Commit graph

37 commits

Author SHA1 Message Date
Christopher Bostic
f3aa2c6f98 fsi: core: Add check for master property no-scan-on-init
Prior to scanning a master check if the optional property
no-scan-on-init is present.  If it is then avoid scanning.  This is
necessary in cases where a master scan could interfere with another
FSI master on the same bus.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:01 +01:00
Jeremy Kerr
e0c24bddf0 fsi: master: Clarify master lifetimes & fix use-after-free in hub master
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>
2018-03-14 19:11:01 +01:00
Christopher Bostic
638bd9ac84 fsi: core: Reduce console output during normal scan
To reduce amount of console output during boot / power up make
all normal path scan related messages debug type.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:01 +01:00
Jeremy Kerr
f6a2f8eb73 fsi: Match fsi slaves and engines to available dt nodes
This change populates device tree nodes for scanned FSI slaves and
engines. If the master populates ->of_node of the FSI master device,
we'll look for matching slaves, and under those slaves we'll look for
matching engines.

This means that FSI drivers will have their ->of_node pointer populated
if there's a corresponding DT node, which they can use for further
device discover.

Presence of device tree nodes is optional, and only required for
fsi device drivers that need extra properties, or subordinate devices,
to be enumerated.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Eddie James
99f039e97b fsi: Fix one and two byte bus reads/writes
Address checker fixed to allow one and two byte reads/writes.
Address alignments for each size verified.

Signed-off-by: Edward James <eajames@us.ibm.com>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Jeremy Kerr
b8bd146d38 fsi: master-gpio: Add external mode
This change introduces an 'external mode' for GPIO-based FSI masters,
allowing the clock and data lines to be driven by an external source.
For example, external mode is selected by a user when an external debug
device is attached to the FSI pins.

To do this, we need to set specific states for the trans, mux and enable
GPIOs, and prevent access to clk & data from the FSI core code (by
returning EBUSY).

External mode is controlled by a sysfs attribute, so add the relevant
information to Documentation/ABI/

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-14 19:11:00 +01:00
Jeremy Kerr
29d9b92711 fsi: master-gpio: Add locking during break and link enable
Currently, we perform GPIO accesses in fsi_master_gpio_break and
fsi_master_link_enable, without holding cmd_lock. This change adds the
appropriate locking.

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>
2018-03-14 19:11:00 +01:00
Jeremy Kerr
15362d69c4 fsi: Add fsi_master_rescan()
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>
2018-03-14 19:11:00 +01:00
Vincent Legoll
baa8b941cb fsi: Make FSI a menuconfig to ease disabling it all
No need to get into the submenu to disable all FSI-related config entries

Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 18:41:12 +01:00
Colin Ian King
ed50a0890e drivers/fsi: make a couple of functions static
The functions fsi_slave_report_and_clear_errors and fsi_slave_handle_error
are local to the source and do not need to be in global scope, so make
them static.

Cleans up sparse warnings:
symbol 'fsi_slave_report_and_clear_errors' was not declared. Should it
be static?
symbol 'fsi_slave_handle_error' was not declared. Should it be static?

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-04 10:32:42 +02:00
Edward A. James
47a6623b2d drivers/fsi/scom: Remove reset before every putscom
Reset causes problems for operations requiring multiple scoms (e.g. i2c
over scom). Instead, reset scom engine during probe.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 17:15:16 +02:00
Bhumika Goyal
061c0958de drivers/fsi: add const to bin_attribute structures
Declare bin_attribute structures as const as they are only passed as an
argument to the function device_create_bin_file. This argument is of
type const, so declare the structure as const.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 17:15:16 +02:00
Arnd Bergmann
ceb8a12ff2 drivers/fsi: fix fsi_slave_mode prototype
gcc warns about the return type of this function:

drivers/fsi/fsi-core.c:535:8: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]

This removes the 'const' attribute, as suggested by the warning.

Fixes: 2b37c3e285 ("drivers/fsi: Set slave SMODE to init communication")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-17 16:13:54 +02:00
Joel Stanley
496f8931b6 fsi: core: register with postcore_initcall
When testing an i2c driver that is a fsi bus driver, I saw the following
oops:

 kernel BUG at drivers/base/driver.c:153!
 Internal error: Oops - BUG: 0 [#1] ARM

 [<8027cb1c>] (driver_register) from [<80344e88>] (fsi_driver_register+0x2c/0x38)
 [<80344e88>] (fsi_driver_register) from [<805f5ebc>] (fsi_i2c_driver_init+0x1c/0x24)
 [<805f5ebc>] (fsi_i2c_driver_init) from [<805d1f14>] (do_one_initcall+0xb4/0x170)
 [<805d1f14>] (do_one_initcall) from [<805d20f0>] (kernel_init_freeable+0x120/0x1dc)
 [<805d20f0>] (kernel_init_freeable) from [<8043f4a8>] (kernel_init+0x18/0x104)
 [<8043f4a8>] (kernel_init) from [<8000a5e8>] (ret_from_fork+0x14/0x2c)

This is because the fsi bus had not been registered. This fix registers the bus
with postcore_initcall instead, to ensure it is registered earlier on.

When the fsi core is used as a module this should not be a problem as the fsi
driver will depend on the fsi bus type symbol, and will therefore load the core
before the driver.

