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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-14 20:21:54 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-14 20:21:54 -0700 |
commit | 2481bc75283ea10e75d5fb1a8b42af363fc4b45c (patch) | |
tree | 42dd659a23041a08955aceebab859b616164c2f6 /arch/arm/kernel/cpuidle.c | |
parent | 8691c130fae136bb2b7d0554422a2dff4c6ac169 (diff) | |
parent | 518b4e272d99dcb13699b229ea480bc845c141f6 (diff) | |
download | op-kernel-dev-2481bc75283ea10e75d5fb1a8b42af363fc4b45c.zip op-kernel-dev-2481bc75283ea10e75d5fb1a8b42af363fc4b45c.tar.gz |
Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
"These are mostly fixes and cleanups all over, although there are a few
items that sort of fall into the new feature category.
First off, we have new callbacks for PM domains that should help us to
handle some issues related to device initialization in a better way.
There also is some consolidation in the unified device properties API
area allowing us to use that inferface for accessing data coming from
platform initialization code in addition to firmware-provided data.
We have some new device/CPU IDs in a few drivers, support for new
chips and a new cpufreq driver too.
Specifics:
- Generic PM domains support update including new PM domain callbacks
to handle device initialization better (Russell King, Rafael J
Wysocki, Kevin Hilman)
- Unified device properties API update including a new mechanism for
accessing data provided by platform initialization code (Rafael J
Wysocki, Adrian Hunter)
- ARM cpuidle update including ARM32/ARM64 handling consolidation
(Daniel Lezcano)
- intel_idle update including support for the Silvermont Core in the
Baytrail SOC and for the Airmont Core in the Cherrytrail and
Braswell SOCs (Len Brown, Mathias Krause)
- New cpufreq driver for Hisilicon ACPU (Leo Yan)
- intel_pstate update including support for the Knights Landing chip
(Dasaratharaman Chandramouli, Kristen Carlson Accardi)
- QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)
- powernv cpufreq driver update (Shilpasri G Bhat)
- devfreq update including Tegra support changes (Tomeu Vizoso,
MyungJoo Ham, Chanwoo Choi)
- powercap RAPL (Running-Average Power Limit) driver update including
support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)
- ACPI device enumeration update related to the handling of the
special PRP0001 device ID allowing DT-style 'compatible' property
to be used for ACPI device identification (Rafael J Wysocki)
- ACPI EC driver update including limited _DEP support (Lan Tianyu,
Lv Zheng)
- ACPI backlight driver update including a new mechanism to allow
native backlight handling to be forced on non-Windows 8 systems and
a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)
- New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)
- Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)
- Fixes related to suspend-to-idle for the iTCO watchdog driver and
the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)
- PM tracing support for the suspend phase of system suspend/resume
transitions (Zhonghui Fu)
- Configurable delay for the system suspend/resume testing facility
(Brian Norris)
- PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"
* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
ACPI / scan: Rework modalias creation when "compatible" is present
intel_idle: mark cpu id array as __initconst
powercap / RAPL: mark rapl_ids array as __initconst
powercap / RAPL: add ID for Broadwell server
intel_pstate: Knights Landing support
intel_pstate: remove MSR test
cpufreq: fix qoriq uniprocessor build
ACPI / scan: Take the PRP0001 position in the list of IDs into account
ACPI / scan: Simplify acpi_match_device()
ACPI / scan: Generalize of_compatible matching
device property: Introduce firmware node type for platform data
device property: Make it possible to use secondary firmware nodes
PM / watchdog: iTCO: stop watchdog during system suspend
cpufreq: hisilicon: add acpu driver
ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
cpufreq: powernv: Report cpu frequency throttling
intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
intel_idle: Update support for Silvermont Core in Baytrail SOC
PM / devfreq: tegra: Register governor on module init
...
