hw/i2c/smbus_eeprom.c

   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 int smbus_eeprom_initfn(SMBusDevice *dev)
 101 {
 102     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *)dev;
 103
 104     eeprom->offset = 0;
 105     return 0;
 106 }
 107
 108 static Property smbus_eeprom_properties[] = {
 109     DEFINE_PROP_PTR("data", SMBusEEPROMDevice, data),
 110     DEFINE_PROP_END_OF_LIST(),
 111 };
 112
 113 static void smbus_eeprom_class_initfn(ObjectClass *klass, void *data)
 114 {
 115     DeviceClass *dc = DEVICE_CLASS(klass);
 116     SMBusDeviceClass *sc = SMBUS_DEVICE_CLASS(klass);
 117
 118     sc->init = smbus_eeprom_initfn;
 119     sc->quick_cmd = eeprom_quick_cmd;
 120     sc->send_byte = eeprom_send_byte;
 121     sc->receive_byte = eeprom_receive_byte;
 122     sc->write_data = eeprom_write_data;
 123     sc->read_data = eeprom_read_data;
 124     dc->props = smbus_eeprom_properties;
 125     /* Reason: pointer property "data" */
 126     dc->cannot_instantiate_with_device_add_yet = true;
 127 }
 128
 129 static const TypeInfo smbus_eeprom_info = {
 130     .name          = "smbus-eeprom",
 131     .parent        = TYPE_SMBUS_DEVICE,
 132     .instance_size = sizeof(SMBusEEPROMDevice),
 133     .class_init    = smbus_eeprom_class_initfn,
 134 };
 135
 136 static void smbus_eeprom_register_types(void)
 137 {
 138     type_register_static(&smbus_eeprom_info);
 139 }
 140
 141 type_init(smbus_eeprom_register_types)
 142
 143 void smbus_eeprom_init(I2CBus *smbus, int nb_eeprom,
 144                        const uint8_t *eeprom_spd, int eeprom_spd_size)
 145 {
 146     int i;
 147     uint8_t *eeprom_buf = g_malloc0(8 * 256); /* XXX: make this persistent */
 148     if (eeprom_spd_size > 0) {
 149         memcpy(eeprom_buf, eeprom_spd, eeprom_spd_size);
 150     }
 151
 152     for (i = 0; i < nb_eeprom; i++) {
 153         DeviceState *eeprom;
 154         eeprom = qdev_create((BusState *)smbus, "smbus-eeprom");
 155         qdev_prop_set_uint8(eeprom, "address", 0x50 + i);
 156         qdev_prop_set_ptr(eeprom, "data", eeprom_buf + (i * 256));
 157         qdev_init_nofail(eeprom);
 158     }
 159 }