drivers/gpio/gpio-timberdale.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-timberdale.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-timberdale.c
Extension
.c
Size
7213 bytes
Lines
296
Domain
Driver Families
Bucket
drivers/gpio
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct timbgpio {
	void __iomem		*membase;
	spinlock_t		lock; /* mutual exclusion */
	struct gpio_chip	gpio;
	int			irq_base;
	unsigned long		last_ier;
};

static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
	unsigned offset, bool enabled)
{
	struct timbgpio *tgpio = gpiochip_get_data(gpio);
	unsigned long flags;
	u32 reg;

	spin_lock_irqsave(&tgpio->lock, flags);
	reg = ioread32(tgpio->membase + offset);

	if (enabled)
		reg |= (1 << index);
	else
		reg &= ~(1 << index);

	iowrite32(reg, tgpio->membase + offset);
	spin_unlock_irqrestore(&tgpio->lock, flags);

	return 0;
}

static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
{
	return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
}

static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
{
	struct timbgpio *tgpio = gpiochip_get_data(gpio);
	u32 value;

	value = ioread32(tgpio->membase + TGPIOVAL);
	return (value & (1 << nr)) ? 1 : 0;
}

static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
						unsigned nr, int val)
{
	return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
}

static int timbgpio_gpio_set(struct gpio_chip *gpio, unsigned int nr, int val)
{
	return timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
}

static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
{
	struct timbgpio *tgpio = gpiochip_get_data(gpio);

	if (tgpio->irq_base <= 0)
		return -EINVAL;

	return tgpio->irq_base + offset;
}

/*
 * GPIO IRQ
 */
static void timbgpio_irq_disable(struct irq_data *d)
{
	struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
	int offset = d->irq - tgpio->irq_base;
	irq_hw_number_t hwirq = irqd_to_hwirq(d);
	unsigned long flags;

	spin_lock_irqsave(&tgpio->lock, flags);
	tgpio->last_ier &= ~(1UL << offset);
	iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
	spin_unlock_irqrestore(&tgpio->lock, flags);

	gpiochip_disable_irq(&tgpio->gpio, hwirq);
}

static void timbgpio_irq_enable(struct irq_data *d)
{
	struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
	int offset = d->irq - tgpio->irq_base;
	irq_hw_number_t hwirq = irqd_to_hwirq(d);
	unsigned long flags;

	gpiochip_enable_irq(&tgpio->gpio, hwirq);

Annotation

Implementation Notes