1 /*
2 * PPC4xx I2C controller emulation
3 *
4 * Documentation: PPC405GP User's Manual, Chapter 22. IIC Bus Interface
5 *
6 * Copyright (c) 2007 Jocelyn Mayer
7 * Copyright (c) 2012 François Revol
8 * Copyright (c) 2016-2018 BALATON Zoltan
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 * THE SOFTWARE.
27 */
28
29 #include "qemu/osdep.h"
30 #include "qemu/log.h"
31 #include "qemu/module.h"
32 #include "hw/i2c/ppc4xx_i2c.h"
33 #include "hw/irq.h"
34
35 #define PPC4xx_I2C_MEM_SIZE 18
36
37 enum {
38 IIC_MDBUF = 0,
39 /* IIC_SDBUF = 2, */
40 IIC_LMADR = 4,
41 IIC_HMADR,
42 IIC_CNTL,
43 IIC_MDCNTL,
44 IIC_STS,
45 IIC_EXTSTS,
46 IIC_LSADR,
47 IIC_HSADR,
48 IIC_CLKDIV,
49 IIC_INTRMSK,
50 IIC_XFRCNT,
51 IIC_XTCNTLSS,
52 IIC_DIRECTCNTL
53 /* IIC_INTR */
54 };
55
56 #define IIC_CNTL_PT (1 << 0)
57 #define IIC_CNTL_READ (1 << 1)
58 #define IIC_CNTL_CHT (1 << 2)
59 #define IIC_CNTL_RPST (1 << 3)
60 #define IIC_CNTL_AMD (1 << 6)
61 #define IIC_CNTL_HMT (1 << 7)
62
63 #define IIC_MDCNTL_EINT (1 << 2)
64 #define IIC_MDCNTL_ESM (1 << 3)
65 #define IIC_MDCNTL_FMDB (1 << 6)
66
67 #define IIC_STS_PT (1 << 0)
68 #define IIC_STS_IRQA (1 << 1)
69 #define IIC_STS_ERR (1 << 2)
70 #define IIC_STS_MDBF (1 << 4)
71 #define IIC_STS_MDBS (1 << 5)
72
73 #define IIC_EXTSTS_XFRA (1 << 0)
74 #define IIC_EXTSTS_BCS_FREE (4 << 4)
75 #define IIC_EXTSTS_BCS_BUSY (5 << 4)
76
77 #define IIC_INTRMSK_EIMTC (1 << 0)
78 #define IIC_INTRMSK_EITA (1 << 1)
79 #define IIC_INTRMSK_EIIC (1 << 2)
80 #define IIC_INTRMSK_EIHE (1 << 3)
81
82 #define IIC_XTCNTLSS_SRST (1 << 0)
83
84 #define IIC_DIRECTCNTL_SDAC (1 << 3)
85 #define IIC_DIRECTCNTL_SCLC (1 << 2)
86 #define IIC_DIRECTCNTL_MSDA (1 << 1)
87 #define IIC_DIRECTCNTL_MSCL (1 << 0)
88
ppc4xx_i2c_reset(DeviceState * s)89 static void ppc4xx_i2c_reset(DeviceState *s)
90 {
91 PPC4xxI2CState *i2c = PPC4xx_I2C(s);
92
93 i2c->mdidx = -1;
94 memset(i2c->mdata, 0, ARRAY_SIZE(i2c->mdata));
95 /* [hl][ms]addr are not affected by reset */
96 i2c->cntl = 0;
97 i2c->mdcntl = 0;
98 i2c->sts = 0;
99 i2c->extsts = IIC_EXTSTS_BCS_FREE;
100 i2c->clkdiv = 0;
101 i2c->intrmsk = 0;
102 i2c->xfrcnt = 0;
103 i2c->xtcntlss = 0;
104 i2c->directcntl = 0xf; /* all non-reserved bits set */
105 }
106
ppc4xx_i2c_readb(void * opaque,hwaddr addr,unsigned int size)107 static uint64_t ppc4xx_i2c_readb(void *opaque, hwaddr addr, unsigned int size)
108 {
109 PPC4xxI2CState *i2c = PPC4xx_I2C(opaque);
110 uint64_t ret;
111 int i;
112
113 switch (addr) {
114 case IIC_MDBUF:
115 if (i2c->mdidx < 0) {
116 ret = 0xff;
117 break;
118 }
119 ret = i2c->mdata[0];
120 if (i2c->mdidx == 3) {
121 i2c->sts &= ~IIC_STS_MDBF;
122 } else if (i2c->mdidx == 0) {
123 i2c->sts &= ~IIC_STS_MDBS;
124 }
125 for (i = 0; i < i2c->mdidx; i++) {
126 i2c->mdata[i] = i2c->mdata[i + 1];
127 }
128 if (i2c->mdidx >= 0) {
129 i2c->mdidx--;
130 }
131 break;
132 case IIC_LMADR:
133 ret = i2c->lmadr;
134 break;
135 case IIC_HMADR:
136 ret = i2c->hmadr;
137 break;
138 case IIC_CNTL:
139 ret = i2c->cntl;
140 break;
141 case IIC_MDCNTL:
142 ret = i2c->mdcntl;
143 break;
144 case IIC_STS:
145 ret = i2c->sts;
146 break;
147 case IIC_EXTSTS:
148 ret = i2c_bus_busy(i2c->bus) ?
