xref: /freebsd/sys/arm/mv/mv_spi.c (revision 87b759f0fa1f7554d50ce640c40138512bbded44)
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/param.h>
28 #include <sys/systm.h>
29 #include <sys/bus.h>
30 
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 
37 #include <machine/bus.h>
38 #include <machine/resource.h>
39 #include <machine/intr.h>
40 
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 #include <dev/spibus/spi.h>
44 #include <dev/spibus/spibusvar.h>
45 
46 #include <arm/mv/mvvar.h>
47 
48 #include "spibus_if.h"
49 
50 struct mv_spi_softc {
51 	device_t		sc_dev;
52 	struct mtx		sc_mtx;
53 	struct resource		*sc_mem_res;
54 	struct resource		*sc_irq_res;
55 	struct spi_command	*sc_cmd;
56 	bus_space_tag_t		sc_bst;
57 	bus_space_handle_t	sc_bsh;
58 	uint32_t		sc_len;
59 	uint32_t		sc_read;
60 	uint32_t		sc_flags;
61 	uint32_t		sc_written;
62 	void			*sc_intrhand;
63 };
64 
65 #define	MV_SPI_BUSY		0x1
66 #define	MV_SPI_WRITE(_sc, _off, _val)		\
67     bus_space_write_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off), (_val))
68 #define	MV_SPI_READ(_sc, _off)			\
69     bus_space_read_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off))
70 #define	MV_SPI_LOCK(_sc)	mtx_lock(&(_sc)->sc_mtx)
71 #define	MV_SPI_UNLOCK(_sc)	mtx_unlock(&(_sc)->sc_mtx)
72 
73 #define	MV_SPI_CONTROL		0
74 #define	MV_SPI_CTRL_CS_MASK		7
75 #define	MV_SPI_CTRL_CS_SHIFT		2
76 #define	MV_SPI_CTRL_SMEMREADY		(1 << 1)
77 #define	MV_SPI_CTRL_CS_ACTIVE		(1 << 0)
78 #define	MV_SPI_CONF		0x4
79 #define	MV_SPI_CONF_MODE_SHIFT		12
80 #define	MV_SPI_CONF_MODE_MASK		(3 << MV_SPI_CONF_MODE_SHIFT)
81 #define	MV_SPI_CONF_BYTELEN		(1 << 5)
82 #define	MV_SPI_CONF_CLOCK_SPR_MASK	0xf
83 #define	MV_SPI_CONF_CLOCK_SPPR_MASK	1
84 #define	MV_SPI_CONF_CLOCK_SPPR_SHIFT	4
85 #define	MV_SPI_CONF_CLOCK_SPPRHI_MASK	3
86 #define	MV_SPI_CONF_CLOCK_SPPRHI_SHIFT	6
87 #define	MV_SPI_CONF_CLOCK_MASK						\
88     ((MV_SPI_CONF_CLOCK_SPPRHI_MASK << MV_SPI_CONF_CLOCK_SPPRHI_SHIFT) | \
89     (MV_SPI_CONF_CLOCK_SPPR_MASK << MV_SPI_CONF_CLOCK_SPPR_SHIFT) |	\
90     MV_SPI_CONF_CLOCK_SPR_MASK)
91 #define	MV_SPI_DATAOUT		0x8
92 #define	MV_SPI_DATAIN		0xc
93 #define	MV_SPI_INTR_STAT	0x10
94 #define	MV_SPI_INTR_MASK	0x14
95 #define	MV_SPI_INTR_SMEMREADY		(1 << 0)
96 
97 static struct ofw_compat_data compat_data[] = {
98         {"marvell,armada-380-spi",	1},
99         {NULL,                          0}
100 };
101 
102 static void mv_spi_intr(void *);
103 
104 static int
105 mv_spi_probe(device_t dev)
106 {
107 
108 	if (!ofw_bus_status_okay(dev))
109 		return (ENXIO);
110 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
111 		return (ENXIO);
112 
113 	device_set_desc(dev, "Marvell SPI controller");
114 
115 	return (BUS_PROBE_DEFAULT);
116 }
117 
118 static int
119 mv_spi_attach(device_t dev)
120 {
121 	struct mv_spi_softc *sc;
122 	int rid;
123 	uint32_t reg;
124 
125 	sc = device_get_softc(dev);
126 	sc->sc_dev = dev;
127 
128 	rid = 0;
129 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
130 	    RF_ACTIVE);
131 	if (!sc->sc_mem_res) {
132 		device_printf(dev, "cannot allocate memory window\n");
133 		return (ENXIO);
134 	}
135 
136 	sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
137 	sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
138 
139 	rid = 0;
140 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
141 	    RF_ACTIVE);
142 	if (!sc->sc_irq_res) {
143 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
144 		device_printf(dev, "cannot allocate interrupt\n");
145 		return (ENXIO);
146 	}
147 
148 	/* Deactivate the bus - just in case... */
149 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
