linux/drivers/cpufreq/Kconfig.arm
Arnd Bergmann f46f11dc1e ARM SCMI support for v4.17
ARM System Control and Management Interface(SCMI)[1] is more flexible and
 easily extensible than any of the existing interfaces.
 
 Few existing as well as future ARM platforms provide micro-controllers
 to abstract various power and other system management tasks which have
 similar interfaces, both in terms of the functions that are provided by
 them, and in terms of how requests are communicated to them.
 
 There are quite a few protocols like ARM SCPI, TI SCI, QCOM RPM, Nvidia Tegra
 BPMP, and so on already. This specification is to standardize and avoid any
 further fragmentation in the design of such interface by various vendors.
 
 The current SCMI driver implementation is very basic and initial support.
 It lacks support for notifications, asynchronous/delayed response, perf/power
 statistics region and sensor register region.
 
 Mailbox is the only form of transport supported currently in the driver.
 SCMI supports interrupt based mailbox communication, where, on completion
 of the processing of a message, the caller receives an interrupt as well as
 polling for completion.
 
 SCMI is designed to minimize the dependency on the mailbox/transport
 hardware. So in terms of SCMI, each channel in the mailbox includes
 memory area, doorbell and completion interrupt.
 
 However the doorbell and completion interrupt is highly mailbox dependent
 which was bit of controversial as part of SCMI/mailbox discussions.
 
 Arnd and me discussed about the few aspects of SCMI and the mailbox framework:
 
 1. Use of mailbox framework for doorbell type mailbox controller:
    - Such hardware may not require any data to be sent to signal the remote
      about the presence of a message. The channel will have in-built
      information on how to trigger the signal to the remote.
      There are few mailbox controller drivers which are purely doorbell based.
      e.g.QCOM IPC, STM, Tegra, ACPI PCC,..etc
 
 2. Supporting other mailbox controller:
    - SCMI just needs a mechanism to signal the remote firmware. Such
      controller may need fixed message to be sent to trigger a doorbell.
      In such case we may need to get that data from DT and pass the same
      to the controller. It's not covered in the current DT binding, but
      can be extended as optional property in future.
 
      However handling notifications may be interesting on such mailbox, but
      again there is no way to interpret what the data field(remote message)
      means, it could be a bit mask or a number or don't-care.
 
 Arnd mentioned that he doesn't like the way the mailbox binding deals
 with doorbell-type hardware, but we do have quite a few precedent drivers
 already and changing the binding to add a data field would not make it any
 better, but could cause other problems. So he is happy with the status quo
 of SCMI implementation.
 
 [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0056a/index.html
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Merge tag 'scmi-updates-4.17' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into next/drivers

Pull "ARM SCMI support for v4.17" from Sudeep Holla:

ARM System Control and Management Interface(SCMI)[1] is more flexible and
easily extensible than any of the existing interfaces.

Few existing as well as future ARM platforms provide micro-controllers
to abstract various power and other system management tasks which have
similar interfaces, both in terms of the functions that are provided by
them, and in terms of how requests are communicated to them.

There are quite a few protocols like ARM SCPI, TI SCI, QCOM RPM, Nvidia Tegra
BPMP, and so on already. This specification is to standardize and avoid any
further fragmentation in the design of such interface by various vendors.

The current SCMI driver implementation is very basic and initial support.
It lacks support for notifications, asynchronous/delayed response, perf/power
statistics region and sensor register region.

Mailbox is the only form of transport supported currently in the driver.
SCMI supports interrupt based mailbox communication, where, on completion
of the processing of a message, the caller receives an interrupt as well as
polling for completion.

SCMI is designed to minimize the dependency on the mailbox/transport
hardware. So in terms of SCMI, each channel in the mailbox includes
memory area, doorbell and completion interrupt.

However the doorbell and completion interrupt is highly mailbox dependent
which was bit of controversial as part of SCMI/mailbox discussions.

Arnd and me discussed about the few aspects of SCMI and the mailbox framework:

1. Use of mailbox framework for doorbell type mailbox controller:
   - Such hardware may not require any data to be sent to signal the remote
     about the presence of a message. The channel will have in-built
     information on how to trigger the signal to the remote.
     There are few mailbox controller drivers which are purely doorbell based.
     e.g.QCOM IPC, STM, Tegra, ACPI PCC,..etc

2. Supporting other mailbox controller:
   - SCMI just needs a mechanism to signal the remote firmware. Such
     controller may need fixed message to be sent to trigger a doorbell.
     In such case we may need to get that data from DT and pass the same
     to the controller. It's not covered in the current DT binding, but
     can be extended as optional property in future.

