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 22 static void __iomem *gpio_reg_base; 23 24 static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset) 25 { 26 unsigned long flags; 27 28 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 spin_unlock_irqrestore(&gc->bgpio_lock, flags); 32 33 return 0; 34 } 35 36 static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset) 37 { 38 unsigned long flags; 39 40 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 spin_unlock_irqrestore(&gc->bgpio_lock, flags); 44 } 45 46 static int ls1x_gpio_probe(struct platform_device *pdev) 47 { 48 struct device *dev = &pdev->dev; 49 struct gpio_chip *gc; 50 struct resource *res; 51 int ret; 52 53 gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL); 54 if (!gc) 55 return -ENOMEM; 56 57 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 58 gpio_reg_base = devm_ioremap_resource(dev, res); 59 if (IS_ERR(gpio_reg_base)) 60 return PTR_ERR(gpio_reg_base); 61 62 ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA, 63 gpio_reg_base + GPIO_OUTPUT, NULL, 64 NULL, gpio_reg_base + GPIO_DIR, 0); 65 if (ret) 66 goto err; 67 68 gc->owner = THIS_MODULE; 69 gc->request = ls1x_gpio_request; 70 gc->free = ls1x_gpio_free; 71 gc->base = pdev->id * 32; 72 73 ret = devm_gpiochip_add_data(dev, gc, NULL); 74 if (ret) 75 goto err; 76 77 platform_set_drvdata(pdev, gc); 78 dev_info(dev, "Loongson1 GPIO driver registered\n"); 79 80 return 0; 81 err: 82 dev_err(dev, "failed to register GPIO device\n"); 83 return ret; 84 } 85 86 static struct platform_driver ls1x_gpio_driver = { 87 .probe = ls1x_gpio_probe, 88 .driver = { 89 .name = "ls1x-gpio", 90 }, 91 }; 92 93 module_platform_driver(ls1x_gpio_driver); 94 95 MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>"); 96 MODULE_DESCRIPTION("Loongson1 GPIO driver"); 97 MODULE_LICENSE("GPL"); 98