Watchdog: sp5100_tco: Enable Family 17h+ CPUs

The driver currently uses a CPU family match of 17h to determine
EFCH_PM_DECODEEN_WDT_TMREN register support. This family check will not
support future AMD CPUs and instead will require driver updates to add
support.

Remove the family 17h family check and add a check for SMBus PCI
revision ID 0x51 or greater. The MMIO access method has been available
since at least SMBus controllers using PCI revision 0x51. This revision
check will support family 17h and future AMD processors including EFCH
functionality without requiring driver changes.

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220202153525.1693378-5-terry.bowman@amd.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Watchdog: sp5100_tco: Add initialization using EFCH MMIO

cd6h/cd7h port I/O can be disabled on recent AMD hardware. Read
accesses to disabled cd6h/cd7h port I/O will return F's and written
data is dropped. It is recommended to replace the cd6h/cd7h
port I/O with MMIO.

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220202153525.1693378-4-terry.bowman@amd.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Watchdog: sp5100_tco: Refactor MMIO base address initialization

Combine MMIO base address and alternate base address detection. Combine
based on layout type. This will simplify the function by eliminating
a switch case.

Move existing request/release code into functions. This currently only
supports port I/O request/release. The move into a separate function
will make it ready for adding MMIO region support.

Co-developed-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220202153525.1693378-3-terry.bowman@amd.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: sp5100: Fix definition of EFCH_PM_DECODEEN3

EFCH_PM_DECODEEN3 is supposed to access DECODEEN register bits 24..31,
in other words the register at byte offset 3.

Cc: Jan Kiszka <jan.kiszka@siemens.com>
Fixes: 887d2ec51e34b ("watchdog: sp5100_tco: Add support for recent FCH versions")
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/20200910163109.235136-1-linux@roeck-us.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

watchdog: sp5100_tco: Add support for recent FCH versions

Starting with Family 16h Models 30h-3Fh and Family 15h Models 60h-6Fh,
watchdog address space decoding has changed. The cutover point is already
identified in the i2c-piix2 driver, so use the same mechanism.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: sp5100-tco: Abort if watchdog is disabled by hardware

If the watchdog control register indicates that the watchdog hardware
is disabled even after we tried to enable it, there is no point to
instantiate the driver.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: sp5100_tco: Use bit operations

Using bit operations makes it easier to improve the driver.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: sp5100_tco: Clean up function and variable names

Use more common function and variable names.

Use pdev instead of dev for platform device.
Use sp5100_tco_probe() instead of sp5100_tco_init() for the probe function.
Drop sp5100_tco_cleanup(); just move the code into sp5100_tco_remove().
Use sp5100_tco_init() instead of sp5100_tco_init_module() for the module
initialization function.
Use sp5100_tco_exit() instead of sp5100_tco_cleanup_module() for the module
exit function.
Use consistent defines for accessing the watchdog control register.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: sp5100_tco: Fix watchdog disable bit

According to all published information, the watchdog disable bit for SB800
compatible controllers is bit 1 of PM register 0x48, not bit 2. For the
most part that doesn't matter in practice, since the bit has to be cleared
to enable watchdog address decoding, which is the default setting, but it
still needs to be fixed.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: sp5100_tco: Always use SP5100_IO_PM_{INDEX_REG,DATA_REG}

SP5100_IO_PM_INDEX_REG and SB800_IO_PM_INDEX_REG are used inconsistently
and define the same value. Just use SP5100_IO_PM_INDEX_REG throughout.
Do the same for SP5100_IO_PM_DATA_REG and SB800_IO_PM_DATA_REG.
Use helper functions to access the indexed registers.

Cc: Zoltán Böszörményi <zboszor@pr.hu>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

watchdog: sp5100_tco: Set the AcpiMmioSel bitmask value to 1 instead of 2

The AcpiMmioSel bit is bit 1 in the AcpiMmioEn register, but the current
sp5100_tco driver is using bit 2.

See 2.3.3 Power Management (PM) Registers page 150 of the
AMD SB800-Series Southbridges Register Reference Guide [1].

AcpiMmioEn - RW – 8/16/32 bits - [PM_Reg: 24h]
Field Name Bits Default Description
AcpiMMioDecodeEn 0 0b Set to 1 to enable AcpiMMio space.
AcpiMMIoSel 1 0b Set AcpiMMio registers to be memory-mapped or IO-mapped space.
0: Memory-mapped space
1: I/O-mapped space

The sp5100_tco driver expects zero as a value of AcpiMmioSel (bit 1).

Fortunately, no problems were caused by this typo, because the default
value of the undocumented misused bit 2 seems to be zero.

However, the sp5100_tco driver should use the correct bitmask value.

