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