Commit Graph

3 Commits

Author SHA1 Message Date
Wei Yongjun
1da8726700 i2c: mux: mlxcpld: remove unused including <linux/version.h>
Remove including <linux/version.h> that don't need it.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-02-09 17:29:21 +01:00
Peter Rosin
649ac63a9a i2c: mux: mlxcpld: fix i2c mux selection caching
smbus functions return -ve on error, 0 on success.  However,
__i2c_transfer() have a different return signature - -ve on error, or
number of buffers transferred (which may be zero or greater).

The upshot of this is that the sense of the test is reversed when using
the mux on a bus supporting the master_xfer method: we cache the value
and never retry if we fail to transfer any buffers, but if we succeed,
we clear the cached value.

Fix this by making mlxcpld_mux_reg_write() return a -ve error code for
all failure cases, just as was done in commit 7f638c1cb0 ("i2c: mux:
pca954x: fix i2c mux selection caching").

This also aligns the implementations of these two muxes in this area.

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-12-18 08:54:38 +01:00
Vadim Pasternak
c02b7bf532 i2c: mux: mellanox: add driver
This driver allows I2C routing controlled through CPLD select registers on
a wide range of Mellanox systems (CPLD Lattice device).
MUX selection is provided by digital and analog HW. Analog part is not
under SW control.
Digital part is under CPLD control (channel selection/de-selection).

Connectivity schema.
.---.             .-------------.
| l |             |             |-- i2cx1 -- i2cx8
| i |-- i2cn --+--| mlxcpld mux |
| n |          |  |             |-- i2cy1 -- i2cy8
| u |          |  '-------------'
| x |          |         |
'---'          '---------'

i2c-mux-mlxpcld does not necessarily require i2c-mlxcpld. It can be used
along with another bus driver, and still control i2c routing through CPLD
mux selection, in case the system is equipped with CPLD capable of mux
selection control.

The Kconfig currently controlling compilation of this code is:
drivers/i2c/muxes/Kconfig:config I2C_MUX_MLXCPLD

Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-17 23:19:00 +01:00