1 // SPDX-License-Identifier: GPL-2.0-only
3  * GPIO tools - helpers library for the GPIO tools
17 #include <linux/gpio.h>
18 #include "gpio-utils.h"
20 #define CONSUMER "gpio-utils"
23  * DOC: Operation of gpio
27  * ioctl, including request and release for lines of gpio, read/write
28  * the value of gpio. If the user want to do lots of read and write of
29  * lines of gpio, user should use this type of api.
32  * following api will request gpio lines, do the operation and then
37  * gpiotools_request_line() - request gpio lines in a gpiochip
41  *			index for the associated GPIO device.
43  * @config:		The new config for requested gpio. Reference
44  *			"linux/gpio.h" for config details.
49  * Request gpio lines through the ioctl provided by chardev. User
59 			   struct gpio_v2_line_config *config,  in gpiotools_request_line()  argument
70 		return -ENOMEM;  in gpiotools_request_line()
73 	if (fd == -1) {  in gpiotools_request_line()
74 		ret = -errno;  in gpiotools_request_line()
84 	req.config = *config;  in gpiotools_request_line()
89 	if (ret == -1) {  in gpiotools_request_line()
90 		ret = -errno;  in gpiotools_request_line()
95 	if (close(fd) == -1)  in gpiotools_request_line()
96 		perror("Failed to close GPIO character device file");  in gpiotools_request_line()
103  * gpiotools_set_values() - Set the value of gpio(s)
116 	if (ret == -1) {  in gpiotools_set_values()
117 		ret = -errno;  in gpiotools_set_values()
127  * gpiotools_get_values() - Get the value of gpio(s)
140 	if (ret == -1) {  in gpiotools_get_values()
141 		ret = -errno;  in gpiotools_get_values()
151  * gpiotools_release_line() - Release the line(s) of gpiochip
163 	if (ret == -1) {  in gpiotools_release_line()
164 		perror("Failed to close GPIO LINE device file");  in gpiotools_release_line()
165 		ret = -errno;  in gpiotools_release_line()
172  * gpiotools_get() - Get value from specific line
194  * gpiotools_gets() - Get values from specific lines.
198  *			index for the associated GPIO device.
211 	struct gpio_v2_line_config config;  in gpiotools_gets()  local
214 	memset(&config, 0, sizeof(config));  in gpiotools_gets()
215 	config.flags = GPIO_V2_LINE_FLAG_INPUT;  in gpiotools_gets()
217 				     &config, CONSUMER);  in gpiotools_gets()
233  * gpiotools_set() - Set value to specific line
237  * @value:		The value of gpio, must be 0(low) or 1(high).
251  * gpiotools_sets() - Set values to specific lines.
255  *			index for the associated GPIO device.
267 	struct gpio_v2_line_config config;  in gpiotools_sets()  local
269 	memset(&config, 0, sizeof(config));  in gpiotools_sets()
270 	config.flags = GPIO_V2_LINE_FLAG_OUTPUT;  in gpiotools_sets()
271 	config.num_attrs = 1;  in gpiotools_sets()
272 	config.attrs[0].attr.id = GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES;  in gpiotools_sets()
274 		gpiotools_set_bit(&config.attrs[0].mask, i);  in gpiotools_sets()
275 		gpiotools_assign_bit(&config.attrs[0].attr.values,  in gpiotools_sets()
279 				     &config, CONSUMER);  in gpiotools_sets()