1/*
2 * PPC4xx I2C controller emulation
3 *
4 * Copyright (c) 2007 Jocelyn Mayer
5 * Copyright (c) 2012 François Revol
6 * Copyright (c) 2016-2018 BALATON Zoltan
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27#include "qemu/osdep.h"
28#include "qemu/log.h"
29#include "qemu/module.h"
30#include "cpu.h"
31#include "hw/i2c/ppc4xx_i2c.h"
32#include "hw/irq.h"
33
34#define PPC4xx_I2C_MEM_SIZE 18
35
36enum {
37 IIC_MDBUF = 0,
38 /* IIC_SDBUF = 2, */
39 IIC_LMADR = 4,
40 IIC_HMADR,
41 IIC_CNTL,
42 IIC_MDCNTL,
43 IIC_STS,
44 IIC_EXTSTS,
45 IIC_LSADR,
46 IIC_HSADR,
47 IIC_CLKDIV,
48 IIC_INTRMSK,
49 IIC_XFRCNT,
50 IIC_XTCNTLSS,
51 IIC_DIRECTCNTL
52 /* IIC_INTR */
53};
54
55#define IIC_CNTL_PT (1 << 0)
56#define IIC_CNTL_READ (1 << 1)
57#define IIC_CNTL_CHT (1 << 2)
58#define IIC_CNTL_RPST (1 << 3)
59#define IIC_CNTL_AMD (1 << 6)
60#define IIC_CNTL_HMT (1 << 7)
61
62#define IIC_MDCNTL_EINT (1 << 2)
63#define IIC_MDCNTL_ESM (1 << 3)
64#define IIC_MDCNTL_FMDB (1 << 6)
65
66#define IIC_STS_PT (1 << 0)
67#define IIC_STS_IRQA (1 << 1)
68#define IIC_STS_ERR (1 << 2)
69#define IIC_STS_MDBF (1 << 4)
70#define IIC_STS_MDBS (1 << 5)
71
72#define IIC_EXTSTS_XFRA (1 << 0)
73#define IIC_EXTSTS_BCS_FREE (4 << 4)
74#define IIC_EXTSTS_BCS_BUSY (5 << 4)
75
76#define IIC_INTRMSK_EIMTC (1 << 0)
77#define IIC_INTRMSK_EITA (1 << 1)
78#define IIC_INTRMSK_EIIC (1 << 2)
79#define IIC_INTRMSK_EIHE (1 << 3)
80
81#define IIC_XTCNTLSS_SRST (1 << 0)
82
83#define IIC_DIRECTCNTL_SDAC (1 << 3)
84#define IIC_DIRECTCNTL_SCLC (1 << 2)
85#define IIC_DIRECTCNTL_MSDA (1 << 1)
86#define IIC_DIRECTCNTL_MSCL (1 << 0)
87
88static void ppc4xx_i2c_reset(DeviceState *s)
89{
90 PPC4xxI2CState *i2c = PPC4xx_I2C(s);
91
92 i2c->mdidx = -1;
93 memset(i2c->mdata, 0, ARRAY_SIZE(i2c->mdata));
94 /* [hl][ms]addr are not affected by reset */
95 i2c->cntl = 0;
96 i2c->mdcntl = 0;
97 i2c->sts = 0;
98 i2c->extsts = IIC_EXTSTS_BCS_FREE;
99 i2c->clkdiv = 0;
100 i2c->intrmsk = 0;
101 i2c->xfrcnt = 0;
102 i2c->xtcntlss = 0;
103 i2c->directcntl = 0xf; /* all non-reserved bits set */
104}
105
106static uint64_t ppc4xx_i2c_readb(void *opaque, hwaddr addr, unsigned int size)
107{
108 PPC4xxI2CState *i2c = PPC4xx_I2C(opaque);
109 uint64_t ret;
110 int i;
111
112 switch (addr) {
113 case IIC_MDBUF:
114 if (i2c->mdidx < 0) {
115 ret = 0xff;
116 break;
117 }
118 ret = i2c->mdata[0];
119 if (i2c->mdidx == 3) {
120 i2c->sts &= ~IIC_STS_MDBF;
121 } else if (i2c->mdidx == 0) {
122 i2c->sts &= ~IIC_STS_MDBS;
123 }
124 for (i = 0; i < i2c->mdidx; i++) {
125 i2c->mdata[i] = i2c->mdata[i + 1];
126 }
127 if (i2c->mdidx >= 0) {
128 i2c->mdidx--;
129 }
130 break;
131 case IIC_LMADR:
132 ret = i2c->lmadr;
133 break;
134 case IIC_HMADR:
135 ret = i2c->hmadr;
136 break;
137 case IIC_CNTL:
138 ret = i2c->cntl;
139 break;
140 case IIC_MDCNTL:
141 ret = i2c->mdcntl;
142 break;
143 case IIC_STS:
144 ret = i2c->sts;
145 break;
146 case IIC_EXTSTS:
147 ret = i2c_bus_busy(i2c->bus) ?
