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- /* bcm2835.h
-
- C and C++ support for Broadcom BCM 2835 as used in Raspberry Pi
-
- Author: Mike McCauley
- Copyright (C) 2011-2013 Mike McCauley
- $Id: bcm2835.h,v 1.20 2015/03/31 04:55:41 mikem Exp mikem $
- */
-
- /*! \defgroup BCM2835grp C library for Broadcom BCM 2835 as used in Raspberry Pi
- \ingroup internals
-
- This is a C library for Raspberry Pi (RPi). It provides access to
- GPIO and other IO functions on the Broadcom BCM 2835 chip,
- allowing access to the GPIO pins on the
- 26 pin IDE plug on the RPi board so you can control and interface with various external devices.
-
- It provides functions for reading digital inputs and setting digital outputs, using SPI and I2C,
- and for accessing the system timers.
- Pin event detection is supported by polling (interrupts are not supported).
-
- It is C++ compatible, and installs as a header file and non-shared library on
- any Linux-based distro (but clearly is no use except on Raspberry Pi or another board with
- BCM 2835).
-
- The version of the package that this documentation refers to can be downloaded
- from http://www.airspayce.com/mikem/bcm2835/bcm2835-1.50.tar.gz
- You can find the latest version at http://www.airspayce.com/mikem/bcm2835
-
- Several example programs are provided.
-
- Based on data in http://elinux.org/RPi_Low-level_peripherals and
- http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
- and http://www.scribd.com/doc/101830961/GPIO-Pads-Control2
-
- You can also find online help and discussion at http://groups.google.com/group/bcm2835
- Please use that group for all questions and discussions on this topic.
- Do not contact the author directly, unless it is to discuss commercial licensing.
- Before asking a question or reporting a bug, please read http://www.catb.org/esr/faqs/smart-questions.html
-
- Tested on debian6-19-04-2012, 2012-07-15-wheezy-raspbian, 2013-07-26-wheezy-raspbian
- and Occidentalisv01, 2016-02-09 Raspbian Jessie.
- CAUTION: it has been observed that when detect enables such as bcm2835_gpio_len()
- are used and the pin is pulled LOW
- it can cause temporary hangs on 2012-07-15-wheezy-raspbian, 2013-07-26-wheezy-raspbian
- and Occidentalisv01.
- Reason for this is not yet determined, but we suspect that an interrupt handler is
- hitting a hard loop on those OSs.
- If you must use bcm2835_gpio_len() and friends, make sure you disable the pins with
- bcm2835_gpio_clr_len() and friends after use.
-
- \par Running as root
-
- Prior to the release of Raspbian Jessie in Feb 2016, access to any
- peripheral device via /dev/mem on the RPi required the process to
- run as root. Raspbian Jessie permits non-root users to access the
- GPIO peripheral (only) via /dev/gpiomem, and this library supports
- that limited mode of operation.
-
- If the library runs with effective UID of 0 (ie root), then
- bcm2835_init() will attempt to open /dev/mem, and, if successful, it
- will permit use of all peripherals and library functions.
-
- If the library runs with any other effective UID (ie not root), then
- bcm2835_init() will attempt to open /dev/gpiomem, and, if
- successful, will only permit GPIO operations. In particular,
- bcm2835_spi_begin() and bcm2835_i2c_begin() will return false and all
- other non-gpio operations may fail silently or crash.
-
- \par Installation
-
- This library consists of a single non-shared library and header file, which will be
- installed in the usual places by make install
-
- \code
- # download the latest version of the library, say bcm2835-1.xx.tar.gz, then:
- tar zxvf bcm2835-1.xx.tar.gz
- cd bcm2835-1.xx
- ./configure
- make
- sudo make check
- sudo make install
- \endcode
-
- \par Physical Addresses
-
- The functions bcm2835_peri_read(), bcm2835_peri_write() and bcm2835_peri_set_bits()
- are low level peripheral register access functions. They are designed to use
- physical addresses as described in section 1.2.3 ARM physical addresses
- of the BCM2835 ARM Peripherals manual.
- Physical addresses range from 0x20000000 to 0x20FFFFFF for peripherals. The bus
- addresses for peripherals are set up to map onto the peripheral bus address range starting at
- 0x7E000000. Thus a peripheral advertised in the manual at bus address 0x7Ennnnnn is available at
- physical address 0x20nnnnnn.
-
- On RPI 2, the peripheral addresses are different and the bcm2835 library gets them
- from reading /proc/device-tree/soc/ranges. This is only availble with recent versions of the kernel on RPI 2.
-
- After initialisation, the base address of the various peripheral
- registers are available with the following
- externals:
- bcm2835_gpio
- bcm2835_pwm
- bcm2835_clk
- bcm2835_pads
- bcm2835_spio0
- bcm2835_st
- bcm2835_bsc0
- bcm2835_bsc1
-
- \par Raspberry Pi 2 (RPI2)
-
- For this library to work correctly on RPI2, you MUST have the device tree support enabled in the kernel.
- You should also ensure you are using the latest version of Linux. The library has been tested on RPI2
- with 2015-02-16-raspbian-wheezy and ArchLinuxARM-rpi-2 as of 2015-03-29.
-
- When device tree suport is enabled, the file /proc/device-tree/soc/ranges will appear in the file system,
- and the bcm2835 module relies on its presence to correctly run on RPI2 (it is optional for RPI1).
- Without device tree support enabled and the presence of this file, it will not work on RPI2.
-
- To enable device tree support:
-
- \code
- sudo raspi-config
- under Advanced Options - enable Device Tree
- Reboot.
- \endcode
-
- \par Pin Numbering
-
- The GPIO pin numbering as used by RPi is different to and inconsistent with the underlying
- BCM 2835 chip pin numbering. http://elinux.org/RPi_BCM2835_GPIOs
-
- RPi has a 26 pin IDE header that provides access to some of the GPIO pins on the BCM 2835,
- as well as power and ground pins. Not all GPIO pins on the BCM 2835 are available on the
- IDE header.
-
- RPi Version 2 also has a P5 connector with 4 GPIO pins, 5V, 3.3V and Gnd.
-
- The functions in this library are designed to be passed the BCM 2835 GPIO pin number and _not_
- the RPi pin number. There are symbolic definitions for each of the available pins
- that you should use for convenience. See \ref RPiGPIOPin.
-
- \par SPI Pins
-
- The bcm2835_spi_* functions allow you to control the BCM 2835 SPI0 interface,
- allowing you to send and received data by SPI (Serial Peripheral Interface).
- For more information about SPI, see http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus
-
- When bcm2835_spi_begin() is called it changes the bahaviour of the SPI interface pins from their
- default GPIO behaviour in order to support SPI. While SPI is in use, you will not be able
- to control the state of the SPI pins through the usual bcm2835_spi_gpio_write().
- When bcm2835_spi_end() is called, the SPI pins will all revert to inputs, and can then be
- configured and controled with the usual bcm2835_gpio_* calls.
-
- The Raspberry Pi GPIO pins used for SPI are:
-
- - P1-19 (MOSI)
- - P1-21 (MISO)
- - P1-23 (CLK)
- - P1-24 (CE0)
- - P1-26 (CE1)
-
- \par I2C Pins
-
- The bcm2835_i2c_* functions allow you to control the BCM 2835 BSC interface,
- allowing you to send and received data by I2C ("eye-squared cee"; generically referred to as "two-wire interface") .
- For more information about I?C, see http://en.wikipedia.org/wiki/I%C2%B2C
-
- The Raspberry Pi V2 GPIO pins used for I2C are:
-
- - P1-03 (SDA)
- - P1-05 (SLC)
-
- \par PWM
-
- The BCM2835 supports hardware PWM on a limited subset of GPIO pins. This bcm2835 library provides
- functions for configuring and controlling PWM output on these pins.
-
- The BCM2835 contains 2 independent PWM channels (0 and 1), each of which be connnected to a limited subset of
- GPIO pins. The following GPIO pins may be connected to the following PWM channels (from section 9.5):
- \code
- GPIO PIN RPi pin PWM Channel ALT FUN
- 12 0 0
- 13 1 0
- 18 1-12 0 5
- 19 1 5
- 40 0 0
- 41 1 0
- 45 1 0
- 52 0 1
- 53 1 1
- \endcode
- In order for a GPIO pin to emit output from its PWM channel, it must be set to the Alt Function given above.
- Note carefully that current versions of the Raspberry Pi only expose one of these pins (GPIO 18 = RPi Pin 1-12)
- on the IO headers, and therefore this is the only IO pin on the RPi that can be used for PWM.
- Further it must be set to ALT FUN 5 to get PWM output.
-
- Both PWM channels are driven by the same PWM clock, whose clock dvider can be varied using
- bcm2835_pwm_set_clock(). Each channel can be separately enabled with bcm2835_pwm_set_mode().
- The average output of the PWM channel is determined by the ratio of DATA/RANGE for that channel.
- Use bcm2835_pwm_set_range() to set the range and bcm2835_pwm_set_data() to set the data in that ratio
-
- Each PWM channel can run in either Balanced or Mark-Space mode. In Balanced mode, the hardware
- sends a combination of clock pulses that results in an overall DATA pulses per RANGE pulses.
- In Mark-Space mode, the hardware sets the output HIGH for DATA clock pulses wide, followed by
- LOW for RANGE-DATA clock pulses.
-
- The PWM clock can be set to control the PWM pulse widths. The PWM clock is derived from
- a 19.2MHz clock. You can set any divider, but some common ones are provided by the BCM2835_PWM_CLOCK_DIVIDER_*
- values of \ref bcm2835PWMClockDivider.
-
- For example, say you wanted to drive a DC motor with PWM at about 1kHz,
- and control the speed in 1/1024 increments from
- 0/1024 (stopped) through to 1024/1024 (full on). In that case you might set the
- clock divider to be 16, and the RANGE to 1024. The pulse repetition frequency will be
- 1.2MHz/1024 = 1171.875Hz.
-
- \par SPI
-
- In order for bcm2835 library SPI to work, you may need to disable the SPI kernel module using:
-
- \code
- sudo raspi-config
- under Advanced Options - enable Device Tree
- under Advanced Options - disable SPI
- Reboot.
- \endcode
-
- \par Real Time performance constraints
-
- The bcm2835 is a library for user programs (i.e. they run in 'userland').
- Such programs are not part of the kernel and are usually
- subject to paging and swapping by the kernel while it does other things besides running your program.
- This means that you should not expect to get real-time performance or
- real-time timing constraints from such programs. In particular, there is no guarantee that the
- bcm2835_delay() and bcm2835_delayMicroseconds() will return after exactly the time requested.
- In fact, depending on other activity on the host, IO etc, you might get significantly longer delay times
- than the one you asked for. So please dont expect to get exactly the time delay you request.
