<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/cpufreq/Makefile, branch master</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>x86/cpu, cpufreq: Remove AMD ELAN support</title>
<updated>2026-05-08T05:34:03+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2025-05-15T08:26:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=435ef16e69b9d7f9cdf460a4c2edd20bb47d51fa'/>
<id>435ef16e69b9d7f9cdf460a4c2edd20bb47d51fa</id>
<content type='text'>
Now that i486 and CONFIG_MELAN support has been removed upstream:

  8b793a92d862c ("x86/cpu: Remove M486/M486SX/ELAN support")

the CONFIG_ELAN_CPUFREQ and CONFIG_SC520_CPUFREQ cpufreq
drivers can be removed as well, as they depend on CONFIG_MELAN.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Cc: linux-pm@vger.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK)
Link: https://lore.kernel.org/r/20250425084216.3913608-8-mingo@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that i486 and CONFIG_MELAN support has been removed upstream:

  8b793a92d862c ("x86/cpu: Remove M486/M486SX/ELAN support")

the CONFIG_ELAN_CPUFREQ and CONFIG_SC520_CPUFREQ cpufreq
drivers can be removed as well, as they depend on CONFIG_MELAN.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: "Rafael J. Wysocki" &lt;rafael@kernel.org&gt;
Cc: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Cc: linux-pm@vger.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK)
Link: https://lore.kernel.org/r/20250425084216.3913608-8-mingo@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: omap: remove driver</title>
<updated>2026-01-08T20:26:34+00:00</updated>
<author>
<name>Andreas Kemnade</name>
<email>andreas@kemnade.info</email>
</author>
<published>2026-01-08T08:26:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0cc7933cbec80900bdbe658b72e2ba99187fe628'/>
<id>0cc7933cbec80900bdbe658b72e2ba99187fe628</id>
<content type='text'>
The omap-cpufreq driver is not used in the corresponding defconfigs.
The pseudo platform device to use it was removed by
commit cb6675d6a868 ("ARM: OMAP2+: Remove legacy PM init")
10 years ago.

Checking if there is any need to reactivate it:
For omap3, dra7 there is ti-cpufreq to create cpufreq-dt device
For omap2/4/5 there is cpufreq-dt-plat to create cpufreq-dt device.
For omap1 this driver cannot be selected at all.

So no users, no need to reactivate the driver somehow. So remove it.

Signed-off-by: Andreas Kemnade &lt;andreas@kemnade.info&gt;
Acked-by: Kevin Hilman &lt;khilman@baylibre.com&gt;
Link: https://patch.msgid.link/20260108-omap-cpufreq-removal-v1-1-8fe42f130f48@kemnade.info
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The omap-cpufreq driver is not used in the corresponding defconfigs.
The pseudo platform device to use it was removed by
commit cb6675d6a868 ("ARM: OMAP2+: Remove legacy PM init")
10 years ago.

Checking if there is any need to reactivate it:
For omap3, dra7 there is ti-cpufreq to create cpufreq-dt device
For omap2/4/5 there is cpufreq-dt-plat to create cpufreq-dt device.
For omap1 this driver cannot be selected at all.

So no users, no need to reactivate the driver somehow. So remove it.

Signed-off-by: Andreas Kemnade &lt;andreas@kemnade.info&gt;
Acked-by: Kevin Hilman &lt;khilman@baylibre.com&gt;
Link: https://patch.msgid.link/20260108-omap-cpufreq-removal-v1-1-8fe42f130f48@kemnade.info
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: cpufreq: powernv/tracing: Move powernv_throttle trace event</title>
<updated>2025-07-21T20:40:56+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2025-06-12T14:53:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=647fe16b46999258ce1aec41f4bdeabb4f0cc8e7'/>
<id>647fe16b46999258ce1aec41f4bdeabb4f0cc8e7</id>
<content type='text'>
As the trace event powernv_throttle is only used by the powernv code, move
it to a separate include file and have that code directly enable it.

Trace events can take up around 5K of memory when they are defined
regardless if they are used or not. It wastes memory to have them defined
in configurations where the tracepoint is not used.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/20250612145407.906308844@goodmis.org
Fixes: 0306e481d479a ("cpufreq: powernv/tracing: Add powernv_throttle tracepoint")
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Acked-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As the trace event powernv_throttle is only used by the powernv code, move
it to a separate include file and have that code directly enable it.

