linux-imx

/*

 * GPIO driver for the TS-4800 board

 *

 * Copyright (c) 2016 - Savoir-faire Linux

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */

​

#include <linux/gpio/driver.h>

#include <linux/module.h>

#include <linux/of_address.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

​

#define DEFAULT_PIN_NUMBER      16

#define INPUT_REG_OFFSET        0x00

#define OUTPUT_REG_OFFSET       0x02

#define DIRECTION_REG_OFFSET    0x04

​

static int ts4800_gpio_probe(struct platform_device *pdev)

{

    struct device_node *node;

    struct gpio_chip *chip;

    struct resource *res;

    void __iomem *base_addr;

    int retval;

    u32 ngpios;

​

    chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL);

    if (!chip)

        return -ENOMEM;

​

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    base_addr = devm_ioremap_resource(&pdev->dev, res);

    if (IS_ERR(base_addr))

        return PTR_ERR(base_addr);

​

    node = pdev->dev.of_node;

    if (!node)

        return -EINVAL;

​

    retval = of_property_read_u32(node, "ngpios", &ngpios);

    if (retval == -EINVAL)

        ngpios = DEFAULT_PIN_NUMBER;

    else if (retval)

        return retval;

​

    retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET,

                base_addr + OUTPUT_REG_OFFSET, NULL,

                base_addr + DIRECTION_REG_OFFSET, NULL, 0);

    if (retval) {

        dev_err(&pdev->dev, "bgpio_init failed\n");

        return retval;

    }

​

    chip->ngpio = ngpios;

​

    platform_set_drvdata(pdev, chip);

​

    return devm_gpiochip_add_data(&pdev->dev, chip, NULL);

}