drivers/gpio/gpio-amd-fch.c

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

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-amd-fch.c
Extension
.c
Size
5006 bytes
Lines
195
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 amd_fch_gpio_priv {
	struct gpio_chip		gc;
	void __iomem			*base;
	struct amd_fch_gpio_pdata	*pdata;
	spinlock_t			lock;
};

static void __iomem *amd_fch_gpio_addr(struct amd_fch_gpio_priv *priv,
				       unsigned int gpio)
{
	return priv->base + priv->pdata->gpio_reg[gpio]*sizeof(u32);
}

static int amd_fch_gpio_direction_input(struct gpio_chip *gc,
					unsigned int offset)
{
	unsigned long flags;
	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
	void __iomem *ptr = amd_fch_gpio_addr(priv, offset);

	spin_lock_irqsave(&priv->lock, flags);
	writel_relaxed(readl_relaxed(ptr) & ~AMD_FCH_GPIO_FLAG_DIRECTION, ptr);
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int amd_fch_gpio_direction_output(struct gpio_chip *gc,
					 unsigned int gpio, int value)
{
	unsigned long flags;
	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
	void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
	u32 val;

	spin_lock_irqsave(&priv->lock, flags);

	val = readl_relaxed(ptr);
	if (value)
		val |= AMD_FCH_GPIO_FLAG_WRITE;
	else
		val &= ~AMD_FCH_GPIO_FLAG_WRITE;

	writel_relaxed(val | AMD_FCH_GPIO_FLAG_DIRECTION, ptr);

	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int amd_fch_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio)
{
	int ret;
	unsigned long flags;
	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
	void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);

	spin_lock_irqsave(&priv->lock, flags);
	ret = (readl_relaxed(ptr) & AMD_FCH_GPIO_FLAG_DIRECTION);
	spin_unlock_irqrestore(&priv->lock, flags);

	return ret ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
}

static int amd_fch_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
{
	unsigned long flags;
	struct amd_fch_gpio_priv *priv = gpiochip_get_data(gc);
	void __iomem *ptr = amd_fch_gpio_addr(priv, gpio);
	u32 mask;

	spin_lock_irqsave(&priv->lock, flags);

	mask = readl_relaxed(ptr);
	if (value)
		mask |= AMD_FCH_GPIO_FLAG_WRITE;
	else
		mask &= ~AMD_FCH_GPIO_FLAG_WRITE;
	writel_relaxed(mask, ptr);

	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int amd_fch_gpio_get(struct gpio_chip *gc,
			    unsigned int offset)
{
	unsigned long flags;
	u32 val;

Annotation

Implementation Notes