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tcp: remove check for condition that never happens
[freebsd/src.git] / sys / powerpc / powermac / kiic.c
blob1948b3248db7759961918168bb5d5e6be097d0cd
1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2001 Tsubai Masanari. 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. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 * NetBSD: ki2c.c,v 1.11 2007/12/06 17:00:33 ad Exp
28 * Id: ki2c.c,v 1.7 2002/10/05 09:56:05 tsubai Exp
29 */
30
31 /*
32 * Support routines for the Keywest I2C controller.
33 */
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/bus.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <machine/resource.h>
43 #include <machine/bus.h>
44 #include <sys/rman.h>
45
46 #include <dev/iicbus/iicbus.h>
47 #include <dev/iicbus/iiconf.h>
48 #include <dev/ofw/ofw_bus.h>
49 #include "iicbus_if.h"
50
51 /* Keywest I2C Register offsets */
52 #define MODE 0
53 #define CONTROL 1
54 #define STATUS 2
55 #define ISR 3
56 #define IER 4
57 #define ADDR 5
58 #define SUBADDR 6
59 #define DATA 7
60 #define REV 8
61
62 /* MODE */
63 #define I2C_SPEED 0x03 /* Speed mask */
64 #define I2C_100kHz 0x00
65 #define I2C_50kHz 0x01
66 #define I2C_25kHz 0x02
67 #define I2C_MODE 0x0c /* Mode mask */
68 #define I2C_DUMBMODE 0x00 /* Dumb mode */
69 #define I2C_STDMODE 0x04 /* Standard mode */
70 #define I2C_STDSUBMODE 0x08 /* Standard mode + sub address */
71 #define I2C_COMBMODE 0x0c /* Combined mode */
72 #define I2C_PORT 0xf0 /* Port mask */
73
74 /* CONTROL */
75 #define I2C_CT_AAK 0x01 /* Send AAK */
76 #define I2C_CT_ADDR 0x02 /* Send address(es) */
77 #define I2C_CT_STOP 0x04 /* Send STOP */
78 #define I2C_CT_START 0x08 /* Send START */
79
80 /* STATUS */
81 #define I2C_ST_BUSY 0x01 /* Busy */
82 #define I2C_ST_LASTAAK 0x02 /* Last AAK */
83 #define I2C_ST_LASTRW 0x04 /* Last R/W */
84 #define I2C_ST_SDA 0x08 /* SDA */
85 #define I2C_ST_SCL 0x10 /* SCL */
86
87 /* ISR/IER */
88 #define I2C_INT_DATA 0x01 /* Data byte sent/received */
89 #define I2C_INT_ADDR 0x02 /* Address sent */
90 #define I2C_INT_STOP 0x04 /* STOP condition sent */
91 #define I2C_INT_START 0x08 /* START condition sent */
92
93 /* I2C flags */
94 #define I2C_BUSY 0x01
95 #define I2C_READING 0x02
96 #define I2C_ERROR 0x04
97 #define I2C_SELECTED 0x08
98
99 struct kiic_softc {
100 device_t sc_dev;
101 phandle_t sc_node;
102 struct mtx sc_mutex;
103 struct resource *sc_reg;
104 int sc_irqrid;
105 struct resource *sc_irq;
106 void *sc_ih;
107 u_int sc_regstep;
108 u_int sc_flags;
109 u_char *sc_data;
110 int sc_resid;
111 uint16_t sc_i2c_base;
112 device_t sc_iicbus;
113 };
114
115 static int kiic_probe(device_t dev);
116 static int kiic_attach(device_t dev);
117 static void kiic_writereg(struct kiic_softc *sc, u_int, u_int);
118 static u_int kiic_readreg(struct kiic_softc *, u_int);
119 static void kiic_setport(struct kiic_softc *, u_int);
120 static void kiic_setmode(struct kiic_softc *, u_int);
121 static void kiic_setspeed(struct kiic_softc *, u_int);
122 static void kiic_intr(void *xsc);
123 static int kiic_transfer(device_t dev, struct iic_msg *msgs,
124 uint32_t nmsgs);
125 static phandle_t kiic_get_node(device_t bus, device_t dev);
126
127 static device_method_t kiic_methods[] = {
128 /* device interface */
129 DEVMETHOD(device_probe, kiic_probe),
130 DEVMETHOD(device_attach, kiic_attach),
131
132 /* iicbus interface */
133 DEVMETHOD(iicbus_callback, iicbus_null_callback),
134 DEVMETHOD(iicbus_transfer, kiic_transfer),
135
136 /* ofw_bus interface */
137 DEVMETHOD(ofw_bus_get_node, kiic_get_node),
138 { 0, 0 }
139 };
140
141 static driver_t kiic_driver = {
142 "iichb",
143 kiic_methods,
