1 files changed, 284 insertions, 0 deletions
diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c
new file mode 100644
index 000000000..4096bcd51
--- /dev/null
+++ b/tools/gpio/gpio-utils.c
@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GPIO tools - helpers library for the GPIO tools
+ *
+ * Copyright (C) 2015 Linus Walleij
+ * Copyright (C) 2016 Bamvor Jian Zhang
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <sys/ioctl.h>
+#include <linux/gpio.h>
+#include "gpio-utils.h"
+
+#define CONSUMER "gpio-utils"
+
+/**
+ * DOC: Operation of gpio
+ *
+ * Provide the api of gpiochip for chardev interface. There are two
+ * types of api.  The first one provide as same function as each
+ * ioctl, including request and release for lines of gpio, read/write
+ * the value of gpio. If the user want to do lots of read and write of
+ * lines of gpio, user should use this type of api.
+ *
+ * The second one provide the easy to use api for user. Each of the
+ * following api will request gpio lines, do the operation and then
+ * release these lines.
+ */
+
+/**
+ * gpiotools_request_line() - request gpio lines in a gpiochip
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0"
+ * @lines:		An array desired lines, specified by offset
+ *			index for the associated GPIO device.
+ * @num_lines:		The number of lines to request.
+ * @config:		The new config for requested gpio. Reference
+ *			"linux/gpio.h" for config details.
+ * @consumer:		The name of consumer, such as "sysfs",
+ *			"powerkey". This is useful for other users to
+ *			know who is using.
+ *
+ * Request gpio lines through the ioctl provided by chardev. User
+ * could call gpiotools_set_values() and gpiotools_get_values() to
+ * read and write respectively through the returned fd. Call
+ * gpiotools_release_line() to release these lines after that.
+ *
+ * Return:		On success return the fd;
+ *			On failure return the errno.
+ */
+int gpiotools_request_line(const char *device_name, unsigned int *lines,
+			   unsigned int num_lines,
+			   struct gpio_v2_line_config *config,
+			   const char *consumer)
+{
+	struct gpio_v2_line_request req;
+	char *chrdev_name;
+	int fd;
+	int i;
+	int ret;
+
+	ret = asprintf(&chrdev_name, "/dev/%s", device_name);
+	if (ret < 0)
+		return -ENOMEM;
+
+	fd = open(chrdev_name, 0);
+	if (fd == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to open %s, %s\n",
+			chrdev_name, strerror(errno));
+		goto exit_free_name;
+	}
+
+	memset(&req, 0, sizeof(req));
+	for (i = 0; i < num_lines; i++)
+		req.offsets[i] = lines[i];
+
+	req.config = *config;
+	strcpy(req.consumer, consumer);
+	req.num_lines = num_lines;
+
+	ret = ioctl(fd, GPIO_V2_GET_LINE_IOCTL, &req);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue %s (%d), %s\n",
+			"GPIO_GET_LINE_IOCTL", ret, strerror(errno));
+	}
+
+	if (close(fd) == -1)
+		perror("Failed to close GPIO character device file");
+exit_free_name:
+	free(chrdev_name);
+	return ret < 0 ? ret : req.fd;
+}
+
+/**
+ * gpiotools_set_values() - Set the value of gpio(s)
+ * @fd:			The fd returned by
+ *			gpiotools_request_line().
+ * @values:		The array of values want to set.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_set_values(const int fd, struct gpio_v2_line_values *values)
+{
+	int ret;
+
+	ret = ioctl(fd, GPIO_V2_LINE_SET_VALUES_IOCTL, values);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue %s (%d), %s\n",
+			"GPIOHANDLE_SET_LINE_VALUES_IOCTL", ret,
+			strerror(errno));
+	}
+
+	return ret;
+}
+
+/**
+ * gpiotools_get_values() - Get the value of gpio(s)
+ * @fd:			The fd returned by
+ *			gpiotools_request_line().
