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 	unsigned int crit_temp;
23 	unsigned int tmon_id;
24 	struct sr_thermal *priv;
25 };
26 
27 struct sr_thermal {
28 	void __iomem *regs;
29 	unsigned int max_crit_temp;
30 	struct sr_tmon tmon[SR_TMON_MAX_LIST];
31 };
32 
sr_get_temp(struct thermal_zone_device * tz,int * temp)33 static int sr_get_temp(struct thermal_zone_device *tz, int *temp)
34 {
35 	struct sr_tmon *tmon = thermal_zone_device_priv(tz);
36 	struct sr_thermal *sr_thermal = tmon->priv;
37 
38 	*temp = readl(sr_thermal->regs + SR_TMON_TEMP_BASE(tmon->tmon_id));
39 
40 	return 0;
41 }
42 
43 static const struct thermal_zone_device_ops sr_tz_ops = {
44 	.get_temp = sr_get_temp,
45 };
46 
sr_thermal_probe(struct platform_device * pdev)47 static int sr_thermal_probe(struct platform_device *pdev)
48 {
49 	struct device *dev = &pdev->dev;
50 	struct thermal_zone_device *tz;
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 		tz = devm_thermal_of_zone_register(dev, i, tmon,
88 						   &sr_tz_ops);
89 		if (IS_ERR(tz))
90 			return PTR_ERR(tz);
91 
92 		dev_dbg(dev, "thermal sensor %d registered\n", i);
93 	}
94 
95 	return 0;
96 }
97 
98 static const struct of_device_id sr_thermal_of_match[] = {
99 	{ .compatible = "brcm,sr-thermal", },
100 	{},
101 };
102 MODULE_DEVICE_TABLE(of, sr_thermal_of_match);
103 
104 static struct platform_driver sr_thermal_driver = {
105 	.probe		= sr_thermal_probe,
106 	.driver = {
107 		.name = "sr-thermal",
108 		.of_match_table = sr_thermal_of_match,
109 	},
110 };
111 module_platform_driver(sr_thermal_driver);
112 
113 MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
114 MODULE_DESCRIPTION("Stingray thermal driver");
115 MODULE_LICENSE("GPL v2");
116