1
2 /* $NetBSD: scmdi2c.c,v 1.2 2022/03/30 00:06:50 pgoyette Exp $ */
3
4 /*
5 * Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #include <sys/cdefs.h>
21 __KERNEL_RCSID(0, "$NetBSD: scmdi2c.c,v 1.2 2022/03/30 00:06:50 pgoyette Exp $");
22
23 /*
24 * I2C driver for the Sparkfun Serial motor controller.
25 * Uses the common code to do the actual work.
26 */
27
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/kernel.h>
31 #include <sys/device.h>
32 #include <sys/module.h>
33 #include <sys/conf.h>
34 #include <sys/sysctl.h>
35 #include <sys/mutex.h>
36 #include <sys/condvar.h>
37 #include <sys/pool.h>
38 #include <sys/kmem.h>
39
40 #include <dev/i2c/i2cvar.h>
41 #include <dev/spi/spivar.h>
42 #include <dev/ic/scmdreg.h>
43 #include <dev/ic/scmdvar.h>
44
45 extern struct cdevsw scmd_cdevsw;
46
47 extern void scmd_attach(struct scmd_sc *);
48
49 static int scmdi2c_poke(i2c_tag_t, i2c_addr_t, bool);
50 static int scmdi2c_match(device_t, cfdata_t, void *);
51 static void scmdi2c_attach(device_t, device_t, void *);
52 static int scmdi2c_detach(device_t, int);
53 static int scmdi2c_activate(device_t, enum devact);
54
55 #define SCMD_DEBUG
56 #ifdef SCMD_DEBUG
57 #define DPRINTF(s, l, x) \
58 do { \
59 if (l <= s->sc_scmddebug) \
60 printf x; \
61 } while (/*CONSTCOND*/0)
62 #else
63 #define DPRINTF(s, l, x)
64 #endif
65
66 CFATTACH_DECL_NEW(scmdi2c, sizeof(struct scmd_sc),
67 scmdi2c_match, scmdi2c_attach, scmdi2c_detach, scmdi2c_activate);
68
69 static int
scmdi2c_read_reg_direct(i2c_tag_t tag,i2c_addr_t addr,uint8_t reg,uint8_t * buf)70 scmdi2c_read_reg_direct(i2c_tag_t tag, i2c_addr_t addr, uint8_t reg,
71 uint8_t *buf)
72 {
73 return iic_exec(tag, I2C_OP_READ_WITH_STOP, addr, ®, 1, buf,
74 1, 0);
75 }
76
77 static int
scmdi2c_read_reg(struct scmd_sc * sc,uint8_t reg,uint8_t * buf)78 scmdi2c_read_reg(struct scmd_sc *sc, uint8_t reg, uint8_t *buf)
79 {
80 return scmdi2c_read_reg_direct(sc->sc_tag, sc->sc_addr, reg, buf);
81 }
82
83 static int
scmdi2c_write_reg_direct(i2c_tag_t tag,i2c_addr_t addr,uint8_t reg,uint8_t buf)84 scmdi2c_write_reg_direct(i2c_tag_t tag, i2c_addr_t addr, uint8_t reg,
85 uint8_t buf)
86 {
87 return iic_exec(tag, I2C_OP_WRITE_WITH_STOP, addr, ®, 1, &buf,
88 1, 0);
89 }
90
91 static int
scmdi2c_write_reg(struct scmd_sc * sc,uint8_t reg,uint8_t buf)92 scmdi2c_write_reg(struct scmd_sc *sc, uint8_t reg, uint8_t buf)
93 {
94 return scmdi2c_write_reg_direct(sc->sc_tag, sc->sc_addr, reg, buf);
95 }
96
97 static int
scmdi2c_acquire_bus(struct scmd_sc * sc)98 scmdi2c_acquire_bus(struct scmd_sc *sc)
99 {
100 return(iic_acquire_bus(sc->sc_tag, 0));
101 }
102
103 static void
scmdi2c_release_bus(struct scmd_sc * sc)104 scmdi2c_release_bus(struct scmd_sc *sc)
105 {
106 iic_release_bus(sc->sc_tag, 0);
107 }
108
109 static int
scmdi2c_poke(i2c_tag_t tag,i2c_addr_t addr,bool matchdebug)110 scmdi2c_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug)
111 {
112 uint8_t reg = SCMD_REG_ID;
113 uint8_t buf;
114 int error;
115
116 error = scmdi2c_read_reg_direct(tag, addr, reg, &buf);
117 if (matchdebug) {
118 printf("poke X 1: %d %02x %d\n", addr, buf, error);
119 }
120 return error;
121 }
122
123 static int
scmdi2c_match(device_t parent,cfdata_t match,void * aux)124 scmdi2c_match(device_t parent, cfdata_t match, void *aux)
125 {
126 struct i2c_attach_args *ia = aux;
127 int error, match_result;
128 const bool matchdebug = false;
129
130 if (iic_use_direct_match(ia, match, NULL, &match_result))
131 return match_result;
132
133 if (matchdebug) {
134 printf("Looking at ia_addr: %x\n",ia->ia_addr);
135 }
136
137 /* indirect config - check for configured address */
138 if (!(ia->ia_addr >= SCMD_LOW_I2C_ADDR &&
139 ia->ia_addr <= SCMD_HIGH_I2C_ADDR))
140 return 0;
141
142 /*
143 * Check to see if something is really at this i2c address.