+ * @values:		The array of values get from hardware.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_get_values(const int fd, struct gpio_v2_line_values *values)
+{
+	int ret;
+
+	ret = ioctl(fd, GPIO_V2_LINE_GET_VALUES_IOCTL, values);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue %s (%d), %s\n",
+			"GPIOHANDLE_GET_LINE_VALUES_IOCTL", ret,
+			strerror(errno));
+	}
+
+	return ret;
+}
+
+/**
+ * gpiotools_release_line() - Release the line(s) of gpiochip
+ * @fd:			The fd returned by
+ *			gpiotools_request_line().
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_release_line(const int fd)
+{
+	int ret;
+
+	ret = close(fd);
+	if (ret == -1) {
+		perror("Failed to close GPIO LINE device file");
+		ret = -errno;
+	}
+
+	return ret;
+}
+
+/**
+ * gpiotools_get() - Get value from specific line
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0"
+ * @line:		number of line, such as 2.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_get(const char *device_name, unsigned int line)
+{
+	int ret;
+	unsigned int value;
+	unsigned int lines[] = {line};
+
+	ret = gpiotools_gets(device_name, lines, 1, &value);
+	if (ret)
+		return ret;
+	return value;
+}
+
+
+/**
+ * gpiotools_gets() - Get values from specific lines.
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0".
+ * @lines:		An array desired lines, specified by offset
+ *			index for the associated GPIO device.
+ * @num_lines:		The number of lines to request.
+ * @values:		The array of values get from gpiochip.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_gets(const char *device_name, unsigned int *lines,
+		   unsigned int num_lines, unsigned int *values)
+{
+	int fd, i;
+	int ret;
+	int ret_close;
+	struct gpio_v2_line_config config;
+	struct gpio_v2_line_values lv;
+
+	memset(&config, 0, sizeof(config));
+	config.flags = GPIO_V2_LINE_FLAG_INPUT;
+	ret = gpiotools_request_line(device_name, lines, num_lines,
+				     &config, CONSUMER);
+	if (ret < 0)
+		return ret;
+
+	fd = ret;
+	for (i = 0; i < num_lines; i++)
+		gpiotools_set_bit(&lv.mask, i);
+	ret = gpiotools_get_values(fd, &lv);
+	if (!ret)
+		for (i = 0; i < num_lines; i++)
+			values[i] = gpiotools_test_bit(lv.bits, i);
+	ret_close = gpiotools_release_line(fd);
+	return ret < 0 ? ret : ret_close;
+}
+
+/**
+ * gpiotools_set() - Set value to specific line
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0"
+ * @line:		number of line, such as 2.
+ * @value:		The value of gpio, must be 0(low) or 1(high).
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_set(const char *device_name, unsigned int line,
+		  unsigned int value)
+{
+	unsigned int lines[] = {line};
+
+	return gpiotools_sets(device_name, lines, 1, &value);
+}
+
+/**
+ * gpiotools_sets() - Set values to specific lines.
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0".
+ * @lines:		An array desired lines, specified by offset
+ *			index for the associated GPIO device.
+ * @num_lines:		The number of lines to request.
+ * @values:		The array of values set to gpiochip, must be
+ *			0(low) or 1(high).
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_sets(const char *device_name, unsigned int *lines,
+		   unsigned int num_lines, unsigned int *values)
+{
+	int ret, i;
+	struct gpio_v2_line_config config;
+
+	memset(&config, 0, sizeof(config));
+	config.flags = GPIO_V2_LINE_FLAG_OUTPUT;
+	config.num_attrs = 1;
+	config.attrs[0].attr.id = GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES;
+	for (i = 0; i < num_lines; i++) {
+		gpiotools_set_bit(&config.attrs[0].mask, i);
+		gpiotools_assign_bit(&config.attrs[0].attr.values,
+				     i, values[i]);
+	}
+	ret = gpiotools_request_line(device_name, lines, num_lines,
+				     &config, CONSUMER);
+	if (ret < 0)
+		return ret;
+
+	return gpiotools_release_line(ret);
+}