xref: /freebsd/sys/arm/mv/mv_spi.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/bus.h>
31 
32 #include <sys/kernel.h>
33 #include <sys/lock.h>
34 #include <sys/module.h>
35 #include <sys/mutex.h>
36 #include <sys/rman.h>
37 
38 #include <machine/bus.h>
39 #include <machine/resource.h>
40 #include <machine/intr.h>
41 
42 #include <dev/ofw/ofw_bus.h>
43 #include <dev/ofw/ofw_bus_subr.h>
44 #include <dev/spibus/spi.h>
45 #include <dev/spibus/spibusvar.h>
46 
47 #include <arm/mv/mvvar.h>
48 
49 #include "spibus_if.h"
50 
51 struct mv_spi_softc {
52 	device_t		sc_dev;
53 	struct mtx		sc_mtx;
54 	struct resource		*sc_mem_res;
55 	struct resource		*sc_irq_res;
56 	struct spi_command	*sc_cmd;
57 	bus_space_tag_t		sc_bst;
58 	bus_space_handle_t	sc_bsh;
59 	uint32_t		sc_len;
60 	uint32_t		sc_read;
61 	uint32_t		sc_flags;
62 	uint32_t		sc_written;
63 	void			*sc_intrhand;
64 };
65 
66 #define	MV_SPI_BUSY		0x1
67 #define	MV_SPI_WRITE(_sc, _off, _val)		\
68     bus_space_write_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off), (_val))
69 #define	MV_SPI_READ(_sc, _off)			\
70     bus_space_read_4((_sc)->sc_bst, (_sc)->sc_bsh, (_off))
71 #define	MV_SPI_LOCK(_sc)	mtx_lock(&(_sc)->sc_mtx)
72 #define	MV_SPI_UNLOCK(_sc)	mtx_unlock(&(_sc)->sc_mtx)
73 
74 #define	MV_SPI_CONTROL		0
75 #define	MV_SPI_CTRL_CS_MASK		7
76 #define	MV_SPI_CTRL_CS_SHIFT		2
77 #define	MV_SPI_CTRL_SMEMREADY		(1 << 1)
78 #define	MV_SPI_CTRL_CS_ACTIVE		(1 << 0)
79 #define	MV_SPI_CONF		0x4
80 #define	MV_SPI_CONF_MODE_SHIFT		12
81 #define	MV_SPI_CONF_MODE_MASK		(3 << MV_SPI_CONF_MODE_SHIFT)
82 #define	MV_SPI_CONF_BYTELEN		(1 << 5)
83 #define	MV_SPI_CONF_CLOCK_SPR_MASK	0xf
84 #define	MV_SPI_CONF_CLOCK_SPPR_MASK	1
85 #define	MV_SPI_CONF_CLOCK_SPPR_SHIFT	4
86 #define	MV_SPI_CONF_CLOCK_SPPRHI_MASK	3
87 #define	MV_SPI_CONF_CLOCK_SPPRHI_SHIFT	6
88 #define	MV_SPI_CONF_CLOCK_MASK						\
89     ((MV_SPI_CONF_CLOCK_SPPRHI_MASK << MV_SPI_CONF_CLOCK_SPPRHI_SHIFT) | \
90     (MV_SPI_CONF_CLOCK_SPPR_MASK << MV_SPI_CONF_CLOCK_SPPR_SHIFT) |	\
91     MV_SPI_CONF_CLOCK_SPR_MASK)
92 #define	MV_SPI_DATAOUT		0x8
93 #define	MV_SPI_DATAIN		0xc
94 #define	MV_SPI_INTR_STAT	0x10
95 #define	MV_SPI_INTR_MASK	0x14
96 #define	MV_SPI_INTR_SMEMREADY		(1 << 0)
97 
98 static struct ofw_compat_data compat_data[] = {
99         {"marvell,armada-380-spi",	1},
100         {NULL,                          0}
101 };
102 
103 static void mv_spi_intr(void *);
104 
105 static int
106 mv_spi_probe(device_t dev)
107 {
108 
109 	if (!ofw_bus_status_okay(dev))
110 		return (ENXIO);
111 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
112 		return (ENXIO);
113 
114 	device_set_desc(dev, "Marvell SPI controller");
115 
116 	return (BUS_PROBE_DEFAULT);
117 }
118 
119 static int
120 mv_spi_attach(device_t dev)
121 {
122 	struct mv_spi_softc *sc;
123 	int rid;
124 	uint32_t reg;
125 
126 	sc = device_get_softc(dev);
127 	sc->sc_dev = dev;
128 
129 	rid = 0;
130 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
131 	    RF_ACTIVE);
132 	if (!sc->sc_mem_res) {
133 		device_printf(dev, "cannot allocate memory window\n");
134 		return (ENXIO);
135 	}
136 
137 	sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
138 	sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
139 
140 	rid = 0;
141 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
142 	    RF_ACTIVE);
143 	if (!sc->sc_irq_res) {
144 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
145 		device_printf(dev, "cannot allocate interrupt\n");
146 		return (ENXIO);
147 	}
148 
149 	/* Deactivate the bus - just in case... */
150 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