144 * This will keep phantom devices from appearing
145 */
146 if (iic_acquire_bus(ia->ia_tag, 0) != 0) {
147 if (matchdebug)
148 printf("in match acquire bus failed\n");
149 return 0;
150 }
151
152 error = scmdi2c_poke(ia->ia_tag, ia->ia_addr, matchdebug);
153 iic_release_bus(ia->ia_tag, 0);
154
155 return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0;
156 }
157
158 static void
scmdi2c_attach(device_t parent,device_t self,void * aux)159 scmdi2c_attach(device_t parent, device_t self, void *aux)
160 {
161 struct scmd_sc *sc;
162 struct i2c_attach_args *ia;
163
164 ia = aux;
165 sc = device_private(self);
166
167 sc->sc_dev = self;
168 sc->sc_tag = ia->ia_tag;
169 sc->sc_addr = ia->ia_addr;
170 sc->sc_scmddebug = 0;
171 sc->sc_topaddr = 0xff;
172 sc->sc_opened = false;
173 sc->sc_dying = false;
174 sc->sc_func_acquire_bus = &scmdi2c_acquire_bus;
175 sc->sc_func_release_bus = &scmdi2c_release_bus;
176 sc->sc_func_read_register = &scmdi2c_read_reg;
177 sc->sc_func_write_register = &scmdi2c_write_reg;
178
179 mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);
180 mutex_init(&sc->sc_condmutex, MUTEX_DEFAULT, IPL_NONE);
181 mutex_init(&sc->sc_dying_mutex, MUTEX_DEFAULT, IPL_NONE);
182 cv_init(&sc->sc_condvar, "scmdi2ccv");
183 cv_init(&sc->sc_cond_dying, "scmdi2cdc");
184
185 scmd_attach(sc);
186
187 return;
188 }
189
190 static int
scmdi2c_detach(device_t self,int flags)191 scmdi2c_detach(device_t self, int flags)
192 {
193 struct scmd_sc *sc;
194
195 sc = device_private(self);
196
197 mutex_enter(&sc->sc_mutex);
198 sc->sc_dying = true;
199 /* If this is true we are still open, destroy the condvar */
200 if (sc->sc_opened) {
201 mutex_enter(&sc->sc_dying_mutex);
202 DPRINTF(sc, 2, ("%s: Will wait for anything to exit\n",
203 device_xname(sc->sc_dev)));
204 /* In the worst case this will time out after 5 seconds.
205 * It really should not take that long for the drain / whatever
206 * to happen
207 */
208 cv_timedwait_sig(&sc->sc_cond_dying,
209 &sc->sc_dying_mutex, mstohz(5000));
210 mutex_exit(&sc->sc_dying_mutex);
211 cv_destroy(&sc->sc_cond_dying);
212 }
213 cv_destroy(&sc->sc_condvar);
214 mutex_exit(&sc->sc_mutex);
215
216 mutex_destroy(&sc->sc_mutex);
217 mutex_destroy(&sc->sc_condmutex);
218
219 return 0;
220 }
221
222 int
scmdi2c_activate(device_t self,enum devact act)223 scmdi2c_activate(device_t self, enum devact act)
224 {
225 struct scmd_sc *sc = device_private(self);
226
227 switch (act) {
228 case DVACT_DEACTIVATE:
229 sc->sc_dying = true;
230 return 0;
231 default:
232 return EOPNOTSUPP;
233 }
234 }
235
236 MODULE(MODULE_CLASS_DRIVER, scmdi2c, "iic,scmd");
237
238 #ifdef _MODULE
239 /* Like other drivers, we do this because the scmd common
240 * driver has the definitions already.
241 */
242 #undef CFDRIVER_DECL
243 #define CFDRIVER_DECL(name, class, attr)
244 #include "ioconf.c"
245 #endif
246
247 static int
scmdi2c_modcmd(modcmd_t cmd,void * opaque)248 scmdi2c_modcmd(modcmd_t cmd, void *opaque)
249 {
250 #ifdef _MODULE
251 int error = 0;
252 static struct cfdriver * const no_cfdriver_vec[] = { NULL };
253 #endif
254
255 switch (cmd) {
256 case MODULE_CMD_INIT:
257 #ifdef _MODULE
258 /* I really do not understand why I had to do this this way.
259 * If I did not then the module would either not install when
260 * the SPI driver and hence the scmd dependent driver was compiled
261 * into the kernel, or it would not install if it was not.
262 * I suspect something is still not set up correctly somewhere, but
263 * I am at a lose to see what.
264 *
265 * The first config_init_component will fail if the SPI driver and the
266 * scmd dependent is in the kernel already, but the second one will work.
267 * Otherwise the other way around.
268 *
269 * This all manages to get this module set up in any situation.
270 */
271 error = config_init_component(cfdriver_ioconf_scmdi2c,
272 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c);
273 if (error) {
274 aprint_error("%s: Trying no_cfdriver_vec method: %d\n",
275 scmd_cd.cd_name, error);
276 error = config_init_component(no_cfdriver_vec,
277 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c);
278 }
279
280 return error;
281 #else
282 return 0;
283 #endif
284 case MODULE_CMD_FINI:
285 #ifdef _MODULE
286 /* See above.. same thing */
287 error = config_fini_component(cfdriver_ioconf_scmdi2c,
288 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c);
289 if (error) {
290 aprint_error("%s: Trying no_cfdriver_vec method: %d\n",
291 scmd_cd.cd_name, error);
292 error = config_fini_component(no_cfdriver_vec,
293 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c);
294 }
295
296 return error;
297 #else
298 return 0;
299 #endif
300 default:
301 return ENOTTY;
302 }
303 }
304