1 /* 2 * 74xx MMIO GPIO driver 3 * 4 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 */ 11 12 #include <linux/err.h> 13 #include <linux/module.h> 14 #include <linux/of_device.h> 15 #include <linux/gpio/driver.h> 16 #include <linux/platform_device.h> 17 18 #define MMIO_74XX_DIR_IN (0 << 8) 19 #define MMIO_74XX_DIR_OUT (1 << 8) 20 #define MMIO_74XX_BIT_CNT(x) ((x) & 0xff) 21 22 struct mmio_74xx_gpio_priv { 23 struct gpio_chip gc; 24 unsigned flags; 25 }; 26 27 static const struct of_device_id mmio_74xx_gpio_ids[] = { 28 { 29 .compatible = "ti,741g125", 30 .data = (const void *)(MMIO_74XX_DIR_IN | 1), 31 }, 32 { 33 .compatible = "ti,742g125", 34 .data = (const void *)(MMIO_74XX_DIR_IN | 2), 35 }, 36 { 37 .compatible = "ti,74125", 38 .data = (const void *)(MMIO_74XX_DIR_IN | 4), 39 }, 40 { 41 .compatible = "ti,74365", 42 .data = (const void *)(MMIO_74XX_DIR_IN | 6), 43 }, 44 { 45 .compatible = "ti,74244", 46 .data = (const void *)(MMIO_74XX_DIR_IN | 8), 47 }, 48 { 49 .compatible = "ti,741624", 50 .data = (const void *)(MMIO_74XX_DIR_IN | 16), 51 }, 52 { 53 .compatible = "ti,741g74", 54 .data = (const void *)(MMIO_74XX_DIR_OUT | 1), 55 }, 56 { 57 .compatible = "ti,7474", 58 .data = (const void *)(MMIO_74XX_DIR_OUT | 2), 59 }, 60 { 61 .compatible = "ti,74175", 62 .data = (const void *)(MMIO_74XX_DIR_OUT | 4), 63 }, 64 { 65 .compatible = "ti,74174", 66 .data = (const void *)(MMIO_74XX_DIR_OUT | 6), 67 }, 68 { 69 .compatible = "ti,74273", 70 .data = (const void *)(MMIO_74XX_DIR_OUT | 8), 71 }, 72 { 73 .compatible = "ti,7416374", 74 .data = (const void *)(MMIO_74XX_DIR_OUT | 16), 75 }, 76 { } 77 }; 78 MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids); 79 80 static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset) 81 { 82 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc); 83 84 return !(priv->flags & MMIO_74XX_DIR_OUT); 85 } 86 87 static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio) 88 { 89 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc); 90 91 return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0; 92 } 93 94 static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) 95 { 96 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc); 97 98 if (priv->flags & MMIO_74XX_DIR_OUT) { 99 gc->set(gc, gpio, val); 100 return 0; 101 } 102 103 return -ENOTSUPP; 104 } 105 106 static int mmio_74xx_gpio_probe(struct platform_device *pdev) 107 { 108 const struct of_device_id *of_id; 109 struct mmio_74xx_gpio_priv *priv; 110 struct resource *res; 111 void __iomem *dat; 112 int err; 113 114 of_id = of_match_device(mmio_74xx_gpio_ids, &pdev->dev); 115 if (!of_id) 116 return -ENODEV; 117 118 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 119 if (!priv) 120 return -ENOMEM; 121 122 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 123 dat = devm_ioremap_resource(&pdev->dev, res); 124 if (IS_ERR(dat)) 125 return PTR_ERR(dat); 126 127 priv->flags = (uintptr_t) of_id->data; 128 129 err = bgpio_init(&priv->gc, &pdev->dev, 130 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8), 131 dat, NULL, NULL, NULL, NULL, 0); 132 if (err) 133 return err; 134 135 priv->gc.direction_input = mmio_74xx_dir_in; 136 priv->gc.direction_output = mmio_74xx_dir_out; 137 priv->gc.get_direction = mmio_74xx_get_direction; 138 priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags); 139 priv->gc.owner = THIS_MODULE; 140 141 platform_set_drvdata(pdev, priv); 142 143 return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv); 144 } 145 146 static struct platform_driver mmio_74xx_gpio_driver = { 147 .driver = { 148 .name = "74xx-mmio-gpio", 149 .of_match_table = mmio_74xx_gpio_ids, 150 }, 151 .probe = mmio_74xx_gpio_probe, 152 }; 153 module_platform_driver(mmio_74xx_gpio_driver); 154 155 MODULE_LICENSE("GPL"); 156 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); 157 MODULE_DESCRIPTION("74xx MMIO GPIO driver"); 158