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/platform_device.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_gpio.h>
  20 #include <linux/pinctrl/consumer.h>
  21 #include <linux/delay.h>
  22 #include <linux/timer.h>
  23 #include <linux/bitops.h>
  24 #include <linux/gpio/driver.h>
  25
  26 #define GPIO_DATA_OUT           0x00
  27 #define GPIO_DATA_IN            0x04
  28 #define GPIO_PIN_DIRECTION      0x08
  29
  30 static int moxart_gpio_probe(struct platform_device *pdev)
  31 {
  32         struct device *dev = &pdev->dev;
  33         struct resource *res;
  34         struct gpio_chip *gc;
  35         void __iomem *base;
  36         int ret;
  37
  38         gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
  39         if (!gc)
  40                 return -ENOMEM;
  41
  42         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  43         base = devm_ioremap_resource(dev, res);
  44         if (IS_ERR(base))
  45                 return PTR_ERR(base);
  46
  47         ret = bgpio_init(gc, dev, 4, base + GPIO_DATA_IN,
  48                          base + GPIO_DATA_OUT, NULL,
  49                          base + GPIO_PIN_DIRECTION, NULL,
  50                          BGPIOF_READ_OUTPUT_REG_SET);
  51         if (ret) {
  52                 dev_err(&pdev->dev, "bgpio_init failed\n");
  53                 return ret;
  54         }
  55
  56         gc->label = "moxart-gpio";
  57         gc->request = gpiochip_generic_request;
  58         gc->free = gpiochip_generic_free;
  59         gc->base = 0;
  60         gc->owner = THIS_MODULE;
  61
  62         ret = devm_gpiochip_add_data(dev, gc, NULL);
  63         if (ret) {
  64                 dev_err(dev, "%s: gpiochip_add failed\n",
  65                         dev->of_node->full_name);
  66                 return ret;
  67         }
  68
  69         return ret;
  70 }
  71
  72 static const struct of_device_id moxart_gpio_match[] = {
  73         { .compatible = "moxa,moxart-gpio" },
  74         { }
  75 };
  76
  77 static struct platform_driver moxart_gpio_driver = {
  78         .driver = {
  79                 .name           = "moxart-gpio",
  80                 .of_match_table = moxart_gpio_match,
  81         },
  82         .probe  = moxart_gpio_probe,
  83 };
  84 builtin_platform_driver(moxart_gpio_driver);