drivers/thermal/imx_sc_thermal.c

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

File Facts

System
Linux kernel
Corpus path
drivers/thermal/imx_sc_thermal.c
Extension
.c
Size
3421 bytes
Lines
147
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 imx_sc_sensor {
	struct thermal_zone_device *tzd;
	u32 resource_id;
};

struct req_get_temp {
	u16 resource_id;
	u8 type;
} __packed __aligned(4);

struct resp_get_temp {
	s16 celsius;
	s8 tenths;
} __packed __aligned(4);

struct imx_sc_msg_misc_get_temp {
	struct imx_sc_rpc_msg hdr;
	union {
		struct req_get_temp req;
		struct resp_get_temp resp;
	} data;
} __packed __aligned(4);

static int imx_sc_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
{
	struct imx_sc_msg_misc_get_temp msg;
	struct imx_sc_rpc_msg *hdr = &msg.hdr;
	struct imx_sc_sensor *sensor = thermal_zone_device_priv(tz);
	int ret;

	msg.data.req.resource_id = sensor->resource_id;
	msg.data.req.type = IMX_SC_C_TEMP;

	hdr->ver = IMX_SC_RPC_VERSION;
	hdr->svc = IMX_SC_RPC_SVC_MISC;
	hdr->func = IMX_SC_MISC_FUNC_GET_TEMP;
	hdr->size = 2;

	ret = imx_scu_call_rpc(thermal_ipc_handle, &msg, true);
	if (ret)
		return ret;

	*temp = msg.data.resp.celsius * 1000 + msg.data.resp.tenths * 100;

	return 0;
}

static const struct thermal_zone_device_ops imx_sc_thermal_ops = {
	.get_temp = imx_sc_thermal_get_temp,
};

static int imx_sc_thermal_probe(struct platform_device *pdev)
{
	struct imx_sc_sensor *sensor;
	const int *resource_id;
	int i, ret;

	ret = imx_scu_get_handle(&thermal_ipc_handle);
	if (ret)
		return ret;

	resource_id = of_device_get_match_data(&pdev->dev);
	if (!resource_id)
		return -EINVAL;

	for (i = 0; resource_id[i] >= 0; i++) {

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

		sensor->resource_id = resource_id[i];

		sensor->tzd = devm_thermal_of_zone_register(&pdev->dev, sensor->resource_id,
							    sensor, &imx_sc_thermal_ops);
		if (IS_ERR(sensor->tzd)) {
			/*
			 * Save the error value before freeing the
			 * sensor pointer, otherwise we endup with a
			 * use-after-free error
			 */
			ret = PTR_ERR(sensor->tzd);

			devm_kfree(&pdev->dev, sensor);

			/*
			 * The thermal framework notifies us there is
			 * no thermal zone description for such a
			 * sensor id
			 */

Annotation

Implementation Notes