458 lines
11 KiB
C
458 lines
11 KiB
C
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//=============================================================================
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//
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//
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// Gertboard Demo
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//
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// main file
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//
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// This file is part of gertboard_demo.
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//
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//
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// Copyright (C) Gert Jan van Loo 2012
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// No rights reserved
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// You may treat this program as if it was in the public domain
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// POSSIBILITY OF SUCH DAMAGE.
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//
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//
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//
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// Try to strike a balance between keep code simple for
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// novice programmers but still have reasonable quality code
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//
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// DEMO GPIO mapping:
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// Function Mode
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// GPIO0= LED Output
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// GPIO1= LED Output
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// GPIO4= PWM channel-B Output
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// GPIO7= SPI chip select B Funct. 0
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// GPIO8= SPI chip select A Funct. 0
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// GPIO9= SPI MISO Funct. 0
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// GPIO10= SPI MOSI Funct. 0
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// GPIO11= SPI CLK Funct. 0
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// GPIO14= UART TXD (Funct. 0)
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// GPIO15= UART RXD (Funct. 0)
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// GPIO17= LED Output
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// GPIO18= PWM channel-A Funct. 5
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// GPIO21= LED Output
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// GPIO22= LED Output
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// GPIO23= LED Output
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// GPIO24= Pushbutton Input
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// GPIO25= Pushbutton Input
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//
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//
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// Notes:
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// 1/ In some Linux systems (e.g. Debian) the UART is used by Linux.
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// So for now do not demo the UART.
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// 2/ At the moment (16-March-2012) there is no Linux driver for
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// the audio yet so the PWM is free.
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// This is likely to change and in that case the Linux
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// audio/PWM driver must be disabled.
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//
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//
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#include "gertboard_demo.h"
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#define BCM2708_PERI_BASE 0x20000000
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#define CLOCK_BASE (BCM2708_PERI_BASE + 0x101000) /* Clocks */
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#define GPIO_BASE (BCM2708_PERI_BASE + 0x200000) /* GPIO */
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#define PWM_BASE (BCM2708_PERI_BASE + 0x20C000) /* PWM */
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#define SPI0_BASE (BCM2708_PERI_BASE + 0x204000) /* SPI0 controller */
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#define UART0_BASE (BCM2708_PERI_BASE + 0x201000) /* Uart 0 */
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#define UART1_BASE (BCM2708_PERI_BASE + 0x215000) /* Uart 1 (not used) */
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <dirent.h>
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#include <fcntl.h>
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#include <assert.h>
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#include <sys/mman.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#define PAGE_SIZE (4*1024)
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#define BLOCK_SIZE (4*1024)
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int mem_fd;
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char *clk_mem, *clk_map;
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char *gpio_mem, *gpio_map;
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char *pwm_mem, *pwm_map;
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char *spi0_mem, *spi0_map;
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char *uart_mem, *uart_map;
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// I/O access
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volatile unsigned *gpio;
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volatile unsigned *pwm;
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volatile unsigned *clk;
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volatile unsigned *spi0;
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volatile unsigned *uart;
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//
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// GPIO
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//
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// GPIO setup macros. Always use INP_GPIO(x) before using OUT_GPIO(x) or SET_GPIO_ALT(x,y)
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#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
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#define OUT_GPIO(g) *(gpio+((g)/10)) |= (1<<(((g)%10)*3))
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#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
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#define GPIO_SET0 *(gpio+7) // Set GPIO high bits 0-31
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#define GPIO_SET1 *(gpio+8) // Set GPIO high bits 32-53
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#define GPIO_CLR0 *(gpio+10) // Set GPIO low bits 0-31
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#define GPIO_CLR1 *(gpio+11) // Set GPIO low bits 32-53
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#define GPIO_PULL *(gpio+37) // Pull up/pull down
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#define GPIO_PULLCLK0 *(gpio+38) // Pull up/pull down clock
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//
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// UART 0
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//
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#define UART0_BAUD_HI *(uart+9)
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#define UART0_BAUD_LO *(uart+10)
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void setup_io();
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void restore_io();
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//
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// This is a software loop to wait
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// a short while.
