1 /*
2 * Copyright (c) 2015, The Linux Foundation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 and
6 * only version 2 as published by the Free Software Foundation.
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/err.h>
16 #include <linux/io.h>
17 #include <linux/nvmem-consumer.h>
18 #include <linux/of_address.h>
19 #include <linux/platform_device.h>
20 #include <linux/regmap.h>
21 #include "tsens.h"
22
23 #define S0_ST_ADDR 0x1030
24 #define SN_ADDR_OFFSET 0x4
25 #define SN_ST_TEMP_MASK 0x3ff
26 #define CAL_DEGC_PT1 30
27 #define CAL_DEGC_PT2 120
28 #define SLOPE_FACTOR 1000
29 #define SLOPE_DEFAULT 3200
30
qfprom_read(struct device * dev,const char * cname)31 char *qfprom_read(struct device *dev, const char *cname)
32 {
33 struct nvmem_cell *cell;
34 ssize_t data;
35 char *ret;
36
37 cell = nvmem_cell_get(dev, cname);
38 if (IS_ERR(cell))
39 return ERR_CAST(cell);
40
41 ret = nvmem_cell_read(cell, &data);
42 nvmem_cell_put(cell);
43
44 return ret;
45 }
46
47 /*
48 * Use this function on devices where slope and offset calculations
49 * depend on calibration data read from qfprom. On others the slope
50 * and offset values are derived from tz->tzp->slope and tz->tzp->offset
51 * resp.
52 */
compute_intercept_slope(struct tsens_device * tmdev,u32 * p1,u32 * p2,u32 mode)53 void compute_intercept_slope(struct tsens_device *tmdev, u32 *p1,
54 u32 *p2, u32 mode)
55 {
56 int i;
57 int num, den;
58
59 for (i = 0; i < tmdev->num_sensors; i++) {
60 dev_dbg(tmdev->dev,
61 "sensor%d - data_point1:%#x data_point2:%#x\n",
62 i, p1[i], p2[i]);
63
64 tmdev->sensor[i].slope = SLOPE_DEFAULT;
65 if (mode == TWO_PT_CALIB) {
66 /*
67 * slope (m) = adc_code2 - adc_code1 (y2 - y1)/
68 * temp_120_degc - temp_30_degc (x2 - x1)
69 */
70 num = p2[i] - p1[i];
71 num *= SLOPE_FACTOR;
72 den = CAL_DEGC_PT2 - CAL_DEGC_PT1;
73 tmdev->sensor[i].slope = num / den;
74 }
75
76 tmdev->sensor[i].offset = (p1[i] * SLOPE_FACTOR) -
77 (CAL_DEGC_PT1 *
78 tmdev->sensor[i].slope);
79 dev_dbg(tmdev->dev, "offset:%d\n", tmdev->sensor[i].offset);
80 }
81 }
82
code_to_degc(u32 adc_code,const struct tsens_sensor * s)83 static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s)
84 {
85 int degc, num, den;
86
87 num = (adc_code * SLOPE_FACTOR) - s->offset;
88 den = s->slope;
89
90 if (num > 0)
91 degc = num + (den / 2);
92 else if (num < 0)
93 degc = num - (den / 2);
94 else
95 degc = num;
96
97 degc /= den;
98
99 return degc;
100 }
101
get_temp_common(struct tsens_device * tmdev,int id,int * temp)102 int get_temp_common(struct tsens_device *tmdev, int id, int *temp)
103 {
104 struct tsens_sensor *s = &tmdev->sensor[id];
105 u32 code;
106 unsigned int sensor_addr;
107 int last_temp = 0, ret;
108
109 sensor_addr = S0_ST_ADDR + s->hw_id * SN_ADDR_OFFSET;
110 ret = regmap_read(tmdev->map, sensor_addr, &code);
111 if (ret)
112 return ret;
113 last_temp = code & SN_ST_TEMP_MASK;
114
115 *temp = code_to_degc(last_temp, s) * 1000;
116
117 return 0;
118 }
119
120 static const struct regmap_config tsens_config = {
121 .reg_bits = 32,
122 .val_bits = 32,
123 .reg_stride = 4,
124 };
125
init_common(struct tsens_device * tmdev)126 int __init init_common(struct tsens_device *tmdev)
127 {
128 void __iomem *base;
129
130 base = of_iomap(tmdev->dev->of_node, 0);
131 if (!base)
132 return -EINVAL;
133
134 tmdev->map = devm_regmap_init_mmio(tmdev->dev, base, &tsens_config);
135 if (IS_ERR(tmdev->map)) {
136 iounmap(base);
137 return PTR_ERR(tmdev->map);
138 }
139
140 return 0;
141 }
142