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 #include "qom/object.h"
35
36 //#define DEBUG
37
38 #define TYPE_SMBUS_EEPROM "smbus-eeprom"
39
40 OBJECT_DECLARE_SIMPLE_TYPE(SMBusEEPROMDevice, SMBUS_EEPROM)
41
42 #define SMBUS_EEPROM_SIZE 256
43
44 struct SMBusEEPROMDevice {
45 SMBusDevice smbusdev;
46 uint8_t data[SMBUS_EEPROM_SIZE];
47 uint8_t *init_data;
48 uint8_t offset;
49 bool accessed;
50 };
51
eeprom_receive_byte(SMBusDevice * dev)52 static 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
eeprom_write_data(SMBusDevice * dev,uint8_t * buf,uint8_t len)66 static 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
smbus_eeprom_vmstate_needed(void * opaque)89 static 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
98 static 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 = (const 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 */
smbus_eeprom_reset(DeviceState * dev)122 static 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
smbus_eeprom_realize(DeviceState * dev,Error ** errp)130 static void smbus_eeprom_realize(DeviceState *dev, Error **errp)
131 {
132 SMBusEEPROMDevice *eeprom = SMBUS_EEPROM(dev);
133
134 smbus_eeprom_reset(dev);
135 if (eeprom->init_data == NULL) {
136 error_setg(errp, "init_data cannot be NULL");
137 }
138 }
139
smbus_eeprom_class_initfn(ObjectClass * klass,void * data)140 static 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 device_class_set_legacy_reset(dc, smbus_eeprom_reset);
147 sc->receive_byte = eeprom_receive_byte;
148 sc->write_data = eeprom_write_data;
149 dc->vmsd = &vmstate_smbus_eeprom;
150 /* Reason: init_data */
151 dc->user_creatable = false;
152 }
153
154 static const TypeInfo smbus_eeprom_types[] = {
155 {
156 .name = TYPE_SMBUS_EEPROM,
157 .parent = TYPE_SMBUS_DEVICE,
158 .instance_size = sizeof(SMBusEEPROMDevice),
159 .class_init = smbus_eeprom_class_initfn,
160 },
161 };
162
DEFINE_TYPES(smbus_eeprom_types)163 DEFINE_TYPES(smbus_eeprom_types)
164
165 void smbus_eeprom_init_one(I2CBus *smbus, uint8_t address, uint8_t *eeprom_buf)
166 {
167 DeviceState *dev;
168
169 dev = qdev_new(TYPE_SMBUS_EEPROM);
170 qdev_prop_set_uint8(dev, "address", address);
171 /* FIXME: use an array of byte or block backend property? */
172 SMBUS_EEPROM(dev)->init_data = eeprom_buf;
173 qdev_realize_and_unref(dev, (BusState *)smbus, &error_fatal);
174 }
175
smbus_eeprom_init(I2CBus * smbus,int nb_eeprom,const uint8_t * eeprom_spd,int eeprom_spd_size)176 void smbus_eeprom_init(I2CBus *smbus, int nb_eeprom,
177 const uint8_t *eeprom_spd, int eeprom_spd_size)
178 {
179 int i;
180 /* XXX: make this persistent */
181
182 assert(nb_eeprom <= 8);
183 uint8_t *eeprom_buf = g_malloc0(8 * SMBUS_EEPROM_SIZE);
184 if (eeprom_spd_size > 0) {
185 memcpy(eeprom_buf, eeprom_spd, eeprom_spd_size);
186 }
187
188 for (i = 0; i < nb_eeprom; i++) {
189 smbus_eeprom_init_one(smbus, 0x50 + i,
190 eeprom_buf + (i * SMBUS_EEPROM_SIZE));
191 }
192 }
193
194 /* Generate SDRAM SPD EEPROM data describing a module of type and size */
