drivers/gpio/gpio-loongson-64bit.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-loongson-64bit.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-loongson-64bit.c
Extension
.c
Size
15579 bytes
Lines
580
Domain
Driver Families
Bucket
drivers/gpio
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 loongson_gpio_chip_data {
	const char		*label;
	enum loongson_gpio_mode	mode;
	unsigned int		conf_offset;
	unsigned int		out_offset;
	unsigned int		in_offset;
	unsigned int		inten_offset;
	unsigned int		intpol_offset;
	unsigned int		intedge_offset;
	unsigned int		intclr_offset;
	unsigned int		intsts_offset;
	unsigned int		intdual_offset;
	unsigned int		intr_num;
	irq_flow_handler_t	irq_handler;
	const struct irq_chip	*girqchip;
};

struct loongson_gpio_chip {
	struct gpio_generic_chip chip;
	spinlock_t		lock;
	void __iomem		*reg_base;
	const struct loongson_gpio_chip_data *chip_data;
};

static inline struct loongson_gpio_chip *to_loongson_gpio_chip(struct gpio_chip *chip)
{
	return container_of(to_gpio_generic_chip(chip),
			    struct loongson_gpio_chip, chip);
}

static inline void loongson_commit_direction(struct loongson_gpio_chip *lgpio, unsigned int pin,
					     int input)
{
	u8 bval = input ? 1 : 0;

	writeb(bval, lgpio->reg_base + lgpio->chip_data->conf_offset + pin);
}

static void loongson_commit_level(struct loongson_gpio_chip *lgpio, unsigned int pin, int high)
{
	u8 bval = high ? 1 : 0;

	writeb(bval, lgpio->reg_base + lgpio->chip_data->out_offset + pin);
}

static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned int pin)
{
	unsigned long flags;
	struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip);

	spin_lock_irqsave(&lgpio->lock, flags);
	loongson_commit_direction(lgpio, pin, 1);
	spin_unlock_irqrestore(&lgpio->lock, flags);

	return 0;
}

static int loongson_gpio_direction_output(struct gpio_chip *chip, unsigned int pin, int value)
{
	unsigned long flags;
	struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip);

	spin_lock_irqsave(&lgpio->lock, flags);
	loongson_commit_level(lgpio, pin, value);
	loongson_commit_direction(lgpio, pin, 0);
	spin_unlock_irqrestore(&lgpio->lock, flags);

	return 0;
}

static int loongson_gpio_get(struct gpio_chip *chip, unsigned int pin)
{
	u8  bval;
	int val;
	struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip);

	bval = readb(lgpio->reg_base + lgpio->chip_data->in_offset + pin);
	val = bval & 1;

	return val;
}

static int loongson_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
{
	u8  bval;
	struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip);

	bval = readb(lgpio->reg_base + lgpio->chip_data->conf_offset + pin);
	if (bval & 1)
		return GPIO_LINE_DIRECTION_IN;

Annotation

Implementation Notes