150 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg & ~MV_SPI_CTRL_CS_ACTIVE);
151 
152 	/* Disable the two bytes FIFO. */
153 	reg = MV_SPI_READ(sc, MV_SPI_CONF);
154 	MV_SPI_WRITE(sc, MV_SPI_CONF, reg & ~MV_SPI_CONF_BYTELEN);
155 
156 	/* Clear and disable interrupts. */
157 	MV_SPI_WRITE(sc, MV_SPI_INTR_MASK, 0);
158 	MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
159 
160 	/* Hook up our interrupt handler. */
161 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
162 	    NULL, mv_spi_intr, sc, &sc->sc_intrhand)) {
163 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
164 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
165 		device_printf(dev, "cannot setup the interrupt handler\n");
166 		return (ENXIO);
167 	}
168 
169 	mtx_init(&sc->sc_mtx, "mv_spi", NULL, MTX_DEF);
170 
171 	device_add_child(dev, "spibus", DEVICE_UNIT_ANY);
172 
173 	/* Probe and attach the spibus when interrupts are available. */
174 	return (bus_delayed_attach_children(dev));
175 }
176 
177 static int
178 mv_spi_detach(device_t dev)
179 {
180 	struct mv_spi_softc *sc;
181 
182 	bus_generic_detach(dev);
183 
184 	sc = device_get_softc(dev);
185 	mtx_destroy(&sc->sc_mtx);
186 	if (sc->sc_intrhand)
187 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
188 	if (sc->sc_irq_res)
189 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
190 	if (sc->sc_mem_res)
191 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
192 
193 	return (0);
194 }
195 
196 static __inline void
197 mv_spi_rx_byte(struct mv_spi_softc *sc)
198 {
199 	struct spi_command *cmd;
200 	uint32_t read;
201 	uint8_t *p;
202 
203 	cmd = sc->sc_cmd;
204 	p = (uint8_t *)cmd->rx_cmd;
205 	read = sc->sc_read++;
206 	if (read >= cmd->rx_cmd_sz) {
207 		p = (uint8_t *)cmd->rx_data;
208 		read -= cmd->rx_cmd_sz;
209 	}
210 	p[read] = MV_SPI_READ(sc, MV_SPI_DATAIN) & 0xff;
211 }
212 
213 static __inline void
214 mv_spi_tx_byte(struct mv_spi_softc *sc)
215 {
216 	struct spi_command *cmd;
217 	uint32_t written;
218 	uint8_t *p;
219 
220 	cmd = sc->sc_cmd;
221 	p = (uint8_t *)cmd->tx_cmd;
222 	written = sc->sc_written++;
223 	if (written >= cmd->tx_cmd_sz) {
224 		p = (uint8_t *)cmd->tx_data;
225 		written -= cmd->tx_cmd_sz;
226 	}
227 	MV_SPI_WRITE(sc, MV_SPI_DATAOUT, p[written]);
228 }
229 
230 static void
231 mv_spi_intr(void *arg)
232 {
233 	struct mv_spi_softc *sc;
234 
235 	sc = (struct mv_spi_softc *)arg;
236 	MV_SPI_LOCK(sc);
237 
238 	/* Filter stray interrupts. */
239 	if ((sc->sc_flags & MV_SPI_BUSY) == 0) {
240 		MV_SPI_UNLOCK(sc);
241 		return;
242 	}
243 
244 	/* RX */
245 	mv_spi_rx_byte(sc);
246 
247 	/* TX */
248 	mv_spi_tx_byte(sc);
249 
250 	/* Check for end of transfer. */
251 	if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len)
252 		wakeup(sc->sc_dev);
253 
254 	MV_SPI_UNLOCK(sc);
255 }
256 
257 static int
258 mv_spi_psc_calc(uint32_t clock, uint32_t *spr, uint32_t *sppr)
259 {
260 	uint32_t divider, tclk;
261 
262 	tclk = get_tclk_armada38x();
263 	for (*spr = 2; *spr <= 15; (*spr)++) {
264 		for (*sppr = 0; *sppr <= 7; (*sppr)++) {
265 			divider = *spr * (1 << *sppr);
266 			if (tclk / divider <= clock)
267 				return (0);
268 		}
269 	}
270 
271 	return (EINVAL);
272 }
273 
274 static int
275 mv_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
276 {
277 	struct mv_spi_softc *sc;
278 	uint32_t clock, cs, mode, reg, spr, sppr;
279 	int resid, timeout;
280 
281 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
282 	    ("TX/RX command sizes should be equal"));
283 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
284 	    ("TX/RX data sizes should be equal"));
285 
286 	/* Get the proper chip select, mode and clock for this transfer. */
