Commit ffe732c2 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'sched/urgent' into sched/core



Merge the latest batch of fixes before applying development patches.
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents 40ea2b42 757dfcaa
......@@ -655,6 +655,11 @@ S: Stanford University
S: Stanford, California 94305
S: USA
N: Carlos Chinea
E: carlos.chinea@nokia.com
E: cch.devel@gmail.com
D: Author of HSI Subsystem
N: Randolph Chung
E: tausq@debian.org
D: Linux/PA-RISC hacker
......
......@@ -196,13 +196,6 @@ chmod 0644 /dev/cpu/microcode
as root before you can use this. You'll probably also want to
get the user-space microcode_ctl utility to use with this.
Powertweak
----------
If you are running v0.1.17 or earlier, you should upgrade to
version v0.99.0 or higher. Running old versions may cause problems
with programs using shared memory.
udev
----
udev is a userspace application for populating /dev dynamically with
......@@ -366,10 +359,6 @@ Intel P6 microcode
------------------
o <http://www.urbanmyth.org/microcode/>
Powertweak
----------
o <http://powertweak.sourceforge.net/>
udev
----
o <http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html>
......
......@@ -58,7 +58,7 @@
</sect1>
<sect1><title>Wait queues and Wake events</title>
!Iinclude/linux/wait.h
!Ekernel/wait.c
!Ekernel/sched/wait.c
</sect1>
<sect1><title>High-resolution timers</title>
!Iinclude/linux/ktime.h
......
......@@ -7,10 +7,18 @@ The MPU contain CPUs, GIC, L2 cache and a local PRCM.
Required properties:
- compatible : Should be "ti,omap3-mpu" for OMAP3
Should be "ti,omap4-mpu" for OMAP4
Should be "ti,omap5-mpu" for OMAP5
- ti,hwmods: "mpu"
Examples:
- For an OMAP5 SMP system:
mpu {
compatible = "ti,omap5-mpu";
ti,hwmods = "mpu"
};
- For an OMAP4 SMP system:
mpu {
......
......@@ -7,6 +7,7 @@ representation in the device tree should be done as under:-
Required properties:
- compatible : should be one of
"arm,armv8-pmuv3"
"arm,cortex-a15-pmu"
"arm,cortex-a9-pmu"
"arm,cortex-a8-pmu"
......
......@@ -49,7 +49,7 @@ adc@12D10000 {
/* NTC thermistor is a hwmon device */
ncp15wb473@0 {
compatible = "ntc,ncp15wb473";
pullup-uV = <1800000>;
pullup-uv = <1800000>;
pullup-ohm = <47000>;
pulldown-ohm = <0>;
io-channels = <&adc 4>;
......
......@@ -6,7 +6,7 @@ SoC's in the Exynos4 family.
Required Properties:
- comptible: should be one of the following.
- compatible: should be one of the following.
- "samsung,exynos4210-clock" - controller compatible with Exynos4210 SoC.
- "samsung,exynos4412-clock" - controller compatible with Exynos4412 SoC.
......
......@@ -5,7 +5,7 @@ controllers within the Exynos5250 SoC.
Required Properties:
- comptible: should be one of the following.
- compatible: should be one of the following.
- "samsung,exynos5250-clock" - controller compatible with Exynos5250 SoC.
- reg: physical base address of the controller and length of memory mapped
......
......@@ -5,7 +5,7 @@ controllers within the Exynos5420 SoC.
Required Properties:
- comptible: should be one of the following.
- compatible: should be one of the following.
- "samsung,exynos5420-clock" - controller compatible with Exynos5420 SoC.
- reg: physical base address of the controller and length of memory mapped
......
......@@ -5,7 +5,7 @@ controllers within the Exynos5440 SoC.
Required Properties:
- comptible: should be "samsung,exynos5440-clock".
- compatible: should be "samsung,exynos5440-clock".
- reg: physical base address of the controller and length of memory mapped
region.
......
......@@ -5,16 +5,42 @@ This is for the non-QE/CPM/GUTs GPIO controllers as found on
Every GPIO controller node must have #gpio-cells property defined,
this information will be used to translate gpio-specifiers.
See bindings/gpio/gpio.txt for details of how to specify GPIO
information for devices.
