docs: split up the driver book

We don't need to keep it as a single large file anymore; split it up so
that it is easier to manage and the individual sections can be read
directly as plain files.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

11 files changed, 676 insertions, 655 deletions

diff --git a/Documentation/driver-api/basics.rst b/Documentation/driver-api/basics.rst
new file mode 100644
index 000000000000..935b9b8d456c
--- /dev/null
+++ b/Documentation/driver-api/basics.rst
@@ -0,0 +1,120 @@
+Driver Basics
+=============
+
+Driver Entry and Exit points
+----------------------------
+
+.. kernel-doc:: include/linux/init.h
+   :internal:
+
+Atomic and pointer manipulation
+-------------------------------
+
+.. kernel-doc:: arch/x86/include/asm/atomic.h
+   :internal:
+
+Delaying, scheduling, and timer routines
+----------------------------------------
+
+.. kernel-doc:: include/linux/sched.h
+   :internal:
+
+.. kernel-doc:: kernel/sched/core.c
+   :export:
+
+.. kernel-doc:: kernel/sched/cpupri.c
+   :internal:
+
+.. kernel-doc:: kernel/sched/fair.c
+   :internal:
+
+.. kernel-doc:: include/linux/completion.h
+   :internal:
+
+.. kernel-doc:: kernel/time/timer.c
+   :export:
+
+Wait queues and Wake events
+---------------------------
+
+.. kernel-doc:: include/linux/wait.h
+   :internal:
+
+.. kernel-doc:: kernel/sched/wait.c
+   :export:
+
+High-resolution timers
+----------------------
+
+.. kernel-doc:: include/linux/ktime.h
+   :internal:
+
+.. kernel-doc:: include/linux/hrtimer.h
+   :internal:
+
+.. kernel-doc:: kernel/time/hrtimer.c
+   :export:
+
+Workqueues and Kevents
+----------------------
+
+.. kernel-doc:: include/linux/workqueue.h
+   :internal:
+
+.. kernel-doc:: kernel/workqueue.c
+   :export:
+
+Internal Functions
+------------------
+
+.. kernel-doc:: kernel/exit.c
+   :internal:
+
+.. kernel-doc:: kernel/signal.c
+   :internal:
+
+.. kernel-doc:: include/linux/kthread.h
+   :internal:
+
+.. kernel-doc:: kernel/kthread.c
+   :export:
+
+Kernel objects manipulation
+---------------------------
+
+.. kernel-doc:: lib/kobject.c
+   :export:
+
+Kernel utility functions
+------------------------
+
+.. kernel-doc:: include/linux/kernel.h
+   :internal:
+
+.. kernel-doc:: kernel/printk/printk.c
+   :export:
+
+.. kernel-doc:: kernel/panic.c
+   :export:
+
+.. kernel-doc:: kernel/sys.c
+   :export:
+
+.. kernel-doc:: kernel/rcu/srcu.c
+   :export:
+
+.. kernel-doc:: kernel/rcu/tree.c
+   :export:
+
+.. kernel-doc:: kernel/rcu/tree_plugin.h
+   :export:
+
+.. kernel-doc:: kernel/rcu/update.c
+   :export:
+
+Device Resource Management
+--------------------------
+
+.. kernel-doc:: drivers/base/devres.c
+   :export:
+
diff --git a/Documentation/driver-api/drivers.rst b/Documentation/driver-api/drivers.rst
deleted file mode 100644
index 17f99d441b52..000000000000
--- a/Documentation/driver-api/drivers.rst
+++ /dev/null
@@ -1,654 +0,0 @@
-====================
-Linux Device Drivers
-====================
-
-Driver Basics
-=============
-
-Driver Entry and Exit points
-----------------------------
-
-.. kernel-doc:: include/linux/init.h
-   :internal:
-
-Atomic and pointer manipulation
--------------------------------
-
-.. kernel-doc:: arch/x86/include/asm/atomic.h
-   :internal:
-
-Delaying, scheduling, and timer routines
-----------------------------------------
-
-.. kernel-doc:: include/linux/sched.h
-   :internal:
-
-.. kernel-doc:: kernel/sched/core.c
-   :export:
-
-.. kernel-doc:: kernel/sched/cpupri.c
-   :internal:
-
-.. kernel-doc:: kernel/sched/fair.c
-   :internal:
-
-.. kernel-doc:: include/linux/completion.h
-   :internal:
-
-.. kernel-doc:: kernel/time/timer.c
-   :export:
-
-Wait queues and Wake events
----------------------------
-
-.. kernel-doc:: include/linux/wait.h
-   :internal:
-
-.. kernel-doc:: kernel/sched/wait.c
-   :export:
-
-High-resolution timers
-----------------------
-
-.. kernel-doc:: include/linux/ktime.h
-   :internal:
-
-.. kernel-doc:: include/linux/hrtimer.h
-   :internal:
-
-.. kernel-doc:: kernel/time/hrtimer.c
-   :export:
-
-Workqueues and Kevents
-----------------------
-
-.. kernel-doc:: include/linux/workqueue.h
-   :internal:
-
-.. kernel-doc:: kernel/workqueue.c
-   :export:
-
-Internal Functions
-------------------
-
