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_probe(struct platform_device *pdev)
  43 {
  44         struct device *dev = &pdev->dev;
  45         struct resource *res;
  46         struct bgpio_chip *bgc;
  47         void __iomem *base;
  48         int ret;
  49
  50         bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL);
  51         if (!bgc)
  52                 return -ENOMEM;
  53
  54         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  55         base = devm_ioremap_resource(dev, res);
  56         if (IS_ERR(base))
  57                 return PTR_ERR(base);
  58
  59         ret = bgpio_init(bgc, dev, 4, base + GPIO_DATA_IN,
  60                          base + GPIO_DATA_OUT, NULL,
  61                          base + GPIO_PIN_DIRECTION, NULL,
  62                          BGPIOF_READ_OUTPUT_REG_SET);
  63         if (ret) {
  64                 dev_err(&pdev->dev, "bgpio_init failed\n");
  65                 return ret;
  66         }
  67
  68         bgc->gc.label = "moxart-gpio";
  69         bgc->gc.request = moxart_gpio_request;
  70         bgc->gc.free = moxart_gpio_free;
  71         bgc->data = bgc->read_reg(bgc->reg_set);
  72         bgc->gc.base = 0;
  73         bgc->gc.ngpio = 32;
  74         bgc->gc.dev = dev;
  75         bgc->gc.owner = THIS_MODULE;
  76
  77         ret = gpiochip_add(&bgc->gc);
  78         if (ret) {
  79                 dev_err(dev, "%s: gpiochip_add failed\n",
  80                         dev->of_node->full_name);
  81                 return ret;
  82         }
  83
  84         return ret;
  85 }
  86
  87 static const struct of_device_id moxart_gpio_match[] = {
  88         { .compatible = "moxa,moxart-gpio" },
  89         { }
  90 };
  91
  92 static struct platform_driver moxart_gpio_driver = {
  93         .driver = {
  94                 .name           = "moxart-gpio",
  95                 .of_match_table = moxart_gpio_match,
  96         },
  97         .probe  = moxart_gpio_probe,
  98 };
  99 module_platform_driver(moxart_gpio_driver);
 100
 101 MODULE_DESCRIPTION("MOXART GPIO chip driver");
 102 MODULE_LICENSE("GPL");
 103 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");