u-boot.git/drivers/timer/tsc_timer.c, branch v2020.01-rc5

common: Move get_ticks() function out of common.h

2019-12-02T23:23:13+00:00

This function belongs in time.h so move it over and add a comment.

Signed-off-by: Simon Glass 
Reviewed-by: Tom Rini

x86: timer: Use a separate flag for whether timer is inited

2019-11-02T23:20:27+00:00

At present the value of the timer base is used to determine whether the
timer has been set up or not. It is true that the timer is essentially
never exactly 0 when it is read. However 'time 0' may indicate the time
that the machine was reset so it is useful to be able to denote that.

Update the code to use a separate flag instead.

Signed-off-by: Simon Glass 
Tested-by: Aiden Park 
Reviewed-by: Aiden Park 
Reviewed-by: Bin Meng

x86: timer: Set up the timer in timer_early_get_count()

2019-11-02T23:20:27+00:00

This function can be called before the timer is set up. Make sure that the
init function is called so that it works correctly.

This is needed so that bootstage can work correctly in TPL.

Signed-off-by: Simon Glass 
Reviewed-by: Bin Meng

x86: tsc: Add support for native calibration of TSC freq

2019-02-12T06:37:16+00:00

Add native tsc calibration function. Calibrate the tsc timer the same
way as linux does in arch/x86/kernel/tsc.c.

Fixes booting for Apollo Lake processors.

Signed-off-by: Bernhard Messerklinger 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Bin Meng

timer: Remove DM_FLAG_PRE_RELOC flag in various drivers

2018-11-14T17:16:28+00:00

When a driver declares DM_FLAG_PRE_RELOC flag, it wishes to be
bound before relocation. However due to a bug in the DM core,
the flag only takes effect when devices are statically declared
via U_BOOT_DEVICE(). This bug has been fixed recently by commit
"dm: core: Respect drivers with the DM_FLAG_PRE_RELOC flag in
lists_bind_fdt()", but with the fix, it has a side effect that
all existing drivers that declared DM_FLAG_PRE_RELOC flag will
be bound before relocation now. This may expose potential boot
failure on some boards due to insufficient memory during the
pre-relocation stage.

To mitigate this potential impact, the following changes are
implemented:

- Remove DM_FLAG_PRE_RELOC flag in the driver, if the driver
  only supports configuration from device tree (OF_CONTROL)
- Keep DM_FLAG_PRE_RELOC flag in the driver only if the device
  is statically declared via U_BOOT_DEVICE()
- Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check, for
  drivers that support both statically declared devices and
  configuration from device tree

Signed-off-by: Bin Meng 
Reviewed-by: Simon Glass

x86: tsc: Introduce config option for early timer frequency

2018-10-22T09:51:45+00:00

So far the TSC timer driver supports trying hardware calibration first
and using device tree as last resort for its running frequency as the
normal timer.

However when it is used as the early timer, it only supports hardware
calibration and if it fails, the driver just panics. This introduces
a new config option to specify the early timer frequency in MHz and
it should be equal to the value described in the device tree.

Without this patch, the travis-ci testing on QEMU x86_64 target fails
each time after it finishes the 'bootefi selftest' as the test.py see
an error was emitted on the console like this:

  TSC frequency is ZERO
  resetting ...
  ### ERROR ### Please RESET the board ###

It's strange that this error is consistently seen on the travis-ci
machine, but only occasionally seen on my local machine (maybe 1 out
of 10). Since QEMU x86_64 target enables BOOTSTAGE support which uses
early timer, with this fix it should work without any failure.

Signed-off-by: Bin Meng 
Reviewed-by: Simon Glass

x86: tsc: Try hardware calibration first

2018-08-20T05:52:49+00:00

At present if TSC frequency is provided in the device tree, it takes
precedence over hardware calibration result. This swaps the order to
try hardware calibration first and uses device tree as last resort.

This can be helpful when a generic dts (eg: coreboot/efi payload) is
supposed to work on as many hardware as possible, including emulators
like QEMU where TSC hardware calibration sometimes fails.

Signed-off-by: Bin Meng 
Reviewed-by: Christian Gmeiner

x86: timer: tsc: Allow specifying clock rate from device tree again

2018-07-02T01:23:28+00:00

With the introduction of early timer support in the TSC driver,
the capability of getting clock rate from device tree was lost
unfortunately. Now we bring such functionality back, but with a
limitation that when TSC is used as early timer, specifying clock
rate from device tree does not work.

This fixes random boot failures seen on QEMU targets: printing "TSC
frequency is ZERO" and reset forever.

Signed-off-by: Bin Meng 
Reviewed-by: Simon Glass

x86: tsc: add support for reading CPU freq from cpuid

2018-06-13T01:50:57+00:00

Starting with cpuid level 0x16 (Skylake-based processors)
it is possible to get CPU base freq via cpuid.

This fixes booting on a skylake based system.

Signed-off-by: Christian Gmeiner 
Reviewed-by: Bin Meng 
[bmeng: fixed wrong indention of labels]
Signed-off-by: Bin Meng

SPDX: Convert all of our single license tags to Linux Kernel style

2018-05-07T13:34:12+00:00

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini