1 /* $NetBSD: gttwsi_core.c,v 1.18 2021/08/07 16:19:11 thorpej Exp $ */
2 /*
3 * Copyright (c) 2008 Eiji Kawauchi.
4 * All rights reserved.
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 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed for the NetBSD Project by
17 * Eiji Kawauchi.
18 * 4. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32 /*
33 * Copyright (c) 2005 Brocade Communcations, inc.
34 * All rights reserved.
35 *
36 * Written by Matt Thomas for Brocade Communcations, Inc.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. The name of Brocade Communications, Inc. may not be used to endorse
47 * or promote products derived from this software without specific prior
48 * written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY BROCADE COMMUNICATIONS, INC. ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL EITHER BROCADE COMMUNICATIONS, INC. BE
54 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
55 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
56 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
57 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
58 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
59 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
60 * OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62 //#define TWSI_DEBUG
63
64 /*
65 * Marvell Two-Wire Serial Interface (aka I2C) master driver
66 */
67
68 #include <sys/cdefs.h>
69 __KERNEL_RCSID(0, "$NetBSD: gttwsi_core.c,v 1.18 2021/08/07 16:19:11 thorpej Exp $");
70 #include "locators.h"
71
72 #include <sys/param.h>
73 #include <sys/bus.h>
74 #include <sys/condvar.h>
75 #include <sys/device.h>
76 #include <sys/errno.h>
77 #include <sys/kernel.h>
78 #include <sys/mutex.h>
79 #include <sys/systm.h>
80
81 #include <dev/i2c/i2cvar.h>
82
83 #include <dev/i2c/gttwsireg.h>
84 #include <dev/i2c/gttwsivar.h>
85
86 static int gttwsi_send_start(void *v, int flags);
87 static int gttwsi_send_stop(void *v, int flags);
88 static int gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags);
89 static int gttwsi_read_byte(void *v, uint8_t *valp, int flags);
90 static int gttwsi_write_byte(void *v, uint8_t val, int flags);
91
92 static int gttwsi_wait(struct gttwsi_softc *, uint32_t, uint32_t,
93 uint32_t, int, const char *);
94
95 uint32_t
gttwsi_read_4(struct gttwsi_softc * sc,uint32_t reg)96 gttwsi_read_4(struct gttwsi_softc *sc, uint32_t reg)
97 {
98 const uint32_t val = bus_space_read_4(sc->sc_bust, sc->sc_bush,
99 sc->sc_regmap[reg]);
100 #ifdef TWSI_DEBUG
101 printf("I2C:R:[%" PRIu32 "]%02" PRIxBUSSIZE ":%02" PRIx32 "\n", reg, sc->sc_regmap[reg], val);
102 #else
103 DELAY(TWSI_READ_DELAY);
104 #endif
105 return val;
106 }
107
108 void
gttwsi_write_4(struct gttwsi_softc * sc,uint32_t reg,uint32_t val)109 gttwsi_write_4(struct gttwsi_softc *sc, uint32_t reg, uint32_t val)
110 {
111
112 bus_space_write_4(sc->sc_bust, sc->sc_bush, sc->sc_regmap[reg], val);
113 #ifdef TWSI_DEBUG
114 printf("I2C:W:[%" PRIu32 "]%02" PRIxBUSSIZE ":%02" PRIx32 "\n", reg, sc->sc_regmap[reg], val);
115 #else
116 DELAY(TWSI_WRITE_DELAY);
117 #endif
118 }
119
120 /* ARGSUSED */
121 void
gttwsi_attach_subr(device_t self,bus_space_tag_t iot,bus_space_handle_t ioh,const bus_size_t * regmap)122 gttwsi_attach_subr(device_t self, bus_space_tag_t iot, bus_space_handle_t ioh,
123 const bus_size_t *regmap)
124 {
125 struct gttwsi_softc * const sc = device_private(self);
126 prop_dictionary_t cfg = device_properties(self);
127
128 aprint_naive("\n");
129 aprint_normal(": Marvell TWSI controller\n");
130
131 sc->sc_dev = self;
132 sc->sc_bust = iot;
133 sc->sc_bush = ioh;
134 sc->sc_regmap = regmap;
135
136 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_BIO);
137 cv_init(&sc->sc_cv, device_xname(self));
138
139 prop_dictionary_get_bool(cfg, "iflg-rwc", &sc->sc_iflg_rwc);
140
141 sc->sc_started = false;
142 iic_tag_init(&sc->sc_i2c);
143 sc->sc_i2c.ic_cookie = sc;
144 sc->sc_i2c.ic_send_start = gttwsi_send_start;
145 sc->sc_i2c.ic_send_stop = gttwsi_send_stop;
146 sc->sc_i2c.ic_initiate_xfer = gttwsi_initiate_xfer;
147 sc->sc_i2c.ic_read_byte = gttwsi_read_byte;
148 sc->sc_i2c.ic_write_byte = gttwsi_write_byte;
149
150 /*
151 * Put the controller into Soft Reset.
