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authorGrant Likely <grant.likely@secretlab.ca>2012-02-28 13:48:58 -0600
committerGrant Likely <grant.likely@secretlab.ca>2012-02-28 13:48:58 -0600
commitb3950d50cfc343b3e7dc5c69c96a61b182fd1e37 (patch)
treed54affae2b1e25464493b48aa88cd8d6b4770812 /Documentation
parentdaefd89efc279b142bbb054577c2d706da211723 (diff)
parent280ad7fda5f95211857fda38960f2b6fdf6edd3e (diff)
Merge branch 'irqdomain/next' into gpio/next
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/DocBook/device-drivers.tmpl12
-rw-r--r--Documentation/IRQ-domain.txt117
-rw-r--r--Documentation/input/event-codes.txt72
-rw-r--r--Documentation/sysctl/kernel.txt2
4 files changed, 193 insertions, 10 deletions
diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl
index 2f7fd4360848..9c27e5125dd2 100644
--- a/Documentation/DocBook/device-drivers.tmpl
+++ b/Documentation/DocBook/device-drivers.tmpl
@@ -102,9 +102,12 @@ X!Iinclude/linux/kobject.h
!Iinclude/linux/device.h
</sect1>
<sect1><title>Device Drivers Base</title>
+!Idrivers/base/init.c
!Edrivers/base/driver.c
!Edrivers/base/core.c
+!Edrivers/base/syscore.c
!Edrivers/base/class.c
+!Idrivers/base/node.c
!Edrivers/base/firmware_class.c
!Edrivers/base/transport_class.c
<!-- Cannot be included, because
@@ -113,7 +116,7 @@ X!Iinclude/linux/kobject.h
exceed allowed 44 characters maximum
X!Edrivers/base/attribute_container.c
-->
-!Edrivers/base/sys.c
+!Edrivers/base/dd.c
<!--
X!Edrivers/base/interface.c
-->
@@ -121,6 +124,11 @@ X!Edrivers/base/interface.c
!Edrivers/base/platform.c
!Edrivers/base/bus.c
</sect1>
+ <sect1><title>Device Drivers DMA Management</title>
+!Edrivers/base/dma-buf.c
+!Edrivers/base/dma-coherent.c
+!Edrivers/base/dma-mapping.c
+ </sect1>
<sect1><title>Device Drivers Power Management</title>
!Edrivers/base/power/main.c
</sect1>
@@ -219,7 +227,7 @@ X!Isound/sound_firmware.c
<chapter id="uart16x50">
<title>16x50 UART Driver</title>
!Edrivers/tty/serial/serial_core.c
-!Edrivers/tty/serial/8250.c
+!Edrivers/tty/serial/8250/8250.c
</chapter>
<chapter id="fbdev">
diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt
new file mode 100644
index 000000000000..27dcaabfb4db
--- /dev/null
+++ b/Documentation/IRQ-domain.txt
@@ -0,0 +1,117 @@
+irq_domain interrupt number mapping library
+
+The current design of the Linux kernel uses a single large number
+space where each separate IRQ source is assigned a different number.
+This is simple when there is only one interrupt controller, but in
+systems with multiple interrupt controllers the kernel must ensure
+that each one gets assigned non-overlapping allocations of Linux
+IRQ numbers.
+
+The irq_alloc_desc*() and irq_free_desc*() APIs provide allocation of
+irq numbers, but they don't provide any support for reverse mapping of
+the controller-local IRQ (hwirq) number into the Linux IRQ number
+space.
+
+The irq_domain library adds mapping between hwirq and IRQ numbers on
+top of the irq_alloc_desc*() API. An irq_domain to manage mapping is
+preferred over interrupt controller drivers open coding their own
+reverse mapping scheme.
+
+irq_domain also implements translation from Device Tree interrupt
+specifiers to hwirq numbers, and can be easily extended to support
+other IRQ topology data sources.
+
+=== irq_domain usage ===
+An interrupt controller driver creates and registers an irq_domain by
+calling one of the irq_domain_add_*() functions (each mapping method
+has a different allocator function, more on that later). The function
+will return a pointer to the irq_domain on success. The caller must
+provide the allocator function with an irq_domain_ops structure with
+the .map callback populated as a minimum.
