1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * GPIO Driver for Loongson 1 SoC 4 * 5 * Copyright (C) 2015-2023 Keguang Zhang <keguang.zhang@gmail.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/gpio/driver.h> 10 #include <linux/platform_device.h> 11 #include <linux/bitops.h> 12 13 /* Loongson 1 GPIO Register Definitions */ 14 #define GPIO_CFG 0x0 15 #define GPIO_DIR 0x10 16 #define GPIO_DATA 0x20 17 #define GPIO_OUTPUT 0x30 18 19 struct ls1x_gpio_chip { 20 struct gpio_chip gc; 21 void __iomem *reg_base; 22 }; 23 24 static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset) 25 { 26 struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc); 27 unsigned long flags; 28 29 raw_spin_lock_irqsave(&gc->bgpio_lock, flags); 30 __raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) | BIT(offset), 31 ls1x_gc->reg_base + GPIO_CFG); 32 raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags); 33 34 return 0; 35 } 36 37 static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset) 38 { 39 struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc); 40 unsigned long flags; 41 42 raw_spin_lock_irqsave(&gc->bgpio_lock, flags); 43 __raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) & ~BIT(offset), 44 ls1x_gc->reg_base + GPIO_CFG); 45 raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags); 46 } 47 48 static int ls1x_gpio_probe(struct platform_device *pdev) 49 { 50 struct device *dev = &pdev->dev; 51 struct ls1x_gpio_chip *ls1x_gc; 52 int ret; 53 54 ls1x_gc = devm_kzalloc(dev, sizeof(*ls1x_gc), GFP_KERNEL); 55 if (!ls1x_gc) 56 return -ENOMEM; 57 58 ls1x_gc->reg_base = devm_platform_ioremap_resource(pdev, 0); 59 if (IS_ERR(ls1x_gc->reg_base)) 60 return PTR_ERR(ls1x_gc->reg_base); 61 62 ret = bgpio_init(&ls1x_gc->gc, dev, 4, ls1x_gc->reg_base + GPIO_DATA, 63 ls1x_gc->reg_base + GPIO_OUTPUT, NULL, 64 NULL, ls1x_gc->reg_base + GPIO_DIR, 0); 65 if (ret) 66 goto err; 67 68 ls1x_gc->gc.owner = THIS_MODULE; 69 ls1x_gc->gc.request = ls1x_gpio_request; 70 ls1x_gc->gc.free = ls1x_gpio_free; 71 /* 72 * Clear ngpio to let gpiolib get the correct number 73 * by reading ngpios property 74 */ 75 ls1x_gc->gc.ngpio = 0; 76 77 ret = devm_gpiochip_add_data(dev, &ls1x_gc->gc, ls1x_gc); 78 if (ret) 79 goto err; 80 81 platform_set_drvdata(pdev, ls1x_gc); 82 83 dev_info(dev, "GPIO controller registered with %d pins\n", 84 ls1x_gc->gc.ngpio); 85 86 return 0; 87 err: 88 dev_err(dev, "failed to register GPIO controller\n"); 89 return ret; 90 } 91 92 static const struct of_device_id ls1x_gpio_dt_ids[] = { 93 { .compatible = "loongson,ls1x-gpio" }, 94 { /* sentinel */ } 95 }; 96 MODULE_DEVICE_TABLE(of, ls1x_gpio_dt_ids); 97 98 static struct platform_driver ls1x_gpio_driver = { 99 .probe = ls1x_gpio_probe, 100 .driver = { 101 .name = "ls1x-gpio", 102 .of_match_table = ls1x_gpio_dt_ids, 103 }, 104 }; 105 106 module_platform_driver(ls1x_gpio_driver); 107 108 MODULE_AUTHOR("Keguang Zhang <keguang.zhang@gmail.com>"); 109 MODULE_DESCRIPTION("Loongson1 GPIO driver"); 110 MODULE_LICENSE("GPL"); 111