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From:   Kent Gibson <warthog618@gmail.com>
To:     linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
        bgolaszewski@baylibre.com, linus.walleij@linaro.org,
        andy.shevchenko@gmail.com
Cc:     arnd@arndb.de, Kent Gibson <warthog618@gmail.com>
Subject: [PATCH v9 03/20] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes
Date:   Tue, 22 Sep 2020 10:31:34 +0800
Message-Id: <20200922023151.387447-4-warthog618@gmail.com>
In-Reply-To: <20200922023151.387447-1-warthog618@gmail.com>
References: <20200922023151.387447-1-warthog618@gmail.com>
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Replace constant array sizes with a macro constant to clarify the source
of array sizes, provide a place to document any constraints on the size,
and to simplify array sizing in userspace if constructing structs
from their composite fields.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
 include/uapi/linux/gpio.h | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index 9c27cecf406f..285cc10355b2 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -14,6 +14,11 @@
 #include <linux/ioctl.h>
 #include <linux/types.h>
 
+/*
+ * The maximum size of name and label arrays.
+ */
+#define GPIO_MAX_NAME_SIZE 32
+
 /**
  * struct gpiochip_info - Information about a certain GPIO chip
  * @name: the Linux kernel name of this GPIO chip
@@ -22,8 +27,8 @@
  * @lines: number of GPIO lines on this chip
  */
 struct gpiochip_info {
-	char name[32];
-	char label[32];
+	char name[GPIO_MAX_NAME_SIZE];
+	char label[GPIO_MAX_NAME_SIZE];
 	__u32 lines;
 };
 
@@ -52,8 +57,8 @@ struct gpiochip_info {
 struct gpioline_info {
 	__u32 line_offset;
 	__u32 flags;
-	char name[32];
-	char consumer[32];
+	char name[GPIO_MAX_NAME_SIZE];
+	char consumer[GPIO_MAX_NAME_SIZE];
 };
 
 /* Maximum number of requested handles */
@@ -123,7 +128,7 @@ struct gpiohandle_request {
 	__u32 lineoffsets[GPIOHANDLES_MAX];
 	__u32 flags;
 	__u8 default_values[GPIOHANDLES_MAX];
-	char consumer_label[32];
+	char consumer_label[GPIO_MAX_NAME_SIZE];
 	__u32 lines;
 	int fd;
 };
@@ -182,7 +187,7 @@ struct gpioevent_request {
 	__u32 lineoffset;
 	__u32 handleflags;
 	__u32 eventflags;
-	char consumer_label[32];
+	char consumer_label[GPIO_MAX_NAME_SIZE];
 	int fd;
 };
 
-- 
2.28.0