287 	spibus_get_cs(child, &cs);
288 	cs &= ~SPIBUS_CS_HIGH;
289 	spibus_get_mode(child, &mode);
290 	if (mode > 3) {
291 		device_printf(dev,
292 		    "Invalid mode %u requested by %s\n", mode,
293 		    device_get_nameunit(child));
294 		return (EINVAL);
295 	}
296 	spibus_get_clock(child, &clock);
297 	if (clock == 0 || mv_spi_psc_calc(clock, &spr, &sppr) != 0) {
298 		device_printf(dev,
299 		    "Invalid clock %uHz requested by %s\n", clock,
300 		    device_get_nameunit(child));
301 		return (EINVAL);
302 	}
303 
304 	sc = device_get_softc(dev);
305 	MV_SPI_LOCK(sc);
306 
307 	/* Wait until the controller is free. */
308 	while (sc->sc_flags & MV_SPI_BUSY)
309 		mtx_sleep(dev, &sc->sc_mtx, 0, "mv_spi", 0);
310 
311 	/* Now we have control over SPI controller. */
312 	sc->sc_flags = MV_SPI_BUSY;
313 
314 	/* Save a pointer to the SPI command. */
315 	sc->sc_cmd = cmd;
316 	sc->sc_read = 0;
317 	sc->sc_written = 0;
318 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
319 
320 	/* Set SPI Mode and Clock. */
321 	reg = MV_SPI_READ(sc, MV_SPI_CONF);
322 	reg &= ~(MV_SPI_CONF_MODE_MASK | MV_SPI_CONF_CLOCK_MASK);
323 	reg |= mode << MV_SPI_CONF_MODE_SHIFT;
324 	reg |= spr & MV_SPI_CONF_CLOCK_SPR_MASK;
325 	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPR_MASK) <<
326 	    MV_SPI_CONF_CLOCK_SPPR_SHIFT;
327 	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPRHI_MASK) <<
328 	    MV_SPI_CONF_CLOCK_SPPRHI_SHIFT;
329 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
330 
331 	/* Set CS number and assert CS. */
332 	reg = (cs & MV_SPI_CTRL_CS_MASK) << MV_SPI_CTRL_CS_SHIFT;
333 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
334 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
335 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg | MV_SPI_CTRL_CS_ACTIVE);
336 
337 	while ((resid = sc->sc_len - sc->sc_written) > 0) {
338 		MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
339 
340 		/*
341 		 * Write to start the transmission and read the byte
342 		 * back when ready.
343 		 */
344 		mv_spi_tx_byte(sc);
345 		timeout = 1000;
346 		while (--timeout > 0) {
347 			reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
348 			if (reg & MV_SPI_CTRL_SMEMREADY)
349 				break;
350 			DELAY(1);
351 		}
352 		if (timeout == 0)
353 			break;
354 		mv_spi_rx_byte(sc);
355 	}
356 
357 	/* Stop the controller. */
358 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
359 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg & ~MV_SPI_CTRL_CS_ACTIVE);
360 	MV_SPI_WRITE(sc, MV_SPI_INTR_MASK, 0);
361 	MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
362 
363 	/* Release the controller and wakeup the next thread waiting for it. */
364 	sc->sc_flags = 0;
365 	wakeup_one(dev);
366 	MV_SPI_UNLOCK(sc);
367 
368 	/*
369 	 * Check for transfer timeout.  The SPI controller doesn't
370 	 * return errors.
371 	 */
372 	return ((timeout == 0) ? EIO : 0);
373 }
374 
375 static phandle_t
376 mv_spi_get_node(device_t bus, device_t dev)
377 {
378 
379 	return (ofw_bus_get_node(bus));
380 }
381 
382 static device_method_t mv_spi_methods[] = {
383 	/* Device interface */
384 	DEVMETHOD(device_probe,		mv_spi_probe),
385 	DEVMETHOD(device_attach,	mv_spi_attach),
386 	DEVMETHOD(device_detach,	mv_spi_detach),
387 
388 	/* SPI interface */
389 	DEVMETHOD(spibus_transfer,	mv_spi_transfer),
390 
391 	/* ofw_bus interface */
392 	DEVMETHOD(ofw_bus_get_node,	mv_spi_get_node),
393 
394 	DEVMETHOD_END
395 };
396 
397 static driver_t mv_spi_driver = {
398 	"spi",
399 	mv_spi_methods,
400 	sizeof(struct mv_spi_softc),
401 };
402 
403 DRIVER_MODULE(mv_spi, simplebus, mv_spi_driver, 0, 0);
404