| Message ID | 20160831094548.12574-2-bamvor.zhangjian@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Wed, Aug 31, 2016 at 2:45 AM, <bamvor.zhangjian@linaro.org> wrote: > +int gpio_request(const char *device_name, unsigned int *lines, > + unsigned int nlines, unsigned int flag, > + struct gpiohandle_data *data, const char *consumer_label) Could it be named gpiotools_request_linehandle()? Or the name is maybe a bit long. It's nice if we have a name that tells all the function is doing. > +int gpio_set_values(const int fd, struct gpiohandle_data *data) Pls rename gpiotools_set_values() > +int gpio_get_values(const int fd, struct gpiohandle_data *data) Pls rename gpiotools_get_values() > +int gpio_release(const int fd) Pls rename gpiotools_release_linehandle() > +int gpio_gets(const char *device_name, unsigned int *lines, unsigned int nlines, > + unsigned int flag, struct gpiohandle_data *data) > +int gpio_sets(const char *device_name, unsigned int *lines, unsigned int nlines, > + unsigned int flag, struct gpiohandle_data *data) > +int gpio_get(const char *device_name, unsigned int line, unsigned int flag) > +int gpio_set(const char *device_name, unsigned int line, unsigned int flag, > + unsigned int value) > +int gpio_set_flag(const char *device_name, unsigned int line, unsigned int flag) Prefix all gpiotools_* > +/* > + * Request the lines for gpio with device_name. Could set the default value > + * in request. > + * device_name: the name of gpiochip in "/dev", such as gpiochip0. > + * lines: the array of which line should be requested. > + * nline: the total number of line > + * flag: input, output and so on. Reference "linux/gpio.h" for the > + * meaning for flag. > + * data: default value when flag is GPIOHANDLE_REQUEST_OUTPUT. > + * consumer_label: the name of consumer, such as "sysfs", "powerkey". > + * > + * Return value: On success return the fd of specific gpiochip. It could be > + * release by gpio_release. > + * On failure return the errno. > + */ > +int gpio_request(const char *device_name, unsigned int *lines, > + unsigned int nlines, unsigned int flag, > + struct gpiohandle_data *data, const char *consumer_label); For all of those, convert to kerneldoc (Documentation/kernel-doc-nano-HOWTO) and move the kerneldoc above the actual implementation, keep the header file spartan. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Aug 31, 2016 at 11:45:44AM +0200, bamvor.zhangjian@linaro.org wrote: > From: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> > > Add basic gpio operations. User could get/set gpio value and/or flag for > specific gpio chardev. > > Reference the "tools/testing/selftest/gpio/gpio-mockup-chardev.c" for > how to use it. > > Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> > --- > tools/gpio/gpio-utils.c | 163 ++++++++++++++++++++++++++++++++++++++++++++++++ > tools/gpio/gpio-utils.h | 121 +++++++++++++++++++++++++++++++++++ > 2 files changed, 284 insertions(+) > > diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c > index 8208718..3c0a35c 100644 > --- a/tools/gpio/gpio-utils.c > +++ b/tools/gpio/gpio-utils.c > @@ -2,10 +2,173 @@ > * 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" > + > +int gpio_request(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); > + goto exit_close_error; > + } > + > +exit_close_error: > + if (close(fd) == -1) > + perror("Failed to close GPIO character device file"); > + free(chrdev_name); > + return ret < 0 ? ret : req.fd; > +} > + > +int gpio_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); > + goto exit_close_error; This goto is unnecessary because there is no code to be skipped. > + } > + > +exit_close_error: > + return ret; > +} > + > +int gpio_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); > + goto exit_close_error; Same here. > + } > + > +exit_close_error: > + return ret; > +} > + > +int gpio_release(const int fd) > +{ > + int ret; > + > + ret = close(fd); > + if (ret < -1) > + perror("Failed to close GPIO LINEHANDLE device file"); > + > + return ret; > +} > + > +int gpio_gets(const char *device_name, unsigned int *lines, unsigned int nlines, > + unsigned int flag, struct gpiohandle_data *data) > +{ > + int fd; > + int ret; > + > + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); > + if (ret < 0) > + return ret; > + > + fd = ret; > + ret = gpio_get_values(fd, data); The error checking is missing here. > + ret = gpio_release(fd); Shouldn't we leave it up the user how they want the deal with the file handle? There is more system call overhead if we open and close the GPIO device for each access. > + return ret; > +} > + > +int gpio_sets(const char *device_name, unsigned