cpu/native: add Linux GPIO implementation

cpu/native/Kconfig

@@ -51,6 +51,8 @@ config NATIVE_OS_DARWIN
 
 config NATIVE_OS_LINUX
     bool
+    select HAS_PERIPH_GPIO
+    select HAS_PERIPH_GPIO_IRQ
     select HAS_PERIPH_SPI
 
 config NATIVE_OS_FREEBSD

cpu/native/Makefile.dep

@@ -1,6 +1,12 @@
-ifneq (,$(filter periph_spi,$(USEMODULE)))
-  USEMODULE += periph_spidev_linux
+ifeq ($(OS),Linux)
+  ifneq (,$(filter periph_gpio,$(USEMODULE)))
+    USEMODULE += periph_gpio_linux
+  endif
+  ifneq (,$(filter periph_spi,$(USEMODULE)))
+    USEMODULE += periph_spidev_linux
+  endif
 endif
+
 ifeq (,$(filter stdio_%,$(USEMODULE)))
   USEMODULE += stdio_native
 endif

cpu/native/Makefile.features

@@ -17,7 +17,9 @@ FEATURES_PROVIDED += periph_pm
 FEATURES_PROVIDED += periph_pwm
 FEATURES_PROVIDED += ssp
 
-# Access to hardware SPI bus is only supported on Linux hosts
 ifeq ($(OS),Linux)
+  # Access to hardware SPI bus is only supported on Linux hosts
   FEATURES_PROVIDED += periph_spi
+  # Hardware GPIO access is only available on Linux hosts
+  FEATURES_PROVIDED += periph_gpio periph_gpio_irq
 endif

cpu/native/include/gpiodev_linux.h

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2019 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for
+ * more details.
+ */
+
+/**
+ * @defgroup    drivers_gpio_linux Linux User Mode GPIO Driver
+ * @ingroup     cpu_native
+ * @brief       Implementation of GPIO access from Linux User Space
+ *
+ * This module allows to connect a RIOT application that runs on a Linux host to
+ * the physical GPIO pins of that host. To do so, the application has to be
+ * compiled for the native board in a Linux environment.
+ *
+ * GPIO support is automatically included if either a module requiring the
+ * `periph_gpio` feature is added to the application or if it is explicitly
+ * listed as `FEATURES_REQUIRED` in the application's Makefile.
+ *
+ * At runtime, the process has to be connected to a specific GPIO bank on the host
+ * machine. GPIO banks are exposed as `/dev/gpiochipN` character files, where N
+ * is the bank ID to which several GPIO pins are connected.
+ *
+ * Example:
+ *
+ * ```
+ * $ ./riot_native_app --gpio=/dev/gpiochip0 --gpio=/dev/gpiochip1
+ * ```
+ *
+ * This will add `/dev/gpiochip0` and `/dev/gpiochip1` as PORT(0) and PORT(1) in RIOT.
+ * The first pin can be used with PIN(0,0) as `gpio_t`, the second one on the first
+ * port would be PIN(0,1) and so on.
+ *
+ * Please refer to your board's documentation for the mapping of the pins.
+ *
+ * @{
+ *
+ * @file
+ * @brief       Implementation of GPIO access from Linux User Space
+ *
+ * @author      Benjamin Valentin <benpicco@googlemail.com>
+ */
+
+#ifndef GPIODEV_LINUX_H
+#define GPIODEV_LINUX_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   register `/dev/gpiochip*` device to be used for GPIO
+ *
+ * @param[in] device   The gpiochip device to open.
+ *
+ * @return             0 on success, error otherwise
+ */
+int gpio_linux_setup(const char* device);
+
+/**
+ * @brief   shutdown GPIO subsystem
+ *
+ * This closes all GPIO fds.
+ */
+void gpio_linux_teardown(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GPIODEV_LINUX_H */
+/** @} */

