About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / DocBook / device-drivers.tmpl




Custom Search

Based on kernel version 4.0. Page generated on 2015-04-14 21:23 EST.

1	<?xml version="1.0" encoding="UTF-8"?>
2	<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
3		"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
4	
5	<book id="LinuxDriversAPI">
6	 <bookinfo>
7	  <title>Linux Device Drivers</title>
8	
9	  <legalnotice>
10	   <para>
11	     This documentation is free software; you can redistribute
12	     it and/or modify it under the terms of the GNU General Public
13	     License as published by the Free Software Foundation; either
14	     version 2 of the License, or (at your option) any later
15	     version.
16	   </para>
17	
18	   <para>
19	     This program is distributed in the hope that it will be
20	     useful, but WITHOUT ANY WARRANTY; without even the implied
21	     warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22	     See the GNU General Public License for more details.
23	   </para>
24	
25	   <para>
26	     You should have received a copy of the GNU General Public
27	     License along with this program; if not, write to the Free
28	     Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29	     MA 02111-1307 USA
30	   </para>
31	
32	   <para>
33	     For more details see the file COPYING in the source
34	     distribution of Linux.
35	   </para>
36	  </legalnotice>
37	 </bookinfo>
38	
39	<toc></toc>
40	
41	  <chapter id="Basics">
42	     <title>Driver Basics</title>
43	     <sect1><title>Driver Entry and Exit points</title>
44	!Iinclude/linux/init.h
45	     </sect1>
46	
47	     <sect1><title>Atomic and pointer manipulation</title>
48	!Iarch/x86/include/asm/atomic.h
49	     </sect1>
50	
51	     <sect1><title>Delaying, scheduling, and timer routines</title>
52	!Iinclude/linux/sched.h
53	!Ekernel/sched/core.c
54	!Ikernel/sched/cpupri.c
55	!Ikernel/sched/fair.c
56	!Iinclude/linux/completion.h
57	!Ekernel/time/timer.c
58	     </sect1>
59	     <sect1><title>Wait queues and Wake events</title>
60	!Iinclude/linux/wait.h
61	!Ekernel/sched/wait.c
62	     </sect1>
63	     <sect1><title>High-resolution timers</title>
64	!Iinclude/linux/ktime.h
65	!Iinclude/linux/hrtimer.h
66	!Ekernel/time/hrtimer.c
67	     </sect1>
68	     <sect1><title>Workqueues and Kevents</title>
69	!Ekernel/workqueue.c
70	     </sect1>
71	     <sect1><title>Internal Functions</title>
72	!Ikernel/exit.c
73	!Ikernel/signal.c
74	!Iinclude/linux/kthread.h
75	!Ekernel/kthread.c
76	     </sect1>
77	
78	     <sect1><title>Kernel objects manipulation</title>
79	<!--
80	X!Iinclude/linux/kobject.h
81	-->
82	!Elib/kobject.c
83	     </sect1>
84	
85	     <sect1><title>Kernel utility functions</title>
86	!Iinclude/linux/kernel.h
87	!Ekernel/printk/printk.c
88	!Ekernel/panic.c
89	!Ekernel/sys.c
90	!Ekernel/rcu/srcu.c
91	!Ekernel/rcu/tree.c
92	!Ekernel/rcu/tree_plugin.h
93	!Ekernel/rcu/update.c
94	     </sect1>
95	
96	     <sect1><title>Device Resource Management</title>
97	!Edrivers/base/devres.c
98	     </sect1>
99	
100	  </chapter>
101	
102	  <chapter id="devdrivers">
103	     <title>Device drivers infrastructure</title>
104	     <sect1><title>The Basic Device Driver-Model Structures </title>
105	!Iinclude/linux/device.h
106	     </sect1>
107	     <sect1><title>Device Drivers Base</title>
108	!Idrivers/base/init.c
109	!Edrivers/base/driver.c
110	!Edrivers/base/core.c
111	!Edrivers/base/syscore.c
112	!Edrivers/base/class.c
113	!Idrivers/base/node.c
114	!Edrivers/base/firmware_class.c
115	!Edrivers/base/transport_class.c
116	<!-- Cannot be included, because
117	     attribute_container_add_class_device_adapter
118	 and attribute_container_classdev_to_container
119	     exceed allowed 44 characters maximum
120	X!Edrivers/base/attribute_container.c
121	-->
122	!Edrivers/base/dd.c
123	<!--
124	X!Edrivers/base/interface.c
