Root/drivers/thermal/dove_thermal.c

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 */
46struct dove_thermal_priv {
47    void __iomem *sensor;
48    void __iomem *control;
49};
50
51static 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
95static 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    /*
110     * Calculate temperature. See Section 8.10.1 of 88AP510,
111     * Documentation/arm/Marvell/README
112     */
113    reg = readl_relaxed(priv->sensor);
114    reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
115    *temp = ((2281638UL - (7298*reg)) / 10);
116
117    return 0;
118}
119
120static struct thermal_zone_device_ops ops = {
121    .get_temp = dove_get_temp,
122};
123
124static const struct of_device_id dove_thermal_id_table[] = {
125    { .compatible = "marvell,dove-thermal" },
126    {}
127};
128
129static int dove_thermal_probe(struct platform_device *pdev)
130{
131    struct thermal_zone_device *thermal = NULL;
132    struct dove_thermal_priv *priv;
133    struct resource *res;
134    int ret;
135
136    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
137    if (!res) {
138        dev_err(&pdev->dev, "Failed to get platform resource\n");
139        return -ENODEV;
140    }
141
142    priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
143    if (!priv)
144        return -ENOMEM;
145
146    priv->sensor = devm_ioremap_resource(&pdev->dev, res);
147    if (IS_ERR(priv->sensor))
148        return PTR_ERR(priv->sensor);
149
150    res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
151    if (!res) {
152        dev_err(&pdev->dev, "Failed to get platform resource\n");
153        return -ENODEV;
154    }
155    priv->control = devm_ioremap_resource(&pdev->dev, res);
156    if (IS_ERR(priv->control))
157        return PTR_ERR(priv->control);
158
159    ret = dove_init_sensor(priv);
160    if (ret) {
161        dev_err(&pdev->dev, "Failed to initialize sensor\n");
162        return ret;
163    }
164
165    thermal = thermal_zone_device_register("dove_thermal", 0, 0,
166                           priv, &ops, NULL, 0, 0);
167    if (IS_ERR(thermal)) {
168        dev_err(&pdev->dev,
169            "Failed to register thermal zone device\n");
170        return PTR_ERR(thermal);
171    }
172
173    platform_set_drvdata(pdev, thermal);
174
175    return 0;
176}
177
178static int dove_thermal_exit(struct platform_device *pdev)
179{
180    struct thermal_zone_device *dove_thermal =
181        platform_get_drvdata(pdev);
182
183    thermal_zone_device_unregister(dove_thermal);
184    platform_set_drvdata(pdev, NULL);
185
186    return 0;
187}
188
189MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
190
191static struct platform_driver dove_thermal_driver = {
192    .probe = dove_thermal_probe,
193    .remove = dove_thermal_exit,
194    .driver = {
195        .name = "dove_thermal",
196        .owner = THIS_MODULE,
197        .of_match_table = of_match_ptr(dove_thermal_id_table),
198    },
199};
200
201module_platform_driver(dove_thermal_driver);
202
203MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
204MODULE_DESCRIPTION("Dove thermal driver");
205MODULE_LICENSE("GPL");
206

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