-.. kernel-doc:: kernel/exit.c
-   :internal:
-
-.. kernel-doc:: kernel/signal.c
-   :internal:
-
-.. kernel-doc:: include/linux/kthread.h
-   :internal:
-
-.. kernel-doc:: kernel/kthread.c
-   :export:
-
-Kernel objects manipulation
----------------------------
-
-.. kernel-doc:: lib/kobject.c
-   :export:
-
-Kernel utility functions
-------------------------
-
-.. kernel-doc:: include/linux/kernel.h
-   :internal:
-
-.. kernel-doc:: kernel/printk/printk.c
-   :export:
-
-.. kernel-doc:: kernel/panic.c
-   :export:
-
-.. kernel-doc:: kernel/sys.c
-   :export:
-
-.. kernel-doc:: kernel/rcu/srcu.c
-   :export:
-
-.. kernel-doc:: kernel/rcu/tree.c
-   :export:
-
-.. kernel-doc:: kernel/rcu/tree_plugin.h
-   :export:
-
-.. kernel-doc:: kernel/rcu/update.c
-   :export:
-
-Device Resource Management
---------------------------
-
-.. kernel-doc:: drivers/base/devres.c
-   :export:
-
-Device drivers infrastructure
-=============================
-
-The Basic Device Driver-Model Structures
-----------------------------------------
-
-.. kernel-doc:: include/linux/device.h
-   :internal:
-
-Device Drivers Base
--------------------
-
-.. kernel-doc:: drivers/base/init.c
-   :internal:
-
-.. kernel-doc:: drivers/base/driver.c
-   :export:
-
-.. kernel-doc:: drivers/base/core.c
-   :export:
-
-.. kernel-doc:: drivers/base/syscore.c
-   :export:
-
-.. kernel-doc:: drivers/base/class.c
-   :export:
-
-.. kernel-doc:: drivers/base/node.c
-   :internal:
-
-.. kernel-doc:: drivers/base/firmware_class.c
-   :export:
-
-.. kernel-doc:: drivers/base/transport_class.c
-   :export:
-
-.. kernel-doc:: drivers/base/dd.c
-   :export:
-
-.. kernel-doc:: include/linux/platform_device.h
-   :internal:
-
-.. kernel-doc:: drivers/base/platform.c
-   :export:
-
-.. kernel-doc:: drivers/base/bus.c
-   :export:
-
-Buffer Sharing and Synchronization
-----------------------------------
-
-The dma-buf subsystem provides the framework for sharing buffers for
-hardware (DMA) access across multiple device drivers and subsystems, and
-for synchronizing asynchronous hardware access.
-
-This is used, for example, by drm "prime" multi-GPU support, but is of
-course not limited to GPU use cases.
-
-The three main components of this are: (1) dma-buf, representing a
-sg_table and exposed to userspace as a file descriptor to allow passing
-between devices, (2) fence, which provides a mechanism to signal when
-one device as finished access, and (3) reservation, which manages the
-shared or exclusive fence(s) associated with the buffer.
-
-dma-buf
-~~~~~~~
-
-.. kernel-doc:: drivers/dma-buf/dma-buf.c
-   :export:
-
-.. kernel-doc:: include/linux/dma-buf.h
-   :internal:
-
-reservation
-~~~~~~~~~~~
-
-.. kernel-doc:: drivers/dma-buf/reservation.c
-   :doc: Reservation Object Overview
-
-.. kernel-doc:: drivers/dma-buf/reservation.c
-   :export:
-
-.. kernel-doc:: include/linux/reservation.h
-   :internal:
-
-fence
-~~~~~
-
-.. kernel-doc:: drivers/dma-buf/fence.c
-   :export:
-
-.. kernel-doc:: include/linux/fence.h
-   :internal:
-
-.. kernel-doc:: drivers/dma-buf/seqno-fence.c
-   :export:
-
-.. kernel-doc:: include/linux/seqno-fence.h
-   :internal:
-
-.. kernel-doc:: drivers/dma-buf/fence-array.c
-   :export:
-
-.. kernel-doc:: include/linux/fence-array.h
-   :internal:
-
-.. kernel-doc:: drivers/dma-buf/reservation.c
-   :export:
-
-.. kernel-doc:: include/linux/reservation.h
-   :internal:
-
-.. kernel-doc:: drivers/dma-buf/sync_file.c
-   :export:
-
-.. kernel-doc:: include/linux/sync_file.h
-   :internal:
-
-Device Drivers DMA Management
------------------------------
-
-.. kernel-doc:: drivers/base/dma-coherent.c
-   :export:
-
-.. kernel-doc:: drivers/base/dma-mapping.c
-   :export:
-
-Device Drivers Power Management
--------------------------------
-
-.. kernel-doc:: drivers/base/power/main.c
-   :export:
-
-Device Drivers ACPI Support
----------------------------
-
-.. kernel-doc:: drivers/acpi/scan.c
-   :export:
-
-.. kernel-doc:: drivers/acpi/scan.c
-   :internal:
-
-Device drivers PnP support
---------------------------
-
-.. kernel-doc:: drivers/pnp/core.c
-   :internal:
-
-.. kernel-doc:: drivers/pnp/card.c
-   :export:
-
-.. kernel-doc:: drivers/pnp/driver.c
-   :internal:
-
-.. kernel-doc:: drivers/pnp/manager.c
-   :export:
-
