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 */
div64_s64_precise(s64 a,s32 b)62 static 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
tegra_calc_shared_calib(const struct tegra_soctherm_fuse * tfuse,struct tsensor_shared_calib * shared)73 int 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
tegra_calc_tsensor_calib(const struct tegra_tsensor * sensor,const struct tsensor_shared_calib * shared,u32 * calibration)107 int 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
158 MODULE_AUTHOR("Wei Ni <wni@nvidia.com>");
159 MODULE_DESCRIPTION("Tegra SOCTHERM fuse management");
160 MODULE_LICENSE("GPL v2");
161