diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-piix4.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-piix4.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c index c2268cdf38e8..c21ca7bf2efe 100644 --- a/drivers/i2c/busses/i2c-piix4.c +++ b/drivers/i2c/busses/i2c-piix4.c @@ -58,7 +58,7 @@ #define SMBSLVDAT (0xC + piix4_smba) /* count for request_region */ -#define SMBIOSIZE 8 +#define SMBIOSIZE 9 /* PCI Address Constants */ #define SMBBA 0x090 @@ -585,12 +585,33 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, u8 command, int size, union i2c_smbus_data *data) { struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap); + unsigned short piix4_smba = adapdata->smba; + int retries = MAX_TIMEOUT; + int smbslvcnt; u8 smba_en_lo; u8 port; int retval; mutex_lock(&piix4_mutex_sb800); + /* Request the SMBUS semaphore, avoid conflicts with the IMC */ + smbslvcnt = inb_p(SMBSLVCNT); + do { + outb_p(smbslvcnt | 0x10, SMBSLVCNT); + + /* Check the semaphore status */ + smbslvcnt = inb_p(SMBSLVCNT); + if (smbslvcnt & 0x10) + break; + + usleep_range(1000, 2000); + } while (--retries); + /* SMBus is still owned by the IMC, we give up */ + if (!retries) { + mutex_unlock(&piix4_mutex_sb800); + return -EBUSY; + } + outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX); smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1); @@ -604,6 +625,9 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr, outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1); + /* Release the semaphore */ + outb_p(smbslvcnt | 0x20, SMBSLVCNT); + mutex_unlock(&piix4_mutex_sb800); return retval; |