+
+In most cases, the irq_domain will begin empty without any mappings
+between hwirq and IRQ numbers. Mappings are added to the irq_domain
+by calling irq_create_mapping() which accepts the irq_domain and a
+hwirq number as arguments. If a mapping for the hwirq doesn't already
+exist then it will allocate a new Linux irq_desc, associate it with
+the hwirq, and call the .map() callback so the driver can perform any
+required hardware setup.
+
+When an interrupt is received, irq_find_mapping() function should
+be used to find the Linux IRQ number from the hwirq number.
+
+If the driver has the Linux IRQ number or the irq_data pointer, and
+needs to know the associated hwirq number (such as in the irq_chip
+callbacks) then it can be directly obtained from irq_data->hwirq.
+
+=== Types of irq_domain mappings ===
+There are several mechanisms available for reverse mapping from hwirq
+to Linux irq, and each mechanism uses a different allocation function.
+Which reverse map type should be used depends on the use case. Each
+of the reverse map types are described below:
+
+==== Linear ====
+irq_domain_add_linear()
+
+The linear reverse map maintains a fixed size table indexed by the
+hwirq number. When a hwirq is mapped, an irq_desc is allocated for
+the hwirq, and the IRQ number is stored in the table.
+
+The Linear map is a good choice when the maximum number of hwirqs is
+fixed and a relatively small number (~ < 256). The advantages of this
+map are fixed time lookup for IRQ numbers, and irq_descs are only
+allocated for in-use IRQs. The disadvantage is that the table must be
+as large as the largest possible hwirq number.
+
+The majority of drivers should use the linear map.
+
+==== Tree ====
+irq_domain_add_tree()
+
+The irq_domain maintains a radix tree map from hwirq numbers to Linux
+IRQs. When an hwirq is mapped, an irq_desc is allocated and the
+hwirq is used as the lookup key for the radix tree.
+
+The tree map is a good choice if the hwirq number can be very large
+since it doesn't need to allocate a table as large as the largest
+hwirq number. The disadvantage is that hwirq to IRQ number lookup is
+dependent on how many entries are in the table.
+
+Very few drivers should need this mapping. At the moment, powerpc
+iseries is the only user.
+
+==== No Map ===-
+irq_domain_add_nomap()
+
+The No Map mapping is to be used when the hwirq number is
+programmable in the hardware. In this case it is best to program the
+Linux IRQ number into the hardware itself so that no mapping is
+required. Calling irq_create_direct_mapping() will allocate a Linux
+IRQ number and call the .map() callback so that driver can program the
+Linux IRQ number into the hardware.
+
+Most drivers cannot use this mapping.
+
+==== Legacy ====
+irq_domain_add_legacy()
+irq_domain_add_legacy_isa()
+
+The Legacy mapping is a special case for drivers that already have a
+range of irq_descs allocated for the hwirqs. It is used when the
+driver cannot be immediately converted to use the linear mapping. For
+example, many embedded system board support files use a set of #defines
+for IRQ numbers that are passed to struct device registrations. In that
+case the Linux IRQ numbers cannot be dynamically assigned and the legacy
+mapping should be used.
+
+The legacy map assumes a contiguous range of IRQ numbers has already
+been allocated for the controller and that the IRQ number can be
+calculated by adding a fixed offset to the hwirq number, and
+visa-versa. The disadvantage is that it requires the interrupt
+controller to manage IRQ allocations and it requires an irq_desc to be
+allocated for every hwirq, even if it is unused.
+
+The legacy map should only be used if fixed IRQ mappings must be
+supported. For example, ISA controllers would use the legacy map for
+mapping Linux IRQs 0-15 so that existing ISA drivers get the correct IRQ
+numbers.
diff --git a/Documentation/input/event-codes.txt b/Documentation/input/event-codes.txt
index 23fcb05175be..53305bd08182 100644
--- a/Documentation/input/event-codes.txt
+++ b/Documentation/input/event-codes.txt
@@ -17,11 +17,11 @@ reports supported by a device are also provided by sysfs in
class/input/event*/device/capabilities/, and the properties of a device are
provided in class/input/event*/device/properties.
-Types:
-==========
-Types are groupings of codes under a logical input construct. Each type has a
-set of applicable codes to be used in generating events. See the Codes section
-for details on valid codes for each type.
+Event types:
+===========
+Event types are groupings of codes under a logical input construct. Each
+type has a set of applicable codes to be used in generating events. See the
+Codes section for details on valid codes for each type.