125	-->
126	!Iinclude/linux/platform_device.h
127	!Edrivers/base/platform.c
128	!Edrivers/base/bus.c
129	     </sect1>
130	     <sect1><title>Device Drivers DMA Management</title>
131	!Edrivers/dma-buf/dma-buf.c
132	!Edrivers/dma-buf/fence.c
133	!Edrivers/dma-buf/seqno-fence.c
134	!Iinclude/linux/fence.h
135	!Iinclude/linux/seqno-fence.h
136	!Edrivers/dma-buf/reservation.c
137	!Iinclude/linux/reservation.h
138	!Edrivers/base/dma-coherent.c
139	!Edrivers/base/dma-mapping.c
140	     </sect1>
141	     <sect1><title>Device Drivers Power Management</title>
142	!Edrivers/base/power/main.c
143	     </sect1>
144	     <sect1><title>Device Drivers ACPI Support</title>
145	<!-- Internal functions only
146	X!Edrivers/acpi/sleep/main.c
147	X!Edrivers/acpi/sleep/wakeup.c
148	X!Edrivers/acpi/motherboard.c
149	X!Edrivers/acpi/bus.c
150	-->
151	!Edrivers/acpi/scan.c
152	!Idrivers/acpi/scan.c
153	<!-- No correct structured comments
154	X!Edrivers/acpi/pci_bind.c
155	-->
156	     </sect1>
157	     <sect1><title>Device drivers PnP support</title>
158	!Idrivers/pnp/core.c
159	<!-- No correct structured comments
160	X!Edrivers/pnp/system.c
161	 -->
162	!Edrivers/pnp/card.c
163	!Idrivers/pnp/driver.c
164	!Edrivers/pnp/manager.c
165	!Edrivers/pnp/support.c
166	     </sect1>
167	     <sect1><title>Userspace IO devices</title>
168	!Edrivers/uio/uio.c
169	!Iinclude/linux/uio_driver.h
170	     </sect1>
171	  </chapter>
172	
173	  <chapter id="parportdev">
174	     <title>Parallel Port Devices</title>
175	!Iinclude/linux/parport.h
176	!Edrivers/parport/ieee1284.c
177	!Edrivers/parport/share.c
178	!Idrivers/parport/daisy.c
179	  </chapter>
180	
181	  <chapter id="message_devices">
182		<title>Message-based devices</title>
183	     <sect1><title>Fusion message devices</title>
184	!Edrivers/message/fusion/mptbase.c
185	!Idrivers/message/fusion/mptbase.c
186	!Edrivers/message/fusion/mptscsih.c
187	!Idrivers/message/fusion/mptscsih.c
188	!Idrivers/message/fusion/mptctl.c
189	!Idrivers/message/fusion/mptspi.c
190	!Idrivers/message/fusion/mptfc.c
191	!Idrivers/message/fusion/mptlan.c
192	     </sect1>
193	  </chapter>
194	
195	  <chapter id="snddev">
196	     <title>Sound Devices</title>
197	!Iinclude/sound/core.h
198	!Esound/sound_core.c
199	!Iinclude/sound/pcm.h
200	!Esound/core/pcm.c
201	!Esound/core/device.c
202	!Esound/core/info.c
203	!Esound/core/rawmidi.c
204	!Esound/core/sound.c
205	!Esound/core/memory.c
206	!Esound/core/pcm_memory.c
207	!Esound/core/init.c
208	!Esound/core/isadma.c
209	!Esound/core/control.c
210	!Esound/core/pcm_lib.c
211	!Esound/core/hwdep.c
212	!Esound/core/pcm_native.c
213	!Esound/core/memalloc.c
214	<!-- FIXME: Removed for now since no structured comments in source
215	X!Isound/sound_firmware.c
216	-->
217	  </chapter>
218	
219	  <chapter id="uart16x50">
220	     <title>16x50 UART Driver</title>
221	!Edrivers/tty/serial/serial_core.c
222	!Edrivers/tty/serial/8250/8250_core.c
223	  </chapter>
224	
225	  <chapter id="fbdev">
226	     <title>Frame Buffer Library</title>
227	
228	     <para>
229	       The frame buffer drivers depend heavily on four data structures.
230	       These structures are declared in include/linux/fb.h.  They are
231	       fb_info, fb_var_screeninfo, fb_fix_screeninfo and fb_monospecs.
232	       The last three can be made available to and from userland.
233	     </para>
234	
235	     <para>
236	       fb_info defines the current state of a particular video card.
237	       Inside fb_info, there exists a fb_ops structure which is a
238	       collection of needed functions to make fbdev and fbcon work.
239	       fb_info is only visible to the kernel.
240	     </para>
241	
242	     <para>
243	       fb_var_screeninfo is used to describe the features of a video card
244	       that are user defined.  With fb_var_screeninfo, things such as
245	       depth and the resolution may be defined.