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//
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void short_wait()
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{ int w;
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for (w=0; w<100; w++)
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{ w++;
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w--;
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}
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} // short_wait
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//
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// Simple SW wait loop
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//
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void long_wait(int v)
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{ int w;
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while (v--)
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for (w=-800000; w<800000; w++)
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{ w++;
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w--;
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}
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} // long_wait
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//
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// Set GPIO pins to the right mode
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// DEMO GPIO mapping:
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// Function Mode
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// GPIO0= LED Output
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// GPIO1= LED Output
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// GPIO4= PWM channel-B Output
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// GPIO7= SPI chip select B Funct. 0
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// GPIO8= SPI chip select A Funct. 0
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// GPIO9= SPI MISO Funct. 0
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// GPIO10= SPI MOSI Funct. 0
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// GPIO11= SPI CLK Funct. 0
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// GPIO14= UART TXD (Funct. 0)
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// GPIO15= UART RXD (Funct. 0)
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// GPIO17= LED Output
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// GPIO18= PWM channel-A Funct. 5
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// GPIO21= LED Output
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// GPIO22= LED Output
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// GPIO23= LED Output
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// GPIO24= Pushbutton Input
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// GPIO25= Pushbutton Input
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//
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// Always call INP_GPIO(x) first
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// as that is how the macros work
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void setup_gpio()
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{
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INP_GPIO(0); OUT_GPIO(0);
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INP_GPIO(1); OUT_GPIO(1);
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INP_GPIO(4); OUT_GPIO(4);
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INP_GPIO(7); SET_GPIO_ALT(7,0);
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INP_GPIO(8); SET_GPIO_ALT(8,0);
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INP_GPIO(9); SET_GPIO_ALT(9,0);
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INP_GPIO(10); SET_GPIO_ALT(10,0);
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INP_GPIO(11); SET_GPIO_ALT(11,0);
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// 14 and 15 are already set to UART mode
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// by Linux. Best if we don't touch them
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// INP_GPIO(14); SET_GPIO_ALT(14,0);
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// INP_GPIO(54); SET_GPIO_ALT(15,0);
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INP_GPIO(17); OUT_GPIO(17);
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INP_GPIO(18); SET_GPIO_ALT(18,5);
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INP_GPIO(21); OUT_GPIO(21);
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INP_GPIO(22); OUT_GPIO(22);
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INP_GPIO(23); OUT_GPIO(23);
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INP_GPIO(24);
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INP_GPIO(25);
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// enable pull-up on GPIO24&25
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GPIO_PULL = 2;
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short_wait();
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// clock on GPIO 24 & 25 (bit 24 & 25 set)
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GPIO_PULLCLK0 = 0x03000000;
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short_wait();
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GPIO_PULL = 0;
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GPIO_PULLCLK0 = 0;
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} // setup_gpio
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int main(void)
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{ char key;
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// Map the I/O sections
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setup_io();
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// Set ALL GPIO pins to the required mode
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setup_gpio();
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// Set up PWM module
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setup_pwm();
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// Setup the SPI
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setup_spi();
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// We don't touch the UART for now
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//
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// Here your main program can start
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//
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do {
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printf(" l/L : Walk the LEDS\n");
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printf(" b/B : Show buttons\n");
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printf(" m/M : Control the motor\n");
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printf(" a/A : Read the ADC values\n");
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printf(" c/C : ADC => Motor\n");
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printf("( D : Set the DAC values\n");
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printf(" q/Q : Quit program\n");
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key = getchar();
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switch (key)
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{
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case 'l':
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case 'L':
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quick_led_demo();
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break;
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case 'b':
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case 'B':
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quick_buttons_demo();
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break;
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case 'm':
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case 'M':
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quick_pwm_demo();
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break;
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case 'a':
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case 'A':
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quick_adc_demo();
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break;
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case 'c':
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case 'C':
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adc_pwm_demo();
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break;
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case 0x0A:
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case 0x0D:
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// ignore CR/LF
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break;
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default:
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printf("???\n");
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}
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} while (key!='q' && key!='Q');
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// make sure everything is off!
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leds_off();
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pwm_off();
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restore_io();
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return 0;
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} // main
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//
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// Set up memory regions to access the peripherals.
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// This is a bit of 'magic' which you should not touch.
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// It it also the part of the code which makes that
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// you have to use 'sudo' to run this program.
