gpio: cs5535: use gpiochip data pointer

This makes the driver use the data pointer added to the gpio_chip
to store a pointer to the state container instead of relying on
container_of().

Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-cs5535.c b/drivers/gpio/gpio-cs5535.c
index 7b0b198..eccb712 100644
--- a/drivers/gpio/gpio-cs5535.c
+++ b/drivers/gpio/gpio-cs5535.c
@@ -42,6 +42,10 @@
 module_param_named(mask, mask, ulong, 0444);
 MODULE_PARM_DESC(mask, "GPIO channel mask.");
 
+/*
+ * FIXME: convert this singleton driver to use the state container
+ * design pattern, see Documentation/driver-model/design-patterns.txt
+ */
 static struct cs5535_gpio_chip {
 	struct gpio_chip chip;
 	resource_size_t base;
@@ -201,8 +205,7 @@
 
 static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
 {
-	struct cs5535_gpio_chip *chip =
-		container_of(c, struct cs5535_gpio_chip, chip);
+	struct cs5535_gpio_chip *chip = gpiochip_get_data(c);
 	unsigned long flags;
 
 	spin_lock_irqsave(&chip->lock, flags);
@@ -242,8 +245,7 @@
 
 static int chip_direction_input(struct gpio_chip *c, unsigned offset)
 {
-	struct cs5535_gpio_chip *chip =
-		container_of(c, struct cs5535_gpio_chip, chip);
+	struct cs5535_gpio_chip *chip = gpiochip_get_data(c);
 	unsigned long flags;
 
 	spin_lock_irqsave(&chip->lock, flags);
@@ -256,8 +258,7 @@
 
 static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
 {
-	struct cs5535_gpio_chip *chip =
-		container_of(c, struct cs5535_gpio_chip, chip);
+	struct cs5535_gpio_chip *chip = gpiochip_get_data(c);
 	unsigned long flags;
 
 	spin_lock_irqsave(&chip->lock, flags);
@@ -347,7 +348,7 @@
 				mask_orig, mask);
 
 	/* finally, register with the generic GPIO API */
-	err = gpiochip_add(&cs5535_gpio_chip.chip);
+	err = gpiochip_add_data(&cs5535_gpio_chip.chip, &cs5535_gpio_chip);
 	if (err)
 		goto done;