1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * Loongson GPIO Support 4 * 5 * Copyright (C) 2022-2023 Loongson Technology Corporation Limited 6 */ 7 8#include <linux/kernel.h> 9#include <linux/init.h> 10#include <linux/module.h> 11#include <linux/spinlock.h> 12#include <linux/err.h> 13#include <linux/gpio/driver.h> 14#include <linux/platform_device.h> 15#include <linux/bitops.h> 16#include <asm/types.h> 17 18enum loongson_gpio_mode { 19 BIT_CTRL_MODE, 20 BYTE_CTRL_MODE, 21}; 22 23struct loongson_gpio_chip_data { 24 const char *label; 25 enum loongson_gpio_mode mode; 26 unsigned int conf_offset; 27 unsigned int out_offset; 28 unsigned int in_offset; 29}; 30 31struct loongson_gpio_chip { 32 struct gpio_chip chip; 33 struct fwnode_handle *fwnode; 34 spinlock_t lock; 35 void __iomem *reg_base; 36 const struct loongson_gpio_chip_data *chip_data; 37}; 38 39static inline struct loongson_gpio_chip *to_loongson_gpio_chip(struct gpio_chip *chip) 40{ 41 return container_of(chip, struct loongson_gpio_chip, chip); 42} 43 44static inline void loongson_commit_direction(struct loongson_gpio_chip *lgpio, unsigned int pin, 45 int input) 46{ 47 u8 bval = input ? 1 : 0; 48 49 writeb(bval, lgpio->reg_base + lgpio->chip_data->conf_offset + pin); 50} 51 52static void loongson_commit_level(struct loongson_gpio_chip *lgpio, unsigned int pin, int high) 53{ 54 u8 bval = high ? 1 : 0; 55 56 writeb(bval, lgpio->reg_base + lgpio->chip_data->out_offset + pin); 57} 58 59static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned int pin) 60{ 61 unsigned long flags; 62 struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip); 63 64 spin_lock_irqsave(&lgpio->lock, flags); 65 loongson_commit_direction(lgpio, pin, 1); 66 spin_unlock_irqrestore(&lgpio->lock, flags); 67 68 return 0; 69} 70 71static int loongson_gpio_direction_output(struct gpio_chip *chip, unsigned int pin, int value) 72{ 73 unsigned long flags; 74 struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip); 75 76 spin_lock_irqsave(&lgpio->lock, flags); 77 loongson_commit_level(lgpio, pin, value); 78 loongson_commit_direction(lgpio, pin, 0); 79 spin_unlock_irqrestore(&lgpio->lock, flags); 80 81 return 0; 82} 83 84static int loongson_gpio_get(struct gpio_chip *chip, unsigned int pin) 85{ 86 u8 bval; 87 int val; 88 struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip); 89 90 bval = readb(lgpio->reg_base + lgpio->chip_data->in_offset + pin); 91 val = bval & 1; 92 93 return val; 94} 95 96static int loongson_gpio_get_direction(struct gpio_chip *chip, unsigned int pin) 97{ 98 u8 bval; 99 struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip); 100 101 bval = readb(lgpio->reg_base + lgpio->chip_data->conf_offset + pin); 102 if (bval & 1) 103 return GPIO_LINE_DIRECTION_IN; 104 105 return GPIO_LINE_DIRECTION_OUT; 106} 107 108static void loongson_gpio_set(struct gpio_chip *chip, unsigned int pin, int value) 109{ 110 unsigned long flags; 111 struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip); 112 113 spin_lock_irqsave(&lgpio->lock, flags); 114 loongson_commit_level(lgpio, pin, value); 115 spin_unlock_irqrestore(&lgpio->lock, flags); 116} 117 118static int loongson_gpio_to_irq(struct gpio_chip *chip, unsigned int offset) 119{ 120 struct platform_device *pdev = to_platform_device(chip->parent); 