The bus scanning process isn't terribly good at parallel attempts
at rescanning the same bus. Let's have a per-master mutex protecting
the scanning process.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This moves the definitions for various protocol details
(message & response codes, delays etc...) out of
fsi-master-gpio.c to fsi-master.h in order to share them
with other master implementations.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Those values control the amount of "dummy" clocks between commands and
between a command and its response.
This adds a way to configure them from sysfs (to be later extended to
defaults in the device-tree). The default remains 16 (the HW default).
This is only supported if the backend supports the new link_config()
callback to configure the generation of those delays.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
---
Once we call fsi_master_unregister, the core will put_device,
potentially freeing the hub master. This change adds a comment
explaining the lifetime of an allocated fsi_master.
We then add a reference from the driver to the hub master, so it stays
around until we've finished ->remove().
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We'll want non-core fsi code to trigger a rescan, so introduce a
non-static fsi_master_rescan() function. Use this for the existing
unscan/scan behaviour too.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Christopher Bostic <clbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For slaves that are behind a software-clocked master, we want FSI CFAMs
to run asynchronously to the FSI clock, so set up our slaves to be in
async mode.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a `struct fsi_master` to represent a FSI master controller.
FSI master drivers register one of these structs to provide
device-specific of the standard operations: read/write/term/break and
link control.
Includes changes from Edward A. James <eajames@us.ibm.com> & Jeremy Kerr
<jk@ozlabs.org>.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Benjamin Herrenschmidt