cpu/native/include/periph_cpu.h

@@ -32,6 +32,61 @@ extern "C" {
 #define CPUID_LEN           (4U)
 #endif
 
+/* GPIO configuration only if the module is available (=Linux) */
+#if defined(MODULE_PERIPH_GPIO_LINUX) || defined(DOXYGEN)
+#include <linux/gpio.h>
+
+/**
+ * @name GPIO Configuration
+ * @{
+ */
+
+/**
+ * @brief   The offset between Port and Pin
+ */
+#define GPIO_PORT_SHIFT     (24)
+
+/**
+ * @brief   Define a custom GPIO_PIN macro for native
+ */
+#define GPIO_PIN(port, pin) (gpio_t)((port << GPIO_PORT_SHIFT) | pin)
+
+#define HAVE_GPIO_MODE_T
+#ifndef GPIOHANDLE_REQUEST_PULL_DOWN
+#define GPIOHANDLE_REQUEST_PULL_DOWN    (0xFF)
+#endif
+#ifndef GPIOHANDLE_REQUEST_PULL_UP
+#define GPIOHANDLE_REQUEST_PULL_UP      (0xFF)
+#endif
+
+/**
+ * @brief   Available pin modes
+ *
+ * Generally, a pin can be configured to be input or output. In output mode, a
+ * pin can further be put into push-pull or open drain configuration. Though
+ * this is supported by most platforms, this is not always the case, so driver
+ * implementations may return an error code if a mode is not supported.
+ */
+typedef enum {
+    GPIO_IN    = GPIOHANDLE_REQUEST_INPUT,
+    GPIO_IN_PD = GPIOHANDLE_REQUEST_INPUT | GPIOHANDLE_REQUEST_PULL_DOWN,
+    GPIO_IN_PU = GPIOHANDLE_REQUEST_INPUT | GPIOHANDLE_REQUEST_PULL_UP,
+    GPIO_OUT   = GPIOHANDLE_REQUEST_OUTPUT,
+    GPIO_OD    = GPIOHANDLE_REQUEST_OPEN_DRAIN,
+    GPIO_OD_PU = GPIOHANDLE_REQUEST_OPEN_DRAIN | GPIOHANDLE_REQUEST_PULL_UP
+} gpio_mode_t;
+
+#define HAVE_GPIO_FLANK_T
+typedef enum {
+    GPIO_FALLING = GPIOEVENT_EVENT_FALLING_EDGE,    /**< emit interrupt on falling flank */
+    GPIO_RISING = GPIOEVENT_EVENT_RISING_EDGE,      /**< emit interrupt on rising flank */
+    GPIO_BOTH = GPIO_FALLING | GPIO_RISING          /**< emit interrupt on both flanks */
+} gpio_flank_t;
+
+/** @} */
+
+#endif /* MODULE_PERIPH_GPIO_LINUX | DOXYGEN */
+
 /**
  * @brief   Prevent shared timer functions from being used
  */

cpu/native/periph/gpio.c

@@ -19,6 +19,8 @@
 
 #include "periph/gpio.h"
 
+#ifndef MODULE_PERIPH_GPIO_LINUX
+
 int gpio_init(gpio_t pin, gpio_mode_t mode) {
   (void) pin;
   (void) mode;
@@ -51,4 +53,7 @@ void gpio_write(gpio_t pin, int value) {
   (void) pin;
   (void) value;
 }
+
+#endif /* !MODULE_PERIPH_GPIO_LINUX */
+
 /** @} */

