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/module.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_gpio.h>
  21 #include <linux/pinctrl/consumer.h>
  22 #include <linux/delay.h>
  23 #include <linux/timer.h>
  24 #include <linux/bitops.h>
  25 #include <linux/gpio/driver.h>
  26
  27 #define GPIO_DATA_OUT           0x00
  28 #define GPIO_DATA_IN            0x04
  29 #define GPIO_PIN_DIRECTION      0x08
  30
  31 static int moxart_gpio_probe(struct platform_device *pdev)
  32 {
  33         struct device *dev = &pdev->dev;
  34         struct resource *res;
  35         struct gpio_chip *gc;
  36         void __iomem *base;
  37         int ret;
  38
  39         gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
  40         if (!gc)
  41                 return -ENOMEM;
  42
  43         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  44         base = devm_ioremap_resource(dev, res);
  45         if (IS_ERR(base))
  46                 return PTR_ERR(base);
  47
  48         ret = bgpio_init(gc, dev, 4, base + GPIO_DATA_IN,
  49                          base + GPIO_DATA_OUT, NULL,
  50                          base + GPIO_PIN_DIRECTION, NULL,
  51                          BGPIOF_READ_OUTPUT_REG_SET);
  52         if (ret) {
  53                 dev_err(&pdev->dev, "bgpio_init failed\n");
  54                 return ret;
  55         }
  56
  57         gc->label = "moxart-gpio";
  58         gc->request = gpiochip_generic_request;
  59         gc->free = gpiochip_generic_free;
  60         gc->bgpio_data = gc->read_reg(gc->reg_set);
  61         gc->base = 0;
  62         gc->ngpio = 32;
  63         gc->parent = dev;
  64         gc->owner = THIS_MODULE;
  65
  66         ret = gpiochip_add_data(gc, NULL);
  67         if (ret) {
  68                 dev_err(dev, "%s: gpiochip_add failed\n",
  69                         dev->of_node->full_name);
  70                 return ret;
  71         }
  72
  73         return ret;
  74 }
  75
  76 static const struct of_device_id moxart_gpio_match[] = {
  77         { .compatible = "moxa,moxart-gpio" },
  78         { }
  79 };
  80
  81 static struct platform_driver moxart_gpio_driver = {
  82         .driver = {
  83                 .name           = "moxart-gpio",
  84                 .of_match_table = moxart_gpio_match,
  85         },
  86         .probe  = moxart_gpio_probe,
  87 };
  88 module_platform_driver(moxart_gpio_driver);
  89
  90 MODULE_DESCRIPTION("MOXART GPIO chip driver");
  91 MODULE_LICENSE("GPL");
  92 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");