152 */
153 /* reset */
154 gttwsi_write_4(sc, TWSI_SOFTRESET, SOFTRESET_VAL);
155 }
156
157 void
gttwsi_config_children(device_t self)158 gttwsi_config_children(device_t self)
159 {
160 struct gttwsi_softc * const sc = device_private(self);
161 struct i2cbus_attach_args iba;
162
163 memset(&iba, 0, sizeof(iba));
164 iba.iba_tag = &sc->sc_i2c;
165
166 config_found(sc->sc_dev, &iba, iicbus_print,
167 CFARGS(.iattr = "i2cbus"));
168 }
169
170 int
gttwsi_intr(void * arg)171 gttwsi_intr(void *arg)
172 {
173 struct gttwsi_softc *sc = arg;
174 uint32_t val;
175
176 mutex_enter(&sc->sc_mtx);
177 val = gttwsi_read_4(sc, TWSI_CONTROL);
178 if (val & CONTROL_IFLG) {
179 gttwsi_write_4(sc, TWSI_CONTROL, val & ~CONTROL_INTEN);
180 cv_broadcast(&sc->sc_cv);
181 mutex_exit(&sc->sc_mtx);
182 return 1; /* handled */
183 }
184 mutex_exit(&sc->sc_mtx);
185 return 0;
186 }
187
188 static int
gttwsi_send_start(void * v,int flags)189 gttwsi_send_start(void *v, int flags)
190 {
191 struct gttwsi_softc *sc = v;
192 int expect;
193
194 if (sc->sc_started)
195 expect = STAT_RSCT;
196 else
197 expect = STAT_SCT;
198 sc->sc_started = true;
199 return gttwsi_wait(sc, CONTROL_START, expect, 0, flags, "send-start");
200 }
201
202 static int
gttwsi_send_stop(void * v,int flags)203 gttwsi_send_stop(void *v, int flags)
204 {
205 struct gttwsi_softc *sc = v;
206 int retry = TWSI_RETRY_COUNT;
207 uint32_t control, status;
208
209 sc->sc_started = false;
210
211 /* Interrupt is not generated for STAT_NRS. */
212 control = CONTROL_STOP | CONTROL_TWSIEN;
213 if (sc->sc_iflg_rwc)
214 control |= CONTROL_IFLG;
215 gttwsi_write_4(sc, TWSI_CONTROL, control);
216 while (retry > 0) {
217 if ((status = gttwsi_read_4(sc, TWSI_STATUS)) == STAT_NRS)
218 return 0;
219 retry--;
220 DELAY(TWSI_STAT_DELAY);
221 }
222
223 aprint_error_dev(sc->sc_dev, "send STOP failed, status=0x%02x\n",
224 status);
225 return EWOULDBLOCK;
226 }
227
228 static int
gttwsi_initiate_xfer(void * v,i2c_addr_t addr,int flags)229 gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags)
230 {
231 struct gttwsi_softc *sc = v;
232 uint32_t data, expect, alt;
233 int error, read;
234
235 error = gttwsi_send_start(v, flags);
236 if (error)
237 return error;
238
239 read = (flags & I2C_F_READ) != 0;
240 if (read) {
241 expect = STAT_ARBT_AR;
242 alt = STAT_ARBT_ANR;
243 } else {
244 expect = STAT_AWBT_AR;
245 alt = STAT_AWBT_ANR;
246 }
247
248 /*
249 * First byte contains whether this xfer is a read or write.
250 */
251 data = read;
252 if (addr > 0x7f) {
253 /*
254 * If this is a 10bit request, the first address byte is
255 * 0b11110<b9><b8><r/w>.
256 */
257 data |= 0xf0 | ((addr & 0x300) >> 7);
258 gttwsi_write_4(sc, TWSI_DATA, data);
259 error = gttwsi_wait(sc, 0, expect, alt, flags, "send-addr-10");
260 if (error)
261 return error;
262 /*
263 * The first address byte has been sent, now to send
264 * the second one.
