xref: /freebsd/sys/compat/linuxkpi/common/src/linux_i2c.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * Copyright (c) 2021 Beckhoff Automation GmbH & Co. KG
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * 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 #include <sys/malloc.h>
32 
33 #include <dev/iicbus/iicbus.h>
34 #include <dev/iicbus/iiconf.h>
35 
36 #include <linux/device.h>
37 #include <linux/i2c.h>
38 #include <linux/i2c-algo-bit.h>
39 #include <linux/list.h>
40 #include <linux/pci.h>
41 
42 #include "iicbus_if.h"
43 #include "iicbb_if.h"
44 #include "lkpi_iic_if.h"
45 
46 static int lkpi_i2c_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs);
47 static int lkpi_i2c_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr);
48 
49 struct lkpi_iic_softc {
50 	device_t		iicbus;
51 	struct i2c_adapter	*adapter;
52 };
53 
54 static struct sx lkpi_sx_i2c;
55 
56 static void
57 lkpi_sysinit_i2c(void *arg __unused)
58 {
59 
60 	sx_init(&lkpi_sx_i2c, "lkpi-i2c");
61 }
62 
63 static void
64 lkpi_sysuninit_i2c(void *arg __unused)
65 {
66 
67 	sx_destroy(&lkpi_sx_i2c);
68 }
69 
70 SYSINIT(lkpi_i2c, SI_SUB_DRIVERS, SI_ORDER_ANY,
71     lkpi_sysinit_i2c, NULL);
72 SYSUNINIT(lkpi_i2c, SI_SUB_DRIVERS, SI_ORDER_ANY,
73     lkpi_sysuninit_i2c, NULL);
74 
75 static int
76 lkpi_iic_probe(device_t dev)
77 {
78 
79 	device_set_desc(dev, "LinuxKPI I2C");
80 	return (BUS_PROBE_NOWILDCARD);
81 }
82 
83 static int
84 lkpi_iic_attach(device_t dev)
85 {
86 	struct lkpi_iic_softc *sc;
87 
88 	sc = device_get_softc(dev);
89 	sc->iicbus = device_add_child(dev, "iicbus", -1);
90 	if (sc->iicbus == NULL) {
91 		device_printf(dev, "Couldn't add iicbus child, aborting\n");
92 		return (ENXIO);
93 	}
94 	bus_generic_attach(dev);
95 	return (0);
96 }
97 
98 static int
99 lkpi_iic_detach(device_t dev)
100 {
101 	struct lkpi_iic_softc *sc;
102 
103 	sc = device_get_softc(dev);
104 	if (sc->iicbus)
105 		device_delete_child(dev, sc->iicbus);
106 	return (0);
107 }
108 
109 static int
110 lkpi_iic_add_adapter(device_t dev, struct i2c_adapter *adapter)
111 {
112 	struct lkpi_iic_softc *sc;
113 
114 	sc = device_get_softc(dev);
115 	sc->adapter = adapter;
116 
117 	return (0);
118 }
119 
120 static struct i2c_adapter *
121 lkpi_iic_get_adapter(device_t dev)
122 {
123 	struct lkpi_iic_softc *sc;
124 
125 	sc = device_get_softc(dev);
126 	return (sc->adapter);
127 }
128 
129 static device_method_t lkpi_iic_methods[] = {
130 	/* device interface */
131 	DEVMETHOD(device_probe,		lkpi_iic_probe),
132 	DEVMETHOD(device_attach,	lkpi_iic_attach),
133 	DEVMETHOD(device_detach,	lkpi_iic_detach),
134 	DEVMETHOD(device_suspend,	bus_generic_suspend),
135 	DEVMETHOD(device_resume,	bus_generic_resume),
136 
137 	/* iicbus interface */
138 	DEVMETHOD(iicbus_transfer,	lkpi_i2c_transfer),
139 	DEVMETHOD(iicbus_reset,		lkpi_i2c_reset),
140 	DEVMETHOD(iicbus_callback,	iicbus_null_callback),
141 
142 	/* lkpi_iic interface */
143 	DEVMETHOD(lkpi_iic_add_adapter,	lkpi_iic_add_adapter),
144 	DEVMETHOD(lkpi_iic_get_adapter,	lkpi_iic_get_adapter),
145 
146 	DEVMETHOD_END
147 };
148 
149 driver_t lkpi_iic_driver = {
150 	"lkpi_iic",
151 	lkpi_iic_methods,
152 	sizeof(struct lkpi_iic_softc),
153 };
154 
155 DRIVER_MODULE(lkpi_iic, drmn, lkpi_iic_driver, 0, 0);
156 DRIVER_MODULE(lkpi_iic, drm, lkpi_iic_driver, 0, 0);