Trace events can take up around 5K of memory when they are defined
regardless if they are used or not. It wastes memory to have them defined
in configurations where the tracepoint is not used.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/20250612145407.906308844@goodmis.org
Fixes: 0306e481d479a ("cpufreq: powernv/tracing: Add powernv_throttle tracepoint")
Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Acked-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: Add Rust-based cpufreq-dt driver</title>
<updated>2025-05-20T05:51:11+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2024-02-01T05:06:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=06149d8f2216894cee86106c701d13141948f159'/>
<id>06149d8f2216894cee86106c701d13141948f159</id>
<content type='text'>
Introduce a Rust-based implementation of the cpufreq-dt driver, covering
most of the functionality provided by the existing C version. Some
features, such as retrieving platform data from `cpufreq-dt-platdev.c`,
are still pending.

The driver has been tested with QEMU, and frequency scaling works as
expected.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce a Rust-based implementation of the cpufreq-dt driver, covering
most of the functionality provided by the existing C version. Some
features, such as retrieving platform data from `cpufreq-dt-platdev.c`,
are still pending.

The driver has been tested with QEMU, and frequency scaling works as
expected.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: ppc_cbe: Remove powerpc Cell driver</title>
<updated>2025-02-26T15:45:09+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2024-12-18T10:55:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=16479389cfeb8031e81e3d4fecf98aaa2724386d'/>
<id>16479389cfeb8031e81e3d4fecf98aaa2724386d</id>
<content type='text'>
This driver can no longer be built since support for IBM Cell Blades was
removed, in particular CBE_RAS.

Remove the driver.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/20241218105523.416573-22-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This driver can no longer be built since support for IBM Cell Blades was
removed, in particular CBE_RAS.

Remove the driver.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/20241218105523.416573-22-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: airoha: Add EN7581 CPUFreq SMCCC driver</title>
<updated>2025-01-17T03:35:07+00:00</updated>
<author>
<name>Christian Marangi</name>
<email>ansuelsmth@gmail.com</email>
</author>
<published>2025-01-09T13:12:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=84cf9e541cccb8cb698518a9897942e8c78f1d83'/>
<id>84cf9e541cccb8cb698518a9897942e8c78f1d83</id>
<content type='text'>
Add simple CPU Freq driver for Airoha EN7581 SoC that control CPU
frequency scaling with SMC APIs and register a generic "cpufreq-dt"
device.

All CPU share the same frequency and can't be controlled independently.
CPU frequency is controlled by the attached PM domain.

Add SoC compatible to cpufreq-dt-plat block list as a dedicated cpufreq
driver is needed with OPP v2 nodes declared in DTS.

Signed-off-by: Christian Marangi &lt;ansuelsmth@gmail.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add simple CPU Freq driver for Airoha EN7581 SoC that control CPU
frequency scaling with SMC APIs and register a generic "cpufreq-dt"
device.

All CPU share the same frequency and can't be controlled independently.
CPU frequency is controlled by the attached PM domain.

Add SoC compatible to cpufreq-dt-plat block list as a dedicated cpufreq
driver is needed with OPP v2 nodes declared in DTS.

Signed-off-by: Christian Marangi &lt;ansuelsmth@gmail.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2024-11-23T18:44:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-23T18:44:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=42d9e8b7ccddee75989283cf7477305cfe3776ff'/>
<id>42d9e8b7ccddee75989283cf7477305cfe3776ff</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Rework kfence support for the HPT MMU to work on systems with &gt;= 16TB
   of RAM.

 - Remove the powerpc "maple" platform, used by the "Yellow Dog
   Powerstation".

 - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS,
   DYNAMIC_FTRACE_WITH_DIRECT_CALLS &amp; BPF Trampolines.

 - Add support for running KVM nested guests on Power11.

 - Other small features, cleanups and fixes.

Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa
Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert
Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard,
Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek,
Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao,
Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash,
Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen
Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum,
Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao.

* tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits)
  EDAC/powerpc: Remove PPC_MAPLE drivers
  powerpc/perf: Add per-task/process monitoring to vpa_pmu driver
  powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch
  docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu
  powerpc/perf: Add perf interface to expose vpa counters
  MAINTAINERS: powerpc: Mark Maddy as "M"
  powerpc/Makefile: Allow overriding CPP
  powerpc-km82xx.c: replace of_node_put() with __free
  ps3: Correct some typos in comments
  powerpc/kexec: Fix return of uninitialized variable
  macintosh: Use common error handling code in via_pmu_led_init()
  powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type()
  powerpc: remove dead config options for MPC85xx platform support
  powerpc/xive: Use cpumask_intersects()
  selftests/powerpc: Remove the path after initialization.
  powerpc/xmon: symbol lookup length fixed
  powerpc/ep8248e: Use %pa to format resource_size_t
  powerpc/ps3: Reorganize kerneldoc parameter names
  KVM: PPC: Book3S HV: Fix kmv -&gt; kvm typo
  powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull powerpc updates from Michael Ellerman:

 - Rework kfence support for the HPT MMU to work on systems with &gt;= 16TB
   of RAM.

 - Remove the powerpc "maple" platform, used by the "Yellow Dog
   Powerstation".

 - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS,
   DYNAMIC_FTRACE_WITH_DIRECT_CALLS &amp; BPF Trampolines.

 - Add support for running KVM nested guests on Power11.

 - Other small features, cleanups and fixes.

Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa
Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert
Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard,
Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek,
Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao,
Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash,
Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen
Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum,
Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao.

* tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits)
  EDAC/powerpc: Remove PPC_MAPLE drivers
  powerpc/perf: Add per-task/process monitoring to vpa_pmu driver
  powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch
  docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu
  powerpc/perf: Add perf interface to expose vpa counters
  MAINTAINERS: powerpc: Mark Maddy as "M"
  powerpc/Makefile: Allow overriding CPP
  powerpc-km82xx.c: replace of_node_put() with __free
  ps3: Correct some typos in comments
  powerpc/kexec: Fix return of uninitialized variable
  macintosh: Use common error handling code in via_pmu_led_init()
  powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type()
  powerpc: remove dead config options for MPC85xx platform support
  powerpc/xive: Use cpumask_intersects()
  selftests/powerpc: Remove the path after initialization.
  powerpc/xmon: symbol lookup length fixed
  powerpc/ep8248e: Use %pa to format resource_size_t
  powerpc/ps3: Reorganize kerneldoc parameter names
  KVM: PPC: Book3S HV: Fix kmv -&gt; kvm typo
  powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: maple: Remove maple driver</title>
<updated>2024-11-13T01:02:23+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2024-11-12T08:51:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fae2987e67786a6358c0ef47189b12ff19e9543a'/>
<id>fae2987e67786a6358c0ef47189b12ff19e9543a</id>
<content type='text'>
This driver is no longer buildable since the PPC_MAPLE platform was
removed, see commit 62f8f307c80e ("powerpc/64: Remove maple platform").

Remove the driver.

Note that the comment in the driver says it supports "SMU &amp; 970FX
based G5 Macs", but that's not true, that comment was copied from
pmac64-cpufreq.c, which still exists and continues to support those
machines.

Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241112085148.415574-1-mpe@ellerman.id.au

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This driver is no longer buildable since the PPC_MAPLE platform was
removed, see commit 62f8f307c80e ("powerpc/64: Remove maple platform").

Remove the driver.

Note that the comment in the driver says it supports "SMU &amp; 970FX
based G5 Macs", but that's not true, that comment was copied from
pmac64-cpufreq.c, which still exists and continues to support those
machines.

Acked-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241112085148.415574-1-mpe@ellerman.id.au

</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: add virtual-cpufreq driver</title>
<updated>2024-10-29T06:35:14+00:00</updated>
<author>
<name>David Dai</name>
<email>davidai@google.com</email>
</author>
<published>2024-09-19T00:08:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4fd06a5358e0d888d1bf23d274971ea7d1f45aad'/>
<id>4fd06a5358e0d888d1bf23d274971ea7d1f45aad</id>
<content type='text'>
Introduce a virtualized cpufreq driver for guest kernels to improve
performance and power of workloads within VMs.

This driver does two main things:

1. Sends the frequency of vCPUs as a hint to the host. The host uses the
hint to schedule the vCPU threads and decide physical CPU frequency.