246	     </para>
247	
248	     <para>
249	       The next structure is fb_fix_screeninfo. This defines the
250	       properties of a card that are created when a mode is set and can't
251	       be changed otherwise.  A good example of this is the start of the
252	       frame buffer memory.  This "locks" the address of the frame buffer
253	       memory, so that it cannot be changed or moved.
254	     </para>
255	
256	     <para>
257	       The last structure is fb_monospecs. In the old API, there was
258	       little importance for fb_monospecs. This allowed for forbidden things
259	       such as setting a mode of 800x600 on a fix frequency monitor. With
260	       the new API, fb_monospecs prevents such things, and if used
261	       correctly, can prevent a monitor from being cooked.  fb_monospecs
262	       will not be useful until kernels 2.5.x.
263	     </para>
264	
265	     <sect1><title>Frame Buffer Memory</title>
266	!Edrivers/video/fbdev/core/fbmem.c
267	     </sect1>
268	<!--
269	     <sect1><title>Frame Buffer Console</title>
270	X!Edrivers/video/console/fbcon.c
271	     </sect1>
272	-->
273	     <sect1><title>Frame Buffer Colormap</title>
274	!Edrivers/video/fbdev/core/fbcmap.c
275	     </sect1>
276	<!-- FIXME:
277	  drivers/video/fbgen.c has no docs, which stuffs up the sgml.  Comment
278	  out until somebody adds docs.  KAO
279	     <sect1><title>Frame Buffer Generic Functions</title>
280	X!Idrivers/video/fbgen.c
281	     </sect1>
282	KAO -->
283	     <sect1><title>Frame Buffer Video Mode Database</title>
284	!Idrivers/video/fbdev/core/modedb.c
285	!Edrivers/video/fbdev/core/modedb.c
286	     </sect1>
287	     <sect1><title>Frame Buffer Macintosh Video Mode Database</title>
288	!Edrivers/video/fbdev/macmodes.c
289	     </sect1>
290	     <sect1><title>Frame Buffer Fonts</title>
291	        <para>
292	           Refer to the file lib/fonts/fonts.c for more information.
293	        </para>
294	<!-- FIXME: Removed for now since no structured comments in source
295	X!Ilib/fonts/fonts.c
296	-->
297	     </sect1>
298	  </chapter>
299	
300	  <chapter id="input_subsystem">
301	     <title>Input Subsystem</title>
302	     <sect1><title>Input core</title>
303	!Iinclude/linux/input.h
304	!Edrivers/input/input.c
305	!Edrivers/input/ff-core.c
306	!Edrivers/input/ff-memless.c
307	     </sect1>
308	     <sect1><title>Multitouch Library</title>
309	!Iinclude/linux/input/mt.h
310	!Edrivers/input/input-mt.c
311	     </sect1>
312	     <sect1><title>Polled input devices</title>
313	!Iinclude/linux/input-polldev.h
314	!Edrivers/input/input-polldev.c
315	     </sect1>
316	     <sect1><title>Matrix keyboars/keypads</title>
317	!Iinclude/linux/input/matrix_keypad.h
318	     </sect1>
319	     <sect1><title>Sparse keymap support</title>
320	!Iinclude/linux/input/sparse-keymap.h
321	!Edrivers/input/sparse-keymap.c
322	     </sect1>
323	  </chapter>
324	
325	  <chapter id="spi">
326	      <title>Serial Peripheral Interface (SPI)</title>
327	  <para>
328		SPI is the "Serial Peripheral Interface", widely used with
329		embedded systems because it is a simple and efficient
330		interface:  basically a multiplexed shift register.
331		Its three signal wires hold a clock (SCK, often in the range
332		of 1-20 MHz), a "Master Out, Slave In" (MOSI) data line, and
333		a "Master In, Slave Out" (MISO) data line.
334		SPI is a full duplex protocol; for each bit shifted out the
335		MOSI line (one per clock) another is shifted in on the MISO line.
336		Those bits are assembled into words of various sizes on the
337		way to and from system memory.
338		An additional chipselect line is usually active-low (nCS);
339		four signals are normally used for each peripheral, plus
340		sometimes an interrupt.
341	  </para>
342	  <para>
343		The SPI bus facilities listed here provide a generalized
344		interface to declare SPI busses and devices, manage them
345		according to the standard Linux driver model, and perform
346		input/output operations.
347		At this time, only "master" side interfaces are supported,
348		where Linux talks to SPI peripherals and does not implement
349		such a peripheral itself.
350		(Interfaces to support implementing SPI slaves would
351		necessarily look different.)
352	  </para>
353	  <para>
354		The programming interface is structured around two kinds of driver,
355		and two kinds of device.
