1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Broadcom
4  */
5 
6 #include <linux/module.h>
7 #include <linux/of_address.h>
8 #include <linux/platform_device.h>
9 #include <linux/thermal.h>
10 
11 /*
12  * In stingray thermal IO memory,
13  * Total Number of available TMONs MASK is at offset 0
14  * temperature registers BASE is at 4 byte offset.
15  * Each TMON temperature register size is 4.
16  */
17 #define SR_TMON_TEMP_BASE(id)   ((id) * 0x4)
18 
19 #define SR_TMON_MAX_LIST        6
20 
21 struct sr_tmon {
22 	struct thermal_zone_device *tz;
23 	unsigned int crit_temp;
24 	unsigned int tmon_id;
25 	struct sr_thermal *priv;
26 };
27 
28 struct sr_thermal {
29 	void __iomem *regs;
30 	unsigned int max_crit_temp;
31 	struct sr_tmon tmon[SR_TMON_MAX_LIST];
32 };
33 
34 static int sr_get_temp(void *data, int *temp)
35 {
36 	struct sr_tmon *tmon = data;
37 	struct sr_thermal *sr_thermal = tmon->priv;
38 
39 	*temp = readl(sr_thermal->regs + SR_TMON_TEMP_BASE(tmon->tmon_id));
40 
41 	return 0;
42 }
43 
44 static const struct thermal_zone_of_device_ops sr_tz_ops = {
45 	.get_temp = sr_get_temp,
46 };
47 
48 static int sr_thermal_probe(struct platform_device *pdev)
49 {
50 	struct device *dev = &pdev->dev;
51 	struct sr_thermal *sr_thermal;
52 	struct sr_tmon *tmon;
53 	struct resource *res;
54 	u32 sr_tmon_list = 0;
55 	unsigned int i;
56 	int ret;
57 
58 	sr_thermal = devm_kzalloc(dev, sizeof(*sr_thermal), GFP_KERNEL);
59 	if (!sr_thermal)
60 		return -ENOMEM;
61 
62 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
63 	if (!res)
64 		return -ENOENT;
65 
66 	sr_thermal->regs = (void __iomem *)devm_memremap(&pdev->dev, res->start,
67 							 resource_size(res),
68 							 MEMREMAP_WB);
69 	if (IS_ERR(sr_thermal->regs)) {
70 		dev_err(dev, "failed to get io address\n");
71 		return PTR_ERR(sr_thermal->regs);
72 	}
73 
74 	ret = device_property_read_u32(dev, "brcm,tmon-mask", &sr_tmon_list);
75 	if (ret)
76 		return ret;
77 
78 	tmon = sr_thermal->tmon;
79 	for (i = 0; i < SR_TMON_MAX_LIST; i++, tmon++) {
80 		if (!(sr_tmon_list & BIT(i)))
81 			continue;
82 
83 		/* Flush temperature registers */
84 		writel(0, sr_thermal->regs + SR_TMON_TEMP_BASE(i));
85 		tmon->tmon_id = i;
86 		tmon->priv = sr_thermal;
87 		tmon->tz = devm_thermal_zone_of_sensor_register(dev, i, tmon,
88 								&sr_tz_ops);
89 		if (IS_ERR(tmon->tz))
90 			return PTR_ERR(tmon->tz);
91 
92 		dev_dbg(dev, "thermal sensor %d registered\n", i);
93 	}
94 	platform_set_drvdata(pdev, sr_thermal);
95 
96 	return 0;
97 }
98 
99 static const struct of_device_id sr_thermal_of_match[] = {
100 	{ .compatible = "brcm,sr-thermal", },
101 	{},
102 };
103 MODULE_DEVICE_TABLE(of, sr_thermal_of_match);
104 
105 static struct platform_driver sr_thermal_driver = {
106 	.probe		= sr_thermal_probe,
107 	.driver = {
108 		.name = "sr-thermal",
109 		.of_match_table = sr_thermal_of_match,
110 	},
111 };
112 module_platform_driver(sr_thermal_driver);
113 
114 MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
115 MODULE_DESCRIPTION("Stingray thermal driver");
116 MODULE_LICENSE("GPL v2");
117