int do_smbus_read_byte(u32 mmio, u8 device, u8 address)
{
u8 byte;
if (smbus_wait_until_ready(mmio) < 0)
return -2; /* not ready */
/* set the command/address... */
smbus_write8(mmio, SMBHSTCMD, address & 0xff);
/* set the device I'm talking to */
smbus_write8(mmio, SMBHSTADDR, ((device & 0x7f) << 1) | 1);
byte = smbus_read8(mmio, SMBHSTCTRL);
byte &= ~SMBHST_CTRL_MODE_BITS; /* Clear [4:2] */
byte |= SMBHST_CTRL_STRT | SMBHST_CTRL_BDT_RW; /* set mode, start */
smbus_write8(mmio, SMBHSTCTRL, byte);
/* poll for transaction completion */
if (smbus_wait_until_done(mmio) < 0)
return -3; /* timeout or error */
/* read results of transaction */
byte = smbus_read8(mmio, SMBHSTDAT0);
return byte;
}
static int lsmbus_read_byte(struct device *dev, u8 address)
{
u16 device;
struct resource *res;
struct bus *pbus;
device = dev->path.i2c.device;
pbus = get_pbus_smbus(dev);
res = find_resource(pbus->dev, PCI_BASE_ADDRESS_4);
return smbus_read8(res->base, device, address);
}
static int smbus_wait_until_ready(u32 mmio)
{
u32 loops;
loops = SMBUS_TIMEOUT;
do {
u8 val;
val = smbus_read8(mmio, SMBHSTSTAT);
val &= SMBHST_STAT_VAL_BITS;
if (val == 0) { /* ready now */
return 0;
}
smbus_write8(mmio, SMBHSTSTAT, val);
} while (--loops);
return -2; /* time out */
}
static int smbus_wait_until_done(u32 mmio)
{
u32 loops;
loops = SMBUS_TIMEOUT;
do {
u8 val;
val = smbus_read8(mmio, SMBHSTSTAT);
val &= SMBHST_STAT_VAL_BITS; /* mask off reserved bits */
if (val & SMBHST_STAT_ERROR_BITS)
return -5; /* error */
if (val == SMBHST_STAT_NOERROR) {
smbus_write8(mmio, SMBHSTSTAT, val); /* clear sts */
return 0;
}
} while (--loops);
return -3; /* timeout */
}
int do_smbus_send_byte(u32 mmio, u8 device, u8 val)
{
u8 byte;
if (smbus_wait_until_ready(mmio) < 0)
return -2; /* not ready */
/* set the command... */
smbus_write8(mmio, SMBHSTDAT0, val);
/* set the device I'm talking to */
smbus_write8(mmio, SMBHSTADDR, ((device & 0x7f) << 1) | 0);
byte = smbus_read8(mmio, SMBHSTCTRL);
byte &= ~SMBHST_CTRL_MODE_BITS; /* Clear [4:2] */
byte |= SMBHST_CTRL_STRT | SMBHST_CTRL_BTE_RW; /* set mode, start */
smbus_write8(mmio, SMBHSTCTRL, byte);
/* poll for transaction completion */
if (smbus_wait_until_done(mmio) < 0)
return -3; /* timeout or error */
return 0;
}
u8 smbus_read_byte(u32 smbus_dev, u8 addr, u8 offset)
{
return smbus_read8(SMBUS_IO_BASE, addr, offset);
}