-.. kernel-doc:: drivers/pnp/support.c
-   :export:
-
-Userspace IO devices
---------------------
-
-.. kernel-doc:: drivers/uio/uio.c
-   :export:
-
-.. kernel-doc:: include/linux/uio_driver.h
-   :internal:
-
-Parallel Port Devices
-=====================
-
-.. kernel-doc:: include/linux/parport.h
-   :internal:
-
-.. kernel-doc:: drivers/parport/ieee1284.c
-   :export:
-
-.. kernel-doc:: drivers/parport/share.c
-   :export:
-
-.. kernel-doc:: drivers/parport/daisy.c
-   :internal:
-
-Message-based devices
-=====================
-
-Fusion message devices
-----------------------
-
-.. kernel-doc:: drivers/message/fusion/mptbase.c
-   :export:
-
-.. kernel-doc:: drivers/message/fusion/mptbase.c
-   :internal:
-
-.. kernel-doc:: drivers/message/fusion/mptscsih.c
-   :export:
-
-.. kernel-doc:: drivers/message/fusion/mptscsih.c
-   :internal:
-
-.. kernel-doc:: drivers/message/fusion/mptctl.c
-   :internal:
-
-.. kernel-doc:: drivers/message/fusion/mptspi.c
-   :internal:
-
-.. kernel-doc:: drivers/message/fusion/mptfc.c
-   :internal:
-
-.. kernel-doc:: drivers/message/fusion/mptlan.c
-   :internal:
-
-Sound Devices
-=============
-
-.. kernel-doc:: include/sound/core.h
-   :internal:
-
-.. kernel-doc:: sound/sound_core.c
-   :export:
-
-.. kernel-doc:: include/sound/pcm.h
-   :internal:
-
-.. kernel-doc:: sound/core/pcm.c
-   :export:
-
-.. kernel-doc:: sound/core/device.c
-   :export:
-
-.. kernel-doc:: sound/core/info.c
-   :export:
-
-.. kernel-doc:: sound/core/rawmidi.c
-   :export:
-
-.. kernel-doc:: sound/core/sound.c
-   :export:
-
-.. kernel-doc:: sound/core/memory.c
-   :export:
-
-.. kernel-doc:: sound/core/pcm_memory.c
-   :export:
-
-.. kernel-doc:: sound/core/init.c
-   :export:
-
-.. kernel-doc:: sound/core/isadma.c
-   :export:
-
-.. kernel-doc:: sound/core/control.c
-   :export:
-
-.. kernel-doc:: sound/core/pcm_lib.c
-   :export:
-
-.. kernel-doc:: sound/core/hwdep.c
-   :export:
-
-.. kernel-doc:: sound/core/pcm_native.c
-   :export:
-
-.. kernel-doc:: sound/core/memalloc.c
-   :export:
-
-16x50 UART Driver
-=================
-
-.. kernel-doc:: drivers/tty/serial/serial_core.c
-   :export:
-
-.. kernel-doc:: drivers/tty/serial/8250/8250_core.c
-   :export:
-
-Frame Buffer Library
-====================
-
-The frame buffer drivers depend heavily on four data structures. These
-structures are declared in include/linux/fb.h. They are fb_info,
-fb_var_screeninfo, fb_fix_screeninfo and fb_monospecs. The last
-three can be made available to and from userland.
-
-fb_info defines the current state of a particular video card. Inside
-fb_info, there exists a fb_ops structure which is a collection of
-needed functions to make fbdev and fbcon work. fb_info is only visible
-to the kernel.
-
-fb_var_screeninfo is used to describe the features of a video card
-that are user defined. With fb_var_screeninfo, things such as depth
-and the resolution may be defined.
-
-The next structure is fb_fix_screeninfo. This defines the properties
-of a card that are created when a mode is set and can't be changed
-otherwise. A good example of this is the start of the frame buffer
-memory. This "locks" the address of the frame buffer memory, so that it
-cannot be changed or moved.
-
-The last structure is fb_monospecs. In the old API, there was little
-importance for fb_monospecs. This allowed for forbidden things such as
-setting a mode of 800x600 on a fix frequency monitor. With the new API,
-fb_monospecs prevents such things, and if used correctly, can prevent a
-monitor from being cooked. fb_monospecs will not be useful until
-kernels 2.5.x.
-
-Frame Buffer Memory
--------------------
-
-.. kernel-doc:: drivers/video/fbdev/core/fbmem.c
-   :export:
-
-Frame Buffer Colormap
----------------------
-
-.. kernel-doc:: drivers/video/fbdev/core/fbcmap.c
-   :export:
-
-Frame Buffer Video Mode Database
---------------------------------
-
-.. kernel-doc:: drivers/video/fbdev/core/modedb.c
-   :internal:
-
-.. kernel-doc:: drivers/video/fbdev/core/modedb.c
-   :export:
-
-Frame Buffer Macintosh Video Mode Database
-------------------------------------------
-
-.. kernel-doc:: drivers/video/fbdev/macmodes.c
-   :export:
-
-Frame Buffer Fonts
-------------------
-
-Refer to the file lib/fonts/fonts.c for more information.