144 sizeof(struct kiic_softc)
145 };
146
147 DRIVER_MODULE(kiic, macio, kiic_driver, 0, 0);
148 DRIVER_MODULE(kiic, unin, kiic_driver, 0, 0);
149
150 static int
151 kiic_probe(device_t self)
152 {
153 const char *name;
154
155 name = ofw_bus_get_name(self);
156 if (name && strcmp(name, "i2c") == 0) {
157 device_set_desc(self, "Keywest I2C controller");
158 return (0);
159 }
160
161 return (ENXIO);
162 }
163
164 static int
165 kiic_attach(device_t self)
166 {
167 struct kiic_softc *sc = device_get_softc(self);
168 int rid, rate;
169 phandle_t node;
170 char name[64];
171
172 bzero(sc, sizeof(*sc));
173 sc->sc_dev = self;
174
175 node = ofw_bus_get_node(self);
176 if (node == 0 || node == -1) {
177 return (EINVAL);
178 }
179
180 rid = 0;
181 sc->sc_reg = bus_alloc_resource_any(self, SYS_RES_MEMORY,
182 &rid, RF_ACTIVE);
183 if (sc->sc_reg == NULL) {
184 return (ENOMEM);
185 }
186
187 if (OF_getencprop(node, "AAPL,i2c-rate", &rate, 4) != 4) {
188 device_printf(self, "cannot get i2c-rate\n");
189 return (ENXIO);
190 }
191 if (OF_getencprop(node, "AAPL,address-step", &sc->sc_regstep, 4) != 4) {
192 device_printf(self, "unable to find i2c address step\n");
193 return (ENXIO);
194 }
195
196 /*
197 * Some Keywest I2C devices have their children attached directly
198 * underneath them. Some have a single 'iicbus' child with the
199 * devices underneath that. Sort this out, and make sure that the
200 * OFW I2C layer has the correct node.
201 *
202 * Note: the I2C children of the Uninorth bridges have two ports.
203 * In general, the port is designated in the 9th bit of the I2C
204 * address. However, for kiic devices with children attached below
205 * an i2c-bus node, the port is indicated in the 'reg' property
206 * of the i2c-bus node.
207 */
208
209 sc->sc_node = node;
210
211 node = OF_child(node);
212 if (OF_getprop(node, "name", name, sizeof(name)) > 0) {
213 if (strcmp(name,"i2c-bus") == 0) {
214 phandle_t reg;
215 if (OF_getprop(node, "reg", &reg, sizeof(reg)) > 0)
216 sc->sc_i2c_base = reg << 8;
217
218 sc->sc_node = node;
219 }
220 }
221
222 mtx_init(&sc->sc_mutex, "kiic", NULL, MTX_DEF);
223
224 sc->sc_irq = bus_alloc_resource_any(self, SYS_RES_IRQ, &sc->sc_irqrid,
225 RF_ACTIVE);
226 bus_setup_intr(self, sc->sc_irq, INTR_TYPE_MISC | INTR_MPSAFE, NULL,
227 kiic_intr, sc, &sc->sc_ih);
228
229 kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
230 kiic_writereg(sc, STATUS, 0);
231 kiic_writereg(sc, IER, 0);
232
233 kiic_setmode(sc, I2C_STDMODE);
234 kiic_setspeed(sc, I2C_100kHz); /* XXX rate */
235
236 kiic_writereg(sc, IER, I2C_INT_DATA | I2C_INT_ADDR | I2C_INT_STOP);
237
238 if (bootverbose)
239 device_printf(self, "Revision: %02X\n", kiic_readreg(sc, REV));
240
241 /* Add the IIC bus layer */
242 sc->sc_iicbus = device_add_child(self, "iicbus", DEVICE_UNIT_ANY);
243
244 bus_attach_children(self);
245 return (0);
246 }
247
248 static void
249 kiic_writereg(struct kiic_softc *sc, u_int reg, u_int val)
250 {
251 bus_write_4(sc->sc_reg, sc->sc_regstep * reg, val);
252 DELAY(100); /* register access delay */
253 }
254
255 static u_int
256 kiic_readreg(struct kiic_softc *sc, u_int reg)
257 {
258 return bus_read_4(sc->sc_reg, sc->sc_regstep * reg) & 0xff;
259 }
260
261 static void
262 kiic_setmode(struct kiic_softc *sc, u_int mode)
263 {
264 u_int x;
265
266 KASSERT((mode & ~I2C_MODE) == 0, ("bad mode"));
267 x = kiic_readreg(sc, MODE);
268 x &= ~I2C_MODE;
269 x |= mode;
270 kiic_writereg(sc, MODE, x);
271 }
272
273 static void
274 kiic_setport(struct kiic_softc *sc, u_int port)
275 {
276 u_int x;
277
278 KASSERT(port == 1 || port == 0, ("bad port"));
279 x = kiic_readreg(sc, MODE);
280 x &= ~I2C_PORT;
281 x |= (port << 4);
