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path: root/drivers/pci/host/pci-xgene.c
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2017-04-28PCI: Don't allow unbinding host controllers that aren't preparedBrian Norris
Many PCI host controller drivers aren't prepared to have their devices unbound from them forcefully (e.g., through /sys/.../<driver>/unbind), as they don't provide any driver .remove callback, where they'd detach the root bus, release resources, etc. Keeping the driver built in (i.e., not a loadable module) is not enough; and providing no .remove callback just means we don't do any teardown. To rule out the possibility of unbinding a device via sysfs, we need to set the ".suppress_bind_attrs" field. I found the suspect drivers via the following search: git grep -l platform_driver $(git grep -L -e '\.remove' -e suppress_bind_attrs drivers/pci/) Then I inspected them to ensure that (a) they set up a PCI bus in their probe() and (b) they don't have a remove() callback for undoing the setup Suggested-by: Bjorn Helgaas <helgaas@kernel.org> Signed-off-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-04-24PCI: xgene: Update PCI config space remap functionLorenzo Pieralisi
PCI configuration space should be mapped with a memory region type that generates on the CPU host bus non-posted write transations. Update the driver to use the devm_pci_remap_cfg* interface to make sure the correct memory mappings for PCI configuration space are used. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Tanmay Inamdar <tinamdar@apm.com>
2017-02-10PCI: xgene: Configure PCIe MPS settingsBjorn Helgaas
Make sure PCIe MPS settings are valid when we enumerate a new hierarchy. Based-on-patch-by: Jon Mason <jon.mason@broadcom.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-01-30PCI: xgene: Fix double free on init errorDan Carpenter
The "port" variable was allocated with devm_kzalloc() so if we free it with kfree() it will be freed twice. Also I changed it to propogate the error from devm_ioremap_resource() instead of returning -ENOMEM. Fixes: c5d460396100 ("PCI: Add MCFG quirks for X-Gene host controller") Also-posted-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Tanmay Inamdar <tinamdar@apm.com>
2016-12-06PCI: Add MCFG quirks for X-Gene host controllerDuc Dang
PCIe controllers in X-Gene SoCs are not ECAM compliant: software needs to configure additional controller's register to address device at bus:dev:function. Add a quirk to discover controller MMIO register space and configure controller registers to select and address the target secondary device. The quirk will only be applied for X-Gene PCIe MCFG table with OEM revison 1, 2, 3 or 4 (PCIe controller v1 and v2 on X-Gene SoCs). Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-10-11PCI: xgene: Add register accessorsBjorn Helgaas
Add device-specific register accessors for consistency across host drivers. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-10-11PCI: xgene: Pass struct xgene_pcie_port to setup functionsBjorn Helgaas
Pass the struct xgene_pcie_port pointer, not addresses, to setup functions. This enables future simplifications. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-10-11PCI: xgene: Remove unused platform dataBjorn Helgaas
The xgene driver never uses the platform drvdata pointer, so don't bother setting it. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-10-10PCI: xgene: Add local struct device pointersBjorn Helgaas
Use a local "struct device *dev" for brevity and consistency with other drivers. No functional change intended. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-08-01Merge branches 'pci/demodularize-hosts' and 'pci/host-request-windows' into nextBjorn Helgaas
* pci/demodularize-hosts: PCI: xgene: Make explicitly non-modular PCI: thunder-pem: Make explicitly non-modular PCI: thunder-ecam: Make explicitly non-modular PCI: tegra: Make explicitly non-modular PCI: rcar-gen2: Make explicitly non-modular PCI: rcar: Make explicitly non-modular PCI: mvebu: Make explicitly non-modular PCI: layerscape: Make explicitly non-modular PCI: keystone: Make explicitly non-modular PCI: hisi: Make explicitly non-modular PCI: generic: Make explicitly non-modular PCI: designware-plat: Make it explicitly non-modular PCI: artpec6: Make explicitly non-modular PCI: armada8k: Make explicitly non-modular PCI: artpec: Add PCI_MSI_IRQ_DOMAIN dependency PCI: artpec: Add Axis ARTPEC-6 PCIe controller driver PCI: Add DT binding for Axis ARTPEC-6 PCIe controller PCI: generic: Select IRQ_DOMAIN * pci/host-request-windows: PCI: versatile: Simplify host bridge window iteration PCI: versatile: Request host bridge window resources with core function PCI: tegra: Request host bridge window resources with core function PCI: tegra: Remove top-level resource from hierarchy PCI: rcar: Simplify host bridge window iteration PCI: rcar: Request host bridge window resources with core function PCI: rcar Gen2: Request host bridge window resources PCI: rcar: Drop gen2 dummy I/O port region ARM: Make PCI I/O space optional PCI: mvebu: Request host bridge window resources with core function PCI: generic: Simplify host bridge window iteration PCI: generic: Request host bridge window resources with core function PCI: altera: Simplify host bridge window iteration PCI: altera: Request host bridge window resources with core function PCI: xilinx-nwl: Use dev_printk() when possible PCI: xilinx-nwl: Request host bridge window resources PCI: xilinx-nwl: Free bridge resource list on failure PCI: xilinx: Request host bridge window resources PCI: xilinx: Free bridge resource list on failure PCI: xgene: Request host bridge window resources PCI: xgene: Free bridge resource list on failure PCI: iproc: Request host bridge window resources PCI: designware: Simplify host bridge window iteration PCI: designware: Request host bridge window resources PCI: designware: Free bridge resource list on failure PCI: Add devm_request_pci_bus_resources()
2016-08-01PCI: xgene: Make explicitly non-modularPaul Gortmaker
This code is not being built as a module by anyone: drivers/pci/host/Kconfig:config PCI_XGENE drivers/pci/host/Kconfig: bool "X-Gene PCIe controller" Remove uses of MODULE_DESCRIPTION(), MODULE_AUTHOR(), MODULE_LICENSE(), etc., so that when reading the driver there is no doubt it is builtin-only. The information is preserved in comments at the top of the file. Replace module_platform_driver() with builtin_platform_driver(), which uses the same init level priority, so init ordering is unchanged. [bhelgaas: changelog] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Tanmay Inamdar <tinamdar@apm.com>
2016-06-20PCI: xgene: Request host bridge window resourcesBjorn Helgaas
Request host bridge window resources so they appear in ioport_resource and iomem_resource and are reflected in /proc/ioports and /proc/iomem. For example, the following entries did not previously appear in /proc/iomem: e180000000-e1ffffffff : /soc/pcie@1f2b0000 e180000000-e182ffffff : PCI Bus 0000:01 e180000000-e181ffffff : 0000:01:00.0 e182000000-e1820fffff : 0000:01:00.0 e182100000-e1821fffff : 0000:01:00.0 f000000000-ffffffffff : /soc/pcie@1f2b0000 Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-20PCI: xgene: Free bridge resource list on failureBjorn Helgaas
of_pci_get_host_bridge_resources() allocates a list of resources for host bridge windows. If we fail after allocating that list, free it before we return error. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-09-25PCI/MSI: xgene: Remove msi_controller assignmentDuc Dang
After 8d63bc7beaee ("PCI/MSI: pci-xgene-msi: Get rid of struct msi_controller"), it is no longer required to assign msi_controller for X-Gene PCIe host bridge to support MSI. Remove this unnecessary code. This also avoids a warning message ("failed to enable MSI") during boot. [bhelgaas: changelog] Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Tanmay Inamdar <tinamdar@apm.com>
2015-08-28Merge branches 'pci/enumeration' and 'pci/misc' into nextBjorn Helgaas
* pci/enumeration: PCI: Set MPS to match upstream bridge PCI: Move MPS configuration check to pci_configure_device() PCI: Drop references acquired by of_parse_phandle() PCI/MSI: Remove unused pcibios_msi_controller() hook ARM/PCI: Remove msi_controller from struct pci_sys_data ARM/PCI, designware, xilinx: Use pci_scan_root_bus_msi() PCI: Add pci_scan_root_bus_msi() ARM/PCI: Replace panic with WARN messages on failures PCI: generic: Add arm64 support PCI: Build setup-irq.o for arm64 PCI: generic: Remove dependency on ARM-specific struct hw_pci ARM/PCI: Set MPS before pci_bus_add_devices() * pci/misc: PCI: Disable async suspend/resume for JMicron multi-function SATA/AHCI
2015-08-20PCI: Drop references acquired by of_parse_phandle()Bjorn Helgaas
of_parse_phandle() returns a device_node pointer with the refcount incremented. We should dispose of this reference when we're finished. Drop the reference acquired by of_parse_phandle(). Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2015-07-21PCI: xgene: Add support for a 64-bit prefetchable memory windowDuc Dang
X-Gene PCIe controller has registers to support multiple memory ranges. Add support for a 64-bit prefetchable memory window. [bhelgaas: changelog] Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Tanmay Inamdar <tinamdar@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-06-18PCI: xgene: Allow config access to Root Port even when link is downDuc Dang
Previously, when a Root Port's link was down, we didn't allow config access to the Root Port, which meant that if the Root Port led to an empty slot, "lspci" didn't even show the Root Port. Allow config access to Root Port even when link is down. [bhelgaas: changelog, fold in unused var fix] Suggested-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Tanmay Inamdar <tinamdar@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-06-18PCI: xgene: Disable Configuration Request Retry Status for v1 siliconDuc Dang