Fixes: 0508ad1fff ("drivers/fsi: Add empty fsi bus definitions")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-17 16:13:54 +02:00
Christopher Bostic
acb7e8f744 drivers/fsi: Add module license to core driver
Add missing MODULE_LICENSE("GPL") to the core FSI driver.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Jeremy Kerr
4af889b0ff drivers/fsi: Use asynchronous slave mode
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>
2017-06-09 11:52:09 +02:00
Christopher Bostic
7f9e8f7670 drivers/fsi: Add hub master support
Add an engine driver to expose a "hub" FSI master - which has a set of
control registers in the engine address space, and uses a chunk of the
slave address space for actual FSI communication.

Additional changes from Jeremy Kerr <jk@ozlabs.org>.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Christopher Bostic
680ca6dcf5 drivers/fsi: Add SCOM FSI client device driver
Create a simple SCOM engine device driver that reads and writes
its control registers via an FSI bus.

Includes changes from Edward A. James <eajames@us.ibm.com>.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:09 +02:00
Jeremy Kerr
1247cf7ab8 drivers/fsi/gpio: Add tracepoints for GPIO master
Trace low level input/output GPIO operations.

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>
2017-06-09 11:52:09 +02:00
Christopher Bostic
ac0385d9f6 drivers/fsi: Add GPIO based FSI master
Implement a FSI master using GPIO.  Will generate FSI protocol for
read and write commands to particular addresses.  Sends master command
and waits for and decodes a slave response.

Includes changes from Edward A. James <eajames@us.ibm.com> and Jeremy
Kerr <jk@ozlabs.org>.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-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>
2017-06-09 11:52:09 +02:00
Jeremy Kerr
1fa847d74a drivers/fsi: Add error handling for slave
This change implements error handling in the FSI core, by cleaining up
and retrying failed operations, using the SISC, TERM and BREAK
facilities.

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>
2017-06-09 11:52:09 +02:00
Jeremy Kerr
66433b05a3 drivers/fsi: Add tracepoints for low-level operations
Trace low level read and write FSI bus operations.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr
da36cadf89 drivers/fsi: expose direct-access slave API
Allow drivers to access the slave address ranges.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr
125739cbc1 drivers/fsi: Add sysfs files for FSI master & slave accesses
This change adds a 'raw' file for reads & writes, and a 'term' file for
the TERM command, and a 'break' file for issuing a BREAK.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Christopher Bostic
356d8009a5 drivers/fsi: Add client driver register utilities
Add driver_register and driver_unregister wrappers for FSI.

Signed-off-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>
2017-06-09 11:52:08 +02:00
Christopher Bostic
cd0fdb5c07 drivers/fsi: Add master unscan
Allow a master to undo a previous scan.  Should a master scan a bus
twice it will need to ensure it doesn't double register any
previously detected device.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
----
v7 - Unscan when unregistering master
   - Remove leading '__'s from function names
   - Return fail state for sysfs rescan file
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:08 +02:00
Jeremy Kerr
4efe37f4c4 drivers/fsi: Add device read/write/peek API
This change introduces the fsi device API: simple read, write and peek
accessors for the devices' address spaces.

Includes contributions from Christopher Bostic
<cbostic@linux.vnet.ibm.com> and Edward A. James <eajames@us.ibm.com>.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-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>
2017-06-09 11:52:08 +02:00
Jeremy Kerr
f7ade2a603 drivers/fsi: scan slaves & register devices
Now that we have fsi_slave devices, scan each for endpoints, and
register them on the fsi bus.

Includes contributions from Christopher Bostic
<cbostic@linux.vnet.ibm.com>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-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>
2017-06-09 11:52:08 +02:00
Christopher Bostic
2b37c3e285 drivers/fsi: Set slave SMODE to init communication
Set CFAM to appropriate ID so that the controlling master can manage
link memory ranges.  Add slave engine register definitions.

Includes changes from Jeremy Kerr <jk@ozlabs.org>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-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>
2017-06-09 11:52:08 +02:00
Jeremy Kerr
2b545cd8e1 drivers/fsi: Implement slave initialisation
Implement fsi_slave_init: if we can read a chip ID, create fsi_slave
devices and register with the driver core.

Includes changes from Christopher Bostic <cbostic@linux.vnet.ibm.com>.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-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>
2017-06-09 11:52:08 +02:00
Christopher Bostic
2609528211 drivers/fsi: Set up links for slave communication
Enable each link and send a break command, and try to detect a slave by
reading from the SMODE register.

Signed-off-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>
2017-06-09 11:52:08 +02:00
Jeremy Kerr
014c2abc53 drivers/fsi: Add slave & master read/write APIs
Introduce functions to perform reads/writes on the slave address space;
these simply pass the request on the slave's master with the correct
link and slave ID.

We implement these on top of similar helpers for the master.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:52:07 +02:00
Jeremy Kerr
414c102631 drivers/fsi: Add empty master scan
When a new fsi master is added, we will need to scan its links, and
slaves attached to those links. This change introduces a little shell to
iterate the links, which we will populate with the actual slave scan in
a later change.

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>
2017-06-09 11:52:07 +02:00
Jeremy Kerr
faf0b116de drivers/fsi: Add slave definition
Add the initial fsi slave device, which is private to the core code.
This will be a child of the master, and parent to endpoint devices.

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>
2017-06-09 11:52:07 +02:00
Jeremy Kerr
09aecfab93 drivers/fsi: Add fsi master definition
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>
2017-06-09 11:52:07 +02:00
Jeremy Kerr
dd37eed7db drivers/fsi: add driver to device matches
Driver bind to devices based on the engine types & (optional) versions.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:19:48 +01:00
Jeremy Kerr
0508ad1fff drivers/fsi: Add empty fsi bus definitions
This change adds the initial (empty) fsi bus definition, and introduces
drivers/fsi/.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-10 15:19:48 +01:00