mfd: htc-i2cpld: Rectify pointer offset error

Checking the result of container_of() against NULL will always result to
false.  Using the offset of member 'chip_out' to find the start of 'struct
htcpld_chip' will result in an offset error when .get_chip() is attempting
to obtain 'htcpld-in'.  Instead, we'll use the correct member based on a
previously the set chip label.

Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/mfd/htc-i2cpld.c b/drivers/mfd/htc-i2cpld.c
index 073e1801cdab20380d457feed3b3713a4fddc9c0..99b362e4332985697d80bdd366b5175915d49cd6 100644 (file)
--- a/drivers/mfd/htc-i2cpld.c
+++ b/drivers/mfd/htc-i2cpld.c
@@ -258,31 +258,18 @@ static void htcpld_chip_set_ni(struct work_struct *work)
 static int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
 {
        struct htcpld_chip *chip_data;
-       int val = 0;
-       int is_input = 0;
-
-       /* Try out first */
-       chip_data = container_of(chip, struct htcpld_chip, chip_out);
-       if (!chip_data) {
-               /* Try in */
-               is_input = 1;
-               chip_data = container_of(chip, struct htcpld_chip, chip_in);
-               if (!chip_data)
-                       return -EINVAL;
-       }
+       u8 cache;
 
-       /* Determine if this is an input or output GPIO */
-       if (!is_input)
-               /* Use the output cache */
-               val = (chip_data->cache_out >> offset) & 1;
-       else
-               /* Use the input cache */
-               val = (chip_data->cache_in >> offset) & 1;
+       if (!strncmp(chip->label, "htcpld-out", 10)) {
+               chip_data = container_of(chip, struct htcpld_chip, chip_out);
+               cache = chip_data->cache_out;
+       } else if (!strncmp(chip->label, "htcpld-in", 9)) {
+               chip_data = container_of(chip, struct htcpld_chip, chip_in);
+               cache = chip_data->cache_in;
+       } else
+               return -EINVAL;
 
-       if (val)
-               return 1;
-       else
-               return 0;
+       return (cache >> offset) & 1;
 }
 
 static int htcpld_direction_output(struct gpio_chip *chip,