vr41xx_giu.c

来自「linux 内核源代码」· C语言 代码 · 共 679 行 · 第 1/2 页

	unsigned long flags;

	if (pin >= giu_nr_pins)
		return -EINVAL;

	if (pin < 16) {
		offset = GIUPIODL;
		mask = (uint16_t)1 << pin;
	} else if (pin < 32) {
		offset = GIUPIODH;
		mask = (uint16_t)1 << (pin - 16);
	} else if (pin < 48) {
		offset = GIUPODATL;
		mask = (uint16_t)1 << (pin - 32);
	} else {
		offset = GIUPODATH;
		mask = (uint16_t)1 << (pin - 48);
	}

	spin_lock_irqsave(&giu_lock, flags);

	reg = giu_read(offset);
	if (data == GPIO_DATA_HIGH)
		reg |= mask;
	else
		reg &= ~mask;
	giu_write(offset, reg);

	spin_unlock_irqrestore(&giu_lock, flags);

	return 0;
}
EXPORT_SYMBOL_GPL(vr41xx_gpio_set_pin);

int vr41xx_gpio_set_direction(unsigned int pin, gpio_direction_t dir)
{
	uint16_t offset, mask, reg;
	unsigned long flags;

	if (pin >= giu_nr_pins)
		return -EINVAL;

	if (pin < 16) {
		offset = GIUIOSELL;
		mask = (uint16_t)1 << pin;
	} else if (pin < 32) {
		offset = GIUIOSELH;
		mask = (uint16_t)1 << (pin - 16);
	} else {
		if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
			offset = GIUPODATEN;
			mask = (uint16_t)1 << (pin - 32);
		} else {
			switch (pin) {
			case 48:
				offset = GIUPODATH;
				mask = PIOEN0;
				break;
			case 49:
				offset = GIUPODATH;
				mask = PIOEN1;
				break;
			default:
				return -EINVAL;
			}
		}
	}

	spin_lock_irqsave(&giu_lock, flags);

	reg = giu_read(offset);
	if (dir == GPIO_OUTPUT)
		reg |= mask;
	else
		reg &= ~mask;
	giu_write(offset, reg);

	spin_unlock_irqrestore(&giu_lock, flags);

	return 0;
}
EXPORT_SYMBOL_GPL(vr41xx_gpio_set_direction);

int vr41xx_gpio_pullupdown(unsigned int pin, gpio_pull_t pull)
{
	uint16_t reg, mask;
	unsigned long flags;

	if ((giu_flags & GPIO_HAS_PULLUPDOWN_IO) != GPIO_HAS_PULLUPDOWN_IO)
		return -EPERM;

	if (pin >= 15)
		return -EINVAL;

	mask = (uint16_t)1 << pin;

	spin_lock_irqsave(&giu_lock, flags);

	if (pull == GPIO_PULL_UP || pull == GPIO_PULL_DOWN) {
		reg = giu_read(GIUTERMUPDN);
		if (pull == GPIO_PULL_UP)
			reg |= mask;
		else
			reg &= ~mask;
		giu_write(GIUTERMUPDN, reg);

		reg = giu_read(GIUUSEUPDN);
		reg |= mask;
		giu_write(GIUUSEUPDN, reg);
	} else {
		reg = giu_read(GIUUSEUPDN);
		reg &= ~mask;
		giu_write(GIUUSEUPDN, reg);
	}

	spin_unlock_irqrestore(&giu_lock, flags);

	return 0;
}
EXPORT_SYMBOL_GPL(vr41xx_gpio_pullupdown);

static ssize_t gpio_read(struct file *file, char __user *buf, size_t len,
                         loff_t *ppos)
{
	unsigned int pin;
	char value = '0';

	pin = iminor(file->f_path.dentry->d_inode);
	if (pin >= giu_nr_pins)
		return -EBADF;

	if (vr41xx_gpio_get_pin(pin) == GPIO_DATA_HIGH)
		value = '1';

	if (len <= 0)
		return -EFAULT;

	if (put_user(value, buf))
		return -EFAULT;

	return 1;
}

static ssize_t gpio_write(struct file *file, const char __user *data,
                          size_t len, loff_t *ppos)
{
	unsigned int pin;
	size_t i;
	char c;
	int retval = 0;

	pin = iminor(file->f_path.dentry->d_inode);
	if (pin >= giu_nr_pins)
		return -EBADF;

