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