On a functioning FSI link there is not need to retry a write when doing
a scom in the driver.
Allow the higher layers (eg. userspace) to attempt a retry if they want,
or to accept that the address they are talking to is not accessible.
By removing the retries we can separate the error handling from retry
logic. In particular -EBUSY was used to force the get/put scom logic to
retry.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210527070109.225198-1-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
The error bits in the FSI2PIB status are only cleared by a reset. So
the driver needs to perform a reset after seeing any of the FSI2PIB
errors, otherwise subsequent operations will also look like failures.
Fixes: 6b293258cd ("fsi: scom: Major overhaul")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210329151344.14246-1-eajames@linux.ibm.com
Signed-off-by: Joel Stanley <joel@jms.id.au>
Currently the cfam_read and cfam_write functions return the provided
number of bytes given in the count parameter and not the error return
code in variable rc, hence all failures of read/writes are being
silently ignored. Fix this by returning the error code in rc.
Addresses-Coverity: ("Unused value")
Fixes: d1dcd67825 ("fsi: Add cfam char devices")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Jeremy Kerr <jk@ozlabs.org>
Link: https://lore.kernel.org/r/20210603122812.83587-1-colin.king@canonical.com
Signed-off-by: Joel Stanley <joel@jms.id.au>
This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Link: https://lore.kernel.org/r/1620896249-52769-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Joel Stanley <joel@jms.id.au>
- Driver for SB-TSI sensors
- Add support for P10 to fsi/occ
- Driver for LTC2992
- Driver for Delta power supplies Q54SJ108A2
- Support for NCT6687D added to nct6883 driver
- Support for Intel-based Xserves added to applesmc driver
- Driver for Maxim MAX127
- Support for AMD family 19h model 01h added to amd_energy driver
- Driver to support Corsair PSU
- Driver for STMicroelectronics PM6764 Voltage Regulator
- Various minor bug fixes and improvements
-----BEGIN PGP SIGNATURE-----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=YomY
-----END PGP SIGNATURE-----
Merge tag 'hwmon-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon updates from Guenter Roeck:
"New drivers:
- SB-TSI sensors
- Lineat Technology LTC2992
- Delta power supplies Q54SJ108A2
- Maxim MAX127
- Corsair PSU
- STMicroelectronics PM6764 Voltage Regulator
New chip support:
- P10 added to fsi/occ driver
- NCT6687D added to nct6883 driver
- Intel-based Xserves added to applesmc driver
- AMD family 19h model 01h added to amd_energy driver
And various minor bug fixes and improvements"
* tag 'hwmon-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: (41 commits)
dt-bindings: (hwmon/sbtsi_temp) Add SB-TSI hwmon driver bindings
hwmon: (sbtsi) Add documentation
hwmon: (sbtsi) Add basic support for SB-TSI sensors
hwmon: (iio_hwmon) Drop bogus __refdata annotation
hwmon: (xgene) Drop bogus __refdata annotation
dt-bindings: hwmon: convert AD ADM1275 bindings to dt-schema
hwmon: (occ) Add new temperature sensor type
fsi: occ: Add support for P10
dt-bindings: fsi: Add P10 OCC device documentation
dt-bindings: hwmon: convert TI ADS7828 bindings to dt-schema
dt-bindings: hwmon: convert AD AD741x bindings to dt-schema
dt-bindings: hwmon: convert TI INA2xx bindings to dt-schema
hwmon: (ltc2992) Fix less than zero comparisons with an unsigned integer
hwmon: (pmbus/q54sj108a2) Correct title underline length
dt-bindings: hwmon: Add documentation for ltc2992
hwmon: (ltc2992) Add support for GPIOs.
hwmon: (ltc2992) Add support
hwmon: (pmbus) Driver for Delta power supplies Q54SJ108A2
hwmon: Add driver for STMicroelectronics PM6764 Voltage Regulator
hwmon: (nct6683) Support NCT6687D.
...
The P10 OCC has a different SRAM address for the command and response
buffers. In addition, the SBE commands to access the SRAM have changed
format. Add versioning to the driver to handle these differences.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201120010315.190737-3-joel@jms.id.au
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
There is nothing to prevent multiple commands being executed
simultaneously. Add a mutex to prevent this.