* EV_SYN:
- Used as markers to separate events. Events may be separated in time or in
@@ -63,9 +63,9 @@ for details on valid codes for each type.
* EV_FF_STATUS:
- Used to receive force feedback device status.
-Codes:
-==========
-Codes define the precise type of event.
+Event codes:
+===========
+Event codes define the precise type of event.
EV_SYN:
----------
@@ -220,6 +220,56 @@ EV_PWR:
EV_PWR events are a special type of event used specifically for power
mangement. Its usage is not well defined. To be addressed later.
+Device properties:
+=================
+Normally, userspace sets up an input device based on the data it emits,
+i.e., the event types. In the case of two devices emitting the same event
+types, additional information can be provided in the form of device
+properties.
+
+INPUT_PROP_DIRECT + INPUT_PROP_POINTER:
+--------------------------------------
+The INPUT_PROP_DIRECT property indicates that device coordinates should be
+directly mapped to screen coordinates (not taking into account trivial
+transformations, such as scaling, flipping and rotating). Non-direct input
+devices require non-trivial transformation, such as absolute to relative
+transformation for touchpads. Typical direct input devices: touchscreens,
+drawing tablets; non-direct devices: touchpads, mice.
+
+The INPUT_PROP_POINTER property indicates that the device is not transposed
+on the screen and thus requires use of an on-screen pointer to trace user's
+movements. Typical pointer devices: touchpads, tablets, mice; non-pointer
+device: touchscreen.
+
+If neither INPUT_PROP_DIRECT or INPUT_PROP_POINTER are set, the property is
+considered undefined and the device type should be deduced in the
+traditional way, using emitted event types.
+
+INPUT_PROP_BUTTONPAD:
+--------------------
+For touchpads where the button is placed beneath the surface, such that
+pressing down on the pad causes a button click, this property should be
+set. Common in clickpad notebooks and macbooks from 2009 and onwards.
+
+Originally, the buttonpad property was coded into the bcm5974 driver
+version field under the name integrated button. For backwards
+compatibility, both methods need to be checked in userspace.
+
+INPUT_PROP_SEMI_MT:
+------------------
+Some touchpads, most common between 2008 and 2011, can detect the presence
+of multiple contacts without resolving the individual positions; only the
+number of contacts and a rectangular shape is known. For such
+touchpads, the semi-mt property should be set.
+
+Depending on the device, the rectangle may enclose all touches, like a
+bounding box, or just some of them, for instance the two most recent
+touches. The diversity makes the rectangle of limited use, but some
+gestures can normally be extracted from it.
+
+If INPUT_PROP_SEMI_MT is not set, the device is assumed to be a true MT
+device.
+
Guidelines:
==========
The guidelines below ensure proper single-touch and multi-finger functionality.
@@ -240,6 +290,8 @@ used to report when a touch is active on the screen.
BTN_{MOUSE,LEFT,MIDDLE,RIGHT} must not be reported as the result of touch
contact. BTN_TOOL_<name> events should be reported where possible.
+For new hardware, INPUT_PROP_DIRECT should be set.
+
Trackpads:
----------
Legacy trackpads that only provide relative position information must report
@@ -250,6 +302,8 @@ location of the touch. BTN_TOUCH should be used to report when a touch is active
on the trackpad. Where multi-finger support is available, BTN_TOOL_<name> should
be used to report the number of touches active on the trackpad.
+For new hardware, INPUT_PROP_POINTER should be set.
+
Tablets:
----------
BTN_TOOL_<name> events must be reported when a stylus or other tool is active on
@@ -260,3 +314,5 @@ button may be used for buttons on the tablet except BTN_{MOUSE,LEFT}.
BTN_{0,1,2,etc} are good generic codes for unlabeled buttons. Do not use
meaningful buttons, like BTN_FORWARD, unless the button is labeled for that
purpose on the device.
+
+For new hardware, both INPUT_PROP_DIRECT and INPUT_PROP_POINTER should be set.
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 8c20fbd8b42d..6d78841fd416 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -601,6 +601,8 @@ can be ORed together:
instead of using the one provided by the hardware.
512 - A kernel warning has occurred.
1024 - A module from drivers/staging was loaded.
+2048 - The system is working around a severe firmware bug.
+4096 - An out-of-tree module has been loaded.
==============================================================