cpu/native/periph/gpio_linux.c

@@ -0,0 +1,318 @@
+/*
+ * Copyright (C) 2019 Benjamin Valentin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for
+ * more details.
+ */
+
+/**
+ * @ingroup     cpu_native
+ * @ingroup     drivers_periph_gpio
+ * @{
+ *
+ * @file
+ * @brief       native GPIO implementation
+ *
+ * @author      Benjamin Valentin <benpicco@googlemail.com>
+ */
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/gpio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "native_internal.h"
+#include "periph/gpio.h"
+
+typedef struct {
+    gpio_cb_t cb;
+    void *arg;
+    bool enabled;
+} native_gpio_cb_t;
+
+typedef struct {
+    int fd;
+    unsigned num_pins;
+    int *pins;
+#ifdef MODULE_PERIPH_GPIO_IRQ
+    native_gpio_cb_t **cbs;
+#endif
+} native_port_t;
+
+static native_port_t *ports;
+static unsigned port_numof;
+
+#define _port(p)    (p >> GPIO_PORT_SHIFT)
+#define _pin(p)     (p & ((1 << GPIO_PORT_SHIFT) - 1))
+
+int gpio_linux_setup(const char* gpiochip)
+{
+    struct gpiochip_info info;
+    int fd = real_open(gpiochip, O_RDWR);
+
+    if (fd < 0) {
+        real_printf("GPIO: cannot open %s\n", gpiochip);
+        return fd;
+    }
+
+    if (real_ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &info) < 0) {
+        real_close(fd);
+        real_printf("GPIO: can not query %s\n", gpiochip);
+        return -ENODEV;
+    }
+
+    printf("GPIO: found %d pins on %s [%s]\n", info.lines, info.name, info.label);
+
+    void *tmp = reallocarray(ports, port_numof + 1, sizeof(*ports));
+
+    if (tmp == NULL) {
+        real_close(fd);
+        real_printf("GPIO: out of memory\n");
+        return -ENOMEM;
+    }
+
+    ports = tmp;
+    ports[port_numof].fd = fd;
+    ports[port_numof].num_pins = info.lines;
+    ports[port_numof].pins = calloc(info.lines, sizeof(*ports[0].pins));
+#ifdef MODULE_PERIPH_GPIO_IRQ
+    ports[port_numof].cbs = calloc(info.lines, sizeof(*ports[0].cbs));
+#endif
+    ++port_numof;
+
+    return 0;
+}
+
+void gpio_linux_teardown(void)
+{
+    for (unsigned i = 0; i < port_numof; ++i) {
+        for (unsigned j = 0; j < ports[i].num_pins; ++j) {
+
+            if (ports[i].pins[j] > 0) {
+                real_close(ports[i].pins[j]);
+            }
+#ifdef MODULE_PERIPH_GPIO_IRQ
+            if (ports[i].cbs[j]) {
+                real_free(ports[i].cbs[j]);
+            }
+#endif
+        }
+
+        if (ports[i].pins) {
+            real_free(ports[i].pins);
+        }
+
+        if (ports[i].fd) {
+            real_close(ports[i].fd);
+        }
+#ifdef MODULE_PERIPH_GPIO_IRQ
+        if (ports[i].cbs) {
+            real_free(ports[i].cbs);
+        }
+#endif
+    }
+
+    if (ports) {
+        real_free(ports);
+        ports = NULL;
+    }
+
+    port_numof = 0;
+}
+
+int gpio_init(gpio_t pin, gpio_mode_t mode)
+{
+    int res;
+    const unsigned p = _pin(pin);
+    struct gpiohandle_request req = {
+        .lineoffsets[0] = p,
+        .flags          = mode,
+        .lines          = 1
+    };
+    native_port_t *port;
+
+    if (mode == 0xFF) {
+        return -EINVAL;
+    }
+
+    if (_port(pin) >= port_numof) {
+        return -EINVAL;
+    }
+
+    port = &ports[_port(pin)];
+
+    if (p >= port->num_pins) {