Fixes: 606397d67f ("fsi: Add ast2600 master driver")
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201120004929.185239-1-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Systems have a line for restting the remote CFAM. This is not part of
the FSI master, but is associated with it, so it makes sense to include
it in the master driver.
This exposes a sysfs interface to reset the cfam, abstracting away the
direction and polarity of the GPIO, as well as the timing of the reset
pulse. Userspace will be blocked until the reset pulse is finished.
The reset is hard coded to be in the range of (900, 1000) us. It was
observed with a scope to regularly be just over 1ms.
If the device tree property is not preset the driver will silently
continue.
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20200728025527.174503-6-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
For testing and hardware debugging a user may wish to override the
divisor at runtime. By setting fsi_master_aspeed.bus_div=N, the divisor
will be set to N, if 0 < N <= 0x3ff.
This is a module parameter and not a device tree option as it will only
need to be set when testing or debugging.
Reviewed-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20200728025527.174503-5-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
Testing of Tacoma has shown that the ASPEED master can be run at maximum
speed.
The exception is when wired externally with a cable, in which case we
use a divisor of two to ensure reliable operation.
Reviewed-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20200728025527.174503-4-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
Some FSI capable systems have internal FSI signals, and some have
external cabled FSI. Software can detect which machine this is by
reading a jumper GPIO, and also control which pins the signals are
routed to through a mux GPIO.
This attempts to find the GPIOs at probe time. If they are not present
in the device tree the driver will not error and continue as before.
The mux GPIO is owned by the FSI driver to ensure it is not modified at
runtime. The routing jumper obtained as non-exclusive to allow other
software to inspect it's state.
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20200728025527.174503-3-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
The only usage of scom_ids is to assign its address to the id_table
field in the fsi_driver struct, which is a const pointer, so make it
const to allow the compiler to put it in read-only memory
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
The only usage of sbefifo_ids is to assign its address to the id_table
field in the fsi_driver struct, which is a const pointer, so make it
const to allow the compiler to put it in read-only memory
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
The only usage of hub_master_ids is to assign its address to the
id_table field in the fsi_driver struct, which is a const pointer, so
make it const to allow the compiler to put it in read-only memory.
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Both the Aspeed and hub masters read back the link enable register
after enabling the link, but this is unnecessary, so remove it.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
The driver ought to claim local bus ownership of the slave it's
communicating with.
This is for multi-master setups. The slave (in theory) will deny access
to masters who try to access the CFAM address space but who don't "own"
the bus.
As driver doesn't seem to perform any other teardown there is no need to
"un-claim" ownership at teardown. Also I'm not aware of any multi-master
setup using this driver so it shouldn't actually matter. Also, the
hardware doesn't seem to enforce this despite being required in the
specification...
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
In the case that links don't have slaves or fail to be accessed, the
master should disable the link during the scan since it won't be using
the slave.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Add the ability to disable a link with a boolean parameter to the
link_enable function. This is necessary so that the master can disable
links that it isn't using; for example, links to slaves that fail
initialization.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
In case of error, the function platform_device_register_full()
returns ERR_PTR() and never returns NULL. The NULL test in the
return value check should be replaced with IS_ERR().
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Joel Stanley <joel@jms.id.au>
In order to access more than the second hub link, 23-bit addressing is
required. The core provides the highest two bits of address as the slave
ID to the master.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
There is a spelling mistake in a dev_err error message. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.
This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.
There are a variety of indentation styles found.
a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'
In order to convert all of them to 1 tab + 'help', I ran the
following commend:
$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently CONFIG_FSI_MASTER_ASPEED=y implicitly depends on
CONFIG_HAS_IOMEM=y; consequently, on architectures without IOMEM we get
the following build error:
ld: drivers/fsi/fsi-master-aspeed.o: in function `fsi_master_aspeed_probe':
drivers/fsi/fsi-master-aspeed.c:436: undefined reference to `devm_ioremap_resource'
Fix the build error by adding the unspecified dependency.