spd_data_generate(enum sdram_type type,ram_addr_t ram_size)195 uint8_t *spd_data_generate(enum sdram_type type, ram_addr_t ram_size)
196 {
197 uint8_t *spd;
198 uint8_t nbanks;
199 uint16_t density;
200 uint32_t size;
201 int min_log2, max_log2, sz_log2;
202 int i;
203
204 switch (type) {
205 case SDR:
206 min_log2 = 2;
207 max_log2 = 9;
208 break;
209 case DDR:
210 min_log2 = 5;
211 max_log2 = 12;
212 break;
213 case DDR2:
214 min_log2 = 7;
215 max_log2 = 14;
216 break;
217 default:
218 g_assert_not_reached();
219 }
220 size = ram_size >> 20; /* work in terms of megabytes */
221 sz_log2 = 31 - clz32(size);
222 size = 1U << sz_log2;
223 assert(ram_size == size * MiB);
224 assert(sz_log2 >= min_log2);
225
226 nbanks = 1;
227 while (sz_log2 > max_log2 && nbanks < 8) {
228 sz_log2--;
229 nbanks *= 2;
230 }
231
232 assert(size == (1ULL << sz_log2) * nbanks);
233
234 /* split to 2 banks if possible to avoid a bug in MIPS Malta firmware */
235 if (nbanks == 1 && sz_log2 > min_log2) {
236 sz_log2--;
237 nbanks++;
238 }
239
240 density = 1ULL << (sz_log2 - 2);
241 switch (type) {
242 case DDR2:
243 density = (density & 0xe0) | (density >> 8 & 0x1f);
244 break;
245 case DDR:
246 density = (density & 0xf8) | (density >> 8 & 0x07);
247 break;
248 case SDR:
249 default:
250 density &= 0xff;
251 break;
252 }
253
254 spd = g_malloc0(256);
255 spd[0] = 128; /* data bytes in EEPROM */
256 spd[1] = 8; /* log2 size of EEPROM */
257 spd[2] = type;
258 spd[3] = 13; /* row address bits */
259 spd[4] = 10; /* column address bits */
260 spd[5] = (type == DDR2 ? nbanks - 1 : nbanks);
261 spd[6] = 64; /* module data width */
262 /* reserved / data width high */
263 spd[8] = 4; /* interface voltage level */
264 spd[9] = 0x25; /* highest CAS latency */
265 spd[10] = 1; /* access time */
266 /* DIMM configuration 0 = non-ECC */
267 spd[12] = 0x82; /* refresh requirements */
268 spd[13] = 8; /* primary SDRAM width */
269 /* ECC SDRAM width */
270 spd[15] = (type == DDR2 ? 0 : 1); /* reserved / delay for random col rd */
271 spd[16] = 12; /* burst lengths supported */
272 spd[17] = 4; /* banks per SDRAM device */
273 spd[18] = 12; /* ~CAS latencies supported */
274 spd[19] = (type == DDR2 ? 0 : 1); /* reserved / ~CS latencies supported */
275 spd[20] = 2; /* DIMM type / ~WE latencies */
276 spd[21] = (type < DDR2 ? 0x20 : 0); /* module features */
277 /* memory chip features */
278 spd[23] = 0x12; /* clock cycle time @ medium CAS latency */
279 /* data access time */
280 /* clock cycle time @ short CAS latency */
281 /* data access time */
282 spd[27] = 20; /* min. row precharge time */
283 spd[28] = 15; /* min. row active row delay */
284 spd[29] = 20; /* min. ~RAS to ~CAS delay */
285 spd[30] = 45; /* min. active to precharge time */
286 spd[31] = density;
287 spd[32] = 20; /* addr/cmd setup time */
288 spd[33] = 8; /* addr/cmd hold time */
289 spd[34] = 20; /* data input setup time */
290 spd[35] = 8; /* data input hold time */
291
292 /* checksum */
293 for (i = 0; i < 63; i++) {
294 spd[63] += spd[i];
295 }
296 return spd;
297 }
298