1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Dove thermal sensor driver
4 *
5 * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch>
6 */
7 #include <linux/device.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/kernel.h>
11 #include <linux/of.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/thermal.h>
15
16 #define DOVE_THERMAL_TEMP_OFFSET 1
17 #define DOVE_THERMAL_TEMP_MASK 0x1FF
18
19 /* Dove Thermal Manager Control and Status Register */
20 #define PMU_TM_DISABLE_OFFS 0
21 #define PMU_TM_DISABLE_MASK (0x1 << PMU_TM_DISABLE_OFFS)
22
23 /* Dove Theraml Diode Control 0 Register */
24 #define PMU_TDC0_SW_RST_MASK (0x1 << 1)
25 #define PMU_TDC0_SEL_VCAL_OFFS 5
26 #define PMU_TDC0_SEL_VCAL_MASK (0x3 << PMU_TDC0_SEL_VCAL_OFFS)
27 #define PMU_TDC0_REF_CAL_CNT_OFFS 11
28 #define PMU_TDC0_REF_CAL_CNT_MASK (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS)
29 #define PMU_TDC0_AVG_NUM_OFFS 25
30 #define PMU_TDC0_AVG_NUM_MASK (0x7 << PMU_TDC0_AVG_NUM_OFFS)
31
32 /* Dove Thermal Diode Control 1 Register */
33 #define PMU_TEMP_DIOD_CTRL1_REG 0x04
34 #define PMU_TDC1_TEMP_VALID_MASK (0x1 << 10)
35
36 /* Dove Thermal Sensor Dev Structure */
37 struct dove_thermal_priv {
38 void __iomem *sensor;
39 void __iomem *control;
40 };
41
dove_init_sensor(const struct dove_thermal_priv * priv)42 static int dove_init_sensor(const struct dove_thermal_priv *priv)
43 {
44 u32 reg;
45 u32 i;
46
47 /* Configure the Diode Control Register #0 */
48 reg = readl_relaxed(priv->control);
49
50 /* Use average of 2 */
51 reg &= ~PMU_TDC0_AVG_NUM_MASK;
52 reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS);
53
54 /* Reference calibration value */
55 reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
56 reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS);
57
58 /* Set the high level reference for calibration */
59 reg &= ~PMU_TDC0_SEL_VCAL_MASK;
60 reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS);
61 writel(reg, priv->control);
62
63 /* Reset the sensor */
64 reg = readl_relaxed(priv->control);
65 writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
66 writel(reg, priv->control);
67
68 /* Enable the sensor */
69 reg = readl_relaxed(priv->sensor);
70 reg &= ~PMU_TM_DISABLE_MASK;
71 writel(reg, priv->sensor);
72
73 /* Poll the sensor for the first reading */
74 for (i = 0; i < 1000000; i++) {
75 reg = readl_relaxed(priv->sensor);
76 if (reg & DOVE_THERMAL_TEMP_MASK)
77 break;
78 }
79
80 if (i == 1000000)
81 return -EIO;
82
83 return 0;
84 }
85
dove_get_temp(struct thermal_zone_device * thermal,int * temp)86 static int dove_get_temp(struct thermal_zone_device *thermal,
87 int *temp)
88 {
89 unsigned long reg;
90 struct dove_thermal_priv *priv = thermal_zone_device_priv(thermal);
91
92 /* Valid check */
93 reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG);
94 if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0)
95 return -EIO;
96
97 /*
98 * Calculate temperature. According to Marvell internal
99 * documentation the formula for this is:
100 * Celsius = (322-reg)/1.3625
101 */
102 reg = readl_relaxed(priv->sensor);
103 reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
104 *temp = ((3220000000UL - (10000000UL * reg)) / 13625);
105
106 return 0;
107 }
108
109 static struct thermal_zone_device_ops ops = {
110 .get_temp = dove_get_temp,
111 };
112
113 static const struct of_device_id dove_thermal_id_table[] = {
114 { .compatible = "marvell,dove-thermal" },
115 {}
116 };
117
dove_thermal_probe(struct platform_device * pdev)118 static int dove_thermal_probe(struct platform_device *pdev)
119 {
120 struct thermal_zone_device *thermal = NULL;
121 struct dove_thermal_priv *priv;
122 int ret;
123
124 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
125 if (!priv)
126 return -ENOMEM;
127
128 priv->sensor = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
129 if (IS_ERR(priv->sensor))
130 return PTR_ERR(priv->sensor);
131
132 priv->control = devm_platform_get_and_ioremap_resource(pdev, 1, NULL);
133 if (IS_ERR(priv->control))
134 return PTR_ERR(priv->control);
135
136 ret = dove_init_sensor(priv);
137 if (ret) {
138 dev_err(&pdev->dev, "Failed to initialize sensor\n");
139 return ret;
140 }
141
142 thermal = thermal_tripless_zone_device_register("dove_thermal", priv,
143 &ops, NULL);
144 if (IS_ERR(thermal)) {
145 dev_err(&pdev->dev,
146 "Failed to register thermal zone device\n");
147 return PTR_ERR(thermal);
148 }
149
150 ret = thermal_zone_device_enable(thermal);
151 if (ret) {
152 thermal_zone_device_unregister(thermal);
153 return ret;
154 }
155
156 platform_set_drvdata(pdev, thermal);
157
158 return 0;
159 }
160
dove_thermal_exit(struct platform_device * pdev)161 static int dove_thermal_exit(struct platform_device *pdev)
162 {
163 struct thermal_zone_device *dove_thermal =
164 platform_get_drvdata(pdev);
165
166 thermal_zone_device_unregister(dove_thermal);
167
168 return 0;
169 }
170
171 MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
172
173 static struct platform_driver dove_thermal_driver = {
174 .probe = dove_thermal_probe,
175 .remove = dove_thermal_exit,
176 .driver = {
177 .name = "dove_thermal",
178 .of_match_table = dove_thermal_id_table,
179 },
180 };
181
182 module_platform_driver(dove_thermal_driver);
183
184 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
185 MODULE_DESCRIPTION("Dove thermal driver");
186 MODULE_LICENSE("GPL");
187