151 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg & ~MV_SPI_CTRL_CS_ACTIVE);
152 
153 	/* Disable the two bytes FIFO. */
154 	reg = MV_SPI_READ(sc, MV_SPI_CONF);
155 	MV_SPI_WRITE(sc, MV_SPI_CONF, reg & ~MV_SPI_CONF_BYTELEN);
156 
157 	/* Clear and disable interrupts. */
158 	MV_SPI_WRITE(sc, MV_SPI_INTR_MASK, 0);
159 	MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
160 
161 	/* Hook up our interrupt handler. */
162 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
163 	    NULL, mv_spi_intr, sc, &sc->sc_intrhand)) {
164 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
165 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
166 		device_printf(dev, "cannot setup the interrupt handler\n");
167 		return (ENXIO);
168 	}
169 
170 	mtx_init(&sc->sc_mtx, "mv_spi", NULL, MTX_DEF);
171 
172 	device_add_child(dev, "spibus", -1);
173 
174 	/* Probe and attach the spibus when interrupts are available. */
175 	return (bus_delayed_attach_children(dev));
176 }
177 
178 static int
179 mv_spi_detach(device_t dev)
180 {
181 	struct mv_spi_softc *sc;
182 
183 	bus_generic_detach(dev);
184 
185 	sc = device_get_softc(dev);
186 	mtx_destroy(&sc->sc_mtx);
187 	if (sc->sc_intrhand)
188 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
189 	if (sc->sc_irq_res)
190 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
191 	if (sc->sc_mem_res)
192 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
193 
194 	return (0);
195 }
196 
197 static __inline void
198 mv_spi_rx_byte(struct mv_spi_softc *sc)
199 {
200 	struct spi_command *cmd;
201 	uint32_t read;
202 	uint8_t *p;
203 
204 	cmd = sc->sc_cmd;
205 	p = (uint8_t *)cmd->rx_cmd;
206 	read = sc->sc_read++;
207 	if (read >= cmd->rx_cmd_sz) {
208 		p = (uint8_t *)cmd->rx_data;
209 		read -= cmd->rx_cmd_sz;
210 	}
211 	p[read] = MV_SPI_READ(sc, MV_SPI_DATAIN) & 0xff;
212 }
213 
214 static __inline void
215 mv_spi_tx_byte(struct mv_spi_softc *sc)
216 {
217 	struct spi_command *cmd;
218 	uint32_t written;
219 	uint8_t *p;
220 
221 	cmd = sc->sc_cmd;
222 	p = (uint8_t *)cmd->tx_cmd;
223 	written = sc->sc_written++;
224 	if (written >= cmd->tx_cmd_sz) {
225 		p = (uint8_t *)cmd->tx_data;
226 		written -= cmd->tx_cmd_sz;
227 	}
228 	MV_SPI_WRITE(sc, MV_SPI_DATAOUT, p[written]);
229 }
230 
231 static void
232 mv_spi_intr(void *arg)
233 {
234 	struct mv_spi_softc *sc;
235 
236 	sc = (struct mv_spi_softc *)arg;
237 	MV_SPI_LOCK(sc);
238 
239 	/* Filter stray interrupts. */
240 	if ((sc->sc_flags & MV_SPI_BUSY) == 0) {
241 		MV_SPI_UNLOCK(sc);
242 		return;
243 	}
244 
245 	/* RX */
246 	mv_spi_rx_byte(sc);
247 
248 	/* TX */
249 	mv_spi_tx_byte(sc);
250 
251 	/* Check for end of transfer. */
252 	if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len)
253 		wakeup(sc->sc_dev);
254 
255 	MV_SPI_UNLOCK(sc);
256 }
257 
258 static int
259 mv_spi_psc_calc(uint32_t clock, uint32_t *spr, uint32_t *sppr)
260 {
261 	uint32_t divider, tclk;
262 
263 	tclk = get_tclk_armada38x();
264 	for (*spr = 2; *spr <= 15; (*spr)++) {
265 		for (*sppr = 0; *sppr <= 7; (*sppr)++) {
266 			divider = *spr * (1 << *sppr);
267 			if (tclk / divider <= clock)
268 				return (0);
269 		}
270 	}
271 
272 	return (EINVAL);
273 }
274 
275 static int
276 mv_spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
277 {
278 	struct mv_spi_softc *sc;
279 	uint32_t clock, cs, mode, reg, spr, sppr;
280 	int resid, timeout;
281 
282 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
283 	    ("TX/RX command sizes should be equal"));
284 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
285 	    ("TX/RX data sizes should be equal"));
286 
