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Vincenzo Frascino6a92c362012-03-21 12:55:03 -07001/*
2 * SPEAr thermal driver.
3 *
4 * Copyright (C) 2011-2012 ST Microelectronics
5 * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
6 *
7 * This software is licensed under the terms of the GNU General Public
8 * License version 2, as published by the Free Software Foundation, and
9 * may be copied, distributed, and modified under those terms.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 */
17
18#include <linux/clk.h>
19#include <linux/device.h>
20#include <linux/err.h>
21#include <linux/io.h>
22#include <linux/kernel.h>
Viresh Kumarb9c7aff2012-05-29 11:18:51 -070023#include <linux/of.h>
Vincenzo Frascino6a92c362012-03-21 12:55:03 -070024#include <linux/module.h>
25#include <linux/platform_device.h>
Vincenzo Frascino6a92c362012-03-21 12:55:03 -070026#include <linux/thermal.h>
27
28#define MD_FACTOR 1000
29
30/* SPEAr Thermal Sensor Dev Structure */
31struct spear_thermal_dev {
32 /* pointer to base address of the thermal sensor */
33 void __iomem *thermal_base;
34 /* clk structure */
35 struct clk *clk;
36 /* pointer to thermal flags */
37 unsigned int flags;
38};
39
40static inline int thermal_get_temp(struct thermal_zone_device *thermal,
41 unsigned long *temp)
42{
43 struct spear_thermal_dev *stdev = thermal->devdata;
44
45 /*
46 * Data are ready to be read after 628 usec from POWERDOWN signal
47 * (PDN) = 1
48 */
Viresh Kumarde716e32012-03-21 12:55:03 -070049 *temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR;
Vincenzo Frascino6a92c362012-03-21 12:55:03 -070050 return 0;
51}
52
53static struct thermal_zone_device_ops ops = {
54 .get_temp = thermal_get_temp,
55};
56
57#ifdef CONFIG_PM
58static int spear_thermal_suspend(struct device *dev)
59{
60 struct platform_device *pdev = to_platform_device(dev);
61 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
62 struct spear_thermal_dev *stdev = spear_thermal->devdata;
63 unsigned int actual_mask = 0;
64
65 /* Disable SPEAr Thermal Sensor */
Viresh Kumarde716e32012-03-21 12:55:03 -070066 actual_mask = readl_relaxed(stdev->thermal_base);
67 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
Vincenzo Frascino6a92c362012-03-21 12:55:03 -070068
69 clk_disable(stdev->clk);
70 dev_info(dev, "Suspended.\n");
71
72 return 0;
73}
74
75static int spear_thermal_resume(struct device *dev)
76{
77 struct platform_device *pdev = to_platform_device(dev);
78 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
79 struct spear_thermal_dev *stdev = spear_thermal->devdata;
80 unsigned int actual_mask = 0;
81 int ret = 0;
82
83 ret = clk_enable(stdev->clk);
84 if (ret) {
85 dev_err(&pdev->dev, "Can't enable clock\n");
86 return ret;
87 }
88
89 /* Enable SPEAr Thermal Sensor */
Viresh Kumarde716e32012-03-21 12:55:03 -070090 actual_mask = readl_relaxed(stdev->thermal_base);
91 writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base);
Vincenzo Frascino6a92c362012-03-21 12:55:03 -070092
93 dev_info(dev, "Resumed.\n");
94
95 return 0;
96}
97#endif
98
99static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,
100 spear_thermal_resume);
101
102static int spear_thermal_probe(struct platform_device *pdev)
103{
104 struct thermal_zone_device *spear_thermal = NULL;
105 struct spear_thermal_dev *stdev;
Viresh Kumarb9c7aff2012-05-29 11:18:51 -0700106 struct device_node *np = pdev->dev.of_node;
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700107 struct resource *stres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Viresh Kumarb9c7aff2012-05-29 11:18:51 -0700108 int ret = 0, val;