Fixes: 606397d67f ("fsi: Add ast2600 master driver")
Cc: stable@vger.kernel.org
Reported-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200131034832.294268-1-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The data byte order selection registers in the APB2OPB primarily expose some
internal plumbing necessary to get correct write accesses onto the OPB.
OPB write cycles require "data mirroring" across the 32-bit data bus to
support variable data width slaves that don't implement "byte enables".
For slaves that do implement byte enables the master can signal which
bytes on the data bus the slave should consider valid.
The data mirroring behaviour is specified by the following table:
+-----------------+----------+-----------------------------------+
| | | 32-bit Data Bus |
+---------+-------+----------+---------+---------+-------+-------+
| | | | | | | |
| ABus | Mn_BE | Request | Dbus | Dbus | Dbus | Dbus |
| (30:31) | (0:3) | Transfer | 0:7 | 8:15 | 16:23 | 24:31 |
| | | Size | byte0 | byte1 | byte2 | byte3 |
+---------+-------+----------+---------+---------+-------+-------+
| 00 | 1111 | fullword | byte0 | byte1 | byte2 | byte3 |
+---------+-------+----------+---------+---------+-------+-------+
| 00 | 1110 | halfword | byte0 | byte1 | byte2 | |
+---------+-------+----------+---------+---------+-------+-------+
| 01 | 0111 | byte | _byte1_ | byte1 | byte2 | byte3 |
+---------+-------+----------+---------+---------+-------+-------+
| 00 | 1100 | halfword | byte0 | byte1 | | |
+---------+-------+----------+---------+---------+-------+-------+
| 01 | 0110 | byte | _byte1_ | byte1 | byte2 | |
+---------+-------+----------+---------+---------+-------+-------+
| 10 | 0011 | halfword | _byte2_ | _byte3_ | byte2 | byte3 |
+---------+-------+----------+---------+---------+-------+-------+
| 00 | 1000 | byte | byte0 | | | |
+---------+-------+----------+---------+---------+-------+-------+
| 01 | 0100 | byte | _byte1_ | byte1 | | |
+---------+-------+----------+---------+---------+-------+-------+
| 10 | 0010 | byte | _byte2_ | | byte2 | |
+---------+-------+----------+---------+---------+-------+-------+
| 11 | 0001 | byte | _byte3_ | _byte3_ | | byte3 |
+---------+-------+----------+---------+---------+-------+-------+
Mirrored data values are highlighted by underscores in the Dbus columns.
The values in the ABus and Request Transfer Size columns correspond to
values in the field names listed in the write data order select register
descriptions.
Similar configuration registers are exposed for reads which enables the
secondary purpose of configuring hardware endian conversions. It appears the
data bus byte order is switched around in hardware so set the registers such
that we can access the correct values for all widths. The values were
determined by experimentation on hardware against fixed CFAM register
values to configure the read data order, then in combination with the
table above and the register layout documentation in the AST2600
datasheet performing write/read cycles to configure the write data order
registers.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-12-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These trace points help with debugging the FSI master. They show the low
level reads, writes and error states of the master.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-11-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ast2600 BMC has a pair of FSI masters in it, behind an AHB to OPB
bridge.
The master driver supports reads and writes of full words, half word and
byte accesses to remote CFAMs. It can perform very basic error recovery
through resetting of the FSI port when an error is detected, and the
issuing of breaks and terms.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Alistair Popple <alistair@popple.id.au>
--
v2:
- remove debugging
- squash in fixes
Link: https://lore.kernel.org/r/20191108051945.7109-10-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The FSI master registers are common to the hub and AST2600 master (and
the FSP2, if someone was to upstream a driver for that).
Add defines to the fsi-master.h header, and introduce headings to
delineate the existing low level details.
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-8-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are no users outside of this file.