157 DRIVER_MODULE(iicbus, lkpi_iic, iicbus_driver, 0, 0);
158 MODULE_DEPEND(linuxkpi, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
159 
160 static int
161 lkpi_i2c_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
162 {
163 
164 	/* That doesn't seems to be supported in linux */
165 	return (0);
166 }
167 
168 static int i2c_check_for_quirks(struct i2c_adapter *adapter,
169     struct iic_msg *msgs, uint32_t nmsgs)
170 {
171 	const struct i2c_adapter_quirks *quirks;
172 	device_t dev;
173 	int i, max_nmsgs;
174 	bool check_len;
175 
176 	dev = adapter->dev.parent->bsddev;
177 	quirks = adapter->quirks;
178 	if (quirks == NULL)
179 		return (0);
180 
181 	check_len = true;
182 	max_nmsgs = quirks->max_num_msgs;
183 
184 	if (quirks->flags & I2C_AQ_COMB) {
185 		max_nmsgs = 2;
186 
187 		if (nmsgs == 2) {
188 			if (quirks->flags & I2C_AQ_COMB_WRITE_FIRST &&
189 			    msgs[0].flags & IIC_M_RD) {
190 				device_printf(dev,
191 				    "Error: "
192 				    "first combined message must be write\n");
193 				return (EOPNOTSUPP);
194 			}
195 			if (quirks->flags & I2C_AQ_COMB_READ_SECOND &&
196 			    !(msgs[1].flags & IIC_M_RD)) {
197 				device_printf(dev,
198 				    "Error: "
199 				    "second combined message must be read\n");
200 				return (EOPNOTSUPP);
201 			}
202 
203 			if (quirks->flags & I2C_AQ_COMB_SAME_ADDR &&
204 			    msgs[0].slave != msgs[1].slave) {
205 				device_printf(dev,
206 				    "Error: "
207 				    "combined message must be use the same "
208 				    "address\n");
209 				return (EOPNOTSUPP);
210 			}
211 
212 			if (quirks->max_comb_1st_msg_len &&
213 			    msgs[0].len > quirks->max_comb_1st_msg_len) {
214 				device_printf(dev,
215 				    "Error: "
216 				    "message too long: %hu > %hu max\n",
217 				    msgs[0].len,
218 				    quirks->max_comb_1st_msg_len);
219 				return (EOPNOTSUPP);
220 			}
221 			if (quirks->max_comb_2nd_msg_len &&
222 			    msgs[1].len > quirks->max_comb_2nd_msg_len) {
223 				device_printf(dev,
224 				    "Error: "
225 				    "message too long: %hu > %hu max\n",
226 				    msgs[1].len,
227 				    quirks->max_comb_2nd_msg_len);
228 				return (EOPNOTSUPP);
229 			}
230 
231 			check_len = false;
232 		}
233 	}
234 
235 	if (max_nmsgs && nmsgs > max_nmsgs) {
236 		device_printf(dev,
237 		    "Error: too many messages: %d > %d max\n",
238 		    nmsgs, max_nmsgs);
239 		return (EOPNOTSUPP);
240 	}
241 
242 	for (i = 0; i < nmsgs; i++) {
243 		if (msgs[i].flags & IIC_M_RD) {
244 			if (check_len && quirks->max_read_len &&
245 			    msgs[i].len > quirks->max_read_len) {
246 				device_printf(dev,
247 				    "Error: "
248 				    "message %d too long: %hu > %hu max\n",
249 				    i, msgs[i].len, quirks->max_read_len);
250 				return (EOPNOTSUPP);
251 			}
252 			if (quirks->flags & I2C_AQ_NO_ZERO_LEN_READ &&
253 			    msgs[i].len == 0) {
254 				device_printf(dev,
255 				    "Error: message %d of length 0\n", i);
256 				return (EOPNOTSUPP);
257 			}
258 		} else {
259 			if (check_len && quirks->max_write_len &&
260 			    msgs[i].len > quirks->max_write_len) {
261 				device_printf(dev,
262 				    "Message %d too long: %hu > %hu max\n",
263 				    i, msgs[i].len, quirks->max_write_len);
264 				return (EOPNOTSUPP);
265 			}
266 			if (quirks->flags & I2C_AQ_NO_ZERO_LEN_WRITE &&