+        return -EINVAL;
+    }
+
+    /* if the pin is already configured, close it first */
+    if (port->pins[p] > 0) {
+        real_close(port->pins[p]);
+        port->pins[p] = 0;
+    }
+
+    res = real_ioctl(port->fd, GPIO_GET_LINEHANDLE_IOCTL, &req);
+
+    if (res < 0) {
+        return res;
+    }
+
+    port->pins[p] = req.fd;
+    return 0;
+}
+
+int gpio_read(gpio_t pin)
+{
+    struct gpiohandle_data data;
+
+    if (_port(pin) >= port_numof) {
+        return -EINVAL;
+    }
+
+    int fd = ports[_port(pin)].pins[_pin(pin)];
+
+    if (fd <= 0) {
+        return -EINVAL;
+    }
+
+    real_ioctl(fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
+
+    return data.values[0];
+}
+
+static void _set(gpio_t pin, uint8_t val)
+{
+    int fd = ports[_port(pin)].pins[_pin(pin)];
+
+    if (fd > 0) {
+        real_ioctl(fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, &val);
+    }
+}
+
+void gpio_set(gpio_t pin)
+{
+    _set(pin, 1);
+}
+
+void gpio_clear(gpio_t pin)
+{
+    _set(pin, 0);
+}
+
+void gpio_toggle(gpio_t pin)
+{
+    _set(pin, !gpio_read(pin));
+}
+
+void gpio_write(gpio_t pin, int value)
+{
+    _set(pin, value);
+}
+
+#ifdef MODULE_PERIPH_GPIO_IRQ
+#include "async_read.h"
+
+static void _async_read_wrapper(int fd, void *arg) {
+    native_gpio_cb_t *cb = arg;
+
+    struct gpioevent_data event;
+    real_read(fd, &event, sizeof(event));
+
+    if (cb->cb && cb->enabled) {
+        cb->cb(cb->arg);
+    }
+
+    native_async_read_continue(fd);
+}
+
+int gpio_init_int(gpio_t pin, gpio_mode_t mode, gpio_flank_t flank,
+                  gpio_cb_t cb, void *arg)
+{
+    int res;
+    const unsigned p = _pin(pin);
+    struct gpioevent_request req = {
+        .lineoffset  = p,
+        .handleflags = mode,
+        .eventflags  = flank
+    };
+    native_port_t *port;
+
+    if (mode == 0xFF) {
+        return -EINVAL;
+    }
+
+    if (_port(pin) >= port_numof) {
+        return -EINVAL;
+    }
+
+    port = &ports[_port(pin)];
+
+    if (p >= port->num_pins) {
+        return -EINVAL;
+    }
+
+    /* if the pin is already configured, close it first */
+    if (port->pins[p] > 0) {
+        real_close(port->pins[p]);
+        port->pins[p] = 0;
+    }
+
+    res = real_ioctl(port->fd, GPIO_GET_LINEEVENT_IOCTL, &req);
+
+    if (res < 0) {
+        return res;
+    }
+
+    port->pins[p] = req.fd;
+
+    if (port->cbs[p] == NULL) {
+        port->cbs[p] = malloc(sizeof(native_gpio_cb_t));
+    }
+
+    port->cbs[p]->cb  = cb;
+    port->cbs[p]->arg = arg;
+    port->cbs[p]->enabled = true;
+
+    native_async_read_setup();
+    native_async_read_add_int_handler(req.fd, port->cbs[p], _async_read_wrapper);
+
+    return 0;
+}
+
+static void _set_irq_enabled(gpio_t pin, bool enabled)
+{
+    native_port_t *port;
+    const unsigned p = _pin(pin);
+
+    if (_port(pin) >= port_numof) {
+        return;
+    }
+
+    port = &ports[_port(pin)];
+
+    if (p >= port->num_pins) {
+        return;
+    }
+
+    port->cbs[p]->enabled = enabled;
+}
+
+void gpio_irq_enable(gpio_t pin)
+{
+    _set_irq_enabled(pin, true);
+}
+
+void gpio_irq_disable(gpio_t pin)
+{
+    _set_irq_enabled(pin, false);
+}
+
+#endif /* MODULE_PERIPH_GPIO_IRQ */
+
+/** @} */

