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70aba44b6c
This reverts commit 3fab91ea28
.
230 lines
5.5 KiB
C
230 lines
5.5 KiB
C
/*
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* TI/National Semiconductor LP3943 GPIO driver
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*
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* Copyright 2013 Texas Instruments
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*
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* Author: Milo Kim <milo.kim@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2.
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*/
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#include <linux/bitops.h>
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/i2c.h>
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#include <linux/mfd/lp3943.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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enum lp3943_gpios {
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LP3943_GPIO1,
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LP3943_GPIO2,
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LP3943_GPIO3,
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LP3943_GPIO4,
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LP3943_GPIO5,
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LP3943_GPIO6,
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LP3943_GPIO7,
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LP3943_GPIO8,
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LP3943_GPIO9,
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LP3943_GPIO10,
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LP3943_GPIO11,
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LP3943_GPIO12,
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LP3943_GPIO13,
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LP3943_GPIO14,
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LP3943_GPIO15,
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LP3943_GPIO16,
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LP3943_MAX_GPIO,
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};
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struct lp3943_gpio {
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struct gpio_chip chip;
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struct lp3943 *lp3943;
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u16 input_mask; /* 1 = GPIO is input direction, 0 = output */
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};
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static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)
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{
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struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
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struct lp3943 *lp3943 = lp3943_gpio->lp3943;
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/* Return an error if the pin is already assigned */
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if (test_and_set_bit(offset, &lp3943->pin_used))
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return -EBUSY;
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return 0;
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}
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static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset)
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{
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struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
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struct lp3943 *lp3943 = lp3943_gpio->lp3943;
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clear_bit(offset, &lp3943->pin_used);
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}
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static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset,
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u8 val)
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{
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struct lp3943 *lp3943 = lp3943_gpio->lp3943;
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const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
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return lp3943_update_bits(lp3943, mux[offset].reg, mux[offset].mask,
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val << mux[offset].shift);
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}
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static int lp3943_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
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{
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struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
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lp3943_gpio->input_mask |= BIT(offset);
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return lp3943_gpio_set_mode(lp3943_gpio, offset, LP3943_GPIO_IN);
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}
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static int lp3943_get_gpio_in_status(struct lp3943_gpio *lp3943_gpio,
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struct gpio_chip *chip, unsigned offset)
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{
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u8 addr, read;
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int err;
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switch (offset) {
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case LP3943_GPIO1 ... LP3943_GPIO8:
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addr = LP3943_REG_GPIO_A;
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break;
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case LP3943_GPIO9 ... LP3943_GPIO16:
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addr = LP3943_REG_GPIO_B;
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offset = offset - 8;
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break;
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default:
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return -EINVAL;
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}
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err = lp3943_read_byte(lp3943_gpio->lp3943, addr, &read);
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if (err)
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return err;
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return !!(read & BIT(offset));
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}
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static int lp3943_get_gpio_out_status(struct lp3943_gpio *lp3943_gpio,
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struct gpio_chip *chip, unsigned offset)
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{
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struct lp3943 *lp3943 = lp3943_gpio->lp3943;
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const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
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u8 read;
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int err;
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err = lp3943_read_byte(lp3943, mux[offset].reg, &read);
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if (err)
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return err;
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read = (read & mux[offset].mask) >> mux[offset].shift;
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if (read == LP3943_GPIO_OUT_HIGH)
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return 1;
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else if (read == LP3943_GPIO_OUT_LOW)
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return 0;
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else
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return -EINVAL;
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}
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static int lp3943_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
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/*
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* Limitation:
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* LP3943 doesn't have the GPIO direction register. It provides
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* only input and output status registers.
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* So, direction info is required to handle the 'get' operation.
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* This variable is updated whenever the direction is changed and
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* it is used here.
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*/
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if (lp3943_gpio->input_mask & BIT(offset))
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return lp3943_get_gpio_in_status(lp3943_gpio, chip, offset);
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else
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return lp3943_get_gpio_out_status(lp3943_gpio, chip, offset);
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}
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static void lp3943_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
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u8 data;
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if (value)
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data = LP3943_GPIO_OUT_HIGH;
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else
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data = LP3943_GPIO_OUT_LOW;
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lp3943_gpio_set_mode(lp3943_gpio, offset, data);
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}
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static int lp3943_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
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int value)
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{
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struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
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lp3943_gpio_set(chip, offset, value);
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lp3943_gpio->input_mask &= ~BIT(offset);
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return 0;
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}
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static const struct gpio_chip lp3943_gpio_chip = {
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.label = "lp3943",
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.owner = THIS_MODULE,
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.request = lp3943_gpio_request,
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.free = lp3943_gpio_free,
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.direction_input = lp3943_gpio_direction_input,
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.get = lp3943_gpio_get,
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.direction_output = lp3943_gpio_direction_output,
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.set = lp3943_gpio_set,
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.base = -1,
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.ngpio = LP3943_MAX_GPIO,
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.can_sleep = 1,
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};
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static int lp3943_gpio_probe(struct platform_device *pdev)
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{
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struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
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struct lp3943_gpio *lp3943_gpio;
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lp3943_gpio = devm_kzalloc(&pdev->dev, sizeof(*lp3943_gpio),
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GFP_KERNEL);
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if (!lp3943_gpio)
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return -ENOMEM;
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lp3943_gpio->lp3943 = lp3943;
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lp3943_gpio->chip = lp3943_gpio_chip;
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lp3943_gpio->chip.parent = &pdev->dev;
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platform_set_drvdata(pdev, lp3943_gpio);
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return devm_gpiochip_add_data(&pdev->dev, &lp3943_gpio->chip,
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lp3943_gpio);
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}
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static const struct of_device_id lp3943_gpio_of_match[] = {
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{ .compatible = "ti,lp3943-gpio", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, lp3943_gpio_of_match);
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static struct platform_driver lp3943_gpio_driver = {
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.probe = lp3943_gpio_probe,
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.driver = {
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.name = "lp3943-gpio",
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.of_match_table = lp3943_gpio_of_match,
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},
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};
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module_platform_driver(lp3943_gpio_driver);
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MODULE_DESCRIPTION("LP3943 GPIO driver");
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MODULE_ALIAS("platform:lp3943-gpio");
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MODULE_AUTHOR("Milo Kim");
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MODULE_LICENSE("GPL");
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