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

   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/gpio.h>
  14 #include <linux/module.h>
  15 #include <linux/of_device.h>
  16 #include <linux/basic_mmio_gpio.h>
  17 #include <linux/platform_device.h>
  18
  19 #define MMIO_74XX_DIR_IN        (0 << 8)
  20 #define MMIO_74XX_DIR_OUT       (1 << 8)
  21 #define MMIO_74XX_BIT_CNT(x)    ((x) & 0xff)
  22
  23 struct mmio_74xx_gpio_priv {
  24         struct bgpio_chip       bgc;
  25         unsigned                flags;
  26 };
  27
  28 static const struct of_device_id mmio_74xx_gpio_ids[] = {
  29         {
  30                 .compatible     = "ti,741g125",
  31                 .data           = (const void *)(MMIO_74XX_DIR_IN | 1),
  32         },
  33         {
  34                 .compatible     = "ti,742g125",
  35                 .data           = (const void *)(MMIO_74XX_DIR_IN | 2),
  36         },
  37         {
  38                 .compatible     = "ti,74125",
  39                 .data           = (const void *)(MMIO_74XX_DIR_IN | 4),
  40         },
  41         {
  42                 .compatible     = "ti,74365",
  43                 .data           = (const void *)(MMIO_74XX_DIR_IN | 6),
  44         },
  45         {
  46                 .compatible     = "ti,74244",
  47                 .data           = (const void *)(MMIO_74XX_DIR_IN | 8),
  48         },
  49         {
  50                 .compatible     = "ti,741624",
  51                 .data           = (const void *)(MMIO_74XX_DIR_IN | 16),
  52         },
  53         {
  54                 .compatible     = "ti,741g74",
  55                 .data           = (const void *)(MMIO_74XX_DIR_OUT | 1),
  56         },
  57         {
  58                 .compatible     = "ti,7474",
  59                 .data           = (const void *)(MMIO_74XX_DIR_OUT | 2),
  60         },
  61         {
  62                 .compatible     = "ti,74175",
  63                 .data           = (const void *)(MMIO_74XX_DIR_OUT | 4),
  64         },
  65         {
  66                 .compatible     = "ti,74174",
  67                 .data           = (const void *)(MMIO_74XX_DIR_OUT | 6),
  68         },
  69         {
  70                 .compatible     = "ti,74273",
  71                 .data           = (const void *)(MMIO_74XX_DIR_OUT | 8),
  72         },
  73         {
  74                 .compatible     = "ti,7416374",
  75                 .data           = (const void *)(MMIO_74XX_DIR_OUT | 16),
  76         },
  77         { }
  78 };
  79 MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
  80
  81 static inline struct mmio_74xx_gpio_priv *to_74xx_gpio(struct gpio_chip *gc)
  82 {
  83         struct bgpio_chip *bgc = to_bgpio_chip(gc);
  84
  85         return container_of(bgc, struct mmio_74xx_gpio_priv, bgc);
  86 }
  87
  88 static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
  89 {
  90         struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
  91
  92         return (priv->flags & MMIO_74XX_DIR_OUT) ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
  93 }
  94
  95 static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
  96 {
  97         struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
  98
  99         return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
 100 }
 101
 102 static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 103 {
 104         struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
 105
 106         if (priv->flags & MMIO_74XX_DIR_OUT) {
 107                 gc->set(gc, gpio, val);
 108                 return 0;
 109         }
 110
 111         return -ENOTSUPP;
 112 }
 113
 114 static int mmio_74xx_gpio_probe(struct platform_device *pdev)
 115 {
 116         const struct of_device_id *of_id =
 117                 of_match_device(mmio_74xx_gpio_ids, &pdev->dev);
 118         struct mmio_74xx_gpio_priv *priv;
 119         struct resource *res;
 120         void __iomem *dat;
 121         int err;
 122
 123         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 124         if (!priv)
 125                 return -ENOMEM;
 126
 127         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 128         dat = devm_ioremap_resource(&pdev->dev, res);
 129         if (IS_ERR(dat))
 130                 return PTR_ERR(dat);
 131
 132         priv->flags = (uintptr_t) of_id->data;
 133
 134         err = bgpio_init(&priv->bgc, &pdev->dev,
 135                          DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
 136                          dat, NULL, NULL, NULL, NULL, 0);
 137         if (err)
 138                 return err;
 139
 140         priv->bgc.gc.direction_input = mmio_74xx_dir_in;
 141         priv->bgc.gc.direction_output = mmio_74xx_dir_out;
 142         priv->bgc.gc.get_direction = mmio_74xx_get_direction;
 143         priv->bgc.gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
 144         priv->bgc.gc.owner = THIS_MODULE;
 145
 146         platform_set_drvdata(pdev, priv);
 147
 148         return gpiochip_add(&priv->bgc.gc);
 149 }
 150
 151 static int mmio_74xx_gpio_remove(struct platform_device *pdev)
 152 {
 153         struct mmio_74xx_gpio_priv *priv = platform_get_drvdata(pdev);
 154
 155         return bgpio_remove(&priv->bgc);
 156 }
 157
 158 static struct platform_driver mmio_74xx_gpio_driver = {
 159         .driver = {
 160                 .name           = "74xx-mmio-gpio",
 161                 .of_match_table = mmio_74xx_gpio_ids,
 162         },
 163         .probe  = mmio_74xx_gpio_probe,
 164         .remove = mmio_74xx_gpio_remove,
 165 };
 166 module_platform_driver(mmio_74xx_gpio_driver);
 167
 168 MODULE_LICENSE("GPL");
 169 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
 170 MODULE_DESCRIPTION("74xx MMIO GPIO driver");