int *lines, unsigned int nlines, > + unsigned int flag, struct gpiohandle_data *data) > +{ > + int ret; > + > + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); > + if (ret < 0) > + return ret; > + > + ret = gpio_release(ret); > + return ret; > +} > + > +int gpio_get(const char *device_name, unsigned int line, unsigned int flag) > +{ > + struct gpiohandle_data data; > + unsigned int lines[] = {line}; Is the lines variable really needed? > + > + gpio_gets(device_name, lines, 1, flag, &data); > + return data.values[0]; > +} > + > +int gpio_set(const char *device_name, unsigned int line, unsigned int flag, > + unsigned int value) > +{ > + struct gpiohandle_data data; > + unsigned int lines[] = {line}; > + > + data.values[0] = value; > + return gpio_sets(device_name, lines, 1, flag, &data); > +} > + > +int gpio_set_flag(const char *device_name, unsigned int line, unsigned int flag) > +{ > + struct gpiohandle_data data; > + unsigned int lines[] = {line}; > + int ret; > + > + ret = gpio_request(device_name, lines, 1, flag, &data, COMSUMER); > + if (ret < 0) > + return ret; > + > + ret = gpio_release(ret); > + return ret; > +} > + > diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h > index 5f57133..fcf87b6 100644 > --- a/tools/gpio/gpio-utils.h > +++ b/tools/gpio/gpio-utils.h > @@ -24,4 +24,125 @@ static inline int check_prefix(const char *str, const char *prefix) > strncmp(str, prefix, strlen(prefix)) == 0; > } > > +/* Basic operation of gpio */ > +/* > + * Request the lines for gpio with device_name. Could set the default value > + * in request. > + * device_name: the name of gpiochip in "/dev", such as gpiochip0. > + * lines: the array of which line should be requested. > + * nline: the total number of line > + * flag: input, output and so on. Reference "linux/gpio.h" for the > + * meaning for flag. > + * data: default value when flag is GPIOHANDLE_REQUEST_OUTPUT. > + * consumer_label: the name of consumer, such as "sysfs", "powerkey". > + * > + * Return value: On success return the fd of specific gpiochip. It could be > + * release by gpio_release. > + * On failure return the errno. > + */ > +int gpio_request(const char *device_name, unsigned int *lines, > + unsigned int nlines, unsigned int flag, > + struct gpiohandle_data *data, const char *consumer_label); > +/* > + * Set the value of gpio for fd > + * fd: the fd returned by gpio_request > + * data: the value want to set > + * > + * Return value: On success return 0 > + * On failure return the errno. > + */ > +int gpio_set_values(const int fd, struct gpiohandle_data *data); > + > +/* > + * Get the value of gpio for fd > + * fd: the fd returned by gpio_request > + * data: the valud get from gpiochip. > + * > + * Return value: On success return 0 > + * On failure return the errno. > + */ > +int gpio_get_values(const int fd, struct gpiohandle_data *data); > + > +/* > + * release the fd for gpiochip > + */ > +int gpio_release(const int fd); > + > +/* Easy operation for one time get/set */ > +/* > + * Get one pin value from line of device_name. Could change the flag if > + * necessary. > + * device_name: the name of gpiochip in "/dev", such as gpiochip0. > + * line: number of line, such as 2. > + * flag: input, output and so on. Reference "linux/gpio.h" for the > + * meaning for flag. Set to 0 if do not want to update the > + * flag. It is the recommandation value. > + * > + * Return value: On success return the value get from gpiochip. > + * On failure return the errno. > + */ > +int gpio_get(const char *device_name, unsigned int line, unsigned int flag); > + > +/* > + * Get pins value from line of device_name. Could change the flag if > + * necessary. > + * device_name: the name of gpiochip in "/dev", such as gpiochip0. > + * lines: the array of which line should be requested. > + * nline: the total number of line > + * flag: input, output and so on. Reference "linux/gpio.h" for the > + * meaning for flag. > + * data: the valud get from gpiochip. > + * > + * Return value: On success return 0 > + * On failure return the errno. > + */ > +int gpio_gets(const char *device_name, unsigned int *lines, unsigned int nlines, > + unsigned int flag, struct gpiohandle_data *data); > + > +/* > + * Set one pin value from line of device_name. Could change the flag if > + * necessary. > + * device_name: the name of gpiochip in "/dev", such as gpiochip0. > + * line: number of line, such as 2. > + * flag: input, output and so on. Reference "linux/gpio.h" for the > + * meaning for flag. Set to 0 if do not want to update the > + * flag. It is the recommandation value. > + * value: the value want to set the gpio line. > + * > + * Return