gpio: mockup: use simple_read_from_buffer() in debugfs read callback

Calling read() for a single byte read will return 2 currently. Use
simple_read_from_buffer() which correctly handles all sizes.

Fixes: 2a9e27408e12 ("gpio: mockup: rework debugfs interface")
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 74ba8b1d71d8..b6a4efce7c92 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -204,10 +204,9 @@ static ssize_t gpio_mockup_debugfs_read(struct file *file,
         struct gpio_mockup_chip *chip;
         struct seq_file *sfile;
         struct gpio_chip *gc;
-        int val, rv, cnt;
+        int val, cnt;
         char buf[3];
 
-
         if (*ppos != 0)
                 return 0;
 
@@ -219,12 +218,7 @@ static ssize_t gpio_mockup_debugfs_read(struct file *file,
         val = gpio_mockup_get(gc, priv->offset);
         cnt = snprintf(buf, sizeof(buf), "%d\n", val);
 
-        rv = copy_to_user(usr_buf, buf, cnt);
-        if (rv)
-                return rv;
-
-        *ppos += cnt;
-        return cnt;
+        return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt);
 }
 
 static ssize_t gpio_mockup_debugfs_write(struct file *file,