-
- Arjan reports that you can prevent swapping on Linux with the following code fragment:
-
- \code
- struct sched_param sp;
- memset(&sp, 0, sizeof(sp));
- sp.sched_priority = sched_get_priority_max(SCHED_FIFO);
- sched_setscheduler(0, SCHED_FIFO, &sp);
- mlockall(MCL_CURRENT | MCL_FUTURE);
- \endcode
-
- \par Bindings to other languages
-
- mikem has made Perl bindings available at CPAN:
- http://search.cpan.org/~mikem/Device-BCM2835-1.9/lib/Device/BCM2835.pm
- Matthew Baker has kindly made Python bindings available at:
- https: github.com/mubeta06/py-libbcm2835
- Gary Marks has created a Serial Peripheral Interface (SPI) command-line utility
- for Raspberry Pi, based on the bcm2835 library. The
- utility, spincl, is licensed under Open Source GNU GPLv3 by iP Solutions (http://ipsolutionscorp.com), as a
- free download with source included: http://ipsolutionscorp.com/raspberry-pi-spi-utility/
-
- \par Open Source Licensing GPL V2
-
- This is the appropriate option if you want to share the source code of your
- application with everyone you distribute it to, and you also want to give them
- the right to share who uses it. If you wish to use this software under Open
- Source Licensing, you must contribute all your source code to the open source
- community in accordance with the GPL Version 2 when your application is
- distributed. See http://www.gnu.org/copyleft/gpl.html and COPYING
-
- \par Acknowledgements
-
- Some of this code has been inspired by Dom and Gert.
- The I2C code has been inspired by Alan Barr.
-
- \par Revision History
-
- \version 1.0 Initial release
-
- \version 1.1 Minor bug fixes
-
- \version 1.2 Added support for SPI
-
- \version 1.3 Added bcm2835_spi_transfern()
-
- \version 1.4 Fixed a problem that prevented SPI CE1 being used. Reported by David Robinson.
-
- \version 1.5 Added bcm2835_close() to deinit the library. Suggested by C?sar Ortiz
-
- \version 1.6 Document testing on 2012-07-15-wheezy-raspbian and Occidentalisv01
- Functions bcm2835_gpio_ren(), bcm2835_gpio_fen(), bcm2835_gpio_hen()
- bcm2835_gpio_len(), bcm2835_gpio_aren() and bcm2835_gpio_afen() now
- changes only the pin specified. Other pins that were already previously
- enabled stay enabled.
- Added bcm2835_gpio_clr_ren(), bcm2835_gpio_clr_fen(), bcm2835_gpio_clr_hen()
- bcm2835_gpio_clr_len(), bcm2835_gpio_clr_aren(), bcm2835_gpio_clr_afen()
- to clear the enable for individual pins, suggested by Andreas Sundstrom.
-
- \version 1.7 Added bcm2835_spi_transfernb to support different buffers for read and write.
-
- \version 1.8 Improvements to read barrier, as suggested by maddin.
-
- \version 1.9 Improvements contributed by mikew:
- I noticed that it was mallocing memory for the mmaps on /dev/mem.
- It's not necessary to do that, you can just mmap the file directly,
- so I've removed the mallocs (and frees).
- I've also modified delayMicroseconds() to use nanosleep() for long waits,
- and a busy wait on a high resolution timer for the rest. This is because
- I've found that calling nanosleep() takes at least 100-200 us.
- You need to link using '-lrt' using this version.
- I've added some unsigned casts to the debug prints to silence compiler
- warnings I was getting, fixed some typos, and changed the value of
- BCM2835_PAD_HYSTERESIS_ENABLED to 0x08 as per Gert van Loo's doc at
- http://www.scribd.com/doc/101830961/GPIO-Pads-Control2
- Also added a define for the passwrd value that Gert says is needed to
- change pad control settings.
-
- \version 1.10 Changed the names of the delay functions to bcm2835_delay()
- and bcm2835_delayMicroseconds() to prevent collisions with wiringPi.
- Macros to map delay()-> bcm2835_delay() and
- Macros to map delayMicroseconds()-> bcm2835_delayMicroseconds(), which
- can be disabled by defining BCM2835_NO_DELAY_COMPATIBILITY
-
- \version 1.11 Fixed incorrect link to download file
-
- \version 1.12 New GPIO pin definitions for RPi version 2 (which has a different GPIO mapping)
-
- \version 1.13 New GPIO pin definitions for RPi version 2 plug P5
- Hardware base pointers are now available (after initialisation) externally as bcm2835_gpio
- bcm2835_pwm bcm2835_clk bcm2835_pads bcm2835_spi0.
-
- \version 1.14 Now compiles even if CLOCK_MONOTONIC_RAW is not available, uses CLOCK_MONOTONIC instead.
- Fixed errors in documentation of SPI divider frequencies based on 250MHz clock.
- Reported by Ben Simpson.
-
- \version 1.15 Added bcm2835_close() to end of examples as suggested by Mark Wolfe.
-
- \version 1.16 Added bcm2835_gpio_set_multi, bcm2835_gpio_clr_multi and bcm2835_gpio_write_multi
- to allow a mask of pins to be set all at once. Requested by Sebastian Loncar.
-
- \version 1.17 Added bcm2835_gpio_write_mask. Requested by Sebastian Loncar.
-
- \version 1.18 Added bcm2835_i2c_* functions. Changes to bcm2835_delayMicroseconds:
- now uses the RPi system timer counter, instead of clock_gettime, for improved accuracy.
- No need to link with -lrt now. Contributed by Arjan van Vught.
- \version 1.19 Removed inlines added by previous patch since they don't seem to work everywhere.
- Reported by olly.
-
- \version 1.20 Patch from Mark Dootson to close /dev/mem after access to the peripherals has been granted.
-
- \version 1.21 delayMicroseconds is now not susceptible to 32 bit timer overruns.
- Patch courtesy Jeremy Mortis.
-
- \version 1.22 Fixed incorrect definition of BCM2835_GPFEN0 which broke the ability to set
- falling edge events. Reported by Mark Dootson.
-
- \version 1.23 Added bcm2835_i2c_set_baudrate and bcm2835_i2c_read_register_rs.
- Improvements to bcm2835_i2c_read and bcm2835_i2c_write functions
- to fix ocasional reads not completing. Patched by Mark Dootson.
-
- \version 1.24 Mark Dootson p[atched a problem with his previously submitted code
- under high load from other processes.
-
- \version 1.25 Updated author and distribution location details to airspayce.com
-
- \version 1.26 Added missing unmapmem for pads in bcm2835_close to prevent a memory leak.
- Reported by Hartmut Henkel.
-
- \version 1.27 bcm2835_gpio_set_pad() no longer needs BCM2835_PAD_PASSWRD: it is
- now automatically included.
- Added suport for PWM mode with bcm2835_pwm_* functions.
-
- \version 1.28 Fixed a problem where bcm2835_spi_writenb() would have problems with transfers of more than
- 64 bytes dues to read buffer filling. Patched by Peter Würtz.
-
- \version 1.29 Further fix to SPI from Peter Würtz.
-
- \version 1.30 10 microsecond delays from bcm2835_spi_transfer and bcm2835_spi_transfern for
- significant performance improvements, Patch by Alan Watson.
-
- \version 1.31 Fix a GCC warning about dummy variable, patched by Alan Watson. Thanks.
-
- \version 1.32 Added option I2C_V1 definition to compile for version 1 RPi.
- By default I2C code is generated for the V2 RPi which has SDA1 and SCL1 connected.
- Contributed by Malcolm Wiles based on work by Arvi Govindaraj.
-
- \version 1.33 Added command line utilities i2c and gpio to examples. Contributed by Shahrooz Shahparnia.
-
- \version 1.34 Added bcm2835_i2c_write_read_rs() which writes an arbitrary number of bytes,
- sends a repeat start, and reads from the device. Contributed by Eduardo Steinhorst.
-
- \version 1.35 Fix build errors when compiled under Qt. Also performance improvements with SPI transfers. Contributed b Udo Klaas.
-
- \version 1.36 Make automake's test runner detect that we're skipping tests when not root, the second
- one makes us skip the test when using fakeroot (as used when building
- Debian packages). Contributed by Guido Günther.
-
- \version 1.37 Moved confiure.in to configure.ac as receommnded by autoreconf.<br>
- Improvements to bcm2835_st_read to account for possible timer overflow, contributed by 'Ed'.<br>
- Added definitions for Raspberry Pi B+ J8 header GPIO pins.<br>
-
- \version 1.38 Added bcm2835_regbase for the benefit of C# wrappers, patch by Frank Hommers <br>
-
- \version 1.39 Beta version of RPi2 compatibility. Not tested here on RPi2 hardware.
- Testers please confirm correct operation on RPi2.<br>
- Unneccessary 'volatile' qualifiers removed from all variables and signatures.<br>
- Removed unsupportable PWM dividers, based on a report from Christophe Cecillon.<br>
- Minor improvements to spi.c example.<br>
-
- \version 1.40 Correct operation on RPi2 has been confirmed.<br>
- Fixed a number of compiler errors and warnings that occur when bcm2835.h is included
- in code compiled with -Wall -Woverflow -Wstrict-overflow -Wshadow -Wextra -pedantic.
- Reported by tlhackque.<br>
- Fixed a problem where calling bcm2835_delayMicroseconds loops forever when debug is set. Reported by tlhackque.<br>
- Reinstated use of volatile in 2 functions where there was a danger of lost reads or writes. Reported by tlhackque.<br>
-
- \version 1.41 Added BCM2835_VERSION macro and new function bcm2835_version(); Requested by tlhackque.<br>
- Improvements to peripheral memory barriers as suggested by tlhackque.<br>
- Reinstated some necessary volatile declarations as requested by tlhackque.<br>
-
- \version 1.42 Further improvements to memory barriers with the patient assistance and patches of tlhackque.<br>
-
- \version 1.43 Fixed problems with compiling barriers on RPI 2 with Arch Linux and gcc 4.9.2.
- Reported and patched by Lars Christensen.<br>
- Testing on RPI 2, with ArchLinuxARM-rpi-2-latest and 2015-02-16-raspbian-wheezy.<br>
-
- \version 1.44 Added documention about the need for device tree to be enabled on RPI2.<br>
- Improvements to detection of availablity of DMB instruction based on value of __ARM_ARCH macro.<br>
-
- \version 1.45 Fixed an error in the pad group offsets that would prevent bcm2835_gpio_set_pad()
- and bcm2835_gpio_pad() working correctly with non-0 pad groups. Reported by Guido.
-
- \version 1.46 2015-09-18
- Added symbolic definitions for remaining pins on 40 pin GPIO header on RPi 2. <br>
-
- \version 1.47 2015-11-18
- Fixed possibly incorrect reads in bcm2835_i2c_read_register_rs, patch from Eckhardt Ulrich.<br>
-
- \version 1.48 2015-12-08
- Added patch from Eckhardt Ulrich that fixed problems that could cause hanging with bcm2835_i2c_read_register_rs
- and others.
-
- \version 1.49 2016-01-05
- Added patch from Jonathan Perkin with new functions bcm2835_gpio_eds_multi() and bcm2835_gpio_set_eds_multi().
-
- \version 1.50 2016-02-28
- Added support for running as non-root, permitting access to GPIO only. Functions
- bcm2835_spi_begin() and bcm2835_i2c_begin() will now return 0 if not running as root
- (which prevents access to the SPI and I2C peripherals, amongst others).
- Testing on Raspbian Jessie.
-
- \author Mike McCauley (mikem@airspayce.com) DO NOT CONTACT THE AUTHOR DIRECTLY: USE THE LISTS
-
-
- Modified September 2016 by Marcelo Aquino <marceloaqno@gmail.org>
- */
-
-
- /* Defines for BCM2835 */
- #ifndef BCM2835_H
- #define BCM2835_H
-
- #include <stdint.h>
-
- #define BCM2835_VERSION 10050 /* Version 1.50 */
-
- /* RPi 2 is ARM v7, and has DMB instruction for memory barriers.
