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74ffa64c AL |
1 | /* |
2 | * Dove thermal sensor driver | |
3 | * | |
4 | * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch> | |
5 | * | |
6 | * This software is licensed under the terms of the GNU General Public | |
7 | * License version 2, as published by the Free Software Foundation, and | |
8 | * may be copied, distributed, and modified under those terms. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | */ | |
16 | #include <linux/device.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/io.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/of.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/platform_device.h> | |
23 | #include <linux/thermal.h> | |
24 | ||
25 | #define DOVE_THERMAL_TEMP_OFFSET 1 | |
26 | #define DOVE_THERMAL_TEMP_MASK 0x1FF | |
27 | ||
28 | /* Dove Thermal Manager Control and Status Register */ | |
29 | #define PMU_TM_DISABLE_OFFS 0 | |
30 | #define PMU_TM_DISABLE_MASK (0x1 << PMU_TM_DISABLE_OFFS) | |
31 | ||
32 | /* Dove Theraml Diode Control 0 Register */ | |
33 | #define PMU_TDC0_SW_RST_MASK (0x1 << 1) | |
34 | #define PMU_TDC0_SEL_VCAL_OFFS 5 | |
35 | #define PMU_TDC0_SEL_VCAL_MASK (0x3 << PMU_TDC0_SEL_VCAL_OFFS) | |
36 | #define PMU_TDC0_REF_CAL_CNT_OFFS 11 | |
37 | #define PMU_TDC0_REF_CAL_CNT_MASK (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS) | |
38 | #define PMU_TDC0_AVG_NUM_OFFS 25 | |
39 | #define PMU_TDC0_AVG_NUM_MASK (0x7 << PMU_TDC0_AVG_NUM_OFFS) | |
40 | ||
41 | /* Dove Thermal Diode Control 1 Register */ | |
42 | #define PMU_TEMP_DIOD_CTRL1_REG 0x04 | |
43 | #define PMU_TDC1_TEMP_VALID_MASK (0x1 << 10) | |
44 | ||
45 | /* Dove Thermal Sensor Dev Structure */ | |
46 | struct dove_thermal_priv { | |
47 | void __iomem *sensor; | |
48 | void __iomem *control; | |
49 | }; | |
50 | ||
51 | static int dove_init_sensor(const struct dove_thermal_priv *priv) | |
52 | { | |
53 | u32 reg; | |
54 | u32 i; | |
55 | ||
56 | /* Configure the Diode Control Register #0 */ | |
57 | reg = readl_relaxed(priv->control); | |
58 | ||
59 | /* Use average of 2 */ | |
60 | reg &= ~PMU_TDC0_AVG_NUM_MASK; | |
61 | reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS); | |
62 | ||
63 | /* Reference calibration value */ | |
64 | reg &= ~PMU_TDC0_REF_CAL_CNT_MASK; | |
65 | reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS); | |
66 | ||
67 | /* Set the high level reference for calibration */ | |
68 | reg &= ~PMU_TDC0_SEL_VCAL_MASK; | |
69 | reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS); | |
70 | writel(reg, priv->control); | |
71 | ||
72 | /* Reset the sensor */ | |
73 | reg = readl_relaxed(priv->control); | |
74 | writel((reg | PMU_TDC0_SW_RST_MASK), priv->control); | |
75 | writel(reg, priv->control); | |
76 | ||
77 | /* Enable the sensor */ | |
78 | reg = readl_relaxed(priv->sensor); | |
79 | reg &= ~PMU_TM_DISABLE_MASK; | |
80 | writel(reg, priv->sensor); | |
81 | ||
82 | /* Poll the sensor for the first reading */ | |
83 | for (i = 0; i < 1000000; i++) { | |
84 | reg = readl_relaxed(priv->sensor); | |
85 | if (reg & DOVE_THERMAL_TEMP_MASK) | |
86 | break; | |
87 | } | |
88 | ||
89 | if (i == 1000000) | |
90 | return -EIO; | |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
95 | static int dove_get_temp(struct thermal_zone_device *thermal, | |
96 | unsigned long *temp) | |
97 | { | |
98 | unsigned long reg; | |
