hw/i2c/pm_smbus.c

   1 /*
   2  * PC SMBus implementation
   3  * splitted from acpi.c
   4  *
   5  * Copyright (c) 2006 Fabrice Bellard
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License version 2 as published by the Free Software Foundation.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see
  18  * <http://www.gnu.org/licenses/>.
  19  */
  20 #include "hw/hw.h"
  21 #include "hw/i386/pc.h"
  22 #include "hw/i2c/pm_smbus.h"
  23 #include "hw/i2c/smbus.h"
  24
  25 /* no save/load? */
  26
  27 #define SMBHSTSTS       0x00
  28 #define SMBHSTCNT       0x02
  29 #define SMBHSTCMD       0x03
  30 #define SMBHSTADD       0x04
  31 #define SMBHSTDAT0      0x05
  32 #define SMBHSTDAT1      0x06
  33 #define SMBBLKDAT       0x07
  34
  35 //#define DEBUG
  36
  37 #ifdef DEBUG
  38 # define SMBUS_DPRINTF(format, ...)     printf(format, ## __VA_ARGS__)
  39 #else
  40 # define SMBUS_DPRINTF(format, ...)     do { } while (0)
  41 #endif
  42
  43
  44 static void smb_transaction(PMSMBus *s)
  45 {
  46     uint8_t prot = (s->smb_ctl >> 2) & 0x07;
  47     uint8_t read = s->smb_addr & 0x01;
  48     uint8_t cmd = s->smb_cmd;
  49     uint8_t addr = s->smb_addr >> 1;
  50     i2c_bus *bus = s->smbus;
  51
  52     SMBUS_DPRINTF("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot);
  53     switch(prot) {
  54     case 0x0:
  55         smbus_quick_command(bus, addr, read);
  56         break;
  57     case 0x1:
  58         if (read) {
  59             s->smb_data0 = smbus_receive_byte(bus, addr);
  60         } else {
  61             smbus_send_byte(bus, addr, cmd);
  62         }
  63         break;
  64     case 0x2:
  65         if (read) {
  66             s->smb_data0 = smbus_read_byte(bus, addr, cmd);
  67         } else {
  68             smbus_write_byte(bus, addr, cmd, s->smb_data0);
  69         }
  70         break;
  71     case 0x3:
  72         if (read) {
  73             uint16_t val;
  74             val = smbus_read_word(bus, addr, cmd);
  75             s->smb_data0 = val;
  76             s->smb_data1 = val >> 8;
  77         } else {
  78             smbus_write_word(bus, addr, cmd, (s->smb_data1 << 8) | s->smb_data0);
  79         }
  80         break;
  81     case 0x5:
  82         if (read) {
  83             s->smb_data0 = smbus_read_block(bus, addr, cmd, s->smb_data);
  84         } else {
  85             smbus_write_block(bus, addr, cmd, s->smb_data, s->smb_data0);
  86         }
  87         break;
  88     default:
  89         goto error;
  90     }
  91     return;
  92
  93   error:
  94     s->smb_stat |= 0x04;
  95 }
  96
  97 static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
  98                               unsigned width)
  99 {
 100     PMSMBus *s = opaque;
 101
 102     SMBUS_DPRINTF("SMB writeb port=0x%04x val=0x%02x\n", addr, val);
 103     switch(addr) {
 104     case SMBHSTSTS:
 105         s->smb_stat = 0;
 106         s->smb_index = 0;
 107         break;
 108     case SMBHSTCNT:
 109         s->smb_ctl = val;
 110         if (val & 0x40)
 111             smb_transaction(s);
 112         break;
 113     case SMBHSTCMD:
 114         s->smb_cmd = val;
 115         break;
 116     case SMBHSTADD:
 117         s->smb_addr = val;
 118         break;
 119     case SMBHSTDAT0:
 120         s->smb_data0 = val;
 121         break;
 122     case SMBHSTDAT1:
 123         s->smb_data1 = val;
 124         break;
 125     case SMBBLKDAT:
 126         s->smb_data[s->smb_index++] = val;
 127         if (s->smb_index > 31)
 128             s->smb_index = 0;
 129         break;
 130     default:
 131         break;
 132     }
 133 }
 134
 135 static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
 136 {
 137     PMSMBus *s = opaque;
 138     uint32_t val;
 139
 140     switch(addr) {
 141     case SMBHSTSTS:
 142         val = s->smb_stat;
 143         break;
 144     case SMBHSTCNT:
 145         s->smb_index = 0;
 146         val = s->smb_ctl & 0x1f;
 147         break;
 148     case SMBHSTCMD:
 149         val = s->smb_cmd;
 150         break;
 151     case SMBHSTADD:
 152         val = s->smb_addr;
 153         break;
 154     case SMBHSTDAT0:
 155         val = s->smb_data0;
 156         break;
 157     case SMBHSTDAT1:
 158         val = s->smb_data1;
 159         break;
 160     case SMBBLKDAT:
 161         val = s->smb_data[s->smb_index++];
 162         if (s->smb_index > 31)
 163             s->smb_index = 0;
 164         break;
 165     default:
 166         val = 0;
 167         break;
 168     }
 169     SMBUS_DPRINTF("SMB readb port=0x%04x val=0x%02x\n", addr, val);
 170     return val;
 171 }
 172
 173 static const MemoryRegionOps pm_smbus_ops = {
 174     .read = smb_ioport_readb,
 175     .write = smb_ioport_writeb,
 176     .valid.min_access_size = 1,
 177     .valid.max_access_size = 1,
 178     .endianness = DEVICE_LITTLE_ENDIAN,
 179 };
 180
 181 void pm_smbus_init(DeviceState *parent, PMSMBus *smb)
 182 {
 183     smb->smbus = i2c_init_bus(parent, "i2c");
 184     memory_region_init_io(&smb->io, &pm_smbus_ops, smb, "pm-smbus", 64);
 185 }