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//
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void setup_io()
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{
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/* open /dev/mem */
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if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
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printf("Can't open /dev/mem\n");
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printf("Did you forgot to use 'sudo .. ?'\n");
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exit (-1);
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}
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/*
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* mmap clock
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*/
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if ((clk_mem = malloc(BLOCK_SIZE + (PAGE_SIZE-1))) == NULL) {
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printf("allocation error \n");
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exit (-1);
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}
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if ((unsigned long)clk_mem % PAGE_SIZE)
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clk_mem += PAGE_SIZE - ((unsigned long)clk_mem % PAGE_SIZE);
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clk_map = (unsigned char *)mmap(
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(caddr_t)clk_mem,
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BLOCK_SIZE,
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PROT_READ|PROT_WRITE,
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MAP_SHARED|MAP_FIXED,
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mem_fd,
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CLOCK_BASE
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);
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if ((long)clk_map < 0) {
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printf("clk mmap error %d\n", (int)clk_map);
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exit (-1);
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}
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clk = (volatile unsigned *)clk_map;
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/*
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* mmap GPIO
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*/
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if ((gpio_mem = malloc(BLOCK_SIZE + (PAGE_SIZE-1))) == NULL) {
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printf("allocation error \n");
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exit (-1);
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}
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if ((unsigned long)gpio_mem % PAGE_SIZE)
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gpio_mem += PAGE_SIZE - ((unsigned long)gpio_mem % PAGE_SIZE);
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gpio_map = (unsigned char *)mmap(
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(caddr_t)gpio_mem,
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BLOCK_SIZE,
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PROT_READ|PROT_WRITE,
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MAP_SHARED|MAP_FIXED,
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mem_fd,
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GPIO_BASE
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);
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if ((long)gpio_map < 0) {
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printf("gpio mmap error %d\n", (int)gpio_map);
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exit (-1);
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}
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gpio = (volatile unsigned *)gpio_map;
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/*
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* mmap PWM
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*/
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if ((pwm_mem = malloc(BLOCK_SIZE + (PAGE_SIZE-1))) == NULL) {
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printf("allocation error \n");
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exit (-1);
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}
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if ((unsigned long)pwm_mem % PAGE_SIZE)
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pwm_mem += PAGE_SIZE - ((unsigned long)pwm_mem % PAGE_SIZE);
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pwm_map = (unsigned char *)mmap(
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(caddr_t)pwm_mem,
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BLOCK_SIZE,
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PROT_READ|PROT_WRITE,
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MAP_SHARED|MAP_FIXED,
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mem_fd,
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PWM_BASE
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);
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if ((long)pwm_map < 0) {
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printf("pwm mmap error %d\n", (int)pwm_map);
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exit (-1);
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}
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pwm = (volatile unsigned *)pwm_map;
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/*
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* mmap SPI0
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*/
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if ((spi0_mem = malloc(BLOCK_SIZE + (PAGE_SIZE-1))) == NULL) {
|
||
|
|
printf("allocation error \n");
|
||
|
|
exit (-1);
|
||
|
|
}
|
||
|
|
if ((unsigned long)spi0_mem % PAGE_SIZE)
|
||
|
|
spi0_mem += PAGE_SIZE - ((unsigned long)spi0_mem % PAGE_SIZE);
|
||
|
|
|
||
|
|
spi0_map = (unsigned char *)mmap(
|
||
|
|
(caddr_t)spi0_mem,
|
||
|
|
BLOCK_SIZE,
|
||
|
|
PROT_READ|PROT_WRITE,
|
||
|
|
MAP_SHARED|MAP_FIXED,
|
||
|
|
mem_fd,
|
||
|
|
SPI0_BASE
|
||
|
|
);
|
||
|
|
|
||
|
|
if ((long)spi0_map < 0) {
|
||
|
|
printf("spi0 mmap error %d\n", (int)spi0_map);
|
||
|
|
exit (-1);
|
||
|
|
}
|
||
|
|
spi0 = (volatile unsigned *)spi0_map;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* mmap UART
|
||
|
|
*/
|
||
|
|
if ((uart_mem = malloc(BLOCK_SIZE + (PAGE_SIZE-1))) == NULL) {
|
||
|
|
printf("allocation error \n");
|
||
|
|
exit (-1);
|
||
|
|
}
|
||
|
|
if ((unsigned long)uart_mem % PAGE_SIZE)
|
||
|
|
uart_mem += PAGE_SIZE - ((unsigned long)uart_mem % PAGE_SIZE);
|
||
|
|
|
||
|
|
uart_map = (unsigned char *)mmap(
|
||
|
|
(caddr_t)uart_mem,
|
||
|
|
BLOCK_SIZE,
|
||
|
|
PROT_READ|PROT_WRITE,
|
||
|
|
MAP_SHARED|MAP_FIXED,
|
||
|
|
mem_fd,
|
||
|
|
UART0_BASE
|
||
|
|
);
|
||
|
|
|
||
|
|
if ((long)uart_map < 0) {
|
||
|
|
printf("uart mmap error %d\n", (int)uart_map);
|
||
|
|
exit (-1);
|
||
|
|
}
|
||
|
|
uart = (volatile unsigned *)uart_map;
|
||
|
|
|
||
|
|
} // setup_io
|
||
|
|
|
||
|
|
//
|
||
|
|
// Undo what we did above
|
||
|
|
//
|
||
|
|
void restore_io()
|
||
|
|
{
|
||
|
|
munmap(uart_map,BLOCK_SIZE);
|
||
|
|
munmap(spi0_map,BLOCK_SIZE);
|
||
|
|
munmap(pwm_map,BLOCK_SIZE);
|
||
|
|
munmap(gpio_map,BLOCK_SIZE);
|
||
|
|
munmap(clk_map,BLOCK_SIZE);
|
||
|
|
// can't reliable return data
|
||
|
|
// as the pntr may have been moved to 4K boundary
|
||
|
|
// so leave it to OS to return the memory
|
||
|
|
// free(uart_mem);
|
||
|
|
// free(spi0_mem);
|
||
|
|
// free(pwm_mem);
|
||
|
|
// free(gpio_mem);
|
||
|
|
// free(clk_mem );
|
||
|
|
} // restore_io
|
||
|
|
|