109
110 if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
111 dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
112 return -EINVAL;
113 }
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700114
115 if (!stres) {
116 dev_err(&pdev->dev, "memory resource missing\n");
117 return -ENODEV;
118 }
119
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700120 stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
121 if (!stdev) {
122 dev_err(&pdev->dev, "kzalloc fail\n");
123 return -ENOMEM;
124 }
125
126 /* Enable thermal sensor */
127 stdev->thermal_base = devm_ioremap(&pdev->dev, stres->start,
128 resource_size(stres));
129 if (!stdev->thermal_base) {
130 dev_err(&pdev->dev, "ioremap failed\n");
131 return -ENOMEM;
132 }
133
134 stdev->clk = clk_get(&pdev->dev, NULL);
135 if (IS_ERR(stdev->clk)) {
136 dev_err(&pdev->dev, "Can't get clock\n");
137 return PTR_ERR(stdev->clk);
138 }
139
140 ret = clk_enable(stdev->clk);
141 if (ret) {
142 dev_err(&pdev->dev, "Can't enable clock\n");
143 goto put_clk;
144 }
145
Viresh Kumarb9c7aff2012-05-29 11:18:51 -0700146 stdev->flags = val;
Viresh Kumarde716e32012-03-21 12:55:03 -0700147 writel_relaxed(stdev->flags, stdev->thermal_base);
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700148
Durgadoss Rc56f5c02012-07-25 10:10:58 +0800149 spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0,
Durgadoss R50125a92012-09-18 11:04:56 +0530150 stdev, &ops, NULL, 0, 0);
Dan Carpenter03ee62f2012-03-21 12:55:04 -0700151 if (IS_ERR(spear_thermal)) {
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700152 dev_err(&pdev->dev, "thermal zone device is NULL\n");
Dan Carpenter03ee62f2012-03-21 12:55:04 -0700153 ret = PTR_ERR(spear_thermal);
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700154 goto disable_clk;
155 }
156
157 platform_set_drvdata(pdev, spear_thermal);
158
159 dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n",
160 stdev->thermal_base);
161
162 return 0;
163
164disable_clk:
165 clk_disable(stdev->clk);
166put_clk:
167 clk_put(stdev->clk);
168
169 return ret;
170}
171
172static int spear_thermal_exit(struct platform_device *pdev)
173{
174 unsigned int actual_mask = 0;
175 struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
176 struct spear_thermal_dev *stdev = spear_thermal->devdata;
177
178 thermal_zone_device_unregister(spear_thermal);
179 platform_set_drvdata(pdev, NULL);
180
181 /* Disable SPEAr Thermal Sensor */
Viresh Kumarde716e32012-03-21 12:55:03 -0700182 actual_mask = readl_relaxed(stdev->thermal_base);
183 writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700184
185 clk_disable(stdev->clk);
186 clk_put(stdev->clk);
187
188 return 0;
189}
190
Viresh Kumarb9c7aff2012-05-29 11:18:51 -0700191static const struct of_device_id spear_thermal_id_table[] = {
192 { .compatible = "st,thermal-spear1340" },
193 {}
194};
195MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
196
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700197static struct platform_driver spear_thermal_driver = {
198 .probe = spear_thermal_probe,
199 .remove = spear_thermal_exit,
200 .driver = {
201 .name = "spear_thermal",
202 .owner = THIS_MODULE,
203 .pm = &spear_thermal_pm_ops,
Viresh Kumarb9c7aff2012-05-29 11:18:51 -0700204 .of_match_table = of_match_ptr(spear_thermal_id_table),
Vincenzo Frascino6a92c362012-03-21 12:55:03 -0700205 },
206};
207
208module_platform_driver(spear_thermal_driver);
209
210MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
211MODULE_DESCRIPTION("SPEAr thermal driver");
212MODULE_LICENSE("GPL");