diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-i801.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 08847e8b8998..eb3627f35d12 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -146,6 +146,7 @@ #define SMBHSTCFG_HST_EN 1 #define SMBHSTCFG_SMB_SMI_EN 2 #define SMBHSTCFG_I2C_EN 4 +#define SMBHSTCFG_SPD_WD 0x10 /* TCO configuration bits for TCOCTL */ #define TCOCTL_EN 0x0100 @@ -865,9 +866,16 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, block = 1; break; case I2C_SMBUS_I2C_BLOCK_DATA: - /* NB: page 240 of ICH5 datasheet shows that the R/#W - * bit should be cleared here, even when reading */ - outb_p((addr & 0x7f) << 1, SMBHSTADD(priv)); + /* + * NB: page 240 of ICH5 datasheet shows that the R/#W + * bit should be cleared here, even when reading. + * However if SPD Write Disable is set (Lynx Point and later), + * the read will fail if we don't set the R/#W bit. + */ + outb_p(((addr & 0x7f) << 1) | + ((priv->original_hstcfg & SMBHSTCFG_SPD_WD) ? + (read_write & 0x01) : 0), + SMBHSTADD(priv)); if (read_write == I2C_SMBUS_READ) { /* NB: page 240 of ICH5 datasheet also shows * that DATA1 is the cmd field when reading */ @@ -1573,6 +1581,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) /* Disable SMBus interrupt feature if SMBus using SMI# */ priv->features &= ~FEATURE_IRQ; } + if (temp & SMBHSTCFG_SPD_WD) + dev_info(&dev->dev, "SPD Write Disable is set\n"); /* Clear special mode bits */ if (priv->features & (FEATURE_SMBUS_PEC | FEATURE_BLOCK_BUFFER)) |