cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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gpio-loongson1.c (2345B)

      1/*
      2 * GPIO Driver for Loongson 1 SoC
      3 *
      4 * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>
      5 *
      6 * This file is licensed under the terms of the GNU General Public
      7 * License version 2. This program is licensed "as is" without any
      8 * warranty of any kind, whether express or implied.
      9 */
     10
     11#include <linux/module.h>
     12#include <linux/gpio/driver.h>
     13#include <linux/platform_device.h>
     14#include <linux/bitops.h>
     15
     16/* Loongson 1 GPIO Register Definitions */
     17#define GPIO_CFG		0x0
     18#define GPIO_DIR		0x10
     19#define GPIO_DATA		0x20
     20#define GPIO_OUTPUT		0x30
     21
     22static void __iomem *gpio_reg_base;
     23
     24static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
     25{
     26	unsigned long flags;
     27
     28	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
     29	__raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | BIT(offset),
     30		     gpio_reg_base + GPIO_CFG);
     31	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
     32
     33	return 0;
     34}
     35
     36static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
     37{
     38	unsigned long flags;
     39
     40	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
     41	__raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~BIT(offset),
     42		     gpio_reg_base + GPIO_CFG);
     43	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
     44}
     45
     46static int ls1x_gpio_probe(struct platform_device *pdev)
     47{
     48	struct device *dev = &pdev->dev;
     49	struct gpio_chip *gc;
     50	int ret;
     51
     52	gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
     53	if (!gc)
     54		return -ENOMEM;
     55
     56	gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
     57	if (IS_ERR(gpio_reg_base))
     58		return PTR_ERR(gpio_reg_base);
     59
     60	ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA,
     61			 gpio_reg_base + GPIO_OUTPUT, NULL,
     62			 NULL, gpio_reg_base + GPIO_DIR, 0);
     63	if (ret)
     64		goto err;
     65
     66	gc->owner = THIS_MODULE;
     67	gc->request = ls1x_gpio_request;
     68	gc->free = ls1x_gpio_free;
     69	gc->base = pdev->id * 32;
     70
     71	ret = devm_gpiochip_add_data(dev, gc, NULL);
     72	if (ret)
     73		goto err;
     74
     75	platform_set_drvdata(pdev, gc);
     76	dev_info(dev, "Loongson1 GPIO driver registered\n");
     77
     78	return 0;
     79err:
     80	dev_err(dev, "failed to register GPIO device\n");
     81	return ret;
     82}
     83
     84static struct platform_driver ls1x_gpio_driver = {
     85	.probe	= ls1x_gpio_probe,
     86	.driver	= {
     87		.name	= "ls1x-gpio",
     88	},
     89};
     90
     91module_platform_driver(ls1x_gpio_driver);
     92
     93MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
     94MODULE_DESCRIPTION("Loongson1 GPIO driver");
     95MODULE_LICENSE("GPL");