148 IIC_EXTSTS_BCS_BUSY : IIC_EXTSTS_BCS_FREE;
149 break;
150 case IIC_LSADR:
151 ret = i2c->lsadr;
152 break;
153 case IIC_HSADR:
154 ret = i2c->hsadr;
155 break;
156 case IIC_CLKDIV:
157 ret = i2c->clkdiv;
158 break;
159 case IIC_INTRMSK:
160 ret = i2c->intrmsk;
161 break;
162 case IIC_XFRCNT:
163 ret = i2c->xfrcnt;
164 break;
165 case IIC_XTCNTLSS:
166 ret = i2c->xtcntlss;
167 break;
168 case IIC_DIRECTCNTL:
169 ret = i2c->directcntl;
170 break;
171 default:
172 if (addr < PPC4xx_I2C_MEM_SIZE) {
173 qemu_log_mask(LOG_UNIMP, "%s: Unimplemented register 0x%"
174 HWADDR_PRIx "\n", __func__, addr);
175 } else {
176 qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad address 0x%"
177 HWADDR_PRIx "\n", __func__, addr);
178 }
179 ret = 0;
180 break;
181 }
182 return ret;
183}
184
185static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
186 unsigned int size)
187{
188 PPC4xxI2CState *i2c = opaque;
189
190 switch (addr) {
191 case IIC_MDBUF:
192 if (i2c->mdidx >= 3) {
193 break;
194 }
195 i2c->mdata[++i2c->mdidx] = value;
196 if (i2c->mdidx == 3) {
197 i2c->sts |= IIC_STS_MDBF;
198 } else if (i2c->mdidx == 0) {
199 i2c->sts |= IIC_STS_MDBS;
200 }
201 break;
202 case IIC_LMADR:
203 i2c->lmadr = value;
204 break;
205 case IIC_HMADR:
206 i2c->hmadr = value;
207 break;
208 case IIC_CNTL:
209 i2c->cntl = value & ~IIC_CNTL_PT;
210 if (value & IIC_CNTL_AMD) {
211 qemu_log_mask(LOG_UNIMP, "%s: only 7 bit addresses supported\n",
212 __func__);
213 }
214 if (value & IIC_CNTL_HMT && i2c_bus_busy(i2c->bus)) {
215 i2c_end_transfer(i2c->bus);
216 if (i2c->mdcntl & IIC_MDCNTL_EINT &&
217 i2c->intrmsk & IIC_INTRMSK_EIHE) {
218 i2c->sts |= IIC_STS_IRQA;
219 qemu_irq_raise(i2c->irq);
220 }
221 } else if (value & IIC_CNTL_PT) {
222 int recv = (value & IIC_CNTL_READ) >> 1;
223 int tct = value >> 4 & 3;
224 int i;
225
226 if (recv && (i2c->lmadr >> 1) >= 0x50 && (i2c->lmadr >> 1) < 0x58) {
227 /* smbus emulation does not like multi byte reads w/o restart */
228 value |= IIC_CNTL_RPST;
229 }
230
231 for (i = 0; i <= tct; i++) {
232 if (!i2c_bus_busy(i2c->bus)) {
233 i2c->extsts = IIC_EXTSTS_BCS_FREE;
234 if (i2c_start_transfer(i2c->bus, i2c->lmadr >> 1, recv)) {
235 i2c->sts |= IIC_STS_ERR;
236 i2c->extsts |= IIC_EXTSTS_XFRA;
237 break;
238 } else {
239 i2c->sts &= ~IIC_STS_ERR;
240 }
241 }
242 if (!(i2c->sts & IIC_STS_ERR) &&
243 i2c_send_recv(i2c->bus, &i2c->mdata[i], !recv)) {
244 i2c->sts |= IIC_STS_ERR;
245 i2c->extsts |= IIC_EXTSTS_XFRA;
246 break;
247 }
248 if (value & IIC_CNTL_RPST || !(value & IIC_CNTL_CHT)) {
249 i2c_end_transfer(i2c->bus);
250 }
251 }
252 i2c->xfrcnt = i;
253 i2c->mdidx = i - 1;
254 if (recv && i2c->mdidx >= 0) {
255 i2c->sts |= IIC_STS_MDBS;
256 }
257 if (recv && i2c->mdidx == 3) {
258 i2c->sts |= IIC_STS_MDBF;
259 }
260 if (i && i2c->mdcntl & IIC_MDCNTL_EINT &&
261 i2c->intrmsk & IIC_INTRMSK_EIMTC) {
262 i2c->sts |= IIC_STS_IRQA;
263 qemu_irq_raise(i2c->irq);
264 }
265 }
266 break;
267 case IIC_MDCNTL:
268 i2c->mdcntl = value & 0x3d;