	for (i = 0; i < len; i++) {
		if (get_user(c, data + i))
			return -EFAULT;

		switch (c) {
		case '0':
			retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_LOW);
			break;
		case '1':
			retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_HIGH);
			break;
		case 'D':
			printk(KERN_INFO "GPIO%d: pull down\n", pin);
			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DOWN);
			break;
		case 'd':
			printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
			break;
		case 'I':
			printk(KERN_INFO "GPIO%d: input\n", pin);
			retval = vr41xx_gpio_set_direction(pin, GPIO_INPUT);
			break;
		case 'O':
			printk(KERN_INFO "GPIO%d: output\n", pin);
			retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT);
			break;
		case 'o':
			printk(KERN_INFO "GPIO%d: output disable\n", pin);
			retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT_DISABLE);
			break;
		case 'P':
			printk(KERN_INFO "GPIO%d: pull up\n", pin);
			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_UP);
			break;
		case 'p':
			printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
			break;
		default:
			break;
		}

		if (retval < 0)
			break;
	}

	return i;
}

static int gpio_open(struct inode *inode, struct file *file)
{
	unsigned int pin;

	pin = iminor(inode);
	if (pin >= giu_nr_pins)
		return -EBADF;

	return nonseekable_open(inode, file);
}

static int gpio_release(struct inode *inode, struct file *file)
{
	unsigned int pin;

	pin = iminor(inode);
	if (pin >= giu_nr_pins)
		return -EBADF;

	return 0;
}

static const struct file_operations gpio_fops = {
	.owner		= THIS_MODULE,
	.read		= gpio_read,
	.write		= gpio_write,
	.open		= gpio_open,
	.release	= gpio_release,
};

static int __devinit giu_probe(struct platform_device *dev)
{
	struct resource *res;
	unsigned int trigger, i, pin;
	struct irq_chip *chip;
	int irq, retval;

	switch (dev->id) {
	case GPIO_50PINS_PULLUPDOWN:
		giu_flags = GPIO_HAS_PULLUPDOWN_IO;
		giu_nr_pins = 50;
		break;
	case GPIO_36PINS:
		giu_nr_pins = 36;
		break;
	case GPIO_48PINS_EDGE_SELECT:
		giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
		giu_nr_pins = 48;
		break;
	default:
		printk(KERN_ERR "GIU: unknown ID %d\n", dev->id);
		return -ENODEV;
	}

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res)
		return -EBUSY;

	giu_base = ioremap(res->start, res->end - res->start + 1);
	if (!giu_base)
		return -ENOMEM;

	retval = register_chrdev(major, "GIU", &gpio_fops);
	if (retval < 0) {
		iounmap(giu_base);
		giu_base = NULL;
		return retval;
	}

	if (major == 0) {
		major = retval;
		printk(KERN_INFO "GIU: major number %d\n", major);
	}

	spin_lock_init(&giu_lock);

	giu_write(GIUINTENL, 0);
	giu_write(GIUINTENH, 0);

	trigger = giu_read(GIUINTTYPH) << 16;
	trigger |= giu_read(GIUINTTYPL);
	for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
		pin = GPIO_PIN_OF_IRQ(i);
		if (pin < GIUINT_HIGH_OFFSET)
			chip = &giuint_low_irq_chip;
		else
			chip = &giuint_high_irq_chip;

		if (trigger & (1 << pin))
			set_irq_chip_and_handler(i, chip, handle_edge_irq);
		else
			set_irq_chip_and_handler(i, chip, handle_level_irq);

	}

	irq = platform_get_irq(dev, 0);
	if (irq < 0 || irq >= NR_IRQS)
		return -EBUSY;

	return cascade_irq(irq, giu_get_irq);
}

static int __devexit giu_remove(struct platform_device *dev)
{
	if (giu_base) {
		iounmap(giu_base);
		giu_base = NULL;
	}

	return 0;
}

static struct platform_driver giu_device_driver = {
	.probe		= giu_probe,
	.remove		= __devexit_p(giu_remove),
	.driver		= {
		.name	= "GIU",
		.owner	= THIS_MODULE,
	},
};

static int __init vr41xx_giu_init(void)
{
	return platform_driver_register(&giu_device_driver);
}

static void __exit vr41xx_giu_exit(void)
{
	platform_driver_unregister(&giu_device_driver);
}

module_init(vr41xx_giu_init);
module_exit(vr41xx_giu_exit);