drivers/watchdog/imgpdc_wdt.c

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

File Facts

System
Linux kernel
Corpus path
drivers/watchdog/imgpdc_wdt.c
Extension
.c
Size
8430 bytes
Lines
292
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 pdc_wdt_dev {
	struct watchdog_device wdt_dev;
	struct clk *wdt_clk;
	struct clk *sys_clk;
	void __iomem *base;
};

static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev)
{
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	writel(PDC_WDT_TICKLE1_MAGIC, wdt->base + PDC_WDT_TICKLE1);
	writel(PDC_WDT_TICKLE2_MAGIC, wdt->base + PDC_WDT_TICKLE2);

	return 0;
}

static int pdc_wdt_stop(struct watchdog_device *wdt_dev)
{
	unsigned int val;
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	val = readl(wdt->base + PDC_WDT_CONFIG);
	val &= ~PDC_WDT_CONFIG_ENABLE;
	writel(val, wdt->base + PDC_WDT_CONFIG);

	/* Must tickle to finish the stop */
	pdc_wdt_keepalive(wdt_dev);

	return 0;
}

static void __pdc_wdt_set_timeout(struct pdc_wdt_dev *wdt)
{
	unsigned long clk_rate = clk_get_rate(wdt->wdt_clk);
	unsigned int val;

	val = readl(wdt->base + PDC_WDT_CONFIG) & ~PDC_WDT_CONFIG_DELAY_MASK;
	val |= order_base_2(wdt->wdt_dev.timeout * clk_rate) - 1;
	writel(val, wdt->base + PDC_WDT_CONFIG);
}

static int pdc_wdt_set_timeout(struct watchdog_device *wdt_dev,
			       unsigned int new_timeout)
{
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	wdt->wdt_dev.timeout = new_timeout;

	__pdc_wdt_set_timeout(wdt);

	return 0;
}

/* Start the watchdog timer (delay should already be set) */
static int pdc_wdt_start(struct watchdog_device *wdt_dev)
{
	unsigned int val;
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	__pdc_wdt_set_timeout(wdt);

	val = readl(wdt->base + PDC_WDT_CONFIG);
	val |= PDC_WDT_CONFIG_ENABLE;
	writel(val, wdt->base + PDC_WDT_CONFIG);

	return 0;
}

static int pdc_wdt_restart(struct watchdog_device *wdt_dev,
			   unsigned long action, void *data)
{
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	/* Assert SOFT_RESET */
	writel(0x1, wdt->base + PDC_WDT_SOFT_RESET);

	return 0;
}

static const struct watchdog_info pdc_wdt_info = {
	.identity	= "IMG PDC Watchdog",
	.options	= WDIOF_SETTIMEOUT |
			  WDIOF_KEEPALIVEPING |
			  WDIOF_MAGICCLOSE,
};

static const struct watchdog_ops pdc_wdt_ops = {
	.owner		= THIS_MODULE,
	.start		= pdc_wdt_start,

Annotation

Implementation Notes