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 15 /* Loongson 1 GPIO Register Definitions */ 16 #define GPIO_CFG 0x0 17 #define GPIO_DIR 0x10 18 #define GPIO_DATA 0x20 19 #define GPIO_OUTPUT 0x30 20 21 static void __iomem *gpio_reg_base; 22 23 static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset) 24 { 25 unsigned long pinmask = gc->pin2mask(gc, offset); 26 unsigned long flags; 27 28 spin_lock_irqsave(&gc->bgpio_lock, flags); 29 __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | pinmask, 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 pinmask = gc->pin2mask(gc, offset); 39 unsigned long flags; 40 41 spin_lock_irqsave(&gc->bgpio_lock, flags); 42 __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~pinmask, 43 gpio_reg_base + GPIO_CFG); 44 spin_unlock_irqrestore(&gc->bgpio_lock, flags); 45 } 46 47 static int ls1x_gpio_probe(struct platform_device *pdev) 48 { 49 struct device *dev = &pdev->dev; 50 struct gpio_chip *gc; 51 struct resource *res; 52 int ret; 53 54 gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL); 55 if (!gc) 56 return -ENOMEM; 57 58 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 59 gpio_reg_base = devm_ioremap_resource(dev, res); 60 if (IS_ERR(gpio_reg_base)) 61 return PTR_ERR(gpio_reg_base); 62 63 ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA, 64 gpio_reg_base + GPIO_OUTPUT, NULL, 65 NULL, gpio_reg_base + GPIO_DIR, 0); 66 if (ret) 67 goto err; 68 69 gc->owner = THIS_MODULE; 70 gc->request = ls1x_gpio_request; 71 gc->free = ls1x_gpio_free; 72 gc->base = pdev->id * 32; 73 74 ret = devm_gpiochip_add_data(dev, gc, NULL); 75 if (ret) 76 goto err; 77 78 platform_set_drvdata(pdev, gc); 79 dev_info(dev, "Loongson1 GPIO driver registered\n"); 80 81 return 0; 82 err: 83 dev_err(dev, "failed to register GPIO device\n"); 84 return ret; 85 } 86 87 static struct platform_driver ls1x_gpio_driver = { 88 .probe = ls1x_gpio_probe, 89 .driver = { 90 .name = "ls1x-gpio", 91 }, 92 }; 93 94 module_platform_driver(ls1x_gpio_driver); 95 96 MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>"); 97 MODULE_DESCRIPTION("Loongson1 GPIO driver"); 98 MODULE_LICENSE("GPL"); 99