path: root/drivers/hwmon/ibmaem.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * A hwmon driver for the IBM System Director Active Energy Manager (AEM)
 * temperature/power/energy sensors and capping functionality.
 * Copyright (C) 2008 IBM
 *
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/ipmi.h>
#include <linux/module.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include <linux/kdev_t.h>
#include <linux/spinlock.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/platform_device.h>
#include <linux/math64.h>
#include <linux/time.h>
#include <linux/err.h>

#define REFRESH_INTERVAL	(HZ)
#define IPMI_TIMEOUT		(30 * HZ)
#define DRVNAME			"aem"

#define AEM_NETFN		0x2E

#define AEM_FIND_FW_CMD		0x80
#define AEM_ELEMENT_CMD		0x81
#define AEM_FW_INSTANCE_CMD	0x82

#define AEM_READ_ELEMENT_CFG	0x80
#define AEM_READ_BUFFER		0x81
#define AEM_READ_REGISTER	0x82
#define AEM_WRITE_REGISTER	0x83
#define AEM_SET_REG_MASK	0x84
#define AEM_CLEAR_REG_MASK	0x85
#define AEM_READ_ELEMENT_CFG2	0x86

#define AEM_CONTROL_ELEMENT	0
#define AEM_ENERGY_ELEMENT	1
#define AEM_CLOCK_ELEMENT	4
#define AEM_POWER_CAP_ELEMENT	7
#define AEM_EXHAUST_ELEMENT	9
#define AEM_POWER_ELEMENT	10

#define AEM_MODULE_TYPE_ID	0x0001

#define AEM2_NUM_ENERGY_REGS	2
#define AEM2_NUM_PCAP_REGS	6
#define AEM2_NUM_TEMP_REGS	2
#define AEM2_NUM_SENSORS	14

#define AEM1_NUM_ENERGY_REGS	1
#define AEM1_NUM_SENSORS	3

/* AEM 2.x has more energy registers */
#define AEM_NUM_ENERGY_REGS	AEM2_NUM_ENERGY_REGS
/* AEM 2.x needs more sensor files */
#define AEM_NUM_SENSORS		AEM2_NUM_SENSORS

#define POWER_CAP		0
#define POWER_CAP_MAX_HOTPLUG	1
#define POWER_CAP_MAX		2
#define	POWER_CAP_MIN_WARNING	3
#define POWER_CAP_MIN		4
#define	POWER_AUX		5

#define AEM_DEFAULT_POWER_INTERVAL 1000
#define AEM_MIN_POWER_INTERVAL	200
#define UJ_PER_MJ		1000L

static DEFINE_IDA(aem_ida);

static struct platform_driver aem_driver = {
	.driver = {
		.name = DRVNAME,
		.bus = &platform_bus_type,
	}
};

struct aem_ipmi_data {
	struct completion	read_complete;
	struct ipmi_addr	address;
	struct ipmi_user	*user;
	int			interface;

	struct kernel_ipmi_msg	tx_message;
	long			tx_msgid;

	void			*rx_msg_data;
	unsigned short		rx_msg_len;
	unsigned char		rx_result;
	int			rx_recv_type;

	struct device		*bmc_device;
};

struct aem_ro_sensor_template {
	char *label;
	ssize_t (*show)(struct device *dev,
			struct device_attribute *devattr,
			char *buf);
	int index;
};

struct aem_rw_sensor_template {
	char *label;
	ssize_t (*show)(struct device *dev,
			struct device_attribute *devattr,
			char *buf);
	ssize_t (*set)(struct device *dev,
		       struct device_attribute *devattr,
		       const char *buf, size_t count);
	int index;
};

struct aem_data {
	struct list_head	list;

	struct device		*hwmon_dev;
	struct platform_device	*pdev;
	struct mutex		lock;
	bool			valid;
	unsigned long		last_updated;	/* In jiffies */
	u8			ver_major;
	u8			ver_minor;
	u8			module_handle;
	int			id;
	struct aem_ipmi_data	ipmi;

	/* Function and buffer to update sensors */
	void (*update)(struct aem_data *data);
	struct aem_read_sensor_resp *rs_resp;

	/*
	 * AEM 1.x sensors:
	 * Available sensors:
	 * Energy meter
	 * Power meter
	 *
	 * AEM 2.x sensors:
	 * Two energy meters
	 * Two power meters
	 * Two temperature sensors
	 * Six power cap registers
	 */

	/* sysfs attrs */
	struct sensor_device_attribute	sensors[AEM_NUM_SENSORS];

	/* energy use in mJ */
	u64			energy[AEM_NUM_ENERGY_REGS];

	/* power sampling interval in ms */
	unsigned long		power_period[AEM_NUM_ENERGY_REGS];

	/* Everything past here is for AEM2 only */

	/* power caps in dW */
	u16			pcap[AEM2_NUM_PCAP_REGS];

	/* exhaust temperature in C */
	u8			temp[AEM2_NUM_TEMP_REGS];
};

/* Data structures returned by the AEM firmware */
struct aem_iana_id {
	u8			bytes[3];
};
static struct aem_iana_id system_x_id = {
	.bytes = {0x4D, 0x4F, 0x00}
};

/* These are used to find AEM1 instances */
struct aem_find_firmware_req {
	struct aem_iana_id	id;
	u8			rsvd;
	__be16			index;
	__be16			module_type_id;
} __packed;

struct aem_find_firmware_resp {
	struct aem_iana_id	id;
	u8			num_instances;
} __packed;

/* These are used to find AEM2 instances */
struct aem_find_instance_req {
	struct aem_iana_id	id;
	u8			instance_number;
	__be16			module_type_id;
} __packed;

struct aem_find_instance_resp {
	struct aem_iana_id	id;
	u8			num_instances;
	u8			major;
	u8			minor;
	u8			module_handle;
	u16			record_id;
} __packed;

/* These are used to query sensors */
struct aem_read_sensor_req {
	struct aem_iana_id	id;
	u8			module_handle;
	u8			element;
	u8			subcommand;
	u8			reg;
	u8			rx_buf_size;
} __packed;

struct aem_read_sensor_resp {
	struct aem_iana_id	id;
	u8			bytes[];
} __packed;

/* Data structures to talk to the IPMI layer */
struct aem_driver_data {
	struct list_head	aem_devices;
	struct ipmi_smi_watcher	bmc_events;
	struct ipmi_user_hndl	ipmi_hndlrs;
};

static void aem_register_bmc(int iface, struct device *dev);
static void aem_bmc_gone(int iface);
static void aem_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);

static void aem_remove_sensors(struct aem_data *data);
static int aem1_find_sensors(struct aem_data *data);
static