drivers/gpio/gpio-74xx-mmio.c

   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");