This patchset converts the CMSDK timer, watchdog and dualtimer devices
to use the Clock framework instead of an integer property specifying
a frequency in Hz. The series is quito a lot of patches but they
should be mostly small and I hope easy to review.
The motivation here is the upcoming Arm SSE-300 model: this has a
new kind of timer device, which I wanted to write in the modern style
with a Clock input. That meant the ARMSSE container object needed
to know about Clocks, so converting the existing devices it used
to Clocks seemed like a good first step.
The series as a whole is a migration compat break for the machines
involved: mps2-an385, mps2-an386, mps2-an500, mps2-an511, mps2-an505,
mps2-an521, musca-a, musca-b1, lm3s811evb, lm3s6965evb.
Series structure:
* patches adding new clock and ptimer API functions
* add tests for the devices
* add Clock inputs to devices, which do nothing for now
* wire up the clocks in the code that uses the devices
* make the devices use the clocks and ignore the frq properties
* remove the setting of the frq properties in code using the devices
* remove the frq properties from the devices
The new ptimer and clock functions are probably the most interesting part:
* ptimer_set_period_from_clock(ptimer, clk, divisor)
is for setting the period of a ptimer directly from a Clock (possibly
accounting for the frequency being divided by some integer first) --
this avoids possible rounding errors if we went via ptimer_set_period()
or ptimer_set_freq()
* clock_has_source()
returns true if an input Clock has been connected to an output clock;
this is for devices to be able to check in their realize method that
a mandatory clock was wired up by the board
(More detailed info and rationale in patches 1 and 2.)
A couple of bits of food-for-thought as a result of working with the
relatively-new Clock APIs:
* it might be worth thinking about whether we can have a fairly
lightweight implementation of a clock-divider or clock-multiplier,
because I feel they are pretty common. (For this series I opted
just to handle this via the ptimer_set_period_from_clock()
divisor argumuent.)
* it feels a little awkward that devices with an input Clock need
to do ptimer_set_period_from_clock() or similar both in their
realize method (to cope with fixed-frequency input clocks, because
the clock callback functions are not called when board setup code
creates and configures those) and in the clock callback function
(to cope with variable-frequency clocks)
* I found it odd that ptimer's period representation is 64.32
fixedpoint 2^-32 ns units, whereas Clock's is only 32.32
(so ptimer can handle much larger periods than Clock can.)
I forget why we didn't go for the same representation in Clock
as we have for ptimer...
* there's no MAINTAINERS entry for the Clock framework
I don't think these need to be blockers on this series, though.
thanks
-- PMM
Peter Maydell (25):
ptimer: Add new ptimer_set_period_from_clock() function
clock: Add new clock_has_source() function
tests: Add a simple test of the CMSDK APB timer
tests: Add a simple test of the CMSDK APB watchdog
tests: Add a simple test of the CMSDK APB dual timer
hw/timer/cmsdk-apb-timer: Rename CMSDKAPBTIMER struct to CMSDKAPBTimer
hw/timer/cmsdk-apb-timer: Add Clock input
hw/timer/cmsdk-apb-dualtimer: Add Clock input
hw/watchdog/cmsdk-apb-watchdog: Add Clock input
hw/arm/armsse: Rename "MAINCLK" property to "MAINCLK_FRQ"
hw/arm/armsse: Wire up clocks
hw/arm/mps2: Inline CMSDK_APB_TIMER creation
hw/arm/mps2: Create and connect SYSCLK Clock
hw/arm/mps2-tz: Create and connect ARMSSE Clocks
hw/arm/musca: Create and connect ARMSSE Clocks
hw/arm/stellaris: Convert SSYS to QOM device
hw/arm/stellaris: Create Clock input for watchdog
hw/timer/cmsdk-apb-timer: Convert to use Clock input
hw/timer/cmsdk-apb-dualtimer: Convert to use Clock input
hw/watchdog/cmsdk-apb-watchdog: Convert to use Clock input
tests/qtest/cmsdk-apb-watchdog-test: Test clock changes
hw/arm/armsse: Use Clock to set system_clock_scale
arm: Don't set freq properties on CMSDK timer, dualtimer, watchdog,
ARMSSE
arm: Remove frq properties on CMSDK timer, dualtimer, watchdog, ARMSSE
hw/arm/stellaris: Remove board-creation reset of STELLARIS_SYS
docs/devel/clocks.rst | 16 +++
include/hw/arm/armsse.h | 14 +-
include/hw/clock.h | 15 ++
include/hw/ptimer.h | 22 +++
include/hw/timer/cmsdk-apb-dualtimer.h | 5 +-
include/hw/timer/cmsdk-apb-timer.h | 34 ++---
include/hw/watchdog/cmsdk-apb-watchdog.h | 5 +-
include/qemu/typedefs.h | 1 +
hw/arm/armsse.c | 47 +++++--
hw/arm/mps2-tz.c | 14 +-
hw/arm/mps2.c | 28 +++-
hw/arm/musca.c | 13 +-
hw/arm/stellaris.c | 170 +++++++++++++++++------
hw/core/ptimer.c | 34 +++++
hw/timer/cmsdk-apb-dualtimer.c | 53 +++++--
hw/timer/cmsdk-apb-timer.c | 55 ++++----
hw/watchdog/cmsdk-apb-watchdog.c | 29 ++--
tests/qtest/cmsdk-apb-dualtimer-test.c | 131 +++++++++++++++++
tests/qtest/cmsdk-apb-timer-test.c | 76 ++++++++++
tests/qtest/cmsdk-apb-watchdog-test.c | 132 ++++++++++++++++++
MAINTAINERS | 3 +
tests/qtest/meson.build | 3 +
22 files changed, 758 insertions(+), 142 deletions(-)
create mode 100644 tests/qtest/cmsdk-apb-dualtimer-test.c
create mode 100644 tests/qtest/cmsdk-apb-timer-test.c
create mode 100644 tests/qtest/cmsdk-apb-watchdog-test.c
--
2.20.1
