It was observed the Host Clock Divider was not written by the driver. It was still set to (default) 0 which caused garbage on SMBus. This driver adds 2 parameters which are used to calculate the divider appropriately.
Signed-off-by: Alexander Stein <[email protected]> --- drivers/i2c/busses/i2c-isch.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c index 0682f8f..520bbd5 100644 --- a/drivers/i2c/busses/i2c-isch.c +++ b/drivers/i2c/busses/i2c-isch.c @@ -40,6 +40,7 @@ /* SCH SMBus address offsets */ #define SMBHSTCNT (0 + sch_smba) #define SMBHSTSTS (1 + sch_smba) +#define SMBHSTCLK (2 + sch_smba) #define SMBHSTADD (4 + sch_smba) /* TSA */ #define SMBHSTCMD (5 + sch_smba) #define SMBHSTDAT0 (6 + sch_smba) @@ -58,6 +59,8 @@ static unsigned short sch_smba; static struct i2c_adapter sch_adapter; +static int smbus_speed = 100; /* SMBus bus speed in Kbps */ +static int backbone_speed = 33000; /* backbone speed in KHz */ /* * Start the i2c transaction -- the i2c_access will prepare the transaction @@ -156,6 +159,9 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr, dev_dbg(&sch_adapter.dev, "SMBus busy (%02x)\n", temp); return -EAGAIN; } + dev_dbg(&sch_adapter.dev, "access speed: %d KHz\n", smbus_speed); + outb((backbone_speed / 4) / smbus_speed, SMBHSTCLK); + dev_dbg(&sch_adapter.dev, "access size: %d %s\n", size, (read_write)?"READ":"WRITE"); switch (size) { @@ -323,3 +329,5 @@ MODULE_LICENSE("GPL"); module_init(i2c_sch_init); module_exit(i2c_sch_exit); MODULE_ALIAS("platform:isch_smbus"); +module_param(smbus_speed, int, (S_IRUSR | S_IWUSR)); +module_param(backbone_speed, int, (S_IRUSR | S_IWUSR)); -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
