diff options
Diffstat (limited to 'src/linux/gpio.c')
| -rw-r--r-- | src/linux/gpio.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/src/linux/gpio.c b/src/linux/gpio.c new file mode 100644 index 00000000..d8990581 --- /dev/null +++ b/src/linux/gpio.c @@ -0,0 +1,163 @@ +// Very basic support via a Linux gpiod device +// +// Copyright (C) 2017-2018 Kevin O'Connor <kevin@koconnor.net> +// +// This file may be distributed under the terms of the GNU GPLv3 license. +#include "autoconf.h" +#include "gpio.h" +#include "command.h" // shutdown +#include "sched.h" // shutdown + +#include <fcntl.h> // open +#include <stdio.h> // snprintf +#include <string.h> // memset +#include <stdlib.h> // atexit + +#include "internal.h" // report_errno + +#include </usr/include/linux/gpio.h> +#include <sys/ioctl.h> +#include <unistd.h> + +#define CHIP_FILE_NAME "/dev/gpiochip0" +#define GPIO_CONSUMER "klipper" +#define NUM_LINES 40 + +DECL_ENUMERATION_RANGE("pin", "P0", 0, NUM_LINES); + +struct gpio_line { + int offset; + int fd; + int state; +}; + +static struct gpio_line lines[NUM_LINES]; + +static int gpio_chip_fd = -1; + +static int +get_chip_fd(void) { + int i = 0; + if (gpio_chip_fd <= 0) { + gpio_chip_fd = open(CHIP_FILE_NAME,O_RDWR | O_CLOEXEC); + if (gpio_chip_fd < 0) { + report_errno("open " CHIP_FILE_NAME,-1); + shutdown("Unable to open GPIO chip device"); + } + for (i=0; i<NUM_LINES; ++i) { + lines[i].offset = i; + lines[i].fd = -1; + } + } + return gpio_chip_fd; +} + +// Dummy versions of gpio_out functions +struct gpio_out +gpio_out_setup(uint32_t pin, uint8_t val) +{ + struct gpio_line* line = &lines[pin]; + line->offset = pin; + struct gpio_out g = { .line = line }; + gpio_out_reset(g,val); + return g; +} + +static void +gpio_release_line(struct gpio_line* line) +{ + if (line->fd > 0) { + close(line->fd); + line->fd = -1; + } +} + +void +gpio_out_reset(struct gpio_out g, uint8_t val) +{ + int rv; + struct gpiohandle_request req; + gpio_release_line(g.line); + memset(&req, 0, sizeof(req)); + req.lines = 1; + req.flags = GPIOHANDLE_REQUEST_OUTPUT; + req.lineoffsets[0] = g.line->offset; + req.default_values[0] = !!val; + strncpy(req.consumer_label,GPIO_CONSUMER,sizeof(req.consumer_label) - 1); + rv = ioctl(get_chip_fd(), GPIO_GET_LINEHANDLE_IOCTL, &req); + if (rv < 0) { + report_errno("gpio_out_reset get line",rv); + shutdown("Unable to open out GPIO chip line"); + } + set_close_on_exec(req.fd); + g.line->fd = req.fd; + g.line->state = !!val; +} + +void +gpio_out_write(struct gpio_out g, uint8_t val) +{ + struct gpiohandle_data data; + memset(&data, 0, sizeof(data)); + data.values[0] = !!val; + ioctl(g.line->fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, &data); + g.line->state = !!val; +} + +void +gpio_out_toggle(struct gpio_out g) +{ + gpio_out_write(g,!g.line->state); +} + +void +gpio_out_toggle_noirq(struct gpio_out g) +{ + gpio_out_toggle(g); +} + +struct gpio_in +gpio_in_setup(uint32_t pin, int8_t pull_up) +{ + struct gpio_line* line = &lines[pin]; + line->offset = pin; + struct gpio_in g = { .line = line }; + gpio_in_reset(g,pull_up); + return g; +} + +void +gpio_in_reset(struct gpio_in g, int8_t pull_up) +{ + int rv; + struct gpiohandle_request req; + gpio_release_line(g.line); + memset(&req, 0, sizeof(req)); + req.lines = 1; + req.flags = GPIOHANDLE_REQUEST_INPUT; +#if defined(GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP) + if (pull_up > 0) { + req.flags |= GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP; + } else if (pull_up < 0) { + req.flags |= GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_DOWN; + } +#endif + req.lineoffsets[0] = g.line->offset; + strncpy(req.consumer_label,GPIO_CONSUMER,sizeof(req.consumer_label) - 1); + rv = ioctl(get_chip_fd(), GPIO_GET_LINEHANDLE_IOCTL, &req); + if (rv < 0) { + report_errno("gpio_in_reset get line",rv); + shutdown("Unable to open in GPIO chip line"); + } + set_close_on_exec(req.fd); + g.line->fd = req.fd; +} + +uint8_t +gpio_in_read(struct gpio_in g) +{ + struct gpiohandle_data data; + memset(&data, 0, sizeof(data)); + ioctl(g.line->fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data); + return data.values[0]; +} |