drivers/watchdog/lantiq_wdt.c

Source file repositories/reference/linux-study-clean/drivers/watchdog/lantiq_wdt.c

File Facts

System
Linux kernel
Corpus path
drivers/watchdog/lantiq_wdt.c
Extension
.c
Size
7586 bytes
Lines
290
Domain
Driver Families
Bucket
drivers/watchdog
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 ltq_wdt_hw {
	int (*bootstatus_get)(struct device *dev);
};

struct ltq_wdt_priv {
	struct watchdog_device wdt;
	void __iomem *membase;
	unsigned long clk_rate;
};

static u32 ltq_wdt_r32(struct ltq_wdt_priv *priv, u32 offset)
{
	return __raw_readl(priv->membase + offset);
}

static void ltq_wdt_w32(struct ltq_wdt_priv *priv, u32 val, u32 offset)
{
	__raw_writel(val, priv->membase + offset);
}

static void ltq_wdt_mask(struct ltq_wdt_priv *priv, u32 clear, u32 set,
			 u32 offset)
{
	u32 val = ltq_wdt_r32(priv, offset);

	val &= ~(clear);
	val |= set;
	ltq_wdt_w32(priv, val, offset);
}

static struct ltq_wdt_priv *ltq_wdt_get_priv(struct watchdog_device *wdt)
{
	return container_of(wdt, struct ltq_wdt_priv, wdt);
}

static struct watchdog_info ltq_wdt_info = {
	.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
		   WDIOF_CARDRESET,
	.identity = "ltq_wdt",
};

static int ltq_wdt_start(struct watchdog_device *wdt)
{
	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
	u32 timeout;

	timeout = wdt->timeout * priv->clk_rate;

	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
	/* write the second magic plus the configuration and new timeout */
	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK | LTQ_WDT_CR_MAX_TIMEOUT,
		     LTQ_WDT_CR_GEN | LTQ_WDT_CR_PWL | LTQ_WDT_CR_CLKDIV |
		     LTQ_WDT_CR_PW2 | timeout,
		     LTQ_WDT_CR);

	return 0;
}

static int ltq_wdt_stop(struct watchdog_device *wdt)
{
	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);

	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
	ltq_wdt_mask(priv, LTQ_WDT_CR_GEN | LTQ_WDT_CR_PW_MASK,
		     LTQ_WDT_CR_PW2, LTQ_WDT_CR);

	return 0;
}

static int ltq_wdt_ping(struct watchdog_device *wdt)
{
	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
	u32 timeout;

	timeout = wdt->timeout * priv->clk_rate;

	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK, LTQ_WDT_CR_PW1, LTQ_WDT_CR);
	/* write the second magic plus the configuration and new timeout */
	ltq_wdt_mask(priv, LTQ_WDT_CR_PW_MASK | LTQ_WDT_CR_MAX_TIMEOUT,
		     LTQ_WDT_CR_PW2 | timeout, LTQ_WDT_CR);

	return 0;
}

static unsigned int ltq_wdt_get_timeleft(struct watchdog_device *wdt)
{
	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);
	u64 timeout;

	timeout = ltq_wdt_r32(priv, LTQ_WDT_SR) & LTQ_WDT_SR_VALUE_MASK;

Annotation

Implementation Notes