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-rw-r--r--drivers/gpio/gpiolib.c51
-rw-r--r--include/uapi/linux/gpio.h26
-rw-r--r--tools/gpio/gpio-utils.h2
-rw-r--r--tools/gpio/lsgpio.c91
4 files changed, 156 insertions, 14 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 797c790aa750..3580c0de9d5a 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -331,14 +331,15 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
struct gpio_device *gdev = filp->private_data;
struct gpio_chip *chip = gdev->chip;
int __user *ip = (int __user *)arg;
- struct gpiochip_info chipinfo;
/* We fail any subsequent ioctl():s when the chip is gone */
if (!chip)
return -ENODEV;
+ /* Fill in the struct and pass to userspace */
if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
- /* Fill in the struct and pass to userspace */
+ struct gpiochip_info chipinfo;
+
strncpy(chipinfo.name, dev_name(&gdev->dev),
sizeof(chipinfo.name));
chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
@@ -349,6 +350,52 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
return -EFAULT;
return 0;
+ } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
+ struct gpioline_info lineinfo;
+ struct gpio_desc *desc;
+
+ if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
+ return -EFAULT;
+ if (lineinfo.line_offset > gdev->ngpio)
+ return -EINVAL;
+
+ desc = &gdev->descs[lineinfo.line_offset];
+ if (desc->name) {
+ strncpy(lineinfo.name, desc->name,
+ sizeof(lineinfo.name));
+ lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
+ } else {
+ lineinfo.name[0] = '\0';
+ }
+ if (desc->label) {
+ strncpy(lineinfo.label, desc->label,
+ sizeof(lineinfo.label));
+ lineinfo.label[sizeof(lineinfo.label)-1] = '\0';
+ } else {
+ lineinfo.label[0] = '\0';
+ }
+
+ /*
+ * Userspace only need to know that the kernel is using
+ * this GPIO so it can't use it.
+ */
+ lineinfo.flags = 0;
+ if (desc->flags & (FLAG_REQUESTED | FLAG_IS_HOGGED |
+ FLAG_USED_AS_IRQ | FLAG_EXPORT |
+ FLAG_SYSFS))
+ lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
+ if (desc->flags & FLAG_IS_OUT)
+ lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
+ if (desc->flags & FLAG_ACTIVE_LOW)
+ lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
+ if (desc->flags & FLAG_OPEN_DRAIN)
+ lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
+ if (desc->flags & FLAG_OPEN_SOURCE)
+ lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
+
+ if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
+ return -EFAULT;
+ return 0;
}
return -EINVAL;
}
diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index 3f93e1bcd3dd..416ce47f2291 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -25,6 +25,32 @@ struct gpiochip_info {
__u32 lines;
};
+/* Line is in use by the kernel */
+#define GPIOLINE_FLAG_KERNEL (1UL << 0)
+#define GPIOLINE_FLAG_IS_OUT (1UL << 1)
+#define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2)
+#define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3)
+#define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4)
+
+/**
+ * struct gpioline_info - Information about a certain GPIO line
+ * @line_offset: the local offset on this GPIO device, fill in when
+ * requesting information from the kernel
+ * @flags: various flags for this line
+ * @name: the name of this GPIO line
+ * @label: a functional name for this GPIO line
+ * @kernel: this GPIO is in use by the kernel
+ * @out: this GPIO is an output line (false means it is an input)