287 	/* Get the proper chip select, mode and clock for this transfer. */
288 	spibus_get_cs(child, &cs);
289 	cs &= ~SPIBUS_CS_HIGH;
290 	spibus_get_mode(child, &mode);
291 	if (mode > 3) {
292 		device_printf(dev,
293 		    "Invalid mode %u requested by %s\n", mode,
294 		    device_get_nameunit(child));
295 		return (EINVAL);
296 	}
297 	spibus_get_clock(child, &clock);
298 	if (clock == 0 || mv_spi_psc_calc(clock, &spr, &sppr) != 0) {
299 		device_printf(dev,
300 		    "Invalid clock %uHz requested by %s\n", clock,
301 		    device_get_nameunit(child));
302 		return (EINVAL);
303 	}
304 
305 	sc = device_get_softc(dev);
306 	MV_SPI_LOCK(sc);
307 
308 	/* Wait until the controller is free. */
309 	while (sc->sc_flags & MV_SPI_BUSY)
310 		mtx_sleep(dev, &sc->sc_mtx, 0, "mv_spi", 0);
311 
312 	/* Now we have control over SPI controller. */
313 	sc->sc_flags = MV_SPI_BUSY;
314 
315 	/* Save a pointer to the SPI command. */
316 	sc->sc_cmd = cmd;
317 	sc->sc_read = 0;
318 	sc->sc_written = 0;
319 	sc->sc_len = cmd->tx_cmd_sz + cmd->tx_data_sz;
320 
321 	/* Set SPI Mode and Clock. */
322 	reg = MV_SPI_READ(sc, MV_SPI_CONF);
323 	reg &= ~(MV_SPI_CONF_MODE_MASK | MV_SPI_CONF_CLOCK_MASK);
324 	reg |= mode << MV_SPI_CONF_MODE_SHIFT;
325 	reg |= spr & MV_SPI_CONF_CLOCK_SPR_MASK;
326 	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPR_MASK) <<
327 	    MV_SPI_CONF_CLOCK_SPPR_SHIFT;
328 	reg |= (sppr & MV_SPI_CONF_CLOCK_SPPRHI_MASK) <<
329 	    MV_SPI_CONF_CLOCK_SPPRHI_SHIFT;
330 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
331 
332 	/* Set CS number and assert CS. */
333 	reg = (cs & MV_SPI_CTRL_CS_MASK) << MV_SPI_CTRL_CS_SHIFT;
334 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg);
335 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
336 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg | MV_SPI_CTRL_CS_ACTIVE);
337 
338 	while ((resid = sc->sc_len - sc->sc_written) > 0) {
339 		MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
340 
341 		/*
342 		 * Write to start the transmission and read the byte
343 		 * back when ready.
344 		 */
345 		mv_spi_tx_byte(sc);
346 		timeout = 1000;
347 		while (--timeout > 0) {
348 			reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
349 			if (reg & MV_SPI_CTRL_SMEMREADY)
350 				break;
351 			DELAY(1);
352 		}
353 		if (timeout == 0)
354 			break;
355 		mv_spi_rx_byte(sc);
356 	}
357 
358 	/* Stop the controller. */
359 	reg = MV_SPI_READ(sc, MV_SPI_CONTROL);
360 	MV_SPI_WRITE(sc, MV_SPI_CONTROL, reg & ~MV_SPI_CTRL_CS_ACTIVE);
361 	MV_SPI_WRITE(sc, MV_SPI_INTR_MASK, 0);
362 	MV_SPI_WRITE(sc, MV_SPI_INTR_STAT, 0);
363 
364 	/* Release the controller and wakeup the next thread waiting for it. */
365 	sc->sc_flags = 0;
366 	wakeup_one(dev);
367 	MV_SPI_UNLOCK(sc);
368 
369 	/*
370 	 * Check for transfer timeout.  The SPI controller doesn't
371 	 * return errors.
372 	 */
373 	return ((timeout == 0) ? EIO : 0);
374 }
375 
376 static phandle_t
377 mv_spi_get_node(device_t bus, device_t dev)
378 {
379 
380 	return (ofw_bus_get_node(bus));
381 }
382 
383 static device_method_t mv_spi_methods[] = {
384 	/* Device interface */
385 	DEVMETHOD(device_probe,		mv_spi_probe),
386 	DEVMETHOD(device_attach,	mv_spi_attach),
387 	DEVMETHOD(device_detach,	mv_spi_detach),
388 
389 	/* SPI interface */
390 	DEVMETHOD(spibus_transfer,	mv_spi_transfer),
391 
392 	/* ofw_bus interface */
393 	DEVMETHOD(ofw_bus_get_node,	mv_spi_get_node),
394 
395 	DEVMETHOD_END
396 };
397 
398 static driver_t mv_spi_driver = {
399 	"spi",
400 	mv_spi_methods,
401 	sizeof(struct mv_spi_softc),
402 };
403 
404 DRIVER_MODULE(mv_spi, simplebus, mv_spi_driver, 0, 0);
405