149 IIC_EXTSTS_BCS_BUSY : IIC_EXTSTS_BCS_FREE;
150 break;
151 case IIC_LSADR:
152 ret = i2c->lsadr;
153 break;
154 case IIC_HSADR:
155 ret = i2c->hsadr;
156 break;
157 case IIC_CLKDIV:
158 ret = i2c->clkdiv;
159 break;
160 case IIC_INTRMSK:
161 ret = i2c->intrmsk;
162 break;
163 case IIC_XFRCNT:
164 ret = i2c->xfrcnt;
165 break;
166 case IIC_XTCNTLSS:
167 ret = i2c->xtcntlss;
168 break;
169 case IIC_DIRECTCNTL:
170 ret = i2c->directcntl;
171 break;
172 default:
173 if (addr < PPC4xx_I2C_MEM_SIZE) {
174 qemu_log_mask(LOG_UNIMP, "%s: Unimplemented register 0x%"
175 HWADDR_PRIx "\n", __func__, addr);
176 } else {
177 qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad address 0x%"
178 HWADDR_PRIx "\n", __func__, addr);
179 }
180 ret = 0;
181 break;
182 }
183 return ret;
184 }
185
ppc4xx_i2c_writeb(void * opaque,hwaddr addr,uint64_t value,unsigned int size)186 static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
187 unsigned int size)
188 {
189 PPC4xxI2CState *i2c = opaque;
190
191 switch (addr) {
192 case IIC_MDBUF:
193 if (i2c->mdidx >= 3) {
194 break;
195 }
196 i2c->mdata[++i2c->mdidx] = value;
197 if (i2c->mdidx == 3) {
198 i2c->sts |= IIC_STS_MDBF;
199 } else if (i2c->mdidx == 0) {
200 i2c->sts |= IIC_STS_MDBS;
201 }
202 break;
203 case IIC_LMADR:
204 i2c->lmadr = value;
205 break;
206 case IIC_HMADR:
207 i2c->hmadr = value;
208 break;
209 case IIC_CNTL:
210 i2c->cntl = value & ~IIC_CNTL_PT;
211 if (value & IIC_CNTL_AMD) {
212 qemu_log_mask(LOG_UNIMP, "%s: only 7 bit addresses supported\n",
213 __func__);
214 }
215 if (value & IIC_CNTL_HMT && i2c_bus_busy(i2c->bus)) {
216 i2c_end_transfer(i2c->bus);
217 if (i2c->mdcntl & IIC_MDCNTL_EINT &&
218 i2c->intrmsk & IIC_INTRMSK_EIHE) {
219 i2c->sts |= IIC_STS_IRQA;
220 qemu_irq_raise(i2c->irq);
221 }
222 } else if (value & IIC_CNTL_PT) {
223 int recv = (value & IIC_CNTL_READ) >> 1;
224 int tct = value >> 4 & 3;
225 int i;
226
227 if (recv && (i2c->lmadr >> 1) >= 0x50 && (i2c->lmadr >> 1) < 0x58) {
228 /* smbus emulation does not like multi byte reads w/o restart */
229 value |= IIC_CNTL_RPST;
230 }
231
232 for (i = 0; i <= tct; i++) {
233 if (!i2c_bus_busy(i2c->bus)) {
234 i2c->extsts = IIC_EXTSTS_BCS_FREE;
235 if (i2c_start_transfer(i2c->bus, i2c->lmadr >> 1, recv)) {
236 i2c->sts |= IIC_STS_ERR;
237 i2c->extsts |= IIC_EXTSTS_XFRA;
238 break;
239 } else {
240 i2c->sts &= ~IIC_STS_ERR;
241 }
242 }
243 if (!(i2c->sts & IIC_STS_ERR)) {
244 if (recv) {
245 i2c->mdata[i] = i2c_recv(i2c->bus);
246 } else if (i2c_send(i2c->bus, i2c->mdata[i]) < 0) {
247 i2c->sts |= IIC_STS_ERR;
248 i2c->extsts |= IIC_EXTSTS_XFRA;
249 break;
250 }
251 }
252 if (value & IIC_CNTL_RPST || !(value & IIC_CNTL_CHT)) {
253 i2c_end_transfer(i2c->bus);
254 }
255 }
256 i2c->xfrcnt = i;
257 i2c->mdidx = i - 1;
258 if (recv && i2c->mdidx >= 0) {
259 i2c->sts |= IIC_STS_MDBS;
260 }
261 if (recv && i2c->mdidx == 3) {
262 i2c->sts |= IIC_STS_MDBF;
263 }
264 if (i && i2c->mdcntl & IIC_MDCNTL_EINT &&
265 i2c->intrmsk & IIC_INTRMSK_EIMTC) {
266 i2c->sts |= IIC_STS_IRQA;
267 qemu_irq_raise(i2c->irq);
268 }
269 }
270 break;
271 case IIC_MDCNTL:
272 i2c->mdcntl = value & 0x3d;
