drivers/thermal/broadcom/sr-thermal.c

   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
  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
  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");