drivers/thermal/max77620_thermal.c

Source file repositories/reference/linux-study-clean/drivers/thermal/max77620_thermal.c

File Facts

System
Linux kernel
Corpus path
drivers/thermal/max77620_thermal.c
Extension
.c
Size
4509 bytes
Lines
161
Domain
Driver Families
Bucket
drivers/thermal
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 max77620_therm_info {
	struct device			*dev;
	struct regmap			*rmap;
	struct thermal_zone_device	*tz_device;
	int				irq_tjalarm1;
	int				irq_tjalarm2;
};

/**
 * max77620_thermal_read_temp: Read PMIC die temperatue.
 * @data:	Device specific data.
 * @temp:	Temperature in millidegrees Celsius
 *
 * The actual temperature of PMIC die is not available from PMIC.
 * PMIC only tells the status if it has crossed or not the threshold level
 * of 120degC or 140degC.
 * If threshold has not been crossed then assume die temperature as 100degC
 * else 120degC or 140deG based on the PMIC die temp threshold status.
 *
 * Return 0 on success otherwise error number to show reason of failure.
 */

static int max77620_thermal_read_temp(struct thermal_zone_device *tz, int *temp)
{
	struct max77620_therm_info *mtherm = thermal_zone_device_priv(tz);
	unsigned int val;
	int ret;

	ret = regmap_read(mtherm->rmap, MAX77620_REG_STATLBT, &val);
	if (ret < 0)
		return ret;

	if (val & MAX77620_IRQ_TJALRM2_MASK)
		*temp = MAX77620_TJALARM2_TEMP;
	else if (val & MAX77620_IRQ_TJALRM1_MASK)
		*temp = MAX77620_TJALARM1_TEMP;
	else
		*temp = MAX77620_NORMAL_OPERATING_TEMP;

	return 0;
}

static const struct thermal_zone_device_ops max77620_thermal_ops = {
	.get_temp = max77620_thermal_read_temp,
};

static irqreturn_t max77620_thermal_irq(int irq, void *data)
{
	struct max77620_therm_info *mtherm = data;

	if (irq == mtherm->irq_tjalarm1)
		dev_warn(mtherm->dev, "Junction Temp Alarm1(120C) occurred\n");
	else if (irq == mtherm->irq_tjalarm2)
		dev_crit(mtherm->dev, "Junction Temp Alarm2(140C) occurred\n");

	thermal_zone_device_update(mtherm->tz_device,
				   THERMAL_EVENT_UNSPECIFIED);

	return IRQ_HANDLED;
}

static int max77620_thermal_probe(struct platform_device *pdev)
{
	struct max77620_therm_info *mtherm;
	int ret;

	mtherm = devm_kzalloc(&pdev->dev, sizeof(*mtherm), GFP_KERNEL);
	if (!mtherm)
		return -ENOMEM;

	mtherm->irq_tjalarm1 = platform_get_irq(pdev, 0);
	mtherm->irq_tjalarm2 = platform_get_irq(pdev, 1);
	if ((mtherm->irq_tjalarm1 < 0) || (mtherm->irq_tjalarm2 < 0)) {
		dev_err(&pdev->dev, "Alarm irq number not available\n");
		return -EINVAL;
	}

	mtherm->dev = &pdev->dev;
	mtherm->rmap = dev_get_regmap(pdev->dev.parent, NULL);
	if (!mtherm->rmap) {
		dev_err(&pdev->dev, "Failed to get parent regmap\n");
		return -ENODEV;
	}

	/*
	 * The reference taken to the parent's node which will be balanced on
	 * reprobe or on platform-device release.
	 */
	device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);

Annotation

Implementation Notes