mirror of https://gitee.com/openkylin/linux.git
tools/gpio: add gpio basic opereations
Add basic gpio operations. User could get/set gpio value for specific line of gpiochip. Reference "tools/gpio/gpio-hammer.c" or "tools/testing/selftest/gpio/gpio-mockup-chardev.c" for how to use it. Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> Reviewed-by: Michael Welling <mwelling@ieee.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Bamvor Jian Zhang
Linus Walleij
parent
26a48c4cc2
commit
e1acec0e75
|
|
@ -2,10 +2,266 @@
|
|||
* GPIO tools - helpers library for the GPIO tools
|
||||
*
|
||||
* Copyright (C) 2015 Linus Walleij
|
||||
* Copyright (C) 2016 Bamvor Jian Zhang
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 as published by
|
||||
* the Free Software Foundation.
|
||||
*/
|
||||
|
||||
#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 COMSUMER "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_linehandle() - 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.
|
||||
* @nline: The number of lines to request.
|
||||
* @flag: The new flag for requsted gpio. Reference
|
||||
* "linux/gpio.h" for the meaning of flag.
|
||||
* @data: Default value will be set to gpio when flag is
|
||||
* GPIOHANDLE_REQUEST_OUTPUT.
|
||||
* @consumer_label: 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_linehandle() to release these lines after that.
|
||||
*
|
||||
* Return: On success return the fd;
|
||||
* On failure return the errno.
|
||||
*/
|
||||
int gpiotools_request_linehandle(const char *device_name, unsigned int *lines,
|
||||
unsigned int nlines, unsigned int flag,
|
||||
struct gpiohandle_data *data,
|
||||
const char *consumer_label)
|
||||
{
|
||||
struct gpiohandle_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\n", chrdev_name);
|
||||
goto exit_close_error;
|
||||
}
|
||||
|
||||
for (i = 0; i < nlines; i++)
|
||||
req.lineoffsets[i] = lines[i];
|
||||
|
||||
req.flags = flag;
|
||||
strcpy(req.consumer_label, consumer_label);
|
||||
req.lines = nlines;
|
||||
if (flag & GPIOHANDLE_REQUEST_OUTPUT)
|
||||
memcpy(req.default_values, data, sizeof(req.default_values));
|
||||
|
||||
ret = ioctl(fd, GPIO_GET_LINEHANDLE_IOCTL, &req);
|
||||
if (ret == -1) {
|
||||
ret = -errno;
|
||||
fprintf(stderr, "Failed to issue GET LINEHANDLE IOCTL (%d)\n",
|
||||
ret);
|
||||
}
|
||||
|
||||
exit_close_error:
|
||||
if (close(fd) == -1)
|
||||
perror("Failed to close GPIO character device file");
|
||||
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_linehandle().
|
||||
* @data: 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 gpiohandle_data *data)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = ioctl(fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, data);
|
||||
if (ret == -1) {
|
||||
ret = -errno;
|
||||
fprintf(stderr, "Failed to issue %s (%d)\n",
|
||||
"GPIOHANDLE_SET_LINE_VALUES_IOCTL", ret);
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* gpiotools_get_values(): Get the value of gpio(s)
|
||||
* @fd: The fd returned by
|
||||
* gpiotools_request_linehandle().
|
||||
* @data: 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 gpiohandle_data *data)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = ioctl(fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, data);
|
||||
if (ret == -1) {
|
||||
ret = -errno;
|
||||
fprintf(stderr, "Failed to issue %s (%d)\n",
|
||||
"GPIOHANDLE_GET_LINE_VALUES_IOCTL", ret);
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* gpiotools_release_linehandle(): Release the line(s) of gpiochip
|
||||
* @fd: The fd returned by
|
||||
* gpiotools_request_linehandle().
|
||||
*
|
||||
* Return: On success return 0;
|
||||
* On failure return the errno.
|
||||
*/
|
||||
int gpiotools_release_linehandle(const int fd)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = close(fd);
|
||||
if (ret == -1) {
|
||||
perror("Failed to close GPIO LINEHANDLE 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)
|
||||
{
|
||||
struct gpiohandle_data data;
|
||||
unsigned int lines[] = {line};
|
||||
|
||||
gpiotools_gets(device_name, lines, 1, &data);
|
||||
return data.values[0];
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* 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.
|
||||
* @nline: The number of lines to request.
|
||||
* @data: 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 nlines, struct gpiohandle_data *data)
|
||||
{
|
||||
int fd;
|
||||
int ret;
|
||||
int ret_close;
|
||||
|
||||
ret = gpiotools_request_linehandle(device_name, lines, nlines,
|
||||
GPIOHANDLE_REQUEST_INPUT, data,
|
||||
COMSUMER);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
fd = ret;
|
||||
ret = gpiotools_get_values(fd, data);
|
||||
ret_close = gpiotools_release_linehandle(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)
|
||||
{
|
||||
struct gpiohandle_data data;
|
||||
unsigned int lines[] = {line};
|
||||
|
||||
data.values[0] = value;
|
||||
return gpiotools_sets(device_name, lines, 1, &data);
|
||||
}
|
||||
|
||||
/**
|
||||
* 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.
|
||||
* @nline: The number of lines to request.
|
||||
* @data: 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 nlines, struct gpiohandle_data *data)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = gpiotools_request_linehandle(device_name, lines, nlines,
|
||||
GPIOHANDLE_REQUEST_OUTPUT, data,
|
||||
COMSUMER);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return gpiotools_release_linehandle(ret);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -24,4 +24,20 @@ static inline int check_prefix(const char *str, const char *prefix)
|
|||
strncmp(str, prefix, strlen(prefix)) == 0;
|
||||
}
|
||||
|
||||
int gpiotools_request_linehandle(const char *device_name, unsigned int *lines,
|
||||
unsigned int nlines, unsigned int flag,
|
||||
struct gpiohandle_data *data,
|
||||
const char *consumer_label);
|
||||
int gpiotools_set_values(const int fd, struct gpiohandle_data *data);
|
||||
int gpiotools_get_values(const int fd, struct gpiohandle_data *data);
|
||||
int gpiotools_release_linehandle(const int fd);
|
||||
|
||||
int gpiotools_get(const char *device_name, unsigned int line);
|
||||
int gpiotools_gets(const char *device_name, unsigned int *lines,
|
||||
unsigned int nlines, struct gpiohandle_data *data);
|
||||
int gpiotools_set(const char *device_name, unsigned int line,
|
||||
unsigned int value);
|
||||
int gpiotools_sets(const char *device_name, unsigned int *lines,
|
||||
unsigned int nlines, struct gpiohandle_data *data);
|
||||
|
||||
#endif /* _GPIO_UTILS_H_ */
|
||||
|
|
|
|||
Loading…
Reference in New Issue