gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free

The implementation of lp3943_gpio_request/lp3943_gpio_free test pin_used
for tracing the pin usage. However, gpiolib already checks FLAG_REQUESTED
flag for the same purpose. So remove the redundant implementation.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-lp3943.c

@@ -45,26 +45,6 @@ struct lp3943_gpio {
 	u16 input_mask;		/* 1 = GPIO is input direction, 0 = output */
 };
 
-static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)
-{
-	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
-	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
-
-	/* Return an error if the pin is already assigned */
-	if (test_and_set_bit(offset, &lp3943->pin_used))
-		return -EBUSY;
-
-	return 0;
-}
-
-static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset)
-{
-	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
-	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
-
-	clear_bit(offset, &lp3943->pin_used);
-}
-
 static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset,
 				u8 val)
 {
@@ -177,8 +157,6 @@ static int lp3943_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 static const struct gpio_chip lp3943_gpio_chip = {
 	.label			= "lp3943",
 	.owner			= THIS_MODULE,
-	.request		= lp3943_gpio_request,
-	.free			= lp3943_gpio_free,
 	.direction_input	= lp3943_gpio_direction_input,
 	.get			= lp3943_gpio_get,
 	.direction_output	= lp3943_gpio_direction_output,

include/linux/mfd/lp3943.h

@@ -94,18 +94,12 @@ struct lp3943_reg_cfg {
  * @regmap: Used for I2C communication on accessing registers
  * @pdata: LP3943 platform specific data
  * @mux_cfg: Register configuration for pin MUX
- * @pin_used: Bit mask for output pin used.
- *	      This bitmask is used for pin assignment management.
- *	      1 = pin used, 0 = available.
- *	      Only LSB 16 bits are used, but it is unsigned long type
- *	      for atomic bitwise operations.
  */
 struct lp3943 {
 	struct device *dev;
 	struct regmap *regmap;
 	struct lp3943_platform_data *pdata;
 	const struct lp3943_reg_cfg *mux_cfg;
-	unsigned long pin_used;
 };
 
 int lp3943_read_byte(struct lp3943 *lp3943, u8 reg, u8 *read);