drivers/acpi/dptf/dptf_pch_fivr.c

Source file repositories/reference/linux-study-clean/drivers/acpi/dptf/dptf_pch_fivr.c

File Facts

System
Linux kernel
Corpus path
drivers/acpi/dptf/dptf_pch_fivr.c
Extension
.c
Size
4351 bytes
Lines
174
Domain
Driver Families
Bucket
drivers/acpi
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 pch_fivr_resp {
	u64 status;
	u64 result;
};

static int pch_fivr_read(acpi_handle handle, char *method, struct pch_fivr_resp *fivr_resp)
{
	struct acpi_buffer resp = { sizeof(struct pch_fivr_resp), fivr_resp};
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	struct acpi_buffer format = { sizeof("NN"), "NN" };
	union acpi_object *obj;
	acpi_status status;
	int ret = -EFAULT;

	status = acpi_evaluate_object(handle, method, NULL, &buffer);
	if (ACPI_FAILURE(status))
		return ret;

	obj = buffer.pointer;
	if (!obj || obj->type != ACPI_TYPE_PACKAGE)
		goto release_buffer;

	status = acpi_extract_package(obj, &format, &resp);
	if (ACPI_FAILURE(status))
		goto release_buffer;

	if (fivr_resp->status)
		goto release_buffer;

	ret = 0;

release_buffer:
	ACPI_FREE(buffer.pointer);
	return ret;
}

/*
 * Presentation of attributes which are defined for INTC10xx
 * They are:
 * freq_mhz_low_clock : Set PCH FIVR switching freq for
 *			FIVR clock 19.2MHz and 24MHz
 * freq_mhz_high_clock : Set PCH FIVR switching freq for
 *			FIVR clock 38.4MHz
 */
#define PCH_FIVR_SHOW(name, method) \
static ssize_t name##_show(struct device *dev,\
			   struct device_attribute *attr,\
			   char *buf)\
{\
	struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
	struct pch_fivr_resp fivr_resp;\
	int status;\
\
	status = pch_fivr_read(acpi_dev->handle, #method, &fivr_resp);\
	if (status)\
		return status;\
\
	return sprintf(buf, "%llu\n", fivr_resp.result);\
}

#define PCH_FIVR_STORE(name, method) \
static ssize_t name##_store(struct device *dev,\
			    struct device_attribute *attr,\
			    const char *buf, size_t count)\
{\
	struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
	acpi_status status;\
	u32 val;\
\
	if (kstrtouint(buf, 0, &val) < 0)\
		return -EINVAL;\
\
	status = acpi_execute_simple_method(acpi_dev->handle, #method, val);\
	if (ACPI_SUCCESS(status))\
		return count;\
\
	return -EINVAL;\
}

PCH_FIVR_SHOW(freq_mhz_low_clock, GFC0)
PCH_FIVR_SHOW(freq_mhz_high_clock, GFC1)
PCH_FIVR_SHOW(ssc_clock_info, GEMI)
PCH_FIVR_SHOW(fivr_switching_freq_mhz, GFCS)
PCH_FIVR_SHOW(fivr_switching_fault_status, GFFS)
PCH_FIVR_STORE(freq_mhz_low_clock, RFC0)
PCH_FIVR_STORE(freq_mhz_high_clock, RFC1)

static DEVICE_ATTR_RW(freq_mhz_low_clock);
static DEVICE_ATTR_RW(freq_mhz_high_clock);
static DEVICE_ATTR_RO(ssc_clock_info);

Annotation

Implementation Notes