Fixes: 0604d53d4da8 ("fsi: Add fsi-master class")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-7-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subtracting the offset delta from four-byte alignment lead to wrapping
of the requested length where `count` is less than `off`. Generalise the
length handling to enable and optimise aligned access sizes for all
offset and size combinations. The new formula produces the following
results for given offset and count values:
offset count | length
--------------+-------
0 1 | 1
0 2 | 2
0 3 | 2
0 4 | 4
0 5 | 4
1 1 | 1
1 2 | 1
1 3 | 1
1 4 | 1
1 5 | 1
2 1 | 1
2 2 | 2
2 3 | 2
2 4 | 2
2 5 | 2
3 1 | 1
3 2 | 1
3 3 | 1
3 4 | 1
3 5 | 1
We might need something like this for the cfam chardevs as well, for
example we don't currently implement any alignment restrictions /
handling in the hardware master driver.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-6-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Populate fsi_master_class->dev_attrs with the existing attribute
definitions, so we don't need to explicitly register.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-3-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This change adds a device class for FSI masters, allowing access under
/sys/class/fsi-master/, and easier udev rules.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-2-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The scom driver currently fails out of operations if certain system
errors are flagged in the status register; system checkstop, special
attention, or recoverable error. These errors won't impact the ability
of the scom engine to perform operations, so the driver should continue
under these conditions.
Also, don't do a PIB reset for these conditions, since it won't help.
Fixes: 6b293258cd ("fsi: scom: Major overhaul")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20190827041249.13381-1-jk@ozlabs.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SBE fifo operations should be allowed while the SBE is in any of the
"IPL" states. Operations should succeed in this state.
Fixes: 9f4a8a2d7f fsi/sbefifo: Add driver for the SBE FIFO
Reviewed-by: Joel Stanley <joel@jms.id.au>
Tested-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/1561575415-3282-1-git-send-email-eajames@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Add MAINTAINERS entry. There is now a git tree and a mailing
list/patchwork for collecting FSI patches
- Bug fix for error driver registration error paths
- Correction for the OCC hwmon driver to meet the spec
-----BEGIN PGP SIGNATURE-----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=3yOz
-----END PGP SIGNATURE-----
Merge tag 'fsi-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/joel/fsi into char-misc-next
Joel writes:
FSI changes for 5.3
- Add MAINTAINERS entry. There is now a git tree and a mailing
list/patchwork for collecting FSI patches
- Bug fix for error driver registration error paths
- Correction for the OCC hwmon driver to meet the spec
* tag 'fsi-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/joel/fsi:
fsi/core: Fix error paths on CFAM init
OCC: FSI and hwmon: Add sequence numbering
MAINTAINERS: Add FSI subsystem
Change d1dcd67825 re-worked the struct fsi_slave initialisation in
fsi_slave_init, but introduced a few inconsitencies: the slave->dev is
now registered through cdev_device_add, but we may kfree() the device
out from underneath the cdev registration. We may also leave an IDA
allocated.
This change fixes the error paths, so that we kfree() only before the
device is registered with the core code. We also move the smode write to
before we start creating proper devices, as it's the most likely to
fail. We also remove the IDA-allocated minor on error, and properly
clean up the of_node.
Fixes: d1dcd67825 ("fsi: Add cfam char devices")
Reported-by: Lei YU <mine260309@gmail.com>
Tested-by: John Wang <wangzqbj@inspur.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Sequence numbering of the commands submitted to the OCC is required by
the OCC interface specification. Add sequence numbering and check for
the correct sequence number on the response.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Lei YU <mine260309@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
This patch corrects the SPDX License Identifier style
in header file related to Drivers for FRU Support Interface.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)
Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of mergchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 2 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081202.997941624@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 655 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The OCC is a device embedded on a POWER processor that collects and
aggregates sensor data from the processor and system. The OCC can
provide the raw sensor data as well as perform thermal and power
management on the system.
This driver provides an atomic communications channel between a service
processor (e.g. a BMC) and the OCC. The driver is dependent on the FSI
SBEFIFO driver to get hardware access through the SBE to the OCC SRAM.
Commands are issued to the SBE to send or fetch data to the SRAM.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Remove linux/cdev.h which is included more than once
Signed-off-by: Brajeswar Ghosh <brajeswar.linux@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In randconfig builds without CONFIG_GENERIC_ALLOCATOR, this driver
fails to link:
ERROR: "gen_pool_alloc_algo" [drivers/fsi/fsi-master-ast-cf.ko] undefined!