99 | struct dove_thermal_priv *priv = thermal->devdata; | |
100 | ||
101 | /* Valid check */ | |
102 | reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG); | |
103 | if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) { | |
104 | dev_err(&thermal->device, | |
105 | "Temperature sensor reading not valid\n"); | |
106 | return -EIO; | |
107 | } | |
108 | ||
109 | /* | |
2fd1db88 EG |
110 | * Calculate temperature. According to Marvell internal |
111 | * documentation the formula for this is: | |
112 | * Celsius = (322-reg)/1.3625 | |
74ffa64c AL |
113 | */ |
114 | reg = readl_relaxed(priv->sensor); | |
115 | reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK; | |
2fd1db88 | 116 | *temp = ((3220000000UL - (10000000UL * reg)) / 13625); |
74ffa64c AL |
117 | |
118 | return 0; | |
119 | } | |
120 | ||
121 | static struct thermal_zone_device_ops ops = { | |
122 | .get_temp = dove_get_temp, | |
123 | }; | |
124 | ||
125 | static const struct of_device_id dove_thermal_id_table[] = { | |
126 | { .compatible = "marvell,dove-thermal" }, | |
127 | {} | |
128 | }; | |
129 | ||
130 | static int dove_thermal_probe(struct platform_device *pdev) | |
131 | { | |
132 | struct thermal_zone_device *thermal = NULL; | |
133 | struct dove_thermal_priv *priv; | |
134 | struct resource *res; | |
135 | int ret; | |
136 | ||
74ffa64c AL |
137 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
138 | if (!priv) | |
139 | return -ENOMEM; | |
140 | ||
c28f692c | 141 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
6bc51b66 SK |
142 | priv->sensor = devm_ioremap_resource(&pdev->dev, res); |
143 | if (IS_ERR(priv->sensor)) | |
144 | return PTR_ERR(priv->sensor); | |
74ffa64c AL |
145 | |
146 | res = platform_get_resource(pdev, IORESOURCE_MEM, 1); | |
6bc51b66 SK |
147 | priv->control = devm_ioremap_resource(&pdev->dev, res); |
148 | if (IS_ERR(priv->control)) | |
149 | return PTR_ERR(priv->control); | |
74ffa64c AL |
150 | |
151 | ret = dove_init_sensor(priv); | |
152 | if (ret) { | |
153 | dev_err(&pdev->dev, "Failed to initialize sensor\n"); | |
154 | return ret; | |
155 | } | |
156 | ||
157 | thermal = thermal_zone_device_register("dove_thermal", 0, 0, | |
158 | priv, &ops, NULL, 0, 0); | |
159 | if (IS_ERR(thermal)) { | |
160 | dev_err(&pdev->dev, | |
161 | "Failed to register thermal zone device\n"); | |
162 | return PTR_ERR(thermal); | |
163 | } | |
164 | ||
165 | platform_set_drvdata(pdev, thermal); | |
166 | ||
167 | return 0; | |
168 | } | |
169 | ||
170 | static int dove_thermal_exit(struct platform_device *pdev) | |
171 | { | |
172 | struct thermal_zone_device *dove_thermal = | |
173 | platform_get_drvdata(pdev); | |
174 | ||
175 | thermal_zone_device_unregister(dove_thermal); | |
74ffa64c AL |
176 | |
177 | return 0; | |
178 | } | |
179 | ||
180 | MODULE_DEVICE_TABLE(of, dove_thermal_id_table); | |
181 | ||
182 | static struct platform_driver dove_thermal_driver = { | |
183 | .probe = dove_thermal_probe, | |
184 | .remove = dove_thermal_exit, | |
185 | .driver = { | |
186 | .name = "dove_thermal", | |
187 | .owner = THIS_MODULE, | |
e0d68afa | 188 | .of_match_table = dove_thermal_id_table, |
74ffa64c AL |
189 | }, |
190 | }; | |
191 | ||
192 | module_platform_driver(dove_thermal_driver); | |
193 | ||
194 | MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); | |
195 | MODULE_DESCRIPTION("Dove thermal driver"); | |
196 | MODULE_LICENSE("GPL"); |