+ * @active_low: this GPIO is active low
+ */
+struct gpioline_info {
+ __u32 line_offset;
+ __u32 flags;
+ char name[32];
+ char label[32];
+};
+
#define GPIO_GET_CHIPINFO_IOCTL _IOR('o', 0x01, struct gpiochip_info)
+#define GPIO_GET_LINEINFO_IOCTL _IOWR('o', 0x02, struct gpioline_info)
#endif /* _UAPI_GPIO_H_ */
diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h
index b18209a45ad3..5f57133b8c04 100644
--- a/tools/gpio/gpio-utils.h
+++ b/tools/gpio/gpio-utils.h
@@ -16,6 +16,8 @@
#include <string.h>
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
static inline int check_prefix(const char *str, const char *prefix)
{
return strlen(str) > strlen(prefix) &&
diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c
index 692233f561fb..5535ce81f8f7 100644
--- a/tools/gpio/lsgpio.c
+++ b/tools/gpio/lsgpio.c
@@ -26,12 +26,56 @@
#include "gpio-utils.h"
+struct gpio_flag {
+ char *name;
+ unsigned long mask;
+};
+
+struct gpio_flag flagnames[] = {
+ {
+ .name = "kernel",
+ .mask = GPIOLINE_FLAG_KERNEL,
+ },
+ {
+ .name = "output",
+ .mask = GPIOLINE_FLAG_IS_OUT,
+ },
+ {
+ .name = "active-low",
+ .mask = GPIOLINE_FLAG_ACTIVE_LOW,
+ },
+ {
+ .name = "open-drain",
+ .mask = GPIOLINE_FLAG_OPEN_DRAIN,
+ },
+ {
+ .name = "open-source",
+ .mask = GPIOLINE_FLAG_OPEN_SOURCE,
+ },
+};
+
+void print_flags(unsigned long flags)
+{
+ int i;
+ int printed = 0;
+
+ for (i = 0; i < ARRAY_SIZE(flagnames); i++) {
+ if (flags & flagnames[i].mask) {
+ if (printed)
+ fprintf(stdout, " ");
+ fprintf(stdout, "%s", flagnames[i].name);
+ printed++;
+ }
+ }
+}
+
int list_device(const char *device_name)
{
struct gpiochip_info cinfo;
char *chrdev_name;
int fd;
int ret;
+ int i;
ret = asprintf(&chrdev_name, "/dev/%s", device_name);
if (ret < 0)
@@ -41,32 +85,55 @@ int list_device(const char *device_name)
if (fd == -1) {
ret = -errno;
fprintf(stderr, "Failed to open %s\n", chrdev_name);
- goto free_chrdev_name;
+ goto exit_close_error;
}
/* Inspect this GPIO chip */
ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo);
if (ret == -1) {
ret = -errno;
- fprintf(stderr, "Failed to retrieve GPIO fd\n");
- if (close(fd) == -1)
- perror("Failed to close GPIO character device file");
-
- goto free_chrdev_name;
+ perror("Failed to issue CHIPINFO IOCTL\n");
+ goto exit_close_error;
}
fprintf(stdout, "GPIO chip: %s, \"%s\", %u GPIO lines\n",
cinfo.name, cinfo.label, cinfo.lines);
- if (close(fd) == -1) {
- ret = -errno;
- goto free_chrdev_name;
+ /* Loop over the lines and print info */
+ for (i = 0; i < cinfo.lines; i++) {
+ struct gpioline_info linfo;
+
+ memset(&linfo, 0, sizeof(linfo));
+ linfo.line_offset = i;
+
+ ret = ioctl(fd, GPIO_GET_LINEINFO_IOCTL, &linfo);
+ if (ret == -1) {
+ ret = -errno;
+ perror("Failed to issue LINEINFO IOCTL\n");
+ goto exit_close_error;
+ }
+ fprintf(stdout, "\tline %d:", linfo.line_offset);
+ if (linfo.name[0])
+ fprintf(stdout, " %s", linfo.name);
+ else
+ fprintf(stdout, " unnamed");
+ if (linfo.label[0])
+ fprintf(stdout, " \"%s\"", linfo.label);
+ else
+ fprintf(stdout, " unlabeled");
+ if (linfo.flags) {
+ fprintf(stdout, " [");
+ print_flags(linfo.flags);
+ fprintf(stdout, "]");
+ }
+ fprintf(stdout, "\n");
+
}
-free_chrdev_name:
+exit_close_error:
+ if (close(fd) == -1)
+ perror("Failed to close GPIO character device file");
free(chrdev_name);
-
return ret;
-
}
void print_usage(void)
generated by cgit (git 2.34.1) at 2024-06-07 08:46:52 +0000