gpio-74xx-mmio.c
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/*
* 74xx MMIO GPIO driver
*
* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/basic_mmio_gpio.h>
#include <linux/platform_device.h>
#define MMIO_74XX_DIR_IN (0 << 8)
#define MMIO_74XX_DIR_OUT (1 << 8)
#define MMIO_74XX_BIT_CNT(x) ((x) & 0xff)
struct mmio_74xx_gpio_priv {
struct bgpio_chip bgc;
unsigned flags;
};
static const struct of_device_id mmio_74xx_gpio_ids[] = {
{
.compatible = "ti,741g125",
.data = (const void *)(MMIO_74XX_DIR_IN | 1),
},
{
.compatible = "ti,742g125",
.data = (const void *)(MMIO_74XX_DIR_IN | 2),
},
{
.compatible = "ti,74125",
.data = (const void *)(MMIO_74XX_DIR_IN | 4),
},
{
.compatible = "ti,74365",
.data = (const void *)(MMIO_74XX_DIR_IN | 6),
},
{
.compatible = "ti,74244",
.data = (const void *)(MMIO_74XX_DIR_IN | 8),
},
{
.compatible = "ti,741624",
.data = (const void *)(MMIO_74XX_DIR_IN | 16),
},
{
.compatible = "ti,741g74",
.data = (const void *)(MMIO_74XX_DIR_OUT | 1),
},
{
.compatible = "ti,7474",
.data = (const void *)(MMIO_74XX_DIR_OUT | 2),
},
{
.compatible = "ti,74175",
.data = (const void *)(MMIO_74XX_DIR_OUT | 4),
},
{
.compatible = "ti,74174",
.data = (const void *)(MMIO_74XX_DIR_OUT | 6),
},
{
.compatible = "ti,74273",
.data = (const void *)(MMIO_74XX_DIR_OUT | 8),
},
{
.compatible = "ti,7416374",
.data = (const void *)(MMIO_74XX_DIR_OUT | 16),
},
{ }
};
MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
static inline struct mmio_74xx_gpio_priv *to_74xx_gpio(struct gpio_chip *gc)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
return container_of(bgc, struct mmio_74xx_gpio_priv, bgc);
}
static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
{
struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
return (priv->flags & MMIO_74XX_DIR_OUT) ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
}
static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
}
static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
if (priv->flags & MMIO_74XX_DIR_OUT) {
gc->set(gc, gpio, val);
return 0;
}
return -ENOTSUPP;
}
static int mmio_74xx_gpio_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id;
struct mmio_74xx_gpio_priv *priv;
struct resource *res;
void __iomem *dat;
int err;
of_id = of_match_device(mmio_74xx_gpio_ids, &pdev->dev);
if (!of_id)
return -ENODEV;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dat = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dat))
return PTR_ERR(dat);
priv->flags = (uintptr_t) of_id->data;
err = bgpio_init(&priv->bgc, &pdev->dev,
DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
dat, NULL, NULL, NULL, NULL, 0);
if (err)
return err;
priv->bgc.gc.direction_input = mmio_74xx_dir_in;
priv->bgc.gc.direction_output = mmio_74xx_dir_out;
priv->bgc.gc.get_direction = mmio_74xx_get_direction;
priv->bgc.gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
priv->bgc.gc.owner = THIS_MODULE;
platform_set_drvdata(pdev, priv);
return gpiochip_add(&priv->bgc.gc);
}
static int mmio_74xx_gpio_remove(struct platform_device *pdev)
{
struct mmio_74xx_gpio_priv *priv = platform_get_drvdata(pdev);
return bgpio_remove(&priv->bgc);
}
static struct platform_driver mmio_74xx_gpio_driver = {
.driver = {
.name = "74xx-mmio-gpio",
.of_match_table = mmio_74xx_gpio_ids,
},
.probe = mmio_74xx_gpio_probe,
.remove = mmio_74xx_gpio_remove,
};
module_platform_driver(mmio_74xx_gpio_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("74xx MMIO GPIO driver");