121 122 return platform_get_irq(pdev, offset); 123} 124 125static int loongson_gpio_init(struct device *dev, struct loongson_gpio_chip *lgpio, 126 struct device_node *np, void __iomem *reg_base) 127{ 128 int ret; 129 u32 ngpios; 130 131 lgpio->reg_base = reg_base; 132 133 if (lgpio->chip_data->mode == BIT_CTRL_MODE) { 134 ret = bgpio_init(&lgpio->chip, dev, 8, 135 lgpio->reg_base + lgpio->chip_data->in_offset, 136 lgpio->reg_base + lgpio->chip_data->out_offset, 137 NULL, NULL, 138 lgpio->reg_base + lgpio->chip_data->conf_offset, 139 0); 140 if (ret) { 141 dev_err(dev, "unable to init generic GPIO\n"); 142 return ret; 143 } 144 } else { 145 lgpio->chip.direction_input = loongson_gpio_direction_input; 146 lgpio->chip.get = loongson_gpio_get; 147 lgpio->chip.get_direction = loongson_gpio_get_direction; 148 lgpio->chip.direction_output = loongson_gpio_direction_output; 149 lgpio->chip.set = loongson_gpio_set; 150 lgpio->chip.parent = dev; 151 spin_lock_init(&lgpio->lock); 152 } 153 154 device_property_read_u32(dev, "ngpios", &ngpios); 155 156 lgpio->chip.can_sleep = 0; 157 lgpio->chip.ngpio = ngpios; 158 lgpio->chip.label = lgpio->chip_data->label; 159 lgpio->chip.to_irq = loongson_gpio_to_irq; 160 161 return devm_gpiochip_add_data(dev, &lgpio->chip, lgpio); 162} 163 164static int loongson_gpio_probe(struct platform_device *pdev) 165{ 166 void __iomem *reg_base; 167 struct loongson_gpio_chip *lgpio; 168 struct device_node *np = pdev->dev.of_node; 169 struct device *dev = &pdev->dev; 170 171 lgpio = devm_kzalloc(dev, sizeof(*lgpio), GFP_KERNEL); 172 if (!lgpio) 173 return -ENOMEM; 174 175 lgpio->chip_data = device_get_match_data(dev); 176 177 reg_base = devm_platform_ioremap_resource(pdev, 0); 178 if (IS_ERR(reg_base)) 179 return PTR_ERR(reg_base); 180 181 return loongson_gpio_init(dev, lgpio, np, reg_base); 182} 183 184static const struct loongson_gpio_chip_data loongson_gpio_ls2k_data = { 185 .label = "ls2k_gpio", 186 .mode = BIT_CTRL_MODE, 187 .conf_offset = 0x0, 188 .in_offset = 0x20, 189 .out_offset = 0x10, 190}; 191 192static const struct loongson_gpio_chip_data loongson_gpio_ls7a_data = { 193 .label = "ls7a_gpio", 194 .mode = BYTE_CTRL_MODE, 195 .conf_offset = 0x800, 196 .in_offset = 0xa00, 197 .out_offset = 0x900, 198}; 199 200static const struct of_device_id loongson_gpio_of_match[] = { 201 { 202 .compatible = "loongson,ls2k-gpio", 203 .data = &loongson_gpio_ls2k_data, 204 }, 205 { 206 .compatible = "loongson,ls7a-gpio", 207 .data = &loongson_gpio_ls7a_data, 208 }, 209 {} 210}; 211MODULE_DEVICE_TABLE(of, loongson_gpio_of_match); 212 213static const struct acpi_device_id loongson_gpio_acpi_match[] = { 214 { 215 .id = "LOON0002", 216 .driver_data = (kernel_ulong_t)&loongson_gpio_ls7a_data, 217 }, 218 {} 219}; 220MODULE_DEVICE_TABLE(acpi, loongson_gpio_acpi_match); 221 222static struct platform_driver loongson_gpio_driver = { 223 .driver = { 224 .name = "loongson-gpio", 225 .of_match_table = loongson_gpio_of_match, 226 .acpi_match_table = loongson_gpio_acpi_match, 227 }, 228 .probe = loongson_gpio_probe, 229}; 230 231static int __init loongson_gpio_setup(void) 232{ 233 return platform_driver_register(&loongson_gpio_driver); 234} 235postcore_initcall(loongson_gpio_setup); 236 237MODULE_DESCRIPTION("Loongson gpio driver"); 238MODULE_LICENSE("GPL"); 239