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
33  * release these lines.
36  * gpiotools_request_linehandle() - request gpio lines in a gpiochip
39  * @lines:		An array desired lines, specified by offset
40  *			index for the associated GPIO device.
41  * @num_lines:		The number of lines to request.
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
53  * gpiotools_release_linehandle() to release these lines after that.
58 int gpiotools_request_linehandle(const char *device_name, unsigned int *lines,  in gpiotools_request_linehandle()  argument
71 		return -ENOMEM;  in gpiotools_request_linehandle()
74 	if (fd == -1) {  in gpiotools_request_linehandle()
75 		ret = -errno;  in gpiotools_request_linehandle()
82 		req.lineoffsets[i] = lines[i];  in gpiotools_request_linehandle()
86 	req.lines = num_lines;  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
108  * @lines:		An array desired lines, specified by offset
109  *			index for the associated GPIO device.
110  * @num_lines:		The number of lines to request.
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
120  * gpiotools_release_line() to release these lines after that.
125 int gpiotools_request_line(const char *device_name, unsigned int *lines,  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()
150 		req.offsets[i] = lines[i];  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()
273 	unsigned int lines[] = {line};  in gpiotools_get()  local
275 	ret = gpiotools_gets(device_name, lines, 1, &value);  in gpiotools_get()
283  * gpiotools_gets(): Get values from specific lines.
286  * @lines:		An array desired lines, specified by offset
287  *			index for the associated GPIO device.
288  * @num_lines:		The number of lines to request.
294 int gpiotools_gets(const char *device_name, unsigned int *lines,  in gpiotools_gets()  argument
305 	ret = gpiotools_request_line(device_name, lines, num_lines,  in gpiotools_gets()
326  * @value:		The value of gpio, must be 0(low) or 1(high).
334 	unsigned int lines[] = {line};  in gpiotools_set()  local
336 	return gpiotools_sets(device_name, lines, 1, &value);  in gpiotools_set()
340  * gpiotools_sets(): Set values to specific lines.
343  * @lines:		An array desired lines, specified by offset
344  *			index for the associated GPIO device.
345  * @num_lines:		The number of lines to request.
352 int gpiotools_sets(const char *device_name, unsigned int *lines,  in gpiotools_sets()  argument
367 	ret = gpiotools_request_line(device_name, lines, num_lines,  in gpiotools_sets()