drivers/hwmon/pmbus/bpa-rs600.c

Source file repositories/reference/linux-study-clean/drivers/hwmon/pmbus/bpa-rs600.c

File Facts

System
Linux kernel
Corpus path
drivers/hwmon/pmbus/bpa-rs600.c
Extension
.c
Size
4939 bytes
Lines
209
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 BluTek BPA-RS600 Power Supplies
 *
 * Copyright 2021 Allied Telesis Labs
 */

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

enum chips { bpa_rs600, bpd_rs600 };

static int bpa_rs600_read_byte_data(struct i2c_client *client, int page, int reg)
{
	int ret;

	if (page > 0)
		return -ENXIO;

	switch (reg) {
	case PMBUS_FAN_CONFIG_12:
		/*
		 * Two fans are reported in PMBUS_FAN_CONFIG_12 but there is
		 * only one fan in the module. Mask out the FAN2 bits.
		 */
		ret = pmbus_read_byte_data(client, 0, PMBUS_FAN_CONFIG_12);
		if (ret >= 0)
			ret &= ~(PB_FAN_2_INSTALLED | PB_FAN_2_PULSE_MASK);
		break;
	default:
		ret = -ENODATA;
		break;
	}

	return ret;
}

/*
 * The BPA-RS600 violates the PMBus spec. Specifically it treats the
 * mantissa as unsigned. Deal with this here to allow the PMBus core
 * to work with correctly encoded data.
 */
static int bpa_rs600_read_vin(struct i2c_client *client)
{
	int ret, exponent, mantissa;

	ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_READ_VIN);
	if (ret < 0)
		return ret;

	if (ret & BIT(10)) {
		exponent = ret >> 11;
		mantissa = ret & 0x7ff;

		exponent++;
		mantissa >>= 1;

		ret = (exponent << 11) | mantissa;
	}

	return ret;
}

/*
 * Firmware V5.70 incorrectly reports 1640W for MFR_PIN_MAX.
 * Deal with this by returning a sensible value.
 */
static int bpa_rs600_read_pin_max(struct i2c_client *client)
{
	int ret;

	ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_PIN_MAX);
	if (ret < 0)
		return ret;

	/* Detect invalid 1640W (linear encoding) */
	if (ret == 0x0b34)
		/* Report 700W (linear encoding) */
		return 0x095e;

	return ret;
}

static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int phase, int reg)
{
	int ret;

Annotation

Implementation Notes