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/gpio/driver.h> 12 #include <linux/platform_device.h> 13 14 /* Loongson 1 GPIO Register Definitions */ 15 #define GPIO_CFG 0x0 16 #define GPIO_DIR 0x10 17 #define GPIO_DATA 0x20 18 #define GPIO_OUTPUT 0x30 19 20 static void __iomem *gpio_reg_base; 21 22 static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset) 23 { 24 unsigned long pinmask = gc->pin2mask(gc, offset); 25 unsigned long flags; 26 27 spin_lock_irqsave(&gc->bgpio_lock, flags); 28 __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | pinmask, 29 gpio_reg_base + GPIO_CFG); 30 spin_unlock_irqrestore(&gc->bgpio_lock, flags); 31 32 return 0; 33 } 34 35 static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset) 36 { 37 unsigned long pinmask = gc->pin2mask(gc, offset); 38 unsigned long flags; 39 40 spin_lock_irqsave(&gc->bgpio_lock, flags); 41 __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~pinmask, 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 if (!res) { 59 dev_err(dev, "failed to get I/O memory\n"); 60 return -EINVAL; 61 } 62 63 gpio_reg_base = devm_ioremap_resource(dev, res); 64 if (IS_ERR(gpio_reg_base)) 65 return PTR_ERR(gpio_reg_base); 66 67 ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA, 68 gpio_reg_base + GPIO_OUTPUT, NULL, 69 NULL, gpio_reg_base + GPIO_DIR, 0); 70 if (ret) 71 goto err; 72 73 gc->owner = THIS_MODULE; 74 gc->request = ls1x_gpio_request; 75 gc->free = ls1x_gpio_free; 76 gc->base = pdev->id * 32; 77 78 ret = devm_gpiochip_add_data(dev, gc, NULL); 79 if (ret) 80 goto err; 81 82 platform_set_drvdata(pdev, gc); 83 dev_info(dev, "Loongson1 GPIO driver registered\n"); 84 85 return 0; 86 err: 87 dev_err(dev, "failed to register GPIO device\n"); 88 return ret; 89 } 90 91 static struct platform_driver ls1x_gpio_driver = { 92 .probe = ls1x_gpio_probe, 93 .driver = { 94 .name = "ls1x-gpio", 95 }, 96 }; 97 98 module_platform_driver(ls1x_gpio_driver); 99 100 MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>"); 101 MODULE_DESCRIPTION("Loongson1 GPIO driver"); 102 MODULE_LICENSE("GPL"); 103