The GPIO module usually is connected to the SoC's internal interrupt
controller, see bindings/interrupt-controller/interrupts.txt (the
interrupt client nodes section) for details how to specify this GPIO
module's interrupt.
The GPIO module may serve as another interrupt controller (cascaded to
the SoC's internal interrupt controller). See the interrupt controller
nodes section in bindings/interrupt-controller/interrupts.txt for
details.
Required properties:
- compatible : "fsl,<CHIP>-gpio" followed by "fsl,mpc8349-gpio" for
83xx, "fsl,mpc8572-gpio" for 85xx and "fsl,mpc8610-gpio" for 86xx.
- #gpio-cells : Should be two. The first cell is the pin number and the
second cell is used to specify optional parameters (currently unused).
- interrupts : Interrupt mapping for GPIO IRQ.
- interrupt-parent : Phandle for the interrupt controller that
services interrupts for this device.
- gpio-controller : Marks the port as GPIO controller.
- compatible: "fsl,<chip>-gpio" followed by "fsl,mpc8349-gpio"
for 83xx, "fsl,mpc8572-gpio" for 85xx, or
"fsl,mpc8610-gpio" for 86xx.
- #gpio-cells: Should be two. The first cell is the pin number
and the second cell is used to specify optional
parameters (currently unused).
- interrupt-parent: Phandle for the interrupt controller that
services interrupts for this device.
- interrupts: Interrupt mapping for GPIO IRQ.
- gpio-controller: Marks the port as GPIO controller.
Optional properties:
- interrupt-controller: Empty boolean property which marks the GPIO
module as an IRQ controller.
- #interrupt-cells: Should be two. Defines the number of integer
cells required to specify an interrupt within
this interrupt controller. The first cell
defines the pin number, the second cell
defines additional flags (trigger type,
trigger polarity). Note that the available
set of trigger conditions supported by the
GPIO module depends on the actual SoC.
Example of gpio-controller nodes for a MPC8347 SoC:
......@@ -22,39 +48,27 @@ Example of gpio-controller nodes for a MPC8347 SoC:
#gpio-cells = <2>;
compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
reg = <0xc00 0x100>;
interrupts = <74 0x8>;
interrupt-parent = <&ipic>;
interrupts = <74 0x8>;
gpio-controller;
interrupt-controller;
#interrupt-cells = <2>;
};
gpio2: gpio-controller@d00 {
#gpio-cells = <2>;
compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
reg = <0xd00 0x100>;
interrupts = <75 0x8>;
interrupt-parent = <&ipic>;
interrupts = <75 0x8>;
gpio-controller;
};
See booting-without-of.txt for details of how to specify GPIO
information for devices.
To use GPIO pins as interrupt sources for peripherals, specify the
GPIO controller as the interrupt parent and define GPIO number +
trigger mode using the interrupts property, which is defined like
this:
interrupts = <number trigger>, where:
- number: GPIO pin (0..31)
- trigger: trigger mode:
2 = trigger on falling edge
3 = trigger on both edges
Example of device using this is:
Example of a peripheral using the GPIO module as an IRQ controller:
funkyfpga@0 {
compatible = "funky-fpga";
...
interrupts = <4 3>;
interrupt-parent = <&gpio1>;
interrupts = <4 3>;
};
I2C for OMAP platforms
Required properties :
- compatible : Must be "ti,omap3-i2c" or "ti,omap4-i2c"
- compatible : Must be "ti,omap2420-i2c", "ti,omap2430-i2c", "ti,omap3-i2c"
or "ti,omap4-i2c"
- ti,hwmods : Must be "i2c<n>", n being the instance number (1-based)
- #address-cells = <1>;
- #size-cells = <0>;
......
* TI MMC host controller for OMAP1 and 2420
The MMC Host Controller on TI OMAP1 and 2420 family provides
an interface for MMC, SD, and SDIO types of memory cards.
This file documents differences between the core properties described
by mmc.txt and the properties used by the omap mmc driver.
Note that this driver will not work with omap2430 or later omaps,
please see the omap hsmmc driver for the current omaps.
