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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-pink 1.4.1 (git 2.36.1) at 2024-10-08 21:28:06 +0000