269 if (value & IIC_MDCNTL_ESM) {
270 qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
271 __func__);
272 }
273 if (value & IIC_MDCNTL_FMDB) {
274 i2c->mdidx = -1;
275 memset(i2c->mdata, 0, ARRAY_SIZE(i2c->mdata));
276 i2c->sts &= ~(IIC_STS_MDBF | IIC_STS_MDBS);
277 }
278 break;
279 case IIC_STS:
280 i2c->sts &= ~(value & 0x0a);
281 if (value & IIC_STS_IRQA && i2c->mdcntl & IIC_MDCNTL_EINT) {
282 qemu_irq_lower(i2c->irq);
283 }
284 break;
285 case IIC_EXTSTS:
286 i2c->extsts &= ~(value & 0x8f);
287 break;
288 case IIC_LSADR:
289 i2c->lsadr = value;
290 break;
291 case IIC_HSADR:
292 i2c->hsadr = value;
293 break;
294 case IIC_CLKDIV:
295 i2c->clkdiv = value;
296 break;
297 case IIC_INTRMSK:
298 i2c->intrmsk = value;
299 break;
300 case IIC_XFRCNT:
301 i2c->xfrcnt = value & 0x77;
302 break;
303 case IIC_XTCNTLSS:
304 i2c->xtcntlss &= ~(value & 0xf0);
305 if (value & IIC_XTCNTLSS_SRST) {
306 /* Is it actually a full reset? U-Boot sets some regs before */
307 ppc4xx_i2c_reset(DEVICE(i2c));
308 break;
309 }
310 break;
311 case IIC_DIRECTCNTL:
312 i2c->directcntl = value & (IIC_DIRECTCNTL_SDAC & IIC_DIRECTCNTL_SCLC);
313 i2c->directcntl |= (value & IIC_DIRECTCNTL_SCLC ? 1 : 0);
314 bitbang_i2c_set(&i2c->bitbang, BITBANG_I2C_SCL,
315 i2c->directcntl & IIC_DIRECTCNTL_MSCL);
316 i2c->directcntl |= bitbang_i2c_set(&i2c->bitbang, BITBANG_I2C_SDA,
317 (value & IIC_DIRECTCNTL_SDAC) != 0) << 1;
318 break;
319 default:
320 if (addr < PPC4xx_I2C_MEM_SIZE) {
321 qemu_log_mask(LOG_UNIMP, "%s: Unimplemented register 0x%"
322 HWADDR_PRIx "\n", __func__, addr);
323 } else {
324 qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad address 0x%"
325 HWADDR_PRIx "\n", __func__, addr);
326 }
327 break;
328 }
329}
330
331static const MemoryRegionOps ppc4xx_i2c_ops = {
332 .read = ppc4xx_i2c_readb,
333 .write = ppc4xx_i2c_writeb,
334 .valid.min_access_size = 1,
335 .valid.max_access_size = 4,
336 .impl.min_access_size = 1,
337 .impl.max_access_size = 1,
338 .endianness = DEVICE_NATIVE_ENDIAN,
339};
340
341static void ppc4xx_i2c_init(Object *o)
342{
343 PPC4xxI2CState *s = PPC4xx_I2C(o);
344
345 memory_region_init_io(&s->iomem, OBJECT(s), &ppc4xx_i2c_ops, s,
346 TYPE_PPC4xx_I2C, PPC4xx_I2C_MEM_SIZE);
347 sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
348 sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
349 s->bus = i2c_init_bus(DEVICE(s), "i2c");
350 bitbang_i2c_init(&s->bitbang, s->bus);
351}
352
353static void ppc4xx_i2c_class_init(ObjectClass *klass, void *data)
354{
355 DeviceClass *dc = DEVICE_CLASS(klass);
356
357 dc->reset = ppc4xx_i2c_reset;
358}
359
360static const TypeInfo ppc4xx_i2c_type_info = {
361 .name = TYPE_PPC4xx_I2C,
362 .parent = TYPE_SYS_BUS_DEVICE,
363 .instance_size = sizeof(PPC4xxI2CState),
364 .instance_init = ppc4xx_i2c_init,
365 .class_init = ppc4xx_i2c_class_init,
366};
367
368static void ppc4xx_i2c_register_types(void)
369{
370 type_register_static(&ppc4xx_i2c_type_info);
371}
372
373type_init(ppc4xx_i2c_register_types)
374