Required properties:
- compatible: Must be "ti,omap2420-mmc", for OMAP2420 controllers
- ti,hwmods: For 2420, must be "msdi<n>", where n is controller
instance starting 1
Examples:
msdi1: mmc@4809c000 {
compatible = "ti,omap2420-mmc";
ti,hwmods = "msdi1";
reg = <0x4809c000 0x80>;
interrupts = <83>;
dmas = <&sdma 61 &sdma 62>;
dma-names = "tx", "rx";
};
* TI MMC host controller for OMAP1 and 2420
The MMC Host Controller on TI OMAP1 and 2420 family provides
an interface for MMC, SD, and SDIO types of memory cards.
This file documents differences between the core properties described
by mmc.txt and the properties used by the omap mmc driver.
Note that this driver will not work with omap2430 or later omaps,
please see the omap hsmmc driver for the current omaps.
Required properties:
- compatible: Must be "ti,omap2420-mmc", for OMAP2420 controllers
- ti,hwmods: For 2420, must be "msdi<n>", where n is controller
instance starting 1
Examples:
msdi1: mmc@4809c000 {
compatible = "ti,omap2420-mmc";
ti,hwmods = "msdi1";
reg = <0x4809c000 0x80>;
interrupts = <83>;
dmas = <&sdma 61 &sdma 62>;
dma-names = "tx", "rx";
};
......@@ -15,6 +15,7 @@ Optional properties:
only if property "phy-reset-gpios" is available. Missing the property
will have the duration be 1 millisecond. Numbers greater than 1000 are
invalid and 1 millisecond will be used instead.
- phy-supply: regulator that powers the Ethernet PHY.
Example:
......@@ -25,4 +26,5 @@ ethernet@83fec000 {
phy-mode = "mii";
phy-reset-gpios = <&gpio2 14 0>; /* GPIO2_14 */
local-mac-address = [00 04 9F 01 1B B9];
phy-supply = <&reg_fec_supply>;
};
NVIDIA Tegra 2 SPI device
Required properties:
- compatible : should be "nvidia,tegra20-spi".
- gpios : should specify GPIOs used for chipselect.
......@@ -32,12 +32,14 @@ est ESTeem Wireless Modems
fsl Freescale Semiconductor
GEFanuc GE Fanuc Intelligent Platforms Embedded Systems, Inc.
gef GE Fanuc Intelligent Platforms Embedded Systems, Inc.
gmt Global Mixed-mode Technology, Inc.
hisilicon Hisilicon Limited.
hp Hewlett Packard
ibm International Business Machines (IBM)
idt Integrated Device Technologies, Inc.
img Imagination Technologies Ltd.
intercontrol Inter Control Group
lg LG Corporation
linux Linux-specific binding
lsi LSI Corp. (LSI Logic)
marvell Marvell Technology Group Ltd.
......
00-INDEX
- This file
gpio.txt
- Introduction to GPIOs and their kernel interfaces
consumer.txt
- How to obtain and use GPIOs in a driver
driver.txt
- How to write a GPIO driver
board.txt
- How to assign GPIOs to a consumer device and a function
sysfs.txt
- Information about the GPIO sysfs interface
gpio-legacy.txt
- Historical documentation of the deprecated GPIO integer interface
GPIO Mappings
=============
This document explains how GPIOs can be assigned to given devices and functions.
Note that it only applies to the new descriptor-based interface. For a
description of the deprecated integer-based GPIO interface please refer to
gpio-legacy.txt (actually, there is no real mapping possible with the old
interface; you just fetch an integer from somewhere and request the
corresponding GPIO.
Platforms that make use of GPIOs must select ARCH_REQUIRE_GPIOLIB (if GPIO usage
is mandatory) or ARCH_WANT_OPTIONAL_GPIOLIB (if GPIO support can be omitted) in
their Kconfig. Then, how GPIOs are mapped depends on what the platform uses to
describe its hardware layout. Currently, mappings can be defined through device
tree, ACPI, and platform data.
Device Tree
-----------
GPIOs can easily be mapped to devices and functions in the device tree. The
exact way to do it depends on the GPIO controller providing the GPIOs, see the
device tree bindings for your controller.