ERROR: "gen_pool_fixed_alloc" [drivers/fsi/fsi-master-ast-cf.ko] undefined!
ERROR: "of_gen_pool_get" [drivers/fsi/fsi-master-ast-cf.ko] undefined!
ERROR: "gen_pool_free" [drivers/fsi/fsi-master-ast-cf.ko] undefined!
Select the dependency as all other users do.
Fixes: 6a794a27da ("fsi: master-ast-cf: Add new FSI master using Aspeed ColdFire")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.
Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements. This makes it easier to add further
iterator types. Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.
Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself. Only the direction is required.
Signed-off-by: David Howells <dhowells@redhat.com>
Otherwise cronus putmem fails istep and BML fails to upload skiboot
To do that, we still use our one-page command buffer for small commands
for speed, and for anything bigger, with a limit of 1MB plus a page,
we vmalloc a temporary buffer.
The limit was chosen because Cronus will break up any data transfer
into 1M chunks (the extra page is for the command header).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
The chardev conversion forgot to copy the fsi_dev,
silly mistake, compounded by a testing mistake on
my side, this specific driver wasn't being tested
properly.
Fixes: d8f4587655 "fsi: scom: Convert to use the new chardev"
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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 aims to deprecate the "raw" sysfs file used for directly
accessing the CFAM and instead use a char device like the
other sub drivers.
Since it reworks the slave creation code and adds a cfam device
type, we also use the opportunity to convert the attributes
to attribute groups and add a couple more.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This converts FSI scom to use the new fsi-core controlled
chardev allocator and use a real cdev instead of a miscdev.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This converts FSI sbefifo to use the new fsi-core controlled
chardev allocator and use a real cdev instead of a miscdev.
One side effect is to fix the object lifetime by removing
the use of devm_kzalloc() for something that contains kobjects,
and using proper reference counting.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The various FSI devices (sbefifo, occ, scom, more to come)
currently use misc devices.
This is problematic as the minor device space for misc is
limited and there can be a lot of them. Also it limits our
ability to move them to a dedicated /dev/fsi directory or
to be smart about device naming and numbering.
It also means we have IDAs on every single of these drivers
This creates a common fsi "device_type" for the optional
/dev/fsi grouping and a dev_t allocator for all FSI devices.
"Legacy" devices get to use a backward compatible numbering
scheme (as long as chip id <16 and there's only one copy
of a given unit type per chip).
A single major number and a single IDA are shared for all
FSI devices.
This doesn't convert the FSI device drivers to use the new
scheme yet, they will be converted individually.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
s390 defines a global dump_trace() symbol. Rename ours to
dump_ucode_trace() to avoid a collision in build tests.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In case memory resources for *fw* were allocated, release them
before return.
Addresses-Coverity-ID: 1472044 ("Resource leak")
Fixes: 6a794a27da ("fsi: master-ast-cf: Add new FSI master using Aspeed ColdFire")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Then reading the RTAG/RCRC "registers" from the coprocessor after
a command is complete, mask out the top bits, only keep the relevant
bits. Microcode v5 will leave garbage in those top bits as a
result of a performance optimization.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
Some of the exit path missed the unlock. Move the mutex to
an outer function to avoid the problem completely
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The Aspeed AST2x00 can contain a ColdFire v1 coprocessor which
is currently unused on OpenPower systems.
This adds an alternative to the fsi-master-gpio driver that
uses that coprocessor instead of bit banging from the ARM
core itself. The end result is about 4 times faster.
The firmware for the coprocessor and its source code can be
found at https://github.com/ozbenh/cf-fsi and is system specific.
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>
The embedded struct device needs a release function to be
able to successfully remove the driver.
We remove the devm_gpiod_put() as they are unnecessary
(the resources will be released automatically) and because
fsi_master_unregister() will cause the master structure to
be freed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
In the error path of fsi_master_register(), we currently
use device_unregister(). This will cause the last reference
to the structure to be dropped, thus freeing the enclosing
structure, which isn't what the callers want.
