/*
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* GPIO Driver for Loongson 1 SoC
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*
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* Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/module.h>
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#include <linux/gpio/driver.h>
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#include <linux/platform_device.h>
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#include <linux/bitops.h>
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/* Loongson 1 GPIO Register Definitions */
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#define GPIO_CFG 0x0
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#define GPIO_DIR 0x10
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#define GPIO_DATA 0x20
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#define GPIO_OUTPUT 0x30
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static void __iomem *gpio_reg_base;
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static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
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{
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unsigned long flags;
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spin_lock_irqsave(&gc->bgpio_lock, flags);
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__raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | BIT(offset),
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gpio_reg_base + GPIO_CFG);
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spin_unlock_irqrestore(&gc->bgpio_lock, flags);
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return 0;
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}
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static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
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{
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unsigned long flags;
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spin_lock_irqsave(&gc->bgpio_lock, flags);
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__raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~BIT(offset),
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gpio_reg_base + GPIO_CFG);
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spin_unlock_irqrestore(&gc->bgpio_lock, flags);
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}
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static int ls1x_gpio_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct gpio_chip *gc;
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int ret;
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gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
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if (!gc)
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return -ENOMEM;
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gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(gpio_reg_base))
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return PTR_ERR(gpio_reg_base);
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ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA,
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gpio_reg_base + GPIO_OUTPUT, NULL,
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NULL, gpio_reg_base + GPIO_DIR, 0);
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if (ret)
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goto err;
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gc->owner = THIS_MODULE;
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gc->request = ls1x_gpio_request;
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gc->free = ls1x_gpio_free;
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gc->base = pdev->id * 32;
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ret = devm_gpiochip_add_data(dev, gc, NULL);
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if (ret)
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goto err;
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platform_set_drvdata(pdev, gc);
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dev_info(dev, "Loongson1 GPIO driver registered\n");
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return 0;
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err:
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dev_err(dev, "failed to register GPIO device\n");
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return ret;
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}
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static struct platform_driver ls1x_gpio_driver = {
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.probe = ls1x_gpio_probe,
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.driver = {
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.name = "ls1x-gpio",
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},
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};
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module_platform_driver(ls1x_gpio_driver);
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MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
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MODULE_DESCRIPTION("Loongson1 GPIO driver");
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MODULE_LICENSE("GPL");
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