#include <AP_HAL/AP_HAL.h> #if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF || \ CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_ERLEBOARD || \ CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI || \ CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BLUE || \ CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_POCKET #include "GPIO.h" #include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include <poll.h> #include <sys/mman.h> #include <sys/stat.h> using namespace Linux; GPIO_BBB::GPIO_BBB() {} void GPIO_BBB::init() { #if LINUX_GPIO_NUM_BANKS == 4 int mem_fd; // Enable all GPIO banks // Without this, access to deactivated banks (i.e. those with no clock source set up) will (logically) fail with SIGBUS // Idea taken from https://groups.google.com/forum/#!msg/beagleboard/OYFp4EXawiI/Mq6s3sg14HoJ uint8_t bank_enable[3] = { 5, 65, 105 }; int export_fd = open("/sys/class/gpio/export", O_WRONLY | O_CLOEXEC); if (export_fd == -1) { AP_HAL::panic("unable to open /sys/class/gpio/export"); } for (uint8_t i=0; i<3; i++) { dprintf(export_fd, "%u\n", (unsigned)bank_enable[i]); } close(export_fd); /* open /dev/mem */ if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC|O_CLOEXEC)) < 0) { printf("can't open /dev/mem \n"); exit (-1); } /* mmap GPIO */ off_t offsets[LINUX_GPIO_NUM_BANKS] = { GPIO0_BASE, GPIO1_BASE, GPIO2_BASE, GPIO3_BASE }; for (uint8_t i=0; i<LINUX_GPIO_NUM_BANKS; i++) { gpio_bank[i].base = (volatile unsigned *)mmap(0, GPIO_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, mem_fd, offsets[i]); if ((char *)gpio_bank[i].base == MAP_FAILED) { AP_HAL::panic("unable to map GPIO bank"); } gpio_bank[i].oe = gpio_bank[i].base + GPIO_OE; gpio_bank[i].in = gpio_bank[i].base + GPIO_IN; gpio_bank[i].out = gpio_bank[i].base + GPIO_OUT; } close(mem_fd); #endif // LINUX_GPIO_NUM_BANKS } void GPIO_BBB::pinMode(uint8_t pin, uint8_t output) { uint8_t bank = pin/32; uint8_t bankpin = pin & 0x1F; if (bank >= LINUX_GPIO_NUM_BANKS) { return; } if (output == HAL_GPIO_INPUT) { *gpio_bank[bank].oe |= (1U<<bankpin); } else { *gpio_bank[bank].oe &= ~(1U<<bankpin); } } uint8_t GPIO_BBB::read(uint8_t pin) { uint8_t bank = pin/32; uint8_t bankpin = pin & 0x1F; if (bank >= LINUX_GPIO_NUM_BANKS) { return 0; } return *gpio_bank[bank].in & (1U<<bankpin) ? HIGH : LOW; } void GPIO_BBB::write(uint8_t pin, uint8_t value) { uint8_t bank = pin/32; uint8_t bankpin = pin & 0x1F; if (bank >= LINUX_GPIO_NUM_BANKS) { return; } if (value == LOW) { *gpio_bank[bank].out &= ~(1U<<bankpin); } else { *gpio_bank[bank].out |= 1U<<bankpin; } } void GPIO_BBB::toggle(uint8_t pin) { write(pin, !read(pin)); } /* Alternative interface: */ AP_HAL::DigitalSource* GPIO_BBB::channel(uint16_t n) { return new DigitalSource(n); } bool GPIO_BBB::usb_connected(void) { return false; } #endif // CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF || // CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_ERLEBOARD || // CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI || // CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BLUE || // CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_POCKET