2. If a VM does not support a virtualized FIE(like AMUs), it queries the
host CPU frequency by reading a MMIO region of a virtual cpufreq device
to update the guest's frequency scaling factor periodically. This enables
accurate Per-Entity Load Tracking for tasks running in the guest.

Co-developed-by: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: David Dai &lt;davidai@google.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce a virtualized cpufreq driver for guest kernels to improve
performance and power of workloads within VMs.

This driver does two main things:

1. Sends the frequency of vCPUs as a hint to the host. The host uses the
hint to schedule the vCPU threads and decide physical CPU frequency.

2. If a VM does not support a virtualized FIE(like AMUs), it queries the
host CPU frequency by reading a MMIO region of a virtual cpufreq device
to update the guest's frequency scaling factor periodically. This enables
accurate Per-Entity Load Tracking for tasks running in the guest.

Co-developed-by: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: Saravana Kannan &lt;saravanak@google.com&gt;
Signed-off-by: David Dai &lt;davidai@google.com&gt;
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpufreq: Add Loongson-3 CPUFreq driver support</title>
<updated>2024-07-09T03:15:43+00:00</updated>
<author>
<name>Huacai Chen</name>
<email>chenhuacai@loongson.cn</email>
</author>
<published>2024-07-05T06:06:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ccf51454145bffd98e31cdbe54a4262473c609e2'/>
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Some of LoongArch processors (Loongson-3 series) support DVFS, their
IOCSR.FEATURES has IOCSRF_FREQSCALE set. And they has a micro-core in
the package called SMC (System Management Controller), which can be
used to detect temperature, control fans, scale frequency and voltage,
etc.

The Loongson-3 CPUFreq driver is very simple now, it communicate with
SMC, get DVFS info, set target frequency from CPUFreq core, and so on.

There is a command list to interact with SMC, widely-used commands in
the CPUFreq driver include:

CMD_GET_VERSION: Get SMC firmware version.

CMD_GET_FEATURE: Get enabled SMC features.

CMD_SET_FEATURE: Enable SMC features, such as basic DVFS, BOOST.

CMD_GET_FREQ_LEVEL_NUM: Get the number of all frequency levels.

CMD_GET_FREQ_BOOST_LEVEL: Get the first boost frequency level.

CMD_GET_FREQ_LEVEL_INFO: Get the detail info of a frequency level.

CMD_GET_FREQ_INFO: Get the current frequency.

CMD_SET_FREQ_INFO: Set the target frequency.

In future we will add automatic frequency scaling, which is similar to
Intel's HWP (HardWare P-State).

Signed-off-by: Binbin Zhou &lt;zhoubinbin@loongson.cn&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
[ Viresh: Minor formatting cleanups, change return type of exit() to
	  void and use devm_mutex_init() ]
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
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Some of LoongArch processors (Loongson-3 series) support DVFS, their
IOCSR.FEATURES has IOCSRF_FREQSCALE set. And they has a micro-core in
the package called SMC (System Management Controller), which can be
used to detect temperature, control fans, scale frequency and voltage,
etc.

The Loongson-3 CPUFreq driver is very simple now, it communicate with
SMC, get DVFS info, set target frequency from CPUFreq core, and so on.

There is a command list to interact with SMC, widely-used commands in
the CPUFreq driver include:

CMD_GET_VERSION: Get SMC firmware version.

CMD_GET_FEATURE: Get enabled SMC features.

CMD_SET_FEATURE: Enable SMC features, such as basic DVFS, BOOST.

CMD_GET_FREQ_LEVEL_NUM: Get the number of all frequency levels.

CMD_GET_FREQ_BOOST_LEVEL: Get the first boost frequency level.

CMD_GET_FREQ_LEVEL_INFO: Get the detail info of a frequency level.

CMD_GET_FREQ_INFO: Get the current frequency.

CMD_SET_FREQ_INFO: Set the target frequency.

In future we will add automatic frequency scaling, which is similar to
Intel's HWP (HardWare P-State).

Signed-off-by: Binbin Zhou &lt;zhoubinbin@loongson.cn&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
[ Viresh: Minor formatting cleanups, change return type of exit() to
	  void and use devm_mutex_init() ]
Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
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