282 kiic_writereg(sc, MODE, x);
283 }
284
285 static void
286 kiic_setspeed(struct kiic_softc *sc, u_int speed)
287 {
288 u_int x;
289
290 KASSERT((speed & ~I2C_SPEED) == 0, ("bad speed"));
291 x = kiic_readreg(sc, MODE);
292 x &= ~I2C_SPEED;
293 x |= speed;
294 kiic_writereg(sc, MODE, x);
295 }
296
297 static void
298 kiic_intr(void *xsc)
299 {
300 struct kiic_softc *sc = xsc;
301 u_int isr;
302 uint32_t x;
303
304 mtx_lock(&sc->sc_mutex);
305 isr = kiic_readreg(sc, ISR);
306
307 if (isr & I2C_INT_ADDR) {
308 sc->sc_flags |= I2C_SELECTED;
309
310 if (sc->sc_flags & I2C_READING) {
311 if (sc->sc_resid > 1) {
312 x = kiic_readreg(sc, CONTROL);
313 x |= I2C_CT_AAK;
314 kiic_writereg(sc, CONTROL, x);
315 }
316 } else {
317 kiic_writereg(sc, DATA, *sc->sc_data++);
318 sc->sc_resid--;
319 }
320 }
321
322 if (isr & I2C_INT_DATA) {
323 if (sc->sc_flags & I2C_READING) {
324 if (sc->sc_resid > 0) {
325 *sc->sc_data++ = kiic_readreg(sc, DATA);
326 sc->sc_resid--;
327 }
328 if (sc->sc_resid == 0) /* done */
329 kiic_writereg(sc, CONTROL, 0);
330 } else {
331 if (sc->sc_resid == 0) {
332 x = kiic_readreg(sc, CONTROL);
333 x |= I2C_CT_STOP;
334 kiic_writereg(sc, CONTROL, x);
335 } else {
336 kiic_writereg(sc, DATA, *sc->sc_data++);
337 sc->sc_resid--;
338 }
339 }
340 }
341
342 if (isr & I2C_INT_STOP) {
343 kiic_writereg(sc, CONTROL, 0);
344 sc->sc_flags &= ~I2C_SELECTED;
345 wakeup(sc->sc_dev);
346 }
347
348 kiic_writereg(sc, ISR, isr);
349 mtx_unlock(&sc->sc_mutex);
350 }
351
352 static int
353 kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
354 {
355 struct kiic_softc *sc;
356 int i, x, timo, err;
357 uint16_t addr;
358 uint8_t subaddr;
359
360 sc = device_get_softc(dev);
361 timo = 100;
362 subaddr = 0;
363
364 mtx_lock(&sc->sc_mutex);
365
366 if (sc->sc_flags & I2C_BUSY)
367 mtx_sleep(dev, &sc->sc_mutex, 0, "kiic", timo);
368
369 if (sc->sc_flags & I2C_BUSY) {
370 mtx_unlock(&sc->sc_mutex);
371 return (ETIMEDOUT);
372 }
373
374 sc->sc_flags = I2C_BUSY;
375
376 /* Clear pending interrupts, and reset controller */
377 kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
378 kiic_writereg(sc, STATUS, 0);
379
380 for (i = 0; i < nmsgs; i++) {
381 if (msgs[i].flags & IIC_M_NOSTOP) {
382 if (msgs[i+1].flags & IIC_M_RD)
383 kiic_setmode(sc, I2C_COMBMODE);
384 else
385 kiic_setmode(sc, I2C_STDSUBMODE);
386 KASSERT(msgs[i].len == 1, ("oversize I2C message"));
387 subaddr = msgs[i].buf[0];
388 i++;
389 } else {
390 kiic_setmode(sc, I2C_STDMODE);
391 }
392
393 sc->sc_data = msgs[i].buf;
394 sc->sc_resid = msgs[i].len;
395 sc->sc_flags = I2C_BUSY;
396 addr = msgs[i].slave;
397 timo = 1000 + sc->sc_resid * 200;
398 timo += 100000;
399
400 if (msgs[i].flags & IIC_M_RD) {
401 sc->sc_flags |= I2C_READING;
402 addr |= 1;
403 }
404
405 addr |= sc->sc_i2c_base;
406
407 kiic_setport(sc, (addr & 0x100) >> 8);
408 kiic_writereg(sc, ADDR, addr & 0xff);
409 kiic_writereg(sc, SUBADDR, subaddr);
410
411 x = kiic_readreg(sc, CONTROL) | I2C_CT_ADDR;
412 kiic_writereg(sc, CONTROL, x);
413
414 err = mtx_sleep(dev, &sc->sc_mutex, 0, "kiic", timo);
415
416 msgs[i].len -= sc->sc_resid;
417
418 if ((sc->sc_flags & I2C_ERROR) || err == EWOULDBLOCK) {
419 device_printf(sc->sc_dev, "I2C error\n");
420 sc->sc_flags = 0;
421 mtx_unlock(&sc->sc_mutex);
422 return (EIO);
423 }
424 }
425
426 sc->sc_flags = 0;
427
428 mtx_unlock(&sc->sc_mutex);
429
430 return (0);
431 }
432
433 static phandle_t
434 kiic_get_node(device_t bus, device_t dev)
435 {
436 struct kiic_softc *sc;
437
438 sc = device_get_softc(bus);
439 /* We only have one child, the I2C bus, which needs our own node. */
440
441 return sc->sc_node;
442 }
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