1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/*
* (C) Copyright 2014 Freescale Semiconductor, Inc.
* Author: Nitin Garg <nitin.garg@freescale.com>
* Ye Li <Ye.Li@freescale.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <common.h>
#include <div64.h>
#include <fuse.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <dm.h>
#include <errno.h>
#include <malloc.h>
#include <thermal.h>
#include <imx_thermal.h>
#define TEMPERATURE_MIN -40
#define TEMPERATURE_HOT 80
#define TEMPERATURE_MAX 125
#define FACTOR0 10000000
#define FACTOR1 15976
#define FACTOR2 4297157
#define MEASURE_FREQ 327
#define TEMPSENSE0_TEMP_CNT_SHIFT 8
#define TEMPSENSE0_TEMP_CNT_MASK (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
#define TEMPSENSE0_FINISHED (1 << 2)
#define TEMPSENSE0_MEASURE_TEMP (1 << 1)
#define TEMPSENSE0_POWER_DOWN (1 << 0)
#define MISC0_REFTOP_SELBIASOFF (1 << 3)
#define TEMPSENSE1_MEASURE_FREQ 0xffff
static int read_cpu_temperature(struct udevice *dev)
{
int temperature;
unsigned int reg, n_meas;
const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
struct anatop_regs *anatop = (struct anatop_regs *)pdata->regs;
unsigned int *priv = dev_get_priv(dev);
u32 fuse = *priv;
int t1, n1;
u32 c1, c2;
u64 temp64;
/*
* Sensor data layout:
* [31:20] - sensor value @ 25C
* We use universal formula now and only need sensor value @ 25C
* slope = 0.4297157 - (0.0015976 * 25C fuse)
*/
n1 = fuse >> 20;
t1 = 25; /* t1 always 25C */
/*
* Derived from linear interpolation:
* slope = 0.4297157 - (0.0015976 * 25C fuse)
* slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
* (Nmeas - n1) / (Tmeas - t1) = slope
* We want to reduce this down to the minimum computation necessary
* for each temperature read. Also, we want Tmeas in millicelsius
* and we don't want to lose precision from integer division. So...
* Tmeas = (Nmeas - n1) / slope + t1
* milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
* milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
* Let constant c1 = (-1000 / slope)
* milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
* Let constant c2 = n1 *c1 + 1000 * t1
* milli_Tmeas = c2 - Nmeas * c1
*/
temp64 = FACTOR0;
temp64 *= 1000;
do_div(temp64, FACTOR1 * n1 - FACTOR2);
c1 = temp64;
c2 = n1 * c1 + 1000 * t1;
/*
* now we only use single measure, every time we read
* the temperature, we will power on/down anadig thermal
* module
*/
writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_clr);
writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_set);
/* setup measure freq */
reg = readl(&anatop->tempsense1);
reg &= ~TEMPSENSE1_MEASURE_FREQ;
reg |= MEASURE_FREQ;
writel(reg, &anatop->tempsense1);
/* start the measurement process */
writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_clr);
writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_set);
/* make sure that the latest temp is valid */
while ((readl(&anatop->tempsense0) &
TEMPSENSE0_FINISHED) == 0)
udelay(10000);
/* read temperature count */
reg = readl(&anatop->tempsense0);
n_meas = (reg & TEMPSENSE0_TEMP_CNT_MASK)
>> TEMPSENSE0_TEMP_CNT_SHIFT;
writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
/* milli_Tmeas = c2 - Nmeas * c1 */
temperature = (c2 - n_meas * c1)/1000;
/* power down anatop thermal sensor */
writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set);
writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_clr);
return temperature;
}
int imx_thermal_get_temp(struct udevice *dev, int *temp)
{
int cpu_tmp = 0;
cpu_tmp = read_cpu_temperature(dev);
while (cpu_tmp > TEMPERATURE_MIN && cpu_tmp < TEMPERATURE_MAX) {
if (cpu_tmp >= TEMPERATURE_HOT) {
printf("CPU Temperature is %d C, too hot to boot, waiting...\n",
cpu_tmp);
udelay(5000000);
cpu_tmp = read_cpu_temperature(dev);
} else {
break;
}
}
*temp = cpu_tmp;
return 0;
}
static const struct dm_thermal_ops imx_thermal_ops = {
.get_temp = imx_thermal_get_temp,
};
static int imx_thermal_probe(struct udevice *dev)
{
unsigned int fuse = ~0;
const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
unsigned int *priv = dev_get_priv(dev);
/* Read Temperature calibration data fuse */
fuse_read(pdata->fuse_bank, pdata->fuse_word, &fuse);
/* Check for valid fuse */
if (fuse == 0 || fuse == ~0) {
printf("CPU: Thermal invalid data, fuse: 0x%x\n", fuse);
return -EPERM;
} else {
printf("CPU: Thermal calibration data: 0x%x\n", fuse);
}
*priv = fuse;
enable_thermal_clk();
return 0;
}
U_BOOT_DRIVER(imx_thermal) = {
.name = "imx_thermal",
.id = UCLASS_THERMAL,
.ops = &imx_thermal_ops,
.probe = imx_thermal_probe,
.priv_auto_alloc_size = sizeof(unsigned int),
.flags = DM_FLAG_PRE_RELOC,
};
|
