diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/arm/exynos/power_domain.txt | 13 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/cpufreq/cpufreq-dt.txt (renamed from Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt) | 8 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/power/power_domain.txt | 49 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/power/rockchip-io-domain.txt | 83 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 10 | ||||
| -rw-r--r-- | Documentation/power/suspend-and-interrupts.txt | 123 |
6 files changed, 271 insertions, 15 deletions
diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt index 8b4f7b7fe88b..abde1ea8a119 100644 --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt @@ -8,6 +8,8 @@ Required Properties: * samsung,exynos4210-pd - for exynos4210 type power domain. - reg: physical base address of the controller and length of memory mapped region. +- #power-domain-cells: number of cells in power domain specifier; + must be 0. Optional Properties: - clocks: List of clock handles. The parent clocks of the input clocks to the @@ -29,6 +31,7 @@ Example: lcd0: power-domain-lcd0 { compatible = "samsung,exynos4210-pd"; reg = <0x10023C00 0x10>; + #power-domain-cells = <0>; }; mfc_pd: power-domain@10044060 { @@ -37,12 +40,8 @@ Example: clocks = <&clock CLK_FIN_PLL>, <&clock CLK_MOUT_SW_ACLK333>, <&clock CLK_MOUT_USER_ACLK333>; clock-names = "oscclk", "pclk0", "clk0"; + #power-domain-cells = <0>; }; -Example of the node using power domain: - - node { - /* ... */ - samsung,power-domain = <&lcd0>; - /* ... */ - }; +See Documentation/devicetree/bindings/power/power_domain.txt for description +of consumer-side bindings. diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-dt.txt index 366690cb86a3..e41c98ffbccb 100644 --- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-dt.txt @@ -1,8 +1,8 @@ -Generic CPU0 cpufreq driver +Generic cpufreq driver -It is a generic cpufreq driver for CPU0 frequency management. It -supports both uniprocessor (UP) and symmetric multiprocessor (SMP) -systems which share clock and voltage across all CPUs. +It is a generic DT based cpufreq driver for frequency management. It supports +both uniprocessor (UP) and symmetric multiprocessor (SMP) systems which share +clock and voltage across all CPUs. Both required and optional properties listed below must be defined under node /cpus/cpu@0. diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt new file mode 100644 index 000000000000..98c16672ab5f --- /dev/null +++ b/Documentation/devicetree/bindings/power/power_domain.txt @@ -0,0 +1,49 @@ +* Generic PM domains + +System on chip designs are often divided into multiple PM domains that can be +used for power gating of selected IP blocks for power saving by reduced leakage +current. + +This device tree binding can be used to bind PM domain consumer devices with +their PM domains provided by PM domain providers. A PM domain provider can be +represented by any node in the device tree and can provide one or more PM +domains. A consumer node can refer to the provider by a phandle and a set of +phandle arguments (so called PM domain specifiers) of length specified by the +#power-domain-cells property in the PM domain provider node. + +==PM domain providers== + +Required properties: + - #power-domain-cells : Number of cells in a PM domain specifier; + Typically 0 for nodes representing a single PM domain and 1 for nodes + providing multiple PM domains (e.g. power controllers), but can be any value + as specified by device tree binding documentation of particular provider. + +Example: + + power: power-controller@12340000 { + compatible = "foo,power-controller"; + reg = <0x12340000 0x1000>; + #power-domain-cells = <1>; + }; + +The node above defines a power controller that is a PM domain provider and +expects one cell as its phandle argument. + +==PM domain consumers== + +Required properties: + - power-domains : A phandle and PM domain specifier as defined by bindings of + the power controller specified by phandle. + +Example: + + leaky-device@12350000 { + compatible = "foo,i-leak-current"; + reg = <0x12350000 0x1000>; + power-domains = <&power 0>; + }; + +The node above defines a typical PM domain consumer device, which is located +inside a PM domain with index 0 of a power controller represented by a node +with the label "power". diff --git a/Documentation/devicetree/bindings/power/rockchip-io-domain.txt b/Documentation/devicetree/bindings/power/rockchip-io-domain.txt new file mode 100644 index 000000000000..6fbf6e7ecde6 --- /dev/null +++ b/Documentation/devicetree/bindings/power/rockchip-io-domain.txt @@ -0,0 +1,83 @@ +Rockchip SRAM for IO Voltage Domains: +------------------------------------- + +IO domain voltages on some Rockchip SoCs are variable but need to be +kept in sync between the regulators and the SoC using a special +register. + +A specific example using rk3288: +- If the regulator hooked up to a pin like SDMMC0_VDD is 3.3V then + bit 7 of GRF_IO_VSEL needs to be 0. If the regulator hooked up to + that same pin is 1.8V then bit 7 of GRF_IO_VSEL needs to be 1. + +Said another way, this driver simply handles keeping bits in