drivers/hwmon/pmbus/mp2993.c

Source file repositories/reference/linux-study-clean/drivers/hwmon/pmbus/mp2993.c

File Facts

System
Linux kernel
Corpus path
drivers/hwmon/pmbus/mp2993.c
Extension
.c
Size
7146 bytes
Lines
262
Domain
Driver Families
Bucket
drivers/hwmon
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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers(MP2993)
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include "pmbus.h"

#define MP2993_VOUT_OVUV_UINT	125
#define MP2993_VOUT_OVUV_DIV	64
#define MP2993_VIN_LIMIT_UINT	1
#define MP2993_VIN_LIMIT_DIV	8
#define MP2993_READ_VIN_UINT	1
#define MP2993_READ_VIN_DIV	32

#define MP2993_PAGE_NUM	2

#define MP2993_RAIL1_FUNC	(PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | \
							PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT | \
							PMBUS_HAVE_TEMP | PMBUS_HAVE_PIN | \
							PMBUS_HAVE_IIN | \
							PMBUS_HAVE_STATUS_VOUT | \
							PMBUS_HAVE_STATUS_IOUT | \
							PMBUS_HAVE_STATUS_TEMP | \
							PMBUS_HAVE_STATUS_INPUT)

#define MP2993_RAIL2_FUNC	(PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | \
							 PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP | \
							 PMBUS_HAVE_STATUS_VOUT | \
							 PMBUS_HAVE_STATUS_IOUT | \
							 PMBUS_HAVE_STATUS_TEMP | \
							 PMBUS_HAVE_STATUS_INPUT)

/* Converts a linear11 data exponent to a specified value */
static u16 mp2993_linear11_exponent_transfer(u16 word, u16 expect_exponent)
{
	s16 exponent, mantissa, target_exponent;

	exponent = ((s16)word) >> 11;
	mantissa = ((s16)((word & 0x7ff) << 5)) >> 5;
	target_exponent = (s16)((expect_exponent & 0x1f) << 11) >> 11;

	if (exponent > target_exponent)
		mantissa = mantissa << (exponent - target_exponent);
	else
		mantissa = mantissa >> (target_exponent - exponent);

	return (mantissa & 0x7ff) | ((expect_exponent << 11) & 0xf800);
}

static int
mp2993_set_vout_format(struct i2c_client *client, int page, int format)
{
	int ret;

	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
	if (ret < 0)
		return ret;

	return i2c_smbus_write_byte_data(client, PMBUS_VOUT_MODE, format);
}

static int mp2993_identify(struct i2c_client *client, struct pmbus_driver_info *info)
{
	int ret;

	/* Set vout to direct format for rail1. */
	ret = mp2993_set_vout_format(client, 0, PB_VOUT_MODE_DIRECT);
	if (ret < 0)
		return ret;

	/* Set vout to direct format for rail2. */
	return mp2993_set_vout_format(client, 1, PB_VOUT_MODE_DIRECT);
}

static int mp2993_read_word_data(struct i2c_client *client, int page, int phase,
				 int reg)
{
	int ret;

	switch (reg) {
	case PMBUS_VOUT_OV_FAULT_LIMIT:
	case PMBUS_VOUT_UV_FAULT_LIMIT:
		ret = pmbus_read_word_data(client, page, phase, reg);
		if (ret < 0)
			return ret;

		ret = DIV_ROUND_CLOSEST(ret * MP2993_VOUT_OVUV_UINT, MP2993_VOUT_OVUV_DIV);

Annotation

Implementation Notes