1 /* 2 * linux/drivers/gpio/gpio-mb86s7x.c 3 * 4 * Copyright (C) 2015 Fujitsu Semiconductor Limited 5 * Copyright (C) 2015 Linaro Ltd. 6 * 7 * This program is free software: you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation, version 2 of the License. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <linux/io.h> 18 #include <linux/init.h> 19 #include <linux/clk.h> 20 #include <linux/module.h> 21 #include <linux/err.h> 22 #include <linux/errno.h> 23 #include <linux/ioport.h> 24 #include <linux/of_device.h> 25 #include <linux/gpio/driver.h> 26 #include <linux/platform_device.h> 27 #include <linux/spinlock.h> 28 #include <linux/slab.h> 29 30 /* 31 * Only first 8bits of a register correspond to each pin, 32 * so there are 4 registers for 32 pins. 33 */ 34 #define PDR(x) (0x0 + x / 8 * 4) 35 #define DDR(x) (0x10 + x / 8 * 4) 36 #define PFR(x) (0x20 + x / 8 * 4) 37 38 #define OFFSET(x) BIT((x) % 8) 39 40 struct mb86s70_gpio_chip { 41 struct gpio_chip gc; 42 void __iomem *base; 43 struct clk *clk; 44 spinlock_t lock; 45 }; 46 47 static int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio) 48 { 49 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc); 50 unsigned long flags; 51 u32 val; 52 53 spin_lock_irqsave(&gchip->lock, flags); 54 55 val = readl(gchip->base + PFR(gpio)); 56 if (!(val & OFFSET(gpio))) { 57 spin_unlock_irqrestore(&gchip->lock, flags); 58 return -EINVAL; 59 } 60 61 val &= ~OFFSET(gpio); 62 writel(val, gchip->base + PFR(gpio)); 63 64 spin_unlock_irqrestore(&gchip->lock, flags); 65 66 return 0; 67 } 68 69 static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio) 70 { 71 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc); 72 unsigned long flags; 73 u32 val; 74 75 spin_lock_irqsave(&gchip->lock, flags); 76 77 val = readl(gchip->base + PFR(gpio)); 78 val |= OFFSET(gpio); 79 writel(val, gchip->base + PFR(gpio)); 80 81 spin_unlock_irqrestore(&gchip->lock, flags); 82 } 83 84 static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio) 85 { 86 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc); 87 unsigned long flags; 88 unsigned char val; 89 90 spin_lock_irqsave(&gchip->lock, flags); 91 92 val = readl(gchip->base + DDR(gpio)); 93 val &= ~OFFSET(gpio); 94 writel(val, gchip->base + DDR(gpio)); 95 96 spin_unlock_irqrestore(&gchip->lock, flags); 97 98 return 0; 99 } 100 101 static int mb86s70_gpio_direction_output(struct gpio_chip *gc, 102 unsigned gpio, int value) 103 { 104 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc); 105 unsigned long flags; 106 unsigned char val; 107 108 spin_lock_irqsave(&gchip->lock, flags); 109 110 val = readl(gchip->base + PDR(gpio)); 111 if (value) 112 val |= OFFSET(gpio); 113 else 114 val &= ~OFFSET(gpio); 115 writel(val, gchip->base + PDR(gpio)); 116 117 val = readl(gchip->base + DDR(gpio)); 118 val |= OFFSET(gpio); 119 writel(val, gchip->base + DDR(gpio)); 120 121 spin_unlock_irqrestore(&gchip->lock, flags); 122 123 return 0; 124 } 125 126 static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio) 127 { 128 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc); 129 130 return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio)); 131 } 132 133 static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value) 134 { 135 struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc); 136 unsigned long flags; 137 unsigned char val; 138 139 spin_lock_irqsave(&gchip->lock, flags); 140 141 val = readl(gchip->base + PDR(gpio)); 142 if (value) 143 val |= OFFSET(gpio); 144 else 145 val &= ~OFFSET(gpio); 146 writel(val, gchip->base + PDR(gpio)); 147 148 spin_unlock_irqrestore(&gchip->lock, flags); 149 } 150 151 static int mb86s70_gpio_probe(struct platform_device *pdev) 152 { 153 struct mb86s70_gpio_chip *gchip; 154 struct resource *res; 155 int ret; 156 157 gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL); 158 if (gchip == NULL) 159 return -ENOMEM; 160 161 platform_set_drvdata(pdev, gchip); 162 163 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 164 gchip->base = devm_ioremap_resource(&pdev->dev, res); 165 if (IS_ERR(gchip->base)) 166 return PTR_ERR(gchip->base); 167 168 gchip->clk = devm_clk_get(&pdev->dev, NULL); 169 if (IS_ERR(gchip->clk)) 170 return PTR_ERR(gchip->clk); 171 172 clk_prepare_enable(gchip->clk); 173 174 spin_lock_init(&gchip->lock); 175 176 gchip->gc.direction_output = mb86s70_gpio_direction_output; 177 gchip->gc.direction_input = mb86s70_gpio_direction_input; 178 gchip->gc.request = mb86s70_gpio_request; 179 gchip->gc.free = mb86s70_gpio_free; 180 gchip->gc.get = mb86s70_gpio_get; 181 gchip->gc.set = mb86s70_gpio_set; 182 gchip->gc.label = dev_name(&pdev->dev); 183 gchip->gc.ngpio = 32; 184 gchip->gc.owner = THIS_MODULE; 185 gchip->gc.parent = &pdev->dev; 186 gchip->gc.base = -1; 187 188 platform_set_drvdata(pdev, gchip); 189 190 ret = gpiochip_add_data(&gchip->gc, gchip); 191 if (ret) { 192 dev_err(&pdev->dev, "couldn't register gpio driver\n"); 193 clk_disable_unprepare(gchip->clk); 194 } 195 196 return ret; 197 } 198 199 static int mb86s70_gpio_remove(struct platform_device *pdev) 200 { 201 struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev); 202 203 gpiochip_remove(&gchip->gc); 204 clk_disable_unprepare(gchip->clk); 205 206 return 0; 207 } 208 209 static const struct of_device_id mb86s70_gpio_dt_ids[] = { 210 { .compatible = "fujitsu,mb86s70-gpio" }, 211 { /* sentinel */ } 212 }; 213 MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids); 214 215 static struct platform_driver mb86s70_gpio_driver = { 216 .driver = { 217 .name = "mb86s70-gpio", 218 .of_match_table = mb86s70_gpio_dt_ids, 219 }, 220 .probe = mb86s70_gpio_probe, 221 .remove = mb86s70_gpio_remove, 222 }; 223 224 static int __init mb86s70_gpio_init(void) 225 { 226 return platform_driver_register(&mb86s70_gpio_driver); 227 } 228 module_init(mb86s70_gpio_init); 229 230 MODULE_DESCRIPTION("MB86S7x GPIO Driver"); 231 MODULE_ALIAS("platform:mb86s70-gpio"); 232 MODULE_LICENSE("GPL"); 233