- Older RPis are ARM v6 and don't, so a coprocessor instruction must be used instead.
- However, not all versions of gcc in all distros support the dmb assembler instruction even on conmpatible processors.
- This test is so any ARMv7 or higher processors with suitable GCC will use DMB.
- */
- #if __ARM_ARCH >= 7
- #define BCM2835_HAVE_DMB
- #endif
-
- /*! \defgroup BCM2835constantsgrp Constants for passing to and from library functions
- \ingroup BCM2835grp
- The values here are designed to be passed to various functions in the bcm2835 library.
- @{
- */
-
- /*! This means pin HIGH, true, 3.3volts on a pin. */
- #define HIGH 0x1
- /*! This means pin LOW, false, 0volts on a pin. */
- #define LOW 0x0
-
- /*! Speed of the core clock core_clk */
- #define BCM2835_CORE_CLK_HZ 250000000 /*!< 250 MHz */
-
- /*! On RPi2 with BCM2836, and all recent OSs, the base of the peripherals is read from a /proc file */
- #define BMC2835_RPI2_DT_FILENAME "/proc/device-tree/soc/ranges"
- /*! Offset into BMC2835_RPI2_DT_FILENAME for the peripherals base address */
- #define BMC2835_RPI2_DT_PERI_BASE_ADDRESS_OFFSET 4
- /*! Offset into BMC2835_RPI2_DT_FILENAME for the peripherals size address */
- #define BMC2835_RPI2_DT_PERI_SIZE_OFFSET 8
-
- /*! Physical addresses for various peripheral register sets
- Base Physical Address of the BCM 2835 peripheral registers
- Note this is different for the RPi2 BCM2836, where this is derived from /proc/device-tree/soc/ranges
- If /proc/device-tree/soc/ranges exists on a RPi 1 OS, it would be expected to contain the
- following numbers:
- */
- /*! Peripherals block base address on RPi 1 */
- #define BCM2835_PERI_BASE 0x20000000
- /*! Size of the peripherals block on RPi 1 */
- #define BCM2835_PERI_SIZE 0x01000000
-
- /*! Offsets for the bases of various peripherals within the peripherals block
- / Base Address of the System Timer registers
- */
- #define BCM2835_ST_BASE 0x3000
- /*! Base Address of the Pads registers */
- #define BCM2835_GPIO_PADS 0x100000
- /*! Base Address of the Clock/timer registers */
- #define BCM2835_CLOCK_BASE 0x101000
- /*! Base Address of the GPIO registers */
- #define BCM2835_GPIO_BASE 0x200000
- /*! Base Address of the SPI0 registers */
- #define BCM2835_SPI0_BASE 0x204000
- /*! Base Address of the BSC0 registers */
- #define BCM2835_BSC0_BASE 0x205000
- /*! Base Address of the PWM registers */
- #define BCM2835_GPIO_PWM 0x20C000
- /*! Base Address of the BSC1 registers */
- #define BCM2835_BSC1_BASE 0x804000
-
- /*! Physical address and size of the peripherals block
- May be overridden on RPi2
- */
- extern uint32_t *bcm2835_peripherals_base;
- /*! Size of the peripherals block to be mapped */
- extern uint32_t bcm2835_peripherals_size;
-
- /*! Virtual memory address of the mapped peripherals block */
- extern uint32_t *bcm2835_peripherals;
-
- /*! Base of the ST (System Timer) registers.
- Available after bcm2835_init has been called (as root)
- */
- extern volatile uint32_t *bcm2835_st;
-
- /*! Base of the GPIO registers.
- Available after bcm2835_init has been called
- */
- extern volatile uint32_t *bcm2835_gpio;
-
- /*! Base of the PWM registers.
- Available after bcm2835_init has been called (as root)
- */
- extern volatile uint32_t *bcm2835_pwm;
-
- /*! Base of the CLK registers.
- Available after bcm2835_init has been called (as root)
- */
- extern volatile uint32_t *bcm2835_clk;
-
- /*! Base of the PADS registers.
- Available after bcm2835_init has been called (as root)
- */
- extern volatile uint32_t *bcm2835_pads;
-
- /*! Base of the SPI0 registers.
- Available after bcm2835_init has been called (as root)
- */
- extern volatile uint32_t *bcm2835_spi0;
-
- /*! Base of the BSC0 registers.
- Available after bcm2835_init has been called (as root)
- */
- extern volatile uint32_t *bcm2835_bsc0;
-
- /*! Base of the BSC1 registers.
- Available after bcm2835_init has been called (as root)
- */
- extern volatile uint32_t *bcm2835_bsc1;
-
- /*! \brief bcm2835RegisterBase
- Register bases for bcm2835_regbase()
- */
- typedef enum {
- BCM2835_REGBASE_ST = 1, /*!< Base of the ST (System Timer) registers. */
- BCM2835_REGBASE_GPIO = 2, /*!< Base of the GPIO registers. */
- BCM2835_REGBASE_PWM = 3, /*!< Base of the PWM registers. */
- BCM2835_REGBASE_CLK = 4, /*!< Base of the CLK registers. */
- BCM2835_REGBASE_PADS = 5, /*!< Base of the PADS registers. */
- BCM2835_REGBASE_SPI0 = 6, /*!< Base of the SPI0 registers. */
- BCM2835_REGBASE_BSC0 = 7, /*!< Base of the BSC0 registers. */
- BCM2835_REGBASE_BSC1 = 8 /*!< Base of the BSC1 registers. */
- } bcm2835RegisterBase;
-
- /*! Size of memory page on RPi */
- #define BCM2835_PAGE_SIZE (4*1024)
- /*! Size of memory block on RPi */
- #define BCM2835_BLOCK_SIZE (4*1024)
-
-
- /* Defines for GPIO
- The BCM2835 has 54 GPIO pins.
- BCM2835 data sheet, Page 90 onwards.
- */
- /*! GPIO register offsets from BCM2835_GPIO_BASE.
- Offsets into the GPIO Peripheral block in bytes per 6.1 Register View
- */
- #define BCM2835_GPFSEL0 0x0000 /*!< GPIO Function Select 0 */
- #define BCM2835_GPFSEL1 0x0004 /*!< GPIO Function Select 1 */
- #define BCM2835_GPFSEL2 0x0008 /*!< GPIO Function Select 2 */
- #define BCM2835_GPFSEL3 0x000c /*!< GPIO Function Select 3 */
- #define BCM2835_GPFSEL4 0x0010 /*!< GPIO Function Select 4 */
- #define BCM2835_GPFSEL5 0x0014 /*!< GPIO Function Select 5 */
- #define BCM2835_GPSET0 0x001c /*!< GPIO Pin Output Set 0 */
- #define BCM2835_GPSET1 0x0020 /*!< GPIO Pin Output Set 1 */
- #define BCM2835_GPCLR0 0x0028 /*!< GPIO Pin Output Clear 0 */
- #define BCM2835_GPCLR1 0x002c /*!< GPIO Pin Output Clear 1 */
- #define BCM2835_GPLEV0 0x0034 /*!< GPIO Pin Level 0 */
- #define BCM2835_GPLEV1 0x0038 /*!< GPIO Pin Level 1 */
- #define BCM2835_GPEDS0 0x0040 /*!< GPIO Pin Event Detect Status 0 */
- #define BCM2835_GPEDS1 0x0044 /*!< GPIO Pin Event Detect Status 1 */
- #define BCM2835_GPREN0 0x004c /*!< GPIO Pin Rising Edge Detect Enable 0 */
- #define BCM2835_GPREN1 0x0050 /*!< GPIO Pin Rising Edge Detect Enable 1 */
- #define BCM2835_GPFEN0 0x0058 /*!< GPIO Pin Falling Edge Detect Enable 0 */
- #define BCM2835_GPFEN1 0x005c /*!< GPIO Pin Falling Edge Detect Enable 1 */
- #define BCM2835_GPHEN0 0x0064 /*!< GPIO Pin High Detect Enable 0 */
- #define BCM2835_GPHEN1 0x0068 /*!< GPIO Pin High Detect Enable 1 */
- #define BCM2835_GPLEN0 0x0070 /*!< GPIO Pin Low Detect Enable 0 */
- #define BCM2835_GPLEN1 0x0074 /*!< GPIO Pin Low Detect Enable 1 */
- #define BCM2835_GPAREN0 0x007c /*!< GPIO Pin Async. Rising Edge Detect 0 */
- #define BCM2835_GPAREN1 0x0080 /*!< GPIO Pin Async. Rising Edge Detect 1 */
- #define BCM2835_GPAFEN0 0x0088 /*!< GPIO Pin Async. Falling Edge Detect 0 */
- #define BCM2835_GPAFEN1 0x008c /*!< GPIO Pin Async. Falling Edge Detect 1 */
- #define BCM2835_GPPUD 0x0094 /*!< GPIO Pin Pull-up/down Enable */
- #define BCM2835_GPPUDCLK0 0x0098 /*!< GPIO Pin Pull-up/down Enable Clock 0 */
- #define BCM2835_GPPUDCLK1 0x009c /*!< GPIO Pin Pull-up/down Enable Clock 1 */
-
- /*! \brief bcm2835PortFunction
- Port function select modes for bcm2835_gpio_fsel()
- */
- typedef enum {
- BCM2835_GPIO_FSEL_INPT = 0x00, /*!< Input 0b000 */
- BCM2835_GPIO_FSEL_OUTP = 0x01, /*!< Output 0b001 */
- BCM2835_GPIO_FSEL_ALT0 = 0x04, /*!< Alternate function 0 0b100 */
- BCM2835_GPIO_FSEL_ALT1 = 0x05, /*!< Alternate function 1 0b101 */
- BCM2835_GPIO_FSEL_ALT2 = 0x06, /*!< Alternate function 2 0b110, */
- BCM2835_GPIO_FSEL_ALT3 = 0x07, /*!< Alternate function 3 0b111 */
- BCM2835_GPIO_FSEL_ALT4 = 0x03, /*!< Alternate function 4 0b011 */
- BCM2835_GPIO_FSEL_ALT5 = 0x02, /*!< Alternate function 5 0b010 */
- BCM2835_GPIO_FSEL_MASK = 0x07 /*!< Function select bits mask 0b111 */
- } bcm2835FunctionSelect;
-
- /*! \brief bcm2835PUDControl
- Pullup/Pulldown defines for bcm2835_gpio_pud()
- */
- typedef enum {
- BCM2835_GPIO_PUD_OFF = 0x00, /*!< Off ? disable pull-up/down 0b00 */
- BCM2835_GPIO_PUD_DOWN = 0x01, /*!< Enable Pull Down control 0b01 */
- BCM2835_GPIO_PUD_UP = 0x02 /*!< Enable Pull Up control 0b10 */
- } bcm2835PUDControl;
-
- /*! Pad control register offsets from BCM2835_GPIO_PADS */
- #define BCM2835_PADS_GPIO_0_27 0x002c /*!< Pad control register for pads 0 to 27 */
- #define BCM2835_PADS_GPIO_28_45 0x0030 /*!< Pad control register for pads 28 to 45 */
- #define BCM2835_PADS_GPIO_46_53 0x0034 /*!< Pad control register for pads 46 to 53 */
-
- /*! Pad Control masks */
- #define BCM2835_PAD_PASSWRD (0x5A << 24) /*!< Password to enable setting pad mask */
- #define BCM2835_PAD_SLEW_RATE_UNLIMITED 0x10 /*!< Slew rate unlimited */
- #define BCM2835_PAD_HYSTERESIS_ENABLED 0x08 /*!< Hysteresis enabled */
- #define BCM2835_PAD_DRIVE_2mA 0x00 /*!< 2mA drive current */
- #define BCM2835_PAD_DRIVE_4mA 0x01 /*!< 4mA drive current */
- #define BCM2835_PAD_DRIVE_6mA 0x02 /*!< 6mA drive current */
- #define BCM2835_PAD_DRIVE_8mA 0x03 /*!< 8mA drive current */
- #define BCM2835_PAD_DRIVE_10mA 0x04 /*!< 10mA drive current */
- #define BCM2835_PAD_DRIVE_12mA 0x05 /*!< 12mA drive current */
- #define BCM2835_PAD_DRIVE_14mA 0x06 /*!< 14mA drive current */
- #define BCM2835_PAD_DRIVE_16mA 0x07 /*!< 16mA drive current */
-
- /*! \brief bcm2835PadGroup
- Pad group specification for bcm2835_gpio_pad()
- */
- typedef enum {
- BCM2835_PAD_GROUP_GPIO_0_27 = 0, /*!< Pad group for GPIO pads 0 to 27 */
- BCM2835_PAD_GROUP_GPIO_28_45 = 1, /*!< Pad group for GPIO pads 28 to 45 */
- BCM2835_PAD_GROUP_GPIO_46_53 = 2 /*!< Pad group for GPIO pads 46 to 53 */
- } bcm2835PadGroup;
-
- /*! \brief GPIO Pin Numbers
-
- Here we define Raspberry Pin GPIO pins on P1 in terms of the underlying BCM GPIO pin numbers.
- These can be passed as a pin number to any function requiring a pin.
- Not all pins on the RPi 26 bin IDE plug are connected to GPIO pins
- and some can adopt an alternate function.
- RPi version 2 has some slightly different pinouts, and these are values RPI_V2_*.
- RPi B+ has yet differnet pinouts and these are defined in RPI_BPLUS_*.
- At bootup, pins 8 and 10 are set to UART0_TXD, UART0_RXD (ie the alt0 function) respectively
- When SPI0 is in use (ie after bcm2835_spi_begin()), SPI0 pins are dedicated to SPI
- and cant be controlled independently.
- If you are using the RPi Compute Module, just use the GPIO number: there is no need to use one of these
- symbolic names
- */
- typedef enum {
- RPI_GPIO_P1_03 = 0, /*!< Version 1, Pin P1-03 */
- RPI_GPIO_P1_05 = 1, /*!< Version 1, Pin P1-05 */
- RPI_GPIO_P1_07 = 4, /*!< Version 1, Pin P1-07 */
- RPI_GPIO_P1_08 = 14, /*!< Version 1, Pin P1-08, defaults to alt function 0 UART0_TXD */
- RPI_GPIO_P1_10 = 15, /*!< Version 1, Pin P1-10, defaults to alt function 0 UART0_RXD */
- RPI_GPIO_P1_11 = 17, /*!< Version 1, Pin P1-11 */
- RPI_GPIO_P1_12 = 18, /*!< Version 1, Pin P1-12, can be PWM channel 0 in ALT FUN 5 */
- RPI_GPIO_P1_13 = 21, /*!< Version 1, Pin P1-13 */
- RPI_GPIO_P1_15 = 22, /*!< Version 1, Pin P1-15 */
- RPI_GPIO_P1_16 = 23, /*!< Version 1, Pin P1-16 */
- RPI_GPIO_P1_18 = 24, /*!< Version 1, Pin P1-18 */
- RPI_GPIO_P1_19 = 10, /*!< Version 1, Pin P1-19, MOSI when SPI0 in use */
- RPI_GPIO_P1_21 = 9, /*!< Version 1, Pin P1-21, MISO when SPI0 in use */
- RPI_GPIO_P1_22 = 25, /*!< Version 1, Pin P1-22 */
- RPI_GPIO_P1_23 = 11, /*!< Version 1, Pin P1-23, CLK when SPI0 in use */
- RPI_GPIO_P1_24 = 8, /*!< Version 1, Pin P1-24, CE0 when SPI0 in use */
- RPI_GPIO_P1_26 = 7, /*!< Version 1, Pin P1-26, CE1 when SPI0 in use */
-
- /* RPi Version 2 */
- RPI_V2_GPIO_P1_03 = 2, /*!< Version 2, Pin P1-03 */
- RPI_V2_GPIO_P1_05 = 3, /*!< Version 2, Pin P1-05 */
- RPI_V2_GPIO_P1_07 = 4, /*!< Version 2, Pin P1-07 */
- RPI_V2_GPIO_P1_08 = 14, /*!< Version 2, Pin P1-08, defaults to alt function 0 UART0_TXD */
- RPI_V2_GPIO_P1_10 = 15, /*!< Version 2, Pin P1-10, defaults to alt function 0 UART0_RXD */
- RPI_V2_GPIO_P1_11 = 17, /*!< Version 2, Pin P1-11 */
- RPI_V2_GPIO_P1_12 = 18, /*!< Version 2, Pin P1-12, can be PWM channel 0 in ALT FUN 5 */
- RPI_V2_GPIO_P1_13 = 27, /*!< Version 2, Pin P1-13 */
- RPI_V2_GPIO_P1_15 = 22, /*!< Version 2, Pin P1-15 */
- RPI_V2_GPIO_P1_16 = 23, /*!< Version 2, Pin P1-16 */
- RPI_V2_GPIO_P1_18 = 24, /*!< Version 2, Pin P1-18 */
- RPI_V2_GPIO_P1_19 = 10, /*!< Version 2, Pin P1-19, MOSI when SPI0 in use */
- RPI_V2_GPIO_P1_21 = 9, /*!< Version 2, Pin P1-21, MISO when SPI0 in use */
- RPI_V2_GPIO_P1_22 = 25, /*!< Version 2, Pin P1-22 */
- RPI_V2_GPIO_P1_23 = 11, /*!< Version 2, Pin P1-23, CLK when SPI0 in use */
- RPI_V2_GPIO_P1_24 = 8, /*!< Version 2, Pin P1-24, CE0 when SPI0 in use */
- RPI_V2_GPIO_P1_26 = 7, /*!< Version 2, Pin P1-26, CE1 when SPI0 in use */
- RPI_V2_GPIO_P1_29 = 5, /*!< Version 2, Pin P1-29 */
- RPI_V2_GPIO_P1_31 = 6, /*!< Version 2, Pin P1-31 */
- RPI_V2_GPIO_P1_32 = 12, /*!< Version 2, Pin P1-32 */
- RPI_V2_GPIO_P1_33 = 13, /*!< Version 2, Pin P1-33 */
- RPI_V2_GPIO_P1_35 = 19, /*!< Version 2, Pin P1-35 */
- RPI_V2_GPIO_P1_36 = 16, /*!< Version 2, Pin P1-36 */
- RPI_V2_GPIO_P1_37 = 26, /*!< Version 2, Pin P1-37 */
- RPI_V2_GPIO_P1_38 = 20, /*!< Version 2, Pin P1-38 */
- RPI_V2_GPIO_P1_40 = 21, /*!< Version 2, Pin P1-40 */
-
- /* RPi Version 2, new plug P5 */
- RPI_V2_GPIO_P5_03 = 28, /*!< Version 2, Pin P5-03 */
- RPI_V2_GPIO_P5_04 = 29, /*!< Version 2, Pin P5-04 */
- RPI_V2_GPIO_P5_05 = 30, /*!< Version 2, Pin P5-05 */
- RPI_V2_GPIO_P5_06 = 31, /*!< Version 2, Pin P5-06 */
-
- /* RPi B+ J8 header, also RPi 2 40 pin GPIO header */
- RPI_BPLUS_GPIO_J8_03 = 2, /*!< B+, Pin J8-03 */
- RPI_BPLUS_GPIO_J8_05 = 3, /*!< B+, Pin J8-05 */
- RPI_BPLUS_GPIO_J8_07 = 4, /*!< B+, Pin J8-07 */
- RPI_BPLUS_GPIO_J8_08 = 14, /*!< B+, Pin J8-08, defaults to alt function 0 UART0_TXD */
- RPI_BPLUS_GPIO_J8_10 = 15, /*!< B+, Pin J8-10, defaults to alt function 0 UART0_RXD */
- RPI_BPLUS_GPIO_J8_11 = 17, /*!< B+, Pin J8-11 */
- RPI_BPLUS_GPIO_J8_12 = 18, /*!< B+, Pin J8-12, can be PWM channel 0 in ALT FUN 5 */
- RPI_BPLUS_GPIO_J8_13 = 27, /*!< B+, Pin J8-13 */
- RPI_BPLUS_GPIO_J8_15 = 22, /*!< B+, Pin J8-15 */
- RPI_BPLUS_GPIO_J8_16 = 23, /*!< B+, Pin J8-16 */
- RPI_BPLUS_GPIO_J8_18 = 24, /*!< B+, Pin J8-18 */
- RPI_BPLUS_GPIO_J8_19 = 10, /*!< B+, Pin J8-19, MOSI when SPI0 in use */
- RPI_BPLUS_GPIO_J8_21 = 9, /*!< B+, Pin J8-21, MISO when SPI0 in use */
- RPI_BPLUS_GPIO_J8_22 = 25, /*!< B+, Pin J8-22 */
- RPI_BPLUS_GPIO_J8_23 = 11, /*!< B+, Pin J8-23, CLK when SPI0 in use */
- RPI_BPLUS_GPIO_J8_24 = 8, /*!< B+, Pin J8-24, CE0 when SPI0 in use */
- RPI_BPLUS_GPIO_J8_26 = 7, /*!< B+, Pin J8-26, CE1 when SPI0 in use */
- RPI_BPLUS_GPIO_J8_29 = 5, /*!< B+, Pin J8-29, */
- RPI_BPLUS_GPIO_J8_31 = 6, /*!< B+, Pin J8-31, */
- RPI_BPLUS_GPIO_J8_32 = 12, /*!< B+, Pin J8-32, */
- RPI_BPLUS_GPIO_J8_33 = 13, /*!< B+, Pin J8-33, */
- RPI_BPLUS_GPIO_J8_35 = 19, /*!< B+, Pin J8-35, */
- RPI_BPLUS_GPIO_J8_36 = 16, /*!< B+, Pin J8-36, */
- RPI_BPLUS_GPIO_J8_37 = 26, /*!< B+, Pin J8-37, */
- RPI_BPLUS_GPIO_J8_38 = 20, /*!< B+, Pin J8-38, */
- RPI_BPLUS_GPIO_J8_40 = 21 /*!< B+, Pin J8-40, */
- } RPiGPIOPin;
-
- /* Defines for SPI
- GPIO register offsets from BCM2835_SPI0_BASE.
- Offsets into the SPI Peripheral block in bytes per 10.5 SPI Register Map
- */
- #define BCM2835_SPI0_CS 0x0000 /*!< SPI Master Control and Status */
- #define BCM2835_SPI0_FIFO 0x0004 /*!< SPI Master TX and RX FIFOs */
- #define BCM2835_SPI0_CLK 0x0008 /*!< SPI Master Clock Divider */
- #define BCM2835_SPI0_DLEN 0x000c /*!< SPI Master Data Length */
- #define BCM2835_SPI0_LTOH 0x0010 /*!< SPI LOSSI mode TOH */
- #define BCM2835_SPI0_DC 0x0014 /*!< SPI DMA DREQ Controls */
-
- /* Register masks for SPI0_CS */
- #define BCM2835_SPI0_CS_LEN_LONG 0x02000000 /*!< Enable Long data word in Lossi mode if DMA_LEN is set */
- #define BCM2835_SPI0_CS_DMA_LEN 0x01000000 /*!< Enable DMA mode in Lossi mode */
- #define BCM2835_SPI0_CS_CSPOL2 0x00800000 /*!< Chip Select 2 Polarity */
- #define BCM2835_SPI0_CS_CSPOL1 0x00400000 /*!< Chip Select 1 Polarity */
- #define BCM2835_SPI0_CS_CSPOL0 0x00200000 /*!< Chip Select 0 Polarity */
- #define BCM2835_SPI0_CS_RXF 0x00100000 /*!< RXF - RX FIFO Full */
- #define BCM2835_SPI0_CS_RXR 0x00080000 /*!< RXR RX FIFO needs Reading (full) */
- #define BCM2835_SPI0_CS_TXD 0x00040000 /*!< TXD TX FIFO can accept Data */
- #define BCM2835_SPI0_CS_RXD 0x00020000 /*!< RXD RX FIFO contains Data */
- #define BCM2835_SPI0_CS_DONE 0x00010000 /*!< Done transfer Done */
- #define BCM2835_SPI0_CS_TE_EN 0x00008000 /*!< Unused */
- #define BCM2835_SPI0_CS_LMONO 0x00004000 /*!< Unused */
- #define BCM2835_SPI0_CS_LEN 0x00002000 /*!< LEN LoSSI enable */
- #define BCM2835_SPI0_CS_REN 0x00001000 /*!< REN Read Enable */
- #define BCM2835_SPI0_CS_ADCS 0x00000800 /*!< ADCS Automatically Deassert Chip Select */
- #define BCM2835_SPI0_CS_INTR 0x00000400 /*!< INTR Interrupt on RXR */
- #define BCM2835_SPI0_CS_INTD 0x00000200 /*!< INTD Interrupt on Done */
- #define BCM2835_SPI0_CS_DMAEN 0x00000100 /*!< DMAEN DMA Enable */
- #define BCM2835_SPI0_CS_TA 0x00000080 /*!< Transfer Active */
- #define BCM2835_SPI0_CS_CSPOL 0x00000040 /*!< Chip Select Polarity */
- #define BCM2835_SPI0_CS_CLEAR 0x00000030 /*!< Clear FIFO Clear RX and TX */
- #define BCM2835_SPI0_CS_CLEAR_RX 0x00000020 /*!< Clear FIFO Clear RX */
- #define BCM2835_SPI0_CS_CLEAR_TX 0x00000010 /*!< Clear FIFO Clear TX */
- #define BCM2835_SPI0_CS_CPOL 0x00000008 /*!< Clock Polarity */
- #define BCM2835_SPI0_CS_CPHA 0x00000004 /*!< Clock Phase */
- #define BCM2835_SPI0_CS_CS 0x00000003 /*!< Chip Select */
-
- /*! \brief bcm2835SPIBitOrder SPI Bit order
- Specifies the SPI data bit ordering for bcm2835_spi_setBitOrder()
- */
- typedef enum {
- BCM2835_SPI_BIT_ORDER_LSBFIRST = 0, /*!< LSB First */
- BCM2835_SPI_BIT_ORDER_MSBFIRST = 1 /*!< MSB First */
- } bcm2835SPIBitOrder;
-
- /*! \brief SPI Data mode
- Specify the SPI data mode to be passed to bcm2835_spi_setDataMode()
- */
- typedef enum {
- BCM2835_SPI_MODE0 = 0, /*!< CPOL = 0, CPHA = 0 */
- BCM2835_SPI_MODE1 = 1, /*!< CPOL = 0, CPHA = 1 */
- BCM2835_SPI_MODE2 = 2, /*!< CPOL = 1, CPHA = 0 */
- BCM2835_SPI_MODE3 = 3 /*!< CPOL = 1, CPHA = 1 */
- } bcm2835SPIMode;
-
- /*! \brief bcm2835SPIChipSelect
- Specify the SPI chip select pin(s)
- */
- typedef enum {
- BCM2835_SPI_CS0 = 0, /*!< Chip Select 0 */
- BCM2835_SPI_CS1 = 1, /*!< Chip Select 1 */
- BCM2835_SPI_CS2 = 2, /*!< Chip Select 2 (ie pins CS1 and CS2 are asserted) */
- BCM2835_SPI_CS_NONE = 3 /*!< No CS, control it yourself */
- } bcm2835SPIChipSelect;
-
- /*! \brief bcm2835SPIClockDivider
- Specifies the divider used to generate the SPI clock from the system clock.
- Figures below give the divider, clock period and clock frequency.
- Clock divided is based on nominal base clock rate of 250MHz
- It is reported that (contrary to the documentation) any even divider may used.
- The frequencies shown for each divider have been confirmed by measurement.
- */
- typedef enum {
- BCM2835_SPI_CLOCK_DIVIDER_65536 = 0, /*!< 65536 = 262.144us = 3.814697260kHz */
- BCM2835_SPI_CLOCK_DIVIDER_32768 = 32768, /*!< 32768 = 131.072us = 7.629394531kHz */
- BCM2835_SPI_CLOCK_DIVIDER_16384 = 16384, /*!< 16384 = 65.536us = 15.25878906kHz */
- BCM2835_SPI_CLOCK_DIVIDER_8192 = 8192, /*!< 8192 = 32.768us = 30/51757813kHz */
- BCM2835_SPI_CLOCK_DIVIDER_4096 = 4096, /*!< 4096 = 16.384us = 61.03515625kHz */
- BCM2835_SPI_CLOCK_DIVIDER_2048 = 2048, /*!< 2048 = 8.192us = 122.0703125kHz */
- BCM2835_SPI_CLOCK_DIVIDER_1024 = 1024, /*!< 1024 = 4.096us = 244.140625kHz */
- BCM2835_SPI_CLOCK_DIVIDER_512 = 512, /*!< 512 = 2.048us = 488.28125kHz */
- BCM2835_SPI_CLOCK_DIVIDER_256 = 256, /*!< 256 = 1.024us = 976.5625kHz */
- BCM2835_SPI_CLOCK_DIVIDER_128 = 128, /*!< 128 = 512ns = = 1.953125MHz */
- BCM2835_SPI_CLOCK_DIVIDER_64 = 64, /*!< 64 = 256ns = 3.90625MHz */
- BCM2835_SPI_CLOCK_DIVIDER_32 = 32, /*!< 32 = 128ns = 7.8125MHz */
- BCM2835_SPI_CLOCK_DIVIDER_16 = 16, /*!< 16 = 64ns = 15.625MHz */
- BCM2835_SPI_CLOCK_DIVIDER_8 = 8, /*!< 8 = 32ns = 31.25MHz */
- BCM2835_SPI_CLOCK_DIVIDER_4 = 4, /*!< 4 = 16ns = 62.5MHz */
- BCM2835_SPI_CLOCK_DIVIDER_2 = 2, /*!< 2 = 8ns = 125MHz, fastest you can get */
- BCM2835_SPI_CLOCK_DIVIDER_1 = 1 /*!< 1 = 262.144us = 3.814697260kHz, same as 0/65536 */
- } bcm2835SPIClockDivider;
-
- /* Defines for I2C
- GPIO register offsets from BCM2835_BSC*_BASE.
- Offsets into the BSC Peripheral block in bytes per 3.1 BSC Register Map
- */
- #define BCM2835_BSC_C 0x0000 /*!< BSC Master Control */
- #define BCM2835_BSC_S 0x0004 /*!< BSC Master Status */
- #define BCM2835_BSC_DLEN 0x0008 /*!< BSC Master Data Length */
- #define BCM2835_BSC_A 0x000c /*!< BSC Master Slave Address */
- #define BCM2835_BSC_FIFO 0x0010 /*!< BSC Master Data FIFO */
- #define BCM2835_BSC_DIV 0x0014 /*!< BSC Master Clock Divider */
- #define BCM2835_BSC_DEL 0x0018 /*!< BSC Master Data Delay */
- #define BCM2835_BSC_CLKT 0x001c /*!< BSC Master Clock Stretch Timeout */
-
- /* Register masks for BSC_C */
- #define BCM2835_BSC_C_I2CEN 0x00008000 /*!< I2C Enable, 0 = disabled, 1 = enabled */
- #define BCM2835_BSC_C_INTR 0x00000400 /*!< Interrupt on RX */
- #define BCM2835_BSC_C_INTT 0x00000200 /*!< Interrupt on TX */
- #define BCM2835_BSC_C_INTD 0x00000100 /*!< Interrupt on DONE */
- #define BCM2835_BSC_C_ST 0x00000080 /*!< Start transfer, 1 = Start a new transfer */
- #define BCM2835_BSC_C_CLEAR_1 0x00000020 /*!< Clear FIFO Clear */
- #define BCM2835_BSC_C_CLEAR_2 0x00000010 /*!< Clear FIFO Clear */
- #define BCM2835_BSC_C_READ 0x00000001 /*!< Read transfer */
-
- /* Register masks for BSC_S */
- #define BCM2835_BSC_S_CLKT 0x00000200 /*!< Clock stretch timeout */
- #define BCM2835_BSC_S_ERR 0x00000100 /*!< ACK error */
- #define BCM2835_BSC_S_RXF 0x00000080 /*!< RXF FIFO full, 0 = FIFO is not full, 1 = FIFO is full */
- #define BCM2835_BSC_S_TXE 0x00000040 /*!< TXE FIFO full, 0 = FIFO is not full, 1 = FIFO is full */
- #define BCM2835_BSC_S_RXD 0x00000020 /*!< RXD FIFO contains data */
- #define BCM2835_BSC_S_TXD 0x00000010 /*!< TXD FIFO can accept data */
- #define BCM2835_BSC_S_RXR 0x00000008 /*!< RXR FIFO needs reading (full) */
- #define BCM2835_BSC_S_TXW 0x00000004 /*!< TXW FIFO needs writing (full) */
- #define BCM2835_BSC_S_DONE 0x00000002 /*!< Transfer DONE */
- #define BCM2835_BSC_S_TA 0x00000001 /*!< Transfer Active */
-
- #define BCM2835_BSC_FIFO_SIZE 16 /*!< BSC FIFO size */
-
- /*! \brief bcm2835I2CClockDivider
- Specifies the divider used to generate the I2C clock from the system clock.
- Clock divided is based on nominal base clock rate of 250MHz
- */
- typedef enum {
- BCM2835_I2C_CLOCK_DIVIDER_2500 = 2500, /*!< 2500 = 10us = 100 kHz */
- BCM2835_I2C_CLOCK_DIVIDER_626 = 626, /*!< 622 = 2.504us = 399.3610 kHz */
- BCM2835_I2C_CLOCK_DIVIDER_150 = 150, /*!< 150 = 60ns = 1.666 MHz (default at reset) */
- BCM2835_I2C_CLOCK_DIVIDER_148 = 148 /*!< 148 = 59ns = 1.689 MHz */
- } bcm2835I2CClockDivider;
-
- /*! \brief bcm2835I2CReasonCodes
- Specifies the reason codes for the bcm2835_i2c_write and bcm2835_i2c_read functions.
- */
- typedef enum {
- BCM2835_I2C_REASON_OK = 0x00, /*!< Success */
- BCM2835_I2C_REASON_ERROR_NACK = 0x01, /*!< Received a NACK */
- BCM2835_I2C_REASON_ERROR_CLKT = 0x02, /*!< Received Clock Stretch Timeout */
- BCM2835_I2C_REASON_ERROR_DATA = 0x04 /*!< Not all data is sent / received */
- } bcm2835I2CReasonCodes;
-
- /* Defines for ST
- GPIO register offsets from BCM2835_ST_BASE.
- Offsets into the ST Peripheral block in bytes per 12.1 System Timer Registers
- The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter.
- BCM2835_ST_CLO is the System Timer Counter Lower bits register.
- The system timer free-running counter lower register is a read-only register that returns the current value
- of the lower 32-bits of the free running counter.
- BCM2835_ST_CHI is the System Timer Counter Upper bits register.
- The system timer free-running counter upper register is a read-only register that returns the current value
- of the upper 32-bits of the free running counter.
- */
- #define BCM2835_ST_CS 0x0000 /*!< System Timer Control/Status */
- #define BCM2835_ST_CLO 0x0004 /*!< System Timer Counter Lower 32 bits */
- #define BCM2835_ST_CHI 0x0008 /*!< System Timer Counter Upper 32 bits */
-
- /* Defines for PWM, word offsets (ie 4 byte multiples) */
- #define BCM2835_PWM_CONTROL 0 /*!< PWM Control register */
- #define BCM2835_PWM_STATUS 1 /*!< PWM Status register */
- #define BCM2835_PWM_DMAC 2 /*!< PWM DMA Configuration */
- #define BCM2835_PWM0_RANGE 4 /*!< PWM Channel 0 Range */
- #define BCM2835_PWM0_DATA 5 /*!< PWM Channel 0 Data */
- #define BCM2835_PWM_FIF1 6 /*!< PWM FIFO Input */
- #define BCM2835_PWM1_RANGE 8 /*!< PWM Channel 1 Range */
- #define BCM2835_PWM1_DATA 9 /*!< PWM Channel 1 Data */
-
- /* Defines for PWM Clock, word offsets (ie 4 byte multiples) */
- #define BCM2835_PWMCLK_CNTL 40 /*!< PWM Clock Control */
- #define BCM2835_PWMCLK_DIV 41 /*!< PWM Clock Divider */
- #define BCM2835_PWM_PASSWRD (0x5A << 24) /*!< Password to enable setting PWM clock */
-
- #define BCM2835_PWM1_MS_MODE 0x8000 /*!< Run in Mark/Space mode */
- #define BCM2835_PWM1_USEFIFO 0x2000 /*!< Data from FIFO */
- #define BCM2835_PWM1_REVPOLAR 0x1000 /*!< Reverse polarity */
- #define BCM2835_PWM1_OFFSTATE 0x0800 /*!< Ouput Off state */
- #define BCM2835_PWM1_REPEATFF 0x0400 /*!< Repeat last value if FIFO empty */
- #define BCM2835_PWM1_SERIAL 0x0200 /*!< Run in serial mode */
- #define BCM2835_PWM1_ENABLE 0x0100 /*!< Channel Enable */
-
- #define BCM2835_PWM0_MS_MODE 0x0080 /*!< Run in Mark/Space mode */
- #define BCM2835_PWM_CLEAR_FIFO 0x0040 /*!< Clear FIFO */
- #define BCM2835_PWM0_USEFIFO 0x0020 /*!< Data from FIFO */
- #define BCM2835_PWM0_REVPOLAR 0x0010 /*!< Reverse polarity */
- #define BCM2835_PWM0_OFFSTATE 0x0008 /*!< Ouput Off state */
- #define BCM2835_PWM0_REPEATFF 0x0004 /*!< Repeat last value if FIFO empty */
- #define BCM2835_PWM0_SERIAL 0x0002 /*!< Run in serial mode */
- #define BCM2835_PWM0_ENABLE 0x0001 /*!< Channel Enable */
-
- /*! \brief bcm2835PWMClockDivider
- Specifies the divider used to generate the PWM clock from the system clock.
- Figures below give the divider, clock period and clock frequency.
- Clock divided is based on nominal PWM base clock rate of 19.2MHz
- The frequencies shown for each divider have been confirmed by measurement
- */
- typedef enum {
- BCM2835_PWM_CLOCK_DIVIDER_2048 = 2048, /*!< 2048 = 9.375kHz */
- BCM2835_PWM_CLOCK_DIVIDER_1024 = 1024, /*!< 1024 = 18.75kHz */
- BCM2835_PWM_CLOCK_DIVIDER_512 = 512, /*!< 512 = 37.5kHz */
- BCM2835_PWM_CLOCK_DIVIDER_256 = 256, /*!< 256 = 75kHz */
- BCM2835_PWM_CLOCK_DIVIDER_128 = 128, /*!< 128 = 150kHz */
- BCM2835_PWM_CLOCK_DIVIDER_64 = 64, /*!< 64 = 300kHz */
- BCM2835_PWM_CLOCK_DIVIDER_32 = 32, /*!< 32 = 600.0kHz */
- BCM2835_PWM_CLOCK_DIVIDER_16 = 16, /*!< 16 = 1.2MHz */
- BCM2835_PWM_CLOCK_DIVIDER_8 = 8, /*!< 8 = 2.4MHz */
- BCM2835_PWM_CLOCK_DIVIDER_4 = 4, /*!< 4 = 4.8MHz */
- BCM2835_PWM_CLOCK_DIVIDER_2 = 2, /*!< 2 = 9.6MHz, fastest you can get */
- BCM2835_PWM_CLOCK_DIVIDER_1 = 1 /*!< 1 = 4.6875kHz, same as divider 4096 */
- } bcm2835PWMClockDivider;
-
- /*! @} */
-
- /* Historical name compatibility */
- #ifndef BCM2835_NO_DELAY_COMPATIBILITY
- #define delay(x) bcm2835_delay(x)
- #define delayMicroseconds(x) bcm2835_delayMicroseconds(x)
- #endif
-
- #ifdef __cplusplus
- extern "C" {
- #endif
-
- /*! \defgroup BCM2835initgrp Library initialisation and management
- \ingroup BCM2835grp
- These functions allow you to intialise and control the bcm2835 library
- @{
- */
-
- /*! Initialise the library by opening /dev/mem (if you are root)
- or /dev/gpiomem (if you are not)
- and getting pointers to the
- internal memory for BCM 2835 device registers. You must call this (successfully)
- before calling any other
- functions in this library (except bcm2835_set_debug).
- If bcm2835_init() fails by returning 0,
- calling any other function may result in crashes or other failures.
- If bcm2835_init() succeeds but you are not running as root, then only gpio operations
- are permitted, and calling any other functions may result in crashes or other failures. .
- Prints messages to stderr in case of errors.
- \return 1 if successful else 0
- */
- extern int bcm2835_init(void);
-
- /*! Close the library, deallocating any allocated memory and closing /dev/mem
- \return 1 if successful else 0
- */
- extern int bcm2835_close(void);
-
- /*! Sets the debug level of the library.
- A value of 1 prevents mapping to /dev/mem, and makes the library print out
- what it would do, rather than accessing the GPIO registers.
- A value of 0, the default, causes normal operation.
- Call this before calling bcm2835_init();
- \param[in] debug The new debug level. 1 means debug
- */
- extern void bcm2835_set_debug(uint8_t debug);
-
- /*! Returns the version number of the library, same as BCM2835_VERSION
- \return the current library version number
- */
- extern unsigned int bcm2835_version(void);
-
- /*! @} */
-
- /*! \defgroup BCM2835lowlevelgrp Low level register access
- \ingroup BCM2835grp
- These functions provide low level register access, and should not generally
- need to be used
-
- @{
- */
-
- /*! Gets the base of a register
- \param[in] regbase You can use one of the common values BCM2835_REGBASE_*
- in \ref bcm2835RegisterBase
- \return the register base
- \sa Physical Addresses
- */
- extern uint32_t* bcm2835_regbase(uint8_t regbase);
-
- /*! Reads 32 bit value from a peripheral address WITH a memory barrier before and after each read.
- This is safe, but slow. The MB before protects this read from any in-flight reads that didn't
- use a MB. The MB after protects subsequent reads from another peripheral.
-
- \param[in] paddr Physical address to read from. See BCM2835_GPIO_BASE etc.
- \return the value read from the 32 bit register
- \sa Physical Addresses
- */
- extern uint32_t bcm2835_peri_read(volatile uint32_t* paddr);
-
- /*! Reads 32 bit value from a peripheral address WITHOUT the read barriers
- You should only use this when:
- o your code has previously called bcm2835_peri_read() for a register
- within the same peripheral, and no read or write to another peripheral has occurred since.
- o your code has called bcm2835_memory_barrier() since the last access to ANOTHER peripheral.
-
- \param[in] paddr Physical address to read from. See BCM2835_GPIO_BASE etc.
- \return the value read from the 32 bit register
- \sa Physical Addresses
- */
- extern uint32_t bcm2835_peri_read_nb(volatile uint32_t* paddr);
-
-
- /*! Writes 32 bit value from a peripheral address WITH a memory barrier before and after each write
- This is safe, but slow. The MB before ensures that any in-flight write to another peripheral
- completes before this write is issued. The MB after ensures that subsequent reads and writes
- to another peripheral will see the effect of this write.
-
- This is a tricky optimization; if you aren't sure, use the barrier version.
-
- \param[in] paddr Physical address to read from. See BCM2835_GPIO_BASE etc.
- \param[in] value The 32 bit value to write
- \sa Physical Addresses
- */
- extern void bcm2835_peri_write(volatile uint32_t* paddr, uint32_t value);
-
- /*! Writes 32 bit value from a peripheral address without the write barrier
- You should only use this when:
- o your code has previously called bcm2835_peri_write() for a register
- within the same peripheral, and no other peripheral access has occurred since.
- o your code has called bcm2835_memory_barrier() since the last access to ANOTHER peripheral.
-
- This is a tricky optimization; if you aren't sure, use the barrier version.
-
- \param[in] paddr Physical address to read from. See BCM2835_GPIO_BASE etc.
- \param[in] value The 32 bit value to write
- \sa Physical Addresses
- */
- extern void bcm2835_peri_write_nb(volatile uint32_t* paddr, uint32_t value);
-
- /*! Alters a number of bits in a 32 peripheral regsiter.
- It reads the current valu and then alters the bits defines as 1 in mask,
- according to the bit value in value.
- All other bits that are 0 in the mask are unaffected.
- Use this to alter a subset of the bits in a register.
- Memory barriers are used. Note that this is not atomic; an interrupt
- routine can cause unexpected results.
- \param[in] paddr Physical address to read from. See BCM2835_GPIO_BASE etc.
- \param[in] value The 32 bit value to write, masked in by mask.
- \param[in] mask Bitmask that defines the bits that will be altered in the register.
- \sa Physical Addresses
- */
- extern void bcm2835_peri_set_bits(volatile uint32_t* paddr, uint32_t value, uint32_t mask);
- /*! @} end of lowlevel */
-
- /*! \defgroup BCM2835gpiogrp GPIO register access
- \ingroup BCM2835grp
- These functions allow you to control the GPIO interface. You can set the
- function of each GPIO pin, read the input state and set the output state.
- @{
- */
-
- /*! Sets the Function Select register for the given pin, which configures
- the pin as Input, Output or one of the 6 alternate functions.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \param[in] mode Mode to set the pin to, one of BCM2835_GPIO_FSEL_* from \ref bcm2835FunctionSelect
- */
- extern void bcm2835_gpio_fsel(uint8_t pin, uint8_t mode);
-
- /*! Sets the specified pin output to
- HIGH.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \sa bcm2835_gpio_write()
- */
- extern void bcm2835_gpio_set(uint8_t pin);
-
- /*! Sets the specified pin output to
- LOW.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \sa bcm2835_gpio_write()
- */
- extern void bcm2835_gpio_clr(uint8_t pin);
-
- /*! Sets any of the first 32 GPIO output pins specified in the mask to
- HIGH.
- \param[in] mask Mask of pins to affect. Use eg: (1 << RPI_GPIO_P1_03) | (1 << RPI_GPIO_P1_05)
- \sa bcm2835_gpio_write_multi()
- */
- extern void bcm2835_gpio_set_multi(uint32_t mask);
-
- /*! Sets any of the first 32 GPIO output pins specified in the mask to
- LOW.
- \param[in] mask Mask of pins to affect. Use eg: (1 << RPI_GPIO_P1_03) | (1 << RPI_GPIO_P1_05)
- \sa bcm2835_gpio_write_multi()
- */
- extern void bcm2835_gpio_clr_multi(uint32_t mask);
-
- /*! Reads the current level on the specified
- pin and returns either HIGH or LOW. Works whether or not the pin
- is an input or an output.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \return the current level either HIGH or LOW
- */
- extern uint8_t bcm2835_gpio_lev(uint8_t pin);
-
- /*! Event Detect Status.
- Tests whether the specified pin has detected a level or edge
- as requested by bcm2835_gpio_ren(), bcm2835_gpio_fen(), bcm2835_gpio_hen(),
- bcm2835_gpio_len(), bcm2835_gpio_aren(), bcm2835_gpio_afen().
- Clear the flag for a given pin by calling bcm2835_gpio_set_eds(pin);
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \return HIGH if the event detect status for the given pin is true.
- */
- extern uint8_t bcm2835_gpio_eds(uint8_t pin);
-
- /*! Same as bcm2835_gpio_eds() but checks if any of the pins specified in
- the mask have detected a level or edge.
- \param[in] mask Mask of pins to check. Use eg: (1 << RPI_GPIO_P1_03) | (1 << RPI_GPIO_P1_05)
- \return Mask of pins HIGH if the event detect status for the given pin is true.
- */
- extern uint32_t bcm2835_gpio_eds_multi(uint32_t mask);
-
- /*! Sets the Event Detect Status register for a given pin to 1,
- which has the effect of clearing the flag. Use this afer seeing
- an Event Detect Status on the pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_set_eds(uint8_t pin);
-
- /*! Same as bcm2835_gpio_set_eds() but clears the flag for any pin which
- is set in the mask.
- \param[in] mask Mask of pins to clear. Use eg: (1 << RPI_GPIO_P1_03) | (1 << RPI_GPIO_P1_05)
- */
- extern void bcm2835_gpio_set_eds_multi(uint32_t mask);
-
- /*! Enable Rising Edge Detect Enable for the specified pin.
- When a rising edge is detected, sets the appropriate pin in Event Detect Status.
- The GPRENn registers use
- synchronous edge detection. This means the input signal is sampled using the
- system clock and then it is looking for a ?011? pattern on the sampled signal. This
- has the effect of suppressing glitches.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_ren(uint8_t pin);
-
- /*! Disable Rising Edge Detect Enable for the specified pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_clr_ren(uint8_t pin);
-
- /*! Enable Falling Edge Detect Enable for the specified pin.
- When a falling edge is detected, sets the appropriate pin in Event Detect Status.
- The GPRENn registers use
- synchronous edge detection. This means the input signal is sampled using the
- system clock and then it is looking for a ?100? pattern on the sampled signal. This
- has the effect of suppressing glitches.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_fen(uint8_t pin);
-
- /*! Disable Falling Edge Detect Enable for the specified pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_clr_fen(uint8_t pin);
-
- /*! Enable High Detect Enable for the specified pin.
- When a HIGH level is detected on the pin, sets the appropriate pin in Event Detect Status.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_hen(uint8_t pin);
-
- /*! Disable High Detect Enable for the specified pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_clr_hen(uint8_t pin);
-
- /*! Enable Low Detect Enable for the specified pin.
- When a LOW level is detected on the pin, sets the appropriate pin in Event Detect Status.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_len(uint8_t pin);
-
- /*! Disable Low Detect Enable for the specified pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_clr_len(uint8_t pin);
-
- /*! Enable Asynchronous Rising Edge Detect Enable for the specified pin.
- When a rising edge is detected, sets the appropriate pin in Event Detect Status.
- Asynchronous means the incoming signal is not sampled by the system clock. As such
- rising edges of very short duration can be detected.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_aren(uint8_t pin);
-
- /*! Disable Asynchronous Rising Edge Detect Enable for the specified pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_clr_aren(uint8_t pin);
-
- /*! Enable Asynchronous Falling Edge Detect Enable for the specified pin.
- When a falling edge is detected, sets the appropriate pin in Event Detect Status.
- Asynchronous means the incoming signal is not sampled by the system clock. As such
- falling edges of very short duration can be detected.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_afen(uint8_t pin);
-
- /*! Disable Asynchronous Falling Edge Detect Enable for the specified pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- */
- extern void bcm2835_gpio_clr_afen(uint8_t pin);
-
- /*! Sets the Pull-up/down register for the given pin. This is
- used with bcm2835_gpio_pudclk() to set the Pull-up/down resistor for the given pin.
- However, it is usually more convenient to use bcm2835_gpio_set_pud().
- \param[in] pud The desired Pull-up/down mode. One of BCM2835_GPIO_PUD_* from bcm2835PUDControl
- \sa bcm2835_gpio_set_pud()
- */
- extern void bcm2835_gpio_pud(uint8_t pud);
-
- /*! Clocks the Pull-up/down value set earlier by bcm2835_gpio_pud() into the pin.
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \param[in] on HIGH to clock the value from bcm2835_gpio_pud() into the pin.
- LOW to remove the clock.
- \sa bcm2835_gpio_set_pud()
- */
- extern void bcm2835_gpio_pudclk(uint8_t pin, uint8_t on);
-
- /*! Reads and returns the Pad Control for the given GPIO group.
- \param[in] group The GPIO pad group number, one of BCM2835_PAD_GROUP_GPIO_*
- \return Mask of bits from BCM2835_PAD_* from \ref bcm2835PadGroup
- */
- extern uint32_t bcm2835_gpio_pad(uint8_t group);
-
- /*! Sets the Pad Control for the given GPIO group.
- \param[in] group The GPIO pad group number, one of BCM2835_PAD_GROUP_GPIO_*
- \param[in] control Mask of bits from BCM2835_PAD_* from \ref bcm2835PadGroup. Note
- that it is not necessary to include BCM2835_PAD_PASSWRD in the mask as this
- is automatically included.
- */
- extern void bcm2835_gpio_set_pad(uint8_t group, uint32_t control);
-
- /*! Delays for the specified number of milliseconds.
- Uses nanosleep(), and therefore does not use CPU until the time is up.
- However, you are at the mercy of nanosleep(). From the manual for nanosleep():
- If the interval specified in req is not an exact multiple of the granularity
- underlying clock (see time(7)), then the interval will be
- rounded up to the next multiple. Furthermore, after the sleep completes,
- there may still be a delay before the CPU becomes free to once
- again execute the calling thread.
- \param[in] millis Delay in milliseconds
- */
- extern void bcm2835_delay (unsigned int millis);
-
- /*! Delays for the specified number of microseconds.
- Uses a combination of nanosleep() and a busy wait loop on the BCM2835 system timers,
- However, you are at the mercy of nanosleep(). From the manual for nanosleep():
- If the interval specified in req is not an exact multiple of the granularity
- underlying clock (see time(7)), then the interval will be
- rounded up to the next multiple. Furthermore, after the sleep completes,
- there may still be a delay before the CPU becomes free to once
- again execute the calling thread.
- For times less than about 450 microseconds, uses a busy wait on the System Timer.
- It is reported that a delay of 0 microseconds on RaspberryPi will in fact
- result in a delay of about 80 microseconds. Your mileage may vary.
- \param[in] micros Delay in microseconds
- */
- extern void bcm2835_delayMicroseconds (uint64_t micros);
-
- /*! Sets the output state of the specified pin
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \param[in] on HIGH sets the output to HIGH and LOW to LOW.
- */
- extern void bcm2835_gpio_write(uint8_t pin, uint8_t on);
-
- /*! Sets any of the first 32 GPIO output pins specified in the mask to the state given by on
- \param[in] mask Mask of pins to affect. Use eg: (1 << RPI_GPIO_P1_03) | (1 << RPI_GPIO_P1_05)
- \param[in] on HIGH sets the output to HIGH and LOW to LOW.
- */
- extern void bcm2835_gpio_write_multi(uint32_t mask, uint8_t on);
-
- /*! Sets the first 32 GPIO output pins specified in the mask to the value given by value
- \param[in] value values required for each bit masked in by mask, eg: (1 << RPI_GPIO_P1_03) | (1 << RPI_GPIO_P1_05)
- \param[in] mask Mask of pins to affect. Use eg: (1 << RPI_GPIO_P1_03) | (1 << RPI_GPIO_P1_05)
- */
- extern void bcm2835_gpio_write_mask(uint32_t value, uint32_t mask);
-
- /*! Sets the Pull-up/down mode for the specified pin. This is more convenient than
- clocking the mode in with bcm2835_gpio_pud() and bcm2835_gpio_pudclk().
- \param[in] pin GPIO number, or one of RPI_GPIO_P1_* from \ref RPiGPIOPin.
- \param[in] pud The desired Pull-up/down mode. One of BCM2835_GPIO_PUD_* from bcm2835PUDControl
- */
- extern void bcm2835_gpio_set_pud(uint8_t pin, uint8_t pud);
-
- /*! @} */
-
- /*! \defgroup BCM2835spigrp SPI access
- \ingroup BCM2835grp
- These functions let you use SPI0 (Serial Peripheral Interface) to
- interface with an external SPI device.
- @{
- */
-
- /*! Start SPI operations.
- Forces RPi SPI0 pins P1-19 (MOSI), P1-21 (MISO), P1-23 (CLK), P1-24 (CE0) and P1-26 (CE1)
- to alternate function ALT0, which enables those pins for SPI interface.
- You should call bcm2835_spi_end() when all SPI funcitons are complete to return the pins to
- their default functions.
- \sa bcm2835_spi_end()
- \return 1 if successful, 0 otherwise (perhaps because you are not running as root)
- */
- extern int bcm2835_spi_begin(void);
-
- /*! End SPI operations.
- SPI0 pins P1-19 (MOSI), P1-21 (MISO), P1-23 (CLK), P1-24 (CE0) and P1-26 (CE1)
- are returned to their default INPUT behaviour.
- */
- extern void bcm2835_spi_end(void);
-
- /*! Sets the SPI bit order
- NOTE: has no effect. Not supported by SPI0.
- Defaults to
- \param[in] order The desired bit order, one of BCM2835_SPI_BIT_ORDER_*,
- see \ref bcm2835SPIBitOrder
- */
- extern void bcm2835_spi_setBitOrder(uint8_t order);
-
- /*! Sets the SPI clock divider and therefore the
- SPI clock speed.
- \param[in] divider The desired SPI clock divider, one of BCM2835_SPI_CLOCK_DIVIDER_*,
- see \ref bcm2835SPIClockDivider
- */
- extern void bcm2835_spi_setClockDivider(uint16_t divider);
-
- /*! Sets the SPI data mode
- Sets the clock polariy and phase
- \param[in] mode The desired data mode, one of BCM2835_SPI_MODE*,
- see \ref bcm2835SPIMode
- */
- extern void bcm2835_spi_setDataMode(uint8_t mode);
-
- /*! Sets the chip select pin(s)
- When an bcm2835_spi_transfer() is made, the selected pin(s) will be asserted during the
- transfer.
- \param[in] cs Specifies the CS pins(s) that are used to activate the desired slave.
- One of BCM2835_SPI_CS*, see \ref bcm2835SPIChipSelect
- */
- extern void bcm2835_spi_chipSelect(uint8_t cs);
-
- /*! Sets the chip select pin polarity for a given pin
- When an bcm2835_spi_transfer() occurs, the currently selected chip select pin(s)
- will be asserted to the
- value given by active. When transfers are not happening, the chip select pin(s)
- return to the complement (inactive) value.
- \param[in] cs The chip select pin to affect
- \param[in] active Whether the chip select pin is to be active HIGH
- */
- extern void bcm2835_spi_setChipSelectPolarity(uint8_t cs, uint8_t active);
-
- /*! Transfers one byte to and from the currently selected SPI slave.
- Asserts the currently selected CS pins (as previously set by bcm2835_spi_chipSelect)
- during the transfer.
- Clocks the 8 bit value out on MOSI, and simultaneously clocks in data from MISO.
- Returns the read data byte from the slave.
- Uses polled transfer as per section 10.6.1 of the BCM 2835 ARM Peripherls manual
- \param[in] value The 8 bit data byte to write to MOSI
- \return The 8 bit byte simultaneously read from MISO
- \sa bcm2835_spi_transfern()
- */
- extern uint8_t bcm2835_spi_transfer(uint8_t value);
-
- /*! Transfers any number of bytes to and from the currently selected SPI slave.
- Asserts the currently selected CS pins (as previously set by bcm2835_spi_chipSelect)
- during the transfer.
- Clocks the len 8 bit bytes out on MOSI, and simultaneously clocks in data from MISO.
- The data read read from the slave is placed into rbuf. rbuf must be at least len bytes long
- Uses polled transfer as per section 10.6.1 of the BCM 2835 ARM Peripherls manual
- \param[in] tbuf Buffer of bytes to send.
- \param[out] rbuf Received bytes will by put in this buffer
- \param[in] len Number of bytes in the tbuf buffer, and the number of bytes to send/received
- \sa bcm2835_spi_transfer()
- */
- extern void bcm2835_spi_transfernb(char* tbuf, char* rbuf, uint32_t len);
-
- /*! Transfers any number of bytes to and from the currently selected SPI slave
- using bcm2835_spi_transfernb.
- The returned data from the slave replaces the transmitted data in the buffer.
- \param[in,out] buf Buffer of bytes to send. Received bytes will replace the contents
- \param[in] len Number of bytes int eh buffer, and the number of bytes to send/received
- \sa bcm2835_spi_transfer()
- */
- extern void bcm2835_spi_transfern(char* buf, uint32_t len);
-
- /*! Transfers any number of bytes to the currently selected SPI slave.
- Asserts the currently selected CS pins (as previously set by bcm2835_spi_chipSelect)
- during the transfer.
- \param[in] buf Buffer of bytes to send.
- \param[in] len Number of bytes in the tbuf buffer, and the number of bytes to send
- */
- extern void bcm2835_spi_writenb(char* buf, uint32_t len);
-
- /*! @} */
-
- /*! \defgroup BCM2835i2cgrp I2C access
- \ingroup BCM2835grp
- These functions let you use I2C (The Broadcom Serial Control bus with the Philips
- I2C bus/interface version 2.1 January 2000.) to interface with an external I2C device.
- @{
- */
-
- /*! Start I2C operations.
- Forces RPi I2C pins P1-03 (SDA) and P1-05 (SCL)
- to alternate function ALT0, which enables those pins for I2C interface.
- You should call bcm2835_i2c_end() when all I2C functions are complete to return the pins to
- their default functions
- \return 1 if successful, 0 otherwise (perhaps because you are not running as root)
- \sa bcm2835_i2c_end()
- */
- extern int bcm2835_i2c_begin(void);
-
- /*! End I2C operations.
- I2C pins P1-03 (SDA) and P1-05 (SCL)
- are returned to their default INPUT behaviour.
- */
- extern void bcm2835_i2c_end(void);
-
- /*! Sets the I2C slave address.
- \param[in] addr The I2C slave address.
- */
- extern void bcm2835_i2c_setSlaveAddress(uint8_t addr);
-
- /*! Sets the I2C clock divider and therefore the I2C clock speed.
- \param[in] divider The desired I2C clock divider, one of BCM2835_I2C_CLOCK_DIVIDER_*,
- see \ref bcm2835I2CClockDivider
- */
- extern void bcm2835_i2c_setClockDivider(uint16_t divider);
-
- /*! Sets the I2C clock divider by converting the baudrate parameter to
- the equivalent I2C clock divider. ( see \sa bcm2835_i2c_setClockDivider)
- For the I2C standard 100khz you would set baudrate to 100000
- The use of baudrate corresponds to its use in the I2C kernel device
- driver. (Of course, bcm2835 has nothing to do with the kernel driver)
- */
- extern void bcm2835_i2c_set_baudrate(uint32_t baudrate);
-
- /*! Transfers any number of bytes to the currently selected I2C slave.
- (as previously set by \sa bcm2835_i2c_setSlaveAddress)
- \param[in] buf Buffer of bytes to send.
- \param[in] len Number of bytes in the buf buffer, and the number of bytes to send.
- \return reason see \ref bcm2835I2CReasonCodes
- */
- extern uint8_t bcm2835_i2c_write(const char * buf, uint32_t len);
-
- /*! Transfers any number of bytes from the currently selected I2C slave.
- (as previously set by \sa bcm2835_i2c_setSlaveAddress)
- \param[in] buf Buffer of bytes to receive.
- \param[in] len Number of bytes in the buf buffer, and the number of bytes to received.
- \return reason see \ref bcm2835I2CReasonCodes
- */
- extern uint8_t bcm2835_i2c_read(char* buf, uint32_t len);
-
- /*! Allows reading from I2C slaves that require a repeated start (without any prior stop)
- to read after the required slave register has been set. For example, the popular
- MPL3115A2 pressure and temperature sensor. Note that your device must support or
- require this mode. If your device does not require this mode then the standard
- combined:
- \sa bcm2835_i2c_write
- \sa bcm2835_i2c_read
- are a better choice.
- Will read from the slave previously set by \sa bcm2835_i2c_setSlaveAddress
- \param[in] regaddr Buffer containing the slave register you wish to read from.
- \param[in] buf Buffer of bytes to receive.
- \param[in] len Number of bytes in the buf buffer, and the number of bytes to received.
- \return reason see \ref bcm2835I2CReasonCodes
- */
- extern uint8_t bcm2835_i2c_read_register_rs(char* regaddr, char* buf, uint32_t len);
-
- /*! Allows sending an arbitrary number of bytes to I2C slaves before issuing a repeated
- start (with no prior stop) and reading a response.
- Necessary for devices that require such behavior, such as the MLX90620.
- Will write to and read from the slave previously set by \sa bcm2835_i2c_setSlaveAddress
- \param[in] cmds Buffer containing the bytes to send before the repeated start condition.
- \param[in] cmds_len Number of bytes to send from cmds buffer
- \param[in] buf Buffer of bytes to receive.
- \param[in] buf_len Number of bytes to receive in the buf buffer.
- \return reason see \ref bcm2835I2CReasonCodes
- */
- extern uint8_t bcm2835_i2c_write_read_rs(char* cmds, uint32_t cmds_len, char* buf,
- uint32_t buf_len);
-
- /*! @} */
-
- /*! \defgroup BCM2835stgrp System Timer access
- \ingroup BCM2835grp
- Allows access to and delays using the System Timer Counter.
- @{
- */
-
- /*! Read the System Timer Counter register.
- \return the value read from the System Timer Counter Lower 32 bits register
- */
- extern uint64_t bcm2835_st_read(void);
-
- /*! Delays for the specified number of microseconds with offset.
- \param[in] offset_micros Offset in microseconds
- \param[in] micros Delay in microseconds
- */
- extern void bcm2835_st_delay(uint64_t offset_micros, uint64_t micros);
-
- /*! @} */
-
- /*! \defgroup BCM2835pwmgrp Pulse Width Modulation
- \ingroup BCM2835grp
- Allows control of 2 independent PWM channels. A limited subset of GPIO pins
- can be connected to one of these 2 channels, allowing PWM control of GPIO pins.
- You have to set the desired pin into a particular Alt Fun to PWM output. See the PWM
- documentation on the Main Page.
- @{
- */
-
- /*! Sets the PWM clock divisor,
- to control the basic PWM pulse widths.
- \param[in] divisor Divides the basic 19.2MHz PWM clock. You can use one of the common
- values BCM2835_PWM_CLOCK_DIVIDER_* in \ref bcm2835PWMClockDivider
- */
- extern void bcm2835_pwm_set_clock(uint32_t divisor);
-
- /*! Sets the mode of the given PWM channel,
- allowing you to control the PWM mode and enable/disable that channel
- \param[in] channel The PWM channel. 0 or 1.
- \param[in] markspace Set true if you want Mark-Space mode. 0 for Balanced mode.
- \param[in] enabled Set true to enable this channel and produce PWM pulses.
- */
- extern void bcm2835_pwm_set_mode(uint8_t channel, uint8_t markspace, uint8_t enabled);
-
- /*! Sets the maximum range of the PWM output.
- The data value can vary between 0 and this range to control PWM output
- \param[in] channel The PWM channel. 0 or 1.
- \param[in] range The maximum value permitted for DATA.
- */
- extern void bcm2835_pwm_set_range(uint8_t channel, uint32_t range);
-
- /*! Sets the PWM pulse ratio to emit to DATA/RANGE,
- where RANGE is set by bcm2835_pwm_set_range().
- \param[in] channel The PWM channel. 0 or 1.
- \param[in] data Controls the PWM output ratio as a fraction of the range.
- Can vary from 0 to RANGE.
- */
- extern void bcm2835_pwm_set_data(uint8_t channel, uint32_t data);
-
- /*! @} */
- #ifdef __cplusplus
- }
- #endif
-
- #endif /* BCM2835_H */
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