LXR linux/drivers/gpio/gpio-moxart.c

   1/*
   2 * MOXA ART SoCs GPIO driver.
   3 *
   4 * Copyright (C) 2013 Jonas Jensen
   5 *
   6 * Jonas Jensen <jonas.jensen@gmail.com>
   7 *
   8 * This file is licensed under the terms of the GNU General Public
   9 * License version 2.  This program is licensed "as is" without any
  10 * warranty of any kind, whether express or implied.
  11 */
  12
  13#include <linux/err.h>
  14#include <linux/init.h>
  15#include <linux/irq.h>
  16#include <linux/io.h>
  17#include <linux/gpio.h>
  18#include <linux/platform_device.h>
  19#include <linux/module.h>
  20#include <linux/of_address.h>
  21#include <linux/of_gpio.h>
  22#include <linux/pinctrl/consumer.h>
  23#include <linux/delay.h>
  24#include <linux/timer.h>
  25#include <linux/bitops.h>
  26#include <linux/basic_mmio_gpio.h>
  27
  28#define GPIO_DATA_OUT           0x00
  29#define GPIO_DATA_IN            0x04
  30#define GPIO_PIN_DIRECTION      0x08
  31
  32static int moxart_gpio_request(struct gpio_chip *chip, unsigned offset)
  33{
  34        return pinctrl_request_gpio(offset);
  35}
  36
  37static void moxart_gpio_free(struct gpio_chip *chip, unsigned offset)
  38{
  39        pinctrl_free_gpio(offset);
  40}
  41
  42static int moxart_gpio_get(struct gpio_chip *chip, unsigned offset)
  43{
  44        struct bgpio_chip *bgc = to_bgpio_chip(chip);
  45        u32 ret = bgc->read_reg(bgc->reg_dir);
  46
  47        if (ret & BIT(offset))
  48                return !!(bgc->read_reg(bgc->reg_set) & BIT(offset));
  49        else
  50                return !!(bgc->read_reg(bgc->reg_dat) & BIT(offset));
  51}
  52
  53static int moxart_gpio_probe(struct platform_device *pdev)
  54{
  55        struct device *dev = &pdev->dev;
  56        struct resource *res;
  57        struct bgpio_chip *bgc;
  58        void __iomem *base;
  59        int ret;
  60
  61        bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL);
  62        if (!bgc)
  63                return -ENOMEM;
  64
  65        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  66        base = devm_ioremap_resource(dev, res);
  67        if (IS_ERR(base))
  68                return PTR_ERR(base);
  69
  70        ret = bgpio_init(bgc, dev, 4, base + GPIO_DATA_IN,
  71                    base + GPIO_DATA_OUT, NULL,
  72                    base + GPIO_PIN_DIRECTION, NULL, 0);
  73        if (ret) {
  74                dev_err(&pdev->dev, "bgpio_init failed\n");
  75                return ret;
  76        }
  77
  78        bgc->gc.label = "moxart-gpio";
  79        bgc->gc.request = moxart_gpio_request;
  80        bgc->gc.free = moxart_gpio_free;
  81        bgc->gc.get = moxart_gpio_get;
  82        bgc->data = bgc->read_reg(bgc->reg_set);
  83        bgc->gc.base = 0;
  84        bgc->gc.ngpio = 32;
  85        bgc->gc.dev = dev;
  86        bgc->gc.owner = THIS_MODULE;
  87
  88        ret = gpiochip_add(&bgc->gc);
  89        if (ret) {
  90                dev_err(dev, "%s: gpiochip_add failed\n",
  91                        dev->of_node->full_name);
  92                return ret;
  93        }
  94
  95        return ret;
  96}
  97
  98static const struct of_device_id moxart_gpio_match[] = {
  99        { .compatible = "moxa,moxart-gpio" },
 100        { }
 101};
 102
 103static struct platform_driver moxart_gpio_driver = {
 104        .driver = {
 105                .name           = "moxart-gpio",
 106                .of_match_table = moxart_gpio_match,
 107        },
 108        .probe  = moxart_gpio_probe,
 109};
 110module_platform_driver(moxart_gpio_driver);
 111
 112MODULE_DESCRIPTION("MOXART GPIO chip driver");
 113MODULE_LICENSE("GPL");
 114MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
 115