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| author | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2012-07-24 14:13:59 +0200 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2012-07-24 14:13:59 +0200 |
| commit | 72fc2c7f78b0c365454e60ad33b0e74aea43e3ab (patch) | |
| tree | b4416754f881f49b0e4cdb3585ed1f598c5a6c56 /drivers/i2c/i2c-core.c | |
| parent | d47726c52122d64253ae56e0fafdb7d0b954e97c (diff) | |
| download | lwn-72fc2c7f78b0c365454e60ad33b0e74aea43e3ab.tar.gz lwn-72fc2c7f78b0c365454e60ad33b0e74aea43e3ab.zip | |
i2c: Fall back to emulated SMBus if the operation isn't supported natively
Adapter drivers might support only a subset of the SMBus operations
natively. Those drivers currently have to manually emulate unsupported
operations using I2C.
Make the i2c_smbus_xfer() function fall back to
i2c_smbus_xfer_emulated() when the adapter's .smbus_xfer() operation
returns -EOPNOTSUPP, like it already does when the .smbus_xfer()
operation isn't available at all.
[JD: Minor optimization.]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 361978a8485a..26488aa893d5 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -2140,11 +2140,17 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, break; } i2c_unlock_adapter(adapter); - } else - res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, - command, protocol, data); - return res; + if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) + return res; + /* + * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't + * implement native support for the SMBus operation. + */ + } + + return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, + command, protocol, data); } EXPORT_SYMBOL(i2c_smbus_xfer); |