LXR linux/drivers/gpio/gpio-ts4800.c

   1/*
   2 * GPIO driver for the TS-4800 board
   3 *
   4 * Copyright (c) 2016 - Savoir-faire Linux
   5 *
   6 * This file is licensed under the terms of the GNU General Public
   7 * License version 2. This program is licensed "as is" without any
   8 * warranty of any kind, whether express or implied.
   9 */
  10
  11#include <linux/gpio/driver.h>
  12#include <linux/module.h>
  13#include <linux/of_address.h>
  14#include <linux/of_device.h>
  15#include <linux/platform_device.h>
  16
  17#define DEFAULT_PIN_NUMBER      16
  18#define INPUT_REG_OFFSET        0x00
  19#define OUTPUT_REG_OFFSET       0x02
  20#define DIRECTION_REG_OFFSET    0x04
  21
  22static int ts4800_gpio_probe(struct platform_device *pdev)
  23{
  24        struct device_node *node;
  25        struct gpio_chip *chip;
  26        void __iomem *base_addr;
  27        int retval;
  28        u32 ngpios;
  29
  30        chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL);
  31        if (!chip)
  32                return -ENOMEM;
  33
  34        base_addr = devm_platform_ioremap_resource(pdev, 0);
  35        if (IS_ERR(base_addr))
  36                return PTR_ERR(base_addr);
  37
  38        node = pdev->dev.of_node;
  39        if (!node)
  40                return -EINVAL;
  41
  42        retval = of_property_read_u32(node, "ngpios", &ngpios);
  43        if (retval == -EINVAL)
  44                ngpios = DEFAULT_PIN_NUMBER;
  45        else if (retval)
  46                return retval;
  47
  48        retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET,
  49                            base_addr + OUTPUT_REG_OFFSET, NULL,
  50                            base_addr + DIRECTION_REG_OFFSET, NULL, 0);
  51        if (retval) {
  52                dev_err(&pdev->dev, "bgpio_init failed\n");
  53                return retval;
  54        }
  55
  56        chip->ngpio = ngpios;
  57
  58        platform_set_drvdata(pdev, chip);
  59
  60        return devm_gpiochip_add_data(&pdev->dev, chip, NULL);
  61}
  62
  63static const struct of_device_id ts4800_gpio_of_match[] = {
  64        { .compatible = "technologic,ts4800-gpio", },
  65        {},
  66};
  67MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match);
  68
  69static struct platform_driver ts4800_gpio_driver = {
  70        .driver = {
  71                   .name = "ts4800-gpio",
  72                   .of_match_table = ts4800_gpio_of_match,
  73                   },
  74        .probe = ts4800_gpio_probe,
  75};
  76
  77module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe);
  78
  79MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>");
  80MODULE_DESCRIPTION("TS4800 FPGA GPIO driver");
  81MODULE_LICENSE("GPL v2");
  82