value: On success return 0 > + * On failure return the errno. > + */ > +int gpio_set(const char *device_name, unsigned int line, unsigned int flag, > + unsigned int value); > + > +/* > + * Set pins value from line of device_name. Could change the flag if > + * necessary. > + * device_name: the name of gpiochip in "/dev", such as gpiochip0. > + * lines: the array of which line should be requested. > + * nline: the total number of line > + * flag: input, output and so on. Reference "linux/gpio.h" for the > + * meaning for flag. > + * data: the value want to set > + * > + * Return value: On success return 0 > + * On failure return the errno. > + */ > +int gpio_sets(const char *device_name, unsigned int *lines, unsigned int nlines, > + unsigned int flag, struct gpiohandle_data *data); > + > +/* > + * set the flag for device_name. Mainly for changing the direction of gpio > + * > + * device_name: the name of gpiochip in "/dev", such as gpiochip0. > + * line: number of line, such as 2. > + * flag: input, output and so on. Reference "linux/gpio.h" for the > + * meaning for flag. > + * > + * Return value: On success return 0 > + * On failure return the errno. > + */ > +int gpio_set_flag(const char *device_name, unsigned int line, > + unsigned int flag); > + > #endif /* _GPIO_UTILS_H_ */ > -- > 1.8.4.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-gpio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, Michael On 28 September 2016 at 12:16, Michael Welling <mwelling@ieee.org> wrote: > On Wed, Aug 31, 2016 at 11:45:44AM +0200, bamvor.zhangjian@linaro.org wrote: >> From: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> [...] >> + 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); >> + goto exit_close_error; > > This goto is unnecessary because there is no code to be skipped. > >> + } >> + >> +exit_close_error: >> + return ret; >> +} >> + >> +int gpio_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); >> + goto exit_close_error; > > Same here. Thanks. I will fix above two in next version. > >> + } >> + >> +exit_close_error: >> + return ret; >> +} >> + >> +int gpio_release(const int fd) >> +{ >> + int ret; >> + >> + ret = close(fd); >> + if (ret < -1) >> + perror("Failed to close GPIO LINEHANDLE device file"); >> + >> + return ret; >> +} >> + >> +int gpio_gets(const char *device_name, unsigned int *lines, unsigned int nlines, >> + unsigned int flag, struct gpiohandle_data *data) >> +{ >> + int fd; >> + int ret; >> + >> + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); >> + if (ret < 0) >> + return ret; >> + >> + fd = ret; >> + ret = gpio_get_values(fd, data); > > The error checking is missing here. Well, no matter the gpio_get_values fails or not. We both need to release the line we request. But, we need the return value if gpio_get_values fails. In the next version, I will return the errno of gpio_get_values if it fails. > >> + ret = gpio_release(fd); > > Shouldn't we leave it up the user how they want the deal with the file handle? > There is more system call overhead if we open and close the GPIO device for > each access. Yes. I understand and agree the syscall overhead you mentioned. So, I provide the request, ops, release ops above. These gpio_[sg]ets? functions is the easy way if the user only access the gpio in a few times. > >> + return ret; >> +} >> + >> +int gpio_sets(const char *device_name, unsigned int *lines, unsigned int nlines, >> + unsigned int flag, struct gpiohandle_data *data) >> +{ >> + int ret; >> + >> + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); >> + if (ret < 0) >> + return ret; >> + >> + ret = gpio_release(ret); >> + return ret; >> +} >> + >> +int gpio_get(const char *device_name, unsigned int line, unsigned int flag) >> +{ >> + struct gpiohandle_data data; >> + unsigned int lines[] = {line}; > > Is the lines variable really needed? Do you mean something like gpio_gets(device_name, {line}, 1, flag, &data);? Personally, I like the first version. Because it is more clear and compiler will optimize it anyway. Ideas? Regards Bamvor -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Sep 28, 2016 at 02:35:17PM -0700, Bamvor Zhang Jian wrote: > Hi, Michael > > On 28 September 2016 at 12:16, Michael Welling <mwelling@ieee.org> wrote: > > On Wed, Aug 31, 2016 at 11:45:44AM +0200, bamvor.zhangjian@linaro.org wrote: > >> From: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> > [...] > >> + 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); > >> + goto exit_close_error; > > > > This goto is unnecessary because there is no code to be skipped. > > > >> + } > >> + > >> +exit_close_error: > >> + return ret; > >> +} > >> + > >> +int