-
-Input Subsystem
-===============
-
-Input core
-----------
-
-.. kernel-doc:: include/linux/input.h
-   :internal:
-
-.. kernel-doc:: drivers/input/input.c
-   :export:
-
-.. kernel-doc:: drivers/input/ff-core.c
-   :export:
-
-.. kernel-doc:: drivers/input/ff-memless.c
-   :export:
-
-Multitouch Library
-------------------
-
-.. kernel-doc:: include/linux/input/mt.h
-   :internal:
-
-.. kernel-doc:: drivers/input/input-mt.c
-   :export:
-
-Polled input devices
---------------------
-
-.. kernel-doc:: include/linux/input-polldev.h
-   :internal:
-
-.. kernel-doc:: drivers/input/input-polldev.c
-   :export:
-
-Matrix keyboards/keypads
-------------------------
-
-.. kernel-doc:: include/linux/input/matrix_keypad.h
-   :internal:
-
-Sparse keymap support
----------------------
-
-.. kernel-doc:: include/linux/input/sparse-keymap.h
-   :internal:
-
-.. kernel-doc:: drivers/input/sparse-keymap.c
-   :export:
-
-Serial Peripheral Interface (SPI)
-=================================
-
-SPI is the "Serial Peripheral Interface", widely used with embedded
-systems because it is a simple and efficient interface: basically a
-multiplexed shift register. Its three signal wires hold a clock (SCK,
-often in the range of 1-20 MHz), a "Master Out, Slave In" (MOSI) data
-line, and a "Master In, Slave Out" (MISO) data line. SPI is a full
-duplex protocol; for each bit shifted out the MOSI line (one per clock)
-another is shifted in on the MISO line. Those bits are assembled into
-words of various sizes on the way to and from system memory. An
-additional chipselect line is usually active-low (nCS); four signals are
-normally used for each peripheral, plus sometimes an interrupt.
-
-The SPI bus facilities listed here provide a generalized interface to
-declare SPI busses and devices, manage them according to the standard
-Linux driver model, and perform input/output operations. At this time,
-only "master" side interfaces are supported, where Linux talks to SPI
-peripherals and does not implement such a peripheral itself. (Interfaces
-to support implementing SPI slaves would necessarily look different.)
-
-The programming interface is structured around two kinds of driver, and
-two kinds of device. A "Controller Driver" abstracts the controller
-hardware, which may be as simple as a set of GPIO pins or as complex as
-a pair of FIFOs connected to dual DMA engines on the other side of the
-SPI shift register (maximizing throughput). Such drivers bridge between
-whatever bus they sit on (often the platform bus) and SPI, and expose
-the SPI side of their device as a :c:type:`struct spi_master
-<spi_master>`. SPI devices are children of that master,
-represented as a :c:type:`struct spi_device <spi_device>` and
-manufactured from :c:type:`struct spi_board_info
-<spi_board_info>` descriptors which are usually provided by
-board-specific initialization code. A :c:type:`struct spi_driver
-<spi_driver>` is called a "Protocol Driver", and is bound to a
-spi_device using normal driver model calls.
-
-The I/O model is a set of queued messages. Protocol drivers submit one
-or more :c:type:`struct spi_message <spi_message>` objects,
-which are processed and completed asynchronously. (There are synchronous
-wrappers, however.) Messages are built from one or more
-:c:type:`struct spi_transfer <spi_transfer>` objects, each of
-which wraps a full duplex SPI transfer. A variety of protocol tweaking
-options are needed, because different chips adopt very different
-policies for how they use the bits transferred with SPI.
-
-.. kernel-doc:: include/linux/spi/spi.h
-   :internal:
-
-.. kernel-doc:: drivers/spi/spi.c
-   :functions: spi_register_board_info
-
-.. kernel-doc:: drivers/spi/spi.c
-   :export:
-
-I\ :sup:`2`\ C and SMBus Subsystem
-==================================
-
-I\ :sup:`2`\ C (or without fancy typography, "I2C") is an acronym for
-the "Inter-IC" bus, a simple bus protocol which is widely used where low
-data rate communications suffice. Since it's also a licensed trademark,
-some vendors use another name (such as "Two-Wire Interface", TWI) for
-the same bus. I2C only needs two signals (SCL for clock, SDA for data),
-conserving board real estate and minimizing signal quality issues. Most
-I2C devices use seven bit addresses, and bus speeds of up to 400 kHz;
-there's a high speed extension (3.4 MHz) that's not yet found wide use.
-I2C is a multi-master bus; open drain signaling is used to arbitrate
-between masters, as well as to handshake and to synchronize clocks from
-slower clients.
-
-The Linux I2C programming interfaces support only the master side of bus
-interactions, not the slave side. The programming interface is
-structured around two kinds of driver, and two kinds of device. An I2C
-"Adapter Driver" abstracts the controller hardware; it binds to a
-physical device (perhaps a PCI device or platform_device) and exposes a
-:c:type:`struct i2c_adapter <i2c_adapter>` representing each
-I2C bus segment it manages. On each I2C bus segment will be I2C devices
-represented by a :c:type:`struct i2c_client <i2c_client>`.
-Those devices will be bound to a :c:type:`struct i2c_driver
-<i2c_driver>`, which should follow the standard Linux driver
-model. (At this writing, a legacy model is more widely used.) There are
-functions to perform various I2C protocol operations; at this writing
-all such functions are usable only from task context.
-
-The System Management Bus (SMBus) is a sibling protocol. Most SMBus
-systems are also I2C conformant. The electrical constraints are tighter
-for SMBus, and it standardizes particular protocol messages and idioms.
-Controllers that support I2C can also support most SMBus operations, but
-SMBus controllers don't support all the protocol options that an I2C
-controller will. There are functions to perform various SMBus protocol
-operations, either using I2C primitives or by issuing SMBus commands to
-i2c_adapter devices which don't support those I2C operations.
