234 строки
6.2 KiB
C
234 строки
6.2 KiB
C
/*
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* RDC321x GPIO driver
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*
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* Copyright (C) 2008, Volker Weiss <dev@tintuc.de>
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* Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
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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; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/platform_device.h>
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#include <linux/pci.h>
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#include <linux/gpio.h>
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#include <linux/mfd/rdc321x.h>
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#include <linux/slab.h>
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struct rdc321x_gpio {
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spinlock_t lock;
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struct pci_dev *sb_pdev;
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u32 data_reg[2];
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int reg1_ctrl_base;
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int reg1_data_base;
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int reg2_ctrl_base;
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int reg2_data_base;
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struct gpio_chip chip;
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};
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/* read GPIO pin */
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static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
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{
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struct rdc321x_gpio *gpch;
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u32 value = 0;
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int reg;
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gpch = container_of(chip, struct rdc321x_gpio, chip);
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reg = gpio < 32 ? gpch->reg1_data_base : gpch->reg2_data_base;
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spin_lock(&gpch->lock);
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pci_write_config_dword(gpch->sb_pdev, reg,
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gpch->data_reg[gpio < 32 ? 0 : 1]);
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pci_read_config_dword(gpch->sb_pdev, reg, &value);
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spin_unlock(&gpch->lock);
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return (1 << (gpio & 0x1f)) & value ? 1 : 0;
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}
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static void rdc_gpio_set_value_impl(struct gpio_chip *chip,
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unsigned gpio, int value)
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{
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struct rdc321x_gpio *gpch;
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int reg = (gpio < 32) ? 0 : 1;
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gpch = container_of(chip, struct rdc321x_gpio, chip);
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if (value)
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gpch->data_reg[reg] |= 1 << (gpio & 0x1f);
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else
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gpch->data_reg[reg] &= ~(1 << (gpio & 0x1f));
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pci_write_config_dword(gpch->sb_pdev,
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reg ? gpch->reg2_data_base : gpch->reg1_data_base,
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gpch->data_reg[reg]);
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}
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/* set GPIO pin to value */
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static void rdc_gpio_set_value(struct gpio_chip *chip,
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unsigned gpio, int value)
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{
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struct rdc321x_gpio *gpch;
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gpch = container_of(chip, struct rdc321x_gpio, chip);
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spin_lock(&gpch->lock);
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rdc_gpio_set_value_impl(chip, gpio, value);
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spin_unlock(&gpch->lock);
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}
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static int rdc_gpio_config(struct gpio_chip *chip,
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unsigned gpio, int value)
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{
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struct rdc321x_gpio *gpch;
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int err;
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u32 reg;
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gpch = container_of(chip, struct rdc321x_gpio, chip);
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spin_lock(&gpch->lock);
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err = pci_read_config_dword(gpch->sb_pdev, gpio < 32 ?
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gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, ®);
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if (err)
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goto unlock;
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reg |= 1 << (gpio & 0x1f);
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err = pci_write_config_dword(gpch->sb_pdev, gpio < 32 ?
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gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, reg);
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if (err)
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goto unlock;
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rdc_gpio_set_value_impl(chip, gpio, value);
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unlock:
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spin_unlock(&gpch->lock);
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return err;
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}
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/* configure GPIO pin as input */
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static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
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{
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return rdc_gpio_config(chip, gpio, 1);
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}
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/*
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* Cache the initial value of both GPIO data registers
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*/
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static int rdc321x_gpio_probe(struct platform_device *pdev)
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{
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int err;
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struct resource *r;
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struct rdc321x_gpio *rdc321x_gpio_dev;
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struct rdc321x_gpio_pdata *pdata;
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pdata = pdev->dev.platform_data;
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if (!pdata) {
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dev_err(&pdev->dev, "no platform data supplied\n");
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return -ENODEV;
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}
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rdc321x_gpio_dev = kzalloc(sizeof(struct rdc321x_gpio), GFP_KERNEL);
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if (!rdc321x_gpio_dev) {
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dev_err(&pdev->dev, "failed to allocate private data\n");
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return -ENOMEM;
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}
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r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg1");
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if (!r) {
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dev_err(&pdev->dev, "failed to get gpio-reg1 resource\n");
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err = -ENODEV;
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goto out_free;
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}
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spin_lock_init(&rdc321x_gpio_dev->lock);
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rdc321x_gpio_dev->sb_pdev = pdata->sb_pdev;
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rdc321x_gpio_dev->reg1_ctrl_base = r->start;
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rdc321x_gpio_dev->reg1_data_base = r->start + 0x4;
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r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg2");
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if (!r) {
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dev_err(&pdev->dev, "failed to get gpio-reg2 resource\n");
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err = -ENODEV;
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goto out_free;
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}
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rdc321x_gpio_dev->reg2_ctrl_base = r->start;
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rdc321x_gpio_dev->reg2_data_base = r->start + 0x4;
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rdc321x_gpio_dev->chip.label = "rdc321x-gpio";
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rdc321x_gpio_dev->chip.owner = THIS_MODULE;
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rdc321x_gpio_dev->chip.direction_input = rdc_gpio_direction_input;
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rdc321x_gpio_dev->chip.direction_output = rdc_gpio_config;
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rdc321x_gpio_dev->chip.get = rdc_gpio_get_value;
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rdc321x_gpio_dev->chip.set = rdc_gpio_set_value;
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rdc321x_gpio_dev->chip.base = 0;
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rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios;
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platform_set_drvdata(pdev, rdc321x_gpio_dev);
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/* This might not be, what others (BIOS, bootloader, etc.)
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wrote to these registers before, but it's a good guess. Still
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better than just using 0xffffffff. */
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err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev,
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rdc321x_gpio_dev->reg1_data_base,
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&rdc321x_gpio_dev->data_reg[0]);
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if (err)
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goto out_free;
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err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev,
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rdc321x_gpio_dev->reg2_data_base,
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&rdc321x_gpio_dev->data_reg[1]);
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if (err)
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goto out_free;
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dev_info(&pdev->dev, "registering %d GPIOs\n",
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rdc321x_gpio_dev->chip.ngpio);
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return gpiochip_add(&rdc321x_gpio_dev->chip);
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out_free:
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kfree(rdc321x_gpio_dev);
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return err;
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}
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static int rdc321x_gpio_remove(struct platform_device *pdev)
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{
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int ret;
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struct rdc321x_gpio *rdc321x_gpio_dev = platform_get_drvdata(pdev);
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ret = gpiochip_remove(&rdc321x_gpio_dev->chip);
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if (ret)
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dev_err(&pdev->dev, "failed to unregister chip\n");
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kfree(rdc321x_gpio_dev);
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return ret;
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}
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static struct platform_driver rdc321x_gpio_driver = {
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.driver.name = "rdc321x-gpio",
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.driver.owner = THIS_MODULE,
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.probe = rdc321x_gpio_probe,
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.remove = rdc321x_gpio_remove,
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};
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module_platform_driver(rdc321x_gpio_driver);
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MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
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MODULE_DESCRIPTION("RDC321x GPIO driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:rdc321x-gpio");
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