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
36  * gpiotools_request_linehandle() - request gpio lines in a gpiochip
40  *			index for the associated GPIO device.
42  * @flag:		The new flag for requsted gpio. Reference
43  *			"linux/gpio.h" for the meaning of flag.
44  * @data:		Default value will be set to gpio when flag is
50  * Request gpio lines through the ioctl provided by chardev. User
71 		return -ENOMEM;  in gpiotools_request_linehandle()
74 	if (fd == -1) {  in gpiotools_request_linehandle()
75 		ret = -errno;  in gpiotools_request_linehandle()
91 	if (ret == -1) {  in gpiotools_request_linehandle()
92 		ret = -errno;  in gpiotools_request_linehandle()
97 	if (close(fd) == -1)  in gpiotools_request_linehandle()
98 		perror("Failed to close GPIO character device file");  in gpiotools_request_linehandle()
105  * gpiotools_request_line() - request gpio lines in a gpiochip
109  *			index for the associated GPIO device.
111  * @config:		The new config for requested gpio. Reference
112  *			"linux/gpio.h" for config details.
117  * Request gpio lines through the ioctl provided by chardev. User
127 			   struct gpio_v2_line_config *config,  in gpiotools_request_line()  argument
138 		return -ENOMEM;  in gpiotools_request_line()
141 	if (fd == -1) {  in gpiotools_request_line()
142 		ret = -errno;  in gpiotools_request_line()
152 	req.config = *config;  in gpiotools_request_line()
157 	if (ret == -1) {  in gpiotools_request_line()
158 		ret = -errno;  in gpiotools_request_line()
163 	if (close(fd) == -1)  in gpiotools_request_line()
164 		perror("Failed to close GPIO character device file");  in gpiotools_request_line()
171  * gpiotools_set_values(): Set the value of gpio(s)
184 	if (ret == -1) {  in gpiotools_set_values()
185 		ret = -errno;  in gpiotools_set_values()
195  * gpiotools_get_values(): Get the value of gpio(s)
208 	if (ret == -1) {  in gpiotools_get_values()
209 		ret = -errno;  in gpiotools_get_values()
231 	if (ret == -1) {  in gpiotools_release_linehandle()
232 		perror("Failed to close GPIO LINEHANDLE device file");  in gpiotools_release_linehandle()
233 		ret = -errno;  in gpiotools_release_linehandle()
252 	if (ret == -1) {  in gpiotools_release_line()
253 		perror("Failed to close GPIO LINE device file");  in gpiotools_release_line()
254 		ret = -errno;  in gpiotools_release_line()
287  *			index for the associated GPIO device.
300 	struct gpio_v2_line_config config;  in gpiotools_gets()  local
303 	memset(&config, 0, sizeof(config));  in gpiotools_gets()
304 	config.flags = GPIO_V2_LINE_FLAG_INPUT;  in gpiotools_gets()
306 				     &config, CONSUMER);  in gpiotools_gets()
326  * @value:		The value of gpio, must be 0(low) or 1(high).
344  *			index for the associated GPIO device.
356 	struct gpio_v2_line_config config;  in gpiotools_sets()  local
358 	memset(&config, 0, sizeof(config));  in gpiotools_sets()
359 	config.flags = GPIO_V2_LINE_FLAG_OUTPUT;  in gpiotools_sets()
360 	config.num_attrs = 1;  in gpiotools_sets()
361 	config.attrs[0].attr.id = GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES;  in gpiotools_sets()
363 		gpiotools_set_bit(&config.attrs[0].mask, i);  in gpiotools_sets()
364 		gpiotools_assign_bit(&config.attrs[0].attr.values,  in gpiotools_sets()
368 				     &config, CONSUMER);  in gpiotools_sets()