linux/drivers/macintosh/windfarm_mpu.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Windfarm PowerMac thermal control
 *
 * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
 */

#ifndef __WINDFARM_MPU_H
#define __WINDFARM_MPU_H

typedef unsigned short fu16;
typedef int fs32;
typedef short fs16;

/* Definition of the MPU data structure which contains per CPU
 * calibration information (among others) for the G5 machines
 */
struct mpu_data
{
	u8	signature;		/* 0x00 - EEPROM sig. */
	u8	bytes_used;		/* 0x01 - Bytes used in eeprom (160 ?) */
	u8	size;			/* 0x02 - EEPROM size (256 ?) */
	u8	version;		/* 0x03 - EEPROM version */
	u32	data_revision;		/* 0x04 - Dataset revision */
	u8	processor_bin_code[3];	/* 0x08 - Processor BIN code */
	u8	bin_code_expansion;	/* 0x0b - ??? (padding ?) */
	u8	processor_num;		/* 0x0c - Number of CPUs on this MPU */
	u8	input_mul_bus_div;	/* 0x0d - Clock input multiplier/bus divider */
	u8	reserved1[2];		/* 0x0e - */
	u32	input_clk_freq_high;	/* 0x10 - Input clock frequency high */
	u8	cpu_nb_target_cycles;	/* 0x14 - ??? */
	u8	cpu_statlat;		/* 0x15 - ??? */
	u8	cpu_snooplat;		/* 0x16 - ??? */
	u8	cpu_snoopacc;		/* 0x17 - ??? */
	u8	nb_paamwin;		/* 0x18 - ??? */
	u8	nb_statlat;		/* 0x19 - ??? */
	u8	nb_snooplat;		/* 0x1a - ??? */
	u8	nb_snoopwin;		/* 0x1b - ??? */
	u8	api_bus_mode;		/* 0x1c - ??? */
	u8	reserved2[3];		/* 0x1d - */
	u32	input_clk_freq_low;	/* 0x20 - Input clock frequency low */
	u8	processor_card_slot;	/* 0x24 - Processor card slot number */
	u8	reserved3[2];		/* 0x25 - */
	u8	padjmax;       		/* 0x27 - Max power adjustment (Not in OF!) */
	u8	ttarget;		/* 0x28 - Target temperature */
	u8	tmax;			/* 0x29 - Max temperature */
	u8	pmaxh;			/* 0x2a - Max power */
	u8	tguardband;		/* 0x2b - Guardband temp ??? Hist. len in OSX */
	fs32	pid_gp;			/* 0x2c - PID proportional gain */
	fs32	pid_gr;			/* 0x30 - PID reset gain */
	fs32	pid_gd;			/* 0x34 - PID derivative gain */
	fu16	voph;			/* 0x38 - Vop High */
	fu16	vopl;			/* 0x3a - Vop Low */
	fs16	nactual_die;		/* 0x3c - nActual Die */
	fs16	nactual_heatsink;	/* 0x3e - nActual Heatsink */
	fs16	nactual_system;		/* 0x40 - nActual System */
	u16	calibration_flags;	/* 0x42 - Calibration flags */
	fu16	mdiode;			/* 0x44 - Diode M value (scaling factor) */
	fs16	bdiode;			/* 0x46 - Diode B value (offset) */
	fs32	theta_heat_sink;	/* 0x48 - Theta heat sink */
	u16	rminn_intake_fan;	/* 0x4c - Intake fan min RPM */
	u16	rmaxn_intake_fan;	/* 0x4e - Intake fan max RPM */
	u16	rminn_exhaust_fan;	/* 0x50 - Exhaust fan min RPM */
	u16	rmaxn_exhaust_fan;	/* 0x52 - Exhaust fan max RPM */
	u8	processor_part_num[8];	/* 0x54 - Processor part number XX pumps min/max */
	u32	processor_lot_num;	/* 0x5c - Processor lot number */
	u8	orig_card_sernum[0x10];	/* 0x60 - Card original serial number */
	u8	curr_card_sernum[0x10];	/* 0x70 - Card current serial number */
	u8	mlb_sernum[0x18];	/* 0x80 - MLB serial number */
	u32	checksum1;		/* 0x98 - */
	u32	checksum2;		/* 0x9c - */	
}; /* Total size = 0xa0 */

static inline const struct mpu_data *wf_get_mpu(int cpu)
{
	struct device_node *np;
	char nodename[64];
	const void *data;
	int len;

	/*
	 * prom.c routine for finding a node by path is a bit brain dead
	 * and requires exact @xxx unit numbers. This is a bit ugly but
	 * will work for these machines
	 */
	sprintf(nodename, "/u3@0,f8000000/i2c@f8001000/cpuid@a%d", cpu ? 2 : 0);
	np = of_find_node_by_path(nodename);
	if (!np)
		return NULL;
	data = of_get_property(np, "cpuid", &len);	
	of_node_put(np);
	if (!data)
		return NULL;

	/*
	 * We are naughty, we have dropped the reference to the device
	 * node and still return a pointer to the content. We know we
	 * can do that though as this is only ever called on PowerMac
	 * which cannot remove those nodes
	 */
	return data;
}

#endif /*  __WINDFARM_MPU_H */