the SoC's +general register file (GRF) in sync with the actual value of a voltage +hooked up to the pins. + +Note that this driver specifically doesn't include: +- any logic for deciding what voltage we should set regulators to +- any logic for deciding whether regulators (or internal SoC blocks) + should have power or not have power + +If there were some other software that had the smarts of making +decisions about regulators, it would work in conjunction with this +driver. When that other software adjusted a regulator's voltage then +this driver would handle telling the SoC about it. A good example is +vqmmc for SD. In that case the dw_mmc driver simply is told about a +regulator. It changes the regulator between 3.3V and 1.8V at the +right time. This driver notices the change and makes sure that the +SoC is on the same page. + + +Required properties: +- compatible: should be one of: + - "rockchip,rk3188-io-voltage-domain" for rk3188 + - "rockchip,rk3288-io-voltage-domain" for rk3288 +- rockchip,grf: phandle to the syscon managing the "general register files" + + +You specify supplies using the standard regulator bindings by including +a phandle the the relevant regulator. All specified supplies must be able +to report their voltage. The IO Voltage Domain for any non-specified +supplies will be not be touched. + +Possible supplies for rk3188: +- ap0-supply: The supply connected to AP0_VCC. +- ap1-supply: The supply connected to AP1_VCC. +- cif-supply: The supply connected to CIF_VCC. +- flash-supply: The supply connected to FLASH_VCC. +- lcdc0-supply: The supply connected to LCD0_VCC. +- lcdc1-supply: The supply connected to LCD1_VCC. +- vccio0-supply: The supply connected to VCCIO0. +- vccio1-supply: The supply connected to VCCIO1. + Sometimes also labeled VCCIO1 and VCCIO2. + +Possible supplies for rk3288: +- audio-supply: The supply connected to APIO4_VDD. +- bb-supply: The supply connected to APIO5_VDD. +- dvp-supply: The supply connected to DVPIO_VDD. +- flash0-supply: The supply connected to FLASH0_VDD. Typically for eMMC +- flash1-supply: The supply connected to FLASH1_VDD. Also known as SDIO1. +- gpio30-supply: The supply connected to APIO1_VDD. +- gpio1830 The supply connected to APIO2_VDD. +- lcdc-supply: The supply connected to LCDC_VDD. +- sdcard-supply: The supply connected to SDMMC0_VDD. +- wifi-supply: The supply connected to APIO3_VDD. Also known as SDIO0. + + +Example: + + io-domains { + compatible = "rockchip,rk3288-io-voltage-domain"; + rockchip,grf = <&grf>; + + audio-supply = <&vcc18_codec>; + bb-supply = <&vcc33_io>; + dvp-supply = <&vcc_18>; + flash0-supply = <&vcc18_flashio>; + gpio1830-supply = <&vcc33_io>; + gpio30-supply = <&vcc33_pmuio>; + lcdc-supply = <&vcc33_lcd>; + sdcard-supply = <&vccio_sd>; + wifi-supply = <&vcc18_wl>; + }; diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d9a452e8fb9b..cc4ab2517abc 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3321,11 +3321,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. tdfx= [HW,DRM] - test_suspend= [SUSPEND] + test_suspend= [SUSPEND][,N] Specify "mem" (for Suspend-to-RAM) or "standby" (for - standby suspend) as the system sleep state to briefly - enter during system startup. The system is woken from - this state using a wakeup-capable RTC alarm. + standby suspend) or "freeze" (for suspend type freeze) + as the system sleep state during system startup with + the optional capability to repeat N number of times. + The system is woken from this state using a + wakeup-capable RTC alarm. thash_entries= [KNL,NET] Set number of hash buckets for TCP connection diff --git a/Documentation/power/suspend-and-interrupts.txt b/Documentation/power/suspend-and-interrupts.txt new file mode 100644 index 000000000000..69663640dea5 --- /dev/null +++ b/Documentation/power/suspend-and-interrupts.txt @@ -0,0 +1,123 @@ +System Suspend and Device Interrupts + +Copyright (C) 2014 Intel Corp. +Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> + + +Suspending and Resuming Device IRQs +----------------------------------- + +Device interrupt request lines (IRQs) are generally disabled during system +suspend after the "late" phase of suspending devices (that is, after all of the +->prepare, ->suspend and ->suspend_late callbacks have been executed for all +devices). That is done by suspend_device_irqs(). + +The rationale for doing so is that after the "late" phase of device suspend +there is no legitimate reason why any interrupts from suspended devices should +trigger and if any devices have not been suspended properly yet, it is better to +block interrupts from them anyway. Also, in the past we had problems with +interrupt handlers for shared IRQs that device drivers implementing them were +not prepared for interrupts triggering after their devices had been suspended. +In some cases they would attempt to access, for example, memory address spaces +of suspended devices and cause unpredictable behavior to ensue as a result. +Unfortunately, such problems are very difficult to debug and the introduction +of suspend_device_irqs(), along with the "noirq" phase of device suspend and +resume, was the only practical way to mitigate them. + +Device