1/*
2 * QEMU SMBus EEPROM device
3 *
4 * Copyright (c) 2007 Arastra, Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25#include "qemu/osdep.h"
26#include "qemu/units.h"
27#include "qapi/error.h"
28#include "hw/boards.h"
29#include "hw/i2c/i2c.h"
30#include "hw/i2c/smbus_slave.h"
31#include "hw/qdev-properties.h"
32#include "migration/vmstate.h"
33#include "hw/i2c/smbus_eeprom.h"
34
35//#define DEBUG
36
37#define TYPE_SMBUS_EEPROM "smbus-eeprom"
38
39#define SMBUS_EEPROM(obj) \
40 OBJECT_CHECK(SMBusEEPROMDevice, (obj), TYPE_SMBUS_EEPROM)
41
42#define SMBUS_EEPROM_SIZE 256
43
44typedef struct SMBusEEPROMDevice {
45 SMBusDevice smbusdev;
46 uint8_t data[SMBUS_EEPROM_SIZE];
47 void *init_data;
48 uint8_t offset;
49 bool accessed;
50} SMBusEEPROMDevice;
51
52static uint8_t eeprom_receive_byte(SMBusDevice *dev)
53{
54 SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
55 uint8_t *data = eeprom->data;
56 uint8_t val = data[eeprom->offset++];
57
58 eeprom->accessed = true;
59#ifdef DEBUG
60 printf("eeprom_receive_byte: addr=0x%02x val=0x%02x\n",
61 dev->i2c.address, val);
62#endif
63 return val;
64}
65
66static int eeprom_write_data(SMBusDevice *dev, uint8_t *buf, uint8_t len)
67{
68 SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
69 uint8_t *data = eeprom->data;
70
71 eeprom->accessed = true;
72#ifdef DEBUG
73 printf("eeprom_write_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n",
74 dev->i2c.address, buf[0], buf[1]);
75#endif
76 /* len is guaranteed to be > 0 */
77 eeprom->offset = buf[0];
78 buf++;
79 len--;
80
81 for (; len > 0; len--) {
82 data[eeprom->offset] = *buf++;
83 eeprom->offset = (eeprom->offset + 1) % SMBUS_EEPROM_SIZE;
84 }
85
86 return 0;
87}
88
89static bool smbus_eeprom_vmstate_needed(void *opaque)
90{
91 MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
92 SMBusEEPROMDevice *eeprom = opaque;
93
94 return (eeprom->accessed || smbus_vmstate_needed(&eeprom->smbusdev)) &&
95 !mc->smbus_no_migration_support;
96}
97
98static const VMStateDescription vmstate_smbus_eeprom = {
99 .name = "smbus-eeprom",
100 .version_id = 1,
101 .minimum_version_id = 1,
102 .needed = smbus_eeprom_vmstate_needed,
103 .fields = (VMStateField[]) {
104 VMSTATE_SMBUS_DEVICE(smbusdev, SMBusEEPROMDevice),
105 VMSTATE_UINT8_ARRAY(data, SMBusEEPROMDevice, SMBUS_EEPROM_SIZE),
106 VMSTATE_UINT8(offset, SMBusEEPROMDevice),
107 VMSTATE_BOOL(accessed, SMBusEEPROMDevice),
108 VMSTATE_END_OF_LIST()
109 }
110};
111
112/*
113 * Reset the EEPROM contents to the initial state on a reset. This
114 * isn't really how an EEPROM works, of course, but the general
115 * principle of QEMU is to restore function on reset to what it would
116 * be if QEMU was stopped and started.
117 *
118 * The proper thing to do would be to have a backing blockdev to hold
119 * the contents and restore that on startup, and not do this on reset.
120 * But until that time, act as if we had been stopped and restarted.
121 */
122static void smbus_eeprom_reset(DeviceState *dev)
123{
124 SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
125
126 memcpy(eeprom->data, eeprom->init_data, SMBUS_EEPROM_SIZE);
127 eeprom->offset = 0;
128}
129
130static void smbus_eeprom_realize(DeviceState *dev, Error **errp)
131{
132 smbus_eeprom_reset(dev);
133}
134
135static Property smbus_eeprom_properties[] = {
136 DEFINE_PROP_PTR("data", SMBusEEPROMDevice, init_data),
137 DEFINE_PROP_END_OF_LIST(),
138};
139
140static void smbus_eeprom_class_initfn(ObjectClass *klass, void *data)
141{
142 DeviceClass *dc = DEVICE_CLASS(klass);
143 SMBusDeviceClass *sc = SMBUS_DEVICE_CLASS(klass);
144
145 dc->realize = smbus_eeprom_realize;
146 dc->reset = smbus_eeprom_reset;
147 sc->receive_byte = eeprom_receive_byte;
148 sc->write_data = eeprom_write_data;
149 dc->props = smbus_eeprom_properties;
150 dc->vmsd = &vmstate_smbus_eeprom;
151 /* Reason: pointer property "data" */
152 dc->user_creatable = false;
153}
154
155static const TypeInfo smbus_eeprom_info = {
156 .name = TYPE_SMBUS_EEPROM,
157 .parent = TYPE_SMBUS_DEVICE,
158 .instance_size = sizeof(SMBusEEPROMDevice),
159 .class_init = smbus_eeprom_class_initfn,
160};
161
162static void smbus_eeprom_register_types(void)
163{
164 type_register_static(&smbus_eeprom_info);
165}
166
167type_init(smbus_eeprom_register_types)
168
