diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/acpi/enumeration.txt | 26 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 7 | ||||
| -rw-r--r-- | Documentation/power/basic-pm-debugging.txt | 10 |
3 files changed, 36 insertions, 7 deletions
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt index 9b121a569ab4..750401f91341 100644 --- a/Documentation/acpi/enumeration.txt +++ b/Documentation/acpi/enumeration.txt @@ -254,8 +254,13 @@ GPIO support ~~~~~~~~~~~~ ACPI 5 introduced two new resources to describe GPIO connections: GpioIo and GpioInt. These resources are used be used to pass GPIO numbers used by -the device to the driver. For example: +the device to the driver. ACPI 5.1 extended this with _DSD (Device +Specific Data) which made it possible to name the GPIOs among other things. +For example: + +Device (DEV) +{ Method (_CRS, 0, NotSerialized) { Name (SBUF, ResourceTemplate() @@ -285,6 +290,18 @@ the device to the driver. For example: Return (SBUF) } + // ACPI 5.1 _DSD used for naming the GPIOs + Name (_DSD, Package () + { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () + { + Package () {"power-gpios", Package() {^DEV, 0, 0, 0 }}, + Package () {"irq-gpios", Package() {^DEV, 1, 0, 0 }}, + } + }) + ... + These GPIO numbers are controller relative and path "\\_SB.PCI0.GPI0" specifies the path to the controller. In order to use these GPIOs in Linux we need to translate them to the corresponding Linux GPIO descriptors. @@ -300,11 +317,11 @@ a code like this: struct gpio_desc *irq_desc, *power_desc; - irq_desc = gpiod_get_index(dev, NULL, 1); + irq_desc = gpiod_get(dev, "irq"); if (IS_ERR(irq_desc)) /* handle error */ - power_desc = gpiod_get_index(dev, NULL, 0); + power_desc = gpiod_get(dev, "power"); if (IS_ERR(power_desc)) /* handle error */ @@ -313,6 +330,9 @@ a code like this: There are also devm_* versions of these functions which release the descriptors once the device is released. +See Documentation/acpi/gpio-properties.txt for more information about the +_DSD binding related to GPIOs. + MFD devices ~~~~~~~~~~~ The MFD devices register their children as platform devices. For the child diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 327556349757..491bbd104b06 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3477,6 +3477,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. improve throughput, but will also increase the amount of memory reserved for use by the client. + suspend.pm_test_delay= + [SUSPEND] + Sets the number of seconds to remain in a suspend test + mode before resuming the system (see + /sys/power/pm_test). Only available when CONFIG_PM_DEBUG + is set. Default value is 5. + swapaccount=[0|1] [KNL] Enable accounting of swap in memory resource controller if no parameter or 1 is given or disable diff --git a/Documentation/power/basic-pm-debugging.txt b/Documentation/power/basic-pm-debugging.txt index edeecd447d23..b96098ccfe69 100644 --- a/Documentation/power/basic-pm-debugging.txt +++ b/Documentation/power/basic-pm-debugging.txt @@ -75,12 +75,14 @@ you should do the following: # echo platform > /sys/power/disk # echo disk > /sys/power/state -Then, the kernel will try to freeze processes, suspend devices, wait 5 seconds, -resume devices and thaw processes. If "platform" is written to +Then, the kernel will try to freeze processes, suspend devices, wait a few +seconds (5 by default, but configurable by the suspend.pm_test_delay module +parameter), resume devices and thaw processes. If "platform" is written to /sys/power/pm_test , then after suspending devices the kernel will additionally invoke the global control methods (eg. ACPI global control methods) used to -prepare the platform firmware for hibernation. Next, it will wait 5 seconds and -invoke the platform (eg. ACPI) global methods used to cancel hibernation etc. +prepare the platform firmware for hibernation. Next, it will wait a +configurable number of seconds and invoke the platform (eg. ACPI) global +methods used to cancel hibernation etc. Writing "none" to /sys/power/pm_test causes the kernel to switch to the normal hibernation/suspend operations. Also, when open for reading, /sys/power/pm_test |