IRQs are re-enabled during system resume, right before the "early" phase +of resuming devices (that is, before starting to execute ->resume_early +callbacks for devices). The function doing that is resume_device_irqs(). + + +The IRQF_NO_SUSPEND Flag +------------------------ + +There are interrupts that can legitimately trigger during the entire system +suspend-resume cycle, including the "noirq" phases of suspending and resuming +devices as well as during the time when nonboot CPUs are taken offline and +brought back online. That applies to timer interrupts in the first place, +but also to IPIs and to some other special-purpose interrupts. + +The IRQF_NO_SUSPEND flag is used to indicate that to the IRQ subsystem when +requesting a special-purpose interrupt. It causes suspend_device_irqs() to +leave the corresponding IRQ enabled so as to allow the interrupt to work all +the time as expected. + +Note that the IRQF_NO_SUSPEND flag affects the entire IRQ and not just one +user of it. Thus, if the IRQ is shared, all of the interrupt handlers installed +for it will be executed as usual after suspend_device_irqs(), even if the +IRQF_NO_SUSPEND flag was not passed to request_irq() (or equivalent) by some of +the IRQ's users. For this reason, using IRQF_NO_SUSPEND and IRQF_SHARED at the +same time should be avoided. + + +System Wakeup Interrupts, enable_irq_wake() and disable_irq_wake() +------------------------------------------------------------------ + +System wakeup interrupts generally need to be configured to wake up the system +from sleep states, especially if they are used for different purposes (e.g. as +I/O interrupts) in the working state. + +That may involve turning on a special signal handling logic within the platform +(such as an SoC) so that signals from a given line are routed in a different way +during system sleep so as to trigger a system wakeup when needed. For example, +the platform may include a dedicated interrupt controller used specifically for +handling system wakeup events. Then, if a given interrupt line is supposed to +wake up the system from sleep sates, the corresponding input of that interrupt +controller needs to be enabled to receive signals from the line in question. +After wakeup, it generally is better to disable that input to prevent the +dedicated controller from triggering interrupts unnecessarily. + +The IRQ subsystem provides two helper functions to be used by device drivers for +those purposes. Namely, enable_irq_wake() turns on the platform's logic for +handling the given IRQ as a system wakeup interrupt line and disable_irq_wake() +turns that logic off. + +Calling enable_irq_wake() causes suspend_device_irqs() to treat the given IRQ +in a special way. Namely, the IRQ remains enabled, by on the first interrupt +it will be disabled, marked as pending and "suspended" so that it will be +re-enabled by resume_device_irqs() during the subsequent system resume. Also +the PM core is notified about the event which casues the system suspend in +progress to be aborted (that doesn't have to happen immediately, but at one +of the points where the suspend thread looks for pending wakeup events). + +This way every interrupt from a wakeup interrupt source will either cause the +system suspend currently in progress to be aborted or wake up the system if +already suspended. However, after suspend_device_irqs() interrupt handlers are +not executed for system wakeup IRQs. They are only executed for IRQF_NO_SUSPEND +IRQs at that time, but those IRQs should not be configured for system wakeup +using enable_irq_wake(). + + +Interrupts and Suspend-to-Idle +------------------------------ + +Suspend-to-idle (also known as the "freeze" sleep state) is a relatively new +system sleep state that works by idling all of the processors and waiting for +interrupts right after the "noirq" phase of suspending devices. + +Of course, this means that all of the interrupts with the IRQF_NO_SUSPEND flag +set will bring CPUs out of idle while in that state, but they will not cause the +IRQ subsystem to trigger a system wakeup. + +System wakeup interrupts, in turn, will trigger wakeup from suspend-to-idle in +analogy with what they do in the full system suspend case. The only difference +is that the wakeup from suspend-to-idle is signaled using the usual working +state interrupt delivery mechanisms and doesn't require the platform to use +any special interrupt handling logic for it to work. + + +IRQF_NO_SUSPEND and enable_irq_wake() +------------------------------------- + +There are no valid reasons to use both enable_irq_wake() and the IRQF_NO_SUSPEND +flag on the same IRQ. + +First of all, if the IRQ is not shared, the rules for handling IRQF_NO_SUSPEND +interrupts (interrupt handlers are invoked after suspend_device_irqs()) are +directly at odds with the rules for handling system wakeup interrupts (interrupt +handlers are not invoked after suspend_device_irqs()). + +Second, both enable_irq_wake() and IRQF_NO_SUSPEND apply to entire IRQs and not +to individual interrupt handlers, so sharing an IRQ between a system wakeup +interrupt source and an IRQF_NO_SUSPEND interrupt source does not make sense. |