gpio_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); > >> + goto exit_close_error; > > > > Same here. > Thanks. I will fix above two in next version. > > > >> + } > >> + > >> +exit_close_error: > >> + return ret; > >> +} > >> + > >> +int gpio_release(const int fd) > >> +{ > >> + int ret; > >> + > >> + ret = close(fd); > >> + if (ret < -1) > >> + perror("Failed to close GPIO LINEHANDLE device file"); > >> + > >> + return ret; > >> +} > >> + > >> +int gpio_gets(const char *device_name, unsigned int *lines, unsigned int nlines, > >> + unsigned int flag, struct gpiohandle_data *data) > >> +{ > >> + int fd; > >> + int ret; > >> + > >> + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); > >> + if (ret < 0) > >> + return ret; > >> + > >> + fd = ret; > >> + ret = gpio_get_values(fd, data); > > > > The error checking is missing here. > Well, no matter the gpio_get_values fails or not. We both need to release the > line we request. But, we need the return value if gpio_get_values fails. In the > next version, I will return the errno of gpio_get_values if it fails. > > > >> + ret = gpio_release(fd); > > > > Shouldn't we leave it up the user how they want the deal with the file handle? > > There is more system call overhead if we open and close the GPIO device for > > each access. > Yes. I understand and agree the syscall overhead you mentioned. So, I provide > the request, ops, release ops above. These gpio_[sg]ets? functions is the easy > way if the user only access the gpio in a few times. > > > >> + return ret; > >> +} > >> + > >> +int gpio_sets(const char *device_name, unsigned int *lines, unsigned int nlines, > >> + unsigned int flag, struct gpiohandle_data *data) > >> +{ > >> + int ret; > >> + > >> + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); > >> + if (ret < 0) > >> + return ret; > >> + > >> + ret = gpio_release(ret); > >> + return ret; > >> +} > >> + > >> +int gpio_get(const char *device_name, unsigned int line, unsigned int flag) > >> +{ > >> + struct gpiohandle_data data; > >> + unsigned int lines[] = {line}; > > > > Is the lines variable really needed? > Do you mean something like gpio_gets(device_name, {line}, 1, flag, &data);? > Personally, I like the first version. Because it is more clear and compiler > will optimize it anyway. Ideas? gpio_gets(device_name, &line, 1, flag, &data); It may be easier to understand the way you have it. > > Regards > > Bamvor -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c index 8208718..3c0a35c 100644 --- a/tools/gpio/gpio-utils.c +++ b/tools/gpio/gpio-utils.c @@ -2,10 +2,173 @@ * 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" + +int gpio_request(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); + goto exit_close_error; + } + +exit_close_error: + if (close(fd) == -1) + perror("Failed to close GPIO character device file"); + free(chrdev_name); + return ret < 0 ? ret : req.fd; +} + +int gpio_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); + goto exit_close_error; + } + +exit_close_error: + return ret; +} + +int gpio_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); + goto exit_close_error; + } + +exit_close_error: + return ret; +} + +int gpio_release(const int fd) +{ + int ret; + + ret = close(fd); + if (ret < -1) + perror("Failed to close GPIO LINEHANDLE device file"); + + return ret; +} + +int gpio_gets(const char *device_name, unsigned int *lines, unsigned int nlines, + unsigned int flag, struct gpiohandle_data *data) +{ + int fd; + int ret; + + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); + if (ret < 0) + return ret; + + fd = ret; + ret = gpio_get_values(fd, data); + ret = gpio_release(fd); + return ret; +} + +int gpio_sets(const char *device_name, unsigned int *lines, unsigned int nlines, + unsigned int flag, struct gpiohandle_data *data) +{ + int ret; + + ret = gpio_request(device_name, lines, nlines, flag, data, COMSUMER); + if (ret < 0) + return ret; + + ret = gpio_release(ret); + return ret; +} + +int gpio_get(const char *device_name, unsigned int line, unsigned int flag) +{ + struct gpiohandle_data data; + unsigned int lines[] = {line}; + + gpio_gets(device_name, lines, 1, flag, &data); + return data.values[0]; +} + +int gpio_set(const char *device_name, unsigned int line, unsigned int flag, + unsigned int value) +{ + struct gpiohandle_data data; + unsigned int lines[] = {line}; + + data.values[0] = value; + return gpio_sets(device_name, lines, 1, flag, &data); +} + +int gpio_set_flag(const char *device_name, unsigned int line, unsigned int flag) +{ + struct gpiohandle_data data; + unsigned int lines[] = {line}; + int ret; + + ret = gpio_request(device_name, lines, 1, flag, &data, COMSUMER); + if (ret < 0) + return ret; + + ret = gpio_release(ret); + return ret; +} + diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h index 5f57133..fcf87b6 100644 --- a/tools/gpio/gpio-utils.h +++ b/tools/gpio/gpio-utils.h @@ -24,4 +24,125 @@ static inline int check_prefix(const char *str, const char *prefix) strncmp(str, prefix, strlen(prefix)) == 0; } +/* Basic operation of gpio */ +/* + * Request the lines for gpio with device_name. Could set the default value + * in request. + * device_name: the name of gpiochip in "/dev", such as gpiochip0. + * lines: the array of which line should be requested. + * nline: the total number of line + * flag: input, output and so on. Reference "linux/gpio.h" for the + * meaning for flag. + * data: default value when flag is GPIOHANDLE_REQUEST_OUTPUT. + * consumer_label: the name of consumer, such as "sysfs", "powerkey". + * + * Return value: On success return the fd of specific gpiochip. It could be + * release by gpio_release. + * On failure return the errno. + */ +int gpio_request(const char *device_name, unsigned int *lines, + unsigned int nlines, unsigned int flag, + struct gpiohandle_data *data, const char *consumer_label); +/* + * Set the value of gpio for fd + * fd: the fd returned by gpio_request + * data: the value want to set + * + * Return value: On success return 0 + * On failure return the errno. + */ +int gpio_set_values(const int fd, struct gpiohandle_data *data); + +/* + * Get the value of gpio for fd + * fd: the fd returned by gpio_request + * data: the valud get from gpiochip. + * + * Return value: On success return 0 + * On failure return the errno. + */ +int gpio_get_values(const int fd, struct gpiohandle_data *data); + +/* + * release the fd for gpiochip + */ +int gpio_release(const int fd); + +/* Easy operation for one time get/set */ +/* + * Get one pin value from line of device_name. Could change the flag if + * necessary. + * device_name: the name of gpiochip in "/dev", such as gpiochip0. + * line: number of line, such as 2. + * flag: input, output and so on. Reference "linux/gpio.h" for the + * meaning for flag. Set to 0 if do not want to update the + * flag. It is the recommandation value. + * + * Return value: On success return the value get from gpiochip. + * On failure return the errno. + */ +int gpio_get(const char *device_name, unsigned int line, unsigned int flag); + +/* + * Get pins value from line of device_name. Could change the flag if + * necessary. + * device_name: the name of gpiochip in "/dev", such as gpiochip0. + * lines: the array of which line should be requested. + * nline: the total number of line + * flag: input, output and so on. Reference "linux/gpio.h" for the + * meaning for flag. + * data: the valud get from gpiochip. + * + * Return value: On success return 0 + * On failure return the errno. + */ +int gpio_gets(const char *device_name, unsigned int *lines, unsigned int nlines, + unsigned int flag, struct gpiohandle_data *data); + +/* + * Set one pin value from line of device_name. Could change the flag if + * necessary. + * device_name: the name of gpiochip in "/dev", such as gpiochip0. + * line: number of line, such as 2. + * flag: input, output and so on. Reference "linux/gpio.h" for the + * meaning for flag. Set to 0 if do not want to update the + * flag. It is the recommandation value. + * value: the value want to set the gpio line. + * + * Return value: On success return 0 + * On failure return the errno. + */ +int gpio_set(const char *device_name, unsigned int line, unsigned int flag, + unsigned int value); + +/* + * Set pins value from line of device_name. Could change the flag if + * necessary. + * device_name: the name of gpiochip in "/dev", such as gpiochip0. + * lines: the array of which line should be requested. + * nline: the total number of line + * flag: input, output and so on. Reference "linux/gpio.h" for the + * meaning for flag. + * data: the value want to set + * + * Return value: On success return 0 + * On failure return the errno. + */ +int gpio_sets(const char *device_name, unsigned int *lines, unsigned int nlines, + unsigned int flag, struct gpiohandle_data *data); + +/* + * set the flag for device_name. Mainly for changing the direction of gpio + * + * device_name: the name of gpiochip in "/dev", such as gpiochip0. + * line: number of line, such as 2. + * flag: input, output and so on. Reference "linux/gpio.h" for the + * meaning for flag. + * + * Return value: On success return 0 + * On failure return the errno. + */ +int gpio_set_flag(const char *device_name, unsigned int line, + unsigned int flag); + #endif /* _GPIO_UTILS_H_ */