *)cmd->tx_cmd;
225 	written = sc->sc_written++;
226 	if (written >= cmd->tx_cmd_sz) {
227 		p = (uint8_t *)cmd->tx_data;
228 		written -= cmd->tx_cmd_sz;
229 	}
230 	MV_SPI_WRITE(sc, MV_SPI_DATAOUT, p[written]);
231 }
232 
233 static void
234 mv_spi_intr(void *arg)
235 {
236 	struct mv_spi_softc *sc;
237 
238 	sc = (struct mv_spi_softc *)arg;
239 	MV_SPI_LOCK(sc);
240 
241 	/* Filter stray interrupts. */
242 	if ((sc->sc_flags & MV_SPI_BUSY) == 0) {
243 		MV_SPI_UNLOCK(sc);
244 		return;
245 	}
246 
247 	/* RX */
248 	mv_spi_rx_byte(sc);
249 
250 	/* TX */
251 	mv_spi_tx_byte(sc);
252 
253 	/* Check for end of transfer. */
254 	if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len)
255 		wakeup(sc->sc_dev);
256 
257 	MV_SPI_UNLOCK(sc);
258 }
259 
260 static int
261 mv_spi_psc_calc(uint32_t clock, uint32_t *spr, uint32_t *sppr)
262 {
263 	uint32_t divider, tclk;
264 
265 	tclk = get_tclk_armada38x();
266 	for (*spr = 2; *spr <= 15; (*spr)++) {
267 		for (*sppr = 0; *sppr <= 7; (*sppr)++) {
268 			divider = *spr * (1 << *sppr);
269 			if (tclk / divider <= clock)
270 				return (0);
271 		}
272 	}
273 
274 	return (EINVAL);
275 }
276 
277 static int
278 mv_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
279 {
280 	struct mv_spi_softc *sc;
281 	uint32_t clock, cs, mode, reg, spr, sppr;
282 	int resid, timeout;
283 
284 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
285 	    ("TX/RX command sizes should be equal"));
286 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
287 	    ("TX/RX data sizes should be equal"));
288 
289 	/* Get the proper chip select, mode and clock for this transfer. */
290 	spibus_get_cs(child, &cs);
291 	cs &= ~SPIBUS_CS_HIGH;
292 	spibus_get_mode(child, &mode);
293 	if (mode > 3) {
294 		device_printf(dev,
295 		    "Invalid mode %u requested by %s\n", mode,
296 		    device_get_nameunit(child));
297 		return (EINVAL);
298 	}
299 	spibus_get_clock(child, &clock);
300 	if (clock == 0 || mv_spi_psc_calc(clock, &spr, &sppr) != 0) {
301 		device_printf(dev,
302 		    "Invalid clock %uHz requested by %s\n", clock,
303 		    device_get_nameunit(child));
304 		return (EINVAL);
305 	}
306 
307 	sc = device_get_softc(dev);
308 	MV_SPI_LOCK(sc);
309 
310 	/* Wait until the controller is free. */
311 	while (sc->sc_flags & MV_SPI_BUSY)
312 		mtx_sleep(dev, &sc->sc_mtx, 0, "mv_spi", 0);
313 
314 	/* Now we have control over SPI controller. */
315 	sc->sc_flags = MV_SPI_BUSY;
316 
317 	/* Save a pointer to the SPI command. */
318 	sc->sc_cmd = cmd;
319 	sc->sc_read = 0;
320 	sc->sc_written = 0;
321 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
322 
323 	/* Set SPI Mode and Clock. */
324 	reg = MV_SPI_READ(sc, MV_SPI_CONF);
325 	reg &= ~(MV_SPI_CONF_MODE_MASK | MV_SPI_CONF_CLOCK_MASK);
326 	reg |= mode << MV_SPI_CONF_MODE_SHIFT;
327 	reg |= spr & MV_SPI_CONF_CLOCK_SPR_MASK;
328 	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPR_MASK) <<
329 	    MV_SPI_CONF_CLOCK_SPPR_SHIFT;
330 	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPRHI_MASK) <<
331 	    MV_SPI_CONF_CLOCK_SPPRHI_SHIFT;
332 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
333 
334 	/* Set CS number and assert CS. */
335 	reg = (cs & MV_SPI_CTRL_CS_MASK) << MV_SPI_CTRL_CS_SHIFT;
336 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
337 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
338 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg | MV_SPI_CTRL_CS_ACTIVE);
339 
340 	while ((resid = sc->sc_len - sc->sc_written) > 0) {
341 
342 		MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
343 
344 		/*
345 		 * Write to start the transmission and read the byte
346 		 * back when ready.
347 		 */
348 		mv_spi_tx_byte(sc);
349 		timeout = 1000;
350 		while (--timeout > 0) {
351 			reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
352 			if (reg & MV_SPI_CTRL_SMEMREADY)
353 				break;
354 			DELAY(1);
355 		}
356 		if (timeout == 0)
357 			break;
358 		mv_spi_rx_byte(sc);
359 	}
360 
361 	/* Stop the controller. */
362 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
363 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg & ~MV_SPI_CTRL_CS_ACTIVE);
364 	MV_SPI_WRITE(sc, MV_SPI_INTR_MASK, 0);
365 	MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
366 
367 	/* Release the controller and wakeup the next thread waiting for it. */
368 	sc->sc_flags = 0;
369 	wakeup_one(dev);
370 	MV_SPI_UNLOCK(sc);
371 
372 	/*
373 	 * Check for transfer timeout.  The SPI controller doesn't
374 	 * return errors.
375 	 */
376 	return ((timeout == 0) ? EIO : 0);
377 }
378 
379 static phandle_t
380 mv_spi_get_node(device_t bus, device_t dev)
381 {
382 
383 	return (ofw_bus_get_node(bus));
384 }
385 
386 static device_method_t mv_spi_methods[] = {
387 	/* Device interface */
388 	DEVMETHOD(device_probe,		mv_spi_probe),
389 	DEVMETHOD(device_attach,	mv_spi_attach),
390 	DEVMETHOD(device_detach,	mv_spi_detach),
391 
392 	/* SPI interface */
393 	DEVMETHOD(spibus_transfer,	mv_spi_transfer),
394 
395 	/* ofw_bus interface */
396 	DEVMETHOD(ofw_bus_get_node,	mv_spi_get_node),
397 
398 	DEVMETHOD_END
399 };
400 
401 static devclass_t mv_spi_devclass;
402 
403 static driver_t mv_spi_driver = {
404 	"spi",
405 	mv_spi_methods,
406 	sizeof(struct mv_spi_softc),
407 };
408 
409 DRIVER_MODULE(mv_spi, simplebus, mv_spi_driver, mv_spi_devclass, 0, 0);
410