-
-.. kernel-doc:: include/linux/i2c.h
-   :internal:
-
-.. kernel-doc:: drivers/i2c/i2c-boardinfo.c
-   :functions: i2c_register_board_info
-
-.. kernel-doc:: drivers/i2c/i2c-core.c
-   :export:
-
-High Speed Synchronous Serial Interface (HSI)
-=============================================
-
-High Speed Synchronous Serial Interface (HSI) is a serial interface
-mainly used for connecting application engines (APE) with cellular modem
-engines (CMT) in cellular handsets. HSI provides multiplexing for up to
-16 logical channels, low-latency and full duplex communication.
-
-.. kernel-doc:: include/linux/hsi/hsi.h
-   :internal:
-
-.. kernel-doc:: drivers/hsi/hsi_core.c
-   :export:
-
-Pulse-Width Modulation (PWM)
-============================
-
-Pulse-width modulation is a modulation technique primarily used to
-control power supplied to electrical devices.
-
-The PWM framework provides an abstraction for providers and consumers of
-PWM signals. A controller that provides one or more PWM signals is
-registered as :c:type:`struct pwm_chip <pwm_chip>`. Providers
-are expected to embed this structure in a driver-specific structure.
-This structure contains fields that describe a particular chip.
-
-A chip exposes one or more PWM signal sources, each of which exposed as
-a :c:type:`struct pwm_device <pwm_device>`. Operations can be
-performed on PWM devices to control the period, duty cycle, polarity and
-active state of the signal.
-
-Note that PWM devices are exclusive resources: they can always only be
-used by one consumer at a time.
-
-.. kernel-doc:: include/linux/pwm.h
-   :internal:
-
-.. kernel-doc:: drivers/pwm/core.c
-   :export:
diff --git a/Documentation/driver-api/frame-buffer.rst b/Documentation/driver-api/frame-buffer.rst
new file mode 100644
index 000000000000..9dd3060f027d
--- /dev/null
+++ b/Documentation/driver-api/frame-buffer.rst
@@ -0,0 +1,62 @@
+Frame Buffer Library
+====================
+
+The frame buffer drivers depend heavily on four data structures. These
+structures are declared in include/linux/fb.h. They are fb_info,
+fb_var_screeninfo, fb_fix_screeninfo and fb_monospecs. The last
+three can be made available to and from userland.
+
+fb_info defines the current state of a particular video card. Inside
+fb_info, there exists a fb_ops structure which is a collection of
+needed functions to make fbdev and fbcon work. fb_info is only visible
+to the kernel.
+
+fb_var_screeninfo is used to describe the features of a video card
+that are user defined. With fb_var_screeninfo, things such as depth
+and the resolution may be defined.
+
+The next structure is fb_fix_screeninfo. This defines the properties
+of a card that are created when a mode is set and can't be changed
+otherwise. A good example of this is the start of the frame buffer
+memory. This "locks" the address of the frame buffer memory, so that it
+cannot be changed or moved.
+
+The last structure is fb_monospecs. In the old API, there was little
+importance for fb_monospecs. This allowed for forbidden things such as
+setting a mode of 800x600 on a fix frequency monitor. With the new API,
+fb_monospecs prevents such things, and if used correctly, can prevent a
+monitor from being cooked. fb_monospecs will not be useful until
+kernels 2.5.x.
+
+Frame Buffer Memory
+-------------------
+
+.. kernel-doc:: drivers/video/fbdev/core/fbmem.c
+   :export:
+
+Frame Buffer Colormap
+---------------------
+
+.. kernel-doc:: drivers/video/fbdev/core/fbcmap.c
+   :export:
+
+Frame Buffer Video Mode Database
+--------------------------------
+
+.. kernel-doc:: drivers/video/fbdev/core/modedb.c
+   :internal:
+
+.. kernel-doc:: drivers/video/fbdev/core/modedb.c
+   :export:
+
+Frame Buffer Macintosh Video Mode Database
+------------------------------------------
+
+.. kernel-doc:: drivers/video/fbdev/macmodes.c
+   :export:
+
+Frame Buffer Fonts
+------------------
+
+Refer to the file lib/fonts/fonts.c for more information.
+
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
new file mode 100644
index 000000000000..b50c41011e47
--- /dev/null
+++ b/Documentation/driver-api/index.rst
@@ -0,0 +1,24 @@
+========================================
+The Linux driver implementer's API guide
+========================================
+
+The kernel offers a wide variety of interfaces to support the development
+of device drivers.  This document is an only somewhat organized collection
+of some of those interfaces — it will hopefully get better over time!  The
+available subsections can be seen below.
