diff options
-rw-r--r-- | drivers/gpio/gpio-lp3943.c | 22 | ||||
-rw-r--r-- | include/linux/mfd/lp3943.h | 6 |
2 files changed, 28 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-lp3943.c b/drivers/gpio/gpio-lp3943.c index fdec94b..6dc6725 100644 --- a/drivers/gpio/gpio-lp3943.c +++ b/drivers/gpio/gpio-lp3943.c @@ -45,6 +45,26 @@ 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) { @@ -157,6 +177,8 @@ 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, diff --git a/include/linux/mfd/lp3943.h b/include/linux/mfd/lp3943.h index d3a73811..3490db7 100644 --- a/include/linux/mfd/lp3943.h +++ b/include/linux/mfd/lp3943.h @@ -94,12 +94,18 @@ 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); |