drivers/gpio/gpio-mxs.c

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

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-mxs.c
Extension
.c
Size
10098 bytes
Lines
373
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 mxs_gpio_port {
	void __iomem *base;
	int id;
	int irq;
	struct irq_domain *domain;
	struct gpio_generic_chip chip;
	struct device *dev;
	enum mxs_gpio_id devid;
	u32 both_edges;
};

static inline int is_imx23_gpio(struct mxs_gpio_port *port)
{
	return port->devid == IMX23_GPIO;
}

/* Note: This driver assumes 32 GPIOs are handled in one register */

static int mxs_gpio_set_irq_type(struct irq_data *d, unsigned int type)
{
	u32 val;
	u32 pin_mask = 1 << d->hwirq;
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	struct irq_chip_type *ct = irq_data_get_chip_type(d);
	struct mxs_gpio_port *port = gc->private;
	void __iomem *pin_addr;
	int edge;

	if (!(ct->type & type))
		if (irq_setup_alt_chip(d, type))
			return -EINVAL;

	port->both_edges &= ~pin_mask;
	switch (type) {
	case IRQ_TYPE_EDGE_BOTH:
		val = readl(port->base + PINCTRL_DIN(port)) & pin_mask;
		if (val)
			edge = GPIO_INT_FALL_EDGE;
		else
			edge = GPIO_INT_RISE_EDGE;
		port->both_edges |= pin_mask;
		break;
	case IRQ_TYPE_EDGE_RISING:
		edge = GPIO_INT_RISE_EDGE;
		break;
	case IRQ_TYPE_EDGE_FALLING:
		edge = GPIO_INT_FALL_EDGE;
		break;
	case IRQ_TYPE_LEVEL_LOW:
		edge = GPIO_INT_LOW_LEV;
		break;
	case IRQ_TYPE_LEVEL_HIGH:
		edge = GPIO_INT_HIGH_LEV;
		break;
	default:
		return -EINVAL;
	}

	/* set level or edge */
	pin_addr = port->base + PINCTRL_IRQLEV(port);
	if (edge & GPIO_INT_LEV_MASK) {
		writel(pin_mask, pin_addr + MXS_SET);
		writel(pin_mask, port->base + PINCTRL_IRQEN(port) + MXS_SET);
	} else {
		writel(pin_mask, pin_addr + MXS_CLR);
		writel(pin_mask, port->base + PINCTRL_PIN2IRQ(port) + MXS_SET);
	}

	/* set polarity */
	pin_addr = port->base + PINCTRL_IRQPOL(port);
	if (edge & GPIO_INT_POL_MASK)
		writel(pin_mask, pin_addr + MXS_SET);
	else
		writel(pin_mask, pin_addr + MXS_CLR);

	writel(pin_mask, port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);

	return 0;
}

static void mxs_flip_edge(struct mxs_gpio_port *port, u32 gpio)
{
	u32 bit, val, edge;
	void __iomem *pin_addr;

	bit = 1 << gpio;

	pin_addr = port->base + PINCTRL_IRQPOL(port);
	val = readl(pin_addr);
	edge = val & bit;

Annotation

Implementation Notes