Diffstat (limited to 'arch/arm/kernel/cpuidle.c')
-rw-r--r-- | arch/arm/kernel/cpuidle.c | 133 |
1 files changed, 132 insertions, 1 deletions
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c index 89545f6..318da33 100644 --- a/arch/arm/kernel/cpuidle.c +++ b/arch/arm/kernel/cpuidle.c @@ -10,8 +10,28 @@ */ #include <linux/cpuidle.h> -#include <asm/proc-fns.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <asm/cpuidle.h> +extern struct of_cpuidle_method __cpuidle_method_of_table[]; + +static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel + __used __section(__cpuidle_method_of_table_end); + +static struct cpuidle_ops cpuidle_ops[NR_CPUS]; + +/** + * arm_cpuidle_simple_enter() - a wrapper to cpu_do_idle() + * @dev: not used + * @drv: not used + * @index: not used + * + * A trivial wrapper to allow the cpu_do_idle function to be assigned as a + * cpuidle callback by matching the function signature. + * + * Returns the index passed as parameter + */ int arm_cpuidle_simple_enter(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { @@ -19,3 +39,114 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev, return index; } + +/** + * arm_cpuidle_suspend() - function to enter low power idle states + * @index: an integer used as an identifier for the low level PM callbacks + * + * This function calls the underlying arch specific low level PM code as + * registered at the init time. + * + * Returns -EOPNOTSUPP if no suspend callback is defined, the result of the + * callback otherwise. + */ +int arm_cpuidle_suspend(int index) +{ + int ret = -EOPNOTSUPP; + int cpu = smp_processor_id(); + + if (cpuidle_ops[cpu].suspend) + ret = cpuidle_ops[cpu].suspend(cpu, index); + + return ret; +} + +/** + * arm_cpuidle_get_ops() - find a registered cpuidle_ops by name + * @method: the method name + * + * Search in the __cpuidle_method_of_table array the cpuidle ops matching the + * method name. + * + * Returns a struct cpuidle_ops pointer, NULL if not found. + */ +static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method) +{ + struct of_cpuidle_method *m = __cpuidle_method_of_table; + + for (; m->method; m++) + if (!strcmp(m->method, method)) + return m->ops; + + return NULL; +} + +/** + * arm_cpuidle_read_ops() - Initialize the cpuidle ops with the device tree + * @dn: a pointer to a struct device node corresponding to a cpu node + * @cpu: the cpu identifier + * + * Get the method name defined in the 'enable-method' property, retrieve the + * associated cpuidle_ops and do a struct copy. This copy is needed because all + * cpuidle_ops are tagged __initdata and will be unloaded after the init + * process. + * + * Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if + * no cpuidle_ops is registered for the 'enable-method'. + */ +static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu) +{ + const char *enable_method; + struct cpuidle_ops *ops; + + enable_method = of_get_property(dn, "enable-method", NULL); + if (!enable_method) + return -ENOENT; + + ops = arm_cpuidle_get_ops(enable_method); + if (!ops) { + pr_warn("%s: unsupported enable-method property: %s\n", + dn->full_name, enable_method); + return -EOPNOTSUPP; + } + + cpuidle_ops[cpu] = *ops; /* structure copy */ + + pr_notice("cpuidle: enable-method property '%s'" + " found operations\n", enable_method); + + return 0; +} + +/** + * arm_cpuidle_init() - Initialize cpuidle_ops for a specific cpu + * @cpu: the cpu to be initialized + * + * Initialize the cpuidle ops with the device for the cpu and then call + * the cpu's idle initialization callback. This may fail if the underlying HW + * is not operational. + * + * Returns: + * 0 on success, + * -ENODEV if it fails to find the cpu node in the device tree, + * -EOPNOTSUPP if it does not find a registered cpuidle_ops for this cpu, + * -ENOENT if it fails to find an 'enable-method' property, + * -ENXIO if the HW reports a failure or a misconfiguration, + * -ENOMEM if the HW report an memory allocation failure + */ +int __init arm_cpuidle_init(int cpu) +{ + struct device_node *cpu_node = of_cpu_device_node_get(cpu); + int ret; + + if (!cpu_node) + return -ENODEV; + + ret = arm_cpuidle_read_ops(cpu_node, cpu); + if (!ret && cpuidle_ops[cpu].init) + ret = cpuidle_ops[cpu].init(cpu_node, cpu); + + of_node_put(cpu_node); + + return ret; +} |