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
  32 static int moxart_gpio_request(struct gpio_chip *chip, unsigned offset)
  33 {
  34         return pinctrl_request_gpio(offset);
  35 }
  36
  37 static void moxart_gpio_free(struct gpio_chip *chip, unsigned offset)
  38 {
  39         pinctrl_free_gpio(offset);
  40 }
  41
  42 static 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
  53 static 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
  98 static const struct of_device_id moxart_gpio_match[] = {
  99         { .compatible = "moxa,moxart-gpio" },
 100         { }
 101 };
 102
 103 static 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 };
 110 module_platform_driver(moxart_gpio_driver);
 111
 112 MODULE_DESCRIPTION("MOXART GPIO chip driver");
 113 MODULE_LICENSE("GPL");
 114 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");