169void smbus_eeprom_init_one(I2CBus *smbus, uint8_t address, uint8_t *eeprom_buf)
170{
171 DeviceState *dev;
172
173 dev = qdev_create((BusState *) smbus, TYPE_SMBUS_EEPROM);
174 qdev_prop_set_uint8(dev, "address", address);
175 qdev_prop_set_ptr(dev, "data", eeprom_buf);
176 qdev_init_nofail(dev);
177}
178
179void smbus_eeprom_init(I2CBus *smbus, int nb_eeprom,
180 const uint8_t *eeprom_spd, int eeprom_spd_size)
181{
182 int i;
183 /* XXX: make this persistent */
184
185 assert(nb_eeprom <= 8);
186 uint8_t *eeprom_buf = g_malloc0(8 * SMBUS_EEPROM_SIZE);
187 if (eeprom_spd_size > 0) {
188 memcpy(eeprom_buf, eeprom_spd, eeprom_spd_size);
189 }
190
191 for (i = 0; i < nb_eeprom; i++) {
192 smbus_eeprom_init_one(smbus, 0x50 + i,
193 eeprom_buf + (i * SMBUS_EEPROM_SIZE));
194 }
195}
196
197/* Generate SDRAM SPD EEPROM data describing a module of type and size */
198uint8_t *spd_data_generate(enum sdram_type type, ram_addr_t ram_size,
199 Error **errp)
200{
201 uint8_t *spd;
202 uint8_t nbanks;
203 uint16_t density;
204 uint32_t size;
205 int min_log2, max_log2, sz_log2;
206 int i;
207
208 switch (type) {
209 case SDR:
210 min_log2 = 2;
211 max_log2 = 9;
212 break;
213 case DDR:
214 min_log2 = 5;
215 max_log2 = 12;
216 break;
217 case DDR2:
218 min_log2 = 7;
219 max_log2 = 14;
220 break;
221 default:
222 g_assert_not_reached();
223 }
224 size = ram_size >> 20; /* work in terms of megabytes */
225 if (size < 4) {
226 error_setg(errp, "SDRAM size is too small");
227 return NULL;
228 }
229 sz_log2 = 31 - clz32(size);
230 size = 1U << sz_log2;
231 if (ram_size > size * MiB) {
232 error_setg(errp, "SDRAM size 0x"RAM_ADDR_FMT" is not a power of 2, "
233 "truncating to %u MB", ram_size, size);
234 }
235 if (sz_log2 < min_log2) {
236 error_setg(errp,
237 "Memory size is too small for SDRAM type, adjusting type");
238 if (size >= 32) {
239 type = DDR;
240 min_log2 = 5;
241 max_log2 = 12;
242 } else {
243 type = SDR;
244 min_log2 = 2;
245 max_log2 = 9;
246 }
247 }
248
249 nbanks = 1;
250 while (sz_log2 > max_log2 && nbanks < 8) {
251 sz_log2--;
252 nbanks++;
253 }
254
255 if (size > (1ULL << sz_log2) * nbanks) {
256 error_setg(errp, "Memory size is too big for SDRAM, truncating");
257 }
258
259 /* split to 2 banks if possible to avoid a bug in MIPS Malta firmware */
260 if (nbanks == 1 && sz_log2 > min_log2) {
261 sz_log2--;
262 nbanks++;
263 }
264
265 density = 1ULL << (sz_log2 - 2);
266 switch (type) {
267 case DDR2:
268 density = (density & 0xe0) | (density >> 8 & 0x1f);
269 break;
270 case DDR:
271 density = (density & 0xf8) | (density >> 8 & 0x07);
272 break;
273 case SDR:
274 default:
275 density &= 0xff;
276 break;
277 }
278
279 spd = g_malloc0(256);
280 spd[0] = 128; /* data bytes in EEPROM */
281 spd[1] = 8; /* log2 size of EEPROM */
282 spd[2] = type;
283 spd[3] = 13; /* row address bits */
284 spd[4] = 10; /* column address bits */
285 spd[5] = (type == DDR2 ? nbanks - 1 : nbanks);
286 spd[6] = 64; /* module data width */
287 /* reserved / data width high */
288 spd[8] = 4; /* interface voltage level */
289 spd[9] = 0x25; /* highest CAS latency */
290 spd[10] = 1; /* access time */
291 /* DIMM configuration 0 = non-ECC */
292 spd[12] = 0x82; /* refresh requirements */
293 spd[13] = 8; /* primary SDRAM width */
294 /* ECC SDRAM width */
295 spd[15] = (type == DDR2 ? 0 : 1); /* reserved / delay for random col rd */
296 spd[16] = 12; /* burst lengths supported */
297 spd[17] = 4; /* banks per SDRAM device */
298 spd[18] = 12; /* ~CAS latencies supported */
299 spd[19] = (type == DDR2 ? 0 : 1); /* reserved / ~CS latencies supported */
300 spd[20] = 2; /* DIMM type / ~WE latencies */
301 /* module features */
302 /* memory chip features */
303 spd[23] = 0x12; /* clock cycle time @ medium CAS latency */
304 /* data access time */
305 /* clock cycle time @ short CAS latency */
306 /* data access time */
307 spd[27] = 20; /* min. row precharge time */
308 spd[28] = 15; /* min. row active row delay */
309 spd[29] = 20; /* min. ~RAS to ~CAS delay */
310 spd[30] = 45; /* min. active to precharge time */
311 spd[31] = density;
312 spd[32] = 20; /* addr/cmd setup time */
313 spd[33] = 8; /* addr/cmd hold time */
314 spd[34] = 20; /* data input setup time */
315 spd[35] = 8; /* data input hold time */
316
317 /* checksum */
318 for (i = 0; i < 63; i++) {
319 spd[63] += spd[i];
320 }
321 return spd;
322}
323