     However handling notifications may be interesting on such mailbox, but
     again there is no way to interpret what the data field(remote message)
     means, it could be a bit mask or a number or don't-care.

Arnd mentioned that he doesn't like the way the mailbox binding deals
with doorbell-type hardware, but we do have quite a few precedent drivers
already and changing the binding to add a data field would not make it any
better, but could cause other problems. So he is happy with the status quo
of SCMI implementation.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0056a/index.html

* tag 'scmi-updates-4.17' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  cpufreq: scmi: add support for fast frequency switching
  cpufreq: add support for CPU DVFS based on SCMI message protocol
  hwmon: add support for sensors exported via ARM SCMI
  hwmon: (core) Add hwmon_max to hwmon_sensor_types enumeration
  clk: add support for clocks provided by SCMI
  firmware: arm_scmi: add device power domain support using genpd
  firmware: arm_scmi: add per-protocol channels support using idr objects
  firmware: arm_scmi: refactor in preparation to support per-protocol channels
  firmware: arm_scmi: add option for polling based performance domain operations
  firmware: arm_scmi: add support for polling based SCMI transfers
  firmware: arm_scmi: probe and initialise all the supported protocols
  firmware: arm_scmi: add initial support for sensor protocol
  firmware: arm_scmi: add initial support for power protocol
  firmware: arm_scmi: add initial support for clock protocol
  firmware: arm_scmi: add initial support for performance protocol
  firmware: arm_scmi: add scmi protocol bus to enumerate protocol devices
  firmware: arm_scmi: add common infrastructure and support for base protocol
  firmware: arm_scmi: add basic driver infrastructure for SCMI
  dt-bindings: arm: add support for ARM System Control and Management Interface(SCMI) protocol
  dt-bindings: mailbox: add support for mailbox client shared memory
2018-03-07 16:45:07 +01:00