Use device_del() instead so that we return to the caller
with a refcount of 1. The caller can then assume that it
must use put_device() after a call to fsi_master_register()
regardless of whether the latter suceeded or failed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some definitions are generic to the FSI protocol or any
give master implementation. Rename them to remove the
"GPIO" prefix in preparation for moving them to a common
header.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
# Conflicts:
# drivers/fsi/fsi-master-gpio.c
This adds a few more tracepoints that have proven useful when
debugging issues with the FSI bus.
This also makes echo_delay() use clock_zeros() instead of
open-code it in order to share the tracepoint.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
What the driver called "FSI_GPIO_PRIME_SLAVE_CLOCKS" is what
the FSI spec calls tSendDelay and should be 16 clocks by
default.
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>
---
Move fsi_slave_set_smode() and its helpers to before it's
first user and remove the corresponding forward declaration.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
"dev" is dereferences before it's checked.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The driver calls of_platform_device_create() which is only available
if OF_ADDRESS is enabled. When building sparc64 images, this results
in
ERROR: "of_platform_device_create" [drivers/fsi/fsi-sbefifo.ko] undefined!
Fixes: 9f4a8a2d7f ("fsi/sbefifo: Add driver for the SBE FIFO")
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There was no unlock of the FFDC mutex.
Fixes: 9f4a8a2d7f ("fsi/sbefifo: Add driver for the SBE FIFO")
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This was too hard to split ... this adds a number of features
to the SCOM user interface:
- Support for indirect SCOMs
- read()/write() interface now handle errors and retries
- New ioctl() "raw" interface for use by debuggers
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Add a few more register and bit definitions, also define and use
SCOM_READ_CMD (which is 0 but it makes the code clearer)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
Use the proper annotated type __be32 and fixup the
accessor used for get_scom()
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
Otherwise, multiple clients can open the driver and attempt
to access the PIB at the same time, thus clobbering each other
in the process.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
fsi-master-hub.c:128:13: warning: incorrect type in assignment (different base types)
fsi-master-hub.c:128:13: expected unsigned int [unsigned] [usertype] cmd
fsi-master-hub.c:128:13: got restricted __be32 [usertype] <noident>
fsi-master-hub.c:208:13: warning: incorrect type in assignment (different base types)
fsi-master-hub.c:208:13: expected restricted __be32 [addressable] [assigned] [usertype] reg
fsi-master-hub.c:208:13: got int
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
fsi-sbefifo.c:547:58: warning: incorrect type in argument 2 (different base types)
fsi-sbefifo.c:547:58: expected restricted __be32 [usertype] *word
fsi-sbefifo.c:547:58: got unsigned int *<noident>
fsi-sbefifo.c:635:16: warning: incorrect type in assignment (different base types)
fsi-sbefifo.c:635:16: expected unsigned int [unsigned] <noident>
fsi-sbefifo.c:635:16: got restricted __be32 [usertype] <noident>
fsi-sbefifo.c:636:16: warning: incorrect type in assignment (different base types)
fsi-sbefifo.c:636:16: expected unsigned int [unsigned] <noident>
fsi-sbefifo.c:636:16: got restricted __be32 [usertype] <noident>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This driver provides an in-kernel and a user API for accessing
the command FIFO of the SBE (Self Boot Engine) of the POWER9
processor, via the FSI bus.
It provides an in-kernel interface to submit command and receive
responses, along with a helper to locate and analyse the response
status block. It's a simple synchronous submit() type API.
The user interface uses the write/read interface that an earlier
version of this driver already provided, however it has some
specific limitations in order to keep the driver simple and
avoid using up a lot of kernel memory:
- The user should perform a single write() with the command and
a single read() to get the response (with a buffer big enough
to hold the entire response).
- On a write() the command is simply "stored" into a kernel buffer,
it is submitted as one operation on the subsequent read(). This
allows to have the code write directly from the FIFO into the user
buffer and avoid hogging the SBE between the write() and read()
syscall as it's critical that the SBE be freed asap to respond
to the host. An extra write() will simply replace the previously
written command.
