drivers/misc/amd-sbi/rmi-i2c.c

Source file repositories/reference/linux-study-clean/drivers/misc/amd-sbi/rmi-i2c.c

File Facts

System
Linux kernel
Corpus path
drivers/misc/amd-sbi/rmi-i2c.c
Extension
.c
Size
6329 bytes
Lines
248
Domain
Driver Families
Bucket
drivers/misc
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
/*
 * rmi-i2c.c - Side band RMI over I2C support for AMD out
 *             of band management
 *
 * Copyright (C) 2024 Advanced Micro Devices, Inc.
 */

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/i3c/device.h>
#include <linux/i3c/master.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include "rmi-core.h"

#define REV_TWO_BYTE_ADDR	0x21

static int sbrmi_enable_alert(struct sbrmi_data *data)
{
	int ctrl, ret;

	/*
	 * Enable the SB-RMI Software alert status
	 * by writing 0 to bit 4 of Control register(0x1)
	 */
	ret = regmap_read(data->regmap, SBRMI_CTRL, &ctrl);
	if (ret < 0)
		return ret;

	if (ctrl & 0x10) {
		ctrl &= ~0x10;
		return regmap_write(data->regmap, SBRMI_CTRL, ctrl);
	}

	return 0;
}

static int sbrmi_get_max_pwr_limit(struct sbrmi_data *data)
{
	struct apml_mbox_msg msg = { 0 };
	int ret;

	msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT;
	ret = rmi_mailbox_xfer(data, &msg);
	if (ret < 0)
		return ret;
	data->pwr_limit_max = msg.mb_in_out;

	return ret;
}

static int sbrmi_common_probe(struct device *dev, struct regmap *regmap, uint8_t address)
{
	struct sbrmi_data *data;
	int ret;

	data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->regmap = regmap;
	mutex_init(&data->lock);

	/* Enable alert for SB-RMI sequence */
	ret = sbrmi_enable_alert(data);
	if (ret < 0)
		return ret;

	/* Cache maximum power limit */
	ret = sbrmi_get_max_pwr_limit(data);
	if (ret < 0)
		return ret;

	data->dev_static_addr = address;

	dev_set_drvdata(dev, data);

	ret = create_hwmon_sensor_device(dev, data);
	if (ret < 0)
		return ret;
	return create_misc_rmi_device(data, dev);
}

static struct regmap_config sbrmi_regmap_config = {
	.reg_bits = 8,

Annotation

Implementation Notes