312 lines
8.8 KiB
Plaintext

#
# ARM CPU Frequency scaling drivers
#
config ACPI_CPPC_CPUFREQ
tristate "CPUFreq driver based on the ACPI CPPC spec"
depends on ACPI_PROCESSOR
select ACPI_CPPC_LIB
help
This adds a CPUFreq driver which uses CPPC methods
as described in the ACPIv5.1 spec. CPPC stands for
Collaborative Processor Performance Controls. It
is based on an abstract continuous scale of CPU
performance values which allows the remote power
processor to flexibly optimize for power and
performance. CPPC relies on power management firmware
support for its operation.
If in doubt, say N.
config ARM_ARMADA_37XX_CPUFREQ
tristate "Armada 37xx CPUFreq support"
depends on ARCH_MVEBU
help
This adds the CPUFreq driver support for Marvell Armada 37xx SoCs.
The Armada 37xx PMU supports 4 frequency and VDD levels.
# big LITTLE core layer and glue drivers
config ARM_BIG_LITTLE_CPUFREQ
tristate "Generic ARM big LITTLE CPUfreq driver"
depends on (ARM_CPU_TOPOLOGY || ARM64) && HAVE_CLK
# if CPU_THERMAL is on and THERMAL=m, ARM_BIT_LITTLE_CPUFREQ cannot be =y
depends on !CPU_THERMAL || THERMAL
select PM_OPP
help
This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.
config ARM_DT_BL_CPUFREQ
tristate "Generic probing via DT for ARM big LITTLE CPUfreq driver"
depends on ARM_BIG_LITTLE_CPUFREQ && OF
help
This enables probing via DT for Generic CPUfreq driver for ARM
big.LITTLE platform. This gets frequency tables from DT.
config ARM_SCPI_CPUFREQ
tristate "SCPI based CPUfreq driver"
depends on ARM_SCPI_PROTOCOL && COMMON_CLK_SCPI
help
This adds the CPUfreq driver support for ARM platforms using SCPI
protocol for CPU power management.
This driver uses SCPI Message Protocol driver to interact with the
firmware providing the CPU DVFS functionality.
config ARM_VEXPRESS_SPC_CPUFREQ
tristate "Versatile Express SPC based CPUfreq driver"
depends on ARM_BIG_LITTLE_CPUFREQ && ARCH_VEXPRESS_SPC
help
This add the CPUfreq driver support for Versatile Express
big.LITTLE platforms using SPC for power management.
config ARM_BRCMSTB_AVS_CPUFREQ
tristate "Broadcom STB AVS CPUfreq driver"
depends on ARCH_BRCMSTB || COMPILE_TEST
default y
help
Some Broadcom STB SoCs use a co-processor running proprietary firmware
("AVS") to handle voltage and frequency scaling. This driver provides
a standard CPUfreq interface to to the firmware.
Say Y, if you have a Broadcom SoC with AVS support for DFS or DVFS.
config ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
bool "Broadcom STB AVS CPUfreq driver sysfs debug capability"
depends on ARM_BRCMSTB_AVS_CPUFREQ
help
Enabling this option turns on debug support via sysfs under
/sys/kernel/debug/brcmstb-avs-cpufreq. It is possible to read all and
write some AVS mailbox registers through sysfs entries.
If in doubt, say N.
config ARM_EXYNOS5440_CPUFREQ
tristate "SAMSUNG EXYNOS5440"
depends on SOC_EXYNOS5440
depends on HAVE_CLK && OF
select PM_OPP
default y
help
This adds the CPUFreq driver for Samsung EXYNOS5440
SoC. The nature of exynos5440 clock controller is
different than previous exynos controllers so not using
the common exynos framework.
If in doubt, say N.
config ARM_HIGHBANK_CPUFREQ
tristate "Calxeda Highbank-based"
depends on ARCH_HIGHBANK && CPUFREQ_DT && REGULATOR
default m
help
This adds the CPUFreq driver for Calxeda Highbank SoC
based boards.
If in doubt, say N.
config ARM_IMX6Q_CPUFREQ
tristate "Freescale i.MX6 cpufreq support"
depends on ARCH_MXC
depends on REGULATOR_ANATOP
select PM_OPP
help
This adds cpufreq driver support for Freescale i.MX6 series SoCs.
If in doubt, say N.
config ARM_KIRKWOOD_CPUFREQ
def_bool MACH_KIRKWOOD
help
This adds the CPUFreq driver for Marvell Kirkwood
SoCs.
config ARM_MEDIATEK_CPUFREQ
tristate "CPU Frequency scaling support for MediaTek SoCs"
depends on ARCH_MEDIATEK && REGULATOR
depends on !CPU_THERMAL || THERMAL
select PM_OPP
help
This adds the CPUFreq driver support for MediaTek SoCs.
config ARM_OMAP2PLUS_CPUFREQ
bool "TI OMAP2+"
depends on ARCH_OMAP2PLUS
default ARCH_OMAP2PLUS
config ARM_S3C_CPUFREQ
bool
help
Internal configuration node for common cpufreq on Samsung SoC
config ARM_S3C24XX_CPUFREQ
bool "CPUfreq driver for Samsung S3C24XX series CPUs (EXPERIMENTAL)"
depends on ARCH_S3C24XX
select ARM_S3C_CPUFREQ
help
This enables the CPUfreq driver for the Samsung S3C24XX family