[1] http://support.amd.com/us/Embedded_TechDocs/45482.pdf

Signed-off-by: Takahisa Tanaka <mc74hc00@gmail.com>
Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: stable <stable@vger.kernel.org>

watchdog: sp5100_tco: Add SB8x0 chipset support

The current sp5100_tco driver only supports SP5100/SB7x0 chipset, doesn't
support SB8x0 chipset, because current sp5100_tco driver doesn't know that the
offset address for watchdog timer was changed from SB8x0 chipset.

The offset address of SP5100 and SB7x0 chipsets are as follows, quote from the
AMD SB700/710/750 Register Reference Guide (Page 164) and the AMD SP5100
Register Reference Guide (Page 166).

WatchDogTimerControl 69h
WatchDogTimerBase0 6Ch
WatchDogTimerBase1 6Dh
WatchDogTimerBase2 6Eh
WatchDogTimerBase3 6Fh

In contrast, the offset address of SB8x0 chipset is as follows, quote from
AMD SB800-Series Southbridges Register Reference Guide (Page 147).

WatchDogTimerEn 48h
WatchDogTimerConfig 4Ch

So, In the case of SB8x0 chipset, sp5100_tco reads meaningless MMIO
address (for example, 0xbafe00) from wrong offset address, and the following
message is logged.

SP5100 TCO timer: mmio address 0xbafe00 already in use

With this patch, sp5100_tco driver supports SB8x0 chipset, and can avoid
iomem resource conflict. The processing of this patch is as follows.

Step 1) Attempt to get the watchdog base address from indirect I/O (0xCD6
and 0xCD7).
- Go to the step 7 if obtained address hasn't conflicted with other
resource. But, currently, the address (0xfec000f0) conflicts with the
IOAPIC MMIO address, and the following message is logged.

SP5100 TCO timer: mmio address 0xfec000f0 already in use

0xfec000f0 is recommended by AMD BIOS Developer's Guide. So, go to the
next step.

Step 2) Attempt to get the SBResource_MMIO base address from AcpiMmioEN (for
SB8x0, PM_Reg:24h) or SBResource_MMIO (SP5100/SB7x0, PCI_Reg:9Ch)
register.
- Go to the step 7 if these register has enabled by BIOS, and obtained
address hasn't conflicted with other resource.
- If above condition isn't true, go to the next step.

Step 3) Attempt to get the free MMIO address from allocate_resource().
- Go to the step 7 if these register has enabled by BIOS, and obtained
address hasn't conflicted with other resource.
- Driver initialization has failed if obtained address has conflicted
with other resource, and no 'force_addr' parameter is specified.

Step 4) Use the specified address If 'force_addr' parameter is specified.
- allocate_resource() function may fail, when the PCI bridge device occupies
iomem resource from 0xf0000000 to 0xffffffff. To handle such a case,
I added 'force_addr' parameter to sp5100_tco driver. With 'force_addr'
parameter, sp5100_tco driver directly can assign MMIO address for watchdog
timer from free iomem region. Note that It's dangerous to specify wrong
address in the 'force_addr' parameter.

Example of force_addr parameter use
# cat /proc/iomem
...snip...
fec00000-fec003ff : IOAPIC 0
<--- free MMIO region
fec10000-fec1001f : pnp 00:0b
fec20000-fec203ff : IOAPIC 1
...snip...
# cat /etc/modprobe.d/sp5100_tco.conf
options sp5100_tco force_addr=0xfec00800
# modprobe sp5100_tco
# cat /proc/iomem
...snip...
fec00000-fec003ff : IOAPIC 0
fec00800-fec00807 : SP5100 TCO <--- watchdog timer MMIO address
fec10000-fec1001f : pnp 00:0b
fec20000-fec203ff : IOAPIC 1
...snip...
#

- Driver initialization has failed if specified address has conflicted
with other resource.

Step 5) Disable the watchdog timer
- To rewrite the watchdog timer register of the chipset, absolutely
guarantee that the watchdog timer is disabled.

Step 6) Re-program the watchdog timer MMIO address to chipset.
- Re-program the obtained MMIO address in Step 3 or Step 4 to chipset via
indirect I/O (0xCD6 and 0xCD7).

Step 7) Enable and setup the watchdog timer

This patch has worked fine on my test environment (ASUS M4A89GTD-PRO/USB3 and
DL165G7). therefore I believe that it's no problem to re-program the MMIO
address for watchdog timer to chipset during disabled watchdog. However,
I'm not sure about it, because I don't know much about chipset programming.

So, any comments will be welcome.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43176
Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Tested-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Takahisa Tanaka <mc74hc00@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: Add support for sp5100 chipset TCO

This driver adds /dev/watchdog support for the AMD sp5100 aka SB7x0 chipsets.

It follows the same conventions found in other /dev/watchdog drivers.

Signed-off-by: Priyanka Gupta <priyankag@google.com>
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>