273 if (value & IIC_MDCNTL_ESM) {
274 qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
275 __func__);
276 }
277 if (value & IIC_MDCNTL_FMDB) {
278 i2c->mdidx = -1;
279 memset(i2c->mdata, 0, ARRAY_SIZE(i2c->mdata));
280 i2c->sts &= ~(IIC_STS_MDBF | IIC_STS_MDBS);
281 }
282 break;
283 case IIC_STS:
284 i2c->sts &= ~(value & 0x0a);
285 if (value & IIC_STS_IRQA && i2c->mdcntl & IIC_MDCNTL_EINT) {
286 qemu_irq_lower(i2c->irq);
287 }
288 break;
289 case IIC_EXTSTS:
290 i2c->extsts &= ~(value & 0x8f);
291 break;
292 case IIC_LSADR:
293 i2c->lsadr = value;
294 break;
295 case IIC_HSADR:
296 i2c->hsadr = value;
297 break;
298 case IIC_CLKDIV:
299 i2c->clkdiv = value;
300 break;
301 case IIC_INTRMSK:
302 i2c->intrmsk = value;
303 break;
304 case IIC_XFRCNT:
305 i2c->xfrcnt = value & 0x77;
306 break;
307 case IIC_XTCNTLSS:
308 i2c->xtcntlss &= ~(value & 0xf0);
309 if (value & IIC_XTCNTLSS_SRST) {
310 /* Is it actually a full reset? U-Boot sets some regs before */
311 ppc4xx_i2c_reset(DEVICE(i2c));
312 break;
313 }
314 break;
315 case IIC_DIRECTCNTL:
316 i2c->directcntl = value & (IIC_DIRECTCNTL_SDAC & IIC_DIRECTCNTL_SCLC);
317 i2c->directcntl |= (value & IIC_DIRECTCNTL_SCLC ? 1 : 0);
318 bitbang_i2c_set(&i2c->bitbang, BITBANG_I2C_SCL,
319 i2c->directcntl & IIC_DIRECTCNTL_MSCL);
320 i2c->directcntl |= bitbang_i2c_set(&i2c->bitbang, BITBANG_I2C_SDA,
321 (value & IIC_DIRECTCNTL_SDAC) != 0) << 1;
322 break;
323 default:
324 if (addr < PPC4xx_I2C_MEM_SIZE) {
325 qemu_log_mask(LOG_UNIMP, "%s: Unimplemented register 0x%"
326 HWADDR_PRIx "\n", __func__, addr);
327 } else {
328 qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad address 0x%"
329 HWADDR_PRIx "\n", __func__, addr);
330 }
331 break;
332 }
333 }
334
335 static const MemoryRegionOps ppc4xx_i2c_ops = {
336 .read = ppc4xx_i2c_readb,
337 .write = ppc4xx_i2c_writeb,
338 .valid.min_access_size = 1,
339 .valid.max_access_size = 4,
340 .impl.min_access_size = 1,
341 .impl.max_access_size = 1,
342 .endianness = DEVICE_NATIVE_ENDIAN,
343 };
344
ppc4xx_i2c_init(Object * o)345 static void ppc4xx_i2c_init(Object *o)
346 {
347 PPC4xxI2CState *s = PPC4xx_I2C(o);
348
349 memory_region_init_io(&s->iomem, OBJECT(s), &ppc4xx_i2c_ops, s,
350 TYPE_PPC4xx_I2C, PPC4xx_I2C_MEM_SIZE);
351 sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
352 sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
353 s->bus = i2c_init_bus(DEVICE(s), "i2c");
354 bitbang_i2c_init(&s->bitbang, s->bus);
355 }
356
ppc4xx_i2c_class_init(ObjectClass * klass,void * data)357 static void ppc4xx_i2c_class_init(ObjectClass *klass, void *data)
358 {
359 DeviceClass *dc = DEVICE_CLASS(klass);
360
361 dc->reset = ppc4xx_i2c_reset;
362 }
363
364 static const TypeInfo ppc4xx_i2c_type_info = {
365 .name = TYPE_PPC4xx_I2C,
366 .parent = TYPE_SYS_BUS_DEVICE,
367 .instance_size = sizeof(PPC4xxI2CState),
368 .instance_init = ppc4xx_i2c_init,
369 .class_init = ppc4xx_i2c_class_init,
370 };
371
ppc4xx_i2c_register_types(void)372 static void ppc4xx_i2c_register_types(void)
373 {
374 type_register_static(&ppc4xx_i2c_type_info);
375 }
376
377 type_init(ppc4xx_i2c_register_types)
378