of CPUs.
For details, take a look at <file:Documentation/cpu-freq>.
If in doubt, say N.
config ARM_S3C24XX_CPUFREQ_DEBUG
bool "Debug CPUfreq Samsung driver core"
depends on ARM_S3C24XX_CPUFREQ
help
Enable s3c_freq_dbg for the Samsung S3C CPUfreq core
config ARM_S3C24XX_CPUFREQ_IODEBUG
bool "Debug CPUfreq Samsung driver IO timing"
depends on ARM_S3C24XX_CPUFREQ
help
Enable s3c_freq_iodbg for the Samsung S3C CPUfreq core
config ARM_S3C24XX_CPUFREQ_DEBUGFS
bool "Export debugfs for CPUFreq"
depends on ARM_S3C24XX_CPUFREQ && DEBUG_FS
help
Export status information via debugfs.
config ARM_S3C2410_CPUFREQ
bool
depends on ARM_S3C24XX_CPUFREQ && CPU_S3C2410
select S3C2410_CPUFREQ_UTILS
help
CPU Frequency scaling support for S3C2410
config ARM_S3C2412_CPUFREQ
bool
depends on ARM_S3C24XX_CPUFREQ && CPU_S3C2412
default y
select S3C2412_IOTIMING
help
CPU Frequency scaling support for S3C2412 and S3C2413 SoC CPUs.
config ARM_S3C2416_CPUFREQ
bool "S3C2416 CPU Frequency scaling support"
depends on CPU_S3C2416
help
This adds the CPUFreq driver for the Samsung S3C2416 and
S3C2450 SoC. The S3C2416 supports changing the rate of the
armdiv clock source and also entering a so called dynamic
voltage scaling mode in which it is possible to reduce the
core voltage of the CPU.
If in doubt, say N.
config ARM_S3C2416_CPUFREQ_VCORESCALE
bool "Allow voltage scaling for S3C2416 arm core"
depends on ARM_S3C2416_CPUFREQ && REGULATOR
help
Enable CPU voltage scaling when entering the dvs mode.
It uses information gathered through existing hardware and
tests but not documented in any datasheet.
If in doubt, say N.
config ARM_S3C2440_CPUFREQ
bool "S3C2440/S3C2442 CPU Frequency scaling support"
depends on ARM_S3C24XX_CPUFREQ && (CPU_S3C2440 || CPU_S3C2442)
select S3C2410_CPUFREQ_UTILS
default y
help
CPU Frequency scaling support for S3C2440 and S3C2442 SoC CPUs.
config ARM_S3C64XX_CPUFREQ
bool "Samsung S3C64XX"
depends on CPU_S3C6410
default y
help
This adds the CPUFreq driver for Samsung S3C6410 SoC.
If in doubt, say N.
config ARM_S5PV210_CPUFREQ
bool "Samsung S5PV210 and S5PC110"
depends on CPU_S5PV210
default y
help
This adds the CPUFreq driver for Samsung S5PV210 and
S5PC110 SoCs.
If in doubt, say N.
config ARM_SA1100_CPUFREQ
bool
config ARM_SA1110_CPUFREQ
bool
config ARM_SCMI_CPUFREQ
tristate "SCMI based CPUfreq driver"
depends on ARM_SCMI_PROTOCOL || COMPILE_TEST
select PM_OPP
help
This adds the CPUfreq driver support for ARM platforms using SCMI
protocol for CPU power management.
This driver uses SCMI Message Protocol driver to interact with the
firmware providing the CPU DVFS functionality.
config ARM_SPEAR_CPUFREQ
bool "SPEAr CPUFreq support"
depends on PLAT_SPEAR
default y
help
This adds the CPUFreq driver support for SPEAr SOCs.
config ARM_STI_CPUFREQ
tristate "STi CPUFreq support"
depends on SOC_STIH407
help
This driver uses the generic OPP framework to match the running
platform with a predefined set of suitable values. If not provided
we will fall-back so safe-values contained in Device Tree. Enable
this config option if you wish to add CPUFreq support for STi based
SoCs.
config ARM_TANGO_CPUFREQ
bool
depends on CPUFREQ_DT && ARCH_TANGO
default y
config ARM_TEGRA20_CPUFREQ
bool "Tegra20 CPUFreq support"
depends on ARCH_TEGRA
default y
help
This adds the CPUFreq driver support for Tegra20 SOCs.
config ARM_TEGRA124_CPUFREQ
tristate "Tegra124 CPUFreq support"
depends on ARCH_TEGRA && CPUFREQ_DT && REGULATOR
default y
help
This adds the CPUFreq driver support for Tegra124 SOCs.
config ARM_TEGRA186_CPUFREQ
tristate "Tegra186 CPUFreq support"
depends on ARCH_TEGRA && TEGRA_BPMP
help
This adds the CPUFreq driver support for Tegra186 SOCs.
config ARM_TI_CPUFREQ
bool "Texas Instruments CPUFreq support"
depends on ARCH_OMAP2PLUS
help
This driver enables valid OPPs on the running platform based on
values contained within the SoC in use. Enable this in order to
use the cpufreq-dt driver on all Texas Instruments platforms that
provide dt based operating-points-v2 tables with opp-supported-hw
data provided. Required for cpufreq support on AM335x, AM437x,
DRA7x, and AM57x platforms.
config ARM_PXA2xx_CPUFREQ
tristate "Intel PXA2xx CPUfreq driver"
depends on PXA27x || PXA25x
help
This add the CPUFreq driver support for Intel PXA2xx SOCs.
If in doubt, say N.