soctherm-fuse.c (4942B)
1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (c) 2014-2016, NVIDIA CORPORATION. All rights reserved. 4 */ 5 6#include <linux/module.h> 7#include <linux/platform_device.h> 8#include <soc/tegra/fuse.h> 9 10#include "soctherm.h" 11 12#define NOMINAL_CALIB_FT 105 13#define NOMINAL_CALIB_CP 25 14 15#define FUSE_TSENSOR_CALIB_CP_TS_BASE_MASK 0x1fff 16#define FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK (0x1fff << 13) 17#define FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT 13 18 19#define FUSE_TSENSOR_COMMON 0x180 20 21/* 22 * Tegra210: Layout of bits in FUSE_TSENSOR_COMMON: 23 * 3 2 1 0 24 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 25 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 26 * | BASE_FT | BASE_CP | SHFT_FT | SHIFT_CP | 27 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 28 * 29 * Tegra12x, etc: 30 * In chips prior to Tegra210, this fuse was incorrectly sized as 26 bits, 31 * and didn't hold SHIFT_CP in [31:26]. Therefore these missing six bits 32 * were obtained via the FUSE_SPARE_REALIGNMENT_REG register [5:0]. 33 * 34 * FUSE_TSENSOR_COMMON: 35 * 3 2 1 0 36 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 37 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 38 * |-----------| SHFT_FT | BASE_FT | BASE_CP | 39 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 40 * 41 * FUSE_SPARE_REALIGNMENT_REG: 42 * 3 2 1 0 43 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 44 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 45 * |---------------------------------------------------| SHIFT_CP | 46 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 47 */ 48 49#define CALIB_COEFFICIENT 1000000LL 50 51/** 52 * div64_s64_precise() - wrapper for div64_s64() 53 * @a: the dividend 54 * @b: the divisor 55 * 56 * Implements division with fairly accurate rounding instead of truncation by 57 * shifting the dividend to the left by 16 so that the quotient has a 58 * much higher precision. 59 * 60 * Return: the quotient of a / b. 61 */ 62static s64 div64_s64_precise(s64 a, s32 b) 63{ 64 s64 r, al; 65 66 /* Scale up for increased precision division */ 67 al = a << 16; 68 69 r = div64_s64(al * 2 + 1, 2 * b); 70 return r >> 16; 71} 72 73int tegra_calc_shared_calib(const struct tegra_soctherm_fuse *tfuse, 74 struct tsensor_shared_calib *shared) 75{ 76 u32 val; 77 s32 shifted_cp, shifted_ft; 78 int err; 79 80 err = tegra_fuse_readl(FUSE_TSENSOR_COMMON, &val); 81 if (err) 82 return err; 83 84 shared->base_cp = (val & tfuse->fuse_base_cp_mask) >> 85 tfuse->fuse_base_cp_shift; 86 shared->base_ft = (val & tfuse->fuse_base_ft_mask) >> 87 tfuse->fuse_base_ft_shift; 88 89 shifted_ft = (val & tfuse->fuse_shift_ft_mask) >> 90 tfuse->fuse_shift_ft_shift; 91 shifted_ft = sign_extend32(shifted_ft, 4); 92 93 if (tfuse->fuse_spare_realignment) { 94 err = tegra_fuse_readl(tfuse->fuse_spare_realignment, &val); 95 if (err) 96 return err; 97 } 98 99 shifted_cp = sign_extend32(val, 5); 100 101 shared->actual_temp_cp = 2 * NOMINAL_CALIB_CP + shifted_cp; 102 shared->actual_temp_ft = 2 * NOMINAL_CALIB_FT + shifted_ft; 103 104 return 0; 105} 106 107int tegra_calc_tsensor_calib(const struct tegra_tsensor *sensor, 108 const struct tsensor_shared_calib *shared, 109 u32 *calibration) 110{ 111 const struct tegra_tsensor_group *sensor_group; 112 u32 val, calib; 113 s32 actual_tsensor_ft, actual_tsensor_cp; 114 s32 delta_sens, delta_temp; 115 s32 mult, div; 116 s16 therma, thermb; 117 s64 temp; 118 int err; 119 120 sensor_group = sensor->group; 121 122 err = tegra_fuse_readl(sensor->calib_fuse_offset, &val); 123 if (err) 124 return err; 125 126 actual_tsensor_cp = (shared->base_cp * 64) + sign_extend32(val, 12); 127 val = (val & FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK) >> 128 FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT; 129 actual_tsensor_ft = (shared->base_ft * 32) + sign_extend32(val, 12); 130 131 delta_sens = actual_tsensor_ft - actual_tsensor_cp; 132 delta_temp = shared->actual_temp_ft - shared->actual_temp_cp; 133 134 mult = sensor_group->pdiv * sensor->config->tsample_ate; 135 div = sensor->config->tsample * sensor_group->pdiv_ate; 136 137 temp = (s64)delta_temp * (1LL << 13) * mult; 138 therma = div64_s64_precise(temp, (s64)delta_sens * div); 139 140 temp = ((s64)actual_tsensor_ft * shared->actual_temp_cp) - 141 ((s64)actual_tsensor_cp * shared->actual_temp_ft); 142 thermb = div64_s64_precise(temp, delta_sens); 143 144 temp = (s64)therma * sensor->fuse_corr_alpha; 145 therma = div64_s64_precise(temp, CALIB_COEFFICIENT); 146 147 temp = (s64)thermb * sensor->fuse_corr_alpha + sensor->fuse_corr_beta; 148 thermb = div64_s64_precise(temp, CALIB_COEFFICIENT); 149 150 calib = ((u16)therma << SENSOR_CONFIG2_THERMA_SHIFT) | 151 ((u16)thermb << SENSOR_CONFIG2_THERMB_SHIFT); 152 153 *calibration = calib; 154 155 return 0; 156} 157 158MODULE_AUTHOR("Wei Ni <wni@nvidia.com>"); 159MODULE_DESCRIPTION("Tegra SOCTHERM fuse management"); 160MODULE_LICENSE("GPL v2");