xref: /openbmc/qemu/hw/i2c/smbus_eeprom.c (revision 265b578c)
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 "hw/hw.h"
27 #include "hw/i2c/i2c.h"
28 #include "hw/i2c/smbus.h"
29 
30 //#define DEBUG
31 
32 typedef struct SMBusEEPROMDevice {
33     SMBusDevice smbusdev;
34     void *data;
35     uint8_t offset;
36 } SMBusEEPROMDevice;
37 
38 static void eeprom_quick_cmd(SMBusDevice *dev, uint8_t read)
39 {
40 #ifdef DEBUG
41     printf("eeprom_quick_cmd: addr=0x%02x read=%d\n", dev->i2c.address, read);
42 #endif
43 }
44 
45 static void eeprom_send_byte(SMBusDevice *dev, uint8_t val)
46 {
47     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
48 #ifdef DEBUG
49     printf("eeprom_send_byte: addr=0x%02x val=0x%02x\n",
50            dev->i2c.address, val);
51 #endif
52     eeprom->offset = val;
53 }
54 
55 static uint8_t eeprom_receive_byte(SMBusDevice *dev)
56 {
57     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
58     uint8_t *data = eeprom->data;
59     uint8_t val = data[eeprom->offset++];
60 #ifdef DEBUG
61     printf("eeprom_receive_byte: addr=0x%02x val=0x%02x\n",
62            dev->i2c.address, val);
63 #endif
64     return val;
65 }
66 
67 static void eeprom_write_data(SMBusDevice *dev, uint8_t cmd, uint8_t *buf, int len)
68 {
69     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
70     int n;
71 #ifdef DEBUG
72     printf("eeprom_write_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n",
73            dev->i2c.address, cmd, buf[0]);
74 #endif
75     /* A page write operation is not a valid SMBus command.
76        It is a block write without a length byte.  Fortunately we
77        get the full block anyway.  */
78     /* TODO: Should this set the current location?  */
79     if (cmd + len > 256)
80         n = 256 - cmd;
81     else
82         n = len;
83     memcpy(eeprom->data + cmd, buf, n);
84     len -= n;
85     if (len)
86         memcpy(eeprom->data, buf + n, len);
87 }
88 
89 static uint8_t eeprom_read_data(SMBusDevice *dev, uint8_t cmd, int n)
90 {
91     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
92     /* If this is the first byte then set the current position.  */
93     if (n == 0)
94         eeprom->offset = cmd;
95     /* As with writes, we implement block reads without the
96        SMBus length byte.  */
97     return eeprom_receive_byte(dev);
98 }
99 
100 static void smbus_eeprom_realize(DeviceState *dev, Error **errp)
101 {
102     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *)dev;
103 
104     eeprom->offset = 0;
105 }
106 
107 static Property smbus_eeprom_properties[] = {
108     DEFINE_PROP_PTR("data", SMBusEEPROMDevice, data),
109     DEFINE_PROP_END_OF_LIST(),
110 };
111 
112 static void smbus_eeprom_class_initfn(ObjectClass *klass, void *data)
113 {
114     DeviceClass *dc = DEVICE_CLASS(klass);
115     SMBusDeviceClass *sc = SMBUS_DEVICE_CLASS(klass);
116 
117     dc->realize = smbus_eeprom_realize;
118     sc->quick_cmd = eeprom_quick_cmd;
119     sc->send_byte = eeprom_send_byte;
120     sc->receive_byte = eeprom_receive_byte;
121     sc->write_data = eeprom_write_data;
122     sc->read_data = eeprom_read_data;
123     dc->props = smbus_eeprom_properties;
124     /* Reason: pointer property "data" */
125     dc->user_creatable = false;
126 }
127 
128 static const TypeInfo smbus_eeprom_info = {
129     .name          = "smbus-eeprom",
130     .parent        = TYPE_SMBUS_DEVICE,
131     .instance_size = sizeof(SMBusEEPROMDevice),
132     .class_init    = smbus_eeprom_class_initfn,
133 };
134 
135 static void smbus_eeprom_register_types(void)
136 {
137     type_register_static(&smbus_eeprom_info);
138 }
139 
140 type_init(smbus_eeprom_register_types)
141 
142 void smbus_eeprom_init_one(I2CBus *smbus, uint8_t address, uint8_t *eeprom_buf)
143 {
144     DeviceState *dev;
145 
146     dev = qdev_create((BusState *) smbus, "smbus-eeprom");
147     qdev_prop_set_uint8(dev, "address", address);
148     qdev_prop_set_ptr(dev, "data", eeprom_buf);
149     qdev_init_nofail(dev);
150 }
151 
152 void smbus_eeprom_init(I2CBus *smbus, int nb_eeprom,
153                        const uint8_t *eeprom_spd, int eeprom_spd_size)
154 {
155     int i;
156     uint8_t *eeprom_buf = g_malloc0(8 * 256); /* XXX: make this persistent */
157     if (eeprom_spd_size > 0) {
158         memcpy(eeprom_buf, eeprom_spd, eeprom_spd_size);
159     }
160 
161     for (i = 0; i < nb_eeprom; i++) {
162         smbus_eeprom_init_one(smbus, 0x50 + i, eeprom_buf + (i * 256));
163     }
164 }
165