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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SPEAr thermal driver.
4  *
5  * Copyright (C) 2011-2012 ST Microelectronics
6  * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/of.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/thermal.h>
18 
19 #define MD_FACTOR	1000
20 
21 /* SPEAr Thermal Sensor Dev Structure */
22 struct spear_thermal_dev {
23 	/* pointer to base address of the thermal sensor */
24 	void __iomem *thermal_base;
25 	/* clk structure */
26 	struct clk *clk;
27 	/* pointer to thermal flags */
28 	unsigned int flags;
29 };
30 
thermal_get_temp(struct thermal_zone_device * thermal,int * temp)31 static inline int thermal_get_temp(struct thermal_zone_device *thermal,
32 				int *temp)
33 {
34 	struct spear_thermal_dev *stdev = thermal->devdata;
35 
36 	/*
37 	 * Data are ready to be read after 628 usec from POWERDOWN signal
38 	 * (PDN) = 1
39 	 */
40 	*temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR;
41 	return 0;
42 }
43 
44 static struct thermal_zone_device_ops ops = {
45 	.get_temp = thermal_get_temp,
46 };
47 
spear_thermal_suspend(struct device * dev)48 static int __maybe_unused spear_thermal_suspend(struct device *dev)
49 {
50 	struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
51 	struct spear_thermal_dev *stdev = spear_thermal->devdata;
52 	unsigned int actual_mask = 0;
53 
54 	/* Disable SPEAr Thermal Sensor */
55 	actual_mask = readl_relaxed(stdev->thermal_base);
56 	writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
57 
58 	clk_disable(stdev->clk);
59 	dev_info(dev, "Suspended.\n");
60 
61 	return 0;
62 }
63 
spear_thermal_resume(struct device * dev)64 static int __maybe_unused spear_thermal_resume(struct device *dev)
65 {
66 	struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
67 	struct spear_thermal_dev *stdev = spear_thermal->devdata;
68 	unsigned int actual_mask = 0;
69 	int ret = 0;
70 
71 	ret = clk_enable(stdev->clk);
72 	if (ret) {
73 		dev_err(dev, "Can't enable clock\n");
74 		return ret;
75 	}
76 
77 	/* Enable SPEAr Thermal Sensor */
78 	actual_mask = readl_relaxed(stdev->thermal_base);
79 	writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base);
80 
81 	dev_info(dev, "Resumed.\n");
82 
83 	return 0;
84 }
85 
86 static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,
87 		spear_thermal_resume);
88 
spear_thermal_probe(struct platform_device * pdev)89 static int spear_thermal_probe(struct platform_device *pdev)
90 {
91 	struct thermal_zone_device *spear_thermal = NULL;
92 	struct spear_thermal_dev *stdev;
93 	struct device_node *np = pdev->dev.of_node;
94 	struct resource *res;
95 	int ret = 0, val;
96 
97 	if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
98 		dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
99 		return -EINVAL;
100 	}
101 
102 	stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
103 	if (!stdev)
104 		return -ENOMEM;
105 
106 	/* Enable thermal sensor */
107 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
108 	stdev->thermal_base = devm_ioremap_resource(&pdev->dev, res);
109 	if (IS_ERR(stdev->thermal_base))
110 		return PTR_ERR(stdev->thermal_base);
111 
112 	stdev->clk = devm_clk_get(&pdev->dev, NULL);
113 	if (IS_ERR(stdev->clk)) {
114 		dev_err(&pdev->dev, "Can't get clock\n");
115 		return PTR_ERR(stdev->clk);
116 	}
117 
118 	ret = clk_enable(stdev->clk);
119 	if (ret) {
120 		dev_err(&pdev->dev, "Can't enable clock\n");
121 		return ret;
122 	}
123 
124 	stdev->flags = val;
125 	writel_relaxed(stdev->flags, stdev->thermal_base);
126 
127 	spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0,
128 				stdev, &ops, NULL, 0, 0);
129 	if (IS_ERR(spear_thermal)) {
130 		dev_err(&pdev->dev, "thermal zone device is NULL\n");
131 		ret = PTR_ERR(spear_thermal);
132 		goto disable_clk;
133 	}
134 	ret = thermal_zone_device_enable(spear_thermal);
135 	if (ret) {
136 		dev_err(&pdev->dev, "Cannot enable thermal zone\n");
137 		goto unregister_tzd;
138 	}
139 
140 	platform_set_drvdata(pdev, spear_thermal);
141 
142 	dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n",
143 			stdev->thermal_base);
144 
145 	return 0;
146 
147 unregister_tzd:
148 	thermal_zone_device_unregister(spear_thermal);
149 disable_clk:
150 	clk_disable(stdev->clk);
151 
152 	return ret;
153 }
154 
spear_thermal_exit(struct platform_device * pdev)155 static int spear_thermal_exit(struct platform_device *pdev)
156 {
157 	unsigned int actual_mask = 0;
158 	struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
159 	struct spear_thermal_dev *stdev = spear_thermal->devdata;
160 
161 	thermal_zone_device_unregister(spear_thermal);
162 
163 	/* Disable SPEAr Thermal Sensor */
164 	actual_mask = readl_relaxed(stdev->thermal_base);
165 	writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
166 
167 	clk_disable(stdev->clk);
168 
169 	return 0;
170 }
171 
172 static const struct of_device_id spear_thermal_id_table[] = {
173 	{ .compatible = "st,thermal-spear1340" },
174 	{}
175 };
176 MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
177 
178 static struct platform_driver spear_thermal_driver = {
179 	.probe = spear_thermal_probe,
180 	.remove = spear_thermal_exit,
181 	.driver = {
182 		.name = "spear_thermal",
183 		.pm = &spear_thermal_pm_ops,
184 		.of_match_table = spear_thermal_id_table,
185 	},
186 };
187 
188 module_platform_driver(spear_thermal_driver);
189 
190 MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
191 MODULE_DESCRIPTION("SPEAr thermal driver");
192 MODULE_LICENSE("GPL");
193