arch/arm/mach-tegra/fuse.c

// SPDX-License-Identifier: GPL-2.0+
/*
 *  (C) Copyright 2012-2013
 *  NVIDIA Corporation <www.nvidia.com>
 *
 *  (C) Copyright 2022
 *  Svyatoslav Ryhel <clamor95@gmail.com>
 */

#include <linux/delay.h>
#include <asm/io.h>

#include <asm/arch/tegra.h>
#include <asm/arch/gp_padctrl.h>
#include <asm/arch/clock.h>
#include <asm/arch-tegra/fuse.h>

#include "cpu.h"

#define FUSE_UID_LOW		0x108
#define FUSE_UID_HIGH		0x10c

#define FUSE_VENDOR_CODE	0x200
#define FUSE_FAB_CODE		0x204
#define FUSE_LOT_CODE_0		0x208
#define FUSE_LOT_CODE_1		0x20c
#define FUSE_WAFER_ID		0x210
#define FUSE_X_COORDINATE	0x214
#define FUSE_Y_COORDINATE	0x218

#define FUSE_VENDOR_CODE_MASK	0xf
#define FUSE_FAB_CODE_MASK	0x3f
#define FUSE_WAFER_ID_MASK	0x3f
#define FUSE_X_COORDINATE_MASK	0x1ff
#define FUSE_Y_COORDINATE_MASK	0x1ff

static u32 tegra_fuse_readl(unsigned long offset)
{
	return readl(NV_PA_FUSE_BASE + offset);
}

static void tegra_fuse_init(void)
{
	u32 reg;

	/*
	 * Performed by downstream and is not
	 * documented by TRM. Whithout setting
	 * this bit fuse region will not work.
	 */
	reg = readl_relaxed(NV_PA_CLK_RST_BASE + 0x48);
	reg |= BIT(28);
	writel(reg, NV_PA_CLK_RST_BASE + 0x48);

	clock_enable(PERIPH_ID_FUSE);
	udelay(2);
	reset_set_enable(PERIPH_ID_FUSE, 0);
}

unsigned long long tegra_chip_uid(void)
{
	u64 uid = 0ull;
	u32 reg;
	u32 cid;
	u32 vendor;
	u32 fab;
	u32 lot;
	u32 wafer;
	u32 x;
	u32 y;
	u32 i;

	tegra_fuse_init();

	/* This used to be so much easier in prior chips. Unfortunately, there
	   is no one-stop shopping for the unique id anymore. It must be
	   constructed from various bits of information burned into the fuses
	   during the manufacturing process. The 64-bit unique id is formed
	   by concatenating several bit fields. The notation used for the
	   various fields is <fieldname:size_in_bits> with the UID composed
	   thusly:
	   <CID:4><VENDOR:4><FAB:6><LOT:26><WAFER:6><X:9><Y:9>
	   Where:
		Field    Bits  Position Data
		-------  ----  -------- ----------------------------------------
		CID        4     60     Chip id
		VENDOR     4     56     Vendor code
		FAB        6     50     FAB code
		LOT       26     24     Lot code (5-digit base-36-coded-decimal,
					re-encoded to 26 bits binary)
		WAFER      6     18     Wafer id
		X          9      9     Wafer X-coordinate
		Y          9      0     Wafer Y-coordinate
		-------  ----
		Total     64
	*/

	switch (tegra_get_chip()) {
	case CHIPID_TEGRA20:
		/* T20 has simple calculation */
		return ((unsigned long long)tegra_fuse_readl(FUSE_UID_HIGH) << 32ull) |
			(unsigned long long)tegra_fuse_readl(FUSE_UID_LOW);
	case CHIPID_TEGRA30:
		/* T30 chip id is 0 */
		cid = 0;
		break;
	case CHIPID_TEGRA114:
		/* T11x chip id is 1 */
		cid = 1;
		break;
	case CHIPID_TEGRA124:
		/* T12x chip id is 3 */
		cid = 3;
		break;
	case CHIPID_TEGRA210:
		/* T210 chip id is 5 */
		cid = 5;
	default:
		return 0;
	}

	vendor = tegra_fuse_readl(FUSE_VENDOR_CODE) & FUSE_VENDOR_CODE_MASK;
	fab = tegra_fuse_readl(FUSE_FAB_CODE) & FUSE_FAB_CODE_MASK;

	/* Lot code must be re-encoded from a 5 digit base-36 'BCD' number
	   to a binary number. */
	lot = 0;
	reg = tegra_fuse_readl(FUSE_LOT_CODE_0) << 2;

	for (i = 0; i < 5; ++i) {
		u32 digit = (reg & 0xFC000000) >> 26;
		lot *= 36;
		lot += digit;
		reg <<= 6;
	}

	wafer = tegra_fuse_readl(FUSE_WAFER_ID) & FUSE_WAFER_ID_MASK;
	x = tegra_fuse_readl(FUSE_X_COORDINATE) & FUSE_X_COORDINATE_MASK;
	y = tegra_fuse_readl(FUSE_Y_COORDINATE) & FUSE_Y_COORDINATE_MASK;

	uid = ((unsigned long long)cid  << 60ull)
	    | ((unsigned long long)vendor << 56ull)
	    | ((unsigned long long)fab << 50ull)
	    | ((unsigned long long)lot << 24ull)
	    | ((unsigned long long)wafer << 18ull)
	    | ((unsigned long long)x << 9ull)
	    | ((unsigned long long)y << 0ull);

	return uid;
}