+
+.. class:: toc-title
+
+           Table of contents
+
+.. toctree::
+   :maxdepth: 2
+
+   basics
+   infrastructure
+   message-based
+   sound
+   frame-buffer
+   input
+   serial-interfaces
+   miscellaneous
diff --git a/Documentation/driver-api/infrastructure.rst b/Documentation/driver-api/infrastructure.rst
new file mode 100644
index 000000000000..5d50d6733db3
--- /dev/null
+++ b/Documentation/driver-api/infrastructure.rst
@@ -0,0 +1,169 @@
+Device drivers infrastructure
+=============================
+
+The Basic Device Driver-Model Structures
+----------------------------------------
+
+.. kernel-doc:: include/linux/device.h
+   :internal:
+
+Device Drivers Base
+-------------------
+
+.. kernel-doc:: drivers/base/init.c
+   :internal:
+
+.. kernel-doc:: drivers/base/driver.c
+   :export:
+
+.. kernel-doc:: drivers/base/core.c
+   :export:
+
+.. kernel-doc:: drivers/base/syscore.c
+   :export:
+
+.. kernel-doc:: drivers/base/class.c
+   :export:
+
+.. kernel-doc:: drivers/base/node.c
+   :internal:
+
+.. kernel-doc:: drivers/base/firmware_class.c
+   :export:
+
+.. kernel-doc:: drivers/base/transport_class.c
+   :export:
+
+.. kernel-doc:: drivers/base/dd.c
+   :export:
+
+.. kernel-doc:: include/linux/platform_device.h
+   :internal:
+
+.. kernel-doc:: drivers/base/platform.c
+   :export:
+
+.. kernel-doc:: drivers/base/bus.c
+   :export:
+
+Buffer Sharing and Synchronization
+----------------------------------
+
+The dma-buf subsystem provides the framework for sharing buffers for
+hardware (DMA) access across multiple device drivers and subsystems, and
+for synchronizing asynchronous hardware access.
+
+This is used, for example, by drm "prime" multi-GPU support, but is of
+course not limited to GPU use cases.
+
+The three main components of this are: (1) dma-buf, representing a
+sg_table and exposed to userspace as a file descriptor to allow passing
+between devices, (2) fence, which provides a mechanism to signal when
+one device as finished access, and (3) reservation, which manages the
+shared or exclusive fence(s) associated with the buffer.
+
+dma-buf
+~~~~~~~
+
+.. kernel-doc:: drivers/dma-buf/dma-buf.c
+   :export:
+
+.. kernel-doc:: include/linux/dma-buf.h
+   :internal:
+
+reservation
+~~~~~~~~~~~
+
+.. kernel-doc:: drivers/dma-buf/reservation.c
+   :doc: Reservation Object Overview
+
+.. kernel-doc:: drivers/dma-buf/reservation.c
+   :export:
+
+.. kernel-doc:: include/linux/reservation.h
+   :internal:
+
+fence
+~~~~~
+
+.. kernel-doc:: drivers/dma-buf/fence.c
+   :export:
+
+.. kernel-doc:: include/linux/fence.h
+   :internal:
+
+.. kernel-doc:: drivers/dma-buf/seqno-fence.c
+   :export:
+
+.. kernel-doc:: include/linux/seqno-fence.h
+   :internal:
+
+.. kernel-doc:: drivers/dma-buf/fence-array.c
+   :export:
+
+.. kernel-doc:: include/linux/fence-array.h
+   :internal:
+
+.. kernel-doc:: drivers/dma-buf/reservation.c
+   :export:
+
+.. kernel-doc:: include/linux/reservation.h
+   :internal:
+
+.. kernel-doc:: drivers/dma-buf/sync_file.c
+   :export:
+
+.. kernel-doc:: include/linux/sync_file.h
+   :internal:
+
+Device Drivers DMA Management
+-----------------------------
+
+.. kernel-doc:: drivers/base/dma-coherent.c
+   :export:
+
+.. kernel-doc:: drivers/base/dma-mapping.c
+   :export:
+
+Device Drivers Power Management
+-------------------------------
+
+.. kernel-doc:: drivers/base/power/main.c
+   :export:
+
+Device Drivers ACPI Support
+---------------------------
+
+.. kernel-doc:: drivers/acpi/scan.c
+   :export:
+
+.. kernel-doc:: drivers/acpi/scan.c
+   :internal:
+
+Device drivers PnP support
+--------------------------
+
+.. kernel-doc:: drivers/pnp/core.c
+   :internal:
+
+.. kernel-doc:: drivers/pnp/card.c
+   :export:
+
+.. kernel-doc:: drivers/pnp/driver.c
+   :internal:
+
+.. kernel-doc:: drivers/pnp/manager.c
+   :export:
+
+.. kernel-doc:: drivers/pnp/support.c
+   :export:
+
+Userspace IO devices
+--------------------
+
+.. kernel-doc:: drivers/uio/uio.c
+   :export:
+
+.. kernel-doc:: include/linux/uio_driver.h
+   :internal:
+
diff --git a/Documentation/driver-api/input.rst b/Documentation/driver-api/input.rst
new file mode 100644
index 000000000000..d05bf58fa83e
--- /dev/null
+++ b/Documentation/driver-api/input.rst
@@ -0,0 +1,51 @@
+Input Subsystem
+===============
+
+Input core
+----------
+
+.. kernel-doc:: include/linux/input.h
+   :internal:
+
+.. kernel-doc:: drivers/input/input.c
+   :export:
+
+.. kernel-doc:: drivers/input/ff-core.c
+   :export:
+
+.. kernel-doc:: drivers/input/ff-memless.c
+   :export:
+
+Multitouch Library
+------------------
+
+.. kernel-doc:: include/linux/input/mt.h
+   :internal:
+
+.. kernel-doc:: drivers/input/input-mt.c
+   :export:
+
+Polled input devices
+--------------------
+
+.. kernel-doc:: include/linux/input-polldev.h
+   :internal:
+
+.. kernel-doc:: drivers/input/input-polldev.c
+   :export:
+
+Matrix keyboards/keypads
+------------------------
+
+.. kernel-doc:: include/linux/input/matrix_keypad.h
+   :internal:
+
+Sparse keymap support
