1 /* 2 * Copyright (c) 2014-2016, NVIDIA CORPORATION. All rights reserved. 3 * 4 * This software is licensed under the terms of the GNU General Public 5 * License version 2, as published by the Free Software Foundation, and 6 * may be copied, distributed, and modified under those terms. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 */ 14 15 #include <linux/module.h> 16 #include <linux/platform_device.h> 17 #include <soc/tegra/fuse.h> 18 19 #include "soctherm.h" 20 21 #define NOMINAL_CALIB_FT 105 22 #define NOMINAL_CALIB_CP 25 23 24 #define FUSE_TSENSOR_CALIB_CP_TS_BASE_MASK 0x1fff 25 #define FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK (0x1fff << 13) 26 #define FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT 13 27 28 #define FUSE_TSENSOR_COMMON 0x180 29 30 /* 31 * Tegra210: Layout of bits in FUSE_TSENSOR_COMMON: 32 * 3 2 1 0 33 * 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 34 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 35 * | BASE_FT | BASE_CP | SHFT_FT | SHIFT_CP | 36 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 37 * 38 * Tegra12x, etc: 39 * In chips prior to Tegra210, this fuse was incorrectly sized as 26 bits, 40 * and didn't hold SHIFT_CP in [31:26]. Therefore these missing six bits 41 * were obtained via the FUSE_SPARE_REALIGNMENT_REG register [5:0]. 42 * 43 * FUSE_TSENSOR_COMMON: 44 * 3 2 1 0 45 * 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 46 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 47 * |-----------| SHFT_FT | BASE_FT | BASE_CP | 48 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 49 * 50 * FUSE_SPARE_REALIGNMENT_REG: 51 * 3 2 1 0 52 * 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 53 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 54 * |---------------------------------------------------| SHIFT_CP | 55 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 56 */ 57 58 #define CALIB_COEFFICIENT 1000000LL 59 60 /** 61 * div64_s64_precise() - wrapper for div64_s64() 62 * @a: the dividend 63 * @b: the divisor 64 * 65 * Implements division with fairly accurate rounding instead of truncation by 66 * shifting the dividend to the left by 16 so that the quotient has a 67 * much higher precision. 68 * 69 * Return: the quotient of a / b. 70 */ 71 static s64 div64_s64_precise(s64 a, s32 b) 72 { 73 s64 r, al; 74 75 /* Scale up for increased precision division */ 76 al = a << 16; 77 78 r = div64_s64(al * 2 + 1, 2 * b); 79 return r >> 16; 80 } 81 82 int tegra_calc_shared_calib(const struct tegra_soctherm_fuse *tfuse, 83 struct tsensor_shared_calib *shared) 84 { 85 u32 val; 86 s32 shifted_cp, shifted_ft; 87 int err; 88 89 err = tegra_fuse_readl(FUSE_TSENSOR_COMMON, &val); 90 if (err) 91 return err; 92 93 shared->base_cp = (val & tfuse->fuse_base_cp_mask) >> 94 tfuse->fuse_base_cp_shift; 95 shared->base_ft = (val & tfuse->fuse_base_ft_mask) >> 96 tfuse->fuse_base_ft_shift; 97 98 shifted_ft = (val & tfuse->fuse_shift_ft_mask) >> 99 tfuse->fuse_shift_ft_shift; 100 shifted_ft = sign_extend32(shifted_ft, 4); 101 102 if (tfuse->fuse_spare_realignment) { 103 err = tegra_fuse_readl(tfuse->fuse_spare_realignment, &val); 104 if (err) 105 return err; 106 } 107 108 shifted_cp = sign_extend32(val, 5); 109 110 shared->actual_temp_cp = 2 * NOMINAL_CALIB_CP + shifted_cp; 111 shared->actual_temp_ft = 2 * NOMINAL_CALIB_FT + shifted_ft; 112 113 return 0; 114 } 115 116 int tegra_calc_tsensor_calib(const struct tegra_tsensor *sensor, 117 const struct tsensor_shared_calib *shared, 118 u32 *calibration) 119 { 120 const struct tegra_tsensor_group *sensor_group; 121 u32 val, calib; 122 s32 actual_tsensor_ft, actual_tsensor_cp; 123 s32 delta_sens, delta_temp; 124 s32 mult, div; 125 s16 therma, thermb; 126 s64 temp; 127 int err; 128 129 sensor_group = sensor->group; 130 131 err = tegra_fuse_readl(sensor->calib_fuse_offset, &val); 132 if (err) 133 return err; 134 135 actual_tsensor_cp = (shared->base_cp * 64) + sign_extend32(val, 12); 136 val = (val & FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK) >> 137 FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT; 138 actual_tsensor_ft = (shared->base_ft * 32) + sign_extend32(val, 12); 139 140 delta_sens = actual_tsensor_ft - actual_tsensor_cp; 141 delta_temp = shared->actual_temp_ft - shared->actual_temp_cp; 142 143 mult = sensor_group->pdiv * sensor->config->tsample_ate; 144 div = sensor->config->tsample * sensor_group->pdiv_ate; 145 146 temp = (s64)delta_temp * (1LL << 13) * mult; 147 therma = div64_s64_precise(temp, (s64)delta_sens * div); 148 149 temp = ((s64)actual_tsensor_ft * shared->actual_temp_cp) - 150 ((s64)actual_tsensor_cp * shared->actual_temp_ft); 151 thermb = div64_s64_precise(temp, delta_sens); 152 153 temp = (s64)therma * sensor->fuse_corr_alpha; 154 therma = div64_s64_precise(temp, CALIB_COEFFICIENT); 155 156 temp = (s64)thermb * sensor->fuse_corr_alpha + sensor->fuse_corr_beta; 157 thermb = div64_s64_precise(temp, CALIB_COEFFICIENT); 158 159 calib = ((u16)therma << SENSOR_CONFIG2_THERMA_SHIFT) | 160 ((u16)thermb << SENSOR_CONFIG2_THERMB_SHIFT); 161 162 *calibration = calib; 163 164 return 0; 165 } 166 167 MODULE_AUTHOR("Wei Ni <wni@nvidia.com>"); 168 MODULE_DESCRIPTION("Tegra SOCTHERM fuse management"); 169 MODULE_LICENSE("GPL v2"); 170