kernel_drivers_examples/debug/platform_driver_test/skeleton_ss.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/delay.h>

#include "skeleton_ss.h"

/* cat egpios_debug */
static ssize_t egpios_debug_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	int size = 0;
	struct skleton_chip *chip;

	chip = dev_get_drvdata(dev);

	size = sprintf(buf, "%s value is %d\n", chip->pd[chip->pin_name_index]->name, gpio_get_value(chip->pd[chip->pin_name_index]->gpio_pin));
	return size;
}

/* echo <pin_index> <val> > egpios_debug */
static ssize_t egpios_debug_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct skleton_chip *chip;

	chip = dev_get_drvdata(dev);

	sscanf(buf, "%d %d", &chip->pin_name_index, &chip->value);
	gpio_set_value(chip->pd[chip->pin_name_index]->gpio_pin, chip->value);
	return count;
}

static DEVICE_ATTR(egpios_debug, S_IRUGO | S_IWUSR, egpios_debug_show, egpios_debug_store);

static struct attribute *egpios_attrs[] = {
	&dev_attr_egpios_debug.attr,
	NULL,
};

static const struct attribute_group egpios_attr_group = {
	.attrs = egpios_attrs,
};

static int skeleton_ss_probe(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	int i;
	enum of_gpio_flags flag;
	struct skleton_chip *chip;

	int gpio_nr;
	int ret;

	gpio_nr = sizeof(dts_name) / sizeof(dts_name[0]);

	/* alloc for chip point */
	chip = devm_kzalloc(&pdev->dev, sizeof(struct skleton_chip), GFP_KERNEL);
	if (!chip)
	{
		printk("no memory\n");
		ret = -ENOMEM;
	}

	/* alloc memory for array head */
	chip->pd = devm_kzalloc(&pdev->dev, sizeof(struct pin_desc *) * gpio_nr, GFP_KERNEL);
	if (!chip->pd)
	{
		printk("no memory\n");
		ret = -ENOMEM;
	}

	/* alloc memory for every point in the array */
	for (i = 0; i < gpio_nr; i++)
	{
		chip->pd[i] = devm_kzalloc(&pdev->dev, sizeof(struct pin_desc), GFP_KERNEL);
		if (!chip->pd[i])
		{
			printk("no memory\n");
			ret = -ENOMEM;
		}
	}

	/* set pdata */
	dev_set_drvdata(&pdev->dev, (void *)chip);

	/* make the pin desc names */
	for (i = 0; i < gpio_nr; i++)
		strcpy(chip->pd[i]->name, dts_name[i]);

	/* make all pins active */
	for (i = 0; i < gpio_nr; i++)
	{
		chip->pd[i]->gpio_pin = of_get_named_gpio_flags(node, chip->pd[i]->name, 0, &flag);

		/* ROCKCHIP gpio active high and low is reverse */
		chip->pd[i]->gpio_active_flag = !flag;

		ret = devm_gpio_request(&pdev->dev, chip->pd[i]->gpio_pin, chip->pd[i]->name);
		if (ret)
		{
			printk("%s error\n", chip->pd[i]->name);
		}
		else
		{
			ret = gpio_direction_output(chip->pd[i]->gpio_pin, chip->pd[i]->gpio_active_flag);
#ifdef READ_VALUE_BACK
			printk("%s[%d]\n", chip->pd[i]->name, gpio_get_value(chip->pd[i]->gpio_pin));
#endif
		}
	}

	/* sysfs */
	ret = sysfs_create_group(&pdev->dev.kobj, &egpios_attr_group);
	if (ret)
	{
		printk("failed to create sysfs device attributes\n");
		return -1;
	}
	return 0;
}

static int skeleton_ss_remove(struct platform_device *pdev)
{
	sysfs_remove_group(&pdev->dev.kobj, &egpios_attr_group);
	printk("%s, %d\n", __FUNCTION__, __LINE__);

	return 0;
}

static const struct of_device_id skeleton_ss_dt_ids[] = {
	{.compatible = "skeleton, compatible",},
	{},
};

int skeleton_ss_suspend(struct platform_device *pdev, pm_message_t state)
{
	printk("%s, %d\n", __FUNCTION__, __LINE__);
	return 0;
}

int skeleton_ss_resume(struct platform_device *pdev)
{
	int i;
	int gpio_nr;
	struct skleton_chip *chip;

	gpio_nr = sizeof(dts_name) / sizeof(dts_name[0]);
	chip = dev_get_drvdata(&pdev->dev);

	printk("%s, %d\n", __FUNCTION__, __LINE__);

	/* active all */
	for (i = 0; i < gpio_nr; i++)
		gpio_set_value(chip->pd[i]->gpio_pin, chip->pd[i]->gpio_active_flag);

	return 0;
}

static struct platform_driver skeleton_ss = {
	.driver		= {
		.name	= "skeleton example",
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(skeleton_ss_dt_ids),
	},
	.probe		= skeleton_ss_probe,
	.remove 	= skeleton_ss_remove,
    .suspend    = skeleton_ss_suspend,
    .resume     = skeleton_ss_resume,
};

module_platform_driver(skeleton_ss);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("zeroway <M_O_Bz@163.com>");
MODULE_DESCRIPTION("skeleton");