+---------------------
+
+.. kernel-doc:: include/linux/input/sparse-keymap.h
+   :internal:
+
+.. kernel-doc:: drivers/input/sparse-keymap.c
+   :export:
+
diff --git a/Documentation/driver-api/message-based.rst b/Documentation/driver-api/message-based.rst
new file mode 100644
index 000000000000..ef5867a7de20
--- /dev/null
+++ b/Documentation/driver-api/message-based.rst
@@ -0,0 +1,30 @@
+Message-based devices
+=====================
+
+Fusion message devices
+----------------------
+
+.. kernel-doc:: drivers/message/fusion/mptbase.c
+   :export:
+
+.. kernel-doc:: drivers/message/fusion/mptbase.c
+   :internal:
+
+.. kernel-doc:: drivers/message/fusion/mptscsih.c
+   :export:
+
+.. kernel-doc:: drivers/message/fusion/mptscsih.c
+   :internal:
+
+.. kernel-doc:: drivers/message/fusion/mptctl.c
+   :internal:
+
+.. kernel-doc:: drivers/message/fusion/mptspi.c
+   :internal:
+
+.. kernel-doc:: drivers/message/fusion/mptfc.c
+   :internal:
+
+.. kernel-doc:: drivers/message/fusion/mptlan.c
+   :internal:
+
diff --git a/Documentation/driver-api/miscellaneous.rst b/Documentation/driver-api/miscellaneous.rst
new file mode 100644
index 000000000000..8da7d115bafc
--- /dev/null
+++ b/Documentation/driver-api/miscellaneous.rst
@@ -0,0 +1,50 @@
+Parallel Port Devices
+=====================
+
+.. kernel-doc:: include/linux/parport.h
+   :internal:
+
+.. kernel-doc:: drivers/parport/ieee1284.c
+   :export:
+
+.. kernel-doc:: drivers/parport/share.c
+   :export:
+
+.. kernel-doc:: drivers/parport/daisy.c
+   :internal:
+
+16x50 UART Driver
+=================
+
+.. kernel-doc:: drivers/tty/serial/serial_core.c
+   :export:
+
+.. kernel-doc:: drivers/tty/serial/8250/8250_core.c
+   :export:
+
+Pulse-Width Modulation (PWM)
+============================
+
+Pulse-width modulation is a modulation technique primarily used to
+control power supplied to electrical devices.
+
+The PWM framework provides an abstraction for providers and consumers of
+PWM signals. A controller that provides one or more PWM signals is
+registered as :c:type:`struct pwm_chip <pwm_chip>`. Providers
+are expected to embed this structure in a driver-specific structure.
+This structure contains fields that describe a particular chip.
+
+A chip exposes one or more PWM signal sources, each of which exposed as
+a :c:type:`struct pwm_device <pwm_device>`. Operations can be
+performed on PWM devices to control the period, duty cycle, polarity and
+active state of the signal.
+
+Note that PWM devices are exclusive resources: they can always only be
+used by one consumer at a time.
+
+.. kernel-doc:: include/linux/pwm.h
+   :internal:
+
+.. kernel-doc:: drivers/pwm/core.c
+   :export:
+   
diff --git a/Documentation/driver-api/serial-interfaces.rst b/Documentation/driver-api/serial-interfaces.rst
new file mode 100644
index 000000000000..d0d65e58c14b
--- /dev/null
+++ b/Documentation/driver-api/serial-interfaces.rst
@@ -0,0 +1,115 @@
+Serial Peripheral Interface (SPI)
+=================================
+
+SPI is the "Serial Peripheral Interface", widely used with embedded
+systems because it is a simple and efficient interface: basically a
+multiplexed shift register. Its three signal wires hold a clock (SCK,
+often in the range of 1-20 MHz), a "Master Out, Slave In" (MOSI) data
+line, and a "Master In, Slave Out" (MISO) data line. SPI is a full
+duplex protocol; for each bit shifted out the MOSI line (one per clock)
+another is shifted in on the MISO line. Those bits are assembled into
+words of various sizes on the way to and from system memory. An
+additional chipselect line is usually active-low (nCS); four signals are
+normally used for each peripheral, plus sometimes an interrupt.
+
+The SPI bus facilities listed here provide a generalized interface to
+declare SPI busses and devices, manage them according to the standard
+Linux driver model, and perform input/output operations. At this time,
+only "master" side interfaces are supported, where Linux talks to SPI
+peripherals and does not implement such a peripheral itself. (Interfaces
+to support implementing SPI slaves would necessarily look different.)
+
+The programming interface is structured around two kinds of driver, and
+two kinds of device. A "Controller Driver" abstracts the controller
+hardware, which may be as simple as a set of GPIO pins or as complex as
+a pair of FIFOs connected to dual DMA engines on the other side of the
+SPI shift register (maximizing throughput). Such drivers bridge between
+whatever bus they sit on (often the platform bus) and SPI, and expose
+the SPI side of their device as a :c:type:`struct spi_master
+<spi_master>`. SPI devices are children of that master,
+represented as a :c:type:`struct spi_device <spi_device>` and
+manufactured from :c:type:`struct spi_board_info
+<spi_board_info>` descriptors which are usually provided by
+board-specific initialization code. A :c:type:`struct spi_driver
+<spi_driver>` is called a "Protocol Driver", and is bound to a
+spi_device using normal driver model calls.