When a CPU reads the Vendor and Device ID of a non-existent device, the controller should fabricate return data of 0xFFFFFFFF. Configuration Request Retry Status (CRS) is not applicable in this case because the device doesn't exist at all. The X-Gene v1 PCIe controller has a bug in the CRS logic such that when CRS is enabled, it fabricates return data of 0xFFFF0001 for this case, which means "the device exists but is not ready." That causes the PCI core to retry the read until it times out after 60 seconds. Disable CRS capability advertisement by clearing the CRS Software Visibility bit in the Root Capabilities Register. [bhelgaas: changelog and comment] Tested-by: Ian Campbell <ian.campbell@citrix.com> Tested-by: Marcin Juszkiewicz <mjuszkiewicz@redhat.com> Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Tanmay Inamdar <tinamdar@apm.com>
2015-06-05PCI: xgene: Add APM X-Gene v1 PCIe MSI/MSIX termination driverDuc Dang
APM X-Gene v1 SoC supports its own implementation of MSI, which is not compliant to GIC V2M specification for MSI Termination. There is a single MSI block in X-Gene v1 SOC which serves all 5 PCIe ports. This MSI block supports 2048 MSI termination ports coalesced into 16 physical HW IRQ lines and shared across all 5 PCIe ports. As there are only 16 HW IRQs to serve 2048 MSI vectors, to support set_affinity correctly for each MSI vectors, the 16 HW IRQs are statically allocated to 8 X-Gene v1 cores (2 HW IRQs for each cores). To steer MSI interrupt to target CPU, MSI vector is moved around these HW IRQs lines. With this approach, the total MSI vectors this driver supports is reduced to 256. [bhelgaas: squash doc, driver, maintainer update] Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Tanmay Inamdar <tinamdar@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-05PCI: xgene: Add register offset to config space base addressFeng Kan
In xgene_pcie_map_bus(), we neglected to add in the register offset when calculating the config space address. This means all config accesses operated on the first four bytes of config space. Add the register offset to the config space base address. Also correct the xgene_pcie_map_bus() prototype to fix a compiler warning. [bhelgaas: changelog] Fixes: 350f8be5bb40 ("PCI: xgene: Convert to use generic config accessors") Posting: http://lkml.kernel.org/r/1424214840-26498-1-git-send-email-fkan@apm.com Signed-off-by: Feng Kan <fkan@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Tanmay Inamdar <tinamdar@apm.com> Acked-by: Rob Herring <robh@kernel.org>
2015-02-10Merge tag 'pm+acpi-3.20-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael Wysocki: "We have a few new features this time, including a new SFI-based cpufreq driver, a new devfreq driver for Tegra Activity Monitor, a new devfreq class for providing its governors with raw utilization data and a new ACPI driver for AMD SoCs. Still, the majority of changes here are reworks of existing code to make it more straightforward or to prepare it for implementing new features on top of it. The primary example is the rework of ACPI resources handling from Jiang Liu, Thomas Gleixner and Lv Zheng with support for IOAPIC hotplug implemented on top of it, but there is quite a number of changes of this kind in the cpufreq core, ACPICA, ACPI EC driver, ACPI processor driver and the generic power domains core code too. The most active developer is Viresh Kumar with his cpufreq changes. Specifics: - Rework of the core ACPI resources parsing code to fix issues in it and make using resource offsets more convenient and consolidation of some resource-handing code in a couple of places that have grown analagous data structures and code to cover the the same gap in the core (Jiang Liu, Thomas Gleixner, Lv Zheng). - ACPI-based IOAPIC hotplug support on top of the resources handling rework (Jiang Liu, Yinghai Lu). - ACPICA update to upstream release 20150204 including an interrupt handling rework that allows drivers to install raw handlers for ACPI GPEs which then become entirely responsible for the given GPE and the ACPICA core code won't touch it (Lv Zheng, David E Box, Octavian Purdila). - ACPI EC driver rework to fix several concurrency issues and other problems related to events handling on top of the ACPICA's new support for raw GPE handlers (Lv Zheng). - New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power Subsystem) driver for Intel chips (Ken Xue). - Two minor fixes of the ACPI LPSS driver (Heikki Krogerus, Jarkko Nikula). - Two new blacklist entries for machines (Samsung 730U3E/740U3E and 510R) where the native backlight interface doesn't work correctly while the ACPI one does (Hans de Goede). - Rework of the ACPI processor driver's handling of idle states to make the code more straightforward and less bloated overall (Rafael J Wysocki). - Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht, Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki, Yaowei Bai). - PCI core power management modification to avoid resuming (some) runtime-suspended devices during system suspend if they are in the right states already (Rafael J Wysocki). - New SFI-based cpufreq driver for Intel platforms using SFI (Srinidhi Kasagar). - cpufreq core fixes, cleanups and simplifications (Viresh Kumar, Doug Anderson, Wolfram Sang). - SkyLake CPU support and other updates for the intel_pstate driver (Kristen Carlson Accardi, Srinivas Pandruvada). - cpufreq-dt driver cleanup (Markus