xref: /openbmc/qemu/hw/i2c/smbus_eeprom.c (revision 49ab747f)
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 "hw/hw.h"
26 #include "hw/i2c/i2c.h"
27 #include "hw/i2c/smbus.h"
28 
29 //#define DEBUG
30 
31 typedef struct SMBusEEPROMDevice {
32     SMBusDevice smbusdev;
33     void *data;
34     uint8_t offset;
35 } SMBusEEPROMDevice;
36 
37 static void eeprom_quick_cmd(SMBusDevice *dev, uint8_t read)
38 {
39 #ifdef DEBUG
40     printf("eeprom_quick_cmd: addr=0x%02x read=%d\n", dev->i2c.address, read);
41 #endif
42 }
43 
44 static void eeprom_send_byte(SMBusDevice *dev, uint8_t val)
45 {
46     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
47 #ifdef DEBUG
48     printf("eeprom_send_byte: addr=0x%02x val=0x%02x\n",
49            dev->i2c.address, val);
50 #endif
51     eeprom->offset = val;
52 }
53 
54 static uint8_t eeprom_receive_byte(SMBusDevice *dev)
55 {
56     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
57     uint8_t *data = eeprom->data;
58     uint8_t val = data[eeprom->offset++];
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 
66 static void eeprom_write_data(SMBusDevice *dev, uint8_t cmd, uint8_t *buf, int len)
67 {
68     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
69     int n;
70 #ifdef DEBUG
71     printf("eeprom_write_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n",
72            dev->i2c.address, cmd, buf[0]);
73 #endif
74     /* An page write operation is not a valid SMBus command.
75        It is a block write without a length byte.  Fortunately we
76        get the full block anyway.  */
77     /* TODO: Should this set the current location?  */
78     if (cmd + len > 256)
79         n = 256 - cmd;
80     else
81         n = len;
82     memcpy(eeprom->data + cmd, buf, n);
83     len -= n;
84     if (len)
85         memcpy(eeprom->data, buf + n, len);
86 }
87 
88 static uint8_t eeprom_read_data(SMBusDevice *dev, uint8_t cmd, int n)
89 {
90     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
91     /* If this is the first byte then set the current position.  */
92     if (n == 0)
93         eeprom->offset = cmd;
94     /* As with writes, we implement block reads without the
95        SMBus length byte.  */
96     return eeprom_receive_byte(dev);
97 }
98 
99 static int smbus_eeprom_initfn(SMBusDevice *dev)
100 {
101     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *)dev;
102 
103     eeprom->offset = 0;
104     return 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     sc->init = smbus_eeprom_initfn;
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 }
125 
126 static const TypeInfo smbus_eeprom_info = {
127     .name          = "smbus-eeprom",
128     .parent        = TYPE_SMBUS_DEVICE,
129     .instance_size = sizeof(SMBusEEPROMDevice),
130     .class_init    = smbus_eeprom_class_initfn,
131 };
132 
133 static void smbus_eeprom_register_types(void)
134 {
135     type_register_static(&smbus_eeprom_info);
136 }
137 
138 type_init(smbus_eeprom_register_types)
139 
140 void smbus_eeprom_init(i2c_bus *smbus, int nb_eeprom,
141                        const uint8_t *eeprom_spd, int eeprom_spd_size)
142 {
143     int i;
144     uint8_t *eeprom_buf = g_malloc0(8 * 256); /* XXX: make this persistent */
145     if (eeprom_spd_size > 0) {
146         memcpy(eeprom_buf, eeprom_spd, eeprom_spd_size);
147     }
148 
149     for (i = 0; i < nb_eeprom; i++) {
150         DeviceState *eeprom;
151         eeprom = qdev_create((BusState *)smbus, "smbus-eeprom");
152         qdev_prop_set_uint8(eeprom, "address", 0x50 + i);
153         qdev_prop_set_ptr(eeprom, "data", eeprom_buf + (i * 256));
154         qdev_init_nofail(eeprom);
155     }
156 }
157