1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 74xx MMIO GPIO driver 4 * 5 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru> 6 */ 7 8 #include <linux/err.h> 9 #include <linux/module.h> 10 #include <linux/of_device.h> 11 #include <linux/gpio/driver.h> 12 #include <linux/platform_device.h> 13 14 #define MMIO_74XX_DIR_IN (0 << 8) 15 #define MMIO_74XX_DIR_OUT (1 << 8) 16 #define MMIO_74XX_BIT_CNT(x) ((x) & 0xff) 17 18 struct mmio_74xx_gpio_priv { 19 struct gpio_chip gc; 20 unsigned flags; 21 }; 22 23 static const struct of_device_id mmio_74xx_gpio_ids[] = { 24 { 25 .compatible = "ti,741g125", 26 .data = (const void *)(MMIO_74XX_DIR_IN | 1), 27 }, 28 { 29 .compatible = "ti,742g125", 30 .data = (const void *)(MMIO_74XX_DIR_IN | 2), 31 }, 32 { 33 .compatible = "ti,74125", 34 .data = (const void *)(MMIO_74XX_DIR_IN | 4), 35 }, 36 { 37 .compatible = "ti,74365", 38 .data = (const void *)(MMIO_74XX_DIR_IN | 6), 39 }, 40 { 41 .compatible = "ti,74244", 42 .data = (const void *)(MMIO_74XX_DIR_IN | 8), 43 }, 44 { 45 .compatible = "ti,741624", 46 .data = (const void *)(MMIO_74XX_DIR_IN | 16), 47 }, 48 { 49 .compatible = "ti,741g74", 50 .data = (const void *)(MMIO_74XX_DIR_OUT | 1), 51 }, 52 { 53 .compatible = "ti,7474", 54 .data = (const void *)(MMIO_74XX_DIR_OUT | 2), 55 }, 56 { 57 .compatible = "ti,74175", 58 .data = (const void *)(MMIO_74XX_DIR_OUT | 4), 59 }, 60 { 61 .compatible = "ti,74174", 62 .data = (const void *)(MMIO_74XX_DIR_OUT | 6), 63 }, 64 { 65 .compatible = "ti,74273", 66 .data = (const void *)(MMIO_74XX_DIR_OUT | 8), 67 }, 68 { 69 .compatible = "ti,7416374", 70 .data = (const void *)(MMIO_74XX_DIR_OUT | 16), 71 }, 72 { } 73 }; 74 MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids); 75 76 static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset) 77 { 78 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc); 79 80 return !(priv->flags & MMIO_74XX_DIR_OUT); 81 } 82 83 static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio) 84 { 85 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc); 86 87 return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0; 88 } 89 90 static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) 91 { 92 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc); 93 94 if (priv->flags & MMIO_74XX_DIR_OUT) { 95 gc->set(gc, gpio, val); 96 return 0; 97 } 98 99 return -ENOTSUPP; 100 } 101 102 static int mmio_74xx_gpio_probe(struct platform_device *pdev) 103 { 104 struct mmio_74xx_gpio_priv *priv; 105 void __iomem *dat; 106 int err; 107 108 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 109 if (!priv) 110 return -ENOMEM; 111 112 priv->flags = (uintptr_t)of_device_get_match_data(&pdev->dev); 113 114 dat = devm_platform_ioremap_resource(pdev, 0); 115 if (IS_ERR(dat)) 116 return PTR_ERR(dat); 117 118 err = bgpio_init(&priv->gc, &pdev->dev, 119 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8), 120 dat, NULL, NULL, NULL, NULL, 0); 121 if (err) 122 return err; 123 124 priv->gc.direction_input = mmio_74xx_dir_in; 125 priv->gc.direction_output = mmio_74xx_dir_out; 126 priv->gc.get_direction = mmio_74xx_get_direction; 127 priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags); 128 priv->gc.owner = THIS_MODULE; 129 130 platform_set_drvdata(pdev, priv); 131 132 return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv); 133 } 134 135 static struct platform_driver mmio_74xx_gpio_driver = { 136 .driver = { 137 .name = "74xx-mmio-gpio", 138 .of_match_table = mmio_74xx_gpio_ids, 139 }, 140 .probe = mmio_74xx_gpio_probe, 141 }; 142 module_platform_driver(mmio_74xx_gpio_driver); 143 144 MODULE_LICENSE("GPL"); 145 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); 146 MODULE_DESCRIPTION("74xx MMIO GPIO driver"); 147