hw/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 "hw.h"
  26 #include "i2c.h"
  27 #include "smbus.h"
  28
  29 //#define DEBUG
  30
  31 typedef struct SMBusEEPROMDevice {
  32     SMBusDevice dev;
  33     uint8_t *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 val = eeprom->data[eeprom->offset++];
  58 #ifdef DEBUG
  59     printf("eeprom_receive_byte: addr=0x%02x val=0x%02x\n",
  60            dev->i2c.address, val);
  61 #endif
  62     return val;
  63 }
  64
  65 static void eeprom_write_data(SMBusDevice *dev, uint8_t cmd, uint8_t *buf, int len)
  66 {
  67     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
  68     int n;
  69 #ifdef DEBUG
  70     printf("eeprom_write_byte: addr=0x%02x cmd=0x%02x val=0x%02x\n",
  71            dev->i2c.address, cmd, buf[0]);
  72 #endif
  73     /* An page write operation is not a valid SMBus command.
  74        It is a block write without a length byte.  Fortunately we
  75        get the full block anyway.  */
  76     /* TODO: Should this set the current location?  */
  77     if (cmd + len > 256)
  78         n = 256 - cmd;
  79     else
  80         n = len;
  81     memcpy(eeprom->data + cmd, buf, n);
  82     len -= n;
  83     if (len)
  84         memcpy(eeprom->data, buf + n, len);
  85 }
  86
  87 static uint8_t eeprom_read_data(SMBusDevice *dev, uint8_t cmd, int n)
  88 {
  89     SMBusEEPROMDevice *eeprom = (SMBusEEPROMDevice *) dev;
  90     /* If this is the first byte then set the current position.  */
  91     if (n == 0)
  92         eeprom->offset = cmd;
  93     /* As with writes, we implement block reads without the
  94        SMBus length byte.  */
  95     return eeprom_receive_byte(dev);
  96 }
  97
  98 void smbus_eeprom_device_init(i2c_bus *bus, uint8_t addr, uint8_t *buf)
  99 {
 100     SMBusEEPROMDevice *eeprom;
 101
 102     eeprom = (SMBusEEPROMDevice *)smbus_device_init(bus, addr,
 103         sizeof(SMBusEEPROMDevice));
 104
 105     eeprom->dev.quick_cmd = eeprom_quick_cmd;
 106     eeprom->dev.send_byte = eeprom_send_byte;
 107     eeprom->dev.receive_byte = eeprom_receive_byte;
 108     eeprom->dev.write_data = eeprom_write_data;
 109     eeprom->dev.read_data = eeprom_read_data;
 110     eeprom->data = buf;
 111     eeprom->offset = 0;
 112 }