Elfring). - Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla). - Generic power domains core code fixes and cleanups (Ulf Hansson). - Operating Performance Points (OPP) core code cleanups and kernel documentation update (Nishanth Menon). - New dabugfs interface to make the list of PM QoS constraints available to user space (Nishanth Menon). - New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso). - New devfreq class (devfreq_event) to provide raw utilization data to devfreq governors (Chanwoo Choi). - Assorted minor fixes and cleanups related to power management (Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist, Pavel Machek, Todd E Brandt, Wonhong Kwon). - turbostat updates (Len Brown) and cpupower Makefile improvement (Sriram Raghunathan)" * tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (151 commits) tools/power turbostat: relax dependency on APERF_MSR tools/power turbostat: relax dependency on invariant TSC Merge branch 'pci/host-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into acpi-resources tools/power turbostat: decode MSR_*_PERF_LIMIT_REASONS tools/power turbostat: relax dependency on root permission ACPI / video: Add disable_native_backlight quirk for Samsung 510R ACPI / PM: Remove unneeded nested #ifdef USB / PM: Remove unneeded #ifdef and associated dead code intel_pstate: provide option to only use intel_pstate with HWP ACPI / EC: Add GPE reference counting debugging messages ACPI / EC: Add query flushing support ACPI / EC: Refine command storm prevention support ACPI / EC: Add command flushing support. ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag ACPI: add AMD ACPI2Platform device support for x86 system ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse() ACPI / EC: Update revision due to raw handler mode. ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp. ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode. ACPICA: Events: Enable APIs to allow interrupt/polling adaptive request based GPE handling model ...
2015-02-05PCI: Use common resource list management code instead of private implementationJiang Liu
Use common resource list management data structure and interfaces instead of private implementation. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-02-02Merge branch 'pci/config' into nextBjorn Helgaas
* pci/config: PCI: xilinx: Convert to use generic config accessors PCI: xgene: Convert to use generic config accessors PCI: tegra: Convert to use generic config accessors PCI: rcar: Convert to use generic config accessors PCI: generic: Convert to use generic config accessors powerpc/powermac: Convert PCI to use generic config accessors powerpc/fsl_pci: Convert PCI to use generic config accessors ARM: ks8695: Convert PCI to use generic config accessors ARM: sa1100: Convert PCI to use generic config accessors ARM: integrator: Convert PCI to use generic config accessors ARM: cns3xxx: Convert PCI to use generic config accessors PCI: Add generic config accessors powerpc/PCI: Add struct pci_ops member names to initialization mn10300/PCI: Add struct pci_ops member names to initialization MIPS: PCI: Add struct pci_ops member names to initialization frv/PCI: Add struct pci_ops member names to initialization
2015-01-30PCI: xgene: Convert to use generic config accessorsRob Herring
Convert the xgene host PCI driver to use the generic config access functions. Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Tanmay Inamdar <tinamdar@apm.com> CC: linux-arm-kernel@lists.infradead.org
2015-01-23PCI: xgene: Include clk.h instead of clk-private.hStephen Boyd
This driver should be including clk.h as it's a clock consumer, not a clock provider that needs to register clocks early. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Tanmay Inamdar <tinamdar@apm.com>
2014-12-14Merge tag 'driver-core-3.19-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev_<level>_once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ...
2014-11-13PCI: xgene: Assign resources to bus before adding new devicesDuc Dang
The X-Gene PCIe driver assumes pci_scan_root_bus() assigns resources as proposed in [1]. But we dropped patch [1] because it would break some architectures, which means the X-Gene PCIe driver is currently broken. Add calls to scan the bus, assign resources, and add devices in the X-Gene driver to fix this. [bhelgaas: changelog] [1] http://lkml.kernel.org/r/1412000971-9242-11-git-send-email-Liviu.Dudau@arm.com Signed-off-by: Duc Dang <dhdang@apm.com> Signed-off-by: Tanmay Inamdar <tinamdar@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-10-20pci: host: drop owner assignment from platform_driversWolfram Sang
A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-01PCI: xgene: Add APM X-Gene PCIe driverTanmay Inamdar
Add the AppliedMicro X-Gene SOC PCIe host controller driver. The X-Gene PCIe controller supports up to 8 lanes and GEN3 speed. The X-Gene SOC supports up to 5 PCIe ports. [bhelgaas: folded in MAINTAINERS and bindings updates] Tested-by: Ming Lei <ming.lei@canonical.com> Tested-by: Dann Frazier <dann.frazier@canonical.com> Signed-off-by: Tanmay Inamdar <tinamdar@apm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com> (driver)