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 struct mmio_74xx_gpio_priv *priv; 109 struct resource *res; 110 void __iomem *dat; 111 int err; 112 113 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 114 if (!priv) 115 return -ENOMEM; 116 117 priv->flags = (uintptr_t)of_device_get_match_data(&pdev->dev); 118 119 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 120 dat = devm_ioremap_resource(&pdev->dev, res); 121 if (IS_ERR(dat)) 122 return PTR_ERR(dat); 123 124 err = bgpio_init(&priv->gc, &pdev->dev, 125 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8), 126 dat, NULL, NULL, NULL, NULL, 0); 127 if (err) 128 return err; 129 130 priv->gc.direction_input = mmio_74xx_dir_in; 131 priv->gc.direction_output = mmio_74xx_dir_out; 132 priv->gc.get_direction = mmio_74xx_get_direction; 133 priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags); 134 priv->gc.owner = THIS_MODULE; 135 136 platform_set_drvdata(pdev, priv); 137 138 return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv); 139 } 140 141 static struct platform_driver mmio_74xx_gpio_driver = { 142 .driver = { 143 .name = "74xx-mmio-gpio", 144 .of_match_table = mmio_74xx_gpio_ids, 145 }, 146 .probe = mmio_74xx_gpio_probe, 147 }; 148 module_platform_driver(mmio_74xx_gpio_driver); 149 150 MODULE_LICENSE("GPL"); 151 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); 152 MODULE_DESCRIPTION("74xx MMIO GPIO driver"); 153