GPIOs mappings are defined in the consumer device's node, in a property named
<function>-gpios, where <function> is the function the driver will request
through gpiod_get(). For example:
foo_device {
compatible = "acme,foo";
...
led-gpios = <&gpio 15 GPIO_ACTIVE_HIGH>, /* red */
<&gpio 16 GPIO_ACTIVE_HIGH>, /* green */
<&gpio 17 GPIO_ACTIVE_HIGH>; /* blue */
power-gpio = <&gpio 1 GPIO_ACTIVE_LOW>;
};
This property will make GPIOs 15, 16 and 17 available to the driver under the
"led" function, and GPIO 1 as the "power" GPIO:
struct gpio_desc *red, *green, *blue, *power;
red = gpiod_get_index(dev, "led", 0);
green = gpiod_get_index(dev, "led", 1);
blue = gpiod_get_index(dev, "led", 2);
power = gpiod_get(dev, "power");
The led GPIOs will be active-high, while the power GPIO will be active-low (i.e.
gpiod_is_active_low(power) will be true).
ACPI
----
ACPI does not support function names for GPIOs. Therefore, only the "idx"
argument of gpiod_get_index() is useful to discriminate between GPIOs assigned
to a device. The "con_id" argument can still be set for debugging purposes (it
will appear under error messages as well as debug and sysfs nodes).
Platform Data
-------------
Finally, GPIOs can be bound to devices and functions using platform data. Board
files that desire to do so need to include the following header:
#include <linux/gpio/driver.h>
GPIOs are mapped by the means of tables of lookups, containing instances of the
gpiod_lookup structure. Two macros are defined to help declaring such mappings:
GPIO_LOOKUP(chip_label, chip_hwnum, dev_id, con_id, flags)
GPIO_LOOKUP_IDX(chip_label, chip_hwnum, dev_id, con_id, idx, flags)
where
- chip_label is the label of the gpiod_chip instance providing the GPIO
- chip_hwnum is the hardware number of the GPIO within the chip
- dev_id is the identifier of the device that will make use of this GPIO. If
NULL, the GPIO will be available to all devices.
- con_id is the name of the GPIO function from the device point of view. It
can be NULL.
- idx is the index of the GPIO within the function.
- flags is defined to specify the following properties:
* GPIOF_ACTIVE_LOW - to configure the GPIO as active-low
* GPIOF_OPEN_DRAIN - GPIO pin is open drain type.
* GPIOF_OPEN_SOURCE - GPIO pin is open source type.
In the future, these flags might be extended to support more properties.
Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0.
A lookup table can then be defined as follows:
struct gpiod_lookup gpios_table[] = {
GPIO_LOOKUP_IDX("gpio.0", 15, "foo.0", "led", 0, GPIO_ACTIVE_HIGH),
GPIO_LOOKUP_IDX("gpio.0", 16, "foo.0", "led", 1, GPIO_ACTIVE_HIGH),
GPIO_LOOKUP_IDX("gpio.0", 17, "foo.0", "led", 2, GPIO_ACTIVE_HIGH),
GPIO_LOOKUP("gpio.0", 1, "foo.0", "power", GPIO_ACTIVE_LOW),
};
And the table can be added by the board code as follows:
gpiod_add_table(gpios_table, ARRAY_SIZE(gpios_table));
The driver controlling "foo.0" will then be able to obtain its GPIOs as follows:
struct gpio_desc *red, *green, *blue, *power;
red = gpiod_get_index(dev, "led", 0);
green = gpiod_get_index(dev, "led", 1);
blue = gpiod_get_index(dev, "led", 2);
power = gpiod_get(dev, "power");
gpiod_direction_output(power, 1);
Since the "power" GPIO is mapped as active-low, its actual signal will be 0
after this code. Contrary to the legacy integer GPIO interface, the active-low
property is handled during mapping and is thus transparent to GPIO consumers.
GPIO Descriptor Consumer Interface
==================================
This document describes the consumer interface of the GPIO framework. Note that
it describes the new descriptor-based interface. For a description of the
deprecated integer-based GPIO interface please refer to gpio-legacy.txt.
Guidelines for GPIOs consumers
==============================
Drivers that can't work without standard GPIO calls should have Kconfig entries
that depend on GPIOLIB. The functions that allow a driver to obtain and use
GPIOs are available by including the following file:
#include <linux/gpio/consumer.h>
All the functions that work with the descriptor-based GPIO interface are
prefixed with gpiod_. The gpio_ prefix is used for the legacy interface. No
other function in the kernel should use these prefixes.
