From: Bartosz Golaszewski <bartekgola@gmail.com>
Date: Mon, 2 Jan 2017 15:05:59 +0000 (+0100)
Subject: core: add libgpiod-specific error numbers
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=db64f467fb7a984d2ff9c17a3bcfb4ac8cd63600;p=qemu-gpiodev%2Flibgpiod.git

core: add libgpiod-specific error numbers

In order to better report error conditions to users, we need a set
of libgpiod-specific errnos. Extend the previous API to be able to
use both regular errno and GPIO-related error numbers together.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
---

diff --git a/core.c b/core.c
index d777f5c..a108eda 100644
--- a/core.c
+++ b/core.c
@@ -27,6 +27,11 @@ static const char libgpiod_consumer[] = "libgpiod";
 
 static __thread int last_error;
 
+static const char *const error_descr[] = {
+	"success",
+	"GPIO line not requested",
+};
+
 static void set_last_error(int errnum)
 {
 	last_error = errnum;
@@ -79,7 +84,12 @@ int gpiod_errno(void)
 
 const char * gpiod_strerror(int errnum)
 {
-	return strerror(errnum);
+	if (errnum < __GPIOD_ERRNO_OFFSET)
+		return strerror(errnum);
+	else if (errnum > __GPIOD_MAX_ERR)
+		return "invalid error number";
+	else
+		return error_descr[errnum - __GPIOD_ERRNO_OFFSET];
 }
 
 int gpiod_simple_get_value(const char *device, unsigned int offset)
@@ -254,7 +264,7 @@ int gpiod_line_get_value(struct gpiod_line *line)
 	int status;
 
 	if (!gpiod_line_is_requested(line)) {
-		set_last_error(EPERM);
+		set_last_error(GPIOD_ENOTREQUESTED);
 		return -1;
 	}
 
@@ -274,7 +284,7 @@ int gpiod_line_set_value(struct gpiod_line *line, int value)
 	int status;
 
 	if (!gpiod_line_is_requested(line)) {
-		set_last_error(EPERM);
+		set_last_error(GPIOD_ENOTREQUESTED);
 		return -1;
 	}
 
diff --git a/gpiod.h b/gpiod.h
index fa9215a..a433374 100644
--- a/gpiod.h
+++ b/gpiod.h
@@ -32,6 +32,14 @@ extern "C" {
 
 #define GPIOD_BIT(nr)		(1UL << (nr))
 
+#define __GPIOD_ERRNO_OFFSET	10000
+
+enum {
+	GPIOD_ESUCCESS = __GPIOD_ERRNO_OFFSET,
+	GPIOD_ENOTREQUESTED,
+	__GPIOD_MAX_ERR,
+};
+
 int gpiod_errno(void) GPIOD_API;
 
 const char * gpiod_strerror(int errnum) GPIOD_API;