267 			    msgs[i].len == 0) {
268 				device_printf(dev,
269 				    "Error: message %d of length 0\n", i);
270 				return (EOPNOTSUPP);
271 			}
272 		}
273 	}
274 
275 	return (0);
276 }
277 
278 static int
279 lkpi_i2c_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
280 {
281 	struct lkpi_iic_softc *sc;
282 	struct i2c_msg *linux_msgs;
283 	int i, ret = 0;
284 
285 	sc = device_get_softc(dev);
286 	if (sc->adapter == NULL)
287 		return (ENXIO);
288 	ret = i2c_check_for_quirks(sc->adapter, msgs, nmsgs);
289 	if (ret != 0)
290 		return (ret);
291 	linux_set_current(curthread);
292 
293 	linux_msgs = malloc(sizeof(struct i2c_msg) * nmsgs,
294 	    M_DEVBUF, M_WAITOK | M_ZERO);
295 
296 	for (i = 0; i < nmsgs; i++) {
297 		linux_msgs[i].addr = msgs[i].slave >> 1;
298 		linux_msgs[i].len = msgs[i].len;
299 		linux_msgs[i].buf = msgs[i].buf;
300 		if (msgs[i].flags & IIC_M_RD) {
301 			linux_msgs[i].flags |= I2C_M_RD;
302 			for (int j = 0; j < msgs[i].len; j++)
303 				msgs[i].buf[j] = 0;
304 		}
305 		if (msgs[i].flags & IIC_M_NOSTART)
306 			linux_msgs[i].flags |= I2C_M_NOSTART;
307 	}
308 	ret = i2c_transfer(sc->adapter, linux_msgs, nmsgs);
309 	free(linux_msgs, M_DEVBUF);
310 
311 	if (ret < 0)
312 		return (-ret);
313 	return (0);
314 }
315 
316 int
317 lkpi_i2c_add_adapter(struct i2c_adapter *adapter)
318 {
319 	device_t lkpi_iic;
320 	int error;
321 
322 	if (adapter->name[0] == '\0')
323 		return (-EINVAL);
324 	if (bootverbose)
325 		device_printf(adapter->dev.parent->bsddev,
326 		    "Adding i2c adapter %s\n", adapter->name);
327 	sx_xlock(&lkpi_sx_i2c);
328 	lkpi_iic = device_add_child(adapter->dev.parent->bsddev, "lkpi_iic", -1);
329 	if (lkpi_iic == NULL) {
330 		device_printf(adapter->dev.parent->bsddev, "Couldn't add lkpi_iic\n");
331 		sx_xunlock(&lkpi_sx_i2c);
332 		return (ENXIO);
333 	}
334 
335 	bus_topo_lock();
336 	error = bus_generic_attach(adapter->dev.parent->bsddev);
337 	bus_topo_unlock();
338 	if (error) {
339 		device_printf(adapter->dev.parent->bsddev,
340 		  "failed to attach child: error %d\n", error);
341 		sx_xunlock(&lkpi_sx_i2c);
342 		return (ENXIO);
343 	}
344 	LKPI_IIC_ADD_ADAPTER(lkpi_iic, adapter);
345 	sx_xunlock(&lkpi_sx_i2c);
346 	return (0);
347 }
348 
349 int
350 lkpi_i2c_del_adapter(struct i2c_adapter *adapter)
351 {
352 	device_t child;
353 	int unit, rv;
354 
355 	if (adapter == NULL)
356 		return (-EINVAL);
357 	if (bootverbose)
358 		device_printf(adapter->dev.parent->bsddev,
359 		    "Removing i2c adapter %s\n", adapter->name);
360 	sx_xlock(&lkpi_sx_i2c);
361 	unit = 0;
362 	while ((child = device_find_child(adapter->dev.parent->bsddev, "lkpi_iic", unit++)) != NULL) {
363 
364 		if (adapter == LKPI_IIC_GET_ADAPTER(child)) {
365 			bus_topo_lock();
366 			device_delete_child(adapter->dev.parent->bsddev, child);
367 			bus_topo_unlock();
368 			rv = 0;
369 			goto out;
370 		}
371 	}
372 
373 	unit = 0;
374 	while ((child = device_find_child(adapter->dev.parent->bsddev, "lkpi_iicbb", unit++)) != NULL) {
375 
376 		if (adapter == LKPI_IIC_GET_ADAPTER(child)) {
377 			bus_topo_lock();
378 			device_delete_child(adapter->dev.parent->bsddev, child);
379 			bus_topo_unlock();
380 			rv = 0;
381 			goto out;
382 		}
383 	}
384 	rv = -EINVAL;
385 out:
386 	sx_xunlock(&lkpi_sx_i2c);
387 	return (rv);
388 }
389