Obtaining and Disposing GPIOs
=============================
With the descriptor-based interface, GPIOs are identified with an opaque,
non-forgeable handler that must be obtained through a call to one of the
gpiod_get() functions. Like many other kernel subsystems, gpiod_get() takes the
device that will use the GPIO and the function the requested GPIO is supposed to
fulfill:
struct gpio_desc *gpiod_get(struct device *dev, const char *con_id)
If a function is implemented by using several GPIOs together (e.g. a simple LED
device that displays digits), an additional index argument can be specified:
struct gpio_desc *gpiod_get_index(struct device *dev,
const char *con_id, unsigned int idx)
Both functions return either a valid GPIO descriptor, or an error code checkable
with IS_ERR(). They will never return a NULL pointer.
Device-managed variants of these functions are also defined:
struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id)
struct gpio_desc *devm_gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx)
A GPIO descriptor can be disposed of using the gpiod_put() function:
void gpiod_put(struct gpio_desc *desc)
It is strictly forbidden to use a descriptor after calling this function. The
device-managed variant is, unsurprisingly:
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
Using GPIOs
===========
Setting Direction
-----------------
The first thing a driver must do with a GPIO is setting its direction. This is
done by invoking one of the gpiod_direction_*() functions:
int gpiod_direction_input(struct gpio_desc *desc)
int gpiod_direction_output(struct gpio_desc *desc, int value)
The return value is zero for success, else a negative errno. It should be
checked, since the get/set calls don't return errors and since misconfiguration
is possible. You should normally issue these calls from a task context. However,
for spinlock-safe GPIOs it is OK to use them before tasking is enabled, as part
of early board setup.
For output GPIOs, the value provided becomes the initial output value. This
helps avoid signal glitching during system startup.
A driver can also query the current direction of a GPIO:
int gpiod_get_direction(const struct gpio_desc *desc)
This function will return either GPIOF_DIR_IN or GPIOF_DIR_OUT.
Be aware that there is no default direction for GPIOs. Therefore, **using a GPIO
without setting its direction first is illegal and will result in undefined
behavior!**
Spinlock-Safe GPIO Access
-------------------------
Most GPIO controllers can be accessed with memory read/write instructions. Those
don't need to sleep, and can safely be done from inside hard (non-threaded) IRQ
handlers and similar contexts.
Use the following calls to access GPIOs from an atomic context:
int gpiod_get_value(const struct gpio_desc *desc);
void gpiod_set_value(struct gpio_desc *desc, int value);
The values are boolean, zero for low, nonzero for high. When reading the value
of an output pin, the value returned should be what's seen on the pin. That
won't always match the specified output value, because of issues including
open-drain signaling and output latencies.
The get/set calls do not return errors because "invalid GPIO" should have been
reported earlier from gpiod_direction_*(). However, note that not all platforms
can read the value of output pins; those that can't should always return zero.
Also, using these calls for GPIOs that can't safely be accessed without sleeping
(see below) is an error.
GPIO Access That May Sleep
--------------------------
Some GPIO controllers must be accessed using message based buses like I2C or
SPI. Commands to read or write those GPIO values require waiting to get to the
head of a queue to transmit a command and get its response. This requires
sleeping, which can't be done from inside IRQ handlers.
Platforms that support this type of GPIO distinguish them from other GPIOs by
returning nonzero from this call:
int gpiod_cansleep(const struct gpio_desc *desc)
To access such GPIOs, a different set of accessors is defined:
int gpiod_get_value_cansleep(const struct gpio_desc *desc)
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
Accessing such GPIOs requires a context which may sleep, for example a threaded
IRQ handler, and those accessors must be used instead of spinlock-safe
accessors without the cansleep() name suffix.
Other than the fact that these accessors might sleep, and will work on GPIOs
that can't be accessed from hardIRQ handlers, these calls act the same as the
spinlock-safe calls.
Active-low State and Raw GPIO Values
------------------------------------
Device drivers like to manage the logical state of a GPIO, i.e. the value their
device will actually receive, no matter what lies between it and the GPIO line.
In some cases, it might make sense to control the actual GPIO line value. The
following set of calls ignore the active-low property of a GPIO and work on the
raw line value:
int gpiod_get_raw_value(const struct gpio_desc *desc)
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
The active-low state of a GPIO can also be queried using the following call: