source: rtems/bsps/arm/raspberrypi/include/bsp/spi.h @ 2afb22b

5
Last change on this file since 2afb22b was 2afb22b, checked in by Chris Johns <chrisj@…>, on 12/23/17 at 07:18:56

Remove make preinstall

A speciality of the RTEMS build system was the make preinstall step. It
copied header files from arbitrary locations into the build tree. The
header files were included via the -Bsome/build/tree/path GCC command
line option.

This has at least seven problems:

  • The make preinstall step itself needs time and disk space.
  • Errors in header files show up in the build tree copy. This makes it hard for editors to open the right file to fix the error.
  • There is no clear relationship between source and build tree header files. This makes an audit of the build process difficult.
  • The visibility of all header files in the build tree makes it difficult to enforce API barriers. For example it is discouraged to use BSP-specifics in the cpukit.
  • An introduction of a new build system is difficult.
  • Include paths specified by the -B option are system headers. This may suppress warnings.
  • The parallel build had sporadic failures on some hosts.

This patch removes the make preinstall step. All installed header
files are moved to dedicated include directories in the source tree.
Let @RTEMS_CPU@ be the target architecture, e.g. arm, powerpc, sparc,
etc. Let @RTEMS_BSP_FAMILIY@ be a BSP family base directory, e.g.
erc32, imx, qoriq, etc.

The new cpukit include directories are:

  • cpukit/include
  • cpukit/score/cpu/@RTEMS_CPU@/include
  • cpukit/libnetworking

The new BSP include directories are:

  • bsps/include
  • bsps/@RTEMS_CPU@/include
  • bsps/@RTEMS_CPU@/@RTEMS_BSP_FAMILIY@/include

There are build tree include directories for generated files.

The include directory order favours the most general header file, e.g.
it is not possible to override general header files via the include path
order.

The "bootstrap -p" option was removed. The new "bootstrap -H" option
should be used to regenerate the "headers.am" files.

Update #3254.
  • Property mode set to 100644
File size: 2.0 KB
Line 
1/**
2 * @file spi.h
3 *
4 * @ingroup raspberrypi_spi
5 *
6 * @brief Raspberry Pi specific SPI definitions.
7 */
8
9/*
10 *  Copyright (c) 2014-2015 Andre Marques <andre.lousa.marques at gmail.com>
11 *
12 *  The license and distribution terms for this file may be
13 *  found in the file LICENSE in this distribution or at
14 *  http://www.rtems.org/license/LICENSE.
15 */
16
17#ifndef LIBBSP_ARM_RASPBERRYPI_SPI_H
18#define LIBBSP_ARM_RASPBERRYPI_SPI_H
19
20#include <rtems/libi2c.h>
21
22#ifdef __cplusplus
23extern "C" {
24#endif /* __cplusplus */
25
26/**
27 * @name SPI constants.
28 *
29 * @{
30 */
31
32/**
33 * @brief GPU processor core clock rate in Hz.
34 *
35 * Unless configured otherwise on a "config.txt" file present on the SD card
36 * the GPU defaults to 250 MHz. Currently only 250 MHz is supported.
37 */
38
39/* TODO: It would be nice if this value could be probed at startup, probably
40 *       using the Mailbox interface since the usual way of setting this on
41 *       the hardware is through a "config.txt" text file on the SD card.
42 *       Having this setup on the configure.ac script would require changing
43 *       the same setting on two different places. */
44#define GPU_CORE_CLOCK_RATE 250000000
45
46/** @} */
47
48/**
49 * @name SPI directives.
50 *
51 * @{
52 */
53
54/**
55 * @brief Setups the Raspberry Pi SPI bus (located on the GPIO header)
56 *        on the "/dev/spi" device file, and registers the bus on the
57 *        libi2c API.
58 *
59 * @param[in] bidirectional_mode If TRUE sets the SPI bus to use 2-wire SPI,
60 *                               where the MOSI data line doubles as the
61 *                               slave out (SO) and slave in (SI) data lines.
62 *                               If FALSE the bus defaults to the usual
63 *                               3-wire SPI, with 2 separate data lines
64 *                               (MOSI and MISO).
65 *
66 * @retval Returns libi2c bus number.
67 * @retval <0 Could not register the bus. See @see rtems_libi2c_register_bus().
68 */
69extern int rpi_spi_init(bool bidirectional_mode);
70
71/** @} */
72
73#ifdef __cplusplus
74}
75#endif /* __cplusplus */
76
77#endif /* LIBBSP_ARM_RASPBERRYPI_SPI_H */
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