265 */
266 if (read) {
267 expect = STAT_SARBT_AR;
268 alt = STAT_SARBT_ANR;
269 } else {
270 expect = STAT_SAWBT_AR;
271 alt = STAT_SAWBT_ANR;
272 }
273 data = (uint8_t)addr;
274 } else
275 data |= (addr << 1);
276
277 gttwsi_write_4(sc, TWSI_DATA, data);
278 return gttwsi_wait(sc, 0, expect, alt, flags, "send-addr");
279 }
280
281 static int
gttwsi_read_byte(void * v,uint8_t * valp,int flags)282 gttwsi_read_byte(void *v, uint8_t *valp, int flags)
283 {
284 struct gttwsi_softc *sc = v;
285 int error;
286
287 if (flags & I2C_F_LAST) {
288 error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, 0, flags,
289 "read-last-byte");
290 } else {
291 error = gttwsi_wait(sc, CONTROL_ACK, STAT_MRRD_AT, 0, flags,
292 "read-byte");
293 }
294 if (!error)
295 *valp = gttwsi_read_4(sc, TWSI_DATA);
296 if ((flags & (I2C_F_LAST | I2C_F_STOP)) == (I2C_F_LAST | I2C_F_STOP))
297 error = gttwsi_send_stop(sc, flags);
298 return error;
299 }
300
301 static int
gttwsi_write_byte(void * v,uint8_t val,int flags)302 gttwsi_write_byte(void *v, uint8_t val, int flags)
303 {
304 struct gttwsi_softc *sc = v;
305 int error;
306
307 gttwsi_write_4(sc, TWSI_DATA, val);
308 error = gttwsi_wait(sc, 0, STAT_MTDB_AR, 0, flags, "write-byte");
309 if (flags & I2C_F_STOP)
310 gttwsi_send_stop(sc, flags);
311 return error;
312 }
313
314 static int
gttwsi_wait(struct gttwsi_softc * sc,uint32_t control,uint32_t expect,uint32_t alt,int flags,const char * what)315 gttwsi_wait(struct gttwsi_softc *sc, uint32_t control, uint32_t expect,
316 uint32_t alt, int flags, const char *what)
317 {
318 uint32_t status;
319 int timo, error = 0;
320
321 /*
322 * XXX Interrupt-driven mode seems to be horribly broken,
323 * XXX at least on AllWinner implementations. Force polled
324 * XXX mode for now.
325 */
326 flags |= I2C_F_POLL;
327
328 DELAY(5);
329 if (!(flags & I2C_F_POLL))
330 control |= CONTROL_INTEN;
331 if (sc->sc_iflg_rwc)
332 control |= CONTROL_IFLG;
333 mutex_enter(&sc->sc_mtx);
334 gttwsi_write_4(sc, TWSI_CONTROL, control | CONTROL_TWSIEN);
335
336 timo = 0;
337 for (;;) {
338 control = gttwsi_read_4(sc, TWSI_CONTROL);
339 if (control & CONTROL_IFLG)
340 break;
341 if (!(flags & I2C_F_POLL)) {
342 error = cv_timedwait(&sc->sc_cv, &sc->sc_mtx, hz);
343 if (error) {
344 break;
345 }
346 } else {
347 DELAY(TWSI_RETRY_DELAY);
348 if (timo++ > 1000000) /* 1sec */
349 break;
350 }
351 }
352 if ((control & CONTROL_IFLG) == 0) {
353 /*
354 * error is set by the cv_timedwait() call above in the
355 * non-polled case.
356 */
357 if (flags & I2C_F_POLL) {
358 error = EWOULDBLOCK;
359 } else {
360 KASSERT(error != 0);
361 }
362 aprint_error_dev(sc->sc_dev,
363 "gttwsi_wait(): %s timeout%s, control=0x%x, error=%d\n",
364 what, (flags & I2C_F_POLL) ? " (polled)" : "",
365 control, error);
366 goto end;
367 }
368 status = gttwsi_read_4(sc, TWSI_STATUS);
369 if (status != expect) {
370 /*
371 * In the case of probing for a device, we are expecting
372 * 2 different status codes: the ACK case (device exists),
373 * or the NACK case (device does not exist). We don't
374 * need to report an error in the later case.
375 */
376 if (alt != 0 && status != alt)
377 aprint_error_dev(sc->sc_dev,
378 "unexpected status 0x%x: expect 0x%x\n", status,
379 expect);
380 error = EIO;
381 }
382 end:
383 mutex_exit(&sc->sc_mtx);
384 return error;
385 }
386