- A write of a single 4 bytes containing the value 0x52534554
in big endian will trigger a reset request. No read is necessary,
the write() call will return when the reset has been acknowledged
or times out.
- The command is limited to 4K bytes.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
---
The PIB reset causes problems for the running P9 chip. The reset
shouldn't be performed by this driver.
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
We currently use a spinlock (bit_lock) around operations that clock bits
out of the FSI bus, and a mutex to protect against simultaneous access
to the master.
This means that bit_lock isn't needed for mutual exlusion, only to
prevent timing issues when clocking bits out.
To reflect this, this change converts bit_lock to just the
local_irq_save/restore operation.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Remove calls to the empty and useless fsi_master_gpio_error()
function, and report CRC errors as "FSI_ERR_NO_SLAVE" when
reading an all 1's response.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
The FSI protocol defines two modes of recovery from CRC errors,
this implements both:
- If the device returns an ECRC (it detected a CRC error in the
command), then we simply issue the command again.
- If the master detects a CRC error in the response, we send
an E_POLL command which requests a resend of the response
without actually re-executing the command (which could otherwise
have unwanted side effects such as dequeuing a FIFO twice).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
---
Note: This was actually tested by removing some of my fixes, thus
causing us to hit occasional CRC errors during high LPC activity.
FSI CFAMs support shorter commands that use a relative (or same) address
as the last. This change introduces a last_addr to the master state, and
uses it for subsequent reads/writes, and performs relative addressing
when a subsequent read/write is in range.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
For implementing relative addressing mode, we'll need to build a command
that is coherent with CFAM state. To do that, include the
build_command_* functions in the locked section of read/write/term.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Most SoC GPIO implementations, including the Aspeed one, have
synchronizers on the GPIO inputs. This means that the value
read from a GPIO is a couple of clocks old, from whatever clock
source feeds those synchronizers.
In practice, this means that in no-delay mode, we are using a
value that can potentially be a bit too old and too close to
the clock edge establishing the data on the other side of the link.
The voltage converters we use on some systems make this worse
and sensitive to things like voltage fluctuations etc... This is,
we believe, the cause of occasional CRC errors encountered during
heavy activity on the LPC bus.
This is fixed by introducing a dummy GPIO read before the actual
data read. It slows down SBEFIFO by about 15% (less than any delay
primitive) and the end result is so far solid.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
FSI_GPIO_DPOLL_CLOCKS is the number of clocks before sending
a DPOLL command after receiving a BUSY status. It should be
at least tSendDelay (16 clocks).
According to comments in the code, it needs to also be at least
21 clocks due to HW issues.
It's currently 100 clocks which impacts performances negatively
in some cases. Reduces it in half to 50 clocks which seems to
still be solid.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
FSI_GPIO_PRIME_SLAVE_CLOCKS is the number of clocks if the
"idle" phase between the end of a response and the beginning
of the next one. It corresponds to tSendDelay in the FSI
specification.
The default value in the slave is 16 clocks. 100 is way overkill
and significantly reduces the driver performance.
This changes it to 20 (which gives the HW a bit of margin still
just in case).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
This adds support for an optional device-tree property that
makes the driver skip all the delays around clocking the
GPIOs and set it in the device-tree of common POWER9 based
OpenPower platforms.
This useful on chips like the AST2500 where the GPIO block is
running at a fairly low clock frequency (25Mhz typically). In
this case, the delays are unnecessary and due to the low
precision of the timers, actually quite harmful in terms of
performance.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
We currently sample the input data right after we toggle the
clock low, then high. The slave establishes the data on the
rising edge, so this is not ideal. We should sample it on
the low phase instead.
This currently works because we have an extra delay, but subsequent
patches will remove it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Reduce time spent with interrupts disabled by limiting the critical
sections to bitbanging FSI symbols. We only need to ensure exclusive use
of the bus for an entire transfer, not that the transfer be performed in
atomic context.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
An observation from trace output of the existing FSI tracepoints was
that the remote device was sometimes reporting as busy. Add a new
tracepoint reporting the busy count in order to get a better grip on how
often this is the case.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Eddie James <eajames@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
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>
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>
