linux: userspace GPIO control

Allow use host GPIO pins for non-realtime purposes.

Signed-off-by: Andrey Kunitsyn <blackicebox@gmail.com>

9 files changed, 186 insertions, 22 deletions

diff --git a/src/linux/Kconfig b/src/linux/Kconfig
index f4b51ffa..edf575b0 100644
--- a/src/linux/Kconfig
+++ b/src/linux/Kconfig
@@ -10,6 +10,8 @@ config LINUX_SELECT
     select HAVE_GPIO_SPI
     select HAVE_GPIO_HARD_PWM
     select HAVE_GPIO_I2C
+    select HAVE_GPIO_BITBANGING
+    select HAVE_GPIO
 
 config BOARD_DIRECTORY
     string
diff --git a/src/linux/Makefile b/src/linux/Makefile
index 5cc9c69a..db3c913a 100644
--- a/src/linux/Makefile
+++ b/src/linux/Makefile
@@ -4,7 +4,7 @@ dirs-y += src/linux src/generic
 
 src-y += linux/main.c linux/timer.c linux/console.c linux/watchdog.c
 src-y += linux/pca9685.c linux/spidev.c linux/analog.c linux/hard_pwm.c
-src-y += linux/i2c.c generic/crc16_ccitt.c generic/alloc.c
+src-y += linux/i2c.c linux/gpio.c generic/crc16_ccitt.c generic/alloc.c
 
 CFLAGS_klipper.elf += -lutil
 
diff --git a/src/linux/analog.c b/src/linux/analog.c
index 2ce085a8..aa8fb701 100644
--- a/src/linux/analog.c
+++ b/src/linux/analog.c
@@ -15,15 +15,17 @@
 
 DECL_CONSTANT("ADC_MAX", 4095); // Assume 12bit adc
 
-DECL_ENUMERATION_RANGE("pin", "analog0", 0, 8);
+#define ANALOG_START (1<<8)
+
+DECL_ENUMERATION_RANGE("pin", "analog0", ANALOG_START, 8);
 
 #define IIO_PATH "/sys/bus/iio/devices/iio:device0/in_voltage%d_raw"
 
 struct gpio_adc
-gpio_adc_setup(uint8_t pin)
+gpio_adc_setup(uint32_t pin)
 {
     char fname[256];
-    snprintf(fname, sizeof(fname), IIO_PATH, pin);
+    snprintf(fname, sizeof(fname), IIO_PATH, pin-ANALOG_START);
 
     int fd = open(fname, O_RDONLY|O_CLOEXEC);
     if (fd < 0) {
diff --git a/src/linux/console.c b/src/linux/console.c
index 4afa6151..1c02b7a1 100644
--- a/src/linux/console.c
+++ b/src/linux/console.c
@@ -53,7 +53,7 @@ set_non_blocking(int fd)
     return 0;
 }
 
-static int
+int
 set_close_on_exec(int fd)
 {
     int ret = fcntl(fd, F_SETFD, FD_CLOEXEC);
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];
+}
diff --git a/src/linux/gpio.h b/src/linux/gpio.h
index 32e76bf5..e6ef86bd 100644
--- a/src/linux/gpio.h
+++ b/src/linux/gpio.h
@@ -4,17 +4,25 @@
 #include <stdint.h> // uint8_t
 
 struct gpio_out {
-    uint32_t pin;
+    struct gpio_line* line;
 };
-struct gpio_out gpio_out_setup(uint8_t pin, uint8_t val);
+struct gpio_out gpio_out_setup(uint32_t pin, uint8_t val);
+void gpio_out_reset(struct gpio_out g, uint8_t val);
 void gpio_out_toggle_noirq(struct gpio_out g);
 void gpio_out_toggle(struct gpio_out g);
 void gpio_out_write(struct gpio_out g, uint8_t val);
 
+struct gpio_in {
+    struct gpio_line* line;
+};
+struct gpio_in gpio_in_setup(uint32_t pin, int8_t pull_up);
+void gpio_in_reset(struct gpio_in g, int8_t pull_up);
+uint8_t gpio_in_read(struct gpio_in g);
+
 struct gpio_adc {
     int fd;
 };
-struct gpio_adc gpio_adc_setup(uint8_t pin);
+struct gpio_adc gpio_adc_setup(uint32_t pin);
 uint32_t gpio_adc_sample(struct gpio_adc g);
 uint16_t gpio_adc_read(struct gpio_adc g);
 void gpio_adc_cancel_sample(struct gpio_adc g);
@@ -32,7 +40,7 @@ struct gpio_pwm {
     int fd;
     uint32_t period;
 };
-struct gpio_pwm gpio_pwm_setup(uint8_t pin, uint32_t cycle_time, uint16_t val);
+struct gpio_pwm gpio_pwm_setup(uint32_t pin, uint32_t cycle_time, uint16_t val);
 void gpio_pwm_write(struct gpio_pwm g, uint16_t val);
 
 struct i2c_config {
diff --git a/src/linux/hard_pwm.c b/src/linux/hard_pwm.c
index f14b844b..cfe8b436 100644
--- a/src/linux/hard_pwm.c
+++ b/src/linux/hard_pwm.c
@@ -37,7 +37,7 @@ DECL_ENUMERATION_RANGE("pin", "pwmchip7/pwm0", HARD_PWM(7, 0), 16);
 #define PWM_PATH "/sys/class/pwm/pwmchip%u/pwm%u/%s"
 #define PWM_PATH_BB "/sys/class/pwm/pwm-%u:%u/%s"
 
-struct gpio_pwm gpio_pwm_setup(uint8_t pin, uint32_t cycle_time, uint16_t val)
+struct gpio_pwm gpio_pwm_setup(uint32_t pin, uint32_t cycle_time, uint16_t val)
 {
     char filename[256];
     char scratch[16];
diff --git a/src/linux/internal.h b/src/linux/internal.h
index b47426b3..592c4588 100644
--- a/src/linux/internal.h
+++ b/src/linux/internal.h
@@ -11,6 +11,7 @@
 // console.c
 void report_errno(char *where, int rc);
 int set_non_blocking(int fd);
+int set_close_on_exec(int fd);
 int console_setup(char *name);
 void console_sleep(struct timespec ts);
 
diff --git a/src/linux/spidev.c b/src/linux/spidev.c
index 764541e3..166db395 100644
--- a/src/linux/spidev.c
+++ b/src/linux/spidev.c
@@ -107,15 +107,3 @@ spi_transfer(struct spi_config config, uint8_t receive_data
         }
     }
 }
-
-// Dummy versions of gpio_out functions
-struct gpio_out
-gpio_out_setup(uint8_t pin, uint8_t val)
-{
-    shutdown("gpio_out_setup not supported");
-}
-
-void
-gpio_out_write(struct gpio_out g, uint8_t val)
-{
-}