+
+The I/O model is a set of queued messages. Protocol drivers submit one
+or more :c:type:`struct spi_message <spi_message>` objects,
+which are processed and completed asynchronously. (There are synchronous
+wrappers, however.) Messages are built from one or more
+:c:type:`struct spi_transfer <spi_transfer>` objects, each of
+which wraps a full duplex SPI transfer. A variety of protocol tweaking
+options are needed, because different chips adopt very different
+policies for how they use the bits transferred with SPI.
+
+.. kernel-doc:: include/linux/spi/spi.h
+   :internal:
+
+.. kernel-doc:: drivers/spi/spi.c
+   :functions: spi_register_board_info
+
+.. kernel-doc:: drivers/spi/spi.c
+   :export:
+
+I\ :sup:`2`\ C and SMBus Subsystem
+==================================
+
+I\ :sup:`2`\ C (or without fancy typography, "I2C") is an acronym for
+the "Inter-IC" bus, a simple bus protocol which is widely used where low
+data rate communications suffice. Since it's also a licensed trademark,
+some vendors use another name (such as "Two-Wire Interface", TWI) for
+the same bus. I2C only needs two signals (SCL for clock, SDA for data),
+conserving board real estate and minimizing signal quality issues. Most
+I2C devices use seven bit addresses, and bus speeds of up to 400 kHz;
+there's a high speed extension (3.4 MHz) that's not yet found wide use.
+I2C is a multi-master bus; open drain signaling is used to arbitrate
+between masters, as well as to handshake and to synchronize clocks from
+slower clients.
+
+The Linux I2C programming interfaces support only the master side of bus
+interactions, not the slave side. The programming interface is
+structured around two kinds of driver, and two kinds of device. An I2C
+"Adapter Driver" abstracts the controller hardware; it binds to a
+physical device (perhaps a PCI device or platform_device) and exposes a
+:c:type:`struct i2c_adapter <i2c_adapter>` representing each
+I2C bus segment it manages. On each I2C bus segment will be I2C devices
+represented by a :c:type:`struct i2c_client <i2c_client>`.
+Those devices will be bound to a :c:type:`struct i2c_driver
+<i2c_driver>`, which should follow the standard Linux driver
+model. (At this writing, a legacy model is more widely used.) There are
+functions to perform various I2C protocol operations; at this writing
+all such functions are usable only from task context.
+
+The System Management Bus (SMBus) is a sibling protocol. Most SMBus
+systems are also I2C conformant. The electrical constraints are tighter
+for SMBus, and it standardizes particular protocol messages and idioms.
+Controllers that support I2C can also support most SMBus operations, but
+SMBus controllers don't support all the protocol options that an I2C
+controller will. There are functions to perform various SMBus protocol
+operations, either using I2C primitives or by issuing SMBus commands to
+i2c_adapter devices which don't support those I2C operations.
+
+.. kernel-doc:: include/linux/i2c.h
+   :internal:
+
+.. kernel-doc:: drivers/i2c/i2c-boardinfo.c
+   :functions: i2c_register_board_info
+
+.. kernel-doc:: drivers/i2c/i2c-core.c
+   :export:
+
+High Speed Synchronous Serial Interface (HSI)
+=============================================
+
+High Speed Synchronous Serial Interface (HSI) is a serial interface
+mainly used for connecting application engines (APE) with cellular modem
+engines (CMT) in cellular handsets. HSI provides multiplexing for up to
+16 logical channels, low-latency and full duplex communication.
+
+.. kernel-doc:: include/linux/hsi/hsi.h
+   :internal:
+
+.. kernel-doc:: drivers/hsi/hsi_core.c
+   :export:
+
diff --git a/Documentation/driver-api/sound.rst b/Documentation/driver-api/sound.rst
new file mode 100644
index 000000000000..afef6eabc073
--- /dev/null
+++ b/Documentation/driver-api/sound.rst
@@ -0,0 +1,54 @@
+Sound Devices
+=============
+
+.. kernel-doc:: include/sound/core.h
+   :internal:
+
+.. kernel-doc:: sound/sound_core.c
+   :export:
+
+.. kernel-doc:: include/sound/pcm.h
+   :internal:
+
+.. kernel-doc:: sound/core/pcm.c
+   :export:
+
+.. kernel-doc:: sound/core/device.c
+   :export:
+
+.. kernel-doc:: sound/core/info.c
+   :export:
+
+.. kernel-doc:: sound/core/rawmidi.c
+   :export:
+
+.. kernel-doc:: sound/core/sound.c
+   :export:
+
+.. kernel-doc:: sound/core/memory.c
+   :export:
+
+.. kernel-doc:: sound/core/pcm_memory.c
+   :export:
+
+.. kernel-doc:: sound/core/init.c
+   :export:
+
+.. kernel-doc:: sound/core/isadma.c
+   :export:
+
+.. kernel-doc:: sound/core/control.c
+   :export:
+
+.. kernel-doc:: sound/core/pcm_lib.c
+   :export:
+
+.. kernel-doc:: sound/core/hwdep.c
+   :export:
+
+.. kernel-doc:: sound/core/pcm_native.c
+   :export:
+
+.. kernel-doc:: sound/core/memalloc.c
+   :export:
+
diff --git a/Documentation/index.rst b/Documentation/index.rst
index 0d6992b897c8..9fe5e0cacdd0 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -13,7 +13,7 @@ Contents:
 
    kernel-documentation
    dev-tools/tools
-   driver-api/drivers
+   driver-api/index
    media/index
    gpu/index