cpu/native/periph/pm.c

@@ -27,9 +27,11 @@
 #include "tty_uart.h"
 
 #ifdef MODULE_PERIPH_SPIDEV_LINUX
-/* Only manage SPI if it is part of the build */
 #include "spidev_linux.h"
 #endif
+#ifdef MODULE_PERIPH_GPIO_LINUX
+#include "gpiodev_linux.h"
+#endif
 
 #define ENABLE_DEBUG (0)
 #include "debug.h"
@@ -51,6 +53,9 @@ void pm_off(void)
     puts("\nnative: exiting");
 #ifdef MODULE_PERIPH_SPIDEV_LINUX
     spidev_linux_teardown();
+#endif
+#ifdef MODULE_PERIPH_GPIO_LINUX
+    gpio_linux_teardown();
 #endif
     real_exit(EXIT_SUCCESS);
 }
@@ -63,6 +68,9 @@ void pm_reboot(void)
 #ifdef MODULE_PERIPH_SPIDEV_LINUX
     spidev_linux_teardown();
 #endif
+#ifdef MODULE_PERIPH_GPIO_LINUX
+    gpio_linux_teardown();
+#endif
 
     if (real_execve(_native_argv[0], _native_argv, NULL) == -1) {
         err(EXIT_FAILURE, "reboot: execve");

cpu/native/startup.c

@@ -81,6 +81,9 @@ netdev_tap_params_t netdev_tap_params[NETDEV_TAP_MAX];
 #ifdef MODULE_PERIPH_SPIDEV_LINUX
 #include "spidev_linux.h"
 #endif
+#ifdef MODULE_PERIPH_GPIO_LINUX
+#include "gpiodev_linux.h"
+#endif
 #ifdef MODULE_SOCKET_ZEP
 #include "socket_zep_params.h"
 
@@ -92,6 +95,9 @@ extern char eeprom_file[EEPROM_FILEPATH_MAX_LEN];
 #endif
 
 static const char short_opts[] = ":hi:s:deEoc:"
+#ifdef MODULE_PERIPH_GPIO_LINUX
+    "g:"
+#endif
 #ifdef MODULE_MTD_NATIVE
     "m:"
 #endif
@@ -115,6 +121,9 @@ static const struct option long_opts[] = {
     { "stderr-noredirect", no_argument, NULL, 'E' },
     { "stdout-pipe", no_argument, NULL, 'o' },
     { "uart-tty", required_argument, NULL, 'c' },
+#ifdef MODULE_PERIPH_GPIO_LINUX
+    { "gpio", required_argument, NULL, 'g' },
+#endif
 #ifdef MODULE_MTD_NATIVE
     { "mtd", required_argument, NULL, 'm' },
 #endif
@@ -260,6 +269,9 @@ void usage_exit(int status)
     }
 #endif
     real_printf(" [-i <id>] [-d] [-e|-E] [-o] [-c <tty>]\n");
+#ifdef MODULE_PERIPH_GPIO_LINUX
+    real_printf(" [-g <gpiochip>]\n");
+#endif
 #if defined(MODULE_SOCKET_ZEP) && (SOCKET_ZEP_MAX > 0)
     real_printf(" -z [[<laddr>:<lport>,]<raddr>:<rport>]\n");
     for (int i = 0; i < SOCKET_ZEP_MAX - 1; i++) {
@@ -295,6 +307,11 @@ void usage_exit(int status)
 "    -c <tty>, --uart-tty=<tty>\n"
 "        specify TTY device for UART. This argument can be used multiple\n"
 "        times (up to UART_NUMOF)\n"
+#ifdef MODULE_PERIPH_GPIO_LINUX
+"    -g <gpio>, --gpio=<gpio>\n"
+"        specify gpiochip device for GPIO access. This argument can be used multiple times.\n"
+"        Example: --gpio=/dev/gpiochip0 uses gpiochip0 for port 0\n"
+#endif
 #if defined(MODULE_SOCKET_ZEP) && (SOCKET_ZEP_MAX > 0)
 "    -z [<laddr>:<lport>,]<raddr>:<rport> --zep=[<laddr>:<lport>,]<raddr>:<rport>\n"
 "        provide a ZEP interface with local address and port (<laddr>, <lport>)\n"
@@ -463,6 +480,13 @@ __attribute__((constructor)) static void startup(int argc, char **argv, char **e
                 }
                 force_stderr = true;
                 break;
+#ifdef MODULE_PERIPH_GPIO_LINUX
+            case 'g':
+                if (gpio_linux_setup(optarg) < 0) {
+                    usage_exit(EXIT_FAILURE);
+                }
+                break;
+#endif
             case 'o':
                 stdouttype = _STDIOTYPE_FILE;
                 break;