356		A "Controller Driver" abstracts the controller hardware, which may
357		be as simple as a set of GPIO pins or as complex as a pair of FIFOs
358		connected to dual DMA engines on the other side of the SPI shift
359		register (maximizing throughput).  Such drivers bridge between
360		whatever bus they sit on (often the platform bus) and SPI, and
361		expose the SPI side of their device as a
362		<structname>struct spi_master</structname>.
363		SPI devices are children of that master, represented as a
364		<structname>struct spi_device</structname> and manufactured from
365		<structname>struct spi_board_info</structname> descriptors which
366		are usually provided by board-specific initialization code.
367		A <structname>struct spi_driver</structname> is called a
368		"Protocol Driver", and is bound to a spi_device using normal
369		driver model calls.
370	  </para>
371	  <para>
372		The I/O model is a set of queued messages.  Protocol drivers
373		submit one or more <structname>struct spi_message</structname>
374		objects, which are processed and completed asynchronously.
375		(There are synchronous wrappers, however.)  Messages are
376		built from one or more <structname>struct spi_transfer</structname>
377		objects, each of which wraps a full duplex SPI transfer.
378		A variety of protocol tweaking options are needed, because
379		different chips adopt very different policies for how they
380		use the bits transferred with SPI.
381	  </para>
382	!Iinclude/linux/spi/spi.h
383	!Fdrivers/spi/spi.c spi_register_board_info
384	!Edrivers/spi/spi.c
385	  </chapter>
386	
387	  <chapter id="i2c">
388	     <title>I<superscript>2</superscript>C and SMBus Subsystem</title>
389	
390	     <para>
391		I<superscript>2</superscript>C (or without fancy typography, "I2C")
392		is an acronym for the "Inter-IC" bus, a simple bus protocol which is
393		widely used where low data rate communications suffice.
394		Since it's also a licensed trademark, some vendors use another
395		name (such as "Two-Wire Interface", TWI) for the same bus.
396		I2C only needs two signals (SCL for clock, SDA for data), conserving
397		board real estate and minimizing signal quality issues.
398		Most I2C devices use seven bit addresses, and bus speeds of up
399		to 400 kHz; there's a high speed extension (3.4 MHz) that's not yet
400		found wide use.
401		I2C is a multi-master bus; open drain signaling is used to
402		arbitrate between masters, as well as to handshake and to
403		synchronize clocks from slower clients.
404	     </para>
405	
406	     <para>
407		The Linux I2C programming interfaces support only the master
408		side of bus interactions, not the slave side.
409		The programming interface is structured around two kinds of driver,
410		and two kinds of device.
411		An I2C "Adapter Driver" abstracts the controller hardware; it binds
412		to a physical device (perhaps a PCI device or platform_device) and
413		exposes a <structname>struct i2c_adapter</structname> representing
414		each I2C bus segment it manages.
415		On each I2C bus segment will be I2C devices represented by a
416		<structname>struct i2c_client</structname>.  Those devices will
417		be bound to a <structname>struct i2c_driver</structname>,
418		which should follow the standard Linux driver model.
419		(At this writing, a legacy model is more widely used.)
420		There are functions to perform various I2C protocol operations; at
421		this writing all such functions are usable only from task context.
422	     </para>
423	
424	     <para>
425		The System Management Bus (SMBus) is a sibling protocol.  Most SMBus
426		systems are also I2C conformant.  The electrical constraints are
427		tighter for SMBus, and it standardizes particular protocol messages
428		and idioms.  Controllers that support I2C can also support most
429		SMBus operations, but SMBus controllers don't support all the protocol
430		options that an I2C controller will.
431		There are functions to perform various SMBus protocol operations,
432		either using I2C primitives or by issuing SMBus commands to
433		i2c_adapter devices which don't support those I2C operations.
434	     </para>
435	
436	!Iinclude/linux/i2c.h
437	!Fdrivers/i2c/i2c-boardinfo.c i2c_register_board_info
438	!Edrivers/i2c/i2c-core.c
439	  </chapter>
440	
441	  <chapter id="hsi">
442	     <title>High Speed Synchronous Serial Interface (HSI)</title>
443	
444	     <para>
445		High Speed Synchronous Serial Interface (HSI) is a
446		serial interface mainly used for connecting application
447		engines (APE) with cellular modem engines (CMT) in cellular
448		handsets.
449	
450		HSI provides multiplexing for up to 16 logical channels,
451		low-latency and full duplex communication.
452	     </para>
453	
454	!Iinclude/linux/hsi/